perf/arm-cci: Allow building as a module

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>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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 33b47c292d79..e6fadc8e1178 100644
--- a/drivers/perf/arm-cci.c
+++ b/drivers/perf/arm-cci.c
@@ -1407,6 +1407,7 @@ 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,
@@ -1572,6 +1573,7 @@ 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)
 {
@@ -1693,14 +1695,27 @@ 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");