[tip:branch?] perf_counters: powerpc: Add support for POWER7 processors

tip-bot for Paul Mackerras
2009-06-11T10:10:20Z

Commit-ID: 526e9a09d2e2dcb6c75c68710465678bb647e5fe
Gitweb: http://git.kernel.org/tip/526e9a09d2e2dcb6c75c68710465678bb647e5fe
Author: Paul Mackerras <paulus@samba.org>
AuthorDate: Thu, 11 Jun 2009 14:54:01 +1000
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 11 Jun 2009 12:07:37 +0200

perf_counters: powerpc: Add support for POWER7 processors

This adds the back-end for the PMU on POWER7 processors. POWER7
has 4 fully-programmable counters and two fixed-function counters
(which do respect the freeze conditions, can generate interrupts,
and are writable, unlike PMC5/6 on POWER5+/6).

Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <18992.36329.189378.17992@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
arch/powerpc/kernel/Makefile | 3 +-
arch/powerpc/kernel/perf_counter.c | 4 +
arch/powerpc/kernel/power7-pmu.c | 316 ++++++++++++++++++++++++++++++++++++
3 files changed, 322 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 9ba1bb7..a2c6834 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -95,7 +95,8 @@ obj64-$(CONFIG_AUDIT) += compat_audit.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o power4-pmu.o ppc970-pmu.o \
- power5-pmu.o power5+-pmu.o power6-pmu.o
+ power5-pmu.o power5+-pmu.o power6-pmu.o \
+ power7-pmu.o

obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o

diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c
index 4990ce2..5d12e68 100644
--- a/arch/powerpc/kernel/perf_counter.c
+++ b/arch/powerpc/kernel/perf_counter.c
@@ -1181,6 +1181,7 @@ extern struct power_pmu ppc970_pmu;
extern struct power_pmu power5_pmu;
extern struct power_pmu power5p_pmu;
extern struct power_pmu power6_pmu;
+extern struct power_pmu power7_pmu;

static int init_perf_counters(void)
{
@@ -1207,6 +1208,9 @@ static int init_perf_counters(void)
case 0x3e:
ppmu = &power6_pmu;
break;
+ case 0x3f:
+ ppmu = &power7_pmu;
+ break;
}

