diff options
| author | Ingo Molnar <[email protected]> | 2017-09-23 15:00:02 +0200 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2017-09-24 13:04:34 +0200 |
| commit | 6cf4edbe0526db311a28734609da888fdfcb3604 (patch) | |
| tree | ae414faeb5a0e91376697a3b54719cc74374dc43 | |
| parent | f1c8cd0176078c7bcafdc89cac447cab672a0b5e (diff) | |
x86/fpu: Decouple fpregs_activate()/fpregs_deactivate() from fpu->fpregs_active
The fpregs_activate()/fpregs_deactivate() are currently called in such a pattern:
if (!fpu->fpregs_active)
fpregs_activate(fpu);
...
if (fpu->fpregs_active)
fpregs_deactivate(fpu);
But note that it's actually safe to call them without checking the flag first.
This further decouples the fpu->fpregs_active flag from actual FPU logic.
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Yu-cheng Yu <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | arch/x86/include/asm/fpu/internal.h | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 3 |
2 files changed, 2 insertions, 8 deletions
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 7fa676f93ac1..42a601673c09 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -526,8 +526,6 @@ static inline int fpregs_state_valid(struct fpu *fpu, unsigned int cpu) */ static inline void fpregs_deactivate(struct fpu *fpu) { - WARN_ON_FPU(!fpu->fpregs_active); - fpu->fpregs_active = 0; this_cpu_write(fpu_fpregs_owner_ctx, NULL); trace_x86_fpu_regs_deactivated(fpu); @@ -535,8 +533,6 @@ static inline void fpregs_deactivate(struct fpu *fpu) static inline void fpregs_activate(struct fpu *fpu) { - WARN_ON_FPU(fpu->fpregs_active); - fpu->fpregs_active = 1; this_cpu_write(fpu_fpregs_owner_ctx, fpu); trace_x86_fpu_regs_activated(fpu); @@ -604,8 +600,7 @@ static inline void user_fpu_begin(void) struct fpu *fpu = ¤t->thread.fpu; preempt_disable(); - if (!fpu->fpregs_active) - fpregs_activate(fpu); + fpregs_activate(fpu); preempt_enable(); } diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index eab244622402..01a47e9edfb4 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -426,8 +426,7 @@ void fpu__drop(struct fpu *fpu) asm volatile("1: fwait\n" "2:\n" _ASM_EXTABLE(1b, 2b)); - if (fpu->fpregs_active) - fpregs_deactivate(fpu); + fpregs_deactivate(fpu); } } else { WARN_ON_FPU(fpu->fpregs_active); |