diff options
| author | Ingo Molnar | 2015-05-05 11:34:49 +0200 |
|---|---|---|
| committer | Ingo Molnar | 2015-05-19 15:48:12 +0200 |
| commit | e97131a8391e9fce5126ed54dc66c9d8965d3b4e (patch) | |
| tree | 8e1db79ae5c956db9a329ed1d76891d7c12535fd /arch/x86/include/asm | |
| parent | x86/fpu: Fix the 'nofxsr' boot parameter to also clear X86_FEATURE_FXSR_OPT (diff) | |
| download | kernel-qcow2-linux-e97131a8391e9fce5126ed54dc66c9d8965d3b4e.tar.gz kernel-qcow2-linux-e97131a8391e9fce5126ed54dc66c9d8965d3b4e.tar.xz kernel-qcow2-linux-e97131a8391e9fce5126ed54dc66c9d8965d3b4e.zip | |
x86/fpu: Add CONFIG_X86_DEBUG_FPU=y FPU debugging code
There are various internal FPU state debugging checks that never
trigger in practice, but which are useful for FPU code development.
Separate these out into CONFIG_X86_DEBUG_FPU=y, and also add a
couple of new ones.
The size difference is about 0.5K of code on defconfig:
text data bss filename
15028906 2578816 1638400 vmlinux
15029430 2578816 1638400 vmlinux
( Keep this enabled by default until the new FPU code is debugged. )
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/fpu/internal.h | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index a4c1b7dbf70e..d2a281bd5f45 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -59,6 +59,15 @@ extern void fpu__clear(struct fpu *fpu); extern void fpu__init_check_bugs(void); extern void fpu__resume_cpu(void); +/* + * Debugging facility: + */ +#ifdef CONFIG_X86_DEBUG_FPU +# define WARN_ON_FPU(x) WARN_ON_ONCE(x) +#else +# define WARN_ON_FPU(x) ({ 0; }) +#endif + DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); /* @@ -296,6 +305,8 @@ static inline void __fpregs_deactivate_hw(void) /* Must be paired with an 'stts' (fpregs_deactivate_hw()) after! */ 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); } @@ -303,6 +314,8 @@ static inline void __fpregs_deactivate(struct fpu *fpu) /* Must be paired with a 'clts' (fpregs_activate_hw()) before! */ 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); } @@ -433,8 +446,10 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu) static inline void switch_fpu_finish(struct fpu *new_fpu, fpu_switch_t fpu_switch) { if (fpu_switch.preload) { - if (unlikely(copy_fpstate_to_fpregs(new_fpu))) + if (unlikely(copy_fpstate_to_fpregs(new_fpu))) { + WARN_ON_FPU(1); fpu__clear(new_fpu); + } } } |