diff options
Diffstat (limited to 'arch/powerpc/perf/core-book3s.c')
-rw-r--r-- | arch/powerpc/perf/core-book3s.c | 280 |
1 files changed, 159 insertions, 121 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index c627843c5b2e..426180b84978 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -13,11 +13,13 @@ #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 @@ -100,6 +102,10 @@ static inline int siar_valid(struct pt_regs *regs) return 1; } +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) @@ -308,6 +314,159 @@ static inline int siar_valid(struct pt_regs *regs) 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; +} + #endif /* CONFIG_PPC64 */ static void perf_event_interrupt(struct pt_regs *regs); @@ -904,47 +1063,6 @@ static int collect_events(struct perf_event *group, int max_count, return n; } -/* Reset all possible BHRB entries */ -static void power_pmu_bhrb_reset(void) -{ - asm volatile(PPC_CLRBHRB); -} - -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++; -} - -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; - } -} - /* * Add a event to the PMU. * If all events are not already frozen, then we disable and @@ -1180,15 +1298,6 @@ int power_pmu_commit_txn(struct pmu *pmu) return 0; } -/* 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(); -} - /* * Return 1 if we might be able to put event on a limited PMC, * or 0 if not. @@ -1458,77 +1567,6 @@ struct pmu power_pmu = { .flush_branch_stack = power_pmu_flush_branch_stack, }; -/* Processing BHRB entries */ -void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) -{ - u64 val; - u64 addr; - int r_index, u_index, target, pred; - - r_index = 0; - u_index = 0; - while (r_index < ppmu->bhrb_nr) { - /* Assembly read function */ - val = read_bhrb(r_index); - - /* Terminal marker: End of valid BHRB entries */ - if (val == 0) { - break; - } else { - /* BHRB field break up */ - addr = val & BHRB_EA; - pred = val & BHRB_PREDICTION; - target = val & BHRB_TARGET; - - /* Probable Missed entry: Not applicable for POWER8 */ - if ((addr == 0) && (target == 0) && (pred == 1)) { - r_index++; - continue; - } - - /* Real Missed entry: Power8 based missed entry */ - if ((addr == 0) && (target == 1) && (pred == 1)) { - r_index++; - continue; - } - - /* Reserved condition: Not a valid entry */ - if ((addr == 0) && (target == 1) && (pred == 0)) { - r_index++; - continue; - } - - /* Is a target address */ - if (val & BHRB_TARGET) { - /* First address cannot be a target address */ - if (r_index == 0) { - r_index++; - continue; - } - - /* Update target address for the previous entry */ - cpuhw->bhrb_entries[u_index - 1].to = addr; - cpuhw->bhrb_entries[u_index - 1].mispred = pred; - cpuhw->bhrb_entries[u_index - 1].predicted = ~pred; - - /* Dont increment u_index */ - r_index++; - } else { - /* Update address, flags for current entry */ - cpuhw->bhrb_entries[u_index].from = addr; - cpuhw->bhrb_entries[u_index].mispred = pred; - cpuhw->bhrb_entries[u_index].predicted = ~pred; - - /* Successfully popullated one entry */ - u_index++; - r_index++; - } - } - } - cpuhw->bhrb_stack.nr = u_index; - return; -} - /* * A counter has overflowed; update its count and record * things if requested. Note that interrupts are hard-disabled |