diff options
Diffstat (limited to 'arch/powerpc/perf/core-book3s.c')
| -rw-r--r-- | arch/powerpc/perf/core-book3s.c | 2296 |
1 files changed, 2296 insertions, 0 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c new file mode 100644 index 000000000..091bdeaf0 --- /dev/null +++ b/arch/powerpc/perf/core-book3s.c @@ -0,0 +1,2296 @@ +/* + * Performance event support - powerpc architecture code + * + * Copyright 2008-2009 Paul Mackerras, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/perf_event.h> +#include <linux/percpu.h> +#include <linux/hardirq.h> +#include <linux/uaccess.h> +#include <asm/reg.h> +#include <asm/pmc.h> +#include <asm/machdep.h> +#include <asm/firmware.h> +#include <asm/ptrace.h> +#include <asm/code-patching.h> + +#define BHRB_MAX_ENTRIES 32 +#define BHRB_TARGET 0x0000000000000002 +#define BHRB_PREDICTION 0x0000000000000001 +#define BHRB_EA 0xFFFFFFFFFFFFFFFCUL + +struct cpu_hw_events { + int n_events; + int n_percpu; + int disabled; + int n_added; + int n_limited; + u8 pmcs_enabled; + struct perf_event *event[MAX_HWEVENTS]; + u64 events[MAX_HWEVENTS]; + unsigned int flags[MAX_HWEVENTS]; + /* + * The order of the MMCR array is: + * - 64-bit, MMCR0, MMCR1, MMCRA, MMCR2 + * - 32-bit, MMCR0, MMCR1, MMCR2 + */ + unsigned long mmcr[4]; + struct perf_event *limited_counter[MAX_LIMITED_HWCOUNTERS]; + u8 limited_hwidx[MAX_LIMITED_HWCOUNTERS]; + u64 alternatives[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; + unsigned long amasks[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; + unsigned long avalues[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; + + unsigned int txn_flags; + int n_txn_start; + + /* BHRB bits */ + u64 bhrb_filter; /* BHRB HW branch filter */ + unsigned int bhrb_users; + void *bhrb_context; + struct perf_branch_stack bhrb_stack; + struct perf_branch_entry bhrb_entries[BHRB_MAX_ENTRIES]; + u64 ic_init; +}; + +static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); + +static struct power_pmu *ppmu; + +/* + * Normally, to ignore kernel events we set the FCS (freeze counters + * in supervisor mode) bit in MMCR0, but if the kernel runs with the + * hypervisor bit set in the MSR, or if we are running on a processor + * where the hypervisor bit is forced to 1 (as on Apple G5 processors), + * then we need to use the FCHV bit to ignore kernel events. + */ +static unsigned int freeze_events_kernel = MMCR0_FCS; + +/* + * 32-bit doesn't have MMCRA but does have an MMCR2, + * and a few other names are different. + */ +#ifdef CONFIG_PPC32 + +#define MMCR0_FCHV 0 +#define MMCR0_PMCjCE MMCR0_PMCnCE +#define MMCR0_FC56 0 +#define MMCR0_PMAO 0 +#define MMCR0_EBE 0 +#define MMCR0_BHRBA 0 +#define MMCR0_PMCC 0 +#define MMCR0_PMCC_U6 0 + +#define SPRN_MMCRA SPRN_MMCR2 +#define MMCRA_SAMPLE_ENABLE 0 + +static inline unsigned long perf_ip_adjust(struct pt_regs *regs) +{ + return 0; +} +static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp) { } +static inline u32 perf_get_misc_flags(struct pt_regs *regs) +{ + return 0; +} +static inline void perf_read_regs(struct pt_regs *regs) +{ + regs->result = 0; +} +static inline int perf_intr_is_nmi(struct pt_regs *regs) +{ + return 0; +} + +static inline int siar_valid(struct pt_regs *regs) +{ + return 1; +} + +static bool is_ebb_event(struct perf_event *event) { return false; } +static int ebb_event_check(struct perf_event *event) { return 0; } +static void ebb_event_add(struct perf_event *event) { } +static void ebb_switch_out(unsigned long mmcr0) { } +static unsigned long ebb_switch_in(bool ebb, struct cpu_hw_events *cpuhw) +{ + return cpuhw->mmcr[0]; +} + +static inline void power_pmu_bhrb_enable(struct perf_event *event) {} +static inline void power_pmu_bhrb_disable(struct perf_event *event) {} +static void power_pmu_sched_task(struct perf_event_context *ctx, bool sched_in) {} +static inline void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) {} +static void pmao_restore_workaround(bool ebb) { } +#endif /* CONFIG_PPC32 */ + +static bool regs_use_siar(struct pt_regs *regs) +{ + /* + * When we take a performance monitor exception the regs are setup + * using perf_read_regs() which overloads some fields, in particular + * regs->result to tell us whether to use SIAR. + * + * However if the regs are from another exception, eg. a syscall, then + * they have not been setup using perf_read_regs() and so regs->result + * is something random. + */ + return ((TRAP(regs) == 0xf00) && regs->result); +} + +/* + * Things that are specific to 64-bit implementations. + */ +#ifdef CONFIG_PPC64 + +static inline unsigned long perf_ip_adjust(struct pt_regs *regs) +{ + unsigned long mmcra = regs->dsisr; + + if ((ppmu->flags & PPMU_HAS_SSLOT) && (mmcra & MMCRA_SAMPLE_ENABLE)) { + unsigned long slot = (mmcra & MMCRA_SLOT) >> MMCRA_SLOT_SHIFT; + if (slot > 1) + return 4 * (slot - 1); + } + + return 0; +} + +/* + * The user wants a data address recorded. + * If we're not doing instruction sampling, give them the SDAR + * (sampled data address). If we are doing instruction sampling, then + * only give them the SDAR if it corresponds to the instruction + * pointed to by SIAR; this is indicated by the [POWER6_]MMCRA_SDSYNC, the + * [POWER7P_]MMCRA_SDAR_VALID bit in MMCRA, or the SDAR_VALID bit in SIER. + */ +static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp) +{ + unsigned long mmcra = regs->dsisr; + bool sdar_valid; + + if (ppmu->flags & PPMU_HAS_SIER) + sdar_valid = regs->dar & SIER_SDAR_VALID; + else { + unsigned long sdsync; + + if (ppmu->flags & PPMU_SIAR_VALID) + sdsync = POWER7P_MMCRA_SDAR_VALID; + else if (ppmu->flags & PPMU_ALT_SIPR) + sdsync = POWER6_MMCRA_SDSYNC; + else if (ppmu->flags & PPMU_NO_SIAR) + sdsync = MMCRA_SAMPLE_ENABLE; + else + sdsync = MMCRA_SDSYNC; + + sdar_valid = mmcra & sdsync; + } + + if (!(mmcra & MMCRA_SAMPLE_ENABLE) || sdar_valid) + *addrp = mfspr(SPRN_SDAR); + + if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN) && + is_kernel_addr(mfspr(SPRN_SDAR))) + *addrp = 0; +} + +static bool regs_sihv(struct pt_regs *regs) +{ + unsigned long sihv = MMCRA_SIHV; + + if (ppmu->flags & PPMU_HAS_SIER) + return !!(regs->dar & SIER_SIHV); + + if (ppmu->flags & PPMU_ALT_SIPR) + sihv = POWER6_MMCRA_SIHV; + + return !!(regs->dsisr & sihv); +} + +static bool regs_sipr(struct pt_regs *regs) +{ + unsigned long sipr = MMCRA_SIPR; + + if (ppmu->flags & PPMU_HAS_SIER) + return !!(regs->dar & SIER_SIPR); + + if (ppmu->flags & PPMU_ALT_SIPR) + sipr = POWER6_MMCRA_SIPR; + + return !!