[PATCH] powerpc/perf: Power8 PMU support
From: Michael Ellerman
Date: Mon Apr 15 2013 - 00:17:45 EST
This patch adds preliminary support for the power8 PMU to perf.
Signed-off-by: Michael Ellerman <michael@xxxxxxxxxxxxxx>
---
arch/powerpc/perf/Makefile | 3 +-
arch/powerpc/perf/power8-pmu.c | 454 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 456 insertions(+), 1 deletion(-)
create mode 100644 arch/powerpc/perf/power8-pmu.c
diff --git a/arch/powerpc/perf/Makefile b/arch/powerpc/perf/Makefile
index af3fac2..472db18 100644
--- a/arch/powerpc/perf/Makefile
+++ b/arch/powerpc/perf/Makefile
@@ -4,7 +4,8 @@ obj-$(CONFIG_PERF_EVENTS) += callchain.o
obj-$(CONFIG_PPC_PERF_CTRS) += core-book3s.o
obj64-$(CONFIG_PPC_PERF_CTRS) += power4-pmu.o ppc970-pmu.o power5-pmu.o \
- power5+-pmu.o power6-pmu.o power7-pmu.o
+ power5+-pmu.o power6-pmu.o power7-pmu.o \
+ power8-pmu.o
obj32-$(CONFIG_PPC_PERF_CTRS) += mpc7450-pmu.o
obj-$(CONFIG_FSL_EMB_PERF_EVENT) += core-fsl-emb.o
diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c
new file mode 100644
index 0000000..106ae0b
--- /dev/null
+++ b/arch/powerpc/perf/power8-pmu.c
@@ -0,0 +1,454 @@
+/*
+ * Performance counter support for POWER8 processors.
+ *
+ * Copyright 2009 Paul Mackerras, IBM Corporation.
+ * Copyright 2013 Michael Ellerman, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/perf_event.h>
+#include <asm/firmware.h>
+
+
+/*
+ * Some power8 event codes.
+ */
+#define PM_CYC 0x0001e
+#define PM_GCT_NOSLOT_CYC 0x100f8
+#define PM_CMPLU_STALL 0x4000a /* or 0x1e054 */
+#define PM_INST_CMPL 0x00002
+#define PM_BRU_FIN 0x10068
+#define PM_BR_MPRED_CMPL 0x400f6
+
+
+/*
+ * Raw event encoding for POWER8:
+ *
+ * 60 56 52 48 44 40 36 32
+ * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - |
+ * [ thresh_cmp ] [ thresh_ctl ]
+ * |
+ * thresh start/stop OR FAB match -*
+ *
+ * 28 24 20 16 12 8 4 0
+ * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - |
+ * [ ] [ sample ] [cache] [ pmc ] [unit ] c m [ pmcxsel ]
+ * | | | | |
+ * | | | | *- mark
+ * | | *- L1/L2/L3 cache_sel |
+ * | | |
+ * | *- sampling mode for marked events *- combine
+ * |
+ * *- thresh_sel
+ *
+ * Below uses IBM bit numbering.
+ *
+ * MMCR1[x:y] = unit (PMCxUNIT)
+ * MMCR1[x] = combine (PMCxCOMB)
+ *
+ * if pmc == 3 and unit == 0 and pmcxsel[0:6] == 0b0101011
+ * # PM_MRK_FAB_RSP_MATCH
+ * MMCR1[20:27] = thresh_ctl (FAB_CRESP_MATCH / FAB_TYPE_MATCH)
+ * else if pmc == 4 and unit == 0xf and pmcxsel[0:6] == 0b0101001
+ * # PM_MRK_FAB_RSP_MATCH_CYC
+ * MMCR1[20:27] = thresh_ctl (FAB_CRESP_MATCH / FAB_TYPE_MATCH)
+ * else
+ * MMCRA[48:55] = thresh_ctl (THRESH START/END)
+ *
+ * if thresh_sel:
+ * MMCRA[45:47] = thresh_sel
+ *
+ * if thresh_cmp:
+ * MMCRA[22:24] = thresh_cmp[0:2]
+ * MMCRA[25:31] = thresh_cmp[3:9]
+ *
+ * if unit == 6 or unit == 7
+ * MMCRC[53:55] = cache_sel[1:3] (L2EVENT_SEL)
+ * else if unit == 8 or unit == 9:
+ * if cache_sel[0] == 0: # L3 bank
+ * MMCRC[47:49] = cache_sel[1:3] (L3EVENT_SEL0)
+ * else if cache_sel[0] == 1:
+ * MMCRC[50:51] = cache_sel[2:3] (L3EVENT_SEL1)
+ * else if cache_sel[1]: # L1 event
+ * MMCR1[16] = cache_sel[2]
+Â* MMCR1[17] = cache_sel[3]
+ *
+ * if mark:
+ * MMCRA[63] = 1 (SAMPLE_ENABLE)
+ * MMCRA[57:59] = sample[0:2] (RAND_SAMP_ELIG)
+Â* MMCRA[61:62] = sample[3:4] (RAND_SAMP_MODE)
+ *
+ */
+
+#define EVENT_THR_CMP_SHIFT 40 /* Threshold CMP value */
+#define EVENT_THR_CMP_MASK 0x3ff
+#define EVENT_THR_CTL_SHIFT 32 /* Threshold control value (start/stop) */
+#define EVENT_THR_CTL_MASK 0xffull
+#define EVENT_THR_SEL_SHIFT 29 /* Threshold select value */
+#define EVENT_THR_SEL_MASK 0x7
+#define EVENT_THRESH_SHIFT 29 /* All threshold bits */
+#define EVENT_THRESH_MASK 0x1fffffull
+#define EVENT_SAMPLE_SHIFT 24 /* Sampling mode & eligibility */
+#define EVENT_SAMPLE_MASK 0x1f
+#define EVENT_CACHE_SEL_SHIFT 20 /* L2/L3 cache select */
+#define EVENT_CACHE_SEL_MASK 0xf
+#define EVENT_IS_L1 (4 << EVENT_CACHE_SEL_SHIFT)
+#define EVENT_PMC_SHIFT 16 /* PMC number (1-based) */
+#define EVENT_PMC_MASK 0xf
+#define EVENT_UNIT_SHIFT 12 /* Unit */
+#define EVENT_UNIT_MASK 0xf
+#define EVENT_COMBINE_SHIFT 11 /* Combine bit */
+#define EVENT_COMBINE_MASK 0x1
+#define EVENT_MARKED_SHIFT 8 /* Marked bit */
+#define EVENT_MARKED_MASK 0x1
+#define EVENT_IS_MARKED (EVENT_MARKED_MASK << EVENT_MARKED_SHIFT)
+#define EVENT_PSEL_MASK 0xff /* PMCxSEL value */
+
+/*
+ * Layout of constraint bits:
+ *
+ * 60 56 52 48 44 40 36 32
+ * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - |
+ * [ fab_match ] [ thresh_cmp ] [ thresh_ctl ] [ ]
+ * |
+ * thresh_sel -*
+ *
+ * 28 24 20 16 12 8 4 0
+ * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - |
+ * [ ] [ sample ] [ ] [6] [5] [4] [3] [2] [1]
+ * | |
+ * L1 I/D qualifier -* | Count of events for each PMC.
+ * | p1, p2, p3, p4, p5, p6.
+ * nc - number of counters -*
+ *
+ * The PMC fields P1..P6, and NC, are adder fields. As we accumulate constraints
+ * we want the low bit of each field to be added to any existing value.
+ *
+ * Everything else is a value field.
+ */
+
+#define CNST_FAB_MATCH_VAL(v) (((v) & EVENT_THR_CTL_MASK) << 56)
+#define CNST_FAB_MATCH_MASK CNST_FAB_MATCH_VAL(EVENT_THR_CTL_MASK)
+
+/* We just throw all the threshold bits into the constraint */
+#define CNST_THRESH_VAL(v) (((v) & EVENT_THRESH_MASK) << 32)
+#define CNST_THRESH_MASK CNST_THRESH_VAL(EVENT_THRESH_MASK)
+
+#define CNST_L1_QUAL_VAL(v) (((v) & 3) << 22)
+#define CNST_L1_QUAL_MASK CNST_L1_QUAL_VAL(3)
+
+#define CNST_SAMPLE_VAL(v) (((v) & EVENT_SAMPLE_MASK) << 16)
+#define CNST_SAMPLE_MASK CNST_SAMPLE_VAL(EVENT_SAMPLE_MASK)
+
+/*
+ * For NC we are counting up to 4 events. This requires three bits, and we need
+ * the fifth event to overflow and set the 4th bit. To achieve that we bias the
+ * fields by 3 in test_adder.
