diff options
Diffstat (limited to 'arch/powerpc/perf/8xx-pmu.c')
| -rw-r--r-- | arch/powerpc/perf/8xx-pmu.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/arch/powerpc/perf/8xx-pmu.c b/arch/powerpc/perf/8xx-pmu.c new file mode 100644 index 000000000..308a2e40d --- /dev/null +++ b/arch/powerpc/perf/8xx-pmu.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Performance event support - PPC 8xx + * + * Copyright 2016 Christophe Leroy, CS Systemes d'Information + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/perf_event.h> +#include <linux/percpu.h> +#include <linux/hardirq.h> +#include <asm/pmc.h> +#include <asm/machdep.h> +#include <asm/firmware.h> +#include <asm/ptrace.h> +#include <asm/code-patching.h> +#include <asm/inst.h> + +#define PERF_8xx_ID_CPU_CYCLES 1 +#define PERF_8xx_ID_HW_INSTRUCTIONS 2 +#define PERF_8xx_ID_ITLB_LOAD_MISS 3 +#define PERF_8xx_ID_DTLB_LOAD_MISS 4 + +#define C(x) PERF_COUNT_HW_CACHE_##x +#define DTLB_LOAD_MISS (C(DTLB) | (C(OP_READ) << 8) | (C(RESULT_MISS) << 16)) +#define ITLB_LOAD_MISS (C(ITLB) | (C(OP_READ) << 8) | (C(RESULT_MISS) << 16)) + +extern unsigned long itlb_miss_counter, dtlb_miss_counter; +extern atomic_t instruction_counter; + +static atomic_t insn_ctr_ref; +static atomic_t itlb_miss_ref; +static atomic_t dtlb_miss_ref; + +static s64 get_insn_ctr(void) +{ + int ctr; + unsigned long counta; + + do { + ctr = atomic_read(&instruction_counter); + counta = mfspr(SPRN_COUNTA); + } while (ctr != atomic_read(&instruction_counter)); + + return ((s64)ctr << 16) | (counta >> 16); +} + +static int event_type(struct perf_event *event) +{ + switch (event->attr.type) { + case PERF_TYPE_HARDWARE: + if (event->attr.config == PERF_COUNT_HW_CPU_CYCLES) + return PERF_8xx_ID_CPU_CYCLES; + if (event->attr.config == PERF_COUNT_HW_INSTRUCTIONS) + return PERF_8xx_ID_HW_INSTRUCTIONS; + break; + case PERF_TYPE_HW_CACHE: + if (event->attr.config == ITLB_LOAD_MISS) + return PERF_8xx_ID_ITLB_LOAD_MISS; + if (event->attr.config == DTLB_LOAD_MISS) + return PERF_8xx_ID_DTLB_LOAD_MISS; + break; + case PERF_TYPE_RAW: + break; + default: + return -ENOENT; + } + return -EOPNOTSUPP; +} + +static int mpc8xx_pmu_event_init(struct perf_event *event) +{ + int type = event_type(event); + + if (type < 0) + return type; + return 0; +} + +static int mpc8xx_pmu_add(struct perf_event *event, int flags) +{ + int type = event_type(event); + s64 val = 0; + + if (type < 0) + return type; + + switch (type) { + case PERF_8xx_ID_CPU_CYCLES: + val = get_tb(); + break; + case PERF_8xx_ID_HW_INSTRUCTIONS: + if (atomic_inc_return(&insn_ctr_ref) == 1) + mtspr(SPRN_ICTRL, 0xc0080007); + val = get_insn_ctr(); + break; + case PERF_8xx_ID_ITLB_LOAD_MISS: + if (atomic_inc_return(&itlb_miss_ref) == 1) { + unsigned long target = patch_site_addr(&patch__itlbmiss_perf); + + patch_branch_site(&patch__itlbmiss_exit_1, target, 0); + } + val = itlb_miss_counter; + break; + case PERF_8xx_ID_DTLB_LOAD_MISS: + if (atomic_inc_return(&dtlb_miss_ref) == 1) { + unsigned long target = patch_site_addr(&patch__dtlbmiss_perf); + + patch_branch_site(&patch__dtlbmiss_exit_1, target, 0); + } + val = dtlb_miss_counter; + break; + } + local64_set(&event->hw.prev_count, val); + return 0; +} + +static void mpc8xx_pmu_read(struct perf_event *event) +{ + int type = event_type(event); + s64 prev, val = 0, delta = 0; + + if (type < 0) + return; + + do { + prev = local64_read(&event->hw.prev_count); + switch (type) { + case PERF_8xx_ID_CPU_CYCLES: + val = get_tb(); + delta = 16 * (val - prev); + break; + case PERF_8xx_ID_HW_INSTRUCTIONS: + val = get_insn_ctr(); + delta = prev - val; + if (delta < 0) + delta += 0x1000000000000LL; + break; + case PERF_8xx_ID_ITLB_LOAD_MISS: + val = itlb_miss_counter; + delta = (s64)((s32)val - (s32)prev); + break; + case PERF_8xx_ID_DTLB_LOAD_MISS: + val = dtlb_miss_counter; + delta = (s64)((s32)val - (s32)prev); + break; + } + } while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev); + + local64_add(delta, &event->count); +} + +static void mpc8xx_pmu_del(struct perf_event *event, int flags) +{ + ppc_inst_t insn = ppc_inst(PPC_RAW_MFSPR(10, SPRN_SPRG_SCRATCH2)); + + mpc8xx_pmu_read(event); + + /* If it was the last user, stop counting to avoid useless overhead */ + switch (event_type(event)) { + case PERF_8xx_ID_CPU_CYCLES: + break; + case PERF_8xx_ID_HW_INSTRUCTIONS: + if (atomic_dec_return(&insn_ctr_ref) == 0) + mtspr(SPRN_ICTRL, 7); + break; + case PERF_8xx_ID_ITLB_LOAD_MISS: + if (atomic_dec_return(&itlb_miss_ref) == 0) + patch_instruction_site(&patch__itlbmiss_exit_1, insn); + break; + case PERF_8xx_ID_DTLB_LOAD_MISS: + if (atomic_dec_return(&dtlb_miss_ref) == 0) + patch_instruction_site(&patch__dtlbmiss_exit_1, insn); + break; + } +} + +static struct pmu mpc8xx_pmu = { + .event_init = mpc8xx_pmu_event_init, + .add = mpc8xx_pmu_add, + .del = mpc8xx_pmu_del, + .read = mpc8xx_pmu_read, + .capabilities = PERF_PMU_CAP_NO_INTERRUPT | + PERF_PMU_CAP_NO_NMI, +}; + +static int init_mpc8xx_pmu(void) +{ + mtspr(SPRN_ICTRL, 7); + mtspr(SPRN_CMPA, 0); + mtspr(SPRN_COUNTA, 0xffff); + + return perf_pmu_register(&mpc8xx_pmu, "cpu", PERF_TYPE_RAW); +} + +early_initcall(init_mpc8xx_pmu); |