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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 97 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-29 07:18:00 -07:00
/* SPDX-License-Identifier: GPL-2.0-only */
RISC-V: Atomic and Locking Code This contains all the code that directly interfaces with the RISC-V memory model. While this code corforms to the current RISC-V ISA specifications (user 2.2 and priv 1.10), the memory model is somewhat underspecified in those documents. There is a working group that hopes to produce a formal memory model by the end of the year, but my understanding is that the basic definitions we're relying on here won't change significantly. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:02:19 -07:00
/*
* Copyright (C) 2015 Regents of the University of California
*/
#ifndef _ASM_RISCV_CACHEFLUSH_H
#define _ASM_RISCV_CACHEFLUSH_H
riscv: fix build break after macro-to-function conversion in generic cacheflush.h Commit c296d4dc13ae ("asm-generic: fix a compilation warning") converted the various flush_*cache_* macros in asm-generic/cacheflush.h to static inline functions. This breaks RISC-V builds, since RISC-V's cacheflush.h includes the generic cacheflush.h and then undefines the macros to be overridden. Fix by copying the subset of the no-op functions that are reused from the generic cacheflush.h into the RISC-V cacheflush.h, and dropping the include of the generic cacheflush.h. Fixes: c296d4dc13ae ("asm-generic: fix a compilation warning") Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Cc: Qian Cai <cai@lca.pw> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-17 13:41:51 -07:00
#include <linux/mm.h>
RISC-V: Atomic and Locking Code This contains all the code that directly interfaces with the RISC-V memory model. While this code corforms to the current RISC-V ISA specifications (user 2.2 and priv 1.10), the memory model is somewhat underspecified in those documents. There is a working group that hopes to produce a formal memory model by the end of the year, but my understanding is that the basic definitions we're relying on here won't change significantly. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:02:19 -07:00
static inline void local_flush_icache_all(void)
{
asm volatile ("fence.i" ::: "memory");
}
riscv: Fix early ftrace nop patching Commit c97bf629963e ("riscv: Fix text patching when IPI are used") converted ftrace_make_nop() to use patch_insn_write() which does not emit any icache flush relying entirely on __ftrace_modify_code() to do that. But we missed that ftrace_make_nop() was called very early directly when converting mcount calls into nops (actually on riscv it converts 2B nops emitted by the compiler into 4B nops). This caused crashes on multiple HW as reported by Conor and Björn since the booting core could have half-patched instructions in its icache which would trigger an illegal instruction trap: fix this by emitting a local flush icache when early patching nops. Fixes: c97bf629963e ("riscv: Fix text patching when IPI are used") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reported-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20240523115134.70380-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-23 13:51:34 +02:00
static inline void local_flush_icache_range(unsigned long start,
unsigned long end)
{
local_flush_icache_all();
}
RISC-V: Flush I$ when making a dirty page executable The RISC-V ISA allows for instruction caches that are not coherent WRT stores, even on a single hart. As a result, we need to explicitly flush the instruction cache whenever marking a dirty page as executable in order to preserve the correct system behavior. Local instruction caches aren't that scary (our implementations actually flush the cache, but RISC-V is defined to allow higher-performance implementations to exist), but RISC-V defines no way to perform an instruction cache shootdown. When explicitly asked to do so we can shoot down remote instruction caches via an IPI, but this is a bit on the slow side. Instead of requiring an IPI to all harts whenever marking a page as executable, we simply flush the currently running harts. In order to maintain correct behavior, we additionally mark every other hart as needing a deferred instruction cache which will be taken before anything runs on it. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:30:32 -07:00
#define PG_dcache_clean PG_arch_1
riscv: implement the new page table range API Add set_ptes(), update_mmu_cache_range() and flush_dcache_folio(). Change the PG_dcache_clean flag from being per-page to per-folio. Link: https://lkml.kernel.org/r/20230802151406.3735276-23-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-02 16:13:50 +01:00
static inline void flush_dcache_folio(struct folio *folio)
