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riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2020 SiFive
*/
#ifndef __ASM_RISCV_VECTOR_H
#define __ASM_RISCV_VECTOR_H
#include <linux/types.h>
riscv: Introduce riscv_v_vsize to record size of Vector context This patch is used to detect the size of CPU vector registers and use riscv_v_vsize to save the size of all the vector registers. It assumes all harts has the same capabilities in a SMP system. If a core detects VLENB that is different from the boot core, then it warns and turns off V support for user space. Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:05 +00:00
#include <uapi/asm-generic/errno.h>
riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
#ifdef CONFIG_RISCV_ISA_V
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
#include <linux/stringify.h>
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <asm/ptrace.h>
riscv: Rearrange hwcap.h and cpufeature.h Now hwcap.h and cpufeature.h are mutually including each other, and most of the variable/API declarations in hwcap.h are implemented in cpufeature.c, so, it's better to move them into cpufeature.h and leave only macros for ISA extension logical IDs in hwcap.h. BTW, the riscv_isa_extension_mask macro is not used now, so this patch removes it. Suggested-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Xiao Wang <xiao.w.wang@intel.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20231031064553.2319688-2-xiao.w.wang@intel.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-31 14:45:52 +08:00
#include <asm/cpufeature.h>
riscv: Introduce Vector enable/disable helpers These are small and likely to be frequently called so implement as inline routines (vs. function call). Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-8-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:04 +00:00
#include <asm/csr.h>
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
#include <asm/asm.h>
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
#include <asm/vendorid_list.h>
#include <asm/vendor_extensions.h>
#include <asm/vendor_extensions/thead.h>
#define __riscv_v_vstate_or(_val, TYPE) ({ \
typeof(_val) _res = _val; \
if (has_xtheadvector()) \
_res = (_res & ~SR_VS_THEAD) | SR_VS_##TYPE##_THEAD; \
else \
_res = (_res & ~SR_VS) | SR_VS_##TYPE; \
_res; \
})
#define __riscv_v_vstate_check(_val, TYPE) ({ \
bool _res; \
if (has_xtheadvector()) \
_res = ((_val) & SR_VS_THEAD) == SR_VS_##TYPE##_THEAD; \
else \
_res = ((_val) & SR_VS) == SR_VS_##TYPE; \
_res; \
})
riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
riscv: Introduce riscv_v_vsize to record size of Vector context This patch is used to detect the size of CPU vector registers and use riscv_v_vsize to save the size of all the vector registers. It assumes all harts has the same capabilities in a SMP system. If a core detects VLENB that is different from the boot core, then it warns and turns off V support for user space. Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:05 +00:00
extern unsigned long riscv_v_vsize;
int riscv_v_setup_vsize(void);
RISC-V: Detect unaligned vector accesses supported Run an unaligned vector access to test if the system supports vector unaligned access. Add the result to a new key in hwprobe. This is useful for usermode to know if vector misaligned accesses are supported and if they are faster or slower than equivalent byte accesses. Signed-off-by: Jesse Taube <jesse@rivosinc.com> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20241017-jesse_unaligned_vector-v10-4-5b33500160f8@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-17 12:00:21 -07:00
bool insn_is_vector(u32 insn_buf);
riscv: Allocate user's vector context in the first-use trap Vector unit is disabled by default for all user processes. Thus, a process will take a trap (illegal instruction) into kernel at the first time when it uses Vector. Only after then, the kernel allocates V context and starts take care of the context for that user process. Suggested-by: Richard Henderson <richard.henderson@linaro.org> Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230605110724.21391-12-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:08 +00:00
bool riscv_v_first_use_handler(struct pt_regs *regs);
riscv: Add support for kernel mode vector Add kernel_vector_begin() and kernel_vector_end() function declarations and corresponding definitions in kernel_mode_vector.c These are needed to wrap uses of vector in kernel mode. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-2-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:20 +00:00
void kernel_vector_begin(void);
void kernel_vector_end(void);
void get_cpu_vector_context(void);
void put_cpu_vector_context(void);
riscv: vector: use kmem_cache to manage vector context The allocation size of thread.vstate.datap is always riscv_v_vsize. So it is possbile to use kmem_cache_* to manage the allocation. This gives users more information regarding allocation of vector context via /proc/slabinfo. And it potentially reduces the latency of the first-use trap because of the allocation caches. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:28 +00:00
void riscv_v_thread_free(struct task_struct *tsk);
void __init riscv_v_setup_ctx_cache(void);
riscv: vector: allow kernel-mode Vector with preemption Add kernel_vstate to keep track of kernel-mode Vector registers when trap introduced context switch happens. Also, provide riscv_v_flags to let context save/restore routine track context status. Context tracking happens whenever the core starts its in-kernel Vector executions. An active (dirty) kernel task's V contexts will be saved to memory whenever a trap-introduced context switch happens. Or, when a softirq, which happens to nest on top of it, uses Vector. Context retoring happens when the execution transfer back to the original Kernel context where it first enable preempt_v. Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an option to disable preemptible kernel-mode Vector at build time. Users with constraint memory may want to disable this config as preemptible kernel-mode Vector needs extra space for tracking of per thread's kernel-mode V context. Or, users might as well want to disable it if all kernel-mode Vector code is time sensitive and cannot tolerate context switch overhead. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:29 +00:00
void riscv_v_thread_alloc(struct task_struct *tsk);
riscv: Add support for kernel mode vector Add kernel_vector_begin() and kernel_vector_end() function declarations and corresponding definitions in kernel_mode_vector.c These are needed to wrap uses of vector in kernel mode. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-2-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:20 +00:00
static inline u32 riscv_v_flags(void)
{
