1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Performance event support - powerpc architecture code
   4 *
   5 * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
   6 */
   7#include <linux/kernel.h>
   8#include <linux/sched.h>
   9#include <linux/sched/clock.h>
  10#include <linux/perf_event.h>
  11#include <linux/percpu.h>
  12#include <linux/hardirq.h>
  13#include <linux/uaccess.h>
  14#include <asm/reg.h>
  15#include <asm/pmc.h>
  16#include <asm/machdep.h>
  17#include <asm/firmware.h>
  18#include <asm/ptrace.h>
  19#include <asm/code-patching.h>
  20#include <asm/hw_irq.h>
  21#include <asm/interrupt.h>
  22
  23#ifdef CONFIG_PPC64
  24#include "internal.h"
  25#endif
  26
  27#define BHRB_MAX_ENTRIES	32
  28#define BHRB_TARGET		0x0000000000000002
  29#define BHRB_PREDICTION		0x0000000000000001
  30#define BHRB_EA			0xFFFFFFFFFFFFFFFCUL
  31
  32struct cpu_hw_events {
  33	int n_events;
  34	int n_percpu;
  35	int disabled;
  36	int n_added;
  37	int n_limited;
  38	u8  pmcs_enabled;
  39	struct perf_event *event[MAX_HWEVENTS];
  40	u64 events[MAX_HWEVENTS];
  41	unsigned int flags[MAX_HWEVENTS];
  42	struct mmcr_regs mmcr;
  43	struct perf_event *limited_counter[MAX_LIMITED_HWCOUNTERS];
  44	u8  limited_hwidx[MAX_LIMITED_HWCOUNTERS];
  45	u64 alternatives[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES];
  46	unsigned long amasks[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES];
  47	unsigned long avalues[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES];
  48
  49	unsigned int txn_flags;
  50	int n_txn_start;
  51
  52	/* BHRB bits */
  53	u64				bhrb_filter;	/* BHRB HW branch filter */
  54	unsigned int			bhrb_users;
  55	void				*bhrb_context;
  56	struct	perf_branch_stack	bhrb_stack;
  57	struct	perf_branch_entry	bhrb_entries[BHRB_MAX_ENTRIES];
  58	u64				ic_init;
  59
  60	/* Store the PMC values */
  61	unsigned long pmcs[MAX_HWEVENTS];
  62};
  63
  64static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
  65
  66static struct power_pmu *ppmu;
  67
  68/*
  69 * Normally, to ignore kernel events we set the FCS (freeze counters
  70 * in supervisor mode) bit in MMCR0, but if the kernel runs with the
  71 * hypervisor bit set in the MSR, or if we are running on a processor
  72 * where the hypervisor bit is forced to 1 (as on Apple G5 processors),
  73 * then we need to use the FCHV bit to ignore kernel events.
  74 */
  75static unsigned int freeze_events_kernel = MMCR0_FCS;
  76
  77/*
  78 * 32-bit doesn't have MMCRA but does have an MMCR2,
  79 * and a few other names are different.
  80 * Also 32-bit doesn't have MMCR3, SIER2 and SIER3.
  81 * Define them as zero knowing that any code path accessing
  82 * these registers (via mtspr/mfspr) are done under ppmu flag
  83 * check for PPMU_ARCH_31 and we will not enter that code path
  84 * for 32-bit.
  85 */
  86#ifdef CONFIG_PPC32
  87
  88#define MMCR0_FCHV		0
  89#define MMCR0_PMCjCE		MMCR0_PMCnCE
  90#define MMCR0_FC56		0
  91#define MMCR0_PMAO		0
  92#define MMCR0_EBE		0
  93#define MMCR0_BHRBA		0
  94#define MMCR0_PMCC		0
  95#define MMCR0_PMCC_U6		0
  96
  97#define SPRN_MMCRA		SPRN_MMCR2
  98#define SPRN_MMCR3		0
  99#define SPRN_SIER2		0
 100#define SPRN_SIER3		0
 101#define MMCRA_SAMPLE_ENABLE	0
 102#define MMCRA_BHRB_DISABLE     0
 103#define MMCR0_PMCCEXT		0
 104
 105static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
 106{
 107	return 0;
 108}
 109static inline void perf_get_data_addr(struct perf_event *event, struct pt_regs *regs, u64 *addrp) { }
 110static inline u32 perf_get_misc_flags(struct pt_regs *regs)
 111{
 112	return 0;
 113}
 114static inline void perf_read_regs(struct pt_regs *regs)
 115{
 116	regs->result = 0;
 117}
 118
 119static inline int siar_valid(struct pt_regs *regs)
 120{
 121	return 1;
 122}
 123
 124static bool is_ebb_event(struct perf_event *event) { return false; }
 125static int ebb_event_check(struct perf_event *event) { return 0; }
 126static void ebb_event_add(struct perf_event *event) { }
 127static void ebb_switch_out(unsigned long mmcr0) { }
 128static unsigned long ebb_switch_in(bool ebb, struct cpu_hw_events *cpuhw)
 129{
 130	return cpuhw->mmcr.mmcr0;
 131}
 132
 133static inline void power_pmu_bhrb_enable(struct perf_event *event) {}
 134static inline void power_pmu_bhrb_disable(struct perf_event *event) {}
 135static void power_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in) {}
 136static inline void power_pmu_bhrb_read(struct perf_event *event, struct cpu_hw_events *cpuhw) {}
 137static void pmao_restore_workaround(bool ebb) { }
 138#endif /* CONFIG_PPC32 */
 139
 140bool is_sier_available(void)
 141{
 142	if (!ppmu)
 143		return false;
 144
 145	if (ppmu->flags & PPMU_HAS_SIER)
 146		return true;
 147
 148	return false;
 149}
 150
 151/*
 152 * Return PMC value corresponding to the
 153 * index passed.
 154 */
 155unsigned long get_pmcs_ext_regs(int idx)
 156{
 157	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 158
 159	return cpuhw->pmcs[idx];
 160}
 161
 162static bool regs_use_siar(struct pt_regs *regs)
 163{
 164	/*
 165	 * When we take a performance monitor exception the regs are setup
 166	 * using perf_read_regs() which overloads some fields, in particular
 167	 * regs->result to tell us whether to use SIAR.
 168	 *
 169	 * However if the regs are from another exception, eg. a syscall, then
 170	 * they have not been setup using perf_read_regs() and so regs->result
 171	 * is something random.
 172	 */
 173	return ((TRAP(regs) == INTERRUPT_PERFMON) && regs->result);
 174}
 175
 176/*
 177 * Things that are specific to 64-bit implementations.
 178 */
 179#ifdef CONFIG_PPC64
 180
 181static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
 182{
 183	unsigned long mmcra = regs->dsisr;
 184
 185	if ((ppmu->flags & PPMU_HAS_SSLOT) && (mmcra & MMCRA_SAMPLE_ENABLE)) {
 186		unsigned long slot = (mmcra & MMCRA_SLOT) >> MMCRA_SLOT_SHIFT;
 187		if (slot > 1)
 188			return 4 * (slot - 1);
 189	}
 190
 191	return 0;
 192}
 193
 194/*
 195 * The user wants a data address recorded.
 196 * If we're not doing instruction sampling, give them the SDAR
 197 * (sampled data address).  If we are doing instruction sampling, then
 198 * only give them the SDAR if it corresponds to the instruction
 199 * pointed to by SIAR; this is indicated by the [POWER6_]MMCRA_SDSYNC, the
 200 * [POWER7P_]MMCRA_SDAR_VALID bit in MMCRA, or the SDAR_VALID bit in SIER.
 201 */
 202static inline void perf_get_data_addr(struct perf_event *event, struct pt_regs *regs, u64 *addrp)
 203{
 204	unsigned long mmcra = regs->dsisr;
 205	bool sdar_valid;
 206
 207	if (ppmu->flags & PPMU_HAS_SIER)
 208		sdar_valid = regs->dar & SIER_SDAR_VALID;
 209	else {
 210		unsigned long sdsync;
 211
 212		if (ppmu->flags & PPMU_SIAR_VALID)
 213			sdsync = POWER7P_MMCRA_SDAR_VALID;
 214		else if (ppmu->flags & PPMU_ALT_SIPR)
 215			sdsync = POWER6_MMCRA_SDSYNC;
 216		else if (ppmu->flags & PPMU_NO_SIAR)
 217			sdsync = MMCRA_SAMPLE_ENABLE;
 218		else
 219			sdsync = MMCRA_SDSYNC;
 220
 221		sdar_valid = mmcra & sdsync;
 222	}
 223
 224	if (!(mmcra & MMCRA_SAMPLE_ENABLE) || sdar_valid)
 225		*addrp = mfspr(SPRN_SDAR);
 226
 227	if (is_kernel_addr(mfspr(SPRN_SDAR)) && event->attr.exclude_kernel)
 228		*addrp = 0;
 229}
 230
 231static bool regs_sihv(struct pt_regs *regs)
 232{
 233	unsigned long sihv = MMCRA_SIHV;
 234
 235	if (ppmu->flags & PPMU_HAS_SIER)
 236		return !!(regs->dar & SIER_SIHV);
 237
 238	if (ppmu->flags & PPMU_ALT_SIPR)
 239		sihv = POWER6_MMCRA_SIHV;
 240
 241	return !!(regs->dsisr & sihv);
 242}
 243
 244static bool regs_sipr(struct pt_regs *regs)
 245{
 246	unsigned long sipr = MMCRA_SIPR;
 247
 248	if (ppmu->flags & PPMU_HAS_SIER)
 249		return !!(regs->dar & SIER_SIPR);
 250
 251	if (ppmu->flags & PPMU_ALT_SIPR)
 252		sipr = POWER6_MMCRA_SIPR;
 253
 254	return !!(regs->dsisr & sipr);
 255}
 256
 257static inline u32 perf_flags_from_msr(struct pt_regs *regs)
 258{
 259	if (regs->msr & MSR_PR)
 260		return PERF_RECORD_MISC_USER;
 261	if ((regs->msr & MSR_HV) && freeze_events_kernel != MMCR0_FCHV)
 262		return PERF_RECORD_MISC_HYPERVISOR;
 263	return PERF_RECORD_MISC_KERNEL;
 264}
 265
 266static inline u32 perf_get_misc_flags(struct pt_regs *regs)
 267{
 268	bool use_siar = regs_use_siar(regs);
 269	unsigned long mmcra = regs->dsisr;
 270	int marked = mmcra & MMCRA_SAMPLE_ENABLE;
 271
 272	if (!use_siar)
 273		return perf_flags_from_msr(regs);
 274
 275	/*
 276	 * Check the address in SIAR to identify the
 277	 * privilege levels since the SIER[MSR_HV, MSR_PR]
 278	 * bits are not set for marked events in power10
 279	 * DD1.
 280	 */
 281	if (marked && (ppmu->flags & PPMU_P10_DD1)) {
 282		unsigned long siar = mfspr(SPRN_SIAR);
 283		if (siar) {
 284			if (is_kernel_addr(siar))
 285				return PERF_RECORD_MISC_KERNEL;
 286			return PERF_RECORD_MISC_USER;
 287		} else {
 288			if (is_kernel_addr(regs->nip))
 289				return PERF_RECORD_MISC_KERNEL;
 290			return PERF_RECORD_MISC_USER;
 291		}
 292	}
 293
 294	/*
 295	 * If we don't have flags in MMCRA, rather than using
 296	 * the MSR, we intuit the flags from the address in
 297	 * SIAR which should give slightly more reliable
 298	 * results
 299	 */
 300	if (ppmu->flags & PPMU_NO_SIPR) {
 301		unsigned long siar = mfspr(SPRN_SIAR);
 302		if (is_kernel_addr(siar))
 303			return PERF_RECORD_MISC_KERNEL;
 304		return PERF_RECORD_MISC_USER;
 305	}
 306
 307	/* PR has priority over HV, so order below is important */
 308	if (regs_sipr(regs))
 309		return PERF_RECORD_MISC_USER;
 310
 311	if (regs_sihv(regs) && (freeze_events_kernel != MMCR0_FCHV))
 312		return PERF_RECORD_MISC_HYPERVISOR;
 313
 314	return PERF_RECORD_MISC_KERNEL;
 315}
 316
 317/*
 318 * Overload regs->dsisr to store MMCRA so we only need to read it once
 319 * on each interrupt.