RISC-V: Flush I$ when making a dirty page executable The RISC-V ISA allows for instruction caches that are not coherent WRT stores, even on a single hart. As a result, we need to explicitly flush the instruction cache whenever marking a dirty page as executable in order to preserve the correct system behavior. Local instruction caches aren't that scary (our implementations actually flush the cache, but RISC-V is defined to allow higher-performance implementations to exist), but RISC-V defines no way to perform an instruction cache shootdown. When explicitly asked to do so we can shoot down remote instruction caches via an IPI, but this is a bit on the slow side. Instead of requiring an IPI to all harts whenever marking a page as executable, we simply flush the currently running harts. In order to maintain correct behavior, we additionally mark every other hart as needing a deferred instruction cache which will be taken before anything runs on it. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:30:32 -07:00
{
riscv: implement the new page table range API Add set_ptes(), update_mmu_cache_range() and flush_dcache_folio(). Change the PG_dcache_clean flag from being per-page to per-folio. Link: https://lkml.kernel.org/r/20230802151406.3735276-23-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-02 16:13:50 +01:00
if (test_bit(PG_dcache_clean, &folio->flags))
clear_bit(PG_dcache_clean, &folio->flags);
RISC-V: Flush I$ when making a dirty page executable The RISC-V ISA allows for instruction caches that are not coherent WRT stores, even on a single hart. As a result, we need to explicitly flush the instruction cache whenever marking a dirty page as executable in order to preserve the correct system behavior. Local instruction caches aren't that scary (our implementations actually flush the cache, but RISC-V is defined to allow higher-performance implementations to exist), but RISC-V defines no way to perform an instruction cache shootdown. When explicitly asked to do so we can shoot down remote instruction caches via an IPI, but this is a bit on the slow side. Instead of requiring an IPI to all harts whenever marking a page as executable, we simply flush the currently running harts. In order to maintain correct behavior, we additionally mark every other hart as needing a deferred instruction cache which will be taken before anything runs on it. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:30:32 -07:00
}
riscv: implement the new page table range API Add set_ptes(), update_mmu_cache_range() and flush_dcache_folio(). Change the PG_dcache_clean flag from being per-page to per-folio. Link: https://lkml.kernel.org/r/20230802151406.3735276-23-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-02 16:13:50 +01:00
#define flush_dcache_folio flush_dcache_folio
riscv: use asm-generic/cacheflush.h RISC-V needs almost no cache flushing routines of its own. Rely on asm-generic/cacheflush.h for the defaults. Also remove the pointless __KERNEL__ ifdef while we're at it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Link: http://lkml.kernel.org/r/20200515143646.3857579-18-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-07 21:42:15 -07:00
#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
RISC-V: Flush I$ when making a dirty page executable The RISC-V ISA allows for instruction caches that are not coherent WRT stores, even on a single hart. As a result, we need to explicitly flush the instruction cache whenever marking a dirty page as executable in order to preserve the correct system behavior. Local instruction caches aren't that scary (our implementations actually flush the cache, but RISC-V is defined to allow higher-performance implementations to exist), but RISC-V defines no way to perform an instruction cache shootdown. When explicitly asked to do so we can shoot down remote instruction caches via an IPI, but this is a bit on the slow side. Instead of requiring an IPI to all harts whenever marking a page as executable, we simply flush the currently running harts. In order to maintain correct behavior, we additionally mark every other hart as needing a deferred instruction cache which will be taken before anything runs on it. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:30:32 -07:00
riscv: implement the new page table range API Add set_ptes(), update_mmu_cache_range() and flush_dcache_folio(). Change the PG_dcache_clean flag from being per-page to per-folio. Link: https://lkml.kernel.org/r/20230802151406.3735276-23-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-02 16:13:50 +01:00
static inline void flush_dcache_page(struct page *page)
{
flush_dcache_folio(page_folio(page));
}