riscv: vector: allow kernel-mode Vector with preemption Add kernel_vstate to keep track of kernel-mode Vector registers when trap introduced context switch happens. Also, provide riscv_v_flags to let context save/restore routine track context status. Context tracking happens whenever the core starts its in-kernel Vector executions. An active (dirty) kernel task's V contexts will be saved to memory whenever a trap-introduced context switch happens. Or, when a softirq, which happens to nest on top of it, uses Vector. Context retoring happens when the execution transfer back to the original Kernel context where it first enable preempt_v. Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an option to disable preemptible kernel-mode Vector at build time. Users with constraint memory may want to disable this config as preemptible kernel-mode Vector needs extra space for tracking of per thread's kernel-mode V context. Or, users might as well want to disable it if all kernel-mode Vector code is time sensitive and cannot tolerate context switch overhead. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:29 +00:00
return READ_ONCE(current->thread.riscv_v_flags);
riscv: Add support for kernel mode vector Add kernel_vector_begin() and kernel_vector_end() function declarations and corresponding definitions in kernel_mode_vector.c These are needed to wrap uses of vector in kernel mode. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-2-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:20 +00:00
}
riscv: Introduce riscv_v_vsize to record size of Vector context This patch is used to detect the size of CPU vector registers and use riscv_v_vsize to save the size of all the vector registers. It assumes all harts has the same capabilities in a SMP system. If a core detects VLENB that is different from the boot core, then it warns and turns off V support for user space. Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:05 +00:00
riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
static __always_inline bool has_vector(void)
{
riscv: vector: adjust minimum Vector requirement to ZVE32X Make has_vector() to check for ZVE32X. Every in-kernel usage of V that requires a more complicate version of V must then call out explicitly. Also, change riscv_v_first_use_handler(), and boot code that calls riscv_v_setup_vsize() to accept ZVE32X. Most kernel/user interfaces requires minimum of ZVE32X. Thus, programs compiled and run with ZVE32X should be supported by the kernel on most aspects. This includes context-switch, signal, ptrace, prctl, and hwprobe. One exception is that ELF_HWCAP returns 'V' only if full V is supported on the platform. This means that the system without a full V must not rely on ELF_HWCAP to tell whether it is allowable to execute Vector without first invoking a prctl() check. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Joel Granados <j.granados@samsung.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-7-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-10 00:26:57 +08:00
return riscv_has_extension_unlikely(RISCV_ISA_EXT_ZVE32X);
riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
}
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
static __always_inline bool has_xtheadvector_no_alternatives(void)
{
if (IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
return riscv_isa_vendor_extension_available(THEAD_VENDOR_ID, XTHEADVECTOR);
else
return false;
}
static __always_inline bool has_xtheadvector(void)
{
if (IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
return riscv_has_vendor_extension_unlikely(THEAD_VENDOR_ID,
RISCV_ISA_VENDOR_EXT_XTHEADVECTOR);
else
return false;
}
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
regs->status = __riscv_v_vstate_or(regs->status, CLEAN);
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
}
riscv: Discard vector state on syscalls The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-29 16:22:28 +02:00
static inline void __riscv_v_vstate_dirty(struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
regs->status = __riscv_v_vstate_or(regs->status, DIRTY);
riscv: Discard vector state on syscalls The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-29 16:22:28 +02:00
}
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
static inline void riscv_v_vstate_off(struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
regs->status = __riscv_v_vstate_or(regs->status, OFF);
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
}
static inline void riscv_v_vstate_on(struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
regs->status = __riscv_v_vstate_or(regs->status, INITIAL);
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
}
static inline bool riscv_v_vstate_query(struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
return !__riscv_v_vstate_check(regs->status, OFF);
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
}
riscv: Introduce Vector enable/disable helpers These are small and likely to be frequently called so implement as inline routines (vs. function call). Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-8-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:04 +00:00
static __always_inline void riscv_v_enable(void)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (has_xtheadvector())
csr_set(CSR_SSTATUS, SR_VS_THEAD);
else
csr_set(CSR_SSTATUS, SR_VS);
riscv: Introduce Vector enable/disable helpers These are small and likely to be frequently called so implement as inline routines (vs. function call). Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-8-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:04 +00:00
}
static __always_inline void riscv_v_disable(void)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (has_xtheadvector())
csr_clear(CSR_SSTATUS, SR_VS_THEAD);
else
csr_clear(CSR_SSTATUS, SR_VS);
riscv: Introduce Vector enable/disable helpers These are small and likely to be frequently called so implement as inline routines (vs. function call). Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-8-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:04 +00:00
}
riscv: vector: Support calling schedule() for preemptible Vector Each function entry implies a call to ftrace infrastructure. And it may call into schedule in some cases. So, it is possible for preemptible kernel-mode Vector to implicitly call into schedule. Since all V-regs are caller-saved, it is possible to drop all V context when a thread voluntarily call schedule(). Besides, we currently don't pass argument through vector register, so we don't have to save/restore V-regs in ftrace trampoline. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20250407180838.42877-7-andybnac@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-04-08 02:08:31 +08:00
static __always_inline bool riscv_v_is_on(void)
{
return !!(csr_read(CSR_SSTATUS) & SR_VS);
}
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
{
asm volatile (
"csrr %0, " __stringify(CSR_VSTART) "\n\t"
"csrr %1, " __stringify(CSR_VTYPE) "\n\t"
"csrr %2, " __stringify(CSR_VL) "\n\t"
: "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl),
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
"=r" (dest->vcsr) : :);
if (has_xtheadvector()) {
unsigned long status;
/*
* CSR_VCSR is defined as
* [2:1] - vxrm[1:0]
* [0] - vxsat
* The earlier vector spec implemented by T-Head uses separate
* registers for the same bit-elements, so just combine those
* into the existing output field.
