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Diffstat (limited to 'arch/powerpc/perf/core-book3s.c')
-rw-r--r--arch/powerpc/perf/core-book3s.c280
1 files changed, 159 insertions, 121 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index c627843c5b2..426180b8497 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
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-04 14:38:59 +0000