3.16.82-rc1 review patch. If anyone has any objections, please let me know.
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From: Vincenzo Frascino vincenzo.frascino@arm.com
commit 552263456215ada7ee8700ce022d12b0cffe4802 upstream.
clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res().
In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time.
Fix the powerpc vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly.
Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel") Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com Reviewed-by: Christophe Leroy christophe.leroy@c-s.fr Acked-by: Shuah Khan skhan@linuxfoundation.org [chleroy: changed CLOCK_REALTIME_RES to CLOCK_HRTIMER_RES] Signed-off-by: Christophe Leroy christophe.leroy@c-s.fr Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/a55eca3a5e85233838c2349783bcb5164dae1d09.157527321... [bwh: Backported to 3.16: - In asm-offsets.c, use DEFINE() instead of OFFSET() - Adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/powerpc/include/asm/vdso_datapage.h | 2 ++ arch/powerpc/kernel/asm-offsets.c | 2 +- arch/powerpc/kernel/time.c | 1 + arch/powerpc/kernel/vdso32/gettimeofday.S | 7 +++++-- arch/powerpc/kernel/vdso64/gettimeofday.S | 7 +++++-- 5 files changed, 14 insertions(+), 5 deletions(-)
--- a/arch/powerpc/include/asm/vdso_datapage.h +++ b/arch/powerpc/include/asm/vdso_datapage.h @@ -86,6 +86,7 @@ struct vdso_data { __s32 wtom_clock_nsec; /* Wall to monotonic clock nsec */ __s64 wtom_clock_sec; /* Wall to monotonic clock sec */ struct timespec stamp_xtime; /* xtime as at tb_orig_stamp */ + __u32 hrtimer_res; /* hrtimer resolution */ __u32 syscall_map_64[SYSCALL_MAP_SIZE]; /* map of syscalls */ __u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */ }; @@ -107,6 +108,7 @@ struct vdso_data { __s32 wtom_clock_nsec; struct timespec stamp_xtime; /* xtime as at tb_orig_stamp */ __u32 stamp_sec_fraction; /* fractional seconds of stamp_xtime */ + __u32 hrtimer_res; /* hrtimer resolution */ __u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */ __u32 dcache_block_size; /* L1 d-cache block size */ __u32 icache_block_size; /* L1 i-cache block size */ --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -397,6 +397,7 @@ int main(void) DEFINE(WTOM_CLOCK_NSEC, offsetof(struct vdso_data, wtom_clock_nsec)); DEFINE(STAMP_XTIME, offsetof(struct vdso_data, stamp_xtime)); DEFINE(STAMP_SEC_FRAC, offsetof(struct vdso_data, stamp_sec_fraction)); + DEFINE(CLOCK_HRTIMER_RES, offsetof(struct vdso_data, hrtimer_res)); DEFINE(CFG_ICACHE_BLOCKSZ, offsetof(struct vdso_data, icache_block_size)); DEFINE(CFG_DCACHE_BLOCKSZ, offsetof(struct vdso_data, dcache_block_size)); DEFINE(CFG_ICACHE_LOGBLOCKSZ, offsetof(struct vdso_data, icache_log_block_size)); @@ -425,7 +426,6 @@ int main(void) DEFINE(CLOCK_REALTIME, CLOCK_REALTIME); DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC); DEFINE(NSEC_PER_SEC, NSEC_PER_SEC); - DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC);
#ifdef CONFIG_BUG DEFINE(BUG_ENTRY_SIZE, sizeof(struct bug_entry)); --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -781,6 +781,7 @@ void update_vsyscall_old(struct timespec vdso_data->wtom_clock_nsec = wtm->tv_nsec; vdso_data->stamp_xtime = *wall_time; vdso_data->stamp_sec_fraction = frac_sec; + vdso_data->hrtimer_res = hrtimer_resolution; smp_wmb(); ++(vdso_data->tb_update_count); } --- a/arch/powerpc/kernel/vdso32/gettimeofday.S +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S @@ -159,12 +159,15 @@ V_FUNCTION_BEGIN(__kernel_clock_getres) cror cr0*4+eq,cr0*4+eq,cr1*4+eq bne cr0,99f
+ mflr r12 + .cfi_register lr,r12 + bl __get_datapage@local /* get data page */ + lwz r5, CLOCK_HRTIMER_RES(r3) + mtlr r12 li r3,0 cmpli cr0,r4,0 crclr cr0*4+so beqlr - lis r5,CLOCK_REALTIME_RES@h - ori r5,r5,CLOCK_REALTIME_RES@l stw r3,TSPC32_TV_SEC(r4) stw r5,TSPC32_TV_NSEC(r4) blr --- a/arch/powerpc/kernel/vdso64/gettimeofday.S +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S @@ -144,12 +144,15 @@ V_FUNCTION_BEGIN(__kernel_clock_getres) cror cr0*4+eq,cr0*4+eq,cr1*4+eq bne cr0,99f
+ mflr r12 + .cfi_register lr,r12 + bl V_LOCAL_FUNC(__get_datapage) + lwz r5, CLOCK_HRTIMER_RES(r3) + mtlr r12 li r3,0 cmpldi cr0,r4,0 crclr cr0*4+so beqlr - lis r5,CLOCK_REALTIME_RES@h - ori r5,r5,CLOCK_REALTIME_RES@l std r3,TSPC64_TV_SEC(r4) std r5,TSPC64_TV_NSEC(r4) blr