RISC-V: only flush icache when it has VM_EXEC set As I-Cache flush on current RISC-V needs to send IPIs to every CPU cores in the system is very costly, limiting flush_icache_mm to be called only when vma->vm_flags has VM_EXEC can help minimize the frequency of these operations. It improves performance and reduces disturbances when copy_from_user_page is needed such as profiling with perf. For I-D coherence concerns, it will not fail if such a page adds VM_EXEC flags in the future since we have checked it in the __set_pte_at function. Signed-off-by: Yangyu Chen <cyy@cyyself.name> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/tencent_6D851035F6F2FD0B5A69FB391AE39AC6300A@qq.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-10 02:48:59 +08:00
#define flush_icache_user_page(vma, pg, addr, len) \
do { \
if (vma->vm_flags & VM_EXEC) \
flush_icache_mm(vma->vm_mm, 0); \
} while (0)
RISC-V: Flush I$ when making a dirty page executable The RISC-V ISA allows for instruction caches that are not coherent WRT stores, even on a single hart. As a result, we need to explicitly flush the instruction cache whenever marking a dirty page as executable in order to preserve the correct system behavior. Local instruction caches aren't that scary (our implementations actually flush the cache, but RISC-V is defined to allow higher-performance implementations to exist), but RISC-V defines no way to perform an instruction cache shootdown. When explicitly asked to do so we can shoot down remote instruction caches via an IPI, but this is a bit on the slow side. Instead of requiring an IPI to all harts whenever marking a page as executable, we simply flush the currently running harts. In order to maintain correct behavior, we additionally mark every other hart as needing a deferred instruction cache which will be taken before anything runs on it. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:30:32 -07:00
riscv: Implement flush_cache_vmap() The RISC-V kernel needs a sfence.vma after a page table modification: we used to rely on the vmalloc fault handling to emit an sfence.vma, but commit 7d3332be011e ("riscv: mm: Pre-allocate PGD entries for vmalloc/modules area") got rid of this path for 64-bit kernels, so now we need to explicitly emit a sfence.vma in flush_cache_vmap(). Note that we don't need to implement flush_cache_vunmap() as the generic code should emit a flush tlb after unmapping a vmalloc region. Fixes: 7d3332be011e ("riscv: mm: Pre-allocate PGD entries for vmalloc/modules area") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230725132246.817726-1-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25 15:22:46 +02:00
#ifdef CONFIG_64BIT
riscv: Stop emitting preventive sfence.vma for new vmalloc mappings In 6.5, we removed the vmalloc fault path because that can't work (see [1] [2]). Then in order to make sure that new page table entries were seen by the page table walker, we had to preventively emit a sfence.vma on all harts [3] but this solution is very costly since it relies on IPI. And even there, we could end up in a loop of vmalloc faults if a vmalloc allocation is done in the IPI path (for example if it is traced, see [4]), which could result in a kernel stack overflow. Those preventive sfence.vma needed to be emitted because: - if the uarch caches invalid entries, the new mapping may not be observed by the page table walker and an invalidation may be needed. - if the uarch does not cache invalid entries, a reordered access could "miss" the new mapping and traps: in that case, we would actually only need to retry the access, no sfence.vma is required. So this patch removes those preventive sfence.vma and actually handles the possible (and unlikely) exceptions. And since the kernel stacks mappings lie in the vmalloc area, this handling must be done very early when the trap is taken, at the very beginning of handle_exception: this also rules out the vmalloc allocations in the fault path. Link: https://lore.kernel.org/linux-riscv/20230531093817.665799-1-bjorn@kernel.org/ [1] Link: https://lore.kernel.org/linux-riscv/20230801090927.2018653-1-dylan@andestech.com [2] Link: https://lore.kernel.org/linux-riscv/20230725132246.817726-1-alexghiti@rivosinc.com/ [3] Link: https://lore.kernel.org/lkml/20200508144043.13893-1-joro@8bytes.org/ [4] Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://lore.kernel.org/r/20240717060125.139416-4-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-17 08:01:24 +02:00
extern u64 new_vmalloc[NR_CPUS / sizeof(u64) + 1];
extern char _end[];
#define flush_cache_vmap flush_cache_vmap
static inline void flush_cache_vmap(unsigned long start, unsigned long end)
{
if (is_vmalloc_or_module_addr((void *)start)) {
int i;
/*
* We don't care if concurrently a cpu resets this value since
* the only place this can happen is in handle_exception() where
* an sfence.vma is emitted.
