| /* |
| * 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]; |
| unsigned long mmcr[3]; |
| 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 group_flag; |
| int n_txn_start; |
| |
| /* BHRB bits */ |
| u64 bhrb_filter; /* BHRB HW branch filter */ |
| int bhrb_users; |
| void *bhrb_context; |
| struct perf_branch_stack bhrb_stack; |
| struct perf_branch_entry bhrb_entries[BHRB_MAX_ENTRIES]; |
| }; |
| |
| DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); |
| |
| 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_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, unsigned long mmcr0) |
| { |
| return mmcr0; |
| } |
| |
| static inline void power_pmu_bhrb_enable(struct perf_event *event) {} |
| static inline void power_pmu_bhrb_disable(struct perf_event *event) {} |
| void power_pmu_flush_branch_stack(void) {} |
| static inline void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) {} |
| #endif /* CONFIG_PPC32 */ |
| |
| static bool regs_use_siar(struct pt_regs *regs) |
| { |
| return !!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 |
| sdsync = MMCRA_SDSYNC; |
| |
| sdar_valid = mmcra & sdsync; |
| } |
| |
| if (!(mmcra & MMCRA_SAMPLE_ENABLE) || sdar_valid) |
| *addrp = mfspr(SPRN_SDAR); |
| } |
| |
| 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 (siar >= PAGE_OFFSET) |
| 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 (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; |
| } |
| |
| /* |
| * 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 = &__get_cpu_var(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++; |
| } |
| |
| static void power_pmu_bhrb_disable(struct perf_event *event) |
| { |
| struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); |
| |
| if (!ppmu->bhrb_nr) |
| return; |
| |
| cpuhw->bhrb_users--; |
| WARN_ON_ONCE(cpuhw->bhrb_users < 0); |
| |
| 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. |
| */ |
| void power_pmu_flush_branch_stack(void) |
| { |
| if (ppmu->bhrb_nr) |
| 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)) |
| return branch_target((unsigned int *)addr); |
| |
| /* 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 */ |
| 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; |
| |
| /* 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_EBB) && |
| ((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.inherit || event->attr.sample_period || |
| event->attr.enable_on_exec || event->attr.freq) |
| 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, unsigned long mmcr0) |
| { |
| if (!ebb) |
| goto out; |
| |
| /* Enable EBB and read/write to all 6 PMCs for userspace */ |
| mmcr0 |= MMCR0_EBE | MMCR0_PMCC_U6; |
| |
| /* Add any bits from the user reg, FC or PMAO */ |
| mmcr0 |= current->thread.mmcr0; |
| |
| /* Be careful not to set PMXE if userspace had it cleared */ |
| 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); |
| mtspr(SPRN_MMCR2, current->thread.mmcr2); |
| out: |
| return mmcr0; |
| } |
| #endif /* CONFIG_PPC64 */ |
| |
| static void perf_event_interrupt(struct pt_regs *regs); |
| |
| void perf_event_print_debug(void) |
| { |
| } |
| |
| /* |
| * 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); |
| } |
| } |
| |
| /* |
| * 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; |
| |
| 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 dectect 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); |
| local64_sub(delta, &event->hw.period_left); |
| } |
| |
| /* |
| * 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 = &__get_cpu_var(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/PMCC/PMAO/FC56. |
| */ |
| val = mmcr0 = mfspr(SPRN_MMCR0); |
| val |= MMCR0_FC; |
| val &= ~(MMCR0_EBE | 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(); |
| |
| /* |
| * Disable instruction sampling if it was enabled |
| */ |
| if (cpuhw->mmcr[2] & MMCRA_SAMPLE_ENABLE) { |
| mtspr(SPRN_MMCRA, |
| cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); |
| mb(); |
| } |
| |
| cpuhw->disabled = 1; |
| cpuhw->n_added = 0; |
| |
| ebb_switch_out(mmcr0); |
| } |
| |
| 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 = &__get_cpu_var(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; |
| } |
| |
| /* |
| * Compute MMCR* values for the new set of events |
| */ |
| if (ppmu->compute_mmcr(cpuhw->events, cpuhw->n_events, hwc_index, |
| cpuhw->mmcr)) { |
| /* shouldn't ever get here */ |
| printk(KERN_ERR "oops compute_mmcr failed\n"); |