 320 * Overload regs->dar to store SIER if we have it.
 321 * Overload regs->result to specify whether we should use the MSR (result
 322 * is zero) or the SIAR (result is non zero).
 323 */
 324static inline void perf_read_regs(struct pt_regs *regs)
 325{
 326	unsigned long mmcra = mfspr(SPRN_MMCRA);
 327	int marked = mmcra & MMCRA_SAMPLE_ENABLE;
 328	int use_siar;
 329
 330	regs->dsisr = mmcra;
 331
 332	if (ppmu->flags & PPMU_HAS_SIER)
 333		regs->dar = mfspr(SPRN_SIER);
 334
 335	/*
 336	 * If this isn't a PMU exception (eg a software event) the SIAR is
 337	 * not valid. Use pt_regs.
 338	 *
 339	 * If it is a marked event use the SIAR.
 340	 *
 341	 * If the PMU doesn't update the SIAR for non marked events use
 342	 * pt_regs.
 343	 *
 344	 * If regs is a kernel interrupt, always use SIAR. Some PMUs have an
 345	 * issue with regs_sipr not being in synch with SIAR in interrupt entry
 346	 * and return sequences, which can result in regs_sipr being true for
 347	 * kernel interrupts and SIAR, which has the effect of causing samples
 348	 * to pile up at mtmsrd MSR[EE] 0->1 or pending irq replay around
 349	 * interrupt entry/exit.
 350	 *
 351	 * If the PMU has HV/PR flags then check to see if they
 352	 * place the exception in userspace. If so, use pt_regs. In
 353	 * continuous sampling mode the SIAR and the PMU exception are
 354	 * not synchronised, so they may be many instructions apart.
 355	 * This can result in confusing backtraces. We still want
 356	 * hypervisor samples as well as samples in the kernel with
 357	 * interrupts off hence the userspace check.
 358	 */
 359	if (TRAP(regs) != INTERRUPT_PERFMON)
 360		use_siar = 0;
 361	else if ((ppmu->flags & PPMU_NO_SIAR))
 362		use_siar = 0;
 363	else if (marked)
 364		use_siar = 1;
 365	else if ((ppmu->flags & PPMU_NO_CONT_SAMPLING))
 366		use_siar = 0;
 367	else if (!user_mode(regs))
 368		use_siar = 1;
 369	else if (!(ppmu->flags & PPMU_NO_SIPR) && regs_sipr(regs))
 370		use_siar = 0;
 371	else
 372		use_siar = 1;
 373
 374	regs->result = use_siar;
 375}
 376
 377/*
 378 * On processors like P7+ that have the SIAR-Valid bit, marked instructions
 379 * must be sampled only if the SIAR-valid bit is set.
 380 *
 381 * For unmarked instructions and for processors that don't have the SIAR-Valid
 382 * bit, assume that SIAR is valid.
 383 */
 384static inline int siar_valid(struct pt_regs *regs)
 385{
 386	unsigned long mmcra = regs->dsisr;
 387	int marked = mmcra & MMCRA_SAMPLE_ENABLE;
 388
 389	if (marked) {
 390		/*
 391		 * SIER[SIAR_VALID] is not set for some
 392		 * marked events on power10 DD1, so drop
 393		 * the check for SIER[SIAR_VALID] and return true.
 394		 */
 395		if (ppmu->flags & PPMU_P10_DD1)
 396			return 0x1;
 397		else if (ppmu->flags & PPMU_HAS_SIER)
 398			return regs->dar & SIER_SIAR_VALID;
 399
 400		if (ppmu->flags & PPMU_SIAR_VALID)
 401			return mmcra & POWER7P_MMCRA_SIAR_VALID;
 402	}
 403
 404	return 1;
 405}
 406
 407
 408/* Reset all possible BHRB entries */
 409static void power_pmu_bhrb_reset(void)
 410{
 411	asm volatile(PPC_CLRBHRB);
 412}
 413
 414static void power_pmu_bhrb_enable(struct perf_event *event)
 415{
 416	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 417
 418	if (!ppmu->bhrb_nr)
 419		return;
 420
 421	/* Clear BHRB if we changed task context to avoid data leaks */
 422	if (event->ctx->task && cpuhw->bhrb_context != event->ctx) {
 423		power_pmu_bhrb_reset();
 424		cpuhw->bhrb_context = event->ctx;
 425	}
 426	cpuhw->bhrb_users++;
 427	perf_sched_cb_inc(event->pmu);
 428}
 429
 430static void power_pmu_bhrb_disable(struct perf_event *event)
 431{
 432	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 433
 434	if (!ppmu->bhrb_nr)
 435		return;
 436
 437	WARN_ON_ONCE(!cpuhw->bhrb_users);
 438	cpuhw->bhrb_users--;
 439	perf_sched_cb_dec(event->pmu);
 440
 441	if (!cpuhw->disabled && !cpuhw->bhrb_users) {
 442		/* BHRB cannot be turned off when other
 443		 * events are active on the PMU.
 444		 */
 445
 446		/* avoid stale pointer */
 447		cpuhw->bhrb_context = NULL;
 448	}
 449}
 450
 451/* Called from ctxsw to prevent one process's branch entries to
 452 * mingle with the other process's entries during context switch.
 453 */
 454static void power_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
 455{
 456	if (!ppmu->bhrb_nr)
 457		return;
 458
 459	if (sched_in)
 460		power_pmu_bhrb_reset();
 461}
 462/* Calculate the to address for a branch */
 463static __u64 power_pmu_bhrb_to(u64 addr)
 464{
 465	unsigned int instr;
 466	__u64 target;
 467
 468	if (is_kernel_addr(addr)) {
 469		if (copy_from_kernel_nofault(&instr, (void *)addr,
 470				sizeof(instr)))
 471			return 0;
 472
 473		return branch_target(&instr);
 474	}
 475
 476	/* Userspace: need copy instruction here then translate it */
 477	if (copy_from_user_nofault(&instr, (unsigned int __user *)addr,
 478			sizeof(instr)))
 479		return 0;
 480
 481	target = branch_target(&instr);
 482	if ((!target) || (instr & BRANCH_ABSOLUTE))
 483		return target;
 484
 485	/* Translate relative branch target from kernel to user address */
 486	return target - (unsigned long)&instr + addr;
 487}
 488
 489/* Processing BHRB entries */
 490static void power_pmu_bhrb_read(struct perf_event *event, struct cpu_hw_events *cpuhw)
 491{
 492	u64 val;
 493	u64 addr;
 494	int r_index, u_index, pred;
 495
 496	r_index = 0;
 497	u_index = 0;
 498	while (r_index < ppmu->bhrb_nr) {
 499		/* Assembly read function */
 500		val = read_bhrb(r_index++);
 501		if (!val)
 502			/* Terminal marker: End of valid BHRB entries */
 503			break;
 504		else {
 505			addr = val & BHRB_EA;
 506			pred = val & BHRB_PREDICTION;
 507
 508			if (!addr)
 509				/* invalid entry */
 510				continue;
 511
 512			/*
 513			 * BHRB rolling buffer could very much contain the kernel
 514			 * addresses at this point. Check the privileges before
 515			 * exporting it to userspace (avoid exposure of regions
 516			 * where we could have speculative execution)
 517			 * Incase of ISA v3.1, BHRB will capture only user-space
 518			 * addresses, hence include a check before filtering code
 519			 */
 520			if (!(ppmu->flags & PPMU_ARCH_31) &&
 521			    is_kernel_addr(addr) && event->attr.exclude_kernel)
 522				continue;
 523
 524			/* Branches are read most recent first (ie. mfbhrb 0 is
 525			 * the most recent branch).
 526			 * There are two types of valid entries:
 527			 * 1) a target entry which is the to address of a
 528			 *    computed goto like a blr,bctr,btar.  The next
 529			 *    entry read from the bhrb will be branch
 530			 *    corresponding to this target (ie. the actual
 531			 *    blr/bctr/btar instruction).
 532			 * 2) a from address which is an actual branch.  If a
 533			 *    target entry proceeds this, then this is the
 534			 *    matching branch for that target.  If this is not
 535			 *    following a target entry, then this is a branch
 536			 *    where the target is given as an immediate field
 537			 *    in the instruction (ie. an i or b form branch).
 538			 *    In this case we need to read the instruction from
 539			 *    memory to determine the target/to address.
 540			 */
 541
 542			if (val & BHRB_TARGET) {
 543				/* Target branches use two entries
 544				 * (ie. computed gotos/XL form)
 545				 */
 546				cpuhw->bhrb_entries[u_index].to = addr;
 547				cpuhw->bhrb_entries[u_index].mispred = pred;
 548				cpuhw->bhrb_entries[u_index].predicted = ~pred;
 549
 550				/* Get from address in next entry */
 551				val = read_bhrb(r_index++);
 552				addr = val & BHRB_EA;
 553				if (val & BHRB_TARGET) {
 554					/* Shouldn't have two targets in a
 555					   row.. Reset index and try again */
 556					r_index--;
 557					addr = 0;
 558				}
 559				cpuhw->bhrb_entries[u_index].from = addr;
 560			} else {
 561				/* Branches to immediate field 
 562				   (ie I or B form) */
 563				cpuhw->bhrb_entries[u_index].from = addr;
 564				cpuhw->bhrb_entries[u_index].to =
 565					power_pmu_bhrb_to(addr);
 566				cpuhw->bhrb_entries[u_index].mispred = pred;
 567				cpuhw->bhrb_entries[u_index].predicted = ~pred;
 568			}
 569			u_index++;
 570
 571		}
 572	}
 573	cpuhw->bhrb_stack.nr = u_index;
 574	cpuhw->bhrb_stack.hw_idx = -1ULL;
 575	return;
 576}
 577
 578static bool is_ebb_event(struct perf_event *event)
 579{
 580	/*
 581	 * This could be a per-PMU callback, but we'd rather avoid the cost. We
 582	 * check that the PMU supports EBB, meaning those that don't can still
 583	 * use bit 63 of the event code for something else if they wish.
 584	 */
 585	return (ppmu->flags & PPMU_ARCH_207S) &&
 586	       ((event->attr.config >> PERF_EVENT_CONFIG_EBB_SHIFT) & 1);
 587}
 588
 589static int ebb_event_check(struct perf_event *event)
 590{
 591	struct perf_event *leader = event->group_leader;
 592
 593	/* Event and group leader must agree on EBB */
 594	if (is_ebb_event(leader) != is_ebb_event(event))
 595		return -EINVAL;
 596
 597	if (is_ebb_event(event)) {
 598		if (!(event->attach_state & PERF_ATTACH_TASK))
 599			return -EINVAL;
 600
 601		if (!leader->attr.pinned || !leader->attr.exclusive)
 602			return -EINVAL;
 603
 604		if (event->attr.freq ||
 605		    event->attr.inherit ||
 606		    event->attr.sample_type ||
 607		    event->attr.sample_period ||
 608		    event->attr.enable_on_exec)
 609			return -EINVAL;
 610	}
 611
 612	return 0;
 613}
 614
 615static void ebb_event_add(struct perf_event *event)
 616{
 617	if (!is_ebb_event(event) || current->thread.used_ebb)
 618		return;
 619
 620	/*
 621	 * IFF this is the first time we've added an EBB event, set
 622	 * PMXE in the user MMCR0 so we can detect when it's cleared by
 623	 * userspace. We need this so that we can context switch while
 624	 * userspace is in the EBB handler (where PMXE is 0).
