[PATCH 2/7] arm-cci: Cleanup PMU driver code

From: Suzuki K. Poulose
Date: Tue May 05 2015 - 07:50:45 EST

From: "Suzuki K. Poulose" <suzuki.poulose@xxxxxxx>

This patch gets rid of the global struct cci_pmu variable and makes
the code use the cci_pmu explicitly. Makes code a bit more robust
and reader friendly.

Cc: Punit Agrawal <punit.agrawal@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@xxxxxxx>
---
drivers/bus/arm-cci.c | 142 ++++++++++++++++++++++++++++---------------------
1 file changed, 80 insertions(+), 62 deletions(-)

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index 941b831..27cc200 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -124,9 +124,9 @@ struct cci_pmu {
int num_events;
atomic_t active_events;
struct mutex reserve_mutex;
+ struct notifier_block cpu_nb;
cpumask_t cpus;
};
-static struct cci_pmu *pmu;

#define to_cci_pmu(c) (container_of(c, struct cci_pmu, pmu))

@@ -179,7 +179,7 @@ enum cci400_perf_events {
#define CCI_REV_R1_MASTER_PORT_MIN_EV 0x00
#define CCI_REV_R1_MASTER_PORT_MAX_EV 0x11

-static int pmu_validate_hw_event(unsigned long hw_event)
+static int pmu_validate_hw_event(struct cci_pmu *cci_pmu, unsigned long hw_event)
{
u8 ev_source = CCI_PMU_EVENT_SOURCE(hw_event);
u8 ev_code = CCI_PMU_EVENT_CODE(hw_event);
@@ -207,8 +207,8 @@ static int pmu_validate_hw_event(unsigned long hw_event)
return -ENOENT;
}

- if (ev_code >= pmu->model->event_ranges[if_type].min &&
- ev_code <= pmu->model->event_ranges[if_type].max)
+ if (ev_code >= cci_pmu->model->event_ranges[if_type].min &&
+ ev_code <= cci_pmu->model->event_ranges[if_type].max)
return hw_event;

return -ENOENT;
@@ -239,29 +239,31 @@ static int pmu_is_valid_counter(struct cci_pmu *cci_pmu, int idx)
idx <= CCI_PMU_CNTR_LAST(cci_pmu);
}

-static u32 pmu_read_register(int idx, unsigned int offset)
+static u32 pmu_read_register(struct cci_pmu *cci_pmu, int idx, unsigned int offset)
{
- return readl_relaxed(pmu->base + CCI_PMU_CNTR_BASE(idx) + offset);
+ return readl_relaxed(cci_pmu->base + CCI_PMU_CNTR_BASE(idx) + offset);
}

-static void pmu_write_register(u32 value, int idx, unsigned int offset)
+static void pmu_write_register(struct cci_pmu *cci_pmu, u32 value,
+ int idx, unsigned int offset)
{
- return writel_relaxed(value, pmu->base + CCI_PMU_CNTR_BASE(idx) + offset);
+ return writel_relaxed(value, cci_pmu->base +
+ CCI_PMU_CNTR_BASE(idx) + offset);
}

-static void pmu_disable_counter(int idx)
+static void pmu_disable_counter(struct cci_pmu *cci_pmu, int idx)
{
- pmu_write_register(0, idx, CCI_PMU_CNTR_CTRL);
+ pmu_write_register(cci_pmu, 0, idx, CCI_PMU_CNTR_CTRL);
}

-static void pmu_enable_counter(int idx)
+static void pmu_enable_counter(struct cci_pmu *cci_pmu, int idx)
{
- pmu_write_register(1, idx, CCI_PMU_CNTR_CTRL);
+ pmu_write_register(cci_pmu, 1, idx, CCI_PMU_CNTR_CTRL);
}