| goto out; |
| } |
| |
| /* |
| * 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 values 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); |
| |
| /* |
| * 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: |
| mmcr0 = ebb_switch_in(ebb, cpuhw->mmcr[0]); |
| |
| 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 (!is_software_event(group)) { |
| if (n >= max_count) |
| return -1; |
| ctrs[n] = group; |
| flags[n] = group->hw.event_base; |
| events[n++] = group->hw.config; |
| } |
| list_for_each_entry(event, &group->sibling_list, group_entry) { |
| if (!is_software_event(event) && |
| 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 a 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 = &__get_cpu_var(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->group_flag & PERF_EVENT_TXN) |
| 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 a 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 = &__get_cpu_var(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 |
| */ |
| void power_pmu_start_txn(struct pmu *pmu) |
| { |
| struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); |
| |
| perf_pmu_disable(pmu); |
| cpuhw->group_flag |= PERF_EVENT_TXN; |
| cpuhw->n_txn_start = cpuhw->n_events; |
| } |
| |
| /* |
| * Stop group events scheduling transaction |
| * Clear the flag and pmu::enable() will perform the |
| * schedulability test. |
| */ |
| void power_pmu_cancel_txn(struct pmu *pmu) |
| { |
| struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); |
| |
| cpuhw->group_flag &= ~PERF_EVENT_TXN; |
| perf_pmu_enable(pmu); |
| } |
| |
| /* |
| * Commit group events scheduling transaction |
| * Perform the group schedulability test as a whole |
| * Return 0 if success |
| */ |
| int power_pmu_commit_txn(struct pmu *pmu) |
| { |
| struct cpu_hw_events *cpuhw; |
| long i, n; |
| |
| if (!ppmu) |
| return -EAGAIN; |
| cpuhw = &__get_cpu_var(cpu_hw_events); |
| 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->group_flag &= ~PERF_EVENT_TXN; |
| perf_pmu_enable(pmu); |
| return 0; |
| } |
| |
| /* |
| * Return 1 if we might be able to put event on a limited PMC, |
| * or 0 if not. |
| * A 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 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; |
| |
| if (!ppmu) |
| return -ENOENT; |
| |
| if (has_branch_stack(event)) { |
| /* PMU has BHRB enabled */ |
| if (!(ppmu->flags & PPMU_BHRB)) |
| 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; |
| ev = ppmu->generic_events[ev]; |
| break; |
| case PERF_TYPE_HW_CACHE: |
| err = hw_perf_cache_event(event->attr.config, &ev); |
| if (err) |
| return err; |
| break; |
| case PERF_TYPE_RAW: |
| ev = event->attr.config; |
| 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)) { |
| cpuhw->bhrb_filter = ppmu->bhrb_filter_map( |
| event->attr.branch_sample_type); |
| |
| if(cpuhw->bhrb_filter == -1) |
| return -EOPNOTSUPP; |
| } |
| |
| 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); |
| } |
| |
| 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, |
| .flush_branch_stack = power_pmu_flush_branch_stack, |
| }; |
| |
| /* |
| * 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; |
| record = siar_valid(regs); |
| 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); |
| |
| /* |
| * 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_get_data_addr(regs, &data.addr); |
| |
| if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) { |
| struct cpu_hw_events *cpuhw; |
| cpuhw = &__get_cpu_var(cpu_hw_events); |
| power_pmu_bhrb_read(cpuhw); |
| data.br_stack = &cpuhw->bhrb_stack; |
| } |
| |
| if (perf_event_overflow(event, &data, regs)) |
| 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 = &__get_cpu_var(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 void power_pmu_setup(int cpu) |
| { |
| struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu); |
| |
| if (!ppmu) |
| return; |
| memset(cpuhw, 0, sizeof(*cpuhw)); |
| cpuhw->mmcr[0] = MMCR0_FC; |
| } |
| |
| static int |
| power_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) |
| { |
| unsigned int cpu = (long)hcpu; |
| |
| switch (action & ~CPU_TASKS_FROZEN) { |
| case CPU_UP_PREPARE: |
| power_pmu_setup(cpu); |
| break; |
| |
| default: |
| break; |
| } |
| |
| return NOTIFY_OK; |
| } |
| |
| 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); |
| perf_cpu_notifier(power_pmu_notifier); |
| |
| return 0; |
| } |