(regs->dsisr & sipr); +} + +static inline u32 perf_flags_from_msr(struct pt_regs *regs) +{ + if (regs->msr & MSR_PR) + return PERF_RECORD_MISC_USER; + if ((regs->msr & MSR_HV) && freeze_events_kernel != MMCR0_FCHV) + return PERF_RECORD_MISC_HYPERVISOR; + return PERF_RECORD_MISC_KERNEL; +} + +static inline u32 perf_get_misc_flags(struct pt_regs *regs) +{ + bool use_siar = regs_use_siar(regs); + + if (!use_siar) + return perf_flags_from_msr(regs); + + /* + * If we don't have flags in MMCRA, rather than using + * the MSR, we intuit the flags from the address in + * SIAR which should give slightly more reliable + * results + */ + if (ppmu->flags & PPMU_NO_SIPR) { + unsigned long siar = mfspr(SPRN_SIAR); + if (is_kernel_addr(siar)) + return PERF_RECORD_MISC_KERNEL; + return PERF_RECORD_MISC_USER; + } + + /* PR has priority over HV, so order below is important */ + if (regs_sipr(regs)) + return PERF_RECORD_MISC_USER; + + if (regs_sihv(regs) && (freeze_events_kernel != MMCR0_FCHV)) + return PERF_RECORD_MISC_HYPERVISOR; + + return PERF_RECORD_MISC_KERNEL; +} + +/* + * Overload regs->dsisr to store MMCRA so we only need to read it once + * on each interrupt. + * Overload regs->dar to store SIER if we have it. + * Overload regs->result to specify whether we should use the MSR (result + * is zero) or the SIAR (result is non zero). + */ +static inline void perf_read_regs(struct pt_regs *regs) +{ + unsigned long mmcra = mfspr(SPRN_MMCRA); + int marked = mmcra & MMCRA_SAMPLE_ENABLE; + int use_siar; + + regs->dsisr = mmcra; + + if (ppmu->flags & PPMU_HAS_SIER) + regs->dar = mfspr(SPRN_SIER); + + /* + * If this isn't a PMU exception (eg a software event) the SIAR is + * not valid. Use pt_regs. + * + * If it is a marked event use the SIAR. + * + * If the PMU doesn't update the SIAR for non marked events use + * pt_regs. + * + * If the PMU has HV/PR flags then check to see if they + * place the exception in userspace. If so, use pt_regs. In + * continuous sampling mode the SIAR and the PMU exception are + * not synchronised, so they may be many instructions apart. + * This can result in confusing backtraces. We still want + * hypervisor samples as well as samples in the kernel with + * interrupts off hence the userspace check. + */ + if (TRAP(regs) != 0xf00) + use_siar = 0; + else if ((ppmu->flags & PPMU_NO_SIAR)) + use_siar = 0; + else if (marked) + use_siar = 1; + else if ((ppmu->flags & PPMU_NO_CONT_SAMPLING)) + use_siar = 0; + else if (!(ppmu->flags & PPMU_NO_SIPR) && regs_sipr(regs)) + use_siar = 0; + else + use_siar = 1; + + regs->result = use_siar; +} + +/* + * If interrupts were soft-disabled when a PMU interrupt occurs, treat + * it as an NMI. + */ +static inline int perf_intr_is_nmi(struct pt_regs *regs) +{ + return (regs->softe & IRQS_DISABLED); +} + +/* + * On processors like P7+ that have the SIAR-Valid bit, marked instructions + * must be sampled only if the SIAR-valid bit is set. + * + * For unmarked instructions and for processors that don't have the SIAR-Valid + * bit, assume that SIAR is valid. + */ +static inline int siar_valid(struct pt_regs *regs) +{ + unsigned long mmcra = regs->dsisr; + int marked = mmcra & MMCRA_SAMPLE_ENABLE; + + if (marked) { + if (ppmu->flags & PPMU_HAS_SIER) + return regs->dar & SIER_SIAR_VALID; + + if (ppmu->flags & PPMU_SIAR_VALID) + return mmcra & POWER7P_MMCRA_SIAR_VALID; + } + + return 1; +} + + +/* Reset all possible BHRB entries */ +static void power_pmu_bhrb_reset(void) +{ + asm volatile(PPC_CLRBHRB); +} + +static void power_pmu_bhrb_enable(struct perf_event *event) +{ + struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events); + + if (!ppmu->bhrb_nr) + return; + + /* Clear BHRB if we changed task context to avoid data leaks */ + if (event->ctx->task && cpuhw->bhrb_context != event->ctx) { + power_pmu_bhrb_reset(); + cpuhw->bhrb_context = event->ctx; + } + cpuhw->bhrb_users++; + perf_sched_cb_inc(event->ctx->pmu); +} + +static void power_pmu_bhrb_disable(struct perf_event *event) +{ + struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events); + + if (!ppmu->bhrb_nr) + return; + + WARN_ON_ONCE(!cpuhw->bhrb_users); + cpuhw->bhrb_users--; + perf_sched_cb_dec(event->ctx->pmu); + + if (!cpuhw->disabled && !cpuhw->bhrb_users) { + /* BHRB cannot be turned off when other + * events are active on the PMU. + */ + + /* avoid stale pointer */ + cpuhw->bhrb_context = NULL; + } +} + +/* Called from ctxsw to prevent one process's branch entries to + * mingle with the other process's entries during context switch. + */ +static void power_pmu_sched_task(struct perf_event_context *ctx, bool sched_in) +{ + if (!ppmu->bhrb_nr) + return; + + if (sched_in) + power_pmu_bhrb_reset(); +} +/* Calculate the to address for a branch */ +static __u64 power_pmu_bhrb_to(u64 addr) +{ + unsigned int instr; + int ret; + __u64 target; + + if (is_kernel_addr(addr)) { + if (probe_kernel_read(&instr, (void *)addr, sizeof(instr))) + return 0; + + return branch_target(&instr); + } + + /* Userspace: need copy instruction here then translate it */ + pagefault_disable(); + ret = __get_user_inatomic(instr, (unsigned int __user *)addr); + if (ret) { + pagefault_enable(); + return 0; + } + pagefault_enable(); + + target = branch_target(&instr); + if ((!target) || (instr & BRANCH_ABSOLUTE)) + return target; + + /* Translate relative branch target from kernel to user address */ + return target - (unsigned long)&instr + addr; +} + +/* Processing BHRB entries */ +static void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) +{ + u64 val; + u64 addr; + int r_index, u_index, pred; + + r_index = 0; + u_index = 0; + while (r_index < ppmu->bhrb_nr) { + /* Assembly read function */ + val = read_bhrb(r_index++); + if (!val) + /* Terminal marker: End of valid BHRB entries */ + break; + else { + addr = val & BHRB_EA; + pred = val & BHRB_PREDICTION; + + if (!addr) + /* invalid entry */ + continue; + + /* + * BHRB rolling buffer could very much contain the kernel + * addresses at this point. Check the privileges before + * exporting it to userspace (avoid exposure of regions + * where we could have speculative execution) + */ + if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN) && + is_kernel_addr(addr)) + continue; + + /* Branches are read most recent first (ie. mfbhrb 0 is + * the most recent branch). + * There are two types of valid entries: + * 1) a target entry which is the to address of a + * computed goto like a blr,bctr,btar. The next + * entry read from the bhrb will be branch + * corresponding to this target (ie. the actual + * blr/bctr/btar instruction). + * 2) a from address which is an actual branch. If a + * target entry proceeds this, then this is the + * matching branch for that target. If this is not + * following a target entry, then this is a branch + * where the target is given as an immediate field + * in the instruction (ie. an i or b form branch). + * In this case we need to read the instruction from + * memory to determine the target/to address. + */ + + if (val & BHRB_TARGET) { + /* Target branches use two entries + * (ie. computed gotos/XL form) + */ + cpuhw->bhrb_entries[u_index].to = addr; + cpuhw->bhrb_entries[u_index].mispred = pred; + cpuhw->bhrb_entries[u_index].predicted = ~pred; + + /* Get from address in next entry */ + val = read_bhrb(r_index++); + addr = val & BHRB_EA; + if (val & BHRB_TARGET) { + /* Shouldn't have two targets in a + row.. Reset index and try again */ + r_index--; + addr = 0; + } + cpuhw->bhrb_entries[u_index].from = addr; + } else { + /* Branches to immediate field + (ie I or B form) */ + cpuhw->bhrb_entries[u_index].from = addr; + cpuhw->bhrb_entries[u_index].to = + power_pmu_bhrb_to(addr); + cpuhw->bhrb_entries[u_index].mispred = pred; + cpuhw->bhrb_entries[u_index].predicted = ~pred; + } + u_index++; + + } + } + cpuhw->bhrb_stack.nr = u_index; + return; +} + +static bool is_ebb_event(struct perf_event *event) +{ + /* + * This could be a per-PMU callback, but we'd rather avoid the cost. We + * check that the PMU supports EBB, meaning those that don't can still + * use bit 63 of the event code for something else if they wish. + */ + return (ppmu->flags & PPMU_ARCH_207S) && + ((event->attr.config >> PERF_EVENT_CONFIG_EBB_SHIFT) & 1); +} + +static int ebb_event_check(struct perf_event *event) +{ + struct perf_event *leader = event->group_leader; + + /* Event and group leader must agree on EBB */ + if (is_ebb_event(leader) != is_ebb_event(event)) + return -EINVAL; + + if (is_ebb_event(event)) { + if (!