*
* Additionally T-Head cores need FS to be enabled when accessing
* the VXRM and VXSAT CSRs, otherwise ending in illegal instructions.
* Though the cores do not implement the VXRM and VXSAT fields in the
* FCSR CSR that vector-0.7.1 specifies.
*/
status = csr_read_set(CSR_STATUS, SR_FS_DIRTY);
dest->vcsr = csr_read(CSR_VXSAT) | csr_read(CSR_VXRM) << CSR_VXRM_SHIFT;
dest->vlenb = riscv_v_vsize / 32;
if ((status & SR_FS) != SR_FS_DIRTY)
csr_write(CSR_STATUS, status);
} else {
dest->vcsr = csr_read(CSR_VCSR);
dest->vlenb = csr_read(CSR_VLENB);
}
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
}
static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src)
{
asm volatile (
".option push\n\t"
riscv: vector: adjust minimum Vector requirement to ZVE32X Make has_vector() to check for ZVE32X. Every in-kernel usage of V that requires a more complicate version of V must then call out explicitly. Also, change riscv_v_first_use_handler(), and boot code that calls riscv_v_setup_vsize() to accept ZVE32X. Most kernel/user interfaces requires minimum of ZVE32X. Thus, programs compiled and run with ZVE32X should be supported by the kernel on most aspects. This includes context-switch, signal, ptrace, prctl, and hwprobe. One exception is that ELF_HWCAP returns 'V' only if full V is supported on the platform. This means that the system without a full V must not rely on ELF_HWCAP to tell whether it is allowable to execute Vector without first invoking a prctl() check. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Joel Granados <j.granados@samsung.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-7-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-10 00:26:57 +08:00
".option arch, +zve32x\n\t"
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
"vsetvl x0, %2, %1\n\t"
".option pop\n\t"
"csrw " __stringify(CSR_VSTART) ", %0\n\t"
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
: : "r" (src->vstart), "r" (src->vtype), "r" (src->vl));
if (has_xtheadvector()) {
unsigned long status = csr_read(CSR_SSTATUS);
/*
* Similar to __vstate_csr_save above, restore values for the
* separate VXRM and VXSAT CSRs from the vcsr variable.
*/
status = csr_read_set(CSR_STATUS, SR_FS_DIRTY);
csr_write(CSR_VXRM, (src->vcsr >> CSR_VXRM_SHIFT) & CSR_VXRM_MASK);
csr_write(CSR_VXSAT, src->vcsr & CSR_VXSAT_MASK);
if ((status & SR_FS) != SR_FS_DIRTY)
csr_write(CSR_STATUS, status);
} else {
csr_write(CSR_VCSR, src->vcsr);
}
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
}
static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
void *datap)
{
unsigned long vl;
riscv_v_enable();
__vstate_csr_save(save_to);
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (has_xtheadvector()) {
asm volatile (
"mv t0, %0\n\t"
THEAD_VSETVLI_T4X0E8M8D1
THEAD_VSB_V_V0T0
"add t0, t0, t4\n\t"
riscv: vector: Fix context save/restore with xtheadvector Previously only v0-v7 were correctly saved/restored, and the context of v8-v31 are damanged. Correctly save/restore v8-v31 to avoid breaking userspace. Fixes: d863910eabaf ("riscv: vector: Support xtheadvector save/restore") Cc: stable@vger.kernel.org Signed-off-by: Han Gao <rabenda.cn@gmail.com> Tested-by: Xiongchuan Tan <tanxiongchuan@isrc.iscas.ac.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Yanteng Si <si.yanteng@linux.dev> Reviewed-by: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/r/9b9eb2337f3d5336ce813721f8ebea51e0b2b553.1747994822.git.rabenda.cn@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-05-23 18:25:56 +08:00
THEAD_VSB_V_V8T0
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
"add t0, t0, t4\n\t"
riscv: vector: Fix context save/restore with xtheadvector Previously only v0-v7 were correctly saved/restored, and the context of v8-v31 are damanged. Correctly save/restore v8-v31 to avoid breaking userspace. Fixes: d863910eabaf ("riscv: vector: Support xtheadvector save/restore") Cc: stable@vger.kernel.org Signed-off-by: Han Gao <rabenda.cn@gmail.com> Tested-by: Xiongchuan Tan <tanxiongchuan@isrc.iscas.ac.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Yanteng Si <si.yanteng@linux.dev> Reviewed-by: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/r/9b9eb2337f3d5336ce813721f8ebea51e0b2b553.1747994822.git.rabenda.cn@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-05-23 18:25:56 +08:00
THEAD_VSB_V_V16T0
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
"add t0, t0, t4\n\t"
riscv: vector: Fix context save/restore with xtheadvector Previously only v0-v7 were correctly saved/restored, and the context of v8-v31 are damanged. Correctly save/restore v8-v31 to avoid breaking userspace. Fixes: d863910eabaf ("riscv: vector: Support xtheadvector save/restore") Cc: stable@vger.kernel.org Signed-off-by: Han Gao <rabenda.cn@gmail.com> Tested-by: Xiongchuan Tan <tanxiongchuan@isrc.iscas.ac.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Yanteng Si <si.yanteng@linux.dev> Reviewed-by: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/r/9b9eb2337f3d5336ce813721f8ebea51e0b2b553.1747994822.git.rabenda.cn@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-05-23 18:25:56 +08:00
THEAD_VSB_V_V24T0
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
: : "r" (datap) : "memory", "t0", "t4");
} else {
asm volatile (
".option push\n\t"
".option arch, +zve32x\n\t"
"vsetvli %0, x0, e8, m8, ta, ma\n\t"
"vse8.v v0, (%1)\n\t"
"add %1, %1, %0\n\t"
"vse8.v v8, (%1)\n\t"
"add %1, %1, %0\n\t"
"vse8.v v16, (%1)\n\t"