+ */
+#define CNST_NC_SHIFT 12
+#define CNST_NC_VAL (1 << CNST_NC_SHIFT)
+#define CNST_NC_MASK (8 << CNST_NC_SHIFT)
+#define POWER8_TEST_ADDER (3 << CNST_NC_SHIFT)
+
+/*
+ * For the per-PMC fields we have two bits. The low bit is added, so if two
+ * events ask for the same PMC the sum will overflow, setting the high bit,
+ * indicating an error. So our mask sets the high bit.
+ */
+#define CNST_PMC_SHIFT(pmc) ((pmc - 1) * 2)
+#define CNST_PMC_VAL(pmc) (1 << CNST_PMC_SHIFT(pmc))
+#define CNST_PMC_MASK(pmc) (2 << CNST_PMC_SHIFT(pmc))
+
+/* Our add_fields is defined as: */
+#define POWER8_ADD_FIELDS \
+ CNST_PMC_VAL(1) | CNST_PMC_VAL(2) | CNST_PMC_VAL(3) | \
+ CNST_PMC_VAL(4) | CNST_PMC_VAL(5) | CNST_PMC_VAL(6) | CNST_NC_VAL
+
+
+/* Bits in MMCR1 for POWER8 */
+#define MMCR1_UNIT_SHIFT(pmc) (60 - (4 * ((pmc) - 1)))
+#define MMCR1_COMBINE_SHIFT(pmc) (35 - ((pmc) - 1))
+#define MMCR1_PMCSEL_SHIFT(pmc) (24 - (((pmc) - 1)) * 8)
+#define MMCR1_DC_QUAL_SHIFT 47
+#define MMCR1_IC_QUAL_SHIFT 46
+
+/* Bits in MMCRA for POWER8 */
+#define MMCRA_SAMP_MODE_SHIFT 1
+#define MMCRA_SAMP_ELIG_SHIFT 4
+#define MMCRA_THR_CTL_SHIFT 8
+#define MMCRA_THR_SEL_SHIFT 16
+#define MMCRA_THR_CMP_SHIFT 32
+#define MMCRA_SDAR_MODE_TLB (1ull << 42)
+
+
+static inline bool event_is_fab_match(u64 event)
+{
+ /* Only check pmc, unit and pmcxsel, ignore the edge bit (0) */
+ event &= 0xff0fe;
+
+ /* PM_MRK_FAB_RSP_MATCH & PM_MRK_FAB_RSP_MATCH_CYC */
+ return (event == 0x30056 || event == 0x4f052);
+}
+
+static int power8_get_constraint(u64 event, unsigned long *maskp, unsigned long *valp)
+{
+ unsigned int unit, pmc, cache;
+ unsigned long mask, value;
+
+ mask = value = 0;
+
+ pmc = (event >> EVENT_PMC_SHIFT) & EVENT_PMC_MASK;
+ unit = (event >> EVENT_UNIT_SHIFT) & EVENT_UNIT_MASK;
+ cache = (event >> EVENT_CACHE_SEL_SHIFT) & EVENT_CACHE_SEL_MASK;
+
+ if (pmc) {
+ if (pmc > 6)
+ return -1;
+
+ mask |= CNST_PMC_MASK(pmc);
+ value |= CNST_PMC_VAL(pmc);
+
+ if (pmc >= 5 && event != 0x500fa && event != 0x600f4)
+ return -1;
+ }
+
+ if (pmc <= 4) {
+ /*
+ * Add to number of counters in use. Note this includes events with
+ * a PMC of 0 - they still need a PMC, it's just assigned later.
+ * Don't count events on PMC 5 & 6, there is only one valid event
+ * on each of those counters, and they are handled above.
+ */
+ mask |= CNST_NC_MASK;
+ value |= CNST_NC_VAL;
+ }
+
+ if (unit >= 6 && unit <= 9) {
+ /*
+ * L2/L3 events contain a cache selector field, which is
+ * supposed to be programmed into MMCRC. However MMCRC is only
+ * HV writable, and there is no API for guest kernels to modify
+ * it. The solution is for the hypervisor to initialise the
+ * field to zeroes, and for us to only ever allow events that
+ * have a cache selector of zero.
+ */
+ if (cache)
+ return -1;
+
+ } else if (event & EVENT_IS_L1) {
+ mask |= CNST_L1_QUAL_MASK;
+ value |= CNST_L1_QUAL_VAL(cache);
+ }
+
+ if (event & EVENT_IS_MARKED) {
+ mask |= CNST_SAMPLE_MASK;
+ value |= CNST_SAMPLE_VAL(event >> EVENT_SAMPLE_SHIFT);
+ }
+
+ /*
+ * Special case for PM_MRK_FAB_RSP_MATCH and PM_MRK_FAB_RSP_MATCH_CYC,
+ * the threshold control bits are used for the match value.
