arch/powerpc/kernel/power4-pmu.c

/*
 * Performance counter support for POWER4 (GP) and POWER4+ (GQ) 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 POWER4
 */
#define PM_PMC_SH	12	/* PMC number (1-based) for direct events */
#define PM_PMC_MSK	0xf
#define PM_UNIT_SH	8	/* TTMMUX number and setting - unit select */
#define PM_UNIT_MSK	0xf
#define PM_LOWER_SH	6
#define PM_LOWER_MSK	1
#define PM_LOWER_MSKS	0x40
#define PM_BYTE_SH	4	/* Byte number of event bus to use */
#define PM_BYTE_MSK	3
#define PM_PMCSEL_MSK	7

/*
 * Unit code values
 */
#define PM_FPU		1
#define PM_ISU1		2
#define PM_IFU		3
#define PM_IDU0		4
#define PM_ISU1_ALT	6
#define PM_ISU2		7
#define PM_IFU_ALT	8
#define PM_LSU0		9
#define PM_LSU1		0xc
#define PM_GPS		0xf

/*
 * Bits in MMCR0 for POWER4
 */
#define MMCR0_PMC1SEL_SH	8
#define MMCR0_PMC2SEL_SH	1
#define MMCR_PMCSEL_MSK		0x1f

/*
 * Bits in MMCR1 for POWER4
 */
#define MMCR1_TTM0SEL_SH	62
#define MMCR1_TTC0SEL_SH	61
#define MMCR1_TTM1SEL_SH	59
#define MMCR1_TTC1SEL_SH	58
#define MMCR1_TTM2SEL_SH	56
#define MMCR1_TTC2SEL_SH	55
#define MMCR1_TTM3SEL_SH	53
#define MMCR1_TTC3SEL_SH	52
#define MMCR1_TTMSEL_MSK	3
#define MMCR1_TD_CP_DBG0SEL_SH	50
#define MMCR1_TD_CP_DBG1SEL_SH	48
#define MMCR1_TD_CP_DBG2SEL_SH	46
#define MMCR1_TD_CP_DBG3SEL_SH	44
#define MMCR1_DEBUG0SEL_SH	43
#define MMCR1_DEBUG1SEL_SH	42
#define MMCR1_DEBUG2SEL_SH	41
#define MMCR1_DEBUG3SEL_SH	40
#define MMCR1_PMC1_ADDER_SEL_SH	39
#define MMCR1_PMC2_ADDER_SEL_SH	38
#define MMCR1_PMC6_ADDER_SEL_SH	37
#define MMCR1_PMC5_ADDER_SEL_SH	36
#define MMCR1_PMC8_ADDER_SEL_SH	35
#define MMCR1_PMC7_ADDER_SEL_SH	34
#define MMCR1_PMC3_ADDER_SEL_SH	33
#define MMCR1_PMC4_ADDER_SEL_SH	32
#define MMCR1_PMC3SEL_SH	27
#define MMCR1_PMC4SEL_SH	22
#define MMCR1_PMC5SEL_SH	17
#define MMCR1_PMC6SEL_SH	12
#define MMCR1_PMC7SEL_SH	7
#define MMCR1_PMC8SEL_SH	2	/* note bit 0 is in MMCRA for GP */

static short mmcr1_adder_bits[8] = {
	MMCR1_PMC1_ADDER_SEL_SH,
	MMCR1_PMC2_ADDER_SEL_SH,
	MMCR1_PMC3_ADDER_SEL_SH,
	MMCR1_PMC4_ADDER_SEL_SH,
	MMCR1_PMC5_ADDER_SEL_SH,
	MMCR1_PMC6_ADDER_SEL_SH,
	MMCR1_PMC7_ADDER_SEL_SH,
	MMCR1_PMC8_ADDER_SEL_SH
};

