cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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mpc7450-pmu.c (10550B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Performance counter support for MPC7450-family processors.
      4 *
      5 * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
      6 */
      7#include <linux/string.h>
      8#include <linux/perf_event.h>
      9#include <asm/reg.h>
     10#include <asm/cputable.h>
     11
     12#define N_COUNTER	6	/* Number of hardware counters */
     13#define MAX_ALT		3	/* Maximum number of event alternative codes */
     14
     15/*
     16 * Bits in event code for MPC7450 family
     17 */
     18#define PM_THRMULT_MSKS	0x40000
     19#define PM_THRESH_SH	12
     20#define PM_THRESH_MSK	0x3f
     21#define PM_PMC_SH	8
     22#define PM_PMC_MSK	7
     23#define PM_PMCSEL_MSK	0x7f
     24
     25/*
     26 * Classify events according to how specific their PMC requirements are.
     27 * Result is:
     28 *	0: can go on any PMC
     29 *	1: can go on PMCs 1-4
     30 *	2: can go on PMCs 1,2,4
     31 *	3: can go on PMCs 1 or 2
     32 *	4: can only go on one PMC
     33 *	-1: event code is invalid
     34 */
     35#define N_CLASSES	5
     36
     37static int mpc7450_classify_event(u32 event)
     38{
     39	int pmc;
     40
     41	pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
     42	if (pmc) {
     43		if (pmc > N_COUNTER)
     44			return -1;
     45		return 4;
     46	}
     47	event &= PM_PMCSEL_MSK;
     48	if (event <= 1)
     49		return 0;
     50	if (event <= 7)
     51		return 1;
     52	if (event <= 13)
     53		return 2;
     54	if (event <= 22)
     55		return 3;
     56	return -1;
     57}
     58
     59/*
     60 * Events using threshold and possible threshold scale:
     61 *	code	scale?	name
     62 *	11e	N	PM_INSTQ_EXCEED_CYC
     63 *	11f	N	PM_ALTV_IQ_EXCEED_CYC
     64 *	128	Y	PM_DTLB_SEARCH_EXCEED_CYC
     65 *	12b	Y	PM_LD_MISS_EXCEED_L1_CYC
     66 *	220	N	PM_CQ_EXCEED_CYC
     67 *	30c	N	PM_GPR_RB_EXCEED_CYC
     68 *	30d	?	PM_FPR_IQ_EXCEED_CYC ?
     69 *	311	Y	PM_ITLB_SEARCH_EXCEED
     70 *	410	N	PM_GPR_IQ_EXCEED_CYC
     71 */
     72
     73/*
     74 * Return use of threshold and threshold scale bits:
     75 * 0 = uses neither, 1 = uses threshold, 2 = uses both
     76 */
     77static int mpc7450_threshold_use(u32 event)
     78{
     79	int pmc, sel;
     80
     81	pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
     82	sel = event & PM_PMCSEL_MSK;
     83	switch (pmc) {
     84	case 1:
     85		if (sel == 0x1e || sel == 0x1f)
     86			return 1;
     87		if (sel == 0x28 || sel == 0x2b)
     88			return 2;
     89		break;
     90	case 2:
     91		if (sel == 0x20)
     92			return 1;
     93		break;
     94	case 3:
     95		if (sel == 0xc || sel == 0xd)
     96			return 1;
     97		if (sel == 0x11)
     98			return 2;
     99		break;
    100	case 4:
    101		if (sel == 0x10)
    102			return 1;
    103		break;
    104	}
    105	return 0;
    106}
    107
    108/*
    109 * Layout of constraint bits:
    110 * 33222222222211111111110000000000
    111 * 10987654321098765432109876543210
    112 *  |<    ><  > < > < ><><><><><><>
    113 *  TS TV   G4   G3  G2P6P5P4P3P2P1
    114 *
    115 * P1 - P6
    116 *	0 - 11: Count of events needing PMC1 .. PMC6
    117 *
    118 * G2
    119 *	12 - 14: Count of events needing PMC1 or PMC2
    120 *
    121 * G3
    122 *	16 - 18: Count of events needing PMC1, PMC2 or PMC4
    123 *
    124 * G4
    125 *	20 - 23: Count of events needing PMC1, PMC2, PMC3 or PMC4
    126 *
    127 * TV
    128 *	24 - 29: Threshold value requested
    129 *
    130 * TS
