[PATCH v4 7/8] powerpc/vdso32: implement clock_getres entirely

[Christophe Leroy]

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.le...@c-s.fr>
---
 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 0013197d89a6..90e53d432f2e 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -413,7 +413,10 @@ 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 9aafacea9c4a..20ae38f3a5a3 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -196,17 +196,20 @@ 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
@@ -215,11 +218,11 @@ 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