 625	 */
 626	current->thread.used_ebb = 1;
 627	current->thread.mmcr0 |= MMCR0_PMXE;
 628}
 629
 630static void ebb_switch_out(unsigned long mmcr0)
 631{
 632	if (!(mmcr0 & MMCR0_EBE))
 633		return;
 634
 635	current->thread.siar  = mfspr(SPRN_SIAR);
 636	current->thread.sier  = mfspr(SPRN_SIER);
 637	current->thread.sdar  = mfspr(SPRN_SDAR);
 638	current->thread.mmcr0 = mmcr0 & MMCR0_USER_MASK;
 639	current->thread.mmcr2 = mfspr(SPRN_MMCR2) & MMCR2_USER_MASK;
 640	if (ppmu->flags & PPMU_ARCH_31) {
 641		current->thread.mmcr3 = mfspr(SPRN_MMCR3);
 642		current->thread.sier2 = mfspr(SPRN_SIER2);
 643		current->thread.sier3 = mfspr(SPRN_SIER3);
 644	}
 645}
 646
 647static unsigned long ebb_switch_in(bool ebb, struct cpu_hw_events *cpuhw)
 648{
 649	unsigned long mmcr0 = cpuhw->mmcr.mmcr0;
 650
 651	if (!ebb)
 652		goto out;
 653
 654	/* Enable EBB and read/write to all 6 PMCs and BHRB for userspace */
 655	mmcr0 |= MMCR0_EBE | MMCR0_BHRBA | MMCR0_PMCC_U6;
 656
 657	/*
 658	 * Add any bits from the user MMCR0, FC or PMAO. This is compatible
 659	 * with pmao_restore_workaround() because we may add PMAO but we never
 660	 * clear it here.
 661	 */
 662	mmcr0 |= current->thread.mmcr0;
 663
 664	/*
 665	 * Be careful not to set PMXE if userspace had it cleared. This is also
 666	 * compatible with pmao_restore_workaround() because it has already
 667	 * cleared PMXE and we leave PMAO alone.
 668	 */
 669	if (!(current->thread.mmcr0 & MMCR0_PMXE))
 670		mmcr0 &= ~MMCR0_PMXE;
 671
 672	mtspr(SPRN_SIAR, current->thread.siar);
 673	mtspr(SPRN_SIER, current->thread.sier);
 674	mtspr(SPRN_SDAR, current->thread.sdar);
 675
 676	/*
 677	 * Merge the kernel & user values of MMCR2. The semantics we implement
 678	 * are that the user MMCR2 can set bits, ie. cause counters to freeze,
 679	 * but not clear bits. If a task wants to be able to clear bits, ie.
 680	 * unfreeze counters, it should not set exclude_xxx in its events and
 681	 * instead manage the MMCR2 entirely by itself.
 682	 */
 683	mtspr(SPRN_MMCR2, cpuhw->mmcr.mmcr2 | current->thread.mmcr2);
 684
 685	if (ppmu->flags & PPMU_ARCH_31) {
 686		mtspr(SPRN_MMCR3, current->thread.mmcr3);
 687		mtspr(SPRN_SIER2, current->thread.sier2);
 688		mtspr(SPRN_SIER3, current->thread.sier3);
 689	}
 690out:
 691	return mmcr0;
 692}
 693
 694static void pmao_restore_workaround(bool ebb)
 695{
 696	unsigned pmcs[6];
 697
 698	if (!cpu_has_feature(CPU_FTR_PMAO_BUG))
 699		return;
 700
 701	/*
 702	 * On POWER8E there is a hardware defect which affects the PMU context
 703	 * switch logic, ie. power_pmu_disable/enable().
 704	 *
 705	 * When a counter overflows PMXE is cleared and FC/PMAO is set in MMCR0
 706	 * by the hardware. Sometime later the actual PMU exception is
 707	 * delivered.
 708	 *
 709	 * If we context switch, or simply disable/enable, the PMU prior to the
 710	 * exception arriving, the exception will be lost when we clear PMAO.
 711	 *
 712	 * When we reenable the PMU, we will write the saved MMCR0 with PMAO
 713	 * set, and this _should_ generate an exception. However because of the
 714	 * defect no exception is generated when we write PMAO, and we get
 715	 * stuck with no counters counting but no exception delivered.
 716	 *
 717	 * The workaround is to detect this case and tweak the hardware to
 718	 * create another pending PMU exception.
 719	 *
 720	 * We do that by setting up PMC6 (cycles) for an imminent overflow and
 721	 * enabling the PMU. That causes a new exception to be generated in the
 722	 * chip, but we don't take it yet because we have interrupts hard
 723	 * disabled. We then write back the PMU state as we want it to be seen
 724	 * by the exception handler. When we reenable interrupts the exception
 725	 * handler will be called and see the correct state.
 726	 *
 727	 * The logic is the same for EBB, except that the exception is gated by
 728	 * us having interrupts hard disabled as well as the fact that we are
 729	 * not in userspace. The exception is finally delivered when we return
 730	 * to userspace.
 731	 */
 732
 733	/* Only if PMAO is set and PMAO_SYNC is clear */
 734	if ((current->thread.mmcr0 & (MMCR0_PMAO | MMCR0_PMAO_SYNC)) != MMCR0_PMAO)
 735		return;
 736
 737	/* If we're doing EBB, only if BESCR[GE] is set */
 738	if (ebb && !(current->thread.bescr & BESCR_GE))
 739		return;
 740
 741	/*
 742	 * We are already soft-disabled in power_pmu_enable(). We need to hard
 743	 * disable to actually prevent the PMU exception from firing.
 744	 */
 745	hard_irq_disable();
 746
 747	/*
 748	 * This is a bit gross, but we know we're on POWER8E and have 6 PMCs.
 749	 * Using read/write_pmc() in a for loop adds 12 function calls and
 750	 * almost doubles our code size.
 751	 */
 752	pmcs[0] = mfspr(SPRN_PMC1);
 753	pmcs[1] = mfspr(SPRN_PMC2);
 754	pmcs[2] = mfspr(SPRN_PMC3);
 755	pmcs[3] = mfspr(SPRN_PMC4);
 756	pmcs[4] = mfspr(SPRN_PMC5);
 757	pmcs[5] = mfspr(SPRN_PMC6);
 758
 759	/* Ensure all freeze bits are unset */
 760	mtspr(SPRN_MMCR2, 0);
 761
 762	/* Set up PMC6 to overflow in one cycle */
 763	mtspr(SPRN_PMC6, 0x7FFFFFFE);
 764
 765	/* Enable exceptions and unfreeze PMC6 */
 766	mtspr(SPRN_MMCR0, MMCR0_PMXE | MMCR0_PMCjCE | MMCR0_PMAO);
 767
 768	/* Now we need to refreeze and restore the PMCs */
 769	mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMAO);
 770
 771	mtspr(SPRN_PMC1, pmcs[0]);
 772	mtspr(SPRN_PMC2, pmcs[1]);
 773	mtspr(SPRN_PMC3, pmcs[2]);
 774	mtspr(SPRN_PMC4, pmcs[3]);
 775	mtspr(SPRN_PMC5, pmcs[4]);
 776	mtspr(SPRN_PMC6, pmcs[5]);
 777}
 778
 779/*
 780 * If the perf subsystem wants performance monitor interrupts as soon as
 781 * possible (e.g., to sample the instruction address and stack chain),
 782 * this should return true. The IRQ masking code can then enable MSR[EE]
 783 * in some places (e.g., interrupt handlers) that allows PMI interrupts
 784 * through to improve accuracy of profiles, at the cost of some performance.
 785 *
 786 * The PMU counters can be enabled by other means (e.g., sysfs raw SPR
 787 * access), but in that case there is no need for prompt PMI handling.
 788 *
 789 * This currently returns true if any perf counter is being used. It
 790 * could possibly return false if only events are being counted rather than
 791 * samples being taken, but for now this is good enough.
 792 */
 793bool power_pmu_wants_prompt_pmi(void)
 794{
 795	struct cpu_hw_events *cpuhw;
 796
 797	/*
 798	 * This could simply test local_paca->pmcregs_in_use if that were not
 799	 * under ifdef KVM.
 800	 */
 801	if (!ppmu)
 802		return false;
 803
 804	cpuhw = this_cpu_ptr(&cpu_hw_events);
 805	return cpuhw->n_events;
 806}
 807#endif /* CONFIG_PPC64 */
 808
 809static void perf_event_interrupt(struct pt_regs *regs);
 810
 811/*
 812 * Read one performance monitor counter (PMC).
 813 */
 814static unsigned long read_pmc(int idx)
 815{
 816	unsigned long val;
 817
 818	switch (idx) {
 819	case 1:
 820		val = mfspr(SPRN_PMC1);
 821		break;
 822	case 2:
 823		val = mfspr(SPRN_PMC2);
 824		break;
 825	case 3:
 826		val = mfspr(SPRN_PMC3);
 827		break;
 828	case 4:
 829		val = mfspr(SPRN_PMC4);
 830		break;
 831	case 5:
 832		val = mfspr(SPRN_PMC5);
 833		break;
 834	case 6:
 835		val = mfspr(SPRN_PMC6);
 836		break;
 837#ifdef CONFIG_PPC64
 838	case 7:
 839		val = mfspr(SPRN_PMC7);
 840		break;
 841	case 8:
 842		val = mfspr(SPRN_PMC8);
 843		break;
 844#endif /* CONFIG_PPC64 */
 845	default:
 846		printk(KERN_ERR "oops trying to read PMC%d\n", idx);
 847		val = 0;
 848	}
 849	return val;
 850}
 851
 852/*
 853 * Write one PMC.
 854 */
 855static void write_pmc(int idx, unsigned long val)
 856{
 857	switch (idx) {
 858	case 1:
 859		mtspr(SPRN_PMC1, val);
 860		break;
 861	case 2:
 862		mtspr(SPRN_PMC2, val);
 863		break;
 864	case 3:
 865		mtspr(SPRN_PMC3, val);
 866		break;
 867	case 4:
 868		mtspr(SPRN_PMC4, val);
 869		break;
 870	case 5:
 871		mtspr(SPRN_PMC5, val);
 872		break;
 873	case 6:
 874		mtspr(SPRN_PMC6, val);
 875		break;
 876#ifdef CONFIG_PPC64
 877	case 7:
 878		mtspr(SPRN_PMC7, val);
 879		break;
 880	case 8:
 881		mtspr(SPRN_PMC8, val);
 882		break;
 883#endif /* CONFIG_PPC64 */
 884	default:
 885		printk(KERN_ERR "oops trying to write PMC%d\n", idx);
 886	}
 887}
 888
 889static int any_pmc_overflown(struct cpu_hw_events *cpuhw)
 890{
 891	int i, idx;
 892
 893	for (i = 0; i < cpuhw->n_events; i++) {
 894		idx = cpuhw->event[i]->hw.idx;
 895		if ((idx) && ((int)read_pmc(idx) < 0))
 896			return idx;
 897	}
 898
 899	return 0;
 900}
 901
 902/* Called from sysrq_handle_showregs() */
 903void perf_event_print_debug(void)
 904{
 905	unsigned long sdar, sier, flags;
 906	u32 pmcs[MAX_HWEVENTS];
 907	int i;
 908
 909	if (!ppmu) {
 910		pr_info("Performance monitor hardware not registered.\n");
 911		return;
 912	}
 913
 914	if (!ppmu->n_counter)
 915		return;
 916
 917	local_irq_save(flags);
 918
 919	pr_info("CPU: %d PMU registers, ppmu = %s n_counters = %d",
 920		 smp_processor_id(), ppmu->name, ppmu->n_counter);
 921
 922	for (i = 0; i < ppmu->n_counter; i++)
 923		pmcs[i] = read_pmc(i + 1);
 924
 925	for (; i < MAX_HWEVENTS; i++)
 926		pmcs[i] = 0xdeadbeef;
 927
 928	pr_info("PMC1:  %08x PMC2: %08x PMC3: %08x PMC4: %08x\n",
 929		 pmcs[0], pmcs[1], pmcs[2], pmcs[3]);
 930
 931	if (ppmu->n_counter > 4)
 932		pr_info("PMC5:  %08x PMC6: %08x PMC7: %08x PMC8: %08x\n",
 933			 pmcs[4], pmcs[5], pmcs[6], pmcs[7]);
 934
 935	pr_info("MMCR0: %016lx MMCR1: %016lx MMCRA: %016lx\n",
 936		mfspr(SPRN_MMCR0), mfspr(SPRN_MMCR1), mfspr(SPRN_MMCRA));
 937
 938	sdar = sier = 0;
 939#ifdef CONFIG_PPC64
 940	sdar = mfspr(SPRN_SDAR);
 941
 942	if (ppmu->flags & PPMU_HAS_SIER)
 943		sier = mfspr(SPRN_SIER);
 944
 945	if (ppmu->flags & PPMU_ARCH_207S) {
 946		pr_info("MMCR2: %016lx EBBHR: %016lx\n",
 947			mfspr(SPRN_MMCR2), mfspr(SPRN_EBBHR));
 948		pr_info("EBBRR: %016lx BESCR: %016lx\n",
 949			mfspr(SPRN_EBBRR), mfspr(SPRN_BESCR));
 950	}
 951
 952	if (ppmu->flags & PPMU_ARCH_31) {
 953		pr_info("MMCR3: %016lx SIER2: %016lx SIER3: %016lx\n",
 954			mfspr(SPRN_MMCR3), mfspr(SPRN_SIER2), mfspr(SPRN_SIER3));
 955	}
 956#endif
 957	pr_info("SIAR:  %016lx SDAR:  %016lx SIER:  %016lx\n",
 958		mfspr(SPRN_SIAR), sdar, sier);
 959
 960	local_irq_restore(flags);
 961}
 962
 963/*
 964 * Check if a set of events can all go on the PMU at once.