    131 *	30: Threshold scale value requested
    132 */
    133
    134static u32 pmcbits[N_COUNTER][2] = {
    135	{ 0x00844002, 0x00111001 },	/* PMC1 mask, value: P1,G2,G3,G4 */
    136	{ 0x00844008, 0x00111004 },	/* PMC2: P2,G2,G3,G4 */
    137	{ 0x00800020, 0x00100010 },	/* PMC3: P3,G4 */
    138	{ 0x00840080, 0x00110040 },	/* PMC4: P4,G3,G4 */
    139	{ 0x00000200, 0x00000100 },	/* PMC5: P5 */
    140	{ 0x00000800, 0x00000400 }	/* PMC6: P6 */
    141};
    142
    143static u32 classbits[N_CLASSES - 1][2] = {
    144	{ 0x00000000, 0x00000000 },	/* class 0: no constraint */
    145	{ 0x00800000, 0x00100000 },	/* class 1: G4 */
    146	{ 0x00040000, 0x00010000 },	/* class 2: G3 */
    147	{ 0x00004000, 0x00001000 },	/* class 3: G2 */
    148};
    149
    150static int mpc7450_get_constraint(u64 event, unsigned long *maskp,
    151				  unsigned long *valp, u64 event_config1 __maybe_unused)
    152{
    153	int pmc, class;
    154	u32 mask, value;
    155	int thresh, tuse;
    156
    157	class = mpc7450_classify_event(event);
    158	if (class < 0)
    159		return -1;
    160	if (class == 4) {
    161		pmc = ((unsigned int)event >> PM_PMC_SH) & PM_PMC_MSK;
    162		mask  = pmcbits[pmc - 1][0];
    163		value = pmcbits[pmc - 1][1];
    164	} else {
    165		mask  = classbits[class][0];
    166		value = classbits[class][1];
    167	}
    168
    169	tuse = mpc7450_threshold_use(event);
    170	if (tuse) {
    171		thresh = ((unsigned int)event >> PM_THRESH_SH) & PM_THRESH_MSK;
    172		mask  |= 0x3f << 24;
    173		value |= thresh << 24;
    174		if (tuse == 2) {
    175			mask |= 0x40000000;
    176			if ((unsigned int)event & PM_THRMULT_MSKS)
    177				value |= 0x40000000;
    178		}
    179	}
    180
    181	*maskp = mask;
    182	*valp = value;
    183	return 0;
    184}
    185
    186static const unsigned int event_alternatives[][MAX_ALT] = {
    187	{ 0x217, 0x317 },		/* PM_L1_DCACHE_MISS */
    188	{ 0x418, 0x50f, 0x60f },	/* PM_SNOOP_RETRY */
    189	{ 0x502, 0x602 },		/* PM_L2_HIT */
    190	{ 0x503, 0x603 },		/* PM_L3_HIT */
    191	{ 0x504, 0x604 },		/* PM_L2_ICACHE_MISS */
    192	{ 0x505, 0x605 },		/* PM_L3_ICACHE_MISS */
    193	{ 0x506, 0x606 },		/* PM_L2_DCACHE_MISS */
    194	{ 0x507, 0x607 },		/* PM_L3_DCACHE_MISS */
    195	{ 0x50a, 0x623 },		/* PM_LD_HIT_L3 */
    196	{ 0x50b, 0x624 },		/* PM_ST_HIT_L3 */
    197	{ 0x50d, 0x60d },		/* PM_L2_TOUCH_HIT */
    198	{ 0x50e, 0x60e },		/* PM_L3_TOUCH_HIT */
    199	{ 0x512, 0x612 },		/* PM_INT_LOCAL */
    200	{ 0x513, 0x61d },		/* PM_L2_MISS */
    201	{ 0x514, 0x61e },		/* PM_L3_MISS */
    202};
    203
    204/*
    205 * Scan the alternatives table for a match and return the
    206 * index into the alternatives table if found, else -1.
    207 */
    208static int find_alternative(u32 event)
    209{
    210	int i, j;
    211
    212	for (i = 0; i < ARRAY_SIZE(event_alternatives); ++i) {
    213		if (event < event_alternatives[i][0])
    214			break;
    215		for (j = 0; j < MAX_ALT && event_alternatives[i][j]; ++j)
    216			if (event == event_alternatives[i][j])
    217				return i;
    218	}
    219	return -1;
    220}
    221
    222static int mpc7450_get_alternatives(u64 event, unsigned int flags, u64 alt[])
    223{
    224	int i, j, nalt = 1;
    225	u32 ae;
    226
    227	alt[0] = event;
    228	nalt = 1;
    229	i = find_alternative((u32)event);
    230	if (i >= 0) {
    231		for (j = 0; j < MAX_ALT; ++j) {
    232			ae = event_alternatives[i][j];
    233			if (ae && ae != (u32)event)
    234				alt[nalt++] = ae;
    235		}
    236	}
    237	return nalt;
    238}
    239
    240/*
    241 * Bitmaps of which PMCs each class can use for classes 0 - 3.