-static void pmu_set_event(int idx, unsigned long event)
+static void pmu_set_event(struct cci_pmu *cci_pmu, int idx, unsigned long event)
{
- pmu_write_register(event, idx, CCI_PMU_EVT_SEL);
+ pmu_write_register(cci_pmu, event, idx, CCI_PMU_EVT_SEL);
}

static u32 pmu_get_max_counters(void)
@@ -306,7 +308,8 @@ static int pmu_map_event(struct perf_event *event)
if (config == CCI_PMU_CYCLES)
mapping = config;
else
- mapping = pmu_validate_hw_event(config);
+ mapping = pmu_validate_hw_event(to_cci_pmu(event->pmu),
+ config);

return mapping;
}
@@ -319,7 +322,7 @@ static int pmu_request_irq(struct cci_pmu *cci_pmu, irq_handler_t handler)
if (unlikely(!pmu_device))
return -ENODEV;

- if (pmu->nr_irqs < 1) {
+ if (cci_pmu->nr_irqs < 1) {
dev_err(&pmu_device->dev, "no irqs for CCI PMUs defined\n");
return -ENODEV;
}
@@ -331,16 +334,16 @@ static int pmu_request_irq(struct cci_pmu *cci_pmu, irq_handler_t handler)
*
* This should allow handling of non-unique interrupt for the counters.
*/
- for (i = 0; i < pmu->nr_irqs; i++) {
- int err = request_irq(pmu->irqs[i], handler, IRQF_SHARED,
+ for (i = 0; i < cci_pmu->nr_irqs; i++) {
+ int err = request_irq(cci_pmu->irqs[i], handler, IRQF_SHARED,
"arm-cci-pmu", cci_pmu);
if (err) {
dev_err(&pmu_device->dev, "unable to request IRQ%d for ARM CCI PMU counters\n",
- pmu->irqs[i]);
+ cci_pmu->irqs[i]);
return err;
}

- set_bit(i, &pmu->active_irqs);
+ set_bit(i, &cci_pmu->active_irqs);
}

return 0;
@@ -350,11 +353,11 @@ static void pmu_free_irq(struct cci_pmu *cci_pmu)
{
int i;

- for (i = 0; i < pmu->nr_irqs; i++) {
- if (!test_and_clear_bit(i, &pmu->active_irqs))
+ for (i = 0; i < cci_pmu->nr_irqs; i++) {
+ if (!test_and_clear_bit(i, &cci_pmu->active_irqs))
continue;

- free_irq(pmu->irqs[i], cci_pmu);
+ free_irq(cci_pmu->irqs[i], cci_pmu);
}
}

@@ -369,7 +372,7 @@ static u32 pmu_read_counter(struct perf_event *event)
dev_err(&cci_pmu->plat_device->dev, "Invalid CCI PMU counter %d\n", idx);
return 0;
}
- value = pmu_read_register(idx, CCI_PMU_CNTR);
+ value = pmu_read_register(cci_pmu, idx, CCI_PMU_CNTR);

return value;
}
@@ -383,7 +386,7 @@ static void pmu_write_counter(struct perf_event *event, u32 value)
if (unlikely(!pmu_is_valid_counter(cci_pmu, idx)))
dev_err(&cci_pmu->plat_device->dev, "Invalid CCI PMU counter %d\n", idx);
else
- pmu_write_register(value, idx, CCI_PMU_CNTR);
+ pmu_write_register(cci_pmu, value, idx, CCI_PMU_CNTR);
}

static u64 pmu_event_update(struct perf_event *event)
@@ -427,7 +430,7 @@ static irqreturn_t pmu_handle_irq(int irq_num, void *dev)
{
unsigned long flags;
struct cci_pmu *cci_pmu = dev;
- struct cci_pmu_hw_events *events = &pmu->hw_events;
+ struct cci_pmu_hw_events *events = &cci_pmu->hw_events;
int idx, handled = IRQ_NONE;

raw_spin_lock_irqsave(&events->pmu_lock, flags);
@@ -446,11 +449,12 @@ static irqreturn_t pmu_handle_irq(int irq_num, void *dev)
hw_counter = &event->hw;