"add %1, %1, %0\n\t"
"vse8.v v24, (%1)\n\t"
".option pop\n\t"
: "=&r" (vl) : "r" (datap) : "memory");
}
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
riscv_v_disable();
}
static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_from,
void *datap)
{
unsigned long vl;
riscv_v_enable();
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (has_xtheadvector()) {
asm volatile (
"mv t0, %0\n\t"
THEAD_VSETVLI_T4X0E8M8D1
THEAD_VLB_V_V0T0
"add t0, t0, t4\n\t"
riscv: vector: Fix context save/restore with xtheadvector Previously only v0-v7 were correctly saved/restored, and the context of v8-v31 are damanged. Correctly save/restore v8-v31 to avoid breaking userspace. Fixes: d863910eabaf ("riscv: vector: Support xtheadvector save/restore") Cc: stable@vger.kernel.org Signed-off-by: Han Gao <rabenda.cn@gmail.com> Tested-by: Xiongchuan Tan <tanxiongchuan@isrc.iscas.ac.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Yanteng Si <si.yanteng@linux.dev> Reviewed-by: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/r/9b9eb2337f3d5336ce813721f8ebea51e0b2b553.1747994822.git.rabenda.cn@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-05-23 18:25:56 +08:00
THEAD_VLB_V_V8T0
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
"add t0, t0, t4\n\t"
riscv: vector: Fix context save/restore with xtheadvector Previously only v0-v7 were correctly saved/restored, and the context of v8-v31 are damanged. Correctly save/restore v8-v31 to avoid breaking userspace. Fixes: d863910eabaf ("riscv: vector: Support xtheadvector save/restore") Cc: stable@vger.kernel.org Signed-off-by: Han Gao <rabenda.cn@gmail.com> Tested-by: Xiongchuan Tan <tanxiongchuan@isrc.iscas.ac.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Yanteng Si <si.yanteng@linux.dev> Reviewed-by: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/r/9b9eb2337f3d5336ce813721f8ebea51e0b2b553.1747994822.git.rabenda.cn@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-05-23 18:25:56 +08:00
THEAD_VLB_V_V16T0
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
"add t0, t0, t4\n\t"
riscv: vector: Fix context save/restore with xtheadvector Previously only v0-v7 were correctly saved/restored, and the context of v8-v31 are damanged. Correctly save/restore v8-v31 to avoid breaking userspace. Fixes: d863910eabaf ("riscv: vector: Support xtheadvector save/restore") Cc: stable@vger.kernel.org Signed-off-by: Han Gao <rabenda.cn@gmail.com> Tested-by: Xiongchuan Tan <tanxiongchuan@isrc.iscas.ac.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Yanteng Si <si.yanteng@linux.dev> Reviewed-by: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/r/9b9eb2337f3d5336ce813721f8ebea51e0b2b553.1747994822.git.rabenda.cn@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-05-23 18:25:56 +08:00
THEAD_VLB_V_V24T0
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
: : "r" (datap) : "memory", "t0", "t4");
} else {
asm volatile (
".option push\n\t"
".option arch, +zve32x\n\t"
"vsetvli %0, x0, e8, m8, ta, ma\n\t"
"vle8.v v0, (%1)\n\t"
"add %1, %1, %0\n\t"
"vle8.v v8, (%1)\n\t"
"add %1, %1, %0\n\t"
"vle8.v v16, (%1)\n\t"
"add %1, %1, %0\n\t"
"vle8.v v24, (%1)\n\t"
".option pop\n\t"
: "=&r" (vl) : "r" (datap) : "memory");
}
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
__vstate_csr_restore(restore_from);
riscv_v_disable();
}
riscv: Discard vector state on syscalls The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-29 16:22:28 +02:00
static inline void __riscv_v_vstate_discard(void)
{
unsigned long vl, vtype_inval = 1UL << (BITS_PER_LONG - 1);
riscv_v_enable();
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (has_xtheadvector())
asm volatile (THEAD_VSETVLI_T4X0E8M8D1 : : : "t4");
else
asm volatile (
".option push\n\t"
".option arch, +zve32x\n\t"
"vsetvli %0, x0, e8, m8, ta, ma\n\t"
".option pop\n\t": "=&r" (vl));
riscv: Discard vector state on syscalls The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-29 16:22:28 +02:00
asm volatile (
".option push\n\t"
riscv: vector: adjust minimum Vector requirement to ZVE32X Make has_vector() to check for ZVE32X. Every in-kernel usage of V that requires a more complicate version of V must then call out explicitly. Also, change riscv_v_first_use_handler(), and boot code that calls riscv_v_setup_vsize() to accept ZVE32X. Most kernel/user interfaces requires minimum of ZVE32X. Thus, programs compiled and run with ZVE32X should be supported by the kernel on most aspects. This includes context-switch, signal, ptrace, prctl, and hwprobe. One exception is that ELF_HWCAP returns 'V' only if full V is supported on the platform. This means that the system without a full V must not rely on ELF_HWCAP to tell whether it is allowable to execute Vector without first invoking a prctl() check. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Joel Granados <j.granados@samsung.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-7-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-10 00:26:57 +08:00
".option arch, +zve32x\n\t"
riscv: Discard vector state on syscalls The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-29 16:22:28 +02:00
"vmv.v.i v0, -1\n\t"
"vmv.v.i v8, -1\n\t"
"vmv.v.i v16, -1\n\t"
"vmv.v.i v24, -1\n\t"
"vsetvl %0, x0, %1\n\t"
".option pop\n\t"
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
: "=&r" (vl) : "r" (vtype_inval));
riscv: Discard vector state on syscalls The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-29 16:22:28 +02:00