+ */
+ if (event_is_fab_match(event)) {
+ mask |= CNST_FAB_MATCH_MASK;
+ value |= CNST_FAB_MATCH_VAL(event >> EVENT_THR_CTL_SHIFT);
+ } else {
+ /*
+ * Check the mantissa upper two bits are not zero, unless the
+ * exponent is also zero. See the THRESH_CMP_MANTISSA doc.
+ */
+ unsigned int cmp, exp;
+
+ cmp = (event >> EVENT_THR_CMP_SHIFT) & EVENT_THR_CMP_MASK;
+ exp = cmp >> 7;
+
+ if (exp && (cmp & 0x60) == 0)
+ return -1;
+
+ mask |= CNST_THRESH_MASK;
+ value |= CNST_THRESH_VAL(event >> EVENT_THRESH_SHIFT);
+ }
+
+ *maskp = mask;
+ *valp = value;
+
+ return 0;
+}
+
+static int power8_compute_mmcr(u64 event[], int n_ev,
+ unsigned int hwc[], unsigned long mmcr[])
+{
+ unsigned long mmcra, mmcr1, unit, combine, psel, cache, val;
+ unsigned int pmc, pmc_inuse;
+ int i;
+
+ pmc_inuse = 0;
+
+ /* First pass to count resource use */
+ for (i = 0; i < n_ev; ++i) {
+ pmc = (event[i] >> EVENT_PMC_SHIFT) & EVENT_PMC_MASK;
+ if (pmc)
+ pmc_inuse |= 1 << pmc;
+ }
+
+ /* In continous sampling mode, update SDAR on TLB miss */
+ mmcra = MMCRA_SDAR_MODE_TLB;
+ mmcr1 = 0;
+
+ /* Second pass: assign PMCs, set all MMCR1 fields */
+ for (i = 0; i < n_ev; ++i) {
+ pmc = (event[i] >> EVENT_PMC_SHIFT) & EVENT_PMC_MASK;
+ unit = (event[i] >> EVENT_UNIT_SHIFT) & EVENT_UNIT_MASK;
+ combine = (event[i] >> EVENT_COMBINE_SHIFT) & EVENT_COMBINE_MASK;
+ psel = event[i] & EVENT_PSEL_MASK;
+
+ if (!pmc) {
+ for (pmc = 1; pmc <= 4; ++pmc) {
+ if (!(pmc_inuse & (1 << pmc)))
+ break;
+ }
+
+ pmc_inuse |= 1 << pmc;
+ }
+
+ if (pmc <= 4) {
+ mmcr1 |= unit << MMCR1_UNIT_SHIFT(pmc);
+ mmcr1 |= combine << MMCR1_COMBINE_SHIFT(pmc);
+ mmcr1 |= psel << MMCR1_PMCSEL_SHIFT(pmc);
+ }
+
+ if (event[i] & EVENT_IS_L1) {
+ cache = event[i] >> EVENT_CACHE_SEL_SHIFT;
+ mmcr1 |= (cache & 1) << MMCR1_IC_QUAL_SHIFT;
+ cache >>= 1;
+ mmcr1 |= (cache & 1) << MMCR1_DC_QUAL_SHIFT;
+ }
+
+ if (event[i] & EVENT_IS_MARKED) {
+ mmcra |= MMCRA_SAMPLE_ENABLE;
+
+ val = (event[i] >> EVENT_SAMPLE_SHIFT) & EVENT_SAMPLE_MASK;
+ if (val) {
+ mmcra |= (val & 3) << MMCRA_SAMP_MODE_SHIFT;
+ mmcra |= (val >> 2) << MMCRA_SAMP_ELIG_SHIFT;
+ }
+ }
+
+ /*
+ * PM_MRK_FAB_RSP_MATCH and PM_MRK_FAB_RSP_MATCH_CYC,
+ * the threshold bits are used for the match value.