*/
for (i = 0; i < ARRAY_SIZE(new_vmalloc); ++i)
new_vmalloc[i] = -1ULL;
}
}
mm: Introduce flush_cache_vmap_early() The pcpu setup when using the page allocator sets up a new vmalloc mapping very early in the boot process, so early that it cannot use the flush_cache_vmap() function which may depend on structures not yet initialized (for example in riscv, we currently send an IPI to flush other cpus TLB). But on some architectures, we must call flush_cache_vmap(): for example, in riscv, some uarchs can cache invalid TLB entries so we need to flush the new established mapping to avoid taking an exception. So fix this by introducing a new function flush_cache_vmap_early() which is called right after setting the new page table entry and before accessing this new mapping. This new function implements a local flush tlb on riscv and is no-op for other architectures (same as today). Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dennis Zhou <dennis@kernel.org>
2023-12-12 22:34:56 +01:00
#define flush_cache_vmap_early(start, end) local_flush_tlb_kernel_range(start, end)
riscv: Implement flush_cache_vmap() The RISC-V kernel needs a sfence.vma after a page table modification: we used to rely on the vmalloc fault handling to emit an sfence.vma, but commit 7d3332be011e ("riscv: mm: Pre-allocate PGD entries for vmalloc/modules area") got rid of this path for 64-bit kernels, so now we need to explicitly emit a sfence.vma in flush_cache_vmap(). Note that we don't need to implement flush_cache_vunmap() as the generic code should emit a flush tlb after unmapping a vmalloc region. Fixes: 7d3332be011e ("riscv: mm: Pre-allocate PGD entries for vmalloc/modules area") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230725132246.817726-1-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25 15:22:46 +02:00
#endif
RISC-V: Atomic and Locking Code This contains all the code that directly interfaces with the RISC-V memory model. While this code corforms to the current RISC-V ISA specifications (user 2.2 and priv 1.10), the memory model is somewhat underspecified in those documents. There is a working group that hopes to produce a formal memory model by the end of the year, but my understanding is that the basic definitions we're relying on here won't change significantly. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:02:19 -07:00
#ifndef CONFIG_SMP
RISC-V: Flush I$ when making a dirty page executable The RISC-V ISA allows for instruction caches that are not coherent WRT stores, even on a single hart. As a result, we need to explicitly flush the instruction cache whenever marking a dirty page as executable in order to preserve the correct system behavior. Local instruction caches aren't that scary (our implementations actually flush the cache, but RISC-V is defined to allow higher-performance implementations to exist), but RISC-V defines no way to perform an instruction cache shootdown. When explicitly asked to do so we can shoot down remote instruction caches via an IPI, but this is a bit on the slow side. Instead of requiring an IPI to all harts whenever marking a page as executable, we simply flush the currently running harts. In order to maintain correct behavior, we additionally mark every other hart as needing a deferred instruction cache which will be taken before anything runs on it. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:30:32 -07:00
#define flush_icache_all() local_flush_icache_all()
#define flush_icache_mm(mm, local) flush_icache_all()
RISC-V: Atomic and Locking Code This contains all the code that directly interfaces with the RISC-V memory model. While this code corforms to the current RISC-V ISA specifications (user 2.2 and priv 1.10), the memory model is somewhat underspecified in those documents. There is a working group that hopes to produce a formal memory model by the end of the year, but my understanding is that the basic definitions we're relying on here won't change significantly. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:02:19 -07:00
#else /* CONFIG_SMP */
riscv: move flush_icache_{all,mm} to cacheflush.c Currently, flush_icache_all is macro-expanded into a SBI call, yet no asm/sbi.h is included in asm/cacheflush.h. This could be moved to mm/cacheflush.c instead (SBI call will dominate performance-wise and there is no worry to not have it inlined. Currently, flush_icache_mm stays in kernel/smp.c, which looks like a hack to prevent it from being compiled when CONFIG_SMP=n. It should also be in mm/cacheflush.c. Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-27 00:41:25 +00:00
void flush_icache_all(void);
