From d5cea9b0af1509f170337ba8f47160d0699ff374 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 24 Apr 2015 14:19:26 +0200 Subject: [PATCH] x86/fpu: Rename fpu->has_fpu to fpu->fpregs_active So the current code uses fpu->has_cpu to determine whether a given user FPU context is actively loaded into the FPU's registers [*] and that those registers represent the task's current FPU state. But this term is not unambiguous: especially the distinction between fpu->has_fpu, PF_USED_MATH and fpu_fpregs_owner_ctx is not clear. Increase clarity by unambigously signalling that it's about hardware registers being active right now, by renaming it to fpu->fpregs_active. ( In later patches we'll use more of the 'fpregs' naming, which will make it easier to grep for as well. ) [*] There's the kernel_fpu_begin()/end() primitive that also activates FPU hw registers as well and uses them, without touching the fpu->fpregs_active flag. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/include/asm/fpu/api.h | 2 +- arch/x86/include/asm/fpu/internal.h | 12 ++++++------ arch/x86/include/asm/fpu/types.h | 2 +- arch/x86/kernel/fpu/core.c | 10 +++++----- 4 files changed, 13 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 5bdde8c..4ca745c 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -96,7 +96,7 @@ static inline void irq_ts_restore(int TS_state) */ static inline int user_has_fpu(void) { - return current->thread.fpu.has_fpu; + return current->thread.fpu.fpregs_active; } extern void fpu__save(struct fpu *fpu); diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 6eea81c..b546ec8 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -308,7 +308,7 @@ static inline int restore_fpu_checking(struct fpu *fpu) "fnclex\n\t" "emms\n\t" "fildl %P[addr]" /* set F?P to defined value */ - : : [addr] "m" (fpu->has_fpu)); + : : [addr] "m" (fpu->fpregs_active)); } return fpu_restore_checking(fpu); @@ -317,14 +317,14 @@ static inline int restore_fpu_checking(struct fpu *fpu) /* Must be paired with an 'stts' after! */ static inline void __thread_clear_has_fpu(struct fpu *fpu) { - fpu->has_fpu = 0; + fpu->fpregs_active = 0; this_cpu_write(fpu_fpregs_owner_ctx, NULL); } /* Must be paired with a 'clts' before! */ static inline void __thread_set_has_fpu(struct fpu *fpu) { - fpu->has_fpu = 1; + fpu->fpregs_active = 1; this_cpu_write(fpu_fpregs_owner_ctx, fpu); } @@ -357,7 +357,7 @@ static inline void drop_fpu(struct fpu *fpu) preempt_disable(); fpu->counter = 0; - if (fpu->has_fpu) { + if (fpu->fpregs_active) { /* Ignore delayed exceptions from user space */ asm volatile("1: fwait\n" "2:\n" @@ -416,14 +416,14 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu) fpu.preload = new_fpu->fpstate_active && (use_eager_fpu() || new_fpu->counter > 5); - if (old_fpu->has_fpu) { + if (old_fpu->fpregs_active) { if (!fpu_save_init(old_fpu)) old_fpu->last_cpu = -1; else old_fpu->last_cpu = cpu; /* But leave fpu_fpregs_owner_ctx! */ - old_fpu->has_fpu = 0; + old_fpu->fpregs_active = 0; /* Don't change CR0.TS if we just switch! */ if (fpu.preload) { diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 8a5120a..231a8f5 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -142,7 +142,7 @@ struct fpu { */ unsigned int last_cpu; - unsigned int has_fpu; + unsigned int fpregs_active; union thread_xstate *state; /* * This counter contains the number of consecutive context switches diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 4978a77..c8ae838 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -62,7 +62,7 @@ static bool interrupted_kernel_fpu_idle(void) if (use_eager_fpu()) return true; - return !current->thread.fpu.has_fpu && (read_cr0() & X86_CR0_TS); + return !current->thread.fpu.fpregs_active && (read_cr0() & X86_CR0_TS); } /* @@ -100,7 +100,7 @@ void __kernel_fpu_begin(void) kernel_fpu_disable(); - if (fpu->has_fpu) { + if (fpu->fpregs_active) { fpu_save_init(fpu); } else { this_cpu_write(fpu_fpregs_owner_ctx, NULL); @@ -114,7 +114,7 @@ void __kernel_fpu_end(void) { struct fpu *fpu = ¤t->thread.fpu; - if (fpu->has_fpu) { + if (fpu->fpregs_active) { if (WARN_ON(restore_fpu_checking(fpu))) fpu_reset_state(fpu); } else if (!use_eager_fpu()) { @@ -147,7 +147,7 @@ void fpu__save(struct fpu *fpu) WARN_ON(fpu != ¤t->thread.fpu); preempt_disable(); - if (fpu->has_fpu) { + if (fpu->fpregs_active) { if (use_eager_fpu()) { __save_fpu(fpu); } else { @@ -243,7 +243,7 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu) int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) { dst_fpu->counter = 0; - dst_fpu->has_fpu = 0; + dst_fpu->fpregs_active = 0; dst_fpu->state = NULL; dst_fpu->last_cpu = -1; -- 2.7.4