/* Did this counter overflow? */
- if (!(pmu_read_register(idx, CCI_PMU_OVRFLW) &
+ if (!(pmu_read_register(cci_pmu, idx, CCI_PMU_OVRFLW) &
CCI_PMU_OVRFLW_FLAG))
continue;

- pmu_write_register(CCI_PMU_OVRFLW_FLAG, idx, CCI_PMU_OVRFLW);
+ pmu_write_register(cci_pmu, CCI_PMU_OVRFLW_FLAG, idx,
+ CCI_PMU_OVRFLW);

pmu_event_update(event);
pmu_event_set_period(event);
@@ -549,10 +553,10 @@ static void cci_pmu_start(struct perf_event *event, int pmu_flags)

/* Configure the event to count, unless you are counting cycles */
if (idx != CCI_PMU_CYCLE_CNTR_IDX)
- pmu_set_event(idx, hwc->config_base);
+ pmu_set_event(cci_pmu, idx, hwc->config_base);

pmu_event_set_period(event);
- pmu_enable_counter(idx);
+ pmu_enable_counter(cci_pmu, idx);

raw_spin_unlock_irqrestore(&hw_events->pmu_lock, flags);
}
@@ -575,7 +579,7 @@ static void cci_pmu_stop(struct perf_event *event, int pmu_flags)
* We always reprogram the counter, so ignore PERF_EF_UPDATE. See
* cci_pmu_start()
*/
- pmu_disable_counter(idx);
+ pmu_disable_counter(cci_pmu, idx);
pmu_event_update(event);
hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
}
@@ -779,20 +783,27 @@ static int cci_pmu_event_init(struct perf_event *event)
return err;
}

-static ssize_t pmu_attr_cpumask_show(struct device *dev,
+static ssize_t pmu_cpumask_attr_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
+ struct dev_ext_attribute *eattr = container_of(attr,
+ struct dev_ext_attribute, attr);
+ struct cci_pmu *cci_pmu = eattr->var;
+
int n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
- cpumask_pr_args(&pmu->cpus));
+ cpumask_pr_args(&cci_pmu->cpus));
buf[n++] = '\n';
buf[n] = '\0';
return n;
}

-static DEVICE_ATTR(cpumask, S_IRUGO, pmu_attr_cpumask_show, NULL);
+static struct dev_ext_attribute pmu_cpumask_attr = {
+ __ATTR(cpumask, S_IRUGO, pmu_cpumask_attr_show, NULL),
+ NULL, /* Populated in cci_pmu_init */
+};

static struct attribute *pmu_attrs[] = {
- &dev_attr_cpumask.attr,
+ &pmu_cpumask_attr.attr.attr,
NULL,
};

@@ -808,6 +819,8 @@ static const struct attribute_group *pmu_attr_groups[] = {
static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
{
char *name = cci_pmu->model->name;
+
+ pmu_cpumask_attr.var = cci_pmu;
cci_pmu->pmu = (struct pmu) {
.name = cci_pmu->model->name,
.task_ctx_nr = perf_invalid_context,
@@ -831,12 +844,14 @@ static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
static int cci_pmu_cpu_notifier(struct notifier_block *self,
unsigned long action, void *hcpu)
{
+ struct cci_pmu *cci_pmu = container_of(self,
+ struct cci_pmu, cpu_nb);
unsigned int cpu = (long)hcpu;
unsigned int target;

switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DOWN_PREPARE:
- if (!cpumask_test_and_clear_cpu(cpu, &pmu->cpus))
+ if (!cpumask_test_and_clear_cpu(cpu, &cci_pmu->cpus))
break;
target = cpumask_any_but(cpu_online_mask, cpu);
if (target < 0) // UP, last CPU
@@ -845,7 +860,7 @@ static int cci_pmu_cpu_notifier(struct notifier_block *self,
* TODO: migrate context once core races on event->ctx have
* been fixed.
*/
- cpumask_set_cpu(target, &pmu->cpus);
+ cpumask_set_cpu(target, &cci_pmu->cpus);
default:
break;
}
@@ -853,15 +868,6 @@ static int cci_pmu_cpu_notifier(struct notifier_block *self,
return NOTIFY_OK;
}