/*
 * Bits in MMCRA
 */
#define MMCRA_PMC8SEL0_SH	17	/* PMC8SEL bit 0 for GP */

/*
 * Layout of constraint bits:
 * 6666555555555544444444443333333333222222222211111111110000000000
 * 3210987654321098765432109876543210987654321098765432109876543210
 *        |[  >[  >[   >|||[  >[  ><  ><  ><  ><  ><><><><><><><><>
 *        | UC1 UC2 UC3 ||| PS1 PS2 B0  B1  B2  B3 P1P2P3P4P5P6P7P8
 * 	  \SMPL	        ||\TTC3SEL
 * 		        |\TTC_IFU_SEL
 * 		        \TTM2SEL0
 *
 * SMPL - SAMPLE_ENABLE constraint
 *     56: SAMPLE_ENABLE value 0x0100_0000_0000_0000
 *
 * UC1 - unit constraint 1: can't have all three of FPU/ISU1/IDU0|ISU2
 *     55: UC1 error 0x0080_0000_0000_0000
 *     54: FPU events needed 0x0040_0000_0000_0000
 *     53: ISU1 events needed 0x0020_0000_0000_0000
 *     52: IDU0|ISU2 events needed 0x0010_0000_0000_0000
 *
 * UC2 - unit constraint 2: can't have all three of FPU/IFU/LSU0
 *     51: UC2 error 0x0008_0000_0000_0000
 *     50: FPU events needed 0x0004_0000_0000_0000
 *     49: IFU events needed 0x0002_0000_0000_0000
 *     48: LSU0 events needed 0x0001_0000_0000_0000
 *
 * UC3 - unit constraint 3: can't have all four of LSU0/IFU/IDU0|ISU2/ISU1
 *     47: UC3 error 0x8000_0000_0000
 *     46: LSU0 events needed 0x4000_0000_0000
 *     45: IFU events needed 0x2000_0000_0000
 *     44: IDU0|ISU2 events needed 0x1000_0000_0000
 *     43: ISU1 events needed 0x0800_0000_0000
 *
 * TTM2SEL0
 *     42: 0 = IDU0 events needed
 *     	   1 = ISU2 events needed 0x0400_0000_0000
 *
 * TTC_IFU_SEL
 *     41: 0 = IFU.U events needed
 *     	   1 = IFU.L events needed 0x0200_0000_0000
 *
 * TTC3SEL
 *     40: 0 = LSU1.U events needed
 *     	   1 = LSU1.L events needed 0x0100_0000_0000
 *
 * PS1
 *     39: PS1 error 0x0080_0000_0000
 *     36-38: count of events needing PMC1/2/5/6 0x0070_0000_0000
 *
 * PS2
 *     35: PS2 error 0x0008_0000_0000
 *     32-34: count of events needing PMC3/4/7/8 0x0007_0000_0000
 *
 * B0
 *     28-31: Byte 0 event source 0xf000_0000
 *     	   1 = FPU
 * 	   2 = ISU1
 * 	   3 = IFU
 * 	   4 = IDU0
 * 	   7 = ISU2
 * 	   9 = LSU0
 * 	   c = LSU1
 * 	   f = GPS
 *
 * B1, B2, B3
 *     24-27, 20-23, 16-19: Byte 1, 2, 3 event sources
 *
 * P8
 *     15: P8 error 0x8000
 *     14-15: Count of events needing PMC8
 *
 * P1..P7
 *     0-13: Count of events needing PMC1..PMC7
 *
 * Note: this doesn't allow events using IFU.U to be combined with events
 * using IFU.L, though that is feasible (using TTM0 and TTM2).  However
 * there are no listed events for IFU.L (they are debug events not
 * verified for performance monitoring) so this shouldn't cause a
 * problem.
 */

static struct unitinfo {
	u64	value, mask;
	int	unit;
	int	lowerbit;
} p4_unitinfo[16] = {
	[PM_FPU]  = { 0x44000000000000ull, 0x88000000000000ull, PM_FPU, 0 },
	[PM_ISU1] = { 0x20080000000000ull, 0x88000000000000ull, PM_ISU1, 0 },
	[PM_ISU1_ALT] =
		    { 0x20080000000000ull, 0x88000000000000ull, PM_ISU1, 0 },
	[PM_IFU]  = { 0x02200000000000ull, 0x08820000000000ull, PM_IFU, 41 },
	[PM_IFU_ALT] =
		    { 0x02200000000000ull, 0x08820000000000ull, PM_IFU, 41 },
	[PM_IDU0] = { 0x10100000000000ull, 0x80840000000000ull, PM_IDU0, 1 },
	[PM_ISU2] = { 0x10140000000000ull, 0x80840000000000ull, PM_ISU2, 0 },
	[PM_LSU0] = { 0x01400000000000ull, 0x08800000000000ull, PM_LSU0, 0 },
	[PM_LSU1] = { 0x00000000000000ull, 0x00010000000000ull, PM_LSU1, 40 },
	[PM_GPS]  = { 0x00000000000000ull, 0x00000000000000ull, PM_GPS, 0 }
};

