diff options
| author | Paul Mackerras <paulus@samba.org> | 2014-05-26 19:48:40 +1000 |
|---|---|---|
| committer | Alexander Graf <agraf@suse.de> | 2014-05-30 14:26:29 +0200 |
| commit | 9bc01a9bc77edac2ea6db62c5111a7f4335d4021 (patch) | |
| tree | 302ce7b1b9e01ef8489d65083300c96a151c390d /arch/powerpc/include | |
| parent | 6c576e74fd91b93ca1eedcd9eb5200171d2ba32b (diff) | |
KVM: PPC: Book3S HV: Work around POWER8 performance monitor bugs
This adds workarounds for two hardware bugs in the POWER8 performance
monitor unit (PMU), both related to interrupt generation. The effect
of these bugs is that PMU interrupts can get lost, leading to tools
such as perf reporting fewer counts and samples than they should.
The first bug relates to the PMAO (perf. mon. alert occurred) bit in
MMCR0; setting it should cause an interrupt, but doesn't. The other
bug relates to the PMAE (perf. mon. alert enable) bit in MMCR0.
Setting PMAE when a counter is negative and counter negative
conditions are enabled to cause alerts should cause an alert, but
doesn't.
The workaround for the first bug is to create conditions where a
counter will overflow, whenever we are about to restore a MMCR0
value that has PMAO set (and PMAO_SYNC clear). The workaround for
the second bug is to freeze all counters using MMCR2 before reading
MMCR0.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/reg.h | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index e5d2e0bc7e03..4852bcf270f3 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -670,18 +670,20 @@ #define MMCR0_PROBLEM_DISABLE MMCR0_FCP #define MMCR0_FCM1 0x10000000UL /* freeze counters while MSR mark = 1 */ #define MMCR0_FCM0 0x08000000UL /* freeze counters while MSR mark = 0 */ -#define MMCR0_PMXE 0x04000000UL /* performance monitor exception enable */ -#define MMCR0_FCECE 0x02000000UL /* freeze ctrs on enabled cond or event */ +#define MMCR0_PMXE ASM_CONST(0x04000000) /* perf mon exception enable */ +#define MMCR0_FCECE ASM_CONST(0x02000000) /* freeze ctrs on enabled cond or event */ #define MMCR0_TBEE 0x00400000UL /* time base exception enable */ #define MMCR0_BHRBA 0x00200000UL /* BHRB Access allowed in userspace */ #define MMCR0_EBE 0x00100000UL /* Event based branch enable */ #define MMCR0_PMCC 0x000c0000UL /* PMC control */ #define MMCR0_PMCC_U6 0x00080000UL /* PMC1-6 are R/W by user (PR) */ #define MMCR0_PMC1CE 0x00008000UL /* PMC1 count enable*/ -#define MMCR0_PMCjCE 0x00004000UL /* PMCj count enable*/ +#define MMCR0_PMCjCE ASM_CONST(0x00004000) /* PMCj count enable*/ #define MMCR0_TRIGGER 0x00002000UL /* TRIGGER enable */ -#define MMCR0_PMAO_SYNC 0x00000800UL /* PMU interrupt is synchronous */ -#define MMCR0_PMAO 0x00000080UL /* performance monitor alert has occurred, set to 0 after handling exception */ +#define MMCR0_PMAO_SYNC ASM_CONST(0x00000800) /* PMU intr is synchronous */ +#define MMCR0_C56RUN ASM_CONST(0x00000100) /* PMC5/6 count when RUN=0 */ +/* performance monitor alert has occurred, set to 0 after handling exception */ +#define MMCR0_PMAO ASM_CONST(0x00000080) #define MMCR0_SHRFC 0x00000040UL /* SHRre freeze conditions between threads */ #define MMCR0_FC56 0x00000010UL /* freeze counters 5 and 6 */ #define MMCR0_FCTI 0x00000008UL /* freeze counters in tags inactive mode */ |