 965 * If they can't, this will look at alternative codes for the events
 966 * and see if any combination of alternative codes is feasible.
 967 * The feasible set is returned in event_id[].
 968 */
 969static int power_check_constraints(struct cpu_hw_events *cpuhw,
 970				   u64 event_id[], unsigned int cflags[],
 971				   int n_ev, struct perf_event **event)
 972{
 973	unsigned long mask, value, nv;
 974	unsigned long smasks[MAX_HWEVENTS], svalues[MAX_HWEVENTS];
 975	int n_alt[MAX_HWEVENTS], choice[MAX_HWEVENTS];
 976	int i, j;
 977	unsigned long addf = ppmu->add_fields;
 978	unsigned long tadd = ppmu->test_adder;
 979	unsigned long grp_mask = ppmu->group_constraint_mask;
 980	unsigned long grp_val = ppmu->group_constraint_val;
 981
 982	if (n_ev > ppmu->n_counter)
 983		return -1;
 984
 985	/* First see if the events will go on as-is */
 986	for (i = 0; i < n_ev; ++i) {
 987		if ((cflags[i] & PPMU_LIMITED_PMC_REQD)
 988		    && !ppmu->limited_pmc_event(event_id[i])) {
 989			ppmu->get_alternatives(event_id[i], cflags[i],
 990					       cpuhw->alternatives[i]);
 991			event_id[i] = cpuhw->alternatives[i][0];
 992		}
 993		if (ppmu->get_constraint(event_id[i], &cpuhw->amasks[i][0],
 994					 &cpuhw->avalues[i][0], event[i]->attr.config1))
 995			return -1;
 996	}
 997	value = mask = 0;
 998	for (i = 0; i < n_ev; ++i) {
 999		nv = (value | cpuhw->avalues[i][0]) +
1000			(value & cpuhw->avalues[i][0] & addf);
1001
1002		if (((((nv + tadd) ^ value) & mask) & (~grp_mask)) != 0)
1003			break;
1004
1005		if (((((nv + tadd) ^ cpuhw->avalues[i][0]) & cpuhw->amasks[i][0])
1006			& (~grp_mask)) != 0)
1007			break;
1008
1009		value = nv;
1010		mask |= cpuhw->amasks[i][0];
1011	}
1012	if (i == n_ev) {
1013		if ((value & mask & grp_mask) != (mask & grp_val))
1014			return -1;
1015		else
1016			return 0;	/* all OK */
1017	}
1018
1019	/* doesn't work, gather alternatives... */
1020	if (!ppmu->get_alternatives)
1021		return -1;
1022	for (i = 0; i < n_ev; ++i) {
1023		choice[i] = 0;
1024		n_alt[i] = ppmu->get_alternatives(event_id[i], cflags[i],
1025						  cpuhw->alternatives[i]);
1026		for (j = 1; j < n_alt[i]; ++j)
1027			ppmu->get_constraint(cpuhw->alternatives[i][j],
1028					     &cpuhw->amasks[i][j],
1029					     &cpuhw->avalues[i][j],
1030					     event[i]->attr.config1);
1031	}
1032
1033	/* enumerate all possibilities and see if any will work */
1034	i = 0;
1035	j = -1;
1036	value = mask = nv = 0;
1037	while (i < n_ev) {
1038		if (j >= 0) {
1039			/* we're backtracking, restore context */
1040			value = svalues[i];
1041			mask = smasks[i];
1042			j = choice[i];
1043		}
1044		/*
1045		 * See if any alternative k for event_id i,
1046		 * where k > j, will satisfy the constraints.
1047		 */
1048		while (++j < n_alt[i]) {
1049			nv = (value | cpuhw->avalues[i][j]) +
1050				(value & cpuhw->avalues[i][j] & addf);
1051			if ((((nv + tadd) ^ value) & mask) == 0 &&
1052			    (((nv + tadd) ^ cpuhw->avalues[i][j])
1053			     & cpuhw->amasks[i][j]) == 0)
1054				break;
1055		}
1056		if (j >= n_alt[i]) {
1057			/*
1058			 * No feasible alternative, backtrack
1059			 * to event_id i-1 and continue enumerating its
1060			 * alternatives from where we got up to.
1061			 */
1062			if (--i < 0)
1063				return -1;
1064		} else {
1065			/*
1066			 * Found a feasible alternative for event_id i,
1067			 * remember where we got up to with this event_id,
1068			 * go on to the next event_id, and start with
1069			 * the first alternative for it.
1070			 */
1071			choice[i] = j;
1072			svalues[i] = value;
1073			smasks[i] = mask;
1074			value = nv;
1075			mask |= cpuhw->amasks[i][j];
1076			++i;
1077			j = -1;
1078		}
1079	}
1080
1081	/* OK, we have a feasible combination, tell the caller the solution */
1082	for (i = 0; i < n_ev; ++i)
1083		event_id[i] = cpuhw->alternatives[i][choice[i]];
1084	return 0;
1085}
1086
1087/*
1088 * Check if newly-added events have consistent settings for
1089 * exclude_{user,kernel,hv} with each other and any previously
1090 * added events.
1091 */
1092static int check_excludes(struct perf_event **ctrs, unsigned int cflags[],
1093			  int n_prev, int n_new)
1094{
1095	int eu = 0, ek = 0, eh = 0;
1096	int i, n, first;
1097	struct perf_event *event;
1098
1099	/*
1100	 * If the PMU we're on supports per event exclude settings then we
1101	 * don't need to do any of this logic. NB. This assumes no PMU has both
1102	 * per event exclude and limited PMCs.
1103	 */
1104	if (ppmu->flags & PPMU_ARCH_207S)
1105		return 0;
1106
1107	n = n_prev + n_new;
1108	if (n <= 1)
1109		return 0;
1110
1111	first = 1;
1112	for (i = 0; i < n; ++i) {
1113		if (cflags[i] & PPMU_LIMITED_PMC_OK) {
1114			cflags[i] &= ~PPMU_LIMITED_PMC_REQD;
1115			continue;
1116		}
1117		event = ctrs[i];
1118		if (first) {
1119			eu = event->attr.exclude_user;
1120			ek = event->attr.exclude_kernel;
1121			eh = event->attr.exclude_hv;
1122			first = 0;
1123		} else if (event->attr.exclude_user != eu ||
1124			   event->attr.exclude_kernel != ek ||
1125			   event->attr.exclude_hv != eh) {
1126			return -EAGAIN;
1127		}
1128	}
1129
1130	if (eu || ek || eh)
1131		for (i = 0; i < n; ++i)
1132			if (cflags[i] & PPMU_LIMITED_PMC_OK)
1133				cflags[i] |= PPMU_LIMITED_PMC_REQD;
1134
1135	return 0;
1136}
1137
1138static u64 check_and_compute_delta(u64 prev, u64 val)
1139{
1140	u64 delta = (val - prev) & 0xfffffffful;
1141
1142	/*
1143	 * POWER7 can roll back counter values, if the new value is smaller
1144	 * than the previous value it will cause the delta and the counter to
1145	 * have bogus values unless we rolled a counter over.  If a counter is
1146	 * rolled back, it will be smaller, but within 256, which is the maximum
1147	 * number of events to rollback at once.  If we detect a rollback
1148	 * return 0.  This can lead to a small lack of precision in the
1149	 * counters.
1150	 */
1151	if (prev > val && (prev - val) < 256)
1152		delta = 0;
1153
1154	return delta;
1155}
1156
1157static void power_pmu_read(struct perf_event *event)
1158{
1159	s64 val, delta, prev;
1160
1161	if (event->hw.state & PERF_HES_STOPPED)
1162		return;
1163
1164	if (!event->hw.idx)
1165		return;
1166
1167	if (is_ebb_event(event)) {
1168		val = read_pmc(event->hw.idx);
1169		local64_set(&event->hw.prev_count, val);
1170		return;
1171	}
1172
1173	/*
1174	 * Performance monitor interrupts come even when interrupts
1175	 * are soft-disabled, as long as interrupts are hard-enabled.
1176	 * Therefore we treat them like NMIs.
1177	 */
1178	do {
1179		prev = local64_read(&event->hw.prev_count);
1180		barrier();
1181		val = read_pmc(event->hw.idx);
1182		delta = check_and_compute_delta(prev, val);
1183		if (!delta)
1184			return;
1185	} while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev);
1186
1187	local64_add(delta, &event->count);
1188
1189	/*
1190	 * A number of places program the PMC with (0x80000000 - period_left).
1191	 * We never want period_left to be less than 1 because we will program
1192	 * the PMC with a value >= 0x800000000 and an edge detected PMC will
1193	 * roll around to 0 before taking an exception. We have seen this
1194	 * on POWER8.
1195	 *
1196	 * To fix this, clamp the minimum value of period_left to 1.
1197	 */
1198	do {
1199		prev = local64_read(&event->hw.period_left);
1200		val = prev - delta;
1201		if (val < 1)
1202			val = 1;
1203	} while (local64_cmpxchg(&event->hw.period_left, prev, val) != prev);
1204}
1205
1206/*
1207 * On some machines, PMC5 and PMC6 can't be written, don't respect
1208 * the freeze conditions, and don't generate interrupts.  This tells
1209 * us if `event' is using such a PMC.
1210 */
1211static int is_limited_pmc(int pmcnum)
1212{
1213	return (ppmu->flags & PPMU_LIMITED_PMC5_6)
1214		&& (pmcnum == 5 || pmcnum == 6);
1215}
1216
1217static void freeze_limited_counters(struct cpu_hw_events *cpuhw,
1218				    unsigned long pmc5, unsigned long pmc6)
1219{
1220	struct perf_event *event;
1221	u64 val, prev, delta;
1222	int i;
1223
1224	for (i = 0; i < cpuhw->n_limited; ++i) {
1225		event = cpuhw->limited_counter[i];
1226		if (!event->hw.idx)
1227			continue;
1228		val = (event->hw.idx == 5) ? pmc5 : pmc6;
1229		prev = local64_read(&event->hw.prev_count);
1230		event->hw.idx = 0;
1231		delta = check_and_compute_delta(prev, val);
1232		if (delta)
1233			local64_add(delta, &event->count);
1234	}
1235}
1236
1237static void thaw_limited_counters(struct cpu_hw_events *cpuhw,
1238				  unsigned long pmc5, unsigned long pmc6)
1239{
1240	struct perf_event *event;
1241	u64 val, prev;
1242	int i;
1243
1244	for (i = 0; i < cpuhw->n_limited; ++i) {
1245		event = cpuhw->limited_counter[i];
1246		event->hw.idx = cpuhw->limited_hwidx[i];
1247		val = (event->hw.idx == 5) ? pmc5 : pmc6;
1248		prev = local64_read(&event->hw.prev_count);
1249		if (check_and_compute_delta(prev, val))
1250			local64_set(&event->hw.prev_count, val);
1251		perf_event_update_userpage(event);
1252	}
1253}
1254
1255/*
1256 * Since limited events don't respect the freeze conditions, we
1257 * have to read them immediately after freezing or unfreezing the
1258 * other events.  We try to keep the values from the limited
1259 * events as consistent as possible by keeping the delay (in
1260 * cycles and instructions) between freezing/unfreezing and reading
1261 * the limited events as small and consistent as possible.
1262 * Therefore, if any limited events are in use, we read them
1263 * both, and always in the same order, to minimize variability,
1264 * and do it inside the same asm that writes MMCR0.