RISC-V: Flush I$ when making a dirty page executable The RISC-V ISA allows for instruction caches that are not coherent WRT stores, even on a single hart. As a result, we need to explicitly flush the instruction cache whenever marking a dirty page as executable in order to preserve the correct system behavior. Local instruction caches aren't that scary (our implementations actually flush the cache, but RISC-V is defined to allow higher-performance implementations to exist), but RISC-V defines no way to perform an instruction cache shootdown. When explicitly asked to do so we can shoot down remote instruction caches via an IPI, but this is a bit on the slow side. Instead of requiring an IPI to all harts whenever marking a page as executable, we simply flush the currently running harts. In order to maintain correct behavior, we additionally mark every other hart as needing a deferred instruction cache which will be taken before anything runs on it. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:30:32 -07:00
void flush_icache_mm(struct mm_struct *mm, bool local);
RISC-V: Atomic and Locking Code This contains all the code that directly interfaces with the RISC-V memory model. While this code corforms to the current RISC-V ISA specifications (user 2.2 and priv 1.10), the memory model is somewhat underspecified in those documents. There is a working group that hopes to produce a formal memory model by the end of the year, but my understanding is that the basic definitions we're relying on here won't change significantly. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:02:19 -07:00
#endif /* CONFIG_SMP */
riscv: Replace function-like macro by static inline function The flush_icache_range() function is implemented as a "function-like macro with unused parameters", which can result in "unused variables" warnings. Replace the macro with a static inline function, as advised by Documentation/process/coding-style.rst. Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable") Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20250419111402.1660267-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-04-19 13:13:59 +02:00
/*
* RISC-V doesn't have an instruction to flush parts of the instruction cache,
* so instead we just flush the whole thing.
*/
#define flush_icache_range flush_icache_range
static inline void flush_icache_range(unsigned long start, unsigned long end)
{
flush_icache_all();
}
RISC-V: Clean up the Zicbom block size probing This fixes two issues: I truncated the warning's hart ID when porting to the 64-bit hart ID code, and the original code's warning handling could fire on an uninitialized hart ID. The biggest change here is that riscv_cbom_block_size is no longer initialized, as IMO the default isn't sane: there's nothing in the ISA that mandates any specific cache block size, so falling back to one will just silently produce the wrong answer on some systems. This also changes the probing order so the cache block size is known before enabling Zicbom support. CC: stable@vger.kernel.org CC: Andrew Jones <ajones@ventanamicro.com> CC: Heiko Stuebner <heiko@sntech.de> CC: Atish Patra <atishp@rivosinc.com> Fixes: 3aefb2ee5bdd ("riscv: implement Zicbom-based CMO instructions + the t-head variant") Fixes: 1631ba1259d6 ("riscv: Add support for non-coherent devices using zicbom extension") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> [Conor: fixed the redefinition errors] Tested-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220912224800.998121-1-mail@conchuod.ie Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-09-12 23:48:01 +01:00
extern unsigned int riscv_cbom_block_size;
RISC-V: Add Zicboz detection and block size parsing Parse "riscv,cboz-block-size" from the DT by piggybacking on Zicbom's riscv_init_cbom_blocksize(). Additionally check the DT for the presence of the "zicboz" extension and, when it's present, validate the parsed cboz block size as we do Zicbom's cbom block size with riscv_isa_extension_check(). Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230224162631.405473-5-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-24 17:26:27 +01:00
extern unsigned int riscv_cboz_block_size;
riscv: Add support for Zicbop Zicbop introduces cache blocks prefetching instructions, add the necessary support for the kernel to use it in the coming commits. Co-developed-by: Guo Ren <guoren@kernel.org> Signed-off-by: Guo Ren <guoren@kernel.org> Tested-by: Andrea Parri <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20250421142441.395849-3-alexghiti@rivosinc.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-04-21 16:24:39 +02:00
