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SubjectRe: [PATCH V3 1/2] powerpc/perf: Add support for outputting extended regs in perf intr_regs
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On 5/20/20 3:15 PM, Athira Rajeev wrote:
> From: Anju T Sudhakar <anju@linux.vnet.ibm.com>
>
> Add support for perf extended register capability in powerpc.
> The capability flag PERF_PMU_CAP_EXTENDED_REGS, is used to indicate the
> PMU which support extended registers. The generic code define the mask
> of extended registers as 0 for non supported architectures.
>
> Patch adds extended regs support for power9 platform by
> exposing MMCR0, MMCR1 and MMCR2 registers.
>
> REG_RESERVED mask needs update to include extended regs.
> `PERF_REG_EXTENDED_MASK`, contains mask value of the supported registers,
> is defined at runtime in the kernel based on platform since the supported
> registers may differ from one processor version to another and hence the
> MASK value.
>
> with patch
> ----------
>
> available registers: r0 r1 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11
> r12 r13 r14 r15 r16 r17 r18 r19 r20 r21 r22 r23 r24 r25 r26
> r27 r28 r29 r30 r31 nip msr orig_r3 ctr link xer ccr softe
> trap dar dsisr sier mmcra mmcr0 mmcr1 mmcr2
>
> PERF_RECORD_SAMPLE(IP, 0x1): 4784/4784: 0 period: 1 addr: 0
> ... intr regs: mask 0xffffffffffff ABI 64-bit
> .... r0 0xc00000000012b77c
> .... r1 0xc000003fe5e03930
> .... r2 0xc000000001b0e000
> .... r3 0xc000003fdcddf800
> .... r4 0xc000003fc7880000
> .... r5 0x9c422724be
> .... r6 0xc000003fe5e03908
> .... r7 0xffffff63bddc8706
> .... r8 0x9e4
> .... r9 0x0
> .... r10 0x1
> .... r11 0x0
> .... r12 0xc0000000001299c0
> .... r13 0xc000003ffffc4800
> .... r14 0x0
> .... r15 0x7fffdd8b8b00
> .... r16 0x0
> .... r17 0x7fffdd8be6b8
> .... r18 0x7e7076607730
> .... r19 0x2f
> .... r20 0xc00000001fc26c68
> .... r21 0xc0002041e4227e00
> .... r22 0xc00000002018fb60
> .... r23 0x1
> .... r24 0xc000003ffec4d900
> .... r25 0x80000000
> .... r26 0x0
> .... r27 0x1
> .... r28 0x1
> .... r29 0xc000000001be1260
> .... r30 0x6008010
> .... r31 0xc000003ffebb7218
> .... nip 0xc00000000012b910
> .... msr 0x9000000000009033
> .... orig_r3 0xc00000000012b86c
> .... ctr 0xc0000000001299c0
> .... link 0xc00000000012b77c
> .... xer 0x0
> .... ccr 0x28002222
> .... softe 0x1
> .... trap 0xf00
> .... dar 0x0
> .... dsisr 0x80000000000
> .... sier 0x0
> .... mmcra 0x80000000000
> .... mmcr0 0x82008090
> .... mmcr1 0x1e000000
> .... mmcr2 0x0
> ... thread: perf:4784
>
> Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
> [Defined PERF_REG_EXTENDED_MASK at run time to add support for different platforms ]
> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>

Patch looks fine except for couple minor nits (extra tabs and newline
issue).

Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/perf_event_server.h | 8 +++++++
> arch/powerpc/include/uapi/asm/perf_regs.h | 14 +++++++++++-
> arch/powerpc/perf/core-book3s.c | 1 +
> arch/powerpc/perf/perf_regs.c | 34 +++++++++++++++++++++++++---
> arch/powerpc/perf/power9-pmu.c | 6 +++++
> 5 files changed, 59 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
> index 3e9703f..1458e1a 100644
> --- a/arch/powerpc/include/asm/perf_event_server.h
> +++ b/arch/powerpc/include/asm/perf_event_server.h
> @@ -15,6 +15,9 @@
> #define MAX_EVENT_ALTERNATIVES 8
> #define MAX_LIMITED_HWCOUNTERS 2
>
> +extern u64 mask_var;
> +#define PERF_REG_EXTENDED_MASK mask_var
> +
> struct perf_event;
>
> /*
> @@ -55,6 +58,11 @@ struct power_pmu {
> int *blacklist_ev;
> /* BHRB entries in the PMU */
> int bhrb_nr;
> + /*
> + * set this flag with `PERF_PMU_CAP_EXTENDED_REGS` if
> + * the pmu supports extended perf regs capability
> + */
> + int capabilities;
> };
>
> /*
> diff --git a/arch/powerpc/include/uapi/asm/perf_regs.h b/arch/powerpc/include/uapi/asm/perf_regs.h
> index f599064..485b1d5 100644
> --- a/arch/powerpc/include/uapi/asm/perf_regs.h
> +++ b/arch/powerpc/include/uapi/asm/perf_regs.h
> @@ -48,6 +48,18 @@ enum perf_event_powerpc_regs {
> PERF_REG_POWERPC_DSISR,
> PERF_REG_POWERPC_SIER,
> PERF_REG_POWERPC_MMCRA,
> - PERF_REG_POWERPC_MAX,
> + /* Extended registers */
> + PERF_REG_POWERPC_MMCR0,
> + PERF_REG_POWERPC_MMCR1,
> + PERF_REG_POWERPC_MMCR2,
> + /* Max regs without the extended regs */
> + PERF_REG_POWERPC_MAX = PERF_REG_POWERPC_MMCRA + 1,
> };
> +
> +#define PERF_REG_PMU_MASK ((1ULL << PERF_REG_POWERPC_MAX) - 1)
> +
> +/* PERF_REG_EXTENDED_MASK value for CPU_FTR_ARCH_300 */
> +#define PERF_REG_PMU_MASK_300 (((1ULL << (PERF_REG_POWERPC_MMCR2 + 1)) - 1) \
> + - PERF_REG_PMU_MASK)
> +
> #endif /* _UAPI_ASM_POWERPC_PERF_REGS_H */
> diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
> index 3dcfecf..f56b778 100644
> --- a/arch/powerpc/perf/core-book3s.c
> +++ b/arch/powerpc/perf/core-book3s.c
> @@ -2276,6 +2276,7 @@ int register_power_pmu(struct power_pmu *pmu)
>
> power_pmu.attr_groups = ppmu->attr_groups;
>
> + power_pmu.capabilities |= (ppmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS);
Could remove the newline above this statement and have newline
after this