riscv_v_disable();
}
static inline void riscv_v_vstate_discard(struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (riscv_v_vstate_query(regs)) {
__riscv_v_vstate_discard();
__riscv_v_vstate_dirty(regs);
}
riscv: Discard vector state on syscalls The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-29 16:22:28 +02:00
}
riscv: vector: do not pass task_struct into riscv_v_vstate_{save,restore}() riscv_v_vstate_{save,restore}() can operate only on the knowlege of struct __riscv_v_ext_state, and struct pt_regs. Let the caller decides which should be passed into the function. Meanwhile, the kernel-mode Vector is going to introduce another vstate, so this also makes functions potentially able to be reused. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-8-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:26 +00:00
static inline void riscv_v_vstate_save(struct __riscv_v_ext_state *vstate,
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (__riscv_v_vstate_check(regs->status, DIRTY)) {
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
__riscv_v_vstate_save(vstate, vstate->datap);
__riscv_v_vstate_clean(regs);
}
}
riscv: vector: do not pass task_struct into riscv_v_vstate_{save,restore}() riscv_v_vstate_{save,restore}() can operate only on the knowlege of struct __riscv_v_ext_state, and struct pt_regs. Let the caller decides which should be passed into the function. Meanwhile, the kernel-mode Vector is going to introduce another vstate, so this also makes functions potentially able to be reused. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-8-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:26 +00:00
static inline void riscv_v_vstate_restore(struct __riscv_v_ext_state *vstate,
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (riscv_v_vstate_query(regs)) {
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
__riscv_v_vstate_restore(vstate, vstate->datap);
__riscv_v_vstate_clean(regs);
}
}
riscv: sched: defer restoring Vector context for user User will use its Vector registers only after the kernel really returns to the userspace. So we can delay restoring Vector registers as long as we are still running in kernel mode. So, add a thread flag to indicates the need of restoring Vector and do the restore at the last arch-specific exit-to-user hook. This save the context restoring cost when we switch over multiple processes that run V in kernel mode. For example, if the kernel performs a context swicth from A->B->C, and returns to C's userspace, then there is no need to restore B's V-register. Besides, this also prevents us from repeatedly restoring V context when executing kernel-mode Vector multiple times. The cost of this is that we must disable preemption and mark vector as busy during vstate_{save,restore}. Because then the V context will not get restored back immediately when a trap-causing context switch happens in the middle of vstate_{save,restore}. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-5-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:23 +00:00
static inline void riscv_v_vstate_set_restore(struct task_struct *task,
struct pt_regs *regs)
{
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
if (riscv_v_vstate_query(regs)) {
riscv: sched: defer restoring Vector context for user User will use its Vector registers only after the kernel really returns to the userspace. So we can delay restoring Vector registers as long as we are still running in kernel mode. So, add a thread flag to indicates the need of restoring Vector and do the restore at the last arch-specific exit-to-user hook. This save the context restoring cost when we switch over multiple processes that run V in kernel mode. For example, if the kernel performs a context swicth from A->B->C, and returns to C's userspace, then there is no need to restore B's V-register. Besides, this also prevents us from repeatedly restoring V context when executing kernel-mode Vector multiple times. The cost of this is that we must disable preemption and mark vector as busy during vstate_{save,restore}. Because then the V context will not get restored back immediately when a trap-causing context switch happens in the middle of vstate_{save,restore}. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-5-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:23 +00:00
set_tsk_thread_flag(task, TIF_RISCV_V_DEFER_RESTORE);
riscv_v_vstate_on(regs);
}
}
riscv: vector: allow kernel-mode Vector with preemption Add kernel_vstate to keep track of kernel-mode Vector registers when trap introduced context switch happens. Also, provide riscv_v_flags to let context save/restore routine track context status. Context tracking happens whenever the core starts its in-kernel Vector executions. An active (dirty) kernel task's V contexts will be saved to memory whenever a trap-introduced context switch happens. Or, when a softirq, which happens to nest on top of it, uses Vector. Context retoring happens when the execution transfer back to the original Kernel context where it first enable preempt_v. Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an option to disable preemptible kernel-mode Vector at build time. Users with constraint memory may want to disable this config as preemptible kernel-mode Vector needs extra space for tracking of per thread's kernel-mode V context. Or, users might as well want to disable it if all kernel-mode Vector code is time sensitive and cannot tolerate context switch overhead. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:29 +00:00
