[PATCH] perfcounters/powerpc: Add support for POWER5 processors

From: Paul Mackerras
Date: Thu Feb 26 2009 - 00:12:28 EST


This adds the back-end for the PMU on the POWER5 processor. This knows
how to use the fixed-function PMC5 and PMC6 (instructions completed and
run cycles). Unlike POWER6, PMC5/6 obey the freeze conditions and can
generate interrupts, so their use doesn't impose any extra restrictions.

POWER5+ is different and is not supported by this patch.

Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
---
Ingo, please pull this from my perfcounters.git tree master branch at:

git://git.kernel.org/pub/scm/linux/kernel/git/paulus/perfcounters.git master

arch/powerpc/kernel/Makefile | 3 +-
arch/powerpc/kernel/perf_counter.c | 4 +
arch/powerpc/kernel/power5-pmu.c | 475 ++++++++++++++++++++++++++++++++++++
3 files changed, 481 insertions(+), 1 deletions(-)
create mode 100644 arch/powerpc/kernel/power5-pmu.c

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 7c941ec..b4c6f46 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -94,7 +94,8 @@ obj-$(CONFIG_AUDIT) += audit.o
obj64-$(CONFIG_AUDIT) += compat_audit.o

obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
-obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o ppc970-pmu.o power6-pmu.o
+obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o ppc970-pmu.o power5-pmu.o \
+ power6-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 6e27913..112332d 100644
--- a/arch/powerpc/kernel/perf_counter.c
+++ b/arch/powerpc/kernel/perf_counter.c
@@ -824,6 +824,7 @@ void hw_perf_counter_setup(int cpu)
}

extern struct power_pmu ppc970_pmu;
+extern struct power_pmu power5_pmu;
extern struct power_pmu power6_pmu;