extern unsigned int riscv_cbop_block_size;
RISC-V: Add Zicboz detection and block size parsing Parse "riscv,cboz-block-size" from the DT by piggybacking on Zicbom's riscv_init_cbom_blocksize(). Additionally check the DT for the presence of the "zicboz" extension and, when it's present, validate the parsed cboz block size as we do Zicbom's cbom block size with riscv_isa_extension_check(). Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230224162631.405473-5-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-24 17:26:27 +01:00
void riscv_init_cbo_blocksizes(void);
riscv: Add support for non-coherent devices using zicbom extension The Zicbom ISA-extension was ratified in november 2021 and introduces instructions for dcache invalidate, clean and flush operations. Implement cache management operations for non-coherent devices based on them. Of course not all cores will support this, so implement an alternative-based mechanism that replaces empty instructions with ones done around Zicbom instructions. As discussed in previous versions, assume the platform being coherent by default so that non-coherent devices need to get marked accordingly by firmware. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220706231536.2041855-4-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-07 01:15:35 +02:00
#ifdef CONFIG_RISCV_DMA_NONCOHERENT
void riscv_noncoherent_supported(void);
riscv: allow kmalloc() caches aligned to the smallest value Currently, riscv defines ARCH_DMA_MINALIGN as L1_CACHE_BYTES, I.E 64Bytes, if CONFIG_RISCV_DMA_NONCOHERENT=y. To support unified kernel Image, usually we have to enable CONFIG_RISCV_DMA_NONCOHERENT, thus it brings some bad effects to coherent platforms: Firstly, it wastes memory, kmalloc-96, kmalloc-32, kmalloc-16 and kmalloc-8 slab caches don't exist any more, they are replaced with either kmalloc-128 or kmalloc-64. Secondly, larger than necessary kmalloc aligned allocations results in unnecessary cache/TLB pressure. This issue also exists on arm64 platforms. From last year, Catalin tried to solve this issue by decoupling ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN, limiting kmalloc() minimum alignment to dma_get_cache_alignment() and replacing ARCH_KMALLOC_MINALIGN usage in various drivers with ARCH_DMA_MINALIGN etc.[1] One fact we can make use of for riscv: if the CPU doesn't support ZICBOM or T-HEAD CMO, we know the platform is coherent. Based on Catalin's work and above fact, we can easily solve the kmalloc align issue for riscv: we can override dma_get_cache_alignment(), then let it return ARCH_DMA_MINALIGN at the beginning and return 1 once we know the underlying HW neither supports ZICBOM nor supports T-HEAD CMO. So what about if the CPU supports ZICBOM or T-HEAD CMO, but all the devices are dma coherent? Well, we use ARCH_DMA_MINALIGN as the kmalloc minimum alignment, nothing changed in this case. This case can be improved in the future. After this patch, a simple test of booting to a small buildroot rootfs on qemu shows: kmalloc-96 5041 5041 96 ... kmalloc-64 9606 9606 64 ... kmalloc-32 5128 5128 32 ... kmalloc-16 7682 7682 16 ... kmalloc-8 10246 10246 8 ... So we save about 1268KB memory. The saving will be much larger in normal OS env on real HW platforms. Link: https://lore.kernel.org/linux-arm-kernel/20230524171904.3967031-1-catalin.marinas@arm.com/ [1] Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230718152214.2907-2-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-18 23:22:13 +08:00
void __init riscv_set_dma_cache_alignment(void);
riscv: drop some idefs from CMO initialization Wrapping things in #ifdefs makes the code harder to read while we also have IS_ENABLED() macros to do this in regular code and the extension detection is not _that_ runtime critical. So define a stub for riscv_noncoherent_supported() in the non-CONFIG_RISCV_DMA_NONCOHERENT case and move the code to us IS_ENABLED. Suggested-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20220905111027.2463297-3-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-09-05 13:10:24 +02:00
#else
static inline void riscv_noncoherent_supported(void) {}