1265 */
1266static void write_mmcr0(struct cpu_hw_events *cpuhw, unsigned long mmcr0)
1267{
1268	unsigned long pmc5, pmc6;
1269
1270	if (!cpuhw->n_limited) {
1271		mtspr(SPRN_MMCR0, mmcr0);
1272		return;
1273	}
1274
1275	/*
1276	 * Write MMCR0, then read PMC5 and PMC6 immediately.
1277	 * To ensure we don't get a performance monitor interrupt
1278	 * between writing MMCR0 and freezing/thawing the limited
1279	 * events, we first write MMCR0 with the event overflow
1280	 * interrupt enable bits turned off.
1281	 */
1282	asm volatile("mtspr %3,%2; mfspr %0,%4; mfspr %1,%5"
1283		     : "=&r" (pmc5), "=&r" (pmc6)
1284		     : "r" (mmcr0 & ~(MMCR0_PMC1CE | MMCR0_PMCjCE)),
1285		       "i" (SPRN_MMCR0),
1286		       "i" (SPRN_PMC5), "i" (SPRN_PMC6));
1287
1288	if (mmcr0 & MMCR0_FC)
1289		freeze_limited_counters(cpuhw, pmc5, pmc6);
1290	else
1291		thaw_limited_counters(cpuhw, pmc5, pmc6);
1292
1293	/*
1294	 * Write the full MMCR0 including the event overflow interrupt
1295	 * enable bits, if necessary.
1296	 */
1297	if (mmcr0 & (MMCR0_PMC1CE | MMCR0_PMCjCE))
1298		mtspr(SPRN_MMCR0, mmcr0);
1299}
1300
1301/*
1302 * Disable all events to prevent PMU interrupts and to allow
1303 * events to be added or removed.
1304 */
1305static void power_pmu_disable(struct pmu *pmu)
1306{
1307	struct cpu_hw_events *cpuhw;
1308	unsigned long flags, mmcr0, val, mmcra;
1309
1310	if (!ppmu)
1311		return;
1312	local_irq_save(flags);
1313	cpuhw = this_cpu_ptr(&cpu_hw_events);
1314
1315	if (!cpuhw->disabled) {
1316		/*
1317		 * Check if we ever enabled the PMU on this cpu.
1318		 */
1319		if (!cpuhw->pmcs_enabled) {
1320			ppc_enable_pmcs();
1321			cpuhw->pmcs_enabled = 1;
1322		}
1323
1324		/*
1325		 * Set the 'freeze counters' bit, clear EBE/BHRBA/PMCC/PMAO/FC56
1326		 * Also clear PMXE to disable PMI's getting triggered in some
1327		 * corner cases during PMU disable.
1328		 */
1329		val  = mmcr0 = mfspr(SPRN_MMCR0);
1330		val |= MMCR0_FC;
1331		val &= ~(MMCR0_EBE | MMCR0_BHRBA | MMCR0_PMCC | MMCR0_PMAO |
1332			 MMCR0_PMXE | MMCR0_FC56);
1333		/* Set mmcr0 PMCCEXT for p10 */
1334		if (ppmu->flags & PPMU_ARCH_31)
1335			val |= MMCR0_PMCCEXT;
1336
1337		/*
1338		 * The barrier is to make sure the mtspr has been
1339		 * executed and the PMU has frozen the events etc.
1340		 * before we return.
1341		 */
1342		write_mmcr0(cpuhw, val);
1343		mb();
1344		isync();
1345
1346		/*
1347		 * Some corner cases could clear the PMU counter overflow
1348		 * while a masked PMI is pending. One such case is when
1349		 * a PMI happens during interrupt replay and perf counter
1350		 * values are cleared by PMU callbacks before replay.
1351		 *
1352		 * Disable the interrupt by clearing the paca bit for PMI
1353		 * since we are disabling the PMU now. Otherwise provide a
1354		 * warning if there is PMI pending, but no counter is found
1355		 * overflown.
1356		 *
1357		 * Since power_pmu_disable runs under local_irq_save, it
1358		 * could happen that code hits a PMC overflow without PMI
1359		 * pending in paca. Hence only clear PMI pending if it was
1360		 * set.
1361		 *
1362		 * If a PMI is pending, then MSR[EE] must be disabled (because
1363		 * the masked PMI handler disabling EE). So it is safe to
1364		 * call clear_pmi_irq_pending().
1365		 */
1366		if (pmi_irq_pending())
1367			clear_pmi_irq_pending();
1368
1369		val = mmcra = cpuhw->mmcr.mmcra;
1370
1371		/*
1372		 * Disable instruction sampling if it was enabled
1373		 */
1374		val &= ~MMCRA_SAMPLE_ENABLE;
1375
1376		/* Disable BHRB via mmcra (BHRBRD) for p10 */
1377		if (ppmu->flags & PPMU_ARCH_31)
1378			val |= MMCRA_BHRB_DISABLE;
1379
1380		/*
1381		 * Write SPRN_MMCRA if mmcra has either disabled
1382		 * instruction sampling or BHRB.
1383		 */
1384		if (val != mmcra) {
1385			mtspr(SPRN_MMCRA, val);
1386			mb();
1387			isync();
1388		}
1389
1390		cpuhw->disabled = 1;
1391		cpuhw->n_added = 0;
1392
1393		ebb_switch_out(mmcr0);
1394
1395#ifdef CONFIG_PPC64
1396		/*
1397		 * These are readable by userspace, may contain kernel
1398		 * addresses and are not switched by context switch, so clear
1399		 * them now to avoid leaking anything to userspace in general
1400		 * including to another process.
1401		 */
1402		if (ppmu->flags & PPMU_ARCH_207S) {
1403			mtspr(SPRN_SDAR, 0);
1404			mtspr(SPRN_SIAR, 0);
1405		}
1406#endif
1407	}
1408
1409	local_irq_restore(flags);
1410}
1411
1412/*
1413 * Re-enable all events if disable == 0.
1414 * If we were previously disabled and events were added, then
1415 * put the new config on the PMU.
1416 */
1417static void power_pmu_enable(struct pmu *pmu)
1418{
1419	struct perf_event *event;
1420	struct cpu_hw_events *cpuhw;
1421	unsigned long flags;
1422	long i;
1423	unsigned long val, mmcr0;
1424	s64 left;
1425	unsigned int hwc_index[MAX_HWEVENTS];
1426	int n_lim;
1427	int idx;
1428	bool ebb;
1429
1430	if (!ppmu)
1431		return;
1432	local_irq_save(flags);
1433
1434	cpuhw = this_cpu_ptr(&cpu_hw_events);
1435	if (!cpuhw->disabled)
1436		goto out;
1437
1438	if (cpuhw->n_events == 0) {
1439		ppc_set_pmu_inuse(0);
1440		goto out;
1441	}
1442
1443	cpuhw->disabled = 0;
1444
1445	/*
1446	 * EBB requires an exclusive group and all events must have the EBB
1447	 * flag set, or not set, so we can just check a single event. Also we
1448	 * know we have at least one event.
1449	 */
1450	ebb = is_ebb_event(cpuhw->event[0]);
1451
1452	/*
1453	 * If we didn't change anything, or only removed events,
1454	 * no need to recalculate MMCR* settings and reset the PMCs.
1455	 * Just reenable the PMU with the current MMCR* settings
1456	 * (possibly updated for removal of events).
1457	 */
1458	if (!cpuhw->n_added) {
1459		/*
1460		 * If there is any active event with an overflown PMC
1461		 * value, set back PACA_IRQ_PMI which would have been
1462		 * cleared in power_pmu_disable().
1463		 */
1464		hard_irq_disable();
1465		if (any_pmc_overflown(cpuhw))
1466			set_pmi_irq_pending();
1467
1468		mtspr(SPRN_MMCRA, cpuhw->mmcr.mmcra & ~MMCRA_SAMPLE_ENABLE);
1469		mtspr(SPRN_MMCR1, cpuhw->mmcr.mmcr1);
1470		if (ppmu->flags & PPMU_ARCH_31)
1471			mtspr(SPRN_MMCR3, cpuhw->mmcr.mmcr3);
1472		goto out_enable;
1473	}
1474
1475	/*
1476	 * Clear all MMCR settings and recompute them for the new set of events.
1477	 */
1478	memset(&cpuhw->mmcr, 0, sizeof(cpuhw->mmcr));
1479
1480	if (ppmu->compute_mmcr(cpuhw->events, cpuhw->n_events, hwc_index,
1481			       &cpuhw->mmcr, cpuhw->event, ppmu->flags)) {
1482		/* shouldn't ever get here */
1483		printk(KERN_ERR "oops compute_mmcr failed\n");
1484		goto out;
1485	}
1486
1487	if (!(ppmu->flags & PPMU_ARCH_207S)) {
1488		/*
1489		 * Add in MMCR0 freeze bits corresponding to the attr.exclude_*
1490		 * bits for the first event. We have already checked that all
1491		 * events have the same value for these bits as the first event.
1492		 */
1493		event = cpuhw->event[0];
1494		if (event->attr.exclude_user)
1495			cpuhw->mmcr.mmcr0 |= MMCR0_FCP;
1496		if (event->attr.exclude_kernel)
1497			cpuhw->mmcr.mmcr0 |= freeze_events_kernel;
1498		if (event->attr.exclude_hv)
1499			cpuhw->mmcr.mmcr0 |= MMCR0_FCHV;
1500	}
1501
1502	/*
1503	 * Write the new configuration to MMCR* with the freeze
1504	 * bit set and set the hardware events to their initial values.
1505	 * Then unfreeze the events.
1506	 */
1507	ppc_set_pmu_inuse(1);
1508	mtspr(SPRN_MMCRA, cpuhw->mmcr.mmcra & ~MMCRA_SAMPLE_ENABLE);
1509	mtspr(SPRN_MMCR1, cpuhw->mmcr.mmcr1);
1510	mtspr(SPRN_MMCR0, (cpuhw->mmcr.mmcr0 & ~(MMCR0_PMC1CE | MMCR0_PMCjCE))
1511				| MMCR0_FC);
1512	if (ppmu->flags & PPMU_ARCH_207S)
1513		mtspr(SPRN_MMCR2, cpuhw->mmcr.mmcr2);
1514
1515	if (ppmu->flags & PPMU_ARCH_31)
1516		mtspr(SPRN_MMCR3, cpuhw->mmcr.mmcr3);
1517
1518	/*
1519	 * Read off any pre-existing events that need to move
1520	 * to another PMC.
1521	 */
1522	for (i = 0; i < cpuhw->n_events; ++i) {
1523		event = cpuhw->event[i];
1524		if (event->hw.idx && event->hw.idx != hwc_index[i] + 1) {
1525			power_pmu_read(event);
1526			write_pmc(event->hw.idx, 0);
1527			event->hw.idx = 0;
1528		}
1529	}
1530
1531	/*
1532	 * Initialize the PMCs for all the new and moved events.
1533	 */
1534	cpuhw->n_limited = n_lim = 0;
1535	for (i = 0; i < cpuhw->n_events; ++i) {
1536		event = cpuhw->event[i];
1537		if (event->hw.idx)
1538			continue;
1539		idx = hwc_index[i] + 1;
1540		if (is_limited_pmc(idx)) {
1541			cpuhw->limited_counter[n_lim] = event;
1542			cpuhw->limited_hwidx[n_lim] = idx;
1543			++n_lim;
1544			continue;
1545		}
1546
1547		if (ebb)
1548			val = local64_read(&event->hw.prev_count);
1549		else {
1550			val = 0;
1551			if (event->hw.sample_period) {
1552				left = local64_read(&event->hw.period_left);
1553				if (left < 0x80000000L)
1554					val = 0x80000000L - left;
1555			}
1556			local64_set(&event->hw.prev_count, val);
1557		}
1558
1559		event->hw.idx = idx;
1560		if (event->hw.state & PERF_HES_STOPPED)
1561			val = 0;
1562		write_pmc(idx, val);
1563
1564		perf_event_update_userpage(event);
1565	}
1566	cpuhw->n_limited = n_lim;
1567	cpuhw->mmcr.mmcr0 |= MMCR0_PMXE | MMCR0_FCECE;
1568
1569 out_enable:
1570	pmao_restore_workaround(ebb);
1571
1572	mmcr0 = ebb_switch_in(ebb, cpuhw);
1573
1574	mb();
1575	if (cpuhw->bhrb_users)
1576		ppmu->config_bhrb(cpuhw->bhrb_filter);
1577
1578	write_mmcr0(cpuhw, mmcr0);
1579
1580	/*
1581	 * Enable instruction sampling if necessary
1582	 */
1583	if (cpuhw->mmcr.mmcra & MMCRA_SAMPLE_ENABLE) {
1584		mb();
1585		mtspr(SPRN_MMCRA, cpuhw->mmcr.mmcra);
1586	}
1587
1588 out:
1589
1590	local_irq_restore(flags);
1591}
1592
1593static int collect_events(struct perf_event *group, int max_count,
1594			  struct perf_event *ctrs[], u64 *events,
1595			  unsigned int *flags)
1596{
1597	int n = 0;
1598	struct perf_event *event;
1599
1600	if (group->pmu->task_ctx_nr == perf_hw_context) {
1601		if (n >= max_count)
1602			return -1;
1603		ctrs[n] = group;
1604		flags[n] = group->hw.event_base;
1605		events[n++] = group->hw.config;
1606	}
1607	for_each_sibling_event(event, group) {
1608		if (event->pmu->task_ctx_nr == perf_hw_context &&
1609		    event->state != PERF_EVENT_STATE_OFF) {
1610			if (n >= max_count)
1611				return -1;
1612			ctrs[n] = event;
1613			flags[n] = event->hw.event_base;
1614			events[n++] = event->hw.config;
1615		}
1616	}
1617	return n;
1618}
1619
1620/*
1621 * Add an event to the PMU.
