* [PATCH v2 2/3] perf/arm-cci: Remove pointless PMU disabling
2018-05-14 13:34 [PATCH v2 0/3] perf: make Arm CCI driver modular Robin Murphy
2018-05-14 13:34 ` [PATCH v2 1/3] perf/arm-cc*: Fix MODULE_LICENSE() tags Robin Murphy
@ 2018-05-14 13:34 ` Robin Murphy
2018-05-14 13:34 ` [PATCH v2 3/3] perf/arm-cci: Allow building as a module Robin Murphy
2 siblings, 0 replies; 4+ messages in thread
From: Robin Murphy @ 2018-05-14 13:34 UTC (permalink / raw)
To: linux-arm-kernel
The CCI PMU driver bears some legacy remnants of the arm_pmu framework
from when it was split in c6f85cb4305b ("bus: cci: move away from
arm_pmu framework"). In particular this perf_pmu_{dis,en}able() dance
around pmu->add which was fixed for arm_pmu in a9e469d1c89b
("drivers/perf: arm_pmu: remove pointless PMU disabling").
For the exact same reasons (i.e. perf core already does this around the
call anyway), give cci_pmu_add() the exact same change, which also
prevents having to export those core functions to build it as a module.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
v2: Add Mark's ack
drivers/perf/arm-cci.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c
index 53c774b20563..7029d8fe8f44 100644
--- a/drivers/perf/arm-cci.c
+++ b/drivers/perf/arm-cci.c
@@ -1184,16 +1184,11 @@ static int cci_pmu_add(struct perf_event *event, int flags)
struct cci_pmu_hw_events *hw_events = &cci_pmu->hw_events;
struct hw_perf_event *hwc = &event->hw;
int idx;
- int err = 0;
-
- perf_pmu_disable(event->pmu);
/* If we don't have a space for the counter then finish early. */
idx = pmu_get_event_idx(hw_events, event);
- if (idx < 0) {
- err = idx;
- goto out;
- }
+ if (idx < 0)
+ return idx;
event->hw.idx = idx;
hw_events->events[idx] = event;
@@ -1205,9 +1200,7 @@ static int cci_pmu_add(struct perf_event *event, int flags)
/* Propagate our changes to the userspace mapping. */
perf_event_update_userpage(event);
-out:
- perf_pmu_enable(event->pmu);
- return err;
+ return 0;
}
static void cci_pmu_del(struct perf_event *event, int flags)
--
2.17.0.dirty
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2 3/3] perf/arm-cci: Allow building as a module
2018-05-14 13:34 [PATCH v2 0/3] perf: make Arm CCI driver modular Robin Murphy
2018-05-14 13:34 ` [PATCH v2 1/3] perf/arm-cc*: Fix MODULE_LICENSE() tags Robin Murphy
2018-05-14 13:34 ` [PATCH v2 2/3] perf/arm-cci: Remove pointless PMU disabling Robin Murphy
@ 2018-05-14 13:34 ` Robin Murphy
2 siblings, 0 replies; 4+ messages in thread
From: Robin Murphy @ 2018-05-14 13:34 UTC (permalink / raw)
To: linux-arm-kernel
Fill in the few extra bits and annotations needed to make the driver
work properly as a module, and jiggle the Kconfig to expose the
driver-level ARM_CCI_PMU option.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
v2: Move ARM/64 dependency up accordingly
drivers/perf/Kconfig | 34 ++++++++++++++++++----------------
drivers/perf/arm-cci.c | 17 ++++++++++++++++-
2 files changed, 34 insertions(+), 17 deletions(-)
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 28bb5a029558..110330ecf714 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -6,30 +6,32 @@ menu "Performance monitor support"
depends on PERF_EVENTS
config ARM_CCI_PMU
- bool
+ tristate "ARM CCI PMU driver"
+ depends on (ARM && CPU_V7) || ARM64
select ARM_CCI
+ help
+ Support for PMU events monitoring on the ARM CCI (Cache Coherent
+ Interconnect) family of products.
+
+ If compiled as a module, it will be called arm-cci.
config ARM_CCI400_PMU
- bool "ARM CCI400 PMU support"
- depends on (ARM && CPU_V7) || ARM64
+ bool "support CCI-400"
+ default y
+ depends on ARM_CCI_PMU
select ARM_CCI400_COMMON
- select ARM_CCI_PMU
help
- Support for PMU events monitoring on the ARM CCI-400 (cache coherent
- interconnect). CCI-400 supports counting events related to the
- connected slave/master interfaces.
+ CCI-400 provides 4 independent event counters counting events related
+ to the connected slave/master interfaces, plus a cycle counter.
config ARM_CCI5xx_PMU
- bool "ARM CCI-500/CCI-550 PMU support"
- depends on (ARM && CPU_V7) || ARM64
- select ARM_CCI_PMU
+ bool "support CCI-500/CCI-550"
+ default y
+ depends on ARM_CCI_PMU
help
- Support for PMU events monitoring on the ARM CCI-500/CCI-550 cache
- coherent interconnects. Both of them provide 8 independent event counters,
- which can count events pertaining to the slave/master interfaces as well
- as the internal events to the CCI.
-
- If unsure, say Y
+ CCI-500/CCI-550 both provide 8 independent event counters, which can
+ count events pertaining to the slave/master interfaces as well as the
+ internal events to the CCI.
config ARM_CCN
tristate "ARM CCN driver support"
diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c
index 7029d8fe8f44..09938dd8eb6f 100644
--- a/drivers/perf/arm-cci.c
+++ b/drivers/perf/arm-cci.c
@@ -1416,6 +1416,7 @@ static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
pmu_format_attr_group.attrs = model->format_attrs;
cci_pmu->pmu = (struct pmu) {
+ .module = THIS_MODULE,
.name = cci_pmu->model->name,
.task_ctx_nr = perf_invalid_context,
.pmu_enable = cci_pmu_enable,
@@ -1581,6 +1582,7 @@ static const struct of_device_id arm_cci_pmu_matches[] = {
#endif
{},
};
+MODULE_DEVICE_TABLE(of, arm_cci_pmu_matches);
static bool is_duplicate_irq(int irq, int *irqs, int nr_irqs)
{
@@ -1702,14 +1704,27 @@ static int cci_pmu_probe(struct platform_device *pdev)
return 0;
}
+static int cci_pmu_remove(struct platform_device *pdev)
+{
+ if (!g_cci_pmu)
+ return 0;
+
+ cpuhp_remove_state(CPUHP_AP_PERF_ARM_CCI_ONLINE);
+ perf_pmu_unregister(&g_cci_pmu->pmu);
+ g_cci_pmu = NULL;
+
+ return 0;
+}
+
static struct platform_driver cci_pmu_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = arm_cci_pmu_matches,
},
.probe = cci_pmu_probe,
+ .remove = cci_pmu_remove,
};
-builtin_platform_driver(cci_pmu_driver);
+module_platform_driver(cci_pmu_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ARM CCI PMU support");
--
2.17.0.dirty
^ permalink raw reply related [flat|nested] 4+ messages in thread