1 files changed, 83 insertions, 108 deletions

diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 20185ea64aa6..1559fb0b9296 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -46,23 +46,26 @@
 #include <linux/smp.h>
 
 #include <linux/hw_breakpoint.h>
-
-
 /*
  * Constraints data
  */
+struct bp_cpuinfo {
+	/* Number of pinned cpu breakpoints in a cpu */
+	unsigned int	cpu_pinned;
+	/* tsk_pinned[n] is the number of tasks having n+1 breakpoints */
+	unsigned int	*tsk_pinned;
+	/* Number of non-pinned cpu/task breakpoints in a cpu */
+	unsigned int	flexible; /* XXX: placeholder, see fetch_this_slot() */
+};
 
-/* Number of pinned cpu breakpoints in a cpu */
-static DEFINE_PER_CPU(unsigned int, nr_cpu_bp_pinned[TYPE_MAX]);
-
-/* Number of pinned task breakpoints in a cpu */
-static DEFINE_PER_CPU(unsigned int *, nr_task_bp_pinned[TYPE_MAX]);
-
-/* Number of non-pinned cpu/task breakpoints in a cpu */
-static DEFINE_PER_CPU(unsigned int, nr_bp_flexible[TYPE_MAX]);
-
+static DEFINE_PER_CPU(struct bp_cpuinfo, bp_cpuinfo[TYPE_MAX]);
 static int nr_slots[TYPE_MAX];
 
+static struct bp_cpuinfo *get_bp_info(int cpu, enum bp_type_idx type)
+{
+	return per_cpu_ptr(bp_cpuinfo + type, cpu);
+}
+
 /* Keep track of the breakpoints attached to tasks */
 static LIST_HEAD(bp_task_head);
 
@@ -96,8 +99,8 @@ static inline enum bp_type_idx find_slot_idx(struct perf_event *bp)
  */
 static unsigned int max_task_bp_pinned(int cpu, enum bp_type_idx type)
 {
+	unsigned int *tsk_pinned = get_bp_info(cpu, type)->tsk_pinned;
 	int i;
-	unsigned int *tsk_pinned = per_cpu(nr_task_bp_pinned[type], cpu);
 
 	for (i = nr_slots[type] - 1; i >= 0; i--) {
 		if (tsk_pinned[i] > 0)
@@ -127,6 +130,13 @@ static int task_bp_pinned(int cpu, struct perf_event *bp, enum bp_type_idx type)
 	return count;
 }
 
+static const struct cpumask *cpumask_of_bp(struct perf_event *bp)
+{
+	if (bp->cpu >= 0)
+		return cpumask_of(bp->cpu);
+	return cpu_possible_mask;
+}
+
 /*
  * Report the number of pinned/un-pinned breakpoints we have in
  * a given cpu (cpu > -1) or in all of them (cpu = -1).
@@ -135,25 +145,15 @@ static void
 fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp,
 		    enum bp_type_idx type)
 {
-	int cpu = bp->cpu;
-	struct task_struct *tsk = bp->hw.bp_target;
-
-	if (cpu >= 0) {
-		slots->pinned = per_cpu(nr_cpu_bp_pinned[type], cpu);
-		if (!tsk)
-			slots->pinned += max_task_bp_pinned(cpu, type);
-		else
-			slots->pinned += task_bp_pinned(cpu, bp, type);
-		slots->flexible = per_cpu(nr_bp_flexible[type], cpu);
-
-		return;
-	}
+	const struct cpumask *cpumask = cpumask_of_bp(bp);
+	int cpu;
 
-	for_each_possible_cpu(cpu) {
-		unsigned int nr;
+	for_each_cpu(cpu, cpumask) {
+		struct bp_cpuinfo *info = get_bp_info(cpu, type);
+		int nr;
 
-		nr = per_cpu(nr_cpu_bp_pinned[type], cpu);
-		if (!tsk)
+		nr = info->cpu_pinned;
+		if (!bp->hw.bp_target)
 			nr += max_task_bp_pinned(cpu, type);
 		else
 			nr += task_bp_pinned(cpu, bp, type);
@@ -161,8 +161,7 @@ fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp,
 		if (nr > slots->pinned)
 			slots->pinned = nr;
 
