x86/fpu: Eliminate the __thread_has_fpu() wrapper

Start migrating FPU methods towards using 'struct fpu *fpu'
directly. __thread_has_fpu() is just a trivial wrapper around
fpu->has_fpu, eliminate it.

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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index e180fb96dd0d9afc624aefe0736a6c1ea3637298..c005d1fc12478d7a437fd26c441fba64dbb600bf 100644 (file)
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -323,16 +323,6 @@ static inline int restore_fpu_checking(struct task_struct *tsk)
        return fpu_restore_checking(&tsk->thread.fpu);
 }
 
-/*
- * Software FPU state helpers. Careful: these need to
- * be preemption protection *and* they need to be
- * properly paired with the CR0.TS changes!
- */
-static inline int __thread_has_fpu(struct task_struct *tsk)
-{
-       return tsk->thread.fpu.has_fpu;
-}
-
 /* Must be paired with an 'stts' after! */
 static inline void __thread_clear_has_fpu(struct task_struct *tsk)
 {
@@ -370,13 +360,14 @@ static inline void __thread_fpu_begin(struct task_struct *tsk)
 
 static inline void drop_fpu(struct task_struct *tsk)
 {
+       struct fpu *fpu = &tsk->thread.fpu;
        /*
         * Forget coprocessor state..
         */
        preempt_disable();
        tsk->thread.fpu.counter = 0;
 
-       if (__thread_has_fpu(tsk)) {
+       if (fpu->has_fpu) {
                /* Ignore delayed exceptions from user space */
                asm volatile("1: fwait\n"
                             "2:\n"
@@ -424,6 +415,7 @@ typedef struct { int preload; } fpu_switch_t;
 
 static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct task_struct *new, int cpu)
 {
+       struct fpu *old_fpu = &old->thread.fpu;
        fpu_switch_t fpu;
 
        /*
@@ -433,7 +425,7 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta
        fpu.preload = tsk_used_math(new) &&
                      (use_eager_fpu() || new->thread.fpu.counter > 5);
 
-       if (__thread_has_fpu(old)) {
+       if (old_fpu->has_fpu) {
                if (!fpu_save_init(&old->thread.fpu))
                        task_disable_lazy_fpu_restore(old);
                else

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 3aeab3f12835cddd647e6a890694e3e96b041e45..29b837730a0713ff79391e17849fea5616a183ad 100644 (file)
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -57,8 +57,7 @@ static bool interrupted_kernel_fpu_idle(void)
        if (use_eager_fpu())
                return true;
 
-       return !__thread_has_fpu(current) &&
-               (read_cr0() & X86_CR0_TS);
+       return !current->thread.fpu.has_fpu && (read_cr0() & X86_CR0_TS);
 }
 
 /*
@@ -93,11 +92,12 @@ EXPORT_SYMBOL(irq_fpu_usable);
 void __kernel_fpu_begin(void)
 {
        struct task_struct *me = current;
+       struct fpu *fpu = &me->thread.fpu;
 
        kernel_fpu_disable();
 
-       if (__thread_has_fpu(me)) {
-               fpu_save_init(&me->thread.fpu);
+       if (fpu->has_fpu) {
+               fpu_save_init(fpu);
        } else {
                this_cpu_write(fpu_owner_task, NULL);
                if (!use_eager_fpu())
@@ -109,8 +109,9 @@ EXPORT_SYMBOL(__kernel_fpu_begin);
 void __kernel_fpu_end(void)
 {
        struct task_struct *me = current;
+       struct fpu *fpu = &me->thread.fpu;
 
-       if (__thread_has_fpu(me)) {
+       if (fpu->has_fpu) {
                if (WARN_ON(restore_fpu_checking(me)))
                        fpu_reset_state(me);
        } else if (!use_eager_fpu()) {
@@ -128,14 +129,16 @@ EXPORT_SYMBOL(__kernel_fpu_end);
  */
 void fpu__save(struct task_struct *tsk)
 {
+       struct fpu *fpu = &tsk->thread.fpu;
+
        WARN_ON(tsk != current);
 
        preempt_disable();
-       if (__thread_has_fpu(tsk)) {
+       if (fpu->has_fpu) {
                if (use_eager_fpu()) {
                        __save_fpu(tsk);
                } else {
-                       fpu_save_init(&tsk->thread.fpu);
+                       fpu_save_init(fpu);
                        __thread_fpu_end(tsk);
                }
        }