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Commit cb8818b6 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/fpu: Use 'struct fpu' in switch_fpu_prepare() 



Migrate this function to pure 'struct fpu' usage.

Reviewed-by: default avatarBorislav 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: default avatarIngo Molnar <mingo@kernel.org>
parent af2d94fd

arch/x86/include/asm/fpu-internal.h

+13 −14
Original line number Diff line number Diff line
@@ -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);

		}

	}

arch/x86/kernel/process_32.c

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/x86/kernel/process_64.c

+1 −1
Original line number Diff line number Diff line
@@ -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().