static int init_perf_counters(void)
@@ -843,6 +844,9 @@ static int init_perf_counters(void)
case PV_970MP:
ppmu = &ppc970_pmu;
break;
+ case PV_POWER5:
+ ppmu = &power5_pmu;
+ break;
case 0x3e:
ppmu = &power6_pmu;
break;
diff --git a/arch/powerpc/kernel/power5-pmu.c b/arch/powerpc/kernel/power5-pmu.c
new file mode 100644
index 0000000..379ed10
--- /dev/null
+++ b/arch/powerpc/kernel/power5-pmu.c
@@ -0,0 +1,475 @@
+/*
+ * Performance counter support for POWER5 (not POWER5++) 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 POWER5 (not POWER5++)
+ */
+#define PM_PMC_SH 20 /* 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 16 /* TTMMUX number and setting - unit select */
+#define PM_UNIT_MSK 0xf
+#define PM_BYTE_SH 12 /* Byte number of event bus to use */
+#define PM_BYTE_MSK 7
+#define PM_GRS_SH 8 /* Storage subsystem mux select */
+#define PM_GRS_MSK 7
+#define PM_BUSEVENT_MSK 0x80 /* Set if event uses event bus */
+#define PM_PMCSEL_MSK 0x7f
+
+/* Values in PM_UNIT field */
+#define PM_FPU 0
+#define PM_ISU0 1
+#define PM_IFU 2
+#define PM_ISU1 3
+#define PM_IDU 4
+#define PM_ISU0_ALT 6
+#define PM_GRS 7
+#define PM_LSU0 8
+#define PM_LSU1 0xc
+#define PM_LASTUNIT 0xc
+
+/*
+ * Bits in MMCR1 for POWER5
+ */
+#define MMCR1_TTM0SEL_SH 62
+#define MMCR1_TTM1SEL_SH 60
+#define MMCR1_TTM2SEL_SH 58
+#define MMCR1_TTM3SEL_SH 56
+#define MMCR1_TTMSEL_MSK 3
+#define MMCR1_TD_CP_DBG0SEL_SH 54
+#define MMCR1_TD_CP_DBG1SEL_SH 52
+#define MMCR1_TD_CP_DBG2SEL_SH 50
+#define MMCR1_TD_CP_DBG3SEL_SH 48
+#define MMCR1_GRS_L2SEL_SH 46
+#define MMCR1_GRS_L2SEL_MSK 3
+#define MMCR1_GRS_L3SEL_SH 44
+#define MMCR1_GRS_L3SEL_MSK 3
+#define MMCR1_GRS_MCSEL_SH 41
+#define MMCR1_GRS_MCSEL_MSK 7
+#define MMCR1_GRS_FABSEL_SH 39
+#define MMCR1_GRS_FABSEL_MSK 3
+#define MMCR1_PMC1_ADDER_SEL_SH 35
+#define MMCR1_PMC2_ADDER_SEL_SH 34
+#define MMCR1_PMC3_ADDER_SEL_SH 33
+#define MMCR1_PMC4_ADDER_SEL_SH 32
+#define MMCR1_PMC1SEL_SH 25
+#define MMCR1_PMC2SEL_SH 17
+#define MMCR1_PMC3SEL_SH 9
+#define MMCR1_PMC4SEL_SH 1
+#define MMCR1_PMCSEL_SH(n) (MMCR1_PMC1SEL_SH - (n) * 8)
+#define MMCR1_PMCSEL_MSK 0x7f
+
+/*
+ * Bits in MMCRA
+ */
+
+/*
+ * Layout of constraint bits:
+ * 6666555555555544444444443333333333222222222211111111110000000000
+ * 3210987654321098765432109876543210987654321098765432109876543210
+ * <><>[ ><><>< ><> [ >[ >[ >< >< >< >< ><><><><><><>
+ * T0T1 NC G0G1G2 G3 UC PS1PS2 B0 B1 B2 B3 P6P5P4P3P2P1
+ *
+ * T0 - TTM0 constraint
+ * 54-55: TTM0SEL value (0=FPU, 2=IFU, 3=ISU1) 0xc0_0000_0000_0000
+ *
+ * T1 - TTM1 constraint
+ * 52-53: TTM1SEL value (0=IDU, 3=GRS) 0x30_0000_0000_0000
+ *
+ * NC - number of counters
+ * 51: NC error 0x0008_0000_0000_0000
+ * 48-50: number of events needing PMC1-4 0x0007_0000_0000_0000
+ *
+ * G0..G3 - GRS mux constraints
+ * 46-47: GRS_L2SEL value
+ * 44-45: GRS_L3SEL value
+ * 41-44: GRS_MCSEL value
+ * 39-40: GRS_FABSEL value
+ * Note that these match up with their bit positions in MMCR1
+ *
+ * UC - unit constraint: can't have all three of FPU|IFU|ISU1, ISU0, IDU|GRS
