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Commit 794b88e0 authored by David S. Miller's avatar David S. Miller
Browse files

sparc: Inline VDSO gettime code aggressively. 



One interesting thing we need to do is stop using
__builtin_return_address() in get_vvar_data().

Simply read the %pc register instead.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2f6c9bf3

arch/sparc/vdso/vclock_gettime.c

+17 −22
Original line number Diff line number Diff line
@@ -60,24 +60,22 @@ 
 * Compute the vvar page's address in the process address space, and return it

 * as a pointer to the vvar_data.

 */

static notrace noinline struct vvar_data *

get_vvar_data(void)

notrace static __always_inline struct vvar_data *get_vvar_data(void)

{

	unsigned long ret;



	/*

	 * vdso data page is the first vDSO page so grab the return address

	 * vdso data page is the first vDSO page so grab the PC

	 * and move up a page to get to the data page.

	 */

	ret = (unsigned long)__builtin_return_address(0);

	__asm__("rd %%pc, %0" : "=r" (ret));

	ret &= ~(8192 - 1);

	ret -= 8192;



	return (struct vvar_data *) ret;

}



static notrace long

vdso_fallback_gettime(long clock, struct timespec *ts)

notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)

{

	register long num __asm__("g1") = __NR_clock_gettime;

	register long o0 __asm__("o0") = clock;
@@ -88,8 +86,7 @@ vdso_fallback_gettime(long clock, struct timespec *ts) 
	return o0;

}



static notrace __always_inline long

vdso_fallback_gettimeofday(struct timeval *tv, struct timezone *tz)

notrace static long vdso_fallback_gettimeofday(struct timeval *tv, struct timezone *tz)

{

	register long num __asm__("g1") = __NR_gettimeofday;

	register long o0 __asm__("o0") = (long) tv;
@@ -101,8 +98,8 @@ vdso_fallback_gettimeofday(struct timeval *tv, struct timezone *tz) 
}



#ifdef	CONFIG_SPARC64

static notrace noinline u64

vread_tick(void) {

notrace static __always_inline u64 vread_tick(void)

{

	u64	ret;



	__asm__ __volatile__("1:\n\t"
@@ -118,8 +115,7 @@ vread_tick(void) { 
	return ret & ~TICK_PRIV_BIT;

}

#else

static notrace noinline u64

vread_tick(void)

notrace static __always_inline u64 vread_tick(void)

{

	register unsigned long long ret asm("o4");
@@ -138,8 +134,7 @@ vread_tick(void) 
}

#endif



static notrace inline u64

vgetsns(struct vvar_data *vvar)

notrace static __always_inline u64 vgetsns(struct vvar_data *vvar)

{

	u64 v;

	u64 cycles;
@@ -149,8 +144,8 @@ vgetsns(struct vvar_data *vvar) 
	return v * vvar->clock.mult;

}



static notrace noinline int

do_realtime(struct vvar_data *vvar, struct timespec *ts)

notrace static __always_inline int do_realtime(struct vvar_data *vvar,

					       struct timespec *ts)

{

	unsigned long seq;

	u64 ns;
@@ -169,8 +164,8 @@ do_realtime(struct vvar_data *vvar, struct timespec *ts) 
	return 0;

}



static notrace noinline int

do_monotonic(struct vvar_data *vvar, struct timespec *ts)

notrace static __always_inline int do_monotonic(struct vvar_data *vvar,

						struct timespec *ts)

{

	unsigned long seq;

	u64 ns;
@@ -189,8 +184,8 @@ do_monotonic(struct vvar_data *vvar, struct timespec *ts) 
	return 0;

}



static notrace noinline int

do_realtime_coarse(struct vvar_data *vvar, struct timespec *ts)

notrace static int do_realtime_coarse(struct vvar_data *vvar,

				      struct timespec *ts)

{

	unsigned long seq;
@@ -202,8 +197,8 @@ do_realtime_coarse(struct vvar_data *vvar, struct timespec *ts) 
	return 0;

}



static notrace noinline int

do_monotonic_coarse(struct vvar_data *vvar, struct timespec *ts)

notrace static int do_monotonic_coarse(struct vvar_data *vvar,

				       struct timespec *ts)

{

	unsigned long seq;