#ifdef CONFIG_RISCV_ISA_V_PREEMPTIVE
static inline bool riscv_preempt_v_dirty(struct task_struct *task)
{
return !!(task->thread.riscv_v_flags & RISCV_PREEMPT_V_DIRTY);
}
static inline bool riscv_preempt_v_restore(struct task_struct *task)
{
return !!(task->thread.riscv_v_flags & RISCV_PREEMPT_V_NEED_RESTORE);
}
static inline void riscv_preempt_v_clear_dirty(struct task_struct *task)
{
barrier();
task->thread.riscv_v_flags &= ~RISCV_PREEMPT_V_DIRTY;
}
static inline void riscv_preempt_v_set_restore(struct task_struct *task)
{
barrier();
task->thread.riscv_v_flags |= RISCV_PREEMPT_V_NEED_RESTORE;
}
static inline bool riscv_preempt_v_started(struct task_struct *task)
{
return !!(task->thread.riscv_v_flags & RISCV_PREEMPT_V);
}
#else /* !CONFIG_RISCV_ISA_V_PREEMPTIVE */
static inline bool riscv_preempt_v_dirty(struct task_struct *task) { return false; }
static inline bool riscv_preempt_v_restore(struct task_struct *task) { return false; }
static inline bool riscv_preempt_v_started(struct task_struct *task) { return false; }
#define riscv_preempt_v_clear_dirty(tsk) do {} while (0)
#define riscv_preempt_v_set_restore(tsk) do {} while (0)
#endif /* CONFIG_RISCV_ISA_V_PREEMPTIVE */
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
static inline void __switch_to_vector(struct task_struct *prev,
struct task_struct *next)
{
struct pt_regs *regs;
riscv: vector: allow kernel-mode Vector with preemption Add kernel_vstate to keep track of kernel-mode Vector registers when trap introduced context switch happens. Also, provide riscv_v_flags to let context save/restore routine track context status. Context tracking happens whenever the core starts its in-kernel Vector executions. An active (dirty) kernel task's V contexts will be saved to memory whenever a trap-introduced context switch happens. Or, when a softirq, which happens to nest on top of it, uses Vector. Context retoring happens when the execution transfer back to the original Kernel context where it first enable preempt_v. Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an option to disable preemptible kernel-mode Vector at build time. Users with constraint memory may want to disable this config as preemptible kernel-mode Vector needs extra space for tracking of per thread's kernel-mode V context. Or, users might as well want to disable it if all kernel-mode Vector code is time sensitive and cannot tolerate context switch overhead. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:29 +00:00
if (riscv_preempt_v_started(prev)) {
riscv: vector: Support calling schedule() for preemptible Vector Each function entry implies a call to ftrace infrastructure. And it may call into schedule in some cases. So, it is possible for preemptible kernel-mode Vector to implicitly call into schedule. Since all V-regs are caller-saved, it is possible to drop all V context when a thread voluntarily call schedule(). Besides, we currently don't pass argument through vector register, so we don't have to save/restore V-regs in ftrace trampoline. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20250407180838.42877-7-andybnac@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-04-08 02:08:31 +08:00
if (riscv_v_is_on()) {
WARN_ON(prev->thread.riscv_v_flags & RISCV_V_CTX_DEPTH_MASK);
riscv_v_disable();
prev->thread.riscv_v_flags |= RISCV_PREEMPT_V_IN_SCHEDULE;
}
riscv: vector: allow kernel-mode Vector with preemption Add kernel_vstate to keep track of kernel-mode Vector registers when trap introduced context switch happens. Also, provide riscv_v_flags to let context save/restore routine track context status. Context tracking happens whenever the core starts its in-kernel Vector executions. An active (dirty) kernel task's V contexts will be saved to memory whenever a trap-introduced context switch happens. Or, when a softirq, which happens to nest on top of it, uses Vector. Context retoring happens when the execution transfer back to the original Kernel context where it first enable preempt_v. Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an option to disable preemptible kernel-mode Vector at build time. Users with constraint memory may want to disable this config as preemptible kernel-mode Vector needs extra space for tracking of per thread's kernel-mode V context. Or, users might as well want to disable it if all kernel-mode Vector code is time sensitive and cannot tolerate context switch overhead. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:29 +00:00
if (riscv_preempt_v_dirty(prev)) {
__riscv_v_vstate_save(&prev->thread.kernel_vstate,
prev->thread.kernel_vstate.datap);
riscv_preempt_v_clear_dirty(prev);
}
} else {
regs = task_pt_regs(prev);
riscv_v_vstate_save(&prev->thread.vstate, regs);
}
riscv: vector: Support calling schedule() for preemptible Vector Each function entry implies a call to ftrace infrastructure. And it may call into schedule in some cases. So, it is possible for preemptible kernel-mode Vector to implicitly call into schedule. Since all V-regs are caller-saved, it is possible to drop all V context when a thread voluntarily call schedule(). Besides, we currently don't pass argument through vector register, so we don't have to save/restore V-regs in ftrace trampoline. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20250407180838.42877-7-andybnac@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-04-08 02:08:31 +08:00