static unsigned char direct_marked_event[8] = {
	(1<<2) | (1<<3),	/* PMC1: PM_MRK_GRP_DISP, PM_MRK_ST_CMPL */
	(1<<3) | (1<<5),	/* PMC2: PM_THRESH_TIMEO, PM_MRK_BRU_FIN */
	(1<<3),			/* PMC3: PM_MRK_ST_CMPL_INT */
	(1<<4) | (1<<5),	/* PMC4: PM_MRK_GRP_CMPL, PM_MRK_CRU_FIN */
	(1<<4) | (1<<5),	/* PMC5: PM_MRK_GRP_TIMEO */
	(1<<3) | (1<<4) | (1<<5),
		/* PMC6: PM_MRK_ST_GPS, PM_MRK_FXU_FIN, PM_MRK_GRP_ISSUED */
	(1<<4) | (1<<5),	/* PMC7: PM_MRK_FPU_FIN, PM_MRK_INST_FIN */
	(1<<4),			/* PMC8: PM_MRK_LSU_FIN */
};

/*
 * 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 p4_marked_instr_event(u64 event)
{
	int pmc, psel, unit, byte, bit;
	unsigned int mask;

	pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
	psel = event & PM_PMCSEL_MSK;
	if (pmc) {
		if (direct_marked_event[pmc - 1] & (1 << psel))
			return 1;
		if (psel == 0)		/* add events */
			bit = (pmc <= 4)? pmc - 1: 8 - pmc;
		else if (psel == 6)	/* decode events */
			bit = 4;
		else
			return 0;
	} else
		bit = psel;

	byte = (event >> PM_BYTE_SH) & PM_BYTE_MSK;
	unit = (event >> PM_UNIT_SH) & PM_UNIT_MSK;
	mask = 0;
	switch (unit) {
	case PM_LSU1:
		if (event & PM_LOWER_MSKS)
			mask = 1 << 28;		/* byte 7 bit 4 */
		else
			mask = 6 << 24;		/* byte 3 bits 1 and 2 */
		break;
	case PM_LSU0:
		/* byte 3, bit 3; byte 2 bits 0,2,3,4,5; byte 1 */
		mask = 0x083dff00;
	}
	return (mask >> (byte * 8 + bit)) & 1;
}

static int p4_get_constraint(u64 event, u64 *maskp, u64 *valp)
{
	int pmc, byte, unit, lower, sh;
	u64 mask = 0, value = 0;
	int grp = -1;

	pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
	if (pmc) {
		if (pmc > 8)
			return -1;
		sh = (pmc - 1) * 2;
		mask |= 2 << sh;
		value |= 1 << sh;
		grp = ((pmc - 1) >> 1) & 1;
	}
	unit = (event >> PM_UNIT_SH) & PM_UNIT_MSK;
	byte = (event >> PM_BYTE_SH) & PM_BYTE_MSK;
	if (unit) {
		lower = (event >> PM_LOWER_SH) & PM_LOWER_MSK;

		/*
		 * Bus events on bytes 0 and 2 can be counted
		 * on PMC1/2/5/6; bytes 1 and 3 on PMC3/4/7/8.
		 */
		if (!pmc)
			grp = byte & 1;

		if (!p4_unitinfo[unit].unit)
			return -1;
		mask  |= p4_unitinfo[unit].mask;
		value |= p4_unitinfo[unit].value;
		sh = p4_unitinfo[unit].lowerbit;
		if (sh > 1)
			value |= (u64)lower << sh;
		else if (lower != sh)
			return -1;
		unit = p4_unitinfo[unit].unit;

		/* Set byte lane select field */
		mask  |= 0xfULL << (28 - 4 * byte);
		value |= (u64)unit << (28 - 4 * byte);
	}
	if (grp == 0) {
		/* increment PMC1/2/5/6 field */
		mask  |= 0x8000000000ull;
		value |= 0x1000000000ull;
	} else {
		/* increment PMC3/4/7/8 field */
		mask  |= 0x800000000ull;
		value |= 0x100000000ull;
	}

	/* Marked instruction events need sample_enable set */
	if (p4_marked_instr_event(event)) {
		mask  |= 1ull << 56;
		value |= 1ull << 56;
	}

	/* PMCSEL=6 decode events on byte 2 need sample_enable clear */
	if (pmc && (event & PM_PMCSEL_MSK) == 6 && byte == 2)
		mask  |= 1ull << 56;

	*maskp = mask;
	*valp = value;
	return 0;
}

static unsigned int ppc_inst_cmpl[] = {
	0x1001, 0x4001, 0x6001, 0x7001, 0x8001
};

static int p4_get_alternatives(u64 event, unsigned int flags, u64 alt[])
{
	int i, j, na;

	alt[0] = event;
	na = 1;