1622 * If all events are not already frozen, then we disable and
1623 * re-enable the PMU in order to get hw_perf_enable to do the
1624 * actual work of reconfiguring the PMU.
1625 */
1626static int power_pmu_add(struct perf_event *event, int ef_flags)
1627{
1628	struct cpu_hw_events *cpuhw;
1629	unsigned long flags;
1630	int n0;
1631	int ret = -EAGAIN;
1632
1633	local_irq_save(flags);
1634	perf_pmu_disable(event->pmu);
1635
1636	/*
1637	 * Add the event to the list (if there is room)
1638	 * and check whether the total set is still feasible.
1639	 */
1640	cpuhw = this_cpu_ptr(&cpu_hw_events);
1641	n0 = cpuhw->n_events;
1642	if (n0 >= ppmu->n_counter)
1643		goto out;
1644	cpuhw->event[n0] = event;
1645	cpuhw->events[n0] = event->hw.config;
1646	cpuhw->flags[n0] = event->hw.event_base;
1647
1648	/*
1649	 * This event may have been disabled/stopped in record_and_restart()
1650	 * because we exceeded the ->event_limit. If re-starting the event,
1651	 * clear the ->hw.state (STOPPED and UPTODATE flags), so the user
1652	 * notification is re-enabled.
1653	 */
1654	if (!(ef_flags & PERF_EF_START))
1655		event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
1656	else
1657		event->hw.state = 0;
1658
1659	/*
1660	 * If group events scheduling transaction was started,
1661	 * skip the schedulability test here, it will be performed
1662	 * at commit time(->commit_txn) as a whole
1663	 */
1664	if (cpuhw->txn_flags & PERF_PMU_TXN_ADD)
1665		goto nocheck;
1666
1667	if (check_excludes(cpuhw->event, cpuhw->flags, n0, 1))
1668		goto out;
1669	if (power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n0 + 1, cpuhw->event))
1670		goto out;
1671	event->hw.config = cpuhw->events[n0];
1672
1673nocheck:
1674	ebb_event_add(event);
1675
1676	++cpuhw->n_events;
1677	++cpuhw->n_added;
1678
1679	ret = 0;
1680 out:
1681	if (has_branch_stack(event)) {
1682		u64 bhrb_filter = -1;
1683
1684		if (ppmu->bhrb_filter_map)
1685			bhrb_filter = ppmu->bhrb_filter_map(
1686				event->attr.branch_sample_type);
1687
1688		if (bhrb_filter != -1) {
1689			cpuhw->bhrb_filter = bhrb_filter;
1690			power_pmu_bhrb_enable(event);
1691		}
1692	}
1693
1694	perf_pmu_enable(event->pmu);
1695	local_irq_restore(flags);
1696	return ret;
1697}
1698
1699/*
1700 * Remove an event from the PMU.
1701 */
1702static void power_pmu_del(struct perf_event *event, int ef_flags)
1703{
1704	struct cpu_hw_events *cpuhw;
1705	long i;
1706	unsigned long flags;
1707
1708	local_irq_save(flags);
1709	perf_pmu_disable(event->pmu);
1710
1711	power_pmu_read(event);
1712
1713	cpuhw = this_cpu_ptr(&cpu_hw_events);
1714	for (i = 0; i < cpuhw->n_events; ++i) {
1715		if (event == cpuhw->event[i]) {
1716			while (++i < cpuhw->n_events) {
1717				cpuhw->event[i-1] = cpuhw->event[i];
1718				cpuhw->events[i-1] = cpuhw->events[i];
1719				cpuhw->flags[i-1] = cpuhw->flags[i];
1720			}
1721			--cpuhw->n_events;
1722			ppmu->disable_pmc(event->hw.idx - 1, &cpuhw->mmcr);
1723			if (event->hw.idx) {
1724				write_pmc(event->hw.idx, 0);
1725				event->hw.idx = 0;
1726			}
1727			perf_event_update_userpage(event);
1728			break;
1729		}
1730	}
1731	for (i = 0; i < cpuhw->n_limited; ++i)
1732		if (event == cpuhw->limited_counter[i])
1733			break;
1734	if (i < cpuhw->n_limited) {
1735		while (++i < cpuhw->n_limited) {
1736			cpuhw->limited_counter[i-1] = cpuhw->limited_counter[i];
1737			cpuhw->limited_hwidx[i-1] = cpuhw->limited_hwidx[i];
1738		}
1739		--cpuhw->n_limited;
1740	}
1741	if (cpuhw->n_events == 0) {
1742		/* disable exceptions if no events are running */
1743		cpuhw->mmcr.mmcr0 &= ~(MMCR0_PMXE | MMCR0_FCECE);
1744	}
1745
1746	if (has_branch_stack(event))
1747		power_pmu_bhrb_disable(event);
1748
1749	perf_pmu_enable(event->pmu);
1750	local_irq_restore(flags);
1751}
1752
1753/*
1754 * POWER-PMU does not support disabling individual counters, hence
1755 * program their cycle counter to their max value and ignore the interrupts.
1756 */
1757
1758static void power_pmu_start(struct perf_event *event, int ef_flags)
1759{
1760	unsigned long flags;
1761	s64 left;
1762	unsigned long val;
1763
1764	if (!event->hw.idx || !event->hw.sample_period)
1765		return;
1766
1767	if (!(event->hw.state & PERF_HES_STOPPED))
1768		return;
1769
1770	if (ef_flags & PERF_EF_RELOAD)
1771		WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
1772
1773	local_irq_save(flags);
1774	perf_pmu_disable(event->pmu);
1775
1776	event->hw.state = 0;
1777	left = local64_read(&event->hw.period_left);
1778
1779	val = 0;
1780	if (left < 0x80000000L)
1781		val = 0x80000000L - left;
1782
1783	write_pmc(event->hw.idx, val);
1784
1785	perf_event_update_userpage(event);
1786	perf_pmu_enable(event->pmu);
1787	local_irq_restore(flags);
1788}
1789
1790static void power_pmu_stop(struct perf_event *event, int ef_flags)
1791{
1792	unsigned long flags;
1793
1794	if (!event->hw.idx || !event->hw.sample_period)
1795		return;
1796
1797	if (event->hw.state & PERF_HES_STOPPED)
1798		return;
1799
1800	local_irq_save(flags);
1801	perf_pmu_disable(event->pmu);
1802
1803	power_pmu_read(event);
1804	event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
1805	write_pmc(event->hw.idx, 0);
1806
1807	perf_event_update_userpage(event);
1808	perf_pmu_enable(event->pmu);
1809	local_irq_restore(flags);
1810}
1811
1812/*
1813 * Start group events scheduling transaction
1814 * Set the flag to make pmu::enable() not perform the
1815 * schedulability test, it will be performed at commit time
1816 *
1817 * We only support PERF_PMU_TXN_ADD transactions. Save the
1818 * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD
1819 * transactions.
1820 */
1821static void power_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags)
1822{
1823	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
1824
1825	WARN_ON_ONCE(cpuhw->txn_flags);		/* txn already in flight */
1826
1827	cpuhw->txn_flags = txn_flags;
1828	if (txn_flags & ~PERF_PMU_TXN_ADD)
1829		return;
1830
1831	perf_pmu_disable(pmu);
1832	cpuhw->n_txn_start = cpuhw->n_events;
1833}
1834
1835/*
1836 * Stop group events scheduling transaction
1837 * Clear the flag and pmu::enable() will perform the
1838 * schedulability test.
1839 */
1840static void power_pmu_cancel_txn(struct pmu *pmu)
1841{
1842	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
1843	unsigned int txn_flags;
1844
1845	WARN_ON_ONCE(!cpuhw->txn_flags);	/* no txn in flight */
1846
1847	txn_flags = cpuhw->txn_flags;
1848	cpuhw->txn_flags = 0;
1849	if (txn_flags & ~PERF_PMU_TXN_ADD)
1850		return;
1851
1852	perf_pmu_enable(pmu);
1853}
1854
1855/*
1856 * Commit group events scheduling transaction
1857 * Perform the group schedulability test as a whole
1858 * Return 0 if success
1859 */
1860static int power_pmu_commit_txn(struct pmu *pmu)
1861{
1862	struct cpu_hw_events *cpuhw;
1863	long i, n;
1864
1865	if (!ppmu)
1866		return -EAGAIN;
1867
1868	cpuhw = this_cpu_ptr(&cpu_hw_events);
1869	WARN_ON_ONCE(!cpuhw->txn_flags);	/* no txn in flight */
1870
1871	if (cpuhw->txn_flags & ~PERF_PMU_TXN_ADD) {
1872		cpuhw->txn_flags = 0;
1873		return 0;
1874	}
1875
1876	n = cpuhw->n_events;
1877	if (check_excludes(cpuhw->event, cpuhw->flags, 0, n))
1878		return -EAGAIN;
1879	i = power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n, cpuhw->event);
1880	if (i < 0)
1881		return -EAGAIN;
1882
1883	for (i = cpuhw->n_txn_start; i < n; ++i)
1884		cpuhw->event[i]->hw.config = cpuhw->events[i];
1885
1886	cpuhw->txn_flags = 0;
1887	perf_pmu_enable(pmu);
1888	return 0;
1889}
1890
1891/*
1892 * Return 1 if we might be able to put event on a limited PMC,
1893 * or 0 if not.
1894 * An event can only go on a limited PMC if it counts something
1895 * that a limited PMC can count, doesn't require interrupts, and
1896 * doesn't exclude any processor mode.
1897 */
1898static int can_go_on_limited_pmc(struct perf_event *event, u64 ev,
1899				 unsigned int flags)
1900{
1901	int n;
1902	u64 alt[MAX_EVENT_ALTERNATIVES];
1903
1904	if (event->attr.exclude_user
1905	    || event->attr.exclude_kernel
1906	    || event->attr.exclude_hv
1907	    || event->attr.sample_period)
1908		return 0;
1909
1910	if (ppmu->limited_pmc_event(ev))
1911		return 1;
1912
1913	/*
1914	 * The requested event_id isn't on a limited PMC already;
1915	 * see if any alternative code goes on a limited PMC.
1916	 */
1917	if (!ppmu->get_alternatives)
1918		return 0;
1919
1920	flags |= PPMU_LIMITED_PMC_OK | PPMU_LIMITED_PMC_REQD;
1921	n = ppmu->get_alternatives(ev, flags, alt);
1922
1923	return n > 0;
1924}
1925
1926/*
1927 * Find an alternative event_id that goes on a normal PMC, if possible,
1928 * and return the event_id code, or 0 if there is no such alternative.
1929 * (Note: event_id code 0 is "don't count" on all machines.)