if (riscv_preempt_v_started(next)) {
if (next->thread.riscv_v_flags & RISCV_PREEMPT_V_IN_SCHEDULE) {
next->thread.riscv_v_flags &= ~RISCV_PREEMPT_V_IN_SCHEDULE;
riscv_v_enable();
} else {
riscv_preempt_v_set_restore(next);
}
} else {
riscv: vector: allow kernel-mode Vector with preemption Add kernel_vstate to keep track of kernel-mode Vector registers when trap introduced context switch happens. Also, provide riscv_v_flags to let context save/restore routine track context status. Context tracking happens whenever the core starts its in-kernel Vector executions. An active (dirty) kernel task's V contexts will be saved to memory whenever a trap-introduced context switch happens. Or, when a softirq, which happens to nest on top of it, uses Vector. Context retoring happens when the execution transfer back to the original Kernel context where it first enable preempt_v. Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an option to disable preemptible kernel-mode Vector at build time. Users with constraint memory may want to disable this config as preemptible kernel-mode Vector needs extra space for tracking of per thread's kernel-mode V context. Or, users might as well want to disable it if all kernel-mode Vector code is time sensitive and cannot tolerate context switch overhead. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:29 +00:00
riscv_v_vstate_set_restore(next, task_pt_regs(next));
riscv: vector: Support calling schedule() for preemptible Vector Each function entry implies a call to ftrace infrastructure. And it may call into schedule in some cases. So, it is possible for preemptible kernel-mode Vector to implicitly call into schedule. Since all V-regs are caller-saved, it is possible to drop all V context when a thread voluntarily call schedule(). Besides, we currently don't pass argument through vector register, so we don't have to save/restore V-regs in ftrace trampoline. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20250407180838.42877-7-andybnac@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-04-08 02:08:31 +08:00
}
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
}
riscv: Add prctl controls for userspace vector management This patch add two riscv-specific prctls, to allow usespace control the use of vector unit: * PR_RISCV_V_SET_CONTROL: control the permission to use Vector at next, or all following execve for a thread. Turning off a thread's Vector live is not possible since libraries may have registered ifunc that may execute Vector instructions. * PR_RISCV_V_GET_CONTROL: get the same permission setting for the current thread, and the setting for following execve(s). Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Vincent Chen <vincent.chen@sifive.com> Link: https://lore.kernel.org/r/20230605110724.21391-22-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:18 +00:00
void riscv_v_vstate_ctrl_init(struct task_struct *tsk);
bool riscv_v_vstate_ctrl_user_allowed(void);
riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
#else /* ! CONFIG_RISCV_ISA_V */
riscv: Introduce riscv_v_vsize to record size of Vector context This patch is used to detect the size of CPU vector registers and use riscv_v_vsize to save the size of all the vector registers. It assumes all harts has the same capabilities in a SMP system. If a core detects VLENB that is different from the boot core, then it warns and turns off V support for user space. Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:05 +00:00
struct pt_regs;
static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; }
riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
static __always_inline bool has_vector(void) { return false; }
RISC-V: Detect unaligned vector accesses supported Run an unaligned vector access to test if the system supports vector unaligned access. Add the result to a new key in hwprobe. This is useful for usermode to know if vector misaligned accesses are supported and if they are faster or slower than equivalent byte accesses. Signed-off-by: Jesse Taube <jesse@rivosinc.com> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20241017-jesse_unaligned_vector-v10-4-5b33500160f8@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-17 12:00:21 -07:00
static __always_inline bool insn_is_vector(u32 insn_buf) { return false; }
riscv: vector: Support xtheadvector save/restore Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-13 18:21:15 -08:00
static __always_inline bool has_xtheadvector_no_alternatives(void) { return false; }
static __always_inline bool has_xtheadvector(void) { return false; }
riscv: Allocate user's vector context in the first-use trap Vector unit is disabled by default for all user processes. Thus, a process will take a trap (illegal instruction) into kernel at the first time when it uses Vector. Only after then, the kernel allocates V context and starts take care of the context for that user process. Suggested-by: Richard Henderson <richard.henderson@linaro.org> Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230605110724.21391-12-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:08 +00:00
static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return false; }
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; }
