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-rw-r--r--arch/powerpc/perf/8xx-pmu.c197
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);