(event->attach_state & PERF_ATTACH_TASK)) + return -EINVAL; + + if (!leader->attr.pinned || !leader->attr.exclusive) + return -EINVAL; + + if (event->attr.freq || + event->attr.inherit || + event->attr.sample_type || + event->attr.sample_period || + event->attr.enable_on_exec) + return -EINVAL; + } + + return 0; +} + +static void ebb_event_add(struct perf_event *event) +{ + if (!is_ebb_event(event) || current->thread.used_ebb) + return; + + /* + * IFF this is the first time we've added an EBB event, set + * PMXE in the user MMCR0 so we can detect when it's cleared by + * userspace. We need this so that we can context switch while + * userspace is in the EBB handler (where PMXE is 0). + */ + current->thread.used_ebb = 1; + current->thread.mmcr0 |= MMCR0_PMXE; +} + +static void ebb_switch_out(unsigned long mmcr0) +{ + if (!(mmcr0 & MMCR0_EBE)) + return; + + current->thread.siar = mfspr(SPRN_SIAR); + current->thread.sier = mfspr(SPRN_SIER); + current->thread.sdar = mfspr(SPRN_SDAR); + current->thread.mmcr0 = mmcr0 & MMCR0_USER_MASK; + current->thread.mmcr2 = mfspr(SPRN_MMCR2) & MMCR2_USER_MASK; +} + +static unsigned long ebb_switch_in(bool ebb, struct cpu_hw_events *cpuhw) +{ + unsigned long mmcr0 = cpuhw->mmcr[0]; + + if (!ebb) + goto out; + + /* Enable EBB and read/write to all 6 PMCs and BHRB for userspace */ + mmcr0 |= MMCR0_EBE | MMCR0_BHRBA | MMCR0_PMCC_U6; + + /* + * Add any bits from the user MMCR0, FC or PMAO. This is compatible + * with pmao_restore_workaround() because we may add PMAO but we never + * clear it here. + */ + mmcr0 |= current->thread.mmcr0; + + /* + * Be careful not to set PMXE if userspace had it cleared. This is also + * compatible with pmao_restore_workaround() because it has already + * cleared PMXE and we leave PMAO alone. + */ + if (!(current->thread.mmcr0 & MMCR0_PMXE)) + mmcr0 &= ~MMCR0_PMXE; + + mtspr(SPRN_SIAR, current->thread.siar); + mtspr(SPRN_SIER, current->thread.sier); + mtspr(SPRN_SDAR, current->thread.sdar); + + /* + * Merge the kernel & user values of MMCR2. The semantics we implement + * are that the user MMCR2 can set bits, ie. cause counters to freeze, + * but not clear bits. If a task wants to be able to clear bits, ie. + * unfreeze counters, it should not set exclude_xxx in its events and + * instead manage the MMCR2 entirely by itself. + */ + mtspr(SPRN_MMCR2, cpuhw->mmcr[3] | current->thread.mmcr2); +out: + return mmcr0; +} + +static void pmao_restore_workaround(bool ebb) +{ + unsigned pmcs[6]; + + if (!cpu_has_feature(CPU_FTR_PMAO_BUG)) + return; + + /* + * On POWER8E there is a hardware defect which affects the PMU context + * switch logic, ie. power_pmu_disable/enable(). + * + * When a counter overflows PMXE is cleared and FC/PMAO is set in MMCR0 + * by the hardware. Sometime later the actual PMU exception is + * delivered. + * + * If we context switch, or simply disable/enable, the PMU prior to the + * exception arriving, the exception will be lost when we clear PMAO. + * + * When we reenable the PMU, we will write the saved MMCR0 with PMAO + * set, and this _should_ generate an exception. However because of the + * defect no exception is generated when we write PMAO, and we get + * stuck with no counters counting but no exception delivered. + * + * The workaround is to detect this case and tweak the hardware to + * create another pending PMU exception. + * + * We do that by setting up PMC6 (cycles) for an imminent overflow and + * enabling the PMU. That causes a new exception to be generated in the + * chip, but we don't take it yet because we have interrupts hard + * disabled. We then write back the PMU state as we want it to be seen + * by the exception handler. When we reenable interrupts the exception + * handler will be called and see the correct state. + * + * The logic is the same for EBB, except that the exception is gated by + * us having interrupts hard disabled as well as the fact that we are + * not in userspace. The exception is finally delivered when we return + * to userspace. + */ + + /* Only if PMAO is set and PMAO_SYNC is clear */ + if ((current->thread.mmcr0 & (MMCR0_PMAO | MMCR0_PMAO_SYNC)) != MMCR0_PMAO) + return; + + /* If we're doing EBB, only if BESCR[GE] is set */ + if (ebb && !(current->thread.bescr & BESCR_GE)) + return; + + /* + * We are already soft-disabled in power_pmu_enable(). We need to hard + * disable to actually prevent the PMU exception from firing. + */ + hard_irq_disable(); + + /* + * This is a bit gross, but we know we're on POWER8E and have 6 PMCs. + * Using read/write_pmc() in a for loop adds 12 function calls and + * almost doubles our code size. + */ + pmcs[0] = mfspr(SPRN_PMC1); + pmcs[1] = mfspr(SPRN_PMC2); + pmcs[2] = mfspr(SPRN_PMC3); + pmcs[3] = mfspr(SPRN_PMC4); + pmcs[4] = mfspr(SPRN_PMC5); + pmcs[5] = mfspr(SPRN_PMC6); + + /* Ensure all freeze bits are unset */ + mtspr(SPRN_MMCR2, 0); + + /* Set up PMC6 to overflow in one cycle */ + mtspr(SPRN_PMC6, 0x7FFFFFFE); + + /* Enable exceptions and unfreeze PMC6 */ + mtspr(SPRN_MMCR0, MMCR0_PMXE | MMCR0_PMCjCE | MMCR0_PMAO); + + /* Now we need to refreeze and restore the PMCs */ + mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMAO); + + mtspr(SPRN_PMC1, pmcs[0]); + mtspr(SPRN_PMC2, pmcs[1]); + mtspr(SPRN_PMC3, pmcs[2]); + mtspr(SPRN_PMC4, pmcs[3]); + mtspr(SPRN_PMC5, pmcs[4]); + mtspr(SPRN_PMC6, pmcs[5]); +} + +#endif /* CONFIG_PPC64 */ + +static void perf_event_interrupt(struct pt_regs *regs); + +/* + * Read one performance monitor counter (PMC). + */ +static unsigned long read_pmc(int idx) +{ + unsigned long val; + + switch (idx) { + case 1: + val = mfspr(SPRN_PMC1); + break; + case 2: + val = mfspr(SPRN_PMC2); + break; + case 3: + val = mfspr(SPRN_PMC3); + break; + case 4: + val = mfspr(SPRN_PMC4); + break; + case 5: + val = mfspr(SPRN_PMC5); + break; + case 6: + val = mfspr(SPRN_PMC6); + break; +#ifdef CONFIG_PPC64 + case 7: + val = mfspr(SPRN_PMC7); + break; + case 8: + val = mfspr(SPRN_PMC8); + break; +#endif /* CONFIG_PPC64 */ + default: + printk(KERN_ERR "oops trying to read PMC%d\n", idx); + val = 0; + } + return val; +} + +/* + * Write one PMC. + */ +static void write_pmc(int idx, unsigned long val) +{ + switch (idx) { + case 1: + mtspr(SPRN_PMC1, val); + break; + case 2: + mtspr(SPRN_PMC2, val); + break; + case 3: + mtspr(SPRN_PMC3, val); + break; + case 4: + mtspr(SPRN_PMC4, val); + break; + case 5: + mtspr(SPRN_PMC5, val); + break; + case 6: + mtspr(SPRN_PMC6, val); + break; +#ifdef CONFIG_PPC64 + case 7: + mtspr(SPRN_PMC7, val); + break; + case 8: + mtspr(SPRN_PMC8, val); + break; +#endif /* CONFIG_PPC64 */ + default: + printk(KERN_ERR "oops trying to write PMC%d\n", idx); + } +} + +/* Called from sysrq_handle_showregs() */ +void perf_event_print_debug(void) +{ + unsigned long sdar, sier, flags; + u32 pmcs[MAX_HWEVENTS]; + int i; + + if (!ppmu) { + pr_info("Performance monitor hardware not registered.