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Commit 6ffc152e authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/fpu: Move all the fpu__*() high level methods closer to each other 



The fpu__*() methods are closely related, but they are defined
in scattered places within the FPU code.

Concentrate them, and also uninline fpu__save(), fpu__drop()
and fpu__reset() to save about 5K of kernel text on 64-bit kernels:

   text            data    bss     dec        filename
   14113063        2575280 1634304 18322647   vmlinux.before
   14108070        2575280 1634304 18317654   vmlinux.after

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: default avatarIngo Molnar <mingo@kernel.org>
parent 0e75c54f

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

+10 −43
Original line number Diff line number Diff line
@@ -46,10 +46,19 @@ extern void fpu__init_system(struct cpuinfo_x86 *c); 


extern void fpu__activate_curr(struct fpu *fpu);

extern void fpstate_init(struct fpu *fpu);

extern void fpu__clear(struct task_struct *tsk);



extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);



/*

 * High level FPU state handling functions:

 */

extern void fpu__save(struct fpu *fpu);

extern void fpu__restore(void);

extern void fpu__drop(struct fpu *fpu);

extern int  fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu);

extern void fpu__reset(struct fpu *fpu);

extern void fpu__clear(struct task_struct *tsk);



extern void fpu__init_check_bugs(void);

extern void fpu__resume_cpu(void);
@@ -287,8 +296,6 @@ static inline int copy_fpregs_to_fpstate(struct fpu *fpu) 
	return 0;

}



extern void fpu__save(struct fpu *fpu);



static inline int __copy_fpstate_to_fpregs(struct fpu *fpu)

{

	if (use_xsave())
@@ -382,33 +389,6 @@ static inline void fpregs_deactivate(struct fpu *fpu) 
	__fpregs_deactivate_hw();

}



/*

 * Drops current FPU state: deactivates the fpregs and

 * the fpstate. NOTE: it still leaves previous contents

 * in the fpregs in the eager-FPU case.

 *

 * This function can be used in cases where we know that

 * a state-restore is coming: either an explicit one,

 * or a reschedule.

 */

static inline void fpu__drop(struct fpu *fpu)

{

	preempt_disable();

	fpu->counter = 0;



	if (fpu->fpregs_active) {

		/* Ignore delayed exceptions from user space */

		asm volatile("1: fwait\n"

			     "2:\n"

			     _ASM_EXTABLE(1b, 2b));

		fpregs_deactivate(fpu);

	}



	fpu->fpstate_active = 0;



	preempt_enable();

}



static inline void restore_init_xstate(void)

{

	if (use_xsave())
@@ -417,17 +397,6 @@ static inline void restore_init_xstate(void) 
		fxrstor_checking(&init_xstate_ctx.i387);

}



/*

 * Reset the FPU state back to init state.

 */

static inline void fpu__reset(struct fpu *fpu)

{

	if (!use_eager_fpu())

		fpu__drop(fpu);

	else

		restore_init_xstate();

}



/*

 * Definitions for the eXtended Control Register instructions

 */
@@ -597,8 +566,6 @@ static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk) 
	}

}



extern int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu);



static inline unsigned long

alloc_mathframe(unsigned long sp, int ia32_frame, unsigned long *buf_fx,

		unsigned long *size)

arch/x86/kernel/fpu/core.c

+38 −0
Original line number Diff line number Diff line
@@ -348,6 +348,44 @@ void fpu__restore(void) 
}

EXPORT_SYMBOL_GPL(fpu__restore);



/*

 * Drops current FPU state: deactivates the fpregs and

 * the fpstate. NOTE: it still leaves previous contents

 * in the fpregs in the eager-FPU case.

 *

 * This function can be used in cases where we know that

 * a state-restore is coming: either an explicit one,

 * or a reschedule.

 */

void fpu__drop(struct fpu *fpu)

{

	preempt_disable();

	fpu->counter = 0;



	if (fpu->fpregs_active) {

		/* Ignore delayed exceptions from user space */

		asm volatile("1: fwait\n"

			     "2:\n"

			     _ASM_EXTABLE(1b, 2b));

		fpregs_deactivate(fpu);

	}



	fpu->fpstate_active = 0;



	preempt_enable();

}



/*

 * Reset the FPU state back to init state:

 */

void fpu__reset(struct fpu *fpu)

{

	if (!use_eager_fpu())

		fpu__drop(fpu);

	else

		restore_init_xstate();

}



/*

 * Called by sys_execve() to clear the FPU fpregs, so that FPU state

 * of the previous binary does not leak over into the exec()ed binary: