arch/powerpc/kernel/power6-pmu.c

/*
 * Performance counter support for POWER6 processors.
 *
 * Copyright 2008-2009 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 POWER6
 */
#define PM_PMC_SH	20	/* PMC number (1-based) for direct events */
#define PM_PMC_MSK	0x7
#define PM_PMC_MSKS	(PM_PMC_MSK << PM_PMC_SH)
#define PM_UNIT_SH	16	/* Unit event comes (TTMxSEL encoding) */
#define PM_UNIT_MSK	0xf
#define PM_UNIT_MSKS	(PM_UNIT_MSK << PM_UNIT_SH)
#define PM_LLAV		0x8000	/* Load lookahead match value */
#define PM_LLA		0x4000	/* Load lookahead match enable */
#define PM_BYTE_SH	12	/* Byte of event bus to use */
#define PM_BYTE_MSK	3
#define PM_SUBUNIT_SH	8	/* Subunit event comes from (NEST_SEL enc.) */
#define PM_SUBUNIT_MSK	7
#define PM_SUBUNIT_MSKS	(PM_SUBUNIT_MSK << PM_SUBUNIT_SH)
#define PM_PMCSEL_MSK	0xff	/* PMCxSEL value */
#define PM_BUSEVENT_MSK	0xf3700

/*
 * Bits in MMCR1 for POWER6
 */
#define MMCR1_TTM0SEL_SH	60
#define MMCR1_TTMSEL_SH(n)	(MMCR1_TTM0SEL_SH - (n) * 4)
#define MMCR1_TTMSEL_MSK	0xf
#define MMCR1_TTMSEL(m, n)	(((m) >> MMCR1_TTMSEL_SH(n)) & MMCR1_TTMSEL_MSK)
#define MMCR1_NESTSEL_SH	45
#define MMCR1_NESTSEL_MSK	0x7
#define MMCR1_NESTSEL(m)	(((m) >> MMCR1_NESTSEL_SH) & MMCR1_NESTSEL_MSK)
#define MMCR1_PMC1_LLA		((u64)1 << 44)
#define MMCR1_PMC1_LLA_VALUE	((u64)1 << 39)
#define MMCR1_PMC1_ADDR_SEL	((u64)1 << 35)
#define MMCR1_PMC1SEL_SH	24
#define MMCR1_PMCSEL_SH(n)	(MMCR1_PMC1SEL_SH - (n) * 8)
#define MMCR1_PMCSEL_MSK	0xff

/*
 * Assign PMC numbers and compute MMCR1 value for a set of events
 */
static int p6_compute_mmcr(unsigned int event[], int n_ev,
			   unsigned int hwc[], u64 mmcr[])
{
	u64 mmcr1 = 0;
	int i;
	unsigned int pmc, ev, b, u, s, psel;
	unsigned int ttmset = 0;
	unsigned int pmc_inuse = 0;