1930 */
1931static u64 normal_pmc_alternative(u64 ev, unsigned long flags)
1932{
1933	u64 alt[MAX_EVENT_ALTERNATIVES];
1934	int n;
1935
1936	flags &= ~(PPMU_LIMITED_PMC_OK | PPMU_LIMITED_PMC_REQD);
1937	n = ppmu->get_alternatives(ev, flags, alt);
1938	if (!n)
1939		return 0;
1940	return alt[0];
1941}
1942
1943/* Number of perf_events counting hardware events */
1944static atomic_t num_events;
1945/* Used to avoid races in calling reserve/release_pmc_hardware */
1946static DEFINE_MUTEX(pmc_reserve_mutex);
1947
1948/*
1949 * Release the PMU if this is the last perf_event.
1950 */
1951static void hw_perf_event_destroy(struct perf_event *event)
1952{
1953	if (!atomic_add_unless(&num_events, -1, 1)) {
1954		mutex_lock(&pmc_reserve_mutex);
1955		if (atomic_dec_return(&num_events) == 0)
1956			release_pmc_hardware();
1957		mutex_unlock(&pmc_reserve_mutex);
1958	}
1959}
1960
1961/*
1962 * Translate a generic cache event_id config to a raw event_id code.
1963 */
1964static int hw_perf_cache_event(u64 config, u64 *eventp)
1965{
1966	unsigned long type, op, result;
1967	u64 ev;
1968
1969	if (!ppmu->cache_events)
1970		return -EINVAL;
1971
1972	/* unpack config */
1973	type = config & 0xff;
1974	op = (config >> 8) & 0xff;
1975	result = (config >> 16) & 0xff;
1976
1977	if (type >= PERF_COUNT_HW_CACHE_MAX ||
1978	    op >= PERF_COUNT_HW_CACHE_OP_MAX ||
1979	    result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
1980		return -EINVAL;
1981
1982	ev = (*ppmu->cache_events)[type][op][result];
1983	if (ev == 0)
1984		return -EOPNOTSUPP;
1985	if (ev == -1)
1986		return -EINVAL;
1987	*eventp = ev;
1988	return 0;
1989}
1990
1991static bool is_event_blacklisted(u64 ev)
1992{
1993	int i;
1994
1995	for (i=0; i < ppmu->n_blacklist_ev; i++) {
1996		if (ppmu->blacklist_ev[i] == ev)
1997			return true;
1998	}
1999
2000	return false;
2001}
2002
2003static int power_pmu_event_init(struct perf_event *event)
2004{
2005	u64 ev;
2006	unsigned long flags, irq_flags;
2007	struct perf_event *ctrs[MAX_HWEVENTS];
2008	u64 events[MAX_HWEVENTS];
2009	unsigned int cflags[MAX_HWEVENTS];
2010	int n;
2011	int err;
2012	struct cpu_hw_events *cpuhw;
2013
2014	if (!ppmu)
2015		return -ENOENT;
2016
2017	if (has_branch_stack(event)) {
2018	        /* PMU has BHRB enabled */
2019		if (!(ppmu->flags & PPMU_ARCH_207S))
2020			return -EOPNOTSUPP;
2021	}
2022
2023	switch (event->attr.type) {
2024	case PERF_TYPE_HARDWARE:
2025		ev = event->attr.config;
2026		if (ev >= ppmu->n_generic || ppmu->generic_events[ev] == 0)
2027			return -EOPNOTSUPP;
2028
2029		if (ppmu->blacklist_ev && is_event_blacklisted(ev))
2030			return -EINVAL;
2031		ev = ppmu->generic_events[ev];
2032		break;
2033	case PERF_TYPE_HW_CACHE:
2034		err = hw_perf_cache_event(event->attr.config, &ev);
2035		if (err)
2036			return err;
2037
2038		if (ppmu->blacklist_ev && is_event_blacklisted(ev))
2039			return -EINVAL;
2040		break;
2041	case PERF_TYPE_RAW:
2042		ev = event->attr.config;
2043
2044		if (ppmu->blacklist_ev && is_event_blacklisted(ev))
2045			return -EINVAL;
2046		break;
2047	default:
2048		return -ENOENT;
2049	}
2050
2051	/*
2052	 * PMU config registers have fields that are
2053	 * reserved and some specific values for bit fields are reserved.
2054	 * For ex., MMCRA[61:62] is Random Sampling Mode (SM)
2055	 * and value of 0b11 to this field is reserved.
2056	 * Check for invalid values in attr.config.
2057	 */
2058	if (ppmu->check_attr_config &&
2059	    ppmu->check_attr_config(event))
2060		return -EINVAL;
2061
2062	event->hw.config_base = ev;
2063	event->hw.idx = 0;
2064
2065	/*
2066	 * If we are not running on a hypervisor, force the
2067	 * exclude_hv bit to 0 so that we don't care what
2068	 * the user set it to.
2069	 */
2070	if (!firmware_has_feature(FW_FEATURE_LPAR))
2071		event->attr.exclude_hv = 0;
2072
2073	/*
2074	 * If this is a per-task event, then we can use
2075	 * PM_RUN_* events interchangeably with their non RUN_*
2076	 * equivalents, e.g. PM_RUN_CYC instead of PM_CYC.
2077	 * XXX we should check if the task is an idle task.
2078	 */
2079	flags = 0;
2080	if (event->attach_state & PERF_ATTACH_TASK)
2081		flags |= PPMU_ONLY_COUNT_RUN;
2082
2083	/*
2084	 * If this machine has limited events, check whether this
2085	 * event_id could go on a limited event.
2086	 */
2087	if (ppmu->flags & PPMU_LIMITED_PMC5_6) {
2088		if (can_go_on_limited_pmc(event, ev, flags)) {
2089			flags |= PPMU_LIMITED_PMC_OK;
2090		} else if (ppmu->limited_pmc_event(ev)) {
2091			/*
2092			 * The requested event_id is on a limited PMC,
2093			 * but we can't use a limited PMC; see if any
2094			 * alternative goes on a normal PMC.
2095			 */
2096			ev = normal_pmc_alternative(ev, flags);
2097			if (!ev)
2098				return -EINVAL;
2099		}
2100	}
2101
2102	/* Extra checks for EBB */
2103	err = ebb_event_check(event);
2104	if (err)
2105		return err;
2106
2107	/*
2108	 * If this is in a group, check if it can go on with all the
2109	 * other hardware events in the group.  We assume the event
2110	 * hasn't been linked into its leader's sibling list at this point.
2111	 */
2112	n = 0;
2113	if (event->group_leader != event) {
2114		n = collect_events(event->group_leader, ppmu->n_counter - 1,
2115				   ctrs, events, cflags);
2116		if (n < 0)
2117			return -EINVAL;
2118	}
2119	events[n] = ev;
2120	ctrs[n] = event;
2121	cflags[n] = flags;
2122	if (check_excludes(ctrs, cflags, n, 1))
2123		return -EINVAL;
2124
2125	local_irq_save(irq_flags);
2126	cpuhw = this_cpu_ptr(&cpu_hw_events);
2127
2128	err = power_check_constraints(cpuhw, events, cflags, n + 1, ctrs);
2129
2130	if (has_branch_stack(event)) {
2131		u64 bhrb_filter = -1;
2132
2133		/*
2134		 * Currently no PMU supports having multiple branch filters
2135		 * at the same time. Branch filters are set via MMCRA IFM[32:33]
2136		 * bits for Power8 and above. Return EOPNOTSUPP when multiple
2137		 * branch filters are requested in the event attr.
2138		 *
2139		 * When opening event via perf_event_open(), branch_sample_type
2140		 * gets adjusted in perf_copy_attr(). Kernel will automatically
2141		 * adjust the branch_sample_type based on the event modifier
2142		 * settings to include PERF_SAMPLE_BRANCH_PLM_ALL. Hence drop
2143		 * the check for PERF_SAMPLE_BRANCH_PLM_ALL.
2144		 */
2145		if (hweight64(event->attr.branch_sample_type & ~PERF_SAMPLE_BRANCH_PLM_ALL) > 1) {
2146			local_irq_restore(irq_flags);
2147			return -EOPNOTSUPP;
2148		}
2149
2150		if (ppmu->bhrb_filter_map)
2151			bhrb_filter = ppmu->bhrb_filter_map(
2152					event->attr.branch_sample_type);
2153
2154		if (bhrb_filter == -1) {
2155			local_irq_restore(irq_flags);
2156			return -EOPNOTSUPP;
2157		}
2158		cpuhw->bhrb_filter = bhrb_filter;
2159	}
2160
2161	local_irq_restore(irq_flags);
2162	if (err)
2163		return -EINVAL;
2164
2165	event->hw.config = events[n];
2166	event->hw.event_base = cflags[n];
2167	event->hw.last_period = event->hw.sample_period;
2168	local64_set(&event->hw.period_left, event->hw.last_period);
2169
2170	/*
2171	 * For EBB events we just context switch the PMC value, we don't do any
2172	 * of the sample_period logic. We use hw.prev_count for this.
2173	 */
2174	if (is_ebb_event(event))
2175		local64_set(&event->hw.prev_count, 0);
2176
2177	/*
2178	 * See if we need to reserve the PMU.
2179	 * If no events are currently in use, then we have to take a
2180	 * mutex to ensure that we don't race with another task doing
2181	 * reserve_pmc_hardware or release_pmc_hardware.
2182	 */
2183	err = 0;
2184	if (!atomic_inc_not_zero(&num_events)) {
2185		mutex_lock(&pmc_reserve_mutex);
2186		if (atomic_read(&num_events) == 0 &&
2187		    reserve_pmc_hardware(perf_event_interrupt))
2188			err = -EBUSY;
2189		else
2190			atomic_inc(&num_events);
2191		mutex_unlock(&pmc_reserve_mutex);
2192	}
2193	event->destroy = hw_perf_event_destroy;
2194
2195	return err;
2196}
2197
2198static int power_pmu_event_idx(struct perf_event *event)
2199{
2200	return event->hw.idx;
2201}
2202
2203ssize_t power_events_sysfs_show(struct device *dev,
2204				struct device_attribute *attr, char *page)
2205{
2206	struct perf_pmu_events_attr *pmu_attr;
2207
2208	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
2209
2210	return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
2211}
2212
2213static struct pmu power_pmu = {
2214	.pmu_enable	= power_pmu_enable,
2215	.pmu_disable	= power_pmu_disable,
2216	.event_init	= power_pmu_event_init,
2217	.add		= power_pmu_add,
2218	.del		= power_pmu_del,
2219	.start		= power_pmu_start,
2220	.stop		= power_pmu_stop,
2221	.read		= power_pmu_read,
2222	.start_txn	= power_pmu_start_txn,
2223	.cancel_txn	= power_pmu_cancel_txn,
2224	.commit_txn	= power_pmu_commit_txn,
2225	.event_idx	= power_pmu_event_idx,
2226	.sched_task	= power_pmu_sched_task,
2227};
2228
2229#define PERF_SAMPLE_ADDR_TYPE  (PERF_SAMPLE_ADDR |		\
2230				PERF_SAMPLE_PHYS_ADDR |		\
2231				PERF_SAMPLE_DATA_PAGE_SIZE)
2232/*
2233 * A counter has overflowed; update its count and record
2234 * things if requested.  Note that interrupts are hard-disabled
2235 * here so there is no possibility of being interrupted.
2236 */
2237static void record_and_restart(struct perf_event *event, unsigned long val,
2238			       struct pt_regs *regs)
2239{
2240	u64 period = event->hw.sample_period;
2241	s64 prev, delta, left;
2242	int record = 0;
2243
2244	if (event->hw.state & PERF_HES_STOPPED) {
2245		write_pmc(event->hw.idx, 0);
2246		return;
2247	}
2248
2249	/* we don't have to worry about interrupts here */
2250	prev = local64_read(&event->hw.prev_count);
2251	delta = check_and_compute_delta(prev, val);
2252	local64_add(delta, &event->count);
2253
2254	/*
2255	 * See if the total period for this event has expired,
2256	 * and update for the next period.
2257	 */
2258	val = 0;
2259	left = local64_read(&event->hw.period_left) - delta;
2260	if (delta == 0)
2261		left++;
2262	if (period) {
2263		if (left <= 0) {
2264			left += period;
2265			if (left <= 0)
2266				left = period;
2267
2268			/*
2269			 * If address is not requested in the sample via
2270			 * PERF_SAMPLE_IP, just record that sample irrespective
2271			 * of SIAR valid check.