	/* 2 possibilities for PM_GRP_DISP_REJECT */
	if (event == 0x8003 || event == 0x0224) {
		alt[1] = event ^ (0x8003 ^ 0x0224);
		return 2;
	}

	/* 2 possibilities for PM_ST_MISS_L1 */
	if (event == 0x0c13 || event == 0x0c23) {
		alt[1] = event ^ (0x0c13 ^ 0x0c23);
		return 2;
	}

	/* several possibilities for PM_INST_CMPL */
	for (i = 0; i < ARRAY_SIZE(ppc_inst_cmpl); ++i) {
		if (event == ppc_inst_cmpl[i]) {
			for (j = 0; j < ARRAY_SIZE(ppc_inst_cmpl); ++j)
				if (j != i)
					alt[na++] = ppc_inst_cmpl[j];
			break;
		}
	}

	return na;
}

static int p4_compute_mmcr(u64 event[], int n_ev,
			   unsigned int hwc[], u64 mmcr[])
{
	u64 mmcr0 = 0, mmcr1 = 0, mmcra = 0;
	unsigned int pmc, unit, byte, psel, lower;
	unsigned int ttm, grp;
	unsigned int pmc_inuse = 0;
	unsigned int pmc_grp_use[2];
	unsigned char busbyte[4];
	unsigned char unituse[16];
	unsigned int unitlower = 0;
	int i;

	if (n_ev > 8)
		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_inuse & (1 << (pmc - 1)))
				return -1;
			pmc_inuse |= 1 << (pmc - 1);
			/* count 1/2/5/6 vs 3/4/7/8 use */
			++pmc_grp_use[((pmc - 1) >> 1) & 1];
		}
		unit = (event[i] >> PM_UNIT_SH) & PM_UNIT_MSK;
		byte = (event[i] >> PM_BYTE_SH) & PM_BYTE_MSK;
		lower = (event[i] >> PM_LOWER_SH) & PM_LOWER_MSK;
		if (unit) {
			if (!pmc)
				++pmc_grp_use[byte & 1];
			if (unit == 6 || unit == 8)
				/* map alt ISU1/IFU codes: 6->2, 8->3 */
				unit = (unit >> 1) - 1;
			if (busbyte[byte] && busbyte[byte] != unit)
				return -1;
			busbyte[byte] = unit;
			lower <<= unit;
			if (unituse[unit] && lower != (unitlower & lower))
				return -1;
			unituse[unit] = 1;
			unitlower |= lower;
		}
	}
	if (pmc_grp_use[0] > 4 || pmc_grp_use[1] > 4)
		return -1;

	/*
	 * Assign resources and set multiplexer selects.
	 *
	 * Units 1,2,3 are on TTM0, 4,6,7 on TTM1, 8,10 on TTM2.
	 * Each TTMx can only select one unit, but since
	 * units 2 and 6 are both ISU1, and 3 and 8 are both IFU,
	 * we have some choices.
	 */
	if (unituse[2] & (unituse[1] | (unituse[3] & unituse[9]))) {
		unituse[6] = 1;		/* Move 2 to 6 */
		unituse[2] = 0;
	}
	if (unituse[3] & (unituse[1] | unituse[2])) {
		unituse[8] = 1;		/* Move 3 to 8 */
		unituse[3] = 0;
		unitlower = (unitlower & ~8) | ((unitlower & 8) << 5);
	}
	/* Check only one unit per TTMx */
	if (unituse[1] + unituse[2] + unituse[3] > 1 ||
	    unituse[4] + unituse[6] + unituse[7] > 1 ||
	    unituse[8] + unituse[9] > 1 ||
	    (unituse[5] | unituse[10] | unituse[11] |
	     unituse[13] | unituse[14]))
		return -1;

	/* Set TTMxSEL fields.  Note, units 1-3 => TTM0SEL codes 0-2 */
	mmcr1 |= (u64)(unituse[3] * 2 + unituse[2]) << MMCR1_TTM0SEL_SH;
	mmcr1 |= (u64)(unituse[7] * 3 + unituse[6] * 2) << MMCR1_TTM1SEL_SH;
	mmcr1 |= (u64)unituse[9] << MMCR1_TTM2SEL_SH;