-static struct notifier_block cci_pmu_cpu_nb = {
- .notifier_call = cci_pmu_cpu_notifier,
- /*
- * to migrate uncore events, our notifier should be executed
- * before perf core's notifier.
- */
- .priority = CPU_PRI_PERF + 1,
-};
-
static struct cci_pmu_model cci_pmu_models[] = {
[CCI_REV_R0] = {
.name = "CCI_400",
@@ -935,6 +941,7 @@ static bool is_duplicate_irq(int irq, int *irqs, int nr_irqs)
static int cci_pmu_probe(struct platform_device *pdev)
{
struct resource *res;
+ struct cci_pmu *cci_pmu;
int i, ret, irq;
const struct cci_pmu_model *model;

@@ -944,30 +951,30 @@ static int cci_pmu_probe(struct platform_device *pdev)
return -ENODEV;
}

- pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
- if (!pmu)
+ cci_pmu = devm_kzalloc(&pdev->dev, sizeof(*cci_pmu), GFP_KERNEL);
+ if (!cci_pmu)
return -ENOMEM;

- pmu->model = model;
+ cci_pmu->model = model;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- pmu->base = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(pmu->base))
+ cci_pmu->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(cci_pmu->base))
return -ENOMEM;

/*
* CCI PMU has 5 overflow signals - one per counter; but some may be tied
* together to a common interrupt.
*/
- pmu->nr_irqs = 0;
+ cci_pmu->nr_irqs = 0;
for (i = 0; i < CCI_PMU_MAX_HW_EVENTS; i++) {
irq = platform_get_irq(pdev, i);
if (irq < 0)
break;

- if (is_duplicate_irq(irq, pmu->irqs, pmu->nr_irqs))
+ if (is_duplicate_irq(irq, cci_pmu->irqs, cci_pmu->nr_irqs))
continue;

- pmu->irqs[pmu->nr_irqs++] = irq;
+ cci_pmu->irqs[cci_pmu->nr_irqs++] = irq;
}

/*
@@ -980,20 +987,31 @@ static int cci_pmu_probe(struct platform_device *pdev)
return -EINVAL;
}

- raw_spin_lock_init(&pmu->hw_events.pmu_lock);
- mutex_init(&pmu->reserve_mutex);
- atomic_set(&pmu->active_events, 0);
- cpumask_set_cpu(smp_processor_id(), &pmu->cpus);
+ raw_spin_lock_init(&cci_pmu->hw_events.pmu_lock);
+ mutex_init(&cci_pmu->reserve_mutex);
+ atomic_set(&cci_pmu->active_events, 0);
+ cpumask_set_cpu(smp_processor_id(), &cci_pmu->cpus);

- ret = register_cpu_notifier(&cci_pmu_cpu_nb);
+ cci_pmu->cpu_nb = (struct notifier_block) {
+ .notifier_call = cci_pmu_cpu_notifier,
+ /*
+ * to migrate uncore events, our notifier should be executed
+ * before perf core's notifier.
+ */
+ .priority = CPU_PRI_PERF + 1,
+ };
+
+ ret = register_cpu_notifier(&cci_pmu->cpu_nb);
if (ret)
return ret;

- ret = cci_pmu_init(pmu, pdev);
- if (ret)
+ ret = cci_pmu_init(cci_pmu, pdev);
+ if (ret) {
+ unregister_cpu_notifier(&cci_pmu->cpu_nb);
return ret;
+ }

- pr_info("ARM %s PMU driver probed", pmu->model->name);
+ pr_info("ARM %s PMU driver probed", cci_pmu->model->name);
return 0;
}

--
1.7.9.5

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