-		nr = per_cpu(nr_bp_flexible[type], cpu);
-
+		nr = info->flexible;
 		if (nr > slots->flexible)
 			slots->flexible = nr;
 	}
@@ -182,29 +181,19 @@ fetch_this_slot(struct bp_busy_slots *slots, int weight)
 /*
  * Add a pinned breakpoint for the given task in our constraint table
  */
-static void toggle_bp_task_slot(struct perf_event *bp, int cpu, bool enable,
+static void toggle_bp_task_slot(struct perf_event *bp, int cpu,
 				enum bp_type_idx type, int weight)
 {
-	unsigned int *tsk_pinned;
-	int old_count = 0;
-	int old_idx = 0;
-	int idx = 0;
-
-	old_count = task_bp_pinned(cpu, bp, type);
-	old_idx = old_count - 1;
-	idx = old_idx + weight;
-
-	/* tsk_pinned[n] is the number of tasks having n breakpoints */
-	tsk_pinned = per_cpu(nr_task_bp_pinned[type], cpu);
-	if (enable) {
-		tsk_pinned[idx]++;
-		if (old_count > 0)
-			tsk_pinned[old_idx]--;
-	} else {
-		tsk_pinned[idx]--;
-		if (old_count > 0)
-			tsk_pinned[old_idx]++;
-	}
+	unsigned int *tsk_pinned = get_bp_info(cpu, type)->tsk_pinned;
+	int old_idx, new_idx;
+
+	old_idx = task_bp_pinned(cpu, bp, type) - 1;
+	new_idx = old_idx + weight;
+
+	if (old_idx >= 0)
+		tsk_pinned[old_idx]--;
+	if (new_idx >= 0)
+		tsk_pinned[new_idx]++;
 }
 
 /*
@@ -214,33 +203,26 @@ static void
 toggle_bp_slot(struct perf_event *bp, bool enable, enum bp_type_idx type,
 	       int weight)
 {
-	int cpu = bp->cpu;
-	struct task_struct *tsk = bp->hw.bp_target;
+	const struct cpumask *cpumask = cpumask_of_bp(bp);
+	int cpu;
 
-	/* Pinned counter cpu profiling */
-	if (!tsk) {
+	if (!enable)
+		weight = -weight;
 
-		if (enable)
-			per_cpu(nr_cpu_bp_pinned[type], bp->cpu) += weight;
-		else
-			per_cpu(nr_cpu_bp_pinned[type], bp->cpu) -= weight;
+	/* Pinned counter cpu profiling */
+	if (!bp->hw.bp_target) {
+		get_bp_info(bp->cpu, type)->cpu_pinned += weight;
 		return;
 	}
 
 	/* Pinned counter task profiling */
-
-	if (!enable)
-		list_del(&bp->hw.bp_list);
-
-	if (cpu >= 0) {
-		toggle_bp_task_slot(bp, cpu, enable, type, weight);
-	} else {
-		for_each_possible_cpu(cpu)
-			toggle_bp_task_slot(bp, cpu, enable, type, weight);
-	}
+	for_each_cpu(cpu, cpumask)
+		toggle_bp_task_slot(bp, cpu, type, weight);
 
 	if (enable)
 		list_add_tail(&bp->hw.bp_list, &bp_task_head);
+	else
+		list_del(&bp->hw.bp_list);
 }
 
 /*
@@ -261,8 +243,8 @@ __weak void arch_unregister_hw_breakpoint(struct perf_event *bp)
  *
  *   - If attached to a single cpu, check:
  *
- *       (per_cpu(nr_bp_flexible, cpu) || (per_cpu(nr_cpu_bp_pinned, cpu)
- *           + max(per_cpu(nr_task_bp_pinned, cpu)))) < HBP_NUM
+ *       (per_cpu(info->flexible, cpu) || (per_cpu(info->cpu_pinned, cpu)
+ *           + max(per_cpu(info->tsk_pinned, cpu)))) < HBP_NUM
  *
  *       -> If there are already non-pinned counters in this cpu, it means
  *          there is already a free slot for them.
@@ -272,8 +254,8 @@ __weak void arch_unregister_hw_breakpoint(struct perf_event *bp)
  *
  *   - If attached to every cpus, check:
  *
- *       (per_cpu(nr_bp_flexible, *) || (max(per_cpu(nr_cpu_bp_pinned, *))
- *           + max(per_cpu(nr_task_bp_pinned, *)))) < HBP_NUM
+ *       (per_cpu(info->flexible, *) || (max(per_cpu(info->cpu_pinned, *))
+ *           + max(per_cpu(info->tsk_pinned, *)))) < HBP_NUM
  *
  *       -> This is roughly the same, except we check the number of per cpu
  *          bp for every cpu and we keep the max one. Same for the per tasks
@@ -284,16 +266,16 @@ __weak void arch_unregister_hw_breakpoint(struct perf_event *bp)
  *
  *   - If attached to a single cpu, check:
  *
- *       ((per_cpu(nr_bp_flexible, cpu) > 1) + per_cpu(nr_cpu_bp_pinned, cpu)
- *            + max(per_cpu(nr_task_bp_pinned, cpu))) < HBP_NUM
+ *       ((per_cpu(info->flexible, cpu) > 1) + per_cpu(info->cpu_pinned, cpu)
+ *            + max(per_cpu(info->tsk_pinned, cpu))) < HBP_NUM
  *
- *       -> Same checks as before. But now the nr_bp_flexible, if any, must keep
+ *       -> Same checks as before. But now the info->flexible, if any, must keep
  *          one register at least (or they will never be fed).
  *
  *   - If attached to every cpus, check:
  *
- *       ((per_cpu(nr_bp_flexible, *) > 1) + max(per_cpu(nr_cpu_bp_pinned, *))
- *            + max(per_cpu(nr_task_bp_pinned, *))) < HBP_NUM
+ *       ((per_cpu(info->flexible, *) > 1) + max(per_cpu(info->cpu_pinned, *))
+ *            + max(per_cpu(info->tsk_pinned, *))) < HBP_NUM
  */
 static int __reserve_bp_slot(struct perf_event *bp)
 {
@@ -518,8 +500,8 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
 			    perf_overflow_handler_t triggered,
 			    void *context)
 {
-	struct perf_event * __percpu *cpu_events, **pevent, *bp;
-	long err;
+	struct perf_event * __percpu *cpu_events, *bp;
+	long err = 0;
 	int cpu;
 