\n"); + return; + } + + if (!ppmu->n_counter) + return; + + local_irq_save(flags); + + pr_info("CPU: %d PMU registers, ppmu = %s n_counters = %d", + smp_processor_id(), ppmu->name, ppmu->n_counter); + + for (i = 0; i < ppmu->n_counter; i++) + pmcs[i] = read_pmc(i + 1); + + for (; i < MAX_HWEVENTS; i++) + pmcs[i] = 0xdeadbeef; + + pr_info("PMC1: %08x PMC2: %08x PMC3: %08x PMC4: %08x\n", + pmcs[0], pmcs[1], pmcs[2], pmcs[3]); + + if (ppmu->n_counter > 4) + pr_info("PMC5: %08x PMC6: %08x PMC7: %08x PMC8: %08x\n", + pmcs[4], pmcs[5], pmcs[6], pmcs[7]); + + pr_info("MMCR0: %016lx MMCR1: %016lx MMCRA: %016lx\n", + mfspr(SPRN_MMCR0), mfspr(SPRN_MMCR1), mfspr(SPRN_MMCRA)); + + sdar = sier = 0; +#ifdef CONFIG_PPC64 + sdar = mfspr(SPRN_SDAR); + + if (ppmu->flags & PPMU_HAS_SIER) + sier = mfspr(SPRN_SIER); + + if (ppmu->flags & PPMU_ARCH_207S) { + pr_info("MMCR2: %016lx EBBHR: %016lx\n", + mfspr(SPRN_MMCR2), mfspr(SPRN_EBBHR)); + pr_info("EBBRR: %016lx BESCR: %016lx\n", + mfspr(SPRN_EBBRR), mfspr(SPRN_BESCR)); + } +#endif + pr_info("SIAR: %016lx SDAR: %016lx SIER: %016lx\n", + mfspr(SPRN_SIAR), sdar, sier); + + local_irq_restore(flags); +} + +/* + * Check if a set of events can all go on the PMU at once. + * If they can't, this will look at alternative codes for the events + * and see if any combination of alternative codes is feasible. + * The feasible set is returned in event_id[]. + */ +static int power_check_constraints(struct cpu_hw_events *cpuhw, + u64 event_id[], unsigned int cflags[], + int n_ev) +{ + unsigned long mask, value, nv; + unsigned long smasks[MAX_HWEVENTS], svalues[MAX_HWEVENTS]; + int n_alt[MAX_HWEVENTS], choice[MAX_HWEVENTS]; + int i, j; + unsigned long addf = ppmu->add_fields; + unsigned long tadd = ppmu->test_adder; + + if (n_ev > ppmu->n_counter) + return -1; + + /* First see if the events will go on as-is */ + for (i = 0; i < n_ev; ++i) { + if ((cflags[i] & PPMU_LIMITED_PMC_REQD) + && !ppmu->limited_pmc_event(event_id[i])) { + ppmu->get_alternatives(event_id[i], cflags[i], + cpuhw->alternatives[i]); + event_id[i] = cpuhw->alternatives[i][0]; + } + if (ppmu->get_constraint(event_id[i], &cpuhw->amasks[i][0], + &cpuhw->avalues[i][0])) + return -1; + } + value = mask = 0; + for (i = 0; i < n_ev; ++i) { + nv = (value | cpuhw->avalues[i][0]) + + (value & cpuhw->avalues[i][0] & addf); + if ((((nv + tadd) ^ value) & mask) != 0 || + (((nv + tadd) ^ cpuhw->avalues[i][0]) & + cpuhw->amasks[i][0]) != 0) + break; + value = nv; + mask |= cpuhw->amasks[i][0]; + } + if (i == n_ev) + return 0; /* all OK */ + + /* doesn't work, gather alternatives... */ + if (!ppmu->get_alternatives) + return -1; + for (i = 0; i < n_ev; ++i) { + choice[i] = 0; + n_alt[i] = ppmu->get_alternatives(event_id[i], cflags[i], + cpuhw->alternatives[i]); + for (j = 1; j < n_alt[i]; ++j) + ppmu->get_constraint(cpuhw->alternatives[i][j], + &cpuhw->amasks[i][j], + &cpuhw->avalues[i][j]); + } + + /* enumerate all possibilities and see if any will work */ + i = 0; + j = -1; + value = mask = nv = 0; + while (i < n_ev) { + if (j >= 0) { + /* we're backtracking, restore context */ + value = svalues[i]; + mask = smasks[i]; + j = choice[i]; + } + /* + * See if any alternative k for event_id i, + * where k > j, will satisfy the constraints. + */ + while (++j < n_alt[i]) { + nv = (value | cpuhw->avalues[i][j]) + + (value & cpuhw->avalues[i][j] & addf); + if ((((nv + tadd) ^ value) & mask) == 0 && + (((nv + tadd) ^ cpuhw->avalues[i][j]) + & cpuhw->amasks[i][j]) == 0) + break; + } + if (j >= n_alt[i]) { + /* + * No feasible alternative, backtrack + * to event_id i-1 and continue enumerating its + * alternatives from where we got up to. + */ + if (--i < 0) + return -1; + } else { + /* + * Found a feasible alternative for event_id i, + * remember where we got up to with this event_id, + * go on to the next event_id, and start with + * the first alternative for it. + */ + choice[i] = j; + svalues[i] = value; + smasks[i] = mask; + value = nv; + mask |= cpuhw->amasks[i][j]; + ++i; + j = -1; + } + } + + /* OK, we have a feasible combination, tell the caller the solution */ + for (i = 0; i < n_ev; ++i) + event_id[i] = cpuhw->alternatives[i][choice[i]]; + return 0; +} + +/* + * Check if newly-added events have consistent settings for + * exclude_{user,kernel,hv} with each other and any previously + * added events. + */ +static int check_excludes(struct perf_event **ctrs, unsigned int cflags[], + int n_prev, int n_new) +{ + int eu = 0, ek = 0, eh = 0; + int i, n, first; + struct perf_event *event; + + /* + * If the PMU we're on supports per event exclude settings then we + * don't need to do any of this logic. NB. This assumes no PMU has both + * per event exclude and limited PMCs. + */ + if (ppmu->flags & PPMU_ARCH_207S) + return 0; + + n = n_prev + n_new; + if (n <= 1) + return 0; + + first = 1; + for (i = 0; i < n; ++i) { + if (cflags[i] & PPMU_LIMITED_PMC_OK) { + cflags[i] &= ~PPMU_LIMITED_PMC_REQD; + continue; + } + event = ctrs[i]; + if (first) { + eu = event->attr.exclude_user; + ek = event->attr.exclude_kernel; + eh = event->attr.exclude_hv; + first = 0; + } else if (event->attr.exclude_user != eu || + event->attr.exclude_kernel != ek || + event->attr.exclude_hv != eh) { + return -EAGAIN; + } + } + + if (eu || ek || eh) + for (i = 0; i < n; ++i) + if (cflags[i] & PPMU_LIMITED_PMC_OK) + cflags[i] |= PPMU_LIMITED_PMC_REQD; + + return 0; +} + +static u64 check_and_compute_delta(u64 prev, u64 val) +{ + u64 delta = (val - prev) & 0xfffffffful; + + /* + * POWER7 can roll back counter values, if the new value is smaller + * than the previous value it will cause the delta and the counter to + * have bogus values unless we rolled a counter over. If a coutner is + * rolled back, it will be smaller, but within 256, which is the maximum + * number of events to rollback at once. If we detect a rollback + * return 0. This can lead to a small lack of precision in the + * counters. + */ + if (prev > val && (prev - val) < 256) + delta = 0; + + return delta; +} + +static void power_pmu_read(struct perf_event *event) +{ + s64 val, delta, prev; + + if (event->hw.state & PERF_HES_STOPPED) + return; + + if (!event->hw.idx) + return; + + if (is_ebb_event(event)) { + val = read_pmc(event->hw.idx); + local64_set(&event->hw.prev_count, val); + return; + } + + /* + * Performance monitor interrupts come even when interrupts + * are soft-disabled, as long as interrupts are hard-enabled. + * Therefore we treat them like NMIs. + */ + do { + prev = local64_read(&event->hw.prev_count); + barrier(); + val = read_pmc(event->hw.idx); + delta = check_and_compute_delta(prev, val); + if (!delta) + return; + } while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev); + + local64_add(delta, &event->count); + + /* + * A number of places program the PMC with (0x80000000 - period_left). + * We never want period_left to be less than 1 because we will program + * the PMC with a value >= 0x800000000 and an edge detected PMC will + * roll around to 0 before taking an exception. We have seen this + * on POWER8. + * + * To fix this, clamp the minimum value of period_left to 1. + */ + do { + prev = local64_read(&event->hw.period_left); + val = prev - delta; + if (val < 1) + val = 1; + } while (local64_cmpxchg(&event->hw.period_left, prev, val) != prev); +} + +/* + * On some machines, PMC5 and PMC6 can't be written, don't respect + * the freeze conditions, and don't generate interrupts. This tells + * us if `event' is using such a PMC. + */ +static int is_limited_pmc(int pmcnum) +{ + return (ppmu->flags & PPMU_LIMITED_PMC5_6) + && (pmcnum == 5 || pmcnum == 6); +} + +static void freeze_limited_counters(struct cpu_hw_events *cpuhw, + unsigned long pmc5, unsigned long pmc6) +{ + struct perf_event *event; + u64 val, prev, delta; + int i; + + for (i = 0; i < cpuhw->n_limited; ++i) { + event = cpuhw->limited_counter[i]; + if (!event->hw.idx) + continue; + val = (event->hw.idx == 5) ? pmc5 : pmc6; + prev = local64_read(&event->hw.prev_count); + event->hw.idx = 0; + delta = check_and_compute_delta(prev, val); + if (delta) + local64_add(delta, &event->count); + } +} + +static void thaw_limited_counters(struct cpu_hw_events *cpuhw, + unsigned long pmc5, unsigned long pmc6) +{ + struct perf_event *event; + u64 val, prev; + int i; + + for (i = 0; i < cpuhw->n_limited; ++i) { + event = cpuhw->limited_counter[i]; + event->hw.idx = cpuhw->limited_hwidx[i]; + val = (event->hw.idx == 5) ? pmc5 : pmc6; + prev = local64_read(&event->hw.prev_count); + if (check_and_compute_delta(prev, val)) + local64_set(&event->hw.prev_count, val); + perf_event_update_userpage(event); + } +} + +/* + * Since limited events don't respect the freeze conditions, we + * have to read them immediately after freezing or unfreezing the + * other events. We try to keep the values from the limited + * events as consistent as possible by keeping the delay (in + * cycles and instructions) between freezing/unfreezing and reading + * the limited events as small and consistent as possible. + * Therefore, if any limited events are in use, we read them + * both, and always in the same order, to minimize variability, + * and do it inside the same asm that writes MMCR0. + */ +static void write_mmcr0(struct cpu_hw_events *cpuhw, unsigned long mmcr0) +{ + unsigned long pmc5, pmc6; + + if (!cpuhw->n_limited) { + mtspr(SPRN_MMCR0, mmcr0); + return; + } + + /* + * Write MMCR0, then read PMC5 and PMC6 immediately. + * To ensure we don't get a performance monitor interrupt + * between writing MMCR0 and freezing/thawing the limited + * events, we first write MMCR0 with the event overflow + * interrupt enable bits turned off. + */ + asm volatile("mtspr %3,%2; mfspr %0,%4; mfspr %1,%5" + : "=&r" (pmc5), "=&r" (pmc6) + : "r" (mmcr0 & ~(MMCR0_PMC1CE | MMCR0_PMCjCE)), + "i" (SPRN_MMCR0), + "i" (SPRN_PMC5), "i" (SPRN_PMC6)); + + if (mmcr0 & MMCR0_FC) + freeze_limited_counters(cpuhw, pmc5, pmc6); + else + thaw_limited_counters(cpuhw, pmc5, pmc6); + + /* + * Write the full MMCR0 including the event overflow interrupt + * enable bits, if necessary. + */ + if (mmcr0 & (MMCR0_PMC1CE | MMCR0_PMCjCE)) + mtspr(SPRN_MMCR0, mmcr0); +} + +/* + * Disable all events to prevent PMU interrupts and to allow + * events to be added or removed. + */ +static void power_pmu_disable(struct pmu *pmu) +{ + struct cpu_hw_events *cpuhw; + unsigned long flags, mmcr0, val; + + if (!ppmu) + return; + local_irq_save(flags); + cpuhw = this_cpu_ptr(&cpu_hw_events); + + if (!cpuhw->disabled) { + /* + * Check if we ever enabled the PMU on this cpu. + */ + if (!cpuhw->pmcs_enabled) { + ppc_enable_pmcs(); + cpuhw->pmcs_enabled = 1; + } + + /* + * Set the 'freeze counters' bit, clear EBE/BHRBA/PMCC/PMAO/FC56 + */ + val = mmcr0 = mfspr(SPRN_MMCR0); + val |= MMCR0_FC; + val &= ~(MMCR0_EBE | MMCR0_BHRBA | MMCR0_PMCC | MMCR0_PMAO | + MMCR0_FC56); + + /* + * The barrier is to make sure the mtspr has been + * executed and the PMU has frozen the events etc. + * before we return. + */ + write_mmcr0(cpuhw, val); + mb(); + isync(); + + /* + * Disable instruction sampling if it was enabled + */ + if (cpuhw->mmcr[2] & MMCRA_SAMPLE_ENABLE) { + mtspr(SPRN_MMCRA, + cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); + mb(); + isync(); + } + + cpuhw->disabled = 1; + cpuhw->n_added = 0; + + ebb_switch_out(mmcr0); + +#ifdef CONFIG_PPC64 + /* + * These are readable by userspace, may contain kernel + * addresses and are not switched by context switch, so clear + * them now to avoid leaking anything to userspace in general + * including to another process. + */ + if (ppmu->flags & PPMU_ARCH_207S) { + mtspr(SPRN_SDAR, 0); + mtspr(SPRN_SIAR, 0); + } +#endif + } + + local_irq_restore(flags); +} + +/* + * Re-enable all events if disable == 0. + * If we were previously disabled and events were added, then + * put the new config on the PMU. + */ +static void power_pmu_enable(struct pmu *pmu) +{ + struct perf_event *event; + struct cpu_hw_events *cpuhw; + unsigned long flags; + long i; + unsigned long val, mmcr0; + s64 left; + unsigned int hwc_index[MAX_HWEVENTS]; + int n_lim; + int idx; + bool ebb; + + if (!ppmu) + return; + local_irq_save(flags); + + cpuhw = this_cpu_ptr(&cpu_hw_events); + if (!cpuhw->disabled) + goto out; + + if (cpuhw->n_events == 0) { + ppc_set_pmu_inuse(0); + goto out; + } + + cpuhw->disabled = 0; + + /* + * EBB requires an exclusive group and all events must have the EBB + * flag set, or not set, so we can just check a single event. Also we + * know we have at least one event. + */ + ebb = is_ebb_event(cpuhw->event[0]); + + /* + * If we didn't change anything, or only removed events, + * no need to recalculate MMCR* settings and reset the PMCs. + * Just reenable the PMU with the current MMCR* settings + * (possibly updated for removal of events). + */ + if (!cpuhw->n_added) { + mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); + mtspr(SPRN_MMCR1, cpuhw->mmcr[1]); + goto out_enable; + } + + /* + * Clear all MMCR settings and recompute them for the new set of events. + */ + memset(cpuhw->mmcr, 0, sizeof(cpuhw->mmcr)); + + if (ppmu->compute_mmcr(cpuhw->events, cpuhw->n_events, hwc_index, + cpuhw->mmcr, cpuhw->event)) { + /* shouldn't ever get here */ + printk(KERN_ERR "oops compute_mmcr failed\n"); + goto out; + } + + if (!(ppmu->flags & PPMU_ARCH_207S)) { + /* + * Add in MMCR0 freeze bits corresponding to the attr.exclude_* + * bits for the first event. We have already checked that all + * events have the same value for these bits as the first event. + */ + event = cpuhw->event[0]; + if (event->attr.exclude_user) + cpuhw->mmcr[0] |= MMCR0_FCP; + if (event->attr.exclude_kernel) + cpuhw->mmcr[0] |= freeze_events_kernel; + if (event->attr.exclude_hv) + cpuhw->mmcr[0] |= MMCR0_FCHV; + } + + /* + * Write the new configuration to MMCR* with the freeze + * bit set and set the hardware events to their initial values. + * Then unfreeze the events. + */ + ppc_set_pmu_inuse(1); + mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); + mtspr(SPRN_MMCR1, cpuhw->mmcr[1]); + mtspr(SPRN_MMCR0, (cpuhw->mmcr[0] & ~(MMCR0_PMC1CE | MMCR0_PMCjCE)) + | MMCR0_FC); + if (ppmu->flags & PPMU_ARCH_207S) + mtspr(SPRN_MMCR2, cpuhw->mmcr[3]); + + /* + * Read off any pre-existing events that need to move + * to another PMC. + */ + for (i = 0; i < cpuhw->n_events; ++i) { + event = cpuhw->event[i]; + if (event->hw.idx && event->hw.idx != hwc_index[i] + 1) { + power_pmu_read(event); + write_pmc(event->hw.idx, 0); + event->hw.idx = 0; + } + } + + /* + * Initialize the PMCs for all the new and moved events. + */ + cpuhw->n_limited = n_lim = 0; + for (i = 0; i < cpuhw->n_events; ++i) { + event = cpuhw->event[i]; + if (event->hw.idx) + continue; + idx = hwc_index[i] + 1; + if (is_limited_pmc(idx)) { + cpuhw->limited_counter[n_lim] = event; + cpuhw->limited_hwidx[n_lim] = idx; + ++n_lim; + continue; + } + + if (ebb) + val = local64_read(&event->hw.prev_count); + else { + val = 0; + if (event->hw.sample_period) { + left = local64_read(&event->hw.period_left); + if (left < 0x80000000L) + val = 0x80000000L - left; + } + local64_set(&event->hw.prev_count, val); + } + + event->hw.idx = idx; + if (event->hw.state & PERF_HES_STOPPED) + val = 0; + write_pmc(idx, val); + + perf_event_update_userpage(event); + } + cpuhw->n_limited = n_lim; + cpuhw->mmcr[0] |= MMCR0_PMXE | MMCR0_FCECE; + + out_enable: + pmao_restore_workaround(ebb); + + mmcr0 = ebb_switch_in(ebb, cpuhw); + + mb(); + if (cpuhw->bhrb_users) + ppmu->config_bhrb(cpuhw->bhrb_filter); + + write_mmcr0(cpuhw, mmcr0); + + /* + * Enable instruction sampling if necessary + */ + if (cpuhw->mmcr[2] & MMCRA_SAMPLE_ENABLE) { + mb(); + mtspr(SPRN_MMCRA, cpuhw->mmcr[2]); + } + + out: + + local_irq_restore(flags); +} + +static int collect_events(struct perf_event *group, int max_count, + struct perf_event *ctrs[], u64 *events, + unsigned int *flags) +{ + int n = 0; + struct perf_event *event; + + if (group->pmu->task_ctx_nr == perf_hw_context) { + if (n >= max_count) + return -1; + ctrs[n] = group; + flags[n] = group->hw.event_base; + events[n++] = group->hw.config; + } + for_each_sibling_event(event, group) { + if (event->pmu->task_ctx_nr == perf_hw_context && + event->state != PERF_EVENT_STATE_OFF) { + if (n >= max_count) + return -1; + ctrs[n] = event; + flags[n] = event->hw.event_base; + events[n++] = event->hw.config; + } + } + return n; +} + +/* + * Add an event to the PMU. + * If all events are not already frozen, then we disable and + * re-enable the PMU in order to get hw_perf_enable to do the + * actual work of reconfiguring the PMU. + */ +static int power_pmu_add(struct perf_event *event, int ef_flags) +{ + struct cpu_hw_events *cpuhw; + unsigned long flags; + int n0; + int ret = -EAGAIN; + + local_irq_save(flags); + perf_pmu_disable(event->pmu); + + /* + * Add the event to the list (if there is room) + * and check whether the total set is still feasible. + */ + cpuhw = this_cpu_ptr(&cpu_hw_events); + n0 = cpuhw->n_events; + if (n0 >= ppmu->n_counter) + goto out; + cpuhw->event[n0] = event; + cpuhw->events[n0] = event->hw.config; + cpuhw->flags[n0] = event->hw.event_base; + + /* + * This event may have been disabled/stopped in record_and_restart() + * because we exceeded the ->event_limit. If re-starting the event, + * clear the ->hw.state (STOPPED and UPTODATE flags), so the user + * notification is re-enabled. + */ + if (!(ef_flags & PERF_EF_START)) + event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE; + else + event->hw.state = 0; + + /* + * If group events scheduling transaction was started, + * skip the schedulability test here, it will be performed + * at commit time(->commit_txn) as a whole + */ + if (cpuhw->txn_flags & PERF_PMU_TXN_ADD) + goto nocheck; + + if (check_excludes(cpuhw->event, cpuhw->flags, n0, 1)) + goto out; + if (power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n0 + 1)) + goto out; + event->hw.config = cpuhw->events[n0]; + +nocheck: + ebb_event_add(event); + + ++cpuhw->n_events; + ++cpuhw->n_added; + + ret = 0; + out: + if (has_branch_stack(event)) { + power_pmu_bhrb_enable(event); + cpuhw->bhrb_filter = ppmu->bhrb_filter_map( + event->attr.branch_sample_type); + } + + perf_pmu_enable(event->pmu); + local_irq_restore(flags); + return ret; +} + +/* + * Remove an event from the PMU. + */ +static void power_pmu_del(struct perf_event *event, int ef_flags) +{ + struct cpu_hw_events *cpuhw; + long i; + unsigned long flags; + + local_irq_save(flags); + perf_pmu_disable(event->pmu); + + power_pmu_read(event); + + cpuhw = this_cpu_ptr(&cpu_hw_events); + for (i = 0; i < cpuhw->n_events; ++i) { + if (event == cpuhw->event[i]) { + while (++i < cpuhw->n_events) { + cpuhw->event[i-1] = cpuhw->event[i]; + cpuhw->events[i-1] = cpuhw->events[i]; + cpuhw->flags[i-1] = cpuhw->flags[i]; + } + --cpuhw->n_events; + ppmu->disable_pmc(event->hw.idx - 1, cpuhw->mmcr); + if (event->hw.idx) { + write_pmc(event->hw.idx, 0); + event->hw.idx = 0; + } + perf_event_update_userpage(event); + break; + } + } + for (i = 0; i < cpuhw->n_limited; ++i) + if (event == cpuhw->limited_counter[i]) + break; + if (i < cpuhw->n_limited) { + while (++i < cpuhw->n_limited) { + cpuhw->limited_counter[i-1] = cpuhw->limited_counter[i]; + cpuhw->limited_hwidx[i-1] = cpuhw->limited_hwidx[i]; + } + --cpuhw->n_limited; + } + if (cpuhw->n_events == 0) { + /* disable exceptions if no events are running */ + cpuhw->mmcr[0] &= ~(MMCR0_PMXE | MMCR0_FCECE); + } + + if (has_branch_stack(event)) + power_pmu_bhrb_disable(event); + + perf_pmu_enable(event->pmu); + local_irq_restore(flags); +} + +/* + * POWER-PMU does not support disabling individual counters, hence + * program their cycle counter to their max value and ignore the interrupts. + */ + +static void power_pmu_start(struct perf_event *event, int ef_flags) +{ + unsigned long flags; + s64 left; + unsigned long val; + + if (!event->hw.idx || !event->hw.sample_period) + return; + + if (!(event->hw.state & PERF_HES_STOPPED)) + return; + + if (ef_flags & PERF_EF_RELOAD) + WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE)); + + local_irq_save(flags); + perf_pmu_disable(event->pmu); + + event->hw.state = 0; + left = local64_read(&event->hw.period_left); + + val = 0; + if (left < 0x80000000L) + val = 0x80000000L - left; + + write_pmc(event->hw.idx, val); + + perf_event_update_userpage(event); + perf_pmu_enable(event->pmu); + local_irq_restore(flags); +} + +static void power_pmu_stop(struct perf_event *event, int ef_flags) +{ + unsigned long flags; + + if (!event->hw.idx || !event->hw.sample_period) + return; + + if (event->hw.state & PERF_HES_STOPPED) + return; + + local_irq_save(flags); + perf_pmu_disable(event->pmu); + + power_pmu_read(event); + event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; + write_pmc(event->hw.idx, 0); + + perf_event_update_userpage(event); + perf_pmu_enable(event->pmu); + local_irq_restore(flags); +} + +/* + * Start group events scheduling transaction + * Set the flag to make pmu::enable() not perform the + * schedulability test, it will be performed at commit time + * + * We only support PERF_PMU_TXN_ADD transactions. Save the + * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD + * transactions. + */ +static void power_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags) +{ + struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events); + + WARN_ON_ONCE(cpuhw->txn_flags); /* txn already in flight */ + + cpuhw->txn_flags = txn_flags; + if (txn_flags & ~PERF_PMU_TXN_ADD) + return; + + perf_pmu_disable(pmu); + cpuhw->n_txn_start = cpuhw->n_events; +} + +/* + * Stop group events scheduling transaction + * Clear the flag and pmu::enable() will perform the + * schedulability test. + */ +static void power_pmu_cancel_txn(struct pmu *pmu) +{ + struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events); + unsigned int txn_flags; + + WARN_ON_ONCE(!cpuhw->txn_flags); /* no txn in flight */ + + txn_flags = cpuhw->txn_flags; + cpuhw->txn_flags = 0; + if (txn_flags & ~PERF_PMU_TXN_ADD) + return; + + perf_pmu_enable(pmu); +} + +/* + * Commit group events scheduling transaction + * Perform the group schedulability test as a whole + * Return 0 if success + */ +static int power_pmu_commit_txn(struct pmu *pmu) +{ + struct cpu_hw_events *cpuhw; + long i, n; + + if (!ppmu) + return -EAGAIN; + + cpuhw = this_cpu_ptr(&cpu_hw_events); + WARN_ON_ONCE(!cpuhw->txn_flags); /* no txn in flight */ + + if (cpuhw->txn_flags & ~PERF_PMU_TXN_ADD) { + cpuhw->txn_flags = 0; + return 0; + } + + n = cpuhw->n_events; + if (check_excludes(cpuhw->event, cpuhw->flags, 0, n)) + return -EAGAIN; + i = power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n); + if (i < 0) + return -EAGAIN; + + for (i = cpuhw->n_txn_start; i < n; ++i) + cpuhw->event[i]->hw.config = cpuhw->events[i]; + + cpuhw->txn_flags = 0; + perf_pmu_enable(pmu); + return 0; +} + +/* + * Return 1 if we might be able to put event on a limited PMC, + * or 0 if not. + * An event can only go on a limited PMC if it counts something + * that a limited PMC can count, doesn't require interrupts, and + * doesn't exclude any processor mode. + */ +static int can_go_on_limited_pmc(struct perf_event *event, u64 ev, + unsigned int flags) +{ + int n; + u64 alt[MAX_EVENT_ALTERNATIVES]; + + if (event->attr.exclude_user + || event->attr.exclude_kernel + || event->attr.exclude_hv + || event->attr.sample_period) + return 0; + + if (ppmu->limited_pmc_event(ev)) + return 1; + + /* + * The requested event_id isn't on a limited PMC already; + * see if any alternative code goes on a limited PMC. + */ + if (!ppmu->get_alternatives) + return 0; + + flags |= PPMU_LIMITED_PMC_OK | PPMU_LIMITED_PMC_REQD; + n = ppmu->get_alternatives(ev, flags, alt); + + return n > 0; +} + +/* + * Find an alternative event_id that goes on a normal PMC, if possible, + * and return the event_id code, or 0 if there is no such alternative. + * (Note: event_id code 0 is "don't count" on all machines.) + */ +static u64 normal_pmc_alternative(u64 ev, unsigned long flags) +{ + u64 alt[MAX_EVENT_ALTERNATIVES]; + int n; + + flags &= ~(PPMU_LIMITED_PMC_OK | PPMU_LIMITED_PMC_REQD); + n = ppmu->get_alternatives(ev, flags, alt); + if (!n) + return 0; + return alt[0]; +} + +/* Number of perf_events counting hardware events */ +static atomic_t num_events; +/* Used to avoid races in calling reserve/release_pmc_hardware */ +static DEFINE_MUTEX(pmc_reserve_mutex); + +/* + * Release the PMU if this is the last perf_event. + */ +static void hw_perf_event_destroy(struct perf_event *event) +{ + if (!atomic_add_unless(&num_events, -1, 1)) { + mutex_lock(&pmc_reserve_mutex); + if (atomic_dec_return(&num_events) == 0) + release_pmc_hardware(); + mutex_unlock(&pmc_reserve_mutex); + } +} + +/* + * Translate a generic cache event_id config to a raw event_id code. + */ +static int hw_perf_cache_event(u64 config, u64 *eventp) +{ + unsigned long type, op, result; + int ev; + + if (!ppmu->cache_events) + return -EINVAL; + + /* unpack config */ + type = config & 0xff; + op = (config >> 8) & 0xff; + result = (config >> 16) & 0xff; + + if (type >= PERF_COUNT_HW_CACHE_MAX || + op >= PERF_COUNT_HW_CACHE_OP_MAX || + result >= PERF_COUNT_HW_CACHE_RESULT_MAX) + return -EINVAL; + + ev = (*ppmu->cache_events)[type][op][result]; + if (ev == 0) + return -EOPNOTSUPP; + if (ev == -1) + return -EINVAL; + *eventp = ev; + return 0; +} + +static bool is_event_blacklisted(u64 ev) +{ + int i; + + for (i=0; i < ppmu->n_blacklist_ev; i++) { + if (ppmu->blacklist_ev[i] == ev) + return true; + } + + return false; +} + +static int power_pmu_event_init(struct perf_event *event) +{ + u64 ev; + unsigned long flags; + struct perf_event *ctrs[MAX_HWEVENTS]; + u64 events[MAX_HWEVENTS]; + unsigned int cflags[MAX_HWEVENTS]; + int n; + int err; + struct cpu_hw_events *cpuhw; + u64 bhrb_filter; + + if (!ppmu) + return -ENOENT; + + if (has_branch_stack(event)) { + /* PMU has BHRB enabled */ + if (!(ppmu->flags & PPMU_ARCH_207S)) + return -EOPNOTSUPP; + } + + switch (event->attr.type) { + case PERF_TYPE_HARDWARE: + ev = event->attr.config; + if (ev >= ppmu->n_generic || ppmu->generic_events[ev] == 0) + return -EOPNOTSUPP; + + if (ppmu->blacklist_ev && is_event_blacklisted(ev)) + return -EINVAL; + ev = ppmu->generic_events[ev]; + break; + case PERF_TYPE_HW_CACHE: + err = hw_perf_cache_event(event->attr.config, &ev); + if (err) + return err; + + if (ppmu->blacklist_ev && is_event_blacklisted(ev)) + return -EINVAL; + break; + case PERF_TYPE_RAW: + ev = event->attr.config; + + if (ppmu->blacklist_ev && is_event_blacklisted(ev)) + return -EINVAL; + break; + default: + return -ENOENT; + } + + event->hw.config_base = ev; + event->hw.idx = 0; + + /* + * If we are not running on a hypervisor, force the + * exclude_hv bit to 0 so that we don't care what + * the user set it to. + */ + if (!firmware_has_feature(FW_FEATURE_LPAR)) + event->attr.exclude_hv = 0; + + /* + * If this is a per-task event, then we can use + * PM_RUN_* events interchangeably with their non RUN_* + * equivalents, e.g. PM_RUN_CYC instead of PM_CYC. + * XXX we should check if the task is an idle task. + */ + flags = 0; + if (event->attach_state & PERF_ATTACH_TASK) + flags |= PPMU_ONLY_COUNT_RUN; + + /* + * If this machine has limited events, check whether this + * event_id could go on a limited event. + */ + if (ppmu->flags & PPMU_LIMITED_PMC5_6) { + if (can_go_on_limited_pmc(event, ev, flags)) { + flags |= PPMU_LIMITED_PMC_OK; + } else if (ppmu->limited_pmc_event(ev)) { + /* + * The requested event_id is on a limited PMC, + * but we can't use a limited PMC; see if any + * alternative goes on a normal PMC. + */ + ev = normal_pmc_alternative(ev, flags); + if (!ev) + return -EINVAL; + } + } + + /* Extra checks for EBB */ + err = ebb_event_check(event); + if (err) + return err; + + /* + * If this is in a group, check if it can go on with all the + * other hardware events in the group. We assume the event + * hasn't been linked into its leader's sibling list at this point. + */ + n = 0; + if (event->group_leader != event) { + n = collect_events(event->group_leader, ppmu->n_counter - 1, + ctrs, events, cflags); + if (n < 0) + return -EINVAL; + } + events[n] = ev; + ctrs[n] = event; + cflags[n] = flags; + if (check_excludes(ctrs, cflags, n, 1)) + return -EINVAL; + + cpuhw = &get_cpu_var(cpu_hw_events); + err = power_check_constraints(cpuhw, events, cflags, n + 1); + + if (has_branch_stack(event)) { + bhrb_filter = ppmu->bhrb_filter_map( + event->attr.branch_sample_type); + + if (bhrb_filter == -1) { + put_cpu_var(cpu_hw_events); + return -EOPNOTSUPP; + } + cpuhw->bhrb_filter = bhrb_filter; + } + + put_cpu_var(cpu_hw_events); + if (err) + return -EINVAL; + + event->hw.config = events[n]; + event->hw.event_base = cflags[n]; + event->hw.last_period = event->hw.sample_period; + local64_set(&event->hw.period_left, event->hw.last_period); + + /* + * For EBB events we just context switch the PMC value, we don't do any + * of the sample_period logic. We use hw.prev_count for this. + */ + if (is_ebb_event(event)) + local64_set(&event->hw.prev_count, 0); + + /* + * See if we need to reserve the PMU. + * If no events are currently in use, then we have to take a + * mutex to ensure that we don't race with another task doing + * reserve_pmc_hardware or release_pmc_hardware. + */ + err = 0; + if (!atomic_inc_not_zero(&num_events)) { + mutex_lock(&pmc_reserve_mutex); + if (atomic_read(&num_events) == 0 && + reserve_pmc_hardware(perf_event_interrupt)) + err = -EBUSY; + else + atomic_inc(&num_events); + mutex_unlock(&pmc_reserve_mutex); + } + event->destroy = hw_perf_event_destroy; + + return err; +} + +static int power_pmu_event_idx(struct perf_event *event) +{ + return event->hw.idx; +} + +ssize_t power_events_sysfs_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + struct perf_pmu_events_attr *pmu_attr; + + pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr); + + return sprintf(page, "event=0x%02llx\n", pmu_attr->id); +} + +static struct pmu power_pmu = { + .pmu_enable = power_pmu_enable, + .pmu_disable = power_pmu_disable, + .event_init = power_pmu_event_init, + .add = power_pmu_add, + .del = power_pmu_del, + .start = power_pmu_start, + .stop = power_pmu_stop, + .read = power_pmu_read, + .start_txn = power_pmu_start_txn, + .cancel_txn = power_pmu_cancel_txn, + .commit_txn = power_pmu_commit_txn, + .event_idx = power_pmu_event_idx, + .sched_task = power_pmu_sched_task, +}; + +/* + * A counter has overflowed; update its count and record + * things if requested. Note that interrupts are hard-disabled + * here so there is no possibility of being interrupted. + */ +static void record_and_restart(struct perf_event *event, unsigned long val, + struct pt_regs *regs) +{ + u64 period = event->hw.sample_period; + s64 prev, delta, left; + int record = 0; + + if (event->hw.state & PERF_HES_STOPPED) { + write_pmc(event->hw.idx, 0); + return; + } + + /* we don't have to worry about interrupts here */ + prev = local64_read(&event->hw.prev_count); + delta = check_and_compute_delta(prev, val); + local64_add(delta, &event->count); + + /* + * See if the total period for this event has expired, + * and update for the next period. + */ + val = 0; + left = local64_read(&event->hw.period_left) - delta; + if (delta == 0) + left++; + if (period) { + if (left <= 0) { + left += period; + if (left <= 0) + left = period; + + /* + * If address is not requested in the sample via + * PERF_SAMPLE_IP, just record that sample irrespective + * of SIAR valid check. + */ + if (event->attr.sample_type & PERF_SAMPLE_IP) + record = siar_valid(regs); + else + record = 1; + + event->hw.last_period = event->hw.sample_period; + } + if (left < 0x80000000LL) + val = 0x80000000LL - left; + } + + write_pmc(event->hw.idx, val); + local64_set(&event->hw.prev_count, val); + local64_set(&event->hw.period_left, left); + perf_event_update_userpage(event); + + /* + * Due to hardware limitation, sometimes SIAR could sample a kernel + * address even when freeze on supervisor state (kernel) is set in + * MMCR2. Check attr.exclude_kernel and address to drop the sample in + * these cases. + */ + if (event->attr.exclude_kernel && + (event->attr.sample_type & PERF_SAMPLE_IP) && + is_kernel_addr(mfspr(SPRN_SIAR))) + record = 0; + + /* + * Finally record data if requested. + */ + if (record) { + struct perf_sample_data data; + + perf_sample_data_init(&data, ~0ULL, event->hw.last_period); + + if (event->attr.sample_type & + (PERF_SAMPLE_ADDR | PERF_SAMPLE_PHYS_ADDR)) + perf_get_data_addr(regs, &data.addr); + + if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) { + struct cpu_hw_events *cpuhw; + cpuhw = this_cpu_ptr(&cpu_hw_events); + power_pmu_bhrb_read(cpuhw); + data.br_stack = &cpuhw->bhrb_stack; + } + + if (event->attr.sample_type & PERF_SAMPLE_DATA_SRC && + ppmu->get_mem_data_src) + ppmu->get_mem_data_src(&data.data_src, ppmu->flags, regs); + + if (event->attr.sample_type & PERF_SAMPLE_WEIGHT && + ppmu->get_mem_weight) + ppmu->get_mem_weight(&data.weight); + + if (perf_event_overflow(event, &data, regs)) + power_pmu_stop(event, 0); + } else if (period) { + /* Account for interrupt in case of invalid SIAR */ + if (perf_event_account_interrupt(event)) + power_pmu_stop(event, 0); + } +} + +/* + * Called from generic code to get the misc flags (i.e. processor mode) + * for an event_id. + */ +unsigned long perf_misc_flags(struct pt_regs *regs) +{ + u32 flags = perf_get_misc_flags(regs); + + if (flags) + return flags; + return user_mode(regs) ? PERF_RECORD_MISC_USER : + PERF_RECORD_MISC_KERNEL; +} + +/* + * Called from generic code to get the instruction pointer + * for an event_id. + */ +unsigned long perf_instruction_pointer(struct pt_regs *regs) +{ + bool use_siar = regs_use_siar(regs); + + if (use_siar && siar_valid(regs)) + return mfspr(SPRN_SIAR) + perf_ip_adjust(regs); + else if (use_siar) + return 0; // no valid instruction pointer + else + return regs->nip; +} + +static bool pmc_overflow_power7(unsigned long val) +{ + /* + * Events on POWER7 can roll back if a speculative event doesn't + * eventually complete. Unfortunately in some rare cases they will + * raise a performance monitor exception. We need to catch this to + * ensure we reset the PMC. In all cases the PMC will be 256 or less + * cycles from overflow. + * + * We only do this if the first pass fails to find any overflowing + * PMCs because a user might set a period of less than 256 and we + * don't want to mistakenly reset them. + */ + if ((0x80000000 - val) <= 256) + return true; + + return false; +} + +static bool pmc_overflow(unsigned long val) +{ + if ((int)val < 0) + return true; + + return false; +} + +/* + * Performance monitor interrupt stuff + */ +static void perf_event_interrupt(struct pt_regs *regs) +{ + int i, j; + struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events); + struct perf_event *event; + unsigned long val[8]; + int found, active; + int nmi; + + if (cpuhw->n_limited) + freeze_limited_counters(cpuhw, mfspr(SPRN_PMC5), + mfspr(SPRN_PMC6)); + + perf_read_regs(regs); + + nmi = perf_intr_is_nmi(regs); + if (nmi) + nmi_enter(); + else + irq_enter(); + + /* Read all the PMCs since we'll need them a bunch of times */ + for (i = 0; i < ppmu->n_counter; ++i) + val[i] = read_pmc(i + 1); + + /* Try to find what caused the IRQ */ + found = 0; + for (i = 0; i < ppmu->n_counter; ++i) { + if (!pmc_overflow(val[i])) + continue; + if (is_limited_pmc(i + 1)) + continue; /* these won't generate IRQs */ + /* + * We've found one that's overflowed. For active + * counters we need to log this. For inactive + * counters, we need to reset it anyway + */ + found = 1; + active = 0; + for (j = 0; j < cpuhw->n_events; ++j) { + event = cpuhw->event[j]; + if (event->hw.idx == (i + 1)) { + active = 1; + record_and_restart(event, val[i], regs); + break; + } + } + if (!active) + /* reset non active counters that have overflowed */ + write_pmc(i + 1, 0); + } + if (!found && pvr_version_is(PVR_POWER7)) { + /* check active counters for special buggy p7 overflow */ + for (i = 0; i < cpuhw->n_events; ++i) { + event = cpuhw->event[i]; + if (!event->hw.idx || is_limited_pmc(event->hw.idx)) + continue; + if (pmc_overflow_power7(val[event->hw.idx - 1])) { + /* event has overflowed in a buggy way*/ + found = 1; + record_and_restart(event, + val[event->hw.idx - 1], + regs); + } + } + } + if (!found && !nmi && printk_ratelimit()) + printk(KERN_WARNING "Can't find PMC that caused IRQ\n"); + + /* + * Reset MMCR0 to its normal value. This will set PMXE and + * clear FC (freeze counters) and PMAO (perf mon alert occurred) + * and thus allow interrupts to occur again. + * XXX might want to use MSR.PM to keep the events frozen until + * we get back out of this interrupt. + */ + write_mmcr0(cpuhw, cpuhw->mmcr[0]); + + if (nmi) + nmi_exit(); + else + irq_exit(); +} + +static int power_pmu_prepare_cpu(unsigned int cpu) +{ + struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu); + + if (ppmu) { + memset(cpuhw, 0, sizeof(*cpuhw)); + cpuhw->mmcr[0] = MMCR0_FC; + } + return 0; +} + +int register_power_pmu(struct power_pmu *pmu) +{ + if (ppmu) + return -EBUSY; /* something's already registered */ + + ppmu = pmu; + pr_info("%s performance monitor hardware support registered\n", + pmu->name); + + power_pmu.attr_groups = ppmu->attr_groups; + +#ifdef MSR_HV + /* + * Use FCHV to ignore kernel events if MSR.HV is set. + */ + if (mfmsr() & MSR_HV) + freeze_events_kernel = MMCR0_FCHV; +#endif /* CONFIG_PPC64 */ + + perf_pmu_register(&power_pmu, "cpu", PERF_TYPE_RAW); + cpuhp_setup_state(CPUHP_PERF_POWER, "perf/powerpc:prepare", + power_pmu_prepare_cpu, NULL); + return 0; +} |