+ */
+ if (event_is_fab_match(event[i])) {
+ mmcr1 |= (event[i] >> EVENT_THR_CTL_SHIFT) &
+ EVENT_THR_CTL_MASK;
+ } else {
+ val = (event[i] >> EVENT_THR_CTL_SHIFT) & EVENT_THR_CTL_MASK;
+ mmcra |= val << MMCRA_THR_CTL_SHIFT;
+ val = (event[i] >> EVENT_THR_SEL_SHIFT) & EVENT_THR_SEL_MASK;
+ mmcra |= val << MMCRA_THR_SEL_SHIFT;
+ val = (event[i] >> EVENT_THR_CMP_SHIFT) & EVENT_THR_CMP_MASK;
+ mmcra |= val << MMCRA_THR_CMP_SHIFT;
+ }
+
+ hwc[i] = pmc - 1;
+ }
+
+ /* Return MMCRx values */
+ mmcr[0] = 0;
+
+ /* pmc_inuse is 1-based */
+ if (pmc_inuse & 2)
+ mmcr[0] = MMCR0_PMC1CE;
+
+ if (pmc_inuse & 0x7c)
+ mmcr[0] |= MMCR0_PMCjCE;
+
+ mmcr[1] = mmcr1;
+ mmcr[2] = mmcra;
+
+ return 0;
+}
+
+static void power8_disable_pmc(unsigned int pmc, unsigned long mmcr[])
+{
+ if (pmc <= 3)
+ mmcr[1] &= ~(0xffUL << MMCR1_PMCSEL_SHIFT(pmc + 1));
+}
+
+PMU_FORMAT_ATTR(event, "config:0-49");
+PMU_FORMAT_ATTR(pmcxsel, "config:0-7");
+PMU_FORMAT_ATTR(mark, "config:8");
+PMU_FORMAT_ATTR(combine, "config:11");
+PMU_FORMAT_ATTR(unit, "config:12-15");
+PMU_FORMAT_ATTR(pmc, "config:16-19");
+PMU_FORMAT_ATTR(cache_sel, "config:20-23");
+PMU_FORMAT_ATTR(sample_mode, "config:24-28");
+PMU_FORMAT_ATTR(thresh_sel, "config:29-31");
+PMU_FORMAT_ATTR(thresh_stop, "config:32-35");
+PMU_FORMAT_ATTR(thresh_start, "config:36-39");
+PMU_FORMAT_ATTR(thresh_cmp, "config:40-49");
+
+static struct attribute *power8_pmu_format_attr[] = {
+ &format_attr_event.attr,
+ &format_attr_pmcxsel.attr,
+ &format_attr_mark.attr,
+ &format_attr_combine.attr,
+ &format_attr_unit.attr,
+ &format_attr_pmc.attr,
+ &format_attr_cache_sel.attr,
+ &format_attr_sample_mode.attr,
+ &format_attr_thresh_sel.attr,
+ &format_attr_thresh_stop.attr,
+ &format_attr_thresh_start.attr,
+ &format_attr_thresh_cmp.attr,
+ NULL,
+};
+
+struct attribute_group power8_pmu_format_group = {
+ .name = "format",
+ .attrs = power8_pmu_format_attr,
+};
+
+static const struct attribute_group *power8_pmu_attr_groups[] = {
+ &power8_pmu_format_group,
+ NULL,
+};
+
+static int power8_generic_events[] = {
+ [PERF_COUNT_HW_CPU_CYCLES] = PM_CYC,
+ [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = PM_GCT_NOSLOT_CYC,
+ [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = PM_CMPLU_STALL,
+ [PERF_COUNT_HW_INSTRUCTIONS] = PM_INST_CMPL,
+ [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = PM_BRU_FIN,
+ [PERF_COUNT_HW_BRANCH_MISSES] = PM_BR_MPRED_CMPL,
+};
+
+static struct power_pmu power8_pmu = {
+ .name = "POWER8",
+ .n_counter = 6,
+ .max_alternatives = 0,
+ .add_fields = POWER8_ADD_FIELDS,
+ .test_adder = POWER8_TEST_ADDER,
+ .compute_mmcr = power8_compute_mmcr,
+ .get_constraint = power8_get_constraint,
+ .disable_pmc = power8_disable_pmc,
+ .flags = PPMU_HAS_SSLOT | PPMU_HAS_SIER,
+ .n_generic = ARRAY_SIZE(power8_generic_events),
+ .generic_events = power8_generic_events,
+ .attr_groups = power8_pmu_attr_groups,
+};
+
+static int __init init_power8_pmu(void)
+{
+ if (!cur_cpu_spec->oprofile_cpu_type ||
+ strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power8"))
+ return -ENODEV;
+
+ return register_power_pmu(&power8_pmu);
+}
+early_initcall(init_power8_pmu);
--
1.7.10.4
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