+ * 37: UC3 error 0x20_0000_0000
+ * 36: FPU|IFU|ISU1 events needed 0x10_0000_0000
+ * 35: ISU0 events needed 0x08_0000_0000
+ * 34: IDU|GRS events needed 0x04_0000_0000
+ *
+ * PS1
+ * 33: PS1 error 0x2_0000_0000
+ * 31-32: count of events needing PMC1/2 0x1_8000_0000
+ *
+ * PS2
+ * 30: PS2 error 0x4000_0000
+ * 28-29: count of events needing PMC3/4 0x3000_0000
+ *
+ * B0
+ * 24-27: Byte 0 event source 0x0f00_0000
+ * Encoding as for the event code
+ *
+ * B1, B2, B3
+ * 20-23, 16-19, 12-15: Byte 1, 2, 3 event sources
+ *
+ * P1..P6
+ * 0-11: Count of events needing PMC1..PMC6
+ */
+
+static const int grsel_shift[8] = {
+ MMCR1_GRS_L2SEL_SH, MMCR1_GRS_L2SEL_SH, MMCR1_GRS_L2SEL_SH,
+ MMCR1_GRS_L3SEL_SH, MMCR1_GRS_L3SEL_SH, MMCR1_GRS_L3SEL_SH,
+ MMCR1_GRS_MCSEL_SH, MMCR1_GRS_FABSEL_SH
+};
+
+/* Masks and values for using events from the various units */
+static u64 unit_cons[PM_LASTUNIT+1][2] = {
+ [PM_FPU] = { 0xc0002000000000ull, 0x00001000000000ull },
+ [PM_ISU0] = { 0x00002000000000ull, 0x00000800000000ull },
+ [PM_ISU1] = { 0xc0002000000000ull, 0xc0001000000000ull },
+ [PM_IFU] = { 0xc0002000000000ull, 0x80001000000000ull },
+ [PM_IDU] = { 0x30002000000000ull, 0x00000400000000ull },
+ [PM_GRS] = { 0x30002000000000ull, 0x30000400000000ull },
+};
+
+static int power5_get_constraint(unsigned int event, u64 *maskp, u64 *valp)
+{
+ int pmc, byte, unit, sh;
+ int bit, fmask;
+ u64 mask = 0, value = 0;
+ int grp = -1;
+
+ 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 <= 4)
+ grp = (pmc - 1) >> 1;
+ else if (event != 0x500009 && event != 0x600005)
+ return -1;
+ }
+ if (event & PM_BUSEVENT_MSK) {
+ unit = (event >> PM_UNIT_SH) & PM_UNIT_MSK;
+ if (unit > PM_LASTUNIT)
+ return -1;
+ if (unit == PM_ISU0_ALT)
+ unit = PM_ISU0;
+ mask |= unit_cons[unit][0];
+ value |= unit_cons[unit][1];
+ byte = (event >> PM_BYTE_SH) & PM_BYTE_MSK;
+ if (byte >= 4) {
+ if (unit != PM_LSU1)
+ return -1;
+ /* Map LSU1 low word (bytes 4-7) to unit LSU1+1 */
+ ++unit;
+ byte &= 3;
+ }
+ if (unit == PM_GRS) {
+ bit = event & 7;
+ fmask = (bit == 6)? 7: 3;
+ sh = grsel_shift[bit];
+ mask |= (u64)fmask << sh;
+ value |= (u64)((event >> PM_GRS_SH) & fmask) << sh;
+ }
+ /*
+ * Bus events on bytes 0 and 2 can be counted
+ * on PMC1/2; bytes 1 and 3 on PMC3/4.
+ */
+ if (!pmc)
+ grp = byte & 1;
+ /* Set byte lane select field */
+ mask |= 0xfULL << (24 - 4 * byte);
+ value |= (u64)unit << (24 - 4 * byte);
+ }
+ if (grp == 0) {
+ /* increment PMC1/2 field */
+ mask |= 0x200000000ull;
+ value |= 0x080000000ull;
+ } else if (grp == 1) {
+ /* increment PMC3/4 field */
+ mask |= 0x40000000ull;
+ value |= 0x10000000ull;
+ }
+ if (pmc < 5) {
+ /* need a counter from PMC1-4 set */
+ mask |= 0x8000000000000ull;
+ value |= 0x1000000000000ull;
+ }
+ *maskp = mask;
+ *valp = value;
+ return 0;
+}
+
+#define MAX_ALT 3 /* at most 3 alternatives for any event */
+
+static const unsigned int event_alternatives[][MAX_ALT] = {
+ { 0x120e4, 0x400002 }, /* PM_GRP_DISP_REJECT */