	if (n_ev > 4)
		return -1;
	for (i = 0; i < n_ev; ++i) {
		pmc = (event[i] >> PM_PMC_SH) & PM_PMC_MSK;
		if (pmc) {
			if (pmc_inuse & (1 << (pmc - 1)))
				return -1;	/* collision! */
			pmc_inuse |= 1 << (pmc - 1);
		}
	}
	for (i = 0; i < n_ev; ++i) {
		ev = event[i];
		pmc = (ev >> PM_PMC_SH) & PM_PMC_MSK;
		if (pmc) {
			--pmc;
		} else {
			/* can go on any PMC; find a free one */
			for (pmc = 0; pmc < 4; ++pmc)
				if (!(pmc_inuse & (1 << pmc)))
					break;
			pmc_inuse |= 1 << pmc;
		}
		hwc[i] = pmc;
		psel = ev & PM_PMCSEL_MSK;
		if (ev & PM_BUSEVENT_MSK) {
			/* this event uses the event bus */
			b = (ev >> PM_BYTE_SH) & PM_BYTE_MSK;
			u = (ev >> PM_UNIT_SH) & PM_UNIT_MSK;
			/* check for conflict on this byte of event bus */
			if ((ttmset & (1 << b)) && MMCR1_TTMSEL(mmcr1, b) != u)
				return -1;
			mmcr1 |= (u64)u << MMCR1_TTMSEL_SH(b);
			ttmset |= 1 << b;
			if (u == 5) {
				/* Nest events have a further mux */
				s = (ev >> PM_SUBUNIT_SH) & PM_SUBUNIT_MSK;
				if ((ttmset & 0x10) &&
				    MMCR1_NESTSEL(mmcr1) != s)
					return -1;
				ttmset |= 0x10;
				mmcr1 |= (u64)s << MMCR1_NESTSEL_SH;
			}
			if (0x30 <= psel && psel <= 0x3d) {
				/* these need the PMCx_ADDR_SEL bits */
				if (b >= 2)
					mmcr1 |= MMCR1_PMC1_ADDR_SEL >> pmc;
			}
			/* bus select values are different for PMC3/4 */
			if (pmc >= 2 && (psel & 0x90) == 0x80)
				psel ^= 0x20;
		}
		if (ev & PM_LLA) {
			mmcr1 |= MMCR1_PMC1_LLA >> pmc;
			if (ev & PM_LLAV)
				mmcr1 |= MMCR1_PMC1_LLA_VALUE >> pmc;
		}
		mmcr1 |= (u64)psel << MMCR1_PMCSEL_SH(pmc);
	}
	mmcr[0] = 0;
	if (pmc_inuse & 1)
		mmcr[0] = MMCR0_PMC1CE;
	if (pmc_inuse & 0xe)
		mmcr[0] |= MMCR0_PMCjCE;
	mmcr[1] = mmcr1;
	mmcr[2] = 0;
	return 0;
}

/*
 * Layout of constraint bits:
 *
 *	0-1	add field: number of uses of PMC1 (max 1)
 *	2-3, 4-5, 6-7: ditto for PMC2, 3, 4
 *	8-10	select field: nest (subunit) event selector
 *	16-19	select field: unit on byte 0 of event bus
 *	20-23, 24-27, 28-31 ditto for bytes 1, 2, 3
 */
static int p6_get_constraint(unsigned int event, u64 *maskp, u64 *valp)
{
	int pmc, byte, sh;
	unsigned int mask = 0, value = 0;

	pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
	if (pmc) {
		if (pmc > 4)
			return -1;
		sh = (pmc - 1) * 2;
		mask |= 2 << sh;
		value |= 1 << sh;
	}
	if (event & PM_BUSEVENT_MSK) {
		byte = (event >> PM_BYTE_SH) & PM_BYTE_MSK;
		sh = byte * 4;
		mask |= PM_UNIT_MSKS << sh;
		value |= (event & PM_UNIT_MSKS) << sh;
		if ((event & PM_UNIT_MSKS) == (5 << PM_UNIT_SH)) {
			mask |= PM_SUBUNIT_MSKS;
			value |= event & PM_SUBUNIT_MSKS;
		}
	}
	*maskp = mask;
	*valp = value;
	return 0;
}

#define MAX_ALT	4	/* at most 4 alternatives for any event */

static const unsigned int event_alternatives[][MAX_ALT] = {
	{ 0x0130e8, 0x2000f6, 0x3000fc },	/* PM_PTEG_RELOAD_VALID */
	{ 0x080080, 0x10000d, 0x30000c, 0x4000f0 }, /* PM_LD_MISS_L1 */
	{ 0x080088, 0x200054, 0x3000f0 },	/* PM_ST_MISS_L1 */
	{ 0x10000a, 0x2000f4 },			/* PM_RUN_CYC */
	{ 0x10000b, 0x2000f5 },			/* PM_RUN_COUNT */
	{ 0x10000e, 0x400010 },			/* PM_PURR */
	{ 0x100010, 0x4000f8 },			/* PM_FLUSH */
	{ 0x10001a, 0x200010 },			/* PM_MRK_INST_DISP */
	{ 0x100026, 0x3000f8 },			/* PM_TB_BIT_TRANS */
	{ 0x100054, 0x2000f0 },			/* PM_ST_FIN */
	{ 0x100056, 0x2000fc },			/* PM_L1_ICACHE_MISS */
	{ 0x1000f0, 0x40000a },			/* PM_INST_IMC_MATCH_CMPL */
	{ 0x1000f8, 0x200008 },			/* PM_GCT_EMPTY_CYC */
	{ 0x1000fc, 0x400006 },			/* PM_LSU_DERAT_MISS_CYC */
	{ 0x20000e, 0x400007 },			/* PM_LSU_DERAT_MISS */
	{ 0x200012, 0x300012 },			/* PM_INST_DISP */
	{ 0x2000f2, 0x3000f2 },			/* PM_INST_DISP */
	{ 0x2000f8, 0x300010 },			/* PM_EXT_INT */
	{ 0x2000fe, 0x300056 },			/* PM_DATA_FROM_L2MISS */
	{ 0x2d0030, 0x30001a },			/* PM_MRK_FPU_FIN */
	{ 0x30000a, 0x400018 },			/* PM_MRK_INST_FIN */
	{ 0x3000f6, 0x40000e },			/* PM_L1_DCACHE_RELOAD_VALID */
	{ 0x3000fe, 0x400056 },			/* PM_DATA_FROM_L3MISS */
};