/*
diff --git a/arch/powerpc/kernel/power7-pmu.c b/arch/powerpc/kernel/power7-pmu.c
new file mode 100644
index 0000000..dfac48d
--- /dev/null
+++ b/arch/powerpc/kernel/power7-pmu.c
@@ -0,0 +1,316 @@
+/*
+ * Performance counter support for POWER7 processors.
+ *
+ * Copyright 2009 Paul Mackerras, 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_counter.h>
+#include <asm/reg.h>
+
+/*
+ * Bits in event code for POWER7
+ */
+#define PM_PMC_SH 16 /* PMC number (1-based) for direct events */
+#define PM_PMC_MSK 0xf
+#define PM_PMC_MSKS (PM_PMC_MSK << PM_PMC_SH)
+#define PM_UNIT_SH 12 /* TTMMUX number and setting - unit select */
+#define PM_UNIT_MSK 0xf
+#define PM_COMBINE_SH 11 /* Combined event bit */
+#define PM_COMBINE_MSK 1
+#define PM_COMBINE_MSKS 0x800
+#define PM_L2SEL_SH 8 /* L2 event select */
+#define PM_L2SEL_MSK 7
+#define PM_PMCSEL_MSK 0xff
+
+/*
+ * Bits in MMCR1 for POWER7
+ */
+#define MMCR1_TTM0SEL_SH 60
+#define MMCR1_TTM1SEL_SH 56
+#define MMCR1_TTM2SEL_SH 52
+#define MMCR1_TTM3SEL_SH 48
+#define MMCR1_TTMSEL_MSK 0xf
+#define MMCR1_L2SEL_SH 45
+#define MMCR1_L2SEL_MSK 7
+#define MMCR1_PMC1_COMBINE_SH 35
+#define MMCR1_PMC2_COMBINE_SH 34
+#define MMCR1_PMC3_COMBINE_SH 33
+#define MMCR1_PMC4_COMBINE_SH 32
+#define MMCR1_PMC1SEL_SH 24
+#define MMCR1_PMC2SEL_SH 16
+#define MMCR1_PMC3SEL_SH 8
+#define MMCR1_PMC4SEL_SH 0
+#define MMCR1_PMCSEL_SH(n) (MMCR1_PMC1SEL_SH - (n) * 8)
+#define MMCR1_PMCSEL_MSK 0xff
+
+/*
+ * Bits in MMCRA
+ */
+
+/*
+ * Layout of constraint bits:
+ * 6666555555555544444444443333333333222222222211111111110000000000
+ * 3210987654321098765432109876543210987654321098765432109876543210
+ * [ ><><><><><><>
+ * NC P6P5P4P3P2P1
+ *
+ * NC - number of counters
+ * 15: NC error 0x8000
+ * 12-14: number of events needing PMC1-4 0x7000
+ *
+ * P6
+ * 11: P6 error 0x800
+ * 10-11: Count of events needing PMC6
+ *
+ * P1..P5
+ * 0-9: Count of events needing PMC1..PMC5
+ */
+
+static int power7_get_constraint(u64 event, u64 *maskp, u64 *valp)
+{
+ int pmc, sh;
+ u64 mask = 0, value = 0;
+
+ pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
+ if (pmc) {
+ if (pmc > 6)
+ return -1;
+ sh = (pmc - 1) * 2;
+ mask |= 2 << sh;
+ value |= 1 << sh;
+ if (pmc >= 5 && !(event == 0x500fa || event == 0x600f4))
+ return -1;
+ }
+ if (pmc < 5) {
+ /* need a counter from PMC1-4 set */
+ mask |= 0x8000;
+ value |= 0x1000;
+ }
+ *maskp = mask;
+ *valp = value;
+ return 0;
+}
+
+#define MAX_ALT 2 /* at most 2 alternatives for any event */
+
+static const unsigned int event_alternatives[][MAX_ALT] = {
+ { 0x200f2, 0x300f2 }, /* PM_INST_DISP */
+ { 0x200f4, 0x600f4 }, /* PM_RUN_CYC */
+ { 0x400fa, 0x500fa }, /* PM_RUN_INST_CMPL */
+};
+
+/*
+ * Scan the alternatives table for a match and return the
+ * index into the alternatives table if found, else -1.
+ */
+static int find_alternative(u64 event)
+{
+ int i, j;
+
+ for (i = 0; i < ARRAY_SIZE(event_alternatives); ++i) {
+ if (event < event_alternatives[i][0])
+ break;
+ for (j = 0; j < MAX_ALT && event_alternatives[i][j]; ++j)
+ if (event == event_alternatives[i][j])
+ return i;
+ }
+ return -1;
+}
+
+static s64 find_alternative_decode(u64 event)
+{
+ int pmc, psel;
+
+ /* this only handles the 4x decode events */
+ pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
+ psel = event & PM_PMCSEL_MSK;
+ if ((pmc == 2 || pmc == 4) && (psel & ~7) == 0x40)
+ return event - (1 << PM_PMC_SH) + 8;
+ if ((pmc == 1 || pmc == 3) && (psel & ~7) == 0x48)
+ return event + (1 << PM_PMC_SH) - 8;
+ return -1;
+}
+
+static int power7_get_alternatives(u64 event, unsigned int flags, u64 alt[])
+{
+ int i, j, nalt = 1;
+ s64 ae;
+
+ alt[0] = event;
+ nalt = 1;
+ i = find_alternative(event);
+ if (i >= 0) {
+ for (j = 0; j < MAX_ALT; ++j) {
+ ae = event_alternatives[i][j];
+ if (ae && ae != event)
+ alt[nalt++] = ae;
+ }
+ } else {
+ ae = find_alternative_decode(event);
+ if (ae > 0)