riscv: Add prctl controls for userspace vector management This patch add two riscv-specific prctls, to allow usespace control the use of vector unit: * PR_RISCV_V_SET_CONTROL: control the permission to use Vector at next, or all following execve for a thread. Turning off a thread's Vector live is not possible since libraries may have registered ifunc that may execute Vector instructions. * PR_RISCV_V_GET_CONTROL: get the same permission setting for the current thread, and the setting for following execve(s). Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Vincent Chen <vincent.chen@sifive.com> Link: https://lore.kernel.org/r/20230605110724.21391-22-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:18 +00:00
static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; }
riscv: Introduce riscv_v_vsize to record size of Vector context This patch is used to detect the size of CPU vector registers and use riscv_v_vsize to save the size of all the vector registers. It assumes all harts has the same capabilities in a SMP system. If a core detects VLENB that is different from the boot core, then it warns and turns off V support for user space. Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:05 +00:00
#define riscv_v_vsize (0)
riscv: Discard vector state on syscalls The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-29 16:22:28 +02:00
#define riscv_v_vstate_discard(regs) do {} while (0)
riscv: vector: do not pass task_struct into riscv_v_vstate_{save,restore}() riscv_v_vstate_{save,restore}() can operate only on the knowlege of struct __riscv_v_ext_state, and struct pt_regs. Let the caller decides which should be passed into the function. Meanwhile, the kernel-mode Vector is going to introduce another vstate, so this also makes functions potentially able to be reused. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-8-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:26 +00:00
#define riscv_v_vstate_save(vstate, regs) do {} while (0)
#define riscv_v_vstate_restore(vstate, regs) do {} while (0)
riscv: Add task switch support for vector This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Co-developed-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Ruinland Tsai <ruinland.tsai@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:07 +00:00
#define __switch_to_vector(__prev, __next) do {} while (0)
riscv: Introduce struct/helpers to save/restore per-task Vector state Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:07:06 +00:00
#define riscv_v_vstate_off(regs) do {} while (0)
#define riscv_v_vstate_on(regs) do {} while (0)
riscv: vector: use kmem_cache to manage vector context The allocation size of thread.vstate.datap is always riscv_v_vsize. So it is possbile to use kmem_cache_* to manage the allocation. This gives users more information regarding allocation of vector context via /proc/slabinfo. And it potentially reduces the latency of the first-use trap because of the allocation caches. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:28 +00:00
#define riscv_v_thread_free(tsk) do {} while (0)
#define riscv_v_setup_ctx_cache() do {} while (0)
riscv: vector: allow kernel-mode Vector with preemption Add kernel_vstate to keep track of kernel-mode Vector registers when trap introduced context switch happens. Also, provide riscv_v_flags to let context save/restore routine track context status. Context tracking happens whenever the core starts its in-kernel Vector executions. An active (dirty) kernel task's V contexts will be saved to memory whenever a trap-introduced context switch happens. Or, when a softirq, which happens to nest on top of it, uses Vector. Context retoring happens when the execution transfer back to the original Kernel context where it first enable preempt_v. Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an option to disable preemptible kernel-mode Vector at build time. Users with constraint memory may want to disable this config as preemptible kernel-mode Vector needs extra space for tracking of per thread's kernel-mode V context. Or, users might as well want to disable it if all kernel-mode Vector code is time sensitive and cannot tolerate context switch overhead. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-15 05:59:29 +00:00
#define riscv_v_thread_alloc(tsk) do {} while (0)
riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
#endif /* CONFIG_RISCV_ISA_V */
RISC-V: add helper function to read the vector VLEN VLEN describes the length of each vector register and some instructions need specific minimal VLENs to work correctly. The vector code already includes a variable riscv_v_vsize that contains the value of "32 vector registers with vlenb length" that gets filled during boot. vlenb is the value contained in the CSR_VLENB register and the value represents "VLEN / 8". So add riscv_vector_vlen() to return the actual VLEN value for in-kernel users when they need to check the available VLEN. Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jerry Shih <jerry.shih@sifive.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20240122002024.27477-2-ebiggers@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-21 16:19:12 -08:00
/*
* Return the implementation's vlen value.
*
* riscv_v_vsize contains the value of "32 vector registers with vlenb length"
* so rebuild the vlen value in bits from it.
*/
static inline int riscv_vector_vlen(void)
{
return riscv_v_vsize / 32 * 8;
}
riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-05 11:06:59 +00:00
#endif /* ! __ASM_RISCV_VECTOR_H */
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