/*
 * This could be made more efficient with a binary search on
 * a presorted list, if necessary
 */
static int find_alternatives_list(unsigned int event)
{
	int i, j;
	unsigned int alt;

	for (i = 0; i < ARRAY_SIZE(event_alternatives); ++i) {
		if (event < event_alternatives[i][0])
			return -1;
		for (j = 0; j < MAX_ALT; ++j) {
			alt = event_alternatives[i][j];
			if (!alt || event < alt)
				break;
			if (event == alt)
				return i;
		}
	}
	return -1;
}

static int p6_get_alternatives(unsigned int event, unsigned int alt[])
{
	int i, j;
	unsigned int aevent, psel, pmc;
	unsigned int nalt = 1;

	alt[0] = event;

	/* check the alternatives table */
	i = find_alternatives_list(event);
	if (i >= 0) {
		/* copy out alternatives from list */
		for (j = 0; j < MAX_ALT; ++j) {
			aevent = event_alternatives[i][j];
			if (!aevent)
				break;
			if (aevent != event)
				alt[nalt++] = aevent;
		}

	} else {
		/* Check for alternative ways of computing sum events */
		/* PMCSEL 0x32 counter N == PMCSEL 0x34 counter 5-N */
		psel = event & (PM_PMCSEL_MSK & ~1);	/* ignore edge bit */
		pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
		if (pmc && (psel == 0x32 || psel == 0x34))
			alt[nalt++] = ((event ^ 0x6) & ~PM_PMC_MSKS) |
				((5 - pmc) << PM_PMC_SH);

		/* PMCSEL 0x38 counter N == PMCSEL 0x3a counter N+/-2 */
		if (pmc && (psel == 0x38 || psel == 0x3a))
			alt[nalt++] = ((event ^ 0x2) & ~PM_PMC_MSKS) |
				((pmc > 2? pmc - 2: pmc + 2) << PM_PMC_SH);
	}

	return nalt;
}

static void p6_disable_pmc(unsigned int pmc, u64 mmcr[])
{
	/* Set PMCxSEL to 0 to disable PMCx */
	mmcr[1] &= ~(0xffUL << MMCR1_PMCSEL_SH(pmc));
}

static int power6_generic_events[] = {
	[PERF_COUNT_CPU_CYCLES] = 0x1e,
	[PERF_COUNT_INSTRUCTIONS] = 2,
	[PERF_COUNT_CACHE_REFERENCES] = 0x280030,	/* LD_REF_L1 */
	[PERF_COUNT_CACHE_MISSES] = 0x30000c,		/* LD_MISS_L1 */
	[PERF_COUNT_BRANCH_INSTRUCTIONS] = 0x410a0,	/* BR_PRED */ 
	[PERF_COUNT_BRANCH_MISSES] = 0x400052,		/* BR_MPRED */
};

struct power_pmu power6_pmu = {
	.n_counter = 4,
	.max_alternatives = MAX_ALT,
	.add_fields = 0x55,
	.test_adder = 0,
	.compute_mmcr = p6_compute_mmcr,
	.get_constraint = p6_get_constraint,
	.get_alternatives = p6_get_alternatives,
	.disable_pmc = p6_disable_pmc,
	.n_generic = ARRAY_SIZE(power6_generic_events),
	.generic_events = power6_generic_events,
};