> #ifdef MSR_HV
> /*
> * Use FCHV to ignore kernel events if MSR.HV is set.
> diff --git a/arch/powerpc/perf/perf_regs.c b/arch/powerpc/perf/perf_regs.c
> index a213a0a..f1dbbc5 100644
> --- a/arch/powerpc/perf/perf_regs.c
> +++ b/arch/powerpc/perf/perf_regs.c
> @@ -13,9 +13,11 @@
> #include <asm/ptrace.h>
> #include <asm/perf_regs.h>
>
> +u64 mask_var;
> +
> #define PT_REGS_OFFSET(id, r) [id] = offsetof(struct pt_regs, r)
>
> -#define REG_RESERVED (~((1ULL << PERF_REG_POWERPC_MAX) - 1))
> +#define REG_RESERVED (~(PERF_REG_EXTENDED_MASK | PERF_REG_PMU_MASK))
>
> static unsigned int pt_regs_offset[PERF_REG_POWERPC_MAX] = {
> PT_REGS_OFFSET(PERF_REG_POWERPC_R0, gpr[0]),
> @@ -69,10 +71,26 @@
> PT_REGS_OFFSET(PERF_REG_POWERPC_MMCRA, dsisr),
> };
>
> +/* Function to return the extended register values */
> +static u64 get_ext_regs_value(int idx)
> +{
> + switch (idx) {
> + case PERF_REG_POWERPC_MMCR0:
> + return mfspr(SPRN_MMCR0);
> + case PERF_REG_POWERPC_MMCR1:
> + return mfspr(SPRN_MMCR1);
> + case PERF_REG_POWERPC_MMCR2:
> + return mfspr(SPRN_MMCR2);

Why 3 tabs?

> + default: return 0;
> + }
> +}
> +
> u64 perf_reg_value(struct pt_regs *regs, int idx)
> {
> - if (WARN_ON_ONCE(idx >= PERF_REG_POWERPC_MAX))
> - return 0;
> + u64 PERF_REG_EXTENDED_MAX;
> +
> + if (cpu_has_feature(CPU_FTR_ARCH_300))
> + PERF_REG_EXTENDED_MAX = PERF_REG_POWERPC_MMCR2 + 1;
>
> if (idx == PERF_REG_POWERPC_SIER &&
> (IS_ENABLED(CONFIG_FSL_EMB_PERF_EVENT) ||
> @@ -85,6 +103,16 @@ u64 perf_reg_value(struct pt_regs *regs, int idx)
> IS_ENABLED(CONFIG_PPC32)))
> return 0;
>
> + if (idx >= PERF_REG_POWERPC_MAX && idx < PERF_REG_EXTENDED_MAX)
> + return get_ext_regs_value(idx);
> +
> + /*
> + * If the idx is referring to value beyond the
> + * supported registers, return 0 with a warning
> + */
> + if (WARN_ON_ONCE(idx >= PERF_REG_EXTENDED_MAX))
> + return 0;
> +
> return regs_get_register(regs, pt_regs_offset[idx]);
> }
>
> diff --git a/arch/powerpc/perf/power9-pmu.c b/arch/powerpc/perf/power9-pmu.c
> index 08c3ef7..4525090 100644
> --- a/arch/powerpc/perf/power9-pmu.c
> +++ b/arch/powerpc/perf/power9-pmu.c
> @@ -90,6 +90,8 @@ enum {
> #define POWER9_MMCRA_IFM3 0x00000000C0000000UL
> #define POWER9_MMCRA_BHRB_MASK 0x00000000C0000000UL
>
> +extern u64 mask_var;
> +
> /* Nasty Power9 specific hack */
> #define PVR_POWER9_CUMULUS 0x00002000
>
> @@ -434,6 +436,7 @@ static void power9_config_bhrb(u64 pmu_bhrb_filter)
> .cache_events = &power9_cache_events,
> .attr_groups = power9_pmu_attr_groups,
> .bhrb_nr = 32,
> + .capabilities = PERF_PMU_CAP_EXTENDED_REGS,
> };
>
> int init_power9_pmu(void)
> @@ -457,6 +460,9 @@ int init_power9_pmu(void)
> }
> }
>
> + /* Set the PERF_REG_EXTENDED_MASK here */
> + mask_var = PERF_REG_PMU_MASK_300;
> +
> rc = register_power_pmu(&power9_pmu);
> if (rc)
> return rc;

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