linux/arch/powerpc/perf/isa207-common.c

/*
 * Common Performance counter support functions for PowerISA v2.07 processors.
 *
 * Copyright 2009 Paul Mackerras, IBM Corporation.
 * Copyright 2013 Michael Ellerman, IBM Corporation.
 * Copyright 2016 Madhavan Srinivasan, 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 "isa207-common.h"

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);
}

int isa207_get_constraint(u64 event, unsigned long *maskp, unsigned long *valp)
{
	unsigned int unit, pmc, cache, ebb;
	unsigned long mask, value;

	mask = value = 0;

	if (event & ~EVENT_VALID_MASK)
		return -1;

	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;
	ebb   = (event >> EVENT_EBB_SHIFT)        & EVENT_EBB_MASK;

	if (pmc) {
		u64 base_event;

		if (pmc > 6)
			return -1;

		/* Ignore Linux defined bits when checking event below */
		base_event = event & ~EVENT_LINUX_MASK;

		if (pmc >= 5 && base_event != 0x500fa &&
				base_event != 0x600f4)
			return -1;

		mask  |= CNST_PMC_MASK(pmc);
		value |= CNST_PMC_VAL(pmc);
	}

	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. The bank selector (bit 3) is
		 * irrelevant, as long as the rest of the value is 0.
		 */
		if (cache & 0x7)
			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);
	}

	if (!pmc && ebb)
		/* EBB events must specify the PMC */
		return -1;

	if (event & EVENT_WANTS_BHRB) {
		if (!ebb)
			/* Only EBB events can request BHRB */
			return -1;

		mask  |= CNST_IFM_MASK;
		value |= CNST_IFM_VAL(event >> EVENT_IFM_SHIFT);
	}

	/*
	 * All events must agree on EBB, either all request it or none.
	 * EBB events are pinned & exclusive, so this should never actually
	 * hit, but we leave it as a fallback in case.
	 */
	mask  |= CNST_EBB_VAL(ebb);
	value |= CNST_EBB_MASK;

	*maskp = mask;
	*valp = value;

	return 0;
}

int isa207_compute_mmcr(u64 event[], int n_ev,
			       unsigned int hwc[], unsigned long mmcr[],
			       struct perf_event *pevents[])
{
	unsigned long mmcra, mmcr1, mmcr2, 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 continuous sampling mode, update SDAR on TLB miss */
	mmcra = MMCRA_SDAR_MODE_TLB;
	mmcr1 = mmcr2 = 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) << MMCR1_FAB_SHIFT;
		} 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;
		}

		if (event[i] & EVENT_WANTS_BHRB) {
			val = (event[i] >> EVENT_IFM_SHIFT) & EVENT_IFM_MASK;
			mmcra |= val << MMCRA_IFM_SHIFT;
		}

		if (pevents[i]->attr.exclude_user)
			mmcr2 |= MMCR2_FCP(pmc);

		if (pevents[i]->attr.exclude_hv)
			mmcr2 |= MMCR2_FCH(pmc);

		if (pevents[i]->attr.exclude_kernel) {
			if (cpu_has_feature(CPU_FTR_HVMODE))
				mmcr2 |= MMCR2_FCH(pmc);
			else
				mmcr2 |= MMCR2_FCS(pmc);
		}

		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;

	/* If we're not using PMC 5 or 6, freeze them */
	if (!(pmc_inuse & 0x60))
		mmcr[0] |= MMCR0_FC56;

	mmcr[1] = mmcr1;
	mmcr[2] = mmcra;
	mmcr[3] = mmcr2;

	return 0;
}

void isa207_disable_pmc(unsigned int pmc, unsigned long mmcr[])
{
	if (pmc <= 3)
		mmcr[1] &= ~(0xffUL << MMCR1_PMCSEL_SHIFT(pmc + 1));
}