	/* Set TTCxSEL fields. */
	if (unitlower & 0xe)
		mmcr1 |= 1ull << MMCR1_TTC0SEL_SH;
	if (unitlower & 0xf0)
		mmcr1 |= 1ull << MMCR1_TTC1SEL_SH;
	if (unitlower & 0xf00)
		mmcr1 |= 1ull << MMCR1_TTC2SEL_SH;
	if (unitlower & 0x7000)
		mmcr1 |= 1ull << MMCR1_TTC3SEL_SH;

	/* Set byte lane select fields. */
	for (byte = 0; byte < 4; ++byte) {
		unit = busbyte[byte];
		if (!unit)
			continue;
		if (unit == 0xf) {
			/* special case for GPS */
			mmcr1 |= 1ull << (MMCR1_DEBUG0SEL_SH - byte);
		} else {
			if (!unituse[unit])
				ttm = unit - 1;		/* 2->1, 3->2 */
			else
				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;
		if (!pmc) {
			/* Bus event or 00xxx direct event (off or cycles) */
			if (unit)
				psel |= 0x10 | ((byte & 2) << 2);
			for (pmc = 0; pmc < 8; ++pmc) {
				if (pmc_inuse & (1 << pmc))
					continue;
				grp = (pmc >> 1) & 1;
				if (unit) {
					if (grp == (byte & 1))
						break;
				} else if (pmc_grp_use[grp] < 4) {
					++pmc_grp_use[grp];
					break;
				}
			}
			pmc_inuse |= 1 << pmc;
		} else {
			/* Direct event */
			--pmc;
			if (psel == 0 && (byte & 2))
				/* add events on higher-numbered bus */
				mmcr1 |= 1ull << mmcr1_adder_bits[pmc];
			else if (psel == 6 && byte == 3)
				/* seem to need to set sample_enable here */
				mmcra |= MMCRA_SAMPLE_ENABLE;
			psel |= 8;
		}
		if (pmc <= 1)
			mmcr0 |= psel << (MMCR0_PMC1SEL_SH - 7 * pmc);
		else
			mmcr1 |= psel << (MMCR1_PMC3SEL_SH - 5 * (pmc - 2));
		if (pmc == 7)	/* PMC8 */
			mmcra |= (psel & 1) << MMCRA_PMC8SEL0_SH;
		hwc[i] = pmc;
		if (p4_marked_instr_event(event[i]))
			mmcra |= MMCRA_SAMPLE_ENABLE;
	}

	if (pmc_inuse & 1)
		mmcr0 |= MMCR0_PMC1CE;
	if (pmc_inuse & 0xfe)
		mmcr0 |= MMCR0_PMCjCE;

	mmcra |= 0x2000;	/* mark only one IOP per PPC instruction */

	/* Return MMCRx values */
	mmcr[0] = mmcr0;
	mmcr[1] = mmcr1;
	mmcr[2] = mmcra;
	return 0;
}

static void p4_disable_pmc(unsigned int pmc, u64 mmcr[])
{
	/*
	 * Setting the PMCxSEL field to 0 disables PMC x.
	 * (Note that pmc is 0-based here, not 1-based.)
	 */
	if (pmc <= 1) {
		mmcr[0] &= ~(0x1fUL << (MMCR0_PMC1SEL_SH - 7 * pmc));
	} else {
		mmcr[1] &= ~(0x1fUL << (MMCR1_PMC3SEL_SH - 5 * (pmc - 2)));
		if (pmc == 7)
			mmcr[2] &= ~(1UL << MMCRA_PMC8SEL0_SH);
	}
}

static int p4_generic_events[] = {
	[PERF_COUNT_CPU_CYCLES] = 7,
	[PERF_COUNT_INSTRUCTIONS] = 0x1001,
	[PERF_COUNT_CACHE_REFERENCES] = 0x8c10,		/* PM_LD_REF_L1 */
	[PERF_COUNT_CACHE_MISSES] = 0x3c10,		/* PM_LD_MISS_L1 */
	[PERF_COUNT_BRANCH_INSTRUCTIONS] = 0x330,	/* PM_BR_ISSUED */
	[PERF_COUNT_BRANCH_MISSES] = 0x331,		/* PM_BR_MPRED_CR */
};

struct power_pmu power4_pmu = {
	.n_counter = 8,
	.max_alternatives = 5,
	.add_fields = 0x0000001100005555ull,
	.test_adder = 0x0011083300000000ull,
	.compute_mmcr = p4_compute_mmcr,
	.get_constraint = p4_get_constraint,
	.get_alternatives = p4_get_alternatives,
	.disable_pmc = p4_disable_pmc,
	.n_generic = ARRAY_SIZE(p4_generic_events),
	.generic_events = p4_generic_events,
};