    242 * Bit i is set if PMC i+1 is usable.
    243 */
    244static const u8 classmap[N_CLASSES] = {
    245	0x3f, 0x0f, 0x0b, 0x03, 0
    246};
    247
    248/* Bit position and width of each PMCSEL field */
    249static const int pmcsel_shift[N_COUNTER] = {
    250	6,	0,	27,	22,	17,	11
    251};
    252static const u32 pmcsel_mask[N_COUNTER] = {
    253	0x7f,	0x3f,	0x1f,	0x1f,	0x1f,	0x3f
    254};
    255
    256/*
    257 * Compute MMCR0/1/2 values for a set of events.
    258 */
    259static int mpc7450_compute_mmcr(u64 event[], int n_ev, unsigned int hwc[],
    260				struct mmcr_regs *mmcr,
    261				struct perf_event *pevents[],
    262				u32 flags __maybe_unused)
    263{
    264	u8 event_index[N_CLASSES][N_COUNTER];
    265	int n_classevent[N_CLASSES];
    266	int i, j, class, tuse;
    267	u32 pmc_inuse = 0, pmc_avail;
    268	u32 mmcr0 = 0, mmcr1 = 0, mmcr2 = 0;
    269	u32 ev, pmc, thresh;
    270
    271	if (n_ev > N_COUNTER)
    272		return -1;
    273
    274	/* First pass: count usage in each class */
    275	for (i = 0; i < N_CLASSES; ++i)
    276		n_classevent[i] = 0;
    277	for (i = 0; i < n_ev; ++i) {
    278		class = mpc7450_classify_event(event[i]);
    279		if (class < 0)
    280			return -1;
    281		j = n_classevent[class]++;
    282		event_index[class][j] = i;
    283	}
    284
    285	/* Second pass: allocate PMCs from most specific event to least */
    286	for (class = N_CLASSES - 1; class >= 0; --class) {
    287		for (i = 0; i < n_classevent[class]; ++i) {
    288			ev = event[event_index[class][i]];
    289			if (class == 4) {
    290				pmc = (ev >> PM_PMC_SH) & PM_PMC_MSK;
    291				if (pmc_inuse & (1 << (pmc - 1)))
    292					return -1;
    293			} else {
    294				/* Find a suitable PMC */
    295				pmc_avail = classmap[class] & ~pmc_inuse;
    296				if (!pmc_avail)
    297					return -1;
    298				pmc = ffs(pmc_avail);
    299			}
    300			pmc_inuse |= 1 << (pmc - 1);
    301
    302			tuse = mpc7450_threshold_use(ev);
    303			if (tuse) {
    304				thresh = (ev >> PM_THRESH_SH) & PM_THRESH_MSK;
    305				mmcr0 |= thresh << 16;
    306				if (tuse == 2 && (ev & PM_THRMULT_MSKS))
    307					mmcr2 = 0x80000000;
    308			}
    309			ev &= pmcsel_mask[pmc - 1];
    310			ev <<= pmcsel_shift[pmc - 1];
    311			if (pmc <= 2)
    312				mmcr0 |= ev;
    313			else
    314				mmcr1 |= ev;
    315			hwc[event_index[class][i]] = pmc - 1;
    316		}
    317	}
    318
    319	if (pmc_inuse & 1)
    320		mmcr0 |= MMCR0_PMC1CE;
    321	if (pmc_inuse & 0x3e)
    322		mmcr0 |= MMCR0_PMCnCE;
    323
    324	/* Return MMCRx values */
    325	mmcr->mmcr0 = mmcr0;
    326	mmcr->mmcr1 = mmcr1;
    327	mmcr->mmcr2 = mmcr2;
    328	/*
    329	 * 32-bit doesn't have an MMCRA and uses SPRN_MMCR2 to define
    330	 * SPRN_MMCRA. So assign mmcra of cpu_hw_events with `mmcr2`
    331	 * value to ensure that any write to this SPRN_MMCRA will
    332	 * use mmcr2 value.
    333	 */
    334	mmcr->mmcra = mmcr2;
    335	return 0;
    336}
    337
    338/*
    339 * Disable counting by a PMC.
    340 * Note that the pmc argument is 0-based here, not 1-based.
