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| author | Rik van Riel <riel@redhat.com> | 2016-10-14 15:15:30 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-10-16 12:38:31 +0300 |
| commit | 317b622cb2fda1812d8646e211cdb23dce2564d0 (patch) | |
| tree | 07762110cae03a11c03b31c13468d265cdb0f1f4 /arch | |
| parent | 9ad93fe35aff616fca4e2b9581fdeed498605f9e (diff) | |
| download | linux-317b622cb2fda1812d8646e211cdb23dce2564d0.tar.xz | |
x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state()
The __{fpu,cpu}_invalidate_fpregs_state() functions can only be used
to invalidate a resource they control. Document that, and change
the API a little bit to reflect that.
Go back to open coding the fpu_fpregs_owner_ctx write in the CPU
hotplug code, which should be the exception, and move __kernel_fpu_begin()
to this API.
This patch has no functional changes to the current code.
Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1476447331-21566-2-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/fpu/internal.h | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 2 |
3 files changed, 9 insertions, 8 deletions
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 1dcb29e8d92c..590f27488fca 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -488,15 +488,16 @@ DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); * * 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or updates the in-memory * FPU state for a task MUST let the rest of the kernel know that the - * FPU registers are no longer valid for this task. Calling either of - * these two invalidate functions is enough, use whichever is convenient. + * FPU registers are no longer valid for this task. * - * Must be run with preemption disabled: this clears the fpu_fpregs_owner_ctx, - * on this CPU. + * 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(unsigned int cpu) +static inline void __cpu_invalidate_fpregs_state(void) { - per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL; + __this_cpu_write(fpu_fpregs_owner_ctx, NULL); } static inline void __fpu_invalidate_fpregs_state(struct fpu *fpu) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 25a45ddfdbcf..30f11ab6c07e 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -106,7 +106,7 @@ void __kernel_fpu_begin(void) */ copy_fpregs_to_fpstate(fpu); } else { - this_cpu_write(fpu_fpregs_owner_ctx, NULL); + __cpu_invalidate_fpregs_state(); } } EXPORT_SYMBOL(__kernel_fpu_begin); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index ca4c4ca2f6af..5cb801acc2e5 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1111,7 +1111,7 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle) return err; /* the FPU context is blank, nobody can own it */ - __cpu_invalidate_fpregs_state(cpu); + per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL; common_cpu_up(cpu, tidle); |