[PATCH 060/208] x86/fpu: Use 'struct fpu' in switch_fpu_prepare()

Ingo Molnar
2015-05-05T16:29:26Z

Migrate this function to pure 'struct fpu' usage.

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/include/asm/fpu-internal.h | 27 +++++++++++++--------------
arch/x86/kernel/process_32.c | 2 +-
arch/x86/kernel/process_64.c | 2 +-
3 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 579f7d0a399d..60d2c6f376f3 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -402,10 +402,9 @@ static inline void fpu_reset_state(struct fpu *fpu)
*/
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)
+static inline fpu_switch_t
+switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu)
{
- struct fpu *old_fpu = &old->thread.fpu;
- struct fpu *new_fpu = &new->thread.fpu;
fpu_switch_t fpu;

/*
@@ -413,33 +412,33 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta
* or if the past 5 consecutive context-switches used math.
*/
fpu.preload = new_fpu->fpstate_active &&
- (use_eager_fpu() || new->thread.fpu.counter > 5);
+ (use_eager_fpu() || new_fpu->counter > 5);

if (old_fpu->has_fpu) {
- if (!fpu_save_init(&old->thread.fpu))
- old->thread.fpu.last_cpu = -1;
+ if (!fpu_save_init(old_fpu))
+ old_fpu->last_cpu = -1;
else
- old->thread.fpu.last_cpu = cpu;
+ old_fpu->last_cpu = cpu;

/* But leave fpu_fpregs_owner_ctx! */
- old->thread.fpu.has_fpu = 0;
+ old_fpu->has_fpu = 0;

/* Don't change CR0.TS if we just switch! */
if (fpu.preload) {
- new->thread.fpu.counter++;
+ new_fpu->counter++;
__thread_set_has_fpu(new_fpu);
- prefetch(new->thread.fpu.state);
+ prefetch(new_fpu->state);
} else if (!use_eager_fpu())
stts();
} else {
- old->thread.fpu.counter = 0;
- old->thread.fpu.last_cpu = -1;
+ old_fpu->counter = 0;
+ old_fpu->last_cpu = -1;
if (fpu.preload) {
- new->thread.fpu.counter++;
+ new_fpu->counter++;
if (fpu_want_lazy_restore(new_fpu, cpu))
fpu.preload = 0;
else
- prefetch(new->thread.fpu.state);
+ prefetch(new_fpu->state);
__thread_fpu_begin(new_fpu);
}
}
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 1a0edce626b2..5b0ed71dde60 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -248,7 +248,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)

/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */

- fpu = switch_fpu_prepare(prev_p, next_p, cpu);
+ fpu = switch_fpu_prepare(&prev_p->thread.fpu, &next_p->thread.fpu, cpu);

/*
* Save away %gs. No need to save %fs, as it was saved on the
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 99cc4b8589ad..fefe65efd9d6 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -278,7 +278,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
unsigned fsindex, gsindex;
fpu_switch_t fpu;

- fpu = switch_fpu_prepare(prev_p, next_p, cpu);
+ fpu = switch_fpu_prepare(&prev_p->thread.fpu, &next_p->thread.fpu, cpu);

/* We must save %fs and %gs before load_TLS() because
* %fs and %gs may be cleared by load_TLS().
--
2.1.0