riscv: allow kmalloc() caches aligned to the smallest value Currently, riscv defines ARCH_DMA_MINALIGN as L1_CACHE_BYTES, I.E 64Bytes, if CONFIG_RISCV_DMA_NONCOHERENT=y. To support unified kernel Image, usually we have to enable CONFIG_RISCV_DMA_NONCOHERENT, thus it brings some bad effects to coherent platforms: Firstly, it wastes memory, kmalloc-96, kmalloc-32, kmalloc-16 and kmalloc-8 slab caches don't exist any more, they are replaced with either kmalloc-128 or kmalloc-64. Secondly, larger than necessary kmalloc aligned allocations results in unnecessary cache/TLB pressure. This issue also exists on arm64 platforms. From last year, Catalin tried to solve this issue by decoupling ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN, limiting kmalloc() minimum alignment to dma_get_cache_alignment() and replacing ARCH_KMALLOC_MINALIGN usage in various drivers with ARCH_DMA_MINALIGN etc.[1] One fact we can make use of for riscv: if the CPU doesn't support ZICBOM or T-HEAD CMO, we know the platform is coherent. Based on Catalin's work and above fact, we can easily solve the kmalloc align issue for riscv: we can override dma_get_cache_alignment(), then let it return ARCH_DMA_MINALIGN at the beginning and return 1 once we know the underlying HW neither supports ZICBOM nor supports T-HEAD CMO. So what about if the CPU supports ZICBOM or T-HEAD CMO, but all the devices are dma coherent? Well, we use ARCH_DMA_MINALIGN as the kmalloc minimum alignment, nothing changed in this case. This case can be improved in the future. After this patch, a simple test of booting to a small buildroot rootfs on qemu shows: kmalloc-96 5041 5041 96 ... kmalloc-64 9606 9606 64 ... kmalloc-32 5128 5128 32 ... kmalloc-16 7682 7682 16 ... kmalloc-8 10246 10246 8 ... So we save about 1268KB memory. The saving will be much larger in normal OS env on real HW platforms. Link: https://lore.kernel.org/linux-arm-kernel/20230524171904.3967031-1-catalin.marinas@arm.com/ [1] Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230718152214.2907-2-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-18 23:22:13 +08:00
static inline void riscv_set_dma_cache_alignment(void) {}
riscv: Add support for non-coherent devices using zicbom extension The Zicbom ISA-extension was ratified in november 2021 and introduces instructions for dcache invalidate, clean and flush operations. Implement cache management operations for non-coherent devices based on them. Of course not all cores will support this, so implement an alternative-based mechanism that replaces empty instructions with ones done around Zicbom instructions. As discussed in previous versions, assume the platform being coherent by default so that non-coherent devices need to get marked accordingly by firmware. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220706231536.2041855-4-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-07 01:15:35 +02:00
#endif
RISC-V: Allow userspace to flush the instruction cache Despite RISC-V having a direct 'fence.i' instruction available to userspace (which we can't trap!), that's not actually viable when running on Linux because the kernel might schedule a process on another hart. There is no way for userspace to handle this without invoking the kernel (as it doesn't know the thread->hart mappings), so we've defined a RISC-V specific system call to flush the instruction cache. This patch adds both a system call and a VDSO entry. If possible, we'd like to avoid having the system call be considered part of the user-facing ABI and instead restrict that to the VDSO entry -- both just in general to avoid having additional user-visible ABI to maintain, and because we'd prefer that users just call the VDSO entry because there might be a better way to do this in the future (ie, one that doesn't require entering the kernel). Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:32:16 -07:00
/*
* Bits in sys_riscv_flush_icache()'s flags argument.
*/
#define SYS_RISCV_FLUSH_ICACHE_LOCAL 1UL
#define SYS_RISCV_FLUSH_ICACHE_ALL (SYS_RISCV_FLUSH_ICACHE_LOCAL)
riscv: use asm-generic/cacheflush.h RISC-V needs almost no cache flushing routines of its own. Rely on asm-generic/cacheflush.h for the defaults. Also remove the pointless __KERNEL__ ifdef while we're at it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Link: http://lkml.kernel.org/r/20200515143646.3857579-18-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-07 21:42:15 -07:00
#include <asm-generic/cacheflush.h>
RISC-V: Atomic and Locking Code This contains all the code that directly interfaces with the RISC-V memory model. While this code corforms to the current RISC-V ISA specifications (user 2.2 and priv 1.10), the memory model is somewhat underspecified in those documents. There is a working group that hopes to produce a formal memory model by the end of the year, but my understanding is that the basic definitions we're relying on here won't change significantly. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:02:19 -07:00
#endif /* _ASM_RISCV_CACHEFLUSH_H */
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