+ { 0x410c7, 0x441084 }, /* PM_THRD_L2MISS_BOTH_CYC */
+ { 0x100005, 0x600005 }, /* PM_RUN_CYC */
+ { 0x100009, 0x200009, 0x500009 }, /* PM_INST_CMPL */
+ { 0x300009, 0x400009 }, /* PM_INST_DISP */
+};
+
+/*
+ * Scan the alternatives table for a match and return the
+ * index into the alternatives table if found, else -1.
+ */
+static int find_alternative(unsigned int 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 const unsigned char bytedecode_alternatives[4][4] = {
+ /* PMC 1 */ { 0x21, 0x23, 0x25, 0x27 },
+ /* PMC 2 */ { 0x07, 0x17, 0x0e, 0x1e },
+ /* PMC 3 */ { 0x20, 0x22, 0x24, 0x26 },
+ /* PMC 4 */ { 0x07, 0x17, 0x0e, 0x1e }
+};
+
+/*
+ * Some direct events for decodes of event bus byte 3 have alternative
+ * PMCSEL values on other counters. This returns the alternative
+ * event code for those that do, or -1 otherwise.
+ */
+static int find_alternative_bdecode(unsigned int event)
+{
+ int pmc, altpmc, pp, j;
+
+ pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
+ if (pmc == 0 || pmc > 4)
+ return -1;
+ altpmc = 5 - pmc; /* 1 <-> 4, 2 <-> 3 */
+ pp = event & PM_PMCSEL_MSK;
+ for (j = 0; j < 4; ++j) {
+ if (bytedecode_alternatives[pmc - 1][j] == pp) {
+ return (event & ~(PM_PMC_MSKS | PM_PMCSEL_MSK)) |
+ (altpmc << PM_PMC_SH) |
+ bytedecode_alternatives[altpmc - 1][j];
+ }
+ }
+ return -1;
+}
+
+static int power5_get_alternatives(unsigned int event, unsigned int alt[])
+{
+ int i, j, ae, nalt = 1;
+
+ 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_bdecode(event);
+ if (ae > 0)
+ alt[nalt++] = ae;
+ }
+ return nalt;
+}
+
+static int power5_compute_mmcr(unsigned int event[], int n_ev,
+ unsigned int hwc[], u64 mmcr[])
+{
+ u64 mmcr1 = 0;
+ unsigned int pmc, unit, byte, psel;
+ unsigned int ttm, grp;
+ int i, isbus, bit, grsel;
+ unsigned int pmc_inuse = 0;
+ unsigned int pmc_grp_use[2];
+ unsigned char busbyte[4];
+ unsigned char unituse[16];
+ int ttmuse;
+
+ if (n_ev > 6)
+ return -1;
+
+ /* First pass to count resource use */
+ pmc_grp_use[0] = pmc_grp_use[1] = 0;
+ memset(busbyte, 0, sizeof(busbyte));
+ memset(unituse, 0, sizeof(unituse));
+ 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);
+ /* count 1/2 vs 3/4 use */
+ if (pmc <= 4)
+ ++pmc_grp_use[(pmc - 1) >> 1];
+ }
+ if (event[i] & PM_BUSEVENT_MSK) {
+ unit = (event[i] >> PM_UNIT_SH) & PM_UNIT_MSK;
+ byte = (event[i] >> PM_BYTE_SH) & PM_BYTE_MSK;
+ if (unit > PM_LASTUNIT)
+ return -1;
+ if (unit == PM_ISU0_ALT)
+ unit = PM_ISU0;
+ if (byte >= 4) {
+ if (unit != PM_LSU1)
+ return -1;
+ ++unit;
+ byte &= 3;
+ }
+ if (!pmc)
+ ++pmc_grp_use[byte & 1];
+ if (busbyte[byte] && busbyte[byte] != unit)
+ return -1;
+ busbyte[byte] = unit;
+ unituse[unit] = 1;
+ }
+ }
+ if (pmc_grp_use[0] > 2 || pmc_grp_use[1] > 2)
+ return -1;
+
+ /*
+ * Assign resources and set multiplexer selects.
+ *
+ * PM_ISU0 can go either on TTM0 or TTM1, but that's the only
+ * choice we have to deal with.
+ */
+ if (unituse[PM_ISU0] &
+ (unituse[PM_FPU] | unituse[PM_IFU] | unituse[PM_ISU1])) {
