Michael Ellerman [mich...@ellerman.id.au] wrote:
| From: Michael Ellerman <micha...@au1.ibm.com>
|
| On power8 we have a new SIER (Sampled Instruction Event Register), which
| captures information about instructions when we have random sampling
| enabled.
|
| Add support for loading the SIER into pt_regs, overloading regs->dar.
| Also set the new NO_SIPR flag in regs->result if we don't have SIPR.
|
| Update regs_sihv/sipr() to look for SIPR/SIHV in SIER.
|
| Signed-off-by: Michael Ellerman <micha...@au1.ibm.com>
| ---
| arch/powerpc/include/asm/perf_event_server.h | 1 +
| arch/powerpc/perf/core-book3s.c | 19 +++++++++++++++++++
| 2 files changed, 20 insertions(+)
|
| diff --git a/arch/powerpc/include/asm/perf_event_server.h
b/arch/powerpc/include/asm/perf_event_server.h
| index e287aef..a1a1ad8 100644
| --- a/arch/powerpc/include/asm/perf_event_server.h
| +++ b/arch/powerpc/include/asm/perf_event_server.h
| @@ -53,6 +53,7 @@ struct power_pmu {
| #define PPMU_NO_CONT_SAMPLING 0x00000008 /* no continuous sampling */
| #define PPMU_SIAR_VALID 0x00000010 /* Processor has SIAR Valid
bit */
| #define PPMU_HAS_SSLOT 0x00000020 /* Has sampled slot in MMCRA
*/
| +#define PPMU_HAS_SIER 0x00000040 /* Has SIER */
|
| /*
| * Values for flags to get_alternatives()
| diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
| index 4255b12..a4bbd4d 100644
| --- a/arch/powerpc/perf/core-book3s.c
| +++ b/arch/powerpc/perf/core-book3s.c
| @@ -116,6 +116,9 @@ static bool regs_sihv(struct pt_regs *regs)
| {
| unsigned long sihv = MMCRA_SIHV;
|
| + if (ppmu->flags & PPMU_HAS_SIER)
| + return !!(regs->dar & SIER_SIHV);
| +
Were SIER_SIHV and SIER_SIPR defined in an earlier patch set ?
| if (ppmu->flags & PPMU_ALT_SIPR)
| sihv = POWER6_MMCRA_SIHV;
|
| @@ -126,6 +129,9 @@ static bool regs_sipr(struct pt_regs *regs)
| {
| unsigned long sipr = MMCRA_SIPR;
|
| + if (ppmu->flags & PPMU_HAS_SIER)
| + return !!(regs->dar & SIER_SIPR);
| +
| if (ppmu->flags & PPMU_ALT_SIPR)
| sipr = POWER6_MMCRA_SIPR;
|
| @@ -184,6 +190,7 @@ static inline u32 perf_get_misc_flags(struct pt_regs
*regs)
| /*
| * Overload regs->dsisr to store MMCRA so we only need to read it once
| * on each interrupt.
| + * Overload regs->dar to store SIER if we have it.
| * Overload regs->result to specify whether we should use the MSR (result
| * is zero) or the SIAR (result is non zero).
| */
| @@ -200,6 +207,18 @@ static inline void perf_read_regs(struct pt_regs *regs)
| regs->result |= 2;
|
| /*
| + * On power8 if we're in random sampling mode, the SIER is updated.
| + * If we're in continuous sampling mode, we don't have SIPR.
| + */
| + if (ppmu->flags & PPMU_HAS_SIER) {
| + if (marked)
| + regs->dar = mfspr(SPRN_SIER);
| + else
| + regs->result |= 2;
Can we use a helper, regs_set_no_sipr() to set this - since we set and
test in more than one place ?
Other than these nits, the patchset looks good.
Sukadev
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