mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-08-05 16:54:27 +00:00
cdcb6fa14e
No point in being in global headers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211015011539.628516182@linutronix.de
143 lines
3.9 KiB
C
143 lines
3.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Copyright (C) 1994 Linus Torvalds
|
|
*
|
|
* Pentium III FXSR, SSE support
|
|
* General FPU state handling cleanups
|
|
* Gareth Hughes <gareth@valinux.com>, May 2000
|
|
* x86-64 work by Andi Kleen 2002
|
|
*/
|
|
|
|
#ifndef _ASM_X86_FPU_INTERNAL_H
|
|
#define _ASM_X86_FPU_INTERNAL_H
|
|
|
|
#include <linux/compat.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <asm/user.h>
|
|
#include <asm/fpu/api.h>
|
|
#include <asm/fpu/xstate.h>
|
|
#include <asm/fpu/xcr.h>
|
|
#include <asm/cpufeature.h>
|
|
#include <asm/trace/fpu.h>
|
|
|
|
/*
|
|
* High level FPU state handling functions:
|
|
*/
|
|
extern bool fpu__restore_sig(void __user *buf, int ia32_frame);
|
|
extern void fpu__clear_user_states(struct fpu *fpu);
|
|
extern int fpu__exception_code(struct fpu *fpu, int trap_nr);
|
|
|
|
extern void fpu_sync_fpstate(struct fpu *fpu);
|
|
|
|
/*
|
|
* Boot time FPU initialization functions:
|
|
*/
|
|
extern void fpu__init_cpu(void);
|
|
extern void fpu__init_system_xstate(void);
|
|
extern void fpu__init_cpu_xstate(void);
|
|
extern void fpu__init_system(struct cpuinfo_x86 *c);
|
|
extern void fpu__init_check_bugs(void);
|
|
extern void fpu__resume_cpu(void);
|
|
|
|
extern union fpregs_state init_fpstate;
|
|
extern void fpstate_init_user(union fpregs_state *state);
|
|
|
|
#ifdef CONFIG_MATH_EMULATION
|
|
extern void fpstate_init_soft(struct swregs_state *soft);
|
|
#else
|
|
static inline void fpstate_init_soft(struct swregs_state *soft) {}
|
|
#endif
|
|
|
|
extern void restore_fpregs_from_fpstate(union fpregs_state *fpstate, u64 mask);
|
|
|
|
extern bool copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size);
|
|
|
|
/*
|
|
* FPU context switch related helper methods:
|
|
*/
|
|
|
|
DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);
|
|
|
|
/*
|
|
* The in-register FPU state for an FPU context on a CPU is assumed to be
|
|
* valid if the fpu->last_cpu matches the CPU, and the fpu_fpregs_owner_ctx
|
|
* matches the FPU.
|
|
*
|
|
* If the FPU register state is valid, the kernel can skip restoring the
|
|
* FPU state from memory.
|
|
*
|
|
* Any code that clobbers the FPU registers or updates the in-memory
|
|
* FPU state for a task MUST let the rest of the kernel know that the
|
|
* FPU registers are no longer valid for this task.
|
|
*
|
|
* Either one of these invalidation functions is enough. Invalidate
|
|
* a resource you control: CPU if using the CPU for something else
|
|
* (with preemption disabled), FPU for the current task, or a task that
|
|
* is prevented from running by the current task.
|
|
*/
|
|
static inline void __cpu_invalidate_fpregs_state(void)
|
|
{
|
|
__this_cpu_write(fpu_fpregs_owner_ctx, NULL);
|
|
}
|
|
|
|
static inline void __fpu_invalidate_fpregs_state(struct fpu *fpu)
|
|
{
|
|
fpu->last_cpu = -1;
|
|
}
|
|
|
|
static inline int fpregs_state_valid(struct fpu *fpu, unsigned int cpu)
|
|
{
|
|
return fpu == this_cpu_read(fpu_fpregs_owner_ctx) && cpu == fpu->last_cpu;
|
|
}
|
|
|
|
/*
|
|
* These generally need preemption protection to work,
|
|
* do try to avoid using these on their own:
|
|
*/
|
|
static inline void fpregs_deactivate(struct fpu *fpu)
|
|
{
|
|
this_cpu_write(fpu_fpregs_owner_ctx, NULL);
|
|
trace_x86_fpu_regs_deactivated(fpu);
|
|
}
|
|
|
|
static inline void fpregs_activate(struct fpu *fpu)
|
|
{
|
|
this_cpu_write(fpu_fpregs_owner_ctx, fpu);
|
|
trace_x86_fpu_regs_activated(fpu);
|
|
}
|
|
|
|
/* Internal helper for switch_fpu_return() and signal frame setup */
|
|
static inline void fpregs_restore_userregs(void)
|
|
{
|
|
struct fpu *fpu = ¤t->thread.fpu;
|
|
int cpu = smp_processor_id();
|
|
|
|
if (WARN_ON_ONCE(current->flags & PF_KTHREAD))
|
|
return;
|
|
|
|
if (!fpregs_state_valid(fpu, cpu)) {
|
|
u64 mask;
|
|
|
|
/*
|
|
* This restores _all_ xstate which has not been
|
|
* established yet.
|
|
*
|
|
* If PKRU is enabled, then the PKRU value is already
|
|
* correct because it was either set in switch_to() or in
|
|
* flush_thread(). So it is excluded because it might be
|
|
* not up to date in current->thread.fpu.xsave state.
|
|
*/
|
|
mask = xfeatures_mask_restore_user() |
|
|
xfeatures_mask_supervisor();
|
|
restore_fpregs_from_fpstate(&fpu->state, mask);
|
|
|
|
fpregs_activate(fpu);
|
|
fpu->last_cpu = cpu;
|
|
}
|
|
clear_thread_flag(TIF_NEED_FPU_LOAD);
|
|
}
|
|
|
|
#endif /* _ASM_X86_FPU_INTERNAL_H */
|