+ unituse[PM_ISU0_ALT] = 1; /* move ISU to TTM1 */
+ unituse[PM_ISU0] = 0;
+ }
+ /* Set TTM[01]SEL fields. */
+ ttmuse = 0;
+ for (i = PM_FPU; i <= PM_ISU1; ++i) {
+ if (!unituse[i])
+ continue;
+ if (ttmuse++)
+ return -1;
+ mmcr1 |= (u64)i << MMCR1_TTM0SEL_SH;
+ }
+ ttmuse = 0;
+ for (; i <= PM_GRS; ++i) {
+ if (!unituse[i])
+ continue;
+ if (ttmuse++)
+ return -1;
+ mmcr1 |= (u64)(i & 3) << MMCR1_TTM1SEL_SH;
+ }
+ if (ttmuse > 1)
+ return -1;
+
+ /* Set byte lane select fields, TTM[23]SEL and GRS_*SEL. */
+ for (byte = 0; byte < 4; ++byte) {
+ unit = busbyte[byte];
+ if (!unit)
+ continue;
+ if (unit == PM_ISU0 && unituse[PM_ISU0_ALT]) {
+ /* get ISU0 through TTM1 rather than TTM0 */
+ unit = PM_ISU0_ALT;
+ } else if (unit == PM_LSU1 + 1) {
+ /* select lower word of LSU1 for this byte */
+ mmcr1 |= 1ull << (MMCR1_TTM3SEL_SH + 3 - byte);
+ }
+ ttm = unit >> 2;
+ mmcr1 |= (u64)ttm << (MMCR1_TD_CP_DBG0SEL_SH - 2 * byte);
+ }
+
+ /* Second pass: assign PMCs, set PMCxSEL and PMCx_ADDER_SEL 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;
+ byte = (event[i] >> PM_BYTE_SH) & PM_BYTE_MSK;
+ psel = event[i] & PM_PMCSEL_MSK;
+ isbus = event[i] & PM_BUSEVENT_MSK;
+ if (!pmc) {
+ /* Bus event or any-PMC direct event */
+ for (pmc = 0; pmc < 4; ++pmc) {
+ if (pmc_inuse & (1 << pmc))
+ continue;
+ grp = (pmc >> 1) & 1;
+ if (isbus) {
+ if (grp == (byte & 1))
+ break;
+ } else if (pmc_grp_use[grp] < 2) {
+ ++pmc_grp_use[grp];
+ break;
+ }
+ }
+ pmc_inuse |= 1 << pmc;
+ } else if (pmc <= 4) {
+ /* Direct event */
+ --pmc;
+ if ((psel == 8 || psel == 0x10) && isbus && (byte & 2))
+ /* add events on higher-numbered bus */
+ mmcr1 |= 1ull << (MMCR1_PMC1_ADDER_SEL_SH - pmc);
+ } else {
+ /* Instructions or run cycles on PMC5/6 */
+ --pmc;
+ }
+ if (isbus && unit == PM_GRS) {
+ bit = psel & 7;
+ grsel = (event[i] >> PM_GRS_SH) & PM_GRS_MSK;
+ mmcr1 |= (u64)grsel << grsel_shift[bit];
+ }
+ if (pmc <= 3)
+ mmcr1 |= psel << MMCR1_PMCSEL_SH(pmc);
+ 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] = 0;
+ return 0;
+}
+
+static void power5_disable_pmc(unsigned int pmc, u64 mmcr[])
+{
+ if (pmc <= 3)
+ mmcr[1] &= ~(0x7fUL << MMCR1_PMCSEL_SH(pmc));
+}
+
+static int power5_generic_events[] = {
+ [PERF_COUNT_CPU_CYCLES] = 0xf,
+ [PERF_COUNT_INSTRUCTIONS] = 0x100009,
+ [PERF_COUNT_CACHE_REFERENCES] = 0x4c1090, /* LD_REF_L1 */
+ [PERF_COUNT_CACHE_MISSES] = 0x3c1088, /* LD_MISS_L1 */
+ [PERF_COUNT_BRANCH_INSTRUCTIONS] = 0x230e4, /* BR_ISSUED */
+ [PERF_COUNT_BRANCH_MISSES] = 0x230e5, /* BR_MPRED_CR */
+};
+
+struct power_pmu power5_pmu = {
+ .n_counter = 6,
+ .max_alternatives = MAX_ALT,
+ .add_fields = 0x7000090000555ull,
+ .test_adder = 0x3000490000000ull,
+ .compute_mmcr = power5_compute_mmcr,
+ .get_constraint = power5_get_constraint,
+ .get_alternatives = power5_get_alternatives,
+ .disable_pmc = power5_disable_pmc,
+ .n_generic = ARRAY_SIZE(power5_generic_events),
+ .generic_events = power5_generic_events,
+};
--
1.5.5.rc3.7.gba13

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