Messages in this thread Patch in this message | | | From | Ingo Molnar <> | Subject | [PATCH 040/208] x86/fpu: Add kernel_fpu_disabled() | Date | Tue, 5 May 2015 18:24:20 +0200 |
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Instead of open-coded in_kernel_fpu access, Use kernel_fpu_disabled() in interrupted_kernel_fpu_idle(), matching the other kernel_fpu_*() methods.
Also add some documentation for in_kernel_fpu.
Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/fpu/core.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index bcf705751d02..87f10b49da47 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -7,6 +7,17 @@ */ #include <asm/fpu-internal.h> +/* + * Track whether the kernel is using the FPU state + * currently. + * + * This flag is used: + * + * - by IRQ context code to potentially use the FPU + * if it's unused. + * + * - to debug kernel_fpu_begin()/end() correctness + */ static DEFINE_PER_CPU(bool, in_kernel_fpu); static void kernel_fpu_disable(void) @@ -21,6 +32,11 @@ static void kernel_fpu_enable(void) this_cpu_write(in_kernel_fpu, false); } +static bool kernel_fpu_disabled(void) +{ + return this_cpu_read(in_kernel_fpu); +} + /* * Were we in an interrupt that interrupted kernel mode? * @@ -35,7 +51,7 @@ static void kernel_fpu_enable(void) */ static bool interrupted_kernel_fpu_idle(void) { - if (this_cpu_read(in_kernel_fpu)) + if (kernel_fpu_disabled()) return false; if (use_eager_fpu()) -- 2.1.0
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