    341 */
    342static void mpc7450_disable_pmc(unsigned int pmc, struct mmcr_regs *mmcr)
    343{
    344	if (pmc <= 1)
    345		mmcr->mmcr0 &= ~(pmcsel_mask[pmc] << pmcsel_shift[pmc]);
    346	else
    347		mmcr->mmcr1 &= ~(pmcsel_mask[pmc] << pmcsel_shift[pmc]);
    348}
    349
    350static int mpc7450_generic_events[] = {
    351	[PERF_COUNT_HW_CPU_CYCLES]		= 1,
    352	[PERF_COUNT_HW_INSTRUCTIONS]		= 2,
    353	[PERF_COUNT_HW_CACHE_MISSES]		= 0x217, /* PM_L1_DCACHE_MISS */
    354	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= 0x122, /* PM_BR_CMPL */
    355	[PERF_COUNT_HW_BRANCH_MISSES] 		= 0x41c, /* PM_BR_MPRED */
    356};
    357
    358#define C(x)	PERF_COUNT_HW_CACHE_##x
    359
    360/*
    361 * Table of generalized cache-related events.
    362 * 0 means not supported, -1 means nonsensical, other values
    363 * are event codes.
    364 */
    365static u64 mpc7450_cache_events[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = {
    366	[C(L1D)] = {		/* 	RESULT_ACCESS	RESULT_MISS */
    367		[C(OP_READ)] = {	0,		0x225	},
    368		[C(OP_WRITE)] = {	0,		0x227	},
    369		[C(OP_PREFETCH)] = {	0,		0	},
    370	},
    371	[C(L1I)] = {		/* 	RESULT_ACCESS	RESULT_MISS */
    372		[C(OP_READ)] = {	0x129,		0x115	},
    373		[C(OP_WRITE)] = {	-1,		-1	},
    374		[C(OP_PREFETCH)] = {	0x634,		0	},
    375	},
    376	[C(LL)] = {		/* 	RESULT_ACCESS	RESULT_MISS */
    377		[C(OP_READ)] = {	0,		0	},
    378		[C(OP_WRITE)] = {	0,		0	},
    379		[C(OP_PREFETCH)] = {	0,		0	},
    380	},
    381	[C(DTLB)] = {		/* 	RESULT_ACCESS	RESULT_MISS */
    382		[C(OP_READ)] = {	0,		0x312	},
    383		[C(OP_WRITE)] = {	-1,		-1	},
    384		[C(OP_PREFETCH)] = {	-1,		-1	},
    385	},
    386	[C(ITLB)] = {		/* 	RESULT_ACCESS	RESULT_MISS */
    387		[C(OP_READ)] = {	0,		0x223	},
    388		[C(OP_WRITE)] = {	-1,		-1	},
    389		[C(OP_PREFETCH)] = {	-1,		-1	},
    390	},
    391	[C(BPU)] = {		/* 	RESULT_ACCESS	RESULT_MISS */
    392		[C(OP_READ)] = {	0x122,		0x41c	},
    393		[C(OP_WRITE)] = {	-1,		-1	},
    394		[C(OP_PREFETCH)] = {	-1,		-1	},
    395	},
    396	[C(NODE)] = {		/* 	RESULT_ACCESS	RESULT_MISS */
    397		[C(OP_READ)] = {	-1,		-1	},
    398		[C(OP_WRITE)] = {	-1,		-1	},
    399		[C(OP_PREFETCH)] = {	-1,		-1	},
    400	},
    401};
    402
    403struct power_pmu mpc7450_pmu = {
    404	.name			= "MPC7450 family",
    405	.n_counter		= N_COUNTER,
    406	.max_alternatives	= MAX_ALT,
    407	.add_fields		= 0x00111555ul,
    408	.test_adder		= 0x00301000ul,
    409	.compute_mmcr		= mpc7450_compute_mmcr,
    410	.get_constraint		= mpc7450_get_constraint,
    411	.get_alternatives	= mpc7450_get_alternatives,
    412	.disable_pmc		= mpc7450_disable_pmc,
    413	.n_generic		= ARRAY_SIZE(mpc7450_generic_events),
    414	.generic_events		= mpc7450_generic_events,
    415	.cache_events		= &mpc7450_cache_events,
    416};
    417
    418static int __init init_mpc7450_pmu(void)
    419{
    420	if (!cur_cpu_spec->oprofile_cpu_type ||
    421	    strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc/7450"))
    422		return -ENODEV;
    423
    424	return register_power_pmu(&mpc7450_pmu);
    425}
    426
    427early_initcall(init_mpc7450_pmu);