2272			 */
2273			if (event->attr.sample_type & PERF_SAMPLE_IP)
2274				record = siar_valid(regs);
2275			else
2276				record = 1;
2277
2278			event->hw.last_period = event->hw.sample_period;
2279		}
2280		if (left < 0x80000000LL)
2281			val = 0x80000000LL - left;
2282	}
2283
2284	write_pmc(event->hw.idx, val);
2285	local64_set(&event->hw.prev_count, val);
2286	local64_set(&event->hw.period_left, left);
2287	perf_event_update_userpage(event);
2288
2289	/*
2290	 * Due to hardware limitation, sometimes SIAR could sample a kernel
2291	 * address even when freeze on supervisor state (kernel) is set in
2292	 * MMCR2. Check attr.exclude_kernel and address to drop the sample in
2293	 * these cases.
2294	 */
2295	if (event->attr.exclude_kernel &&
2296	    (event->attr.sample_type & PERF_SAMPLE_IP) &&
2297	    is_kernel_addr(mfspr(SPRN_SIAR)))
2298		record = 0;
2299
2300	/*
2301	 * Finally record data if requested.
2302	 */
2303	if (record) {
2304		struct perf_sample_data data;
2305
2306		perf_sample_data_init(&data, ~0ULL, event->hw.last_period);
2307
2308		if (event->attr.sample_type & PERF_SAMPLE_ADDR_TYPE)
2309			perf_get_data_addr(event, regs, &data.addr);
2310
2311		if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) {
2312			struct cpu_hw_events *cpuhw;
2313			cpuhw = this_cpu_ptr(&cpu_hw_events);
2314			power_pmu_bhrb_read(event, cpuhw);
2315			perf_sample_save_brstack(&data, event, &cpuhw->bhrb_stack, NULL);
2316		}
2317
2318		if (event->attr.sample_type & PERF_SAMPLE_DATA_SRC &&
2319						ppmu->get_mem_data_src) {
2320			ppmu->get_mem_data_src(&data.data_src, ppmu->flags, regs);
2321			data.sample_flags |= PERF_SAMPLE_DATA_SRC;
2322		}
2323
2324		if (event->attr.sample_type & PERF_SAMPLE_WEIGHT_TYPE &&
2325						ppmu->get_mem_weight) {
2326			ppmu->get_mem_weight(&data.weight.full, event->attr.sample_type);
2327			data.sample_flags |= PERF_SAMPLE_WEIGHT_TYPE;
2328		}
2329		if (perf_event_overflow(event, &data, regs))
2330			power_pmu_stop(event, 0);
2331	} else if (period) {
2332		/* Account for interrupt in case of invalid SIAR */
2333		if (perf_event_account_interrupt(event))
2334			power_pmu_stop(event, 0);
2335	}
2336}
2337
2338/*
2339 * Called from generic code to get the misc flags (i.e. processor mode)
2340 * for an event_id.
2341 */
2342unsigned long perf_misc_flags(struct pt_regs *regs)
2343{
2344	u32 flags = perf_get_misc_flags(regs);
2345
2346	if (flags)
2347		return flags;
2348	return user_mode(regs) ? PERF_RECORD_MISC_USER :
2349		PERF_RECORD_MISC_KERNEL;
2350}
2351
2352/*
2353 * Called from generic code to get the instruction pointer
2354 * for an event_id.
2355 */
2356unsigned long perf_instruction_pointer(struct pt_regs *regs)
2357{
2358	unsigned long siar = mfspr(SPRN_SIAR);
2359
2360	if (regs_use_siar(regs) && siar_valid(regs) && siar)
2361		return siar + perf_ip_adjust(regs);
2362	else
2363		return regs->nip;
2364}
2365
2366static bool pmc_overflow_power7(unsigned long val)
2367{
2368	/*
2369	 * Events on POWER7 can roll back if a speculative event doesn't
2370	 * eventually complete. Unfortunately in some rare cases they will
2371	 * raise a performance monitor exception. We need to catch this to
2372	 * ensure we reset the PMC. In all cases the PMC will be 256 or less
2373	 * cycles from overflow.
2374	 *
2375	 * We only do this if the first pass fails to find any overflowing
2376	 * PMCs because a user might set a period of less than 256 and we
2377	 * don't want to mistakenly reset them.
2378	 */
2379	if ((0x80000000 - val) <= 256)
2380		return true;
2381
2382	return false;
2383}
2384
2385static bool pmc_overflow(unsigned long val)
2386{
2387	if ((int)val < 0)
2388		return true;
2389
2390	return false;
2391}
2392
2393/*
2394 * Performance monitor interrupt stuff
2395 */
2396static void __perf_event_interrupt(struct pt_regs *regs)
2397{
2398	int i, j;
2399	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
2400	struct perf_event *event;
2401	int found, active;
2402
2403	if (cpuhw->n_limited)
2404		freeze_limited_counters(cpuhw, mfspr(SPRN_PMC5),
2405					mfspr(SPRN_PMC6));
2406
2407	perf_read_regs(regs);
2408
2409	/* Read all the PMCs since we'll need them a bunch of times */
2410	for (i = 0; i < ppmu->n_counter; ++i)
2411		cpuhw->pmcs[i] = read_pmc(i + 1);
2412
2413	/* Try to find what caused the IRQ */
2414	found = 0;
2415	for (i = 0; i < ppmu->n_counter; ++i) {
2416		if (!pmc_overflow(cpuhw->pmcs[i]))
2417			continue;
2418		if (is_limited_pmc(i + 1))
2419			continue; /* these won't generate IRQs */
2420		/*
2421		 * We've found one that's overflowed.  For active
2422		 * counters we need to log this.  For inactive
2423		 * counters, we need to reset it anyway
2424		 */
2425		found = 1;
2426		active = 0;
2427		for (j = 0; j < cpuhw->n_events; ++j) {
2428			event = cpuhw->event[j];
2429			if (event->hw.idx == (i + 1)) {
2430				active = 1;
2431				record_and_restart(event, cpuhw->pmcs[i], regs);
2432				break;
2433			}
2434		}
2435
2436		/*
2437		 * Clear PACA_IRQ_PMI in case it was set by
2438		 * set_pmi_irq_pending() when PMU was enabled
2439		 * after accounting for interrupts.
2440		 */
2441		clear_pmi_irq_pending();
2442
2443		if (!active)
2444			/* reset non active counters that have overflowed */
2445			write_pmc(i + 1, 0);
2446	}
2447	if (!found && pvr_version_is(PVR_POWER7)) {
2448		/* check active counters for special buggy p7 overflow */
2449		for (i = 0; i < cpuhw->n_events; ++i) {
2450			event = cpuhw->event[i];
2451			if (!event->hw.idx || is_limited_pmc(event->hw.idx))
2452				continue;
2453			if (pmc_overflow_power7(cpuhw->pmcs[event->hw.idx - 1])) {
2454				/* event has overflowed in a buggy way*/
2455				found = 1;
2456				record_and_restart(event,
2457						   cpuhw->pmcs[event->hw.idx - 1],
2458						   regs);
2459			}
2460		}
2461	}
2462
2463	/*
2464	 * During system wide profiling or while specific CPU is monitored for an
2465	 * event, some corner cases could cause PMC to overflow in idle path. This
2466	 * will trigger a PMI after waking up from idle. Since counter values are _not_
2467	 * saved/restored in idle path, can lead to below "Can't find PMC" message.
2468	 */
2469	if (unlikely(!found) && !arch_irq_disabled_regs(regs))
2470		printk_ratelimited(KERN_WARNING "Can't find PMC that caused IRQ\n");
2471
2472	/*
2473	 * Reset MMCR0 to its normal value.  This will set PMXE and
2474	 * clear FC (freeze counters) and PMAO (perf mon alert occurred)
2475	 * and thus allow interrupts to occur again.
2476	 * XXX might want to use MSR.PM to keep the events frozen until
2477	 * we get back out of this interrupt.
2478	 */
2479	write_mmcr0(cpuhw, cpuhw->mmcr.mmcr0);
2480
2481	/* Clear the cpuhw->pmcs */
2482	memset(&cpuhw->pmcs, 0, sizeof(cpuhw->pmcs));
2483
2484}
2485
2486static void perf_event_interrupt(struct pt_regs *regs)
2487{
2488	u64 start_clock = sched_clock();
2489
2490	__perf_event_interrupt(regs);
2491	perf_sample_event_took(sched_clock() - start_clock);
2492}
2493
2494static int power_pmu_prepare_cpu(unsigned int cpu)
2495{
2496	struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);
2497
2498	if (ppmu) {
2499		memset(cpuhw, 0, sizeof(*cpuhw));
2500		cpuhw->mmcr.mmcr0 = MMCR0_FC;
2501	}
2502	return 0;
2503}
2504
2505static ssize_t pmu_name_show(struct device *cdev,
2506		struct device_attribute *attr,
2507		char *buf)
2508{
2509	if (ppmu)
2510		return sysfs_emit(buf, "%s", ppmu->name);
2511
2512	return 0;
2513}
2514
2515static DEVICE_ATTR_RO(pmu_name);
2516
2517static struct attribute *pmu_caps_attrs[] = {
2518	&dev_attr_pmu_name.attr,
2519	NULL
2520};
2521
2522static const struct attribute_group pmu_caps_group = {
2523	.name  = "caps",
2524	.attrs = pmu_caps_attrs,
2525};
2526
2527static const struct attribute_group *pmu_caps_groups[] = {
2528	&pmu_caps_group,
2529	NULL,
2530};
2531
2532int __init register_power_pmu(struct power_pmu *pmu)
2533{
2534	if (ppmu)
2535		return -EBUSY;		/* something's already registered */
2536
2537	ppmu = pmu;
2538	pr_info("%s performance monitor hardware support registered\n",
2539		pmu->name);
2540
2541	power_pmu.attr_groups = ppmu->attr_groups;
2542
2543	if (ppmu->flags & PPMU_ARCH_207S)
2544		power_pmu.attr_update = pmu_caps_groups;
2545
2546	power_pmu.capabilities |= (ppmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS);
2547
2548#ifdef MSR_HV
2549	/*
2550	 * Use FCHV to ignore kernel events if MSR.HV is set.
2551	 */
2552	if (mfmsr() & MSR_HV)
2553		freeze_events_kernel = MMCR0_FCHV;
2554#endif /* CONFIG_PPC64 */
2555
2556	perf_pmu_register(&power_pmu, "cpu", PERF_TYPE_RAW);
2557	cpuhp_setup_state(CPUHP_PERF_POWER, "perf/powerpc:prepare",
2558			  power_pmu_prepare_cpu, NULL);
2559	return 0;
2560}
2561
2562#ifdef CONFIG_PPC64
2563static bool pmu_override = false;
2564static unsigned long pmu_override_val;
2565static void do_pmu_override(void *data)
2566{
2567	ppc_set_pmu_inuse(1);
2568	if (pmu_override_val)
2569		mtspr(SPRN_MMCR1, pmu_override_val);
2570	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_FC);
2571}
2572
2573static int __init init_ppc64_pmu(void)
2574{
2575	if (cpu_has_feature(CPU_FTR_HVMODE) && pmu_override) {
2576		pr_warn("disabling perf due to pmu_override= command line option.\n");
2577		on_each_cpu(do_pmu_override, NULL, 1);
2578		return 0;
2579	}
2580
2581	/* run through all the pmu drivers one at a time */
2582	if (!init_power5_pmu())
2583		return 0;
2584	else if (!init_power5p_pmu())
2585		return 0;
2586	else if (!init_power6_pmu())
2587		return 0;
2588	else if (!init_power7_pmu())
2589		return 0;
2590	else if (!init_power8_pmu())
2591		return 0;
2592	else if (!init_power9_pmu())
2593		return 0;
2594	else if (!init_power10_pmu())
 
 
2595		return 0;
2596	else if (!init_ppc970_pmu())
2597		return 0;
2598	else
2599		return init_generic_compat_pmu();
2600}
2601early_initcall(init_ppc64_pmu);
2602
2603static int __init pmu_setup(char *str)
2604{
2605	unsigned long val;
2606
2607	if (!early_cpu_has_feature(CPU_FTR_HVMODE))
2608		return 0;
2609
2610	pmu_override = true;
2611
2612	if (kstrtoul(str, 0, &val))
2613		val = 0;
2614
2615	pmu_override_val = val;
2616
2617	return 1;
2618}
2619__setup("pmu_override=", pmu_setup);
2620
2621#endif