 	cpu_events = alloc_percpu(typeof(*cpu_events));
@@ -528,31 +510,21 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
 
 	get_online_cpus();
 	for_each_online_cpu(cpu) {
-		pevent = per_cpu_ptr(cpu_events, cpu);
 		bp = perf_event_create_kernel_counter(attr, cpu, NULL,
 						      triggered, context);
-
-		*pevent = bp;
-
 		if (IS_ERR(bp)) {
 			err = PTR_ERR(bp);
-			goto fail;
+			break;
 		}
-	}
-	put_online_cpus();
 
-	return cpu_events;
-
-fail:
-	for_each_online_cpu(cpu) {
-		pevent = per_cpu_ptr(cpu_events, cpu);
-		if (IS_ERR(*pevent))
-			break;
-		unregister_hw_breakpoint(*pevent);
+		per_cpu(*cpu_events, cpu) = bp;
 	}
 	put_online_cpus();
 
-	free_percpu(cpu_events);
+	if (likely(!err))
+		return cpu_events;
+
+	unregister_wide_hw_breakpoint(cpu_events);
 	return (void __percpu __force *)ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint);
@@ -564,12 +536,10 @@ EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint);
 void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)
 {
 	int cpu;
-	struct perf_event **pevent;
 
-	for_each_possible_cpu(cpu) {
-		pevent = per_cpu_ptr(cpu_events, cpu);
-		unregister_hw_breakpoint(*pevent);
-	}
+	for_each_possible_cpu(cpu)
+		unregister_hw_breakpoint(per_cpu(*cpu_events, cpu));
+
 	free_percpu(cpu_events);
 }
 EXPORT_SYMBOL_GPL(unregister_wide_hw_breakpoint);
@@ -612,6 +582,11 @@ static int hw_breakpoint_add(struct perf_event *bp, int flags)
 	if (!(flags & PERF_EF_START))
 		bp->hw.state = PERF_HES_STOPPED;
 
+	if (is_sampling_event(bp)) {
+		bp->hw.last_period = bp->hw.sample_period;
+		perf_swevent_set_period(bp);
+	}
+
 	return arch_install_hw_breakpoint(bp);
 }
 
@@ -650,7 +625,6 @@ static struct pmu perf_breakpoint = {
 
 int __init init_hw_breakpoint(void)
 {
-	unsigned int **task_bp_pinned;
 	int cpu, err_cpu;
 	int i;
 
@@ -659,10 +633,11 @@ int __init init_hw_breakpoint(void)
 
 	for_each_possible_cpu(cpu) {
 		for (i = 0; i < TYPE_MAX; i++) {
-			task_bp_pinned = &per_cpu(nr_task_bp_pinned[i], cpu);
-			*task_bp_pinned = kzalloc(sizeof(int) * nr_slots[i],
-						  GFP_KERNEL);
-			if (!*task_bp_pinned)
+			struct bp_cpuinfo *info = get_bp_info(cpu, i);
+
+			info->tsk_pinned = kcalloc(nr_slots[i], sizeof(int),
+							GFP_KERNEL);
+			if (!info->tsk_pinned)
 				goto err_alloc;
 		}
 	}
@@ -676,7 +651,7 @@ int __init init_hw_breakpoint(void)
  err_alloc:
 	for_each_possible_cpu(err_cpu) {
 		for (i = 0; i < TYPE_MAX; i++)
-			kfree(per_cpu(nr_task_bp_pinned[i], err_cpu));
+			kfree(get_bp_info(err_cpu, i)->tsk_pinned);
 		if (err_cpu == cpu)
 			break;
 	}