+ alt[nalt++] = ae;
+ }
+
+ if (flags & PPMU_ONLY_COUNT_RUN) {
+ /*
+ * We're only counting in RUN state,
+ * so PM_CYC is equivalent to PM_RUN_CYC
+ * and PM_INST_CMPL === PM_RUN_INST_CMPL.
+ * This doesn't include alternatives that don't provide
+ * any extra flexibility in assigning PMCs.
+ */
+ j = nalt;
+ for (i = 0; i < nalt; ++i) {
+ switch (alt[i]) {
+ case 0x1e: /* PM_CYC */
+ alt[j++] = 0x600f4; /* PM_RUN_CYC */
+ break;
+ case 0x600f4: /* PM_RUN_CYC */
+ alt[j++] = 0x1e;
+ break;
+ case 0x2: /* PM_PPC_CMPL */
+ alt[j++] = 0x500fa; /* PM_RUN_INST_CMPL */
+ break;
+ case 0x500fa: /* PM_RUN_INST_CMPL */
+ alt[j++] = 0x2; /* PM_PPC_CMPL */
+ break;
+ }
+ }
+ nalt = j;
+ }
+
+ return nalt;
+}
+
+/*
+ * Returns 1 if event counts things relating to marked instructions
+ * and thus needs the MMCRA_SAMPLE_ENABLE bit set, or 0 if not.
+ */
+static int power7_marked_instr_event(u64 event)
+{
+ int pmc, psel;
+ int unit;
+
+ pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
+ unit = (event >> PM_UNIT_SH) & PM_UNIT_MSK;
+ psel = event & PM_PMCSEL_MSK & ~1; /* trim off edge/level bit */
+ if (pmc >= 5)
+ return 0;
+
+ switch (psel >> 4) {
+ case 2:
+ return pmc == 2 || pmc == 4;
+ case 3:
+ if (psel == 0x3c)
+ return pmc == 1;
+ if (psel == 0x3e)
+ return pmc != 2;
+ return 1;
+ case 4:
+ case 5:
+ return unit == 0xd;
+ case 6:
+ if (psel == 0x64)
+ return pmc >= 3;
+ case 8:
+ return unit == 0xd;
+ }
+ return 0;
+}
+
+static int power7_compute_mmcr(u64 event[], int n_ev,
+ unsigned int hwc[], u64 mmcr[])
+{
+ u64 mmcr1 = 0;
+ u64 mmcra = 0;
+ unsigned int pmc, unit, combine, l2sel, psel;
+ unsigned int pmc_inuse = 0;
+ int i;
+
+ /* First pass to count resource use */
+ for (i = 0; i < n_ev; ++i) {
+ pmc = (event[i] >> PM_PMC_SH) & PM_PMC_MSK;
+ if (pmc) {
+ if (pmc > 6)
+ return -1;
+ if (pmc_inuse & (1 << (pmc - 1)))
+ return -1;
+ pmc_inuse |= 1 << (pmc - 1);
+ }
+ }
+
+ /* Second pass: assign PMCs, set all MMCR1 fields */
+ for (i = 0; i < n_ev; ++i) {
+ pmc = (event[i] >> PM_PMC_SH) & PM_PMC_MSK;
+ unit = (event[i] >> PM_UNIT_SH) & PM_UNIT_MSK;
+ combine = (event[i] >> PM_COMBINE_SH) & PM_COMBINE_MSK;
+ l2sel = (event[i] >> PM_L2SEL_SH) & PM_L2SEL_MSK;
+ psel = event[i] & PM_PMCSEL_MSK;
+ if (!pmc) {
+ /* Bus event or any-PMC direct event */
+ for (pmc = 0; pmc < 4; ++pmc) {
+ if (!(pmc_inuse & (1 << pmc)))
+ break;
+ }
+ if (pmc >= 4)
+ return -1;
+ pmc_inuse |= 1 << pmc;
+ } else {
+ /* Direct or decoded event */
+ --pmc;
+ }
+ if (pmc <= 3) {
+ mmcr1 |= (u64) unit << (MMCR1_TTM0SEL_SH - 4 * pmc);
+ mmcr1 |= (u64) combine << (MMCR1_PMC1_COMBINE_SH - pmc);
+ mmcr1 |= psel << MMCR1_PMCSEL_SH(pmc);
+ if (unit == 6) /* L2 events */
+ mmcr1 |= (u64) l2sel << MMCR1_L2SEL_SH;
+ }
+ if (power7_marked_instr_event(event[i]))
+ mmcra |= MMCRA_SAMPLE_ENABLE;
+ hwc[i] = pmc;
+ }
+
+ /* Return MMCRx values */
+ mmcr[0] = 0;
+ if (pmc_inuse & 1)
+ mmcr[0] = MMCR0_PMC1CE;
+ if (pmc_inuse & 0x3e)
+ mmcr[0] |= MMCR0_PMCjCE;
+ mmcr[1] = mmcr1;
+ mmcr[2] = mmcra;
+ return 0;
+}
+
+static void power7_disable_pmc(unsigned int pmc, u64 mmcr[])
+{
+ if (pmc <= 3)
+ mmcr[1] &= ~(0xffULL << MMCR1_PMCSEL_SH(pmc));
+}
+
+static int power7_generic_events[] = {
+ [PERF_COUNT_CPU_CYCLES] = 0x1e,
+ [PERF_COUNT_INSTRUCTIONS] = 2,
+ [PERF_COUNT_CACHE_REFERENCES] = 0xc880, /* LD_REF_L1_LSU */
+ [PERF_COUNT_CACHE_MISSES] = 0x400f0, /* LD_MISS_L1 */
+ [PERF_COUNT_BRANCH_INSTRUCTIONS] = 0x10068, /* BRU_FIN */
+ [PERF_COUNT_BRANCH_MISSES] = 0x400f6, /* BR_MPRED */
+};
+
+struct power_pmu power7_pmu = {
+ .n_counter = 6,
+ .max_alternatives = MAX_ALT + 1,
+ .add_fields = 0x1555ull,
+ .test_adder = 0x3000ull,
+ .compute_mmcr = power7_compute_mmcr,
+ .get_constraint = power7_get_constraint,
+ .get_alternatives = power7_get_alternatives,
+ .disable_pmc = power7_disable_pmc,
+ .n_generic = ARRAY_SIZE(power7_generic_events),
+ .generic_events = power7_generic_events,
+};