[PATCH v2 7/8] powerpc/vdso32: implement clock_getres entirely

From: Christophe Leroy
Date: Thu Aug 22 2019 - 12:34:22 EST


clock_getres returns hrtimer_res for all clocks but coarse ones
for which it returns KTIME_LOW_RES.

return EINVAL for unknown clocks.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/kernel/asm-offsets.c | 3 +++
arch/powerpc/kernel/vdso32/gettimeofday.S | 19 +++++++++++--------
2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index b6328a90cad7..dbfd3ddc85dc 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -417,7 +417,10 @@ int main(void)
DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC);
DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE);
DEFINE(CLOCK_MONOTONIC_COARSE, CLOCK_MONOTONIC_COARSE);
+ DEFINE(CLOCK_MAX, CLOCK_TAI);
DEFINE(NSEC_PER_SEC, NSEC_PER_SEC);
+ DEFINE(EINVAL, EINVAL);
+ DEFINE(KTIME_LOW_RES, KTIME_LOW_RES);

#ifdef CONFIG_BUG
DEFINE(BUG_ENTRY_SIZE, sizeof(struct bug_entry));
diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
index 0f87be0ebf7e..c65f41c612f7 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -199,17 +199,20 @@ V_FUNCTION_END(__kernel_clock_gettime)
V_FUNCTION_BEGIN(__kernel_clock_getres)
.cfi_startproc
/* Check for supported clock IDs */
- cmpwi cr0,r3,CLOCK_REALTIME
- cmpwi cr1,r3,CLOCK_MONOTONIC
- cror cr0*4+eq,cr0*4+eq,cr1*4+eq
- bne cr0,99f
+ cmplwi cr0, r3, CLOCK_MAX
+ cmpwi cr1, r3, CLOCK_REALTIME_COARSE
+ cmpwi cr7, r3, CLOCK_MONOTONIC_COARSE
+ bgt cr0, 99f
+ LOAD_REG_IMMEDIATE(r5, KTIME_LOW_RES)
+ beq cr1, 1f
+ beq cr7, 1f

mflr r12
.cfi_register lr,r12
get_datapage r3, r0
lwz r5, CLOCK_HRTIMER_RES(r3)
mtlr r12
- li r3,0
+1: li r3,0
cmpli cr0,r4,0
crclr cr0*4+so
beqlr
@@ -218,11 +221,11 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
blr

/*
- * syscall fallback
+ * invalid clock
*/
99:
- li r0,__NR_clock_getres
- sc
+ li r3, EINVAL
+ crset so
blr
.cfi_endproc
V_FUNCTION_END(__kernel_clock_getres)
--
2.13.3