dmaengine: idxd: Clean up cpumask and hotplug for perfmon

The idxd PMU is system-wide scope, which is supported by the generic
perf_event subsystem now.

Set the scope for the idxd PMU and remove all the cpumask and hotplug
codes.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20240802151643.1691631-6-kan.liang@linux.intel.com

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 868b724a3b75bb3648f34801cf5c5eedc1489cf4..d84e21daa99122aea8aff984617da9b0b3fd43e5 100644 (file)
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -124,7 +124,6 @@ struct idxd_pmu {
 
        struct pmu pmu;
        char name[IDXD_NAME_SIZE];
-       int cpu;
 
        int n_counters;
        int counter_width;
@@ -135,8 +134,6 @@ struct idxd_pmu {
 
        unsigned long supported_filters;
        int n_filters;
-
-       struct hlist_node cpuhp_node;
 };
 
 #define IDXD_MAX_PRIORITY      0xf
@@ -803,14 +800,10 @@ void idxd_user_counter_increment(struct idxd_wq *wq, u32 pasid, int index);
 int perfmon_pmu_init(struct idxd_device *idxd);
 void perfmon_pmu_remove(struct idxd_device *idxd);
 void perfmon_counter_overflow(struct idxd_device *idxd);
-void perfmon_init(void);
-void perfmon_exit(void);
 #else
 static inline int perfmon_pmu_init(struct idxd_device *idxd) { return 0; }
 static inline void perfmon_pmu_remove(struct idxd_device *idxd) {}
 static inline void perfmon_counter_overflow(struct idxd_device *idxd) {}
-static inline void perfmon_init(void) {}
-static inline void perfmon_exit(void) {}
 #endif
 
 /* debugfs */

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 21f6905b554d84dbb07d5c9f388e4122a8fe63e6..5725ea82c4099da2e15d802a36c9c83f06259258 100644 (file)
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -878,8 +878,6 @@ static int __init idxd_init_module(void)
        else
                support_enqcmd = true;
 
-       perfmon_init();
-
        err = idxd_driver_register(&idxd_drv);
        if (err < 0)
                goto err_idxd_driver_register;
@@ -928,7 +926,6 @@ static void __exit idxd_exit_module(void)
        idxd_driver_unregister(&idxd_drv);
        pci_unregister_driver(&idxd_pci_driver);
        idxd_cdev_remove();
-       perfmon_exit();
        idxd_remove_debugfs();
 }
 module_exit(idxd_exit_module);

diff --git a/drivers/dma/idxd/perfmon.c b/drivers/dma/idxd/perfmon.c
index 5e94247e1ea703086365a01d1d124e5ef2acb5de..f511cf15845becad922ac5da3c844b1b3ee5112c 100644 (file)
--- a/drivers/dma/idxd/perfmon.c
+++ b/drivers/dma/idxd/perfmon.c
@@ -6,29 +6,6 @@
 #include "idxd.h"
 #include "perfmon.h"
 
-static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
-                           char *buf);
-
-static cpumask_t               perfmon_dsa_cpu_mask;
-static bool                    cpuhp_set_up;
-static enum cpuhp_state                cpuhp_slot;
-
-/*
- * perf userspace reads this attribute to determine which cpus to open
- * counters on.  It's connected to perfmon_dsa_cpu_mask, which is
- * maintained by the cpu hotplug handlers.
- */
-static DEVICE_ATTR_RO(cpumask);
-
-static struct attribute *perfmon_cpumask_attrs[] = {
-       &dev_attr_cpumask.attr,
-       NULL,
-};
-
-static struct attribute_group cpumask_attr_group = {
-       .attrs = perfmon_cpumask_attrs,
-};
-
 /*
  * These attributes specify the bits in the config word that the perf
  * syscall uses to pass the event ids and categories to perfmon.
@@ -67,16 +44,9 @@ static struct attribute_group perfmon_format_attr_group = {
 
 static const struct attribute_group *perfmon_attr_groups[] = {
        &perfmon_format_attr_group,
-       &cpumask_attr_group,
        NULL,
 };
 
-static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
-                           char *buf)
-{
-       return cpumap_print_to_pagebuf(true, buf, &perfmon_dsa_cpu_mask);
-}
-
 static bool is_idxd_event(struct idxd_pmu *idxd_pmu, struct perf_event *event)
 {
        return &idxd_pmu->pmu == event->pmu;
@@ -217,7 +187,6 @@ static int perfmon_pmu_event_init(struct perf_event *event)
                return -EINVAL;
 
        event->hw.event_base = ioread64(PERFMON_TABLE_OFFSET(idxd));
-       event->cpu = idxd->idxd_pmu->cpu;
        event->hw.config = event->attr.config;
 
        if (event->group_leader != event)
@@ -488,6 +457,7 @@ static void idxd_pmu_init(struct idxd_pmu *idxd_pmu)
        idxd_pmu->pmu.stop              = perfmon_pmu_event_stop;
        idxd_pmu->pmu.read              = perfmon_pmu_event_update;
        idxd_pmu->pmu.capabilities      = PERF_PMU_CAP_NO_EXCLUDE;
+       idxd_pmu->pmu.scope             = PERF_PMU_SCOPE_SYS_WIDE;
        idxd_pmu->pmu.module            = THIS_MODULE;
 }
 
@@ -496,59 +466,17 @@ void perfmon_pmu_remove(struct idxd_device *idxd)
        if (!idxd->idxd_pmu)
                return;
 
-       cpuhp_state_remove_instance(cpuhp_slot, &idxd->idxd_pmu->cpuhp_node);
        perf_pmu_unregister(&idxd->idxd_pmu->pmu);
        kfree(idxd->idxd_pmu);
        idxd->idxd_pmu = NULL;
 }
 
-static int perf_event_cpu_online(unsigned int cpu, struct hlist_node *node)
-{
-       struct idxd_pmu *idxd_pmu;
-
-       idxd_pmu = hlist_entry_safe(node, typeof(*idxd_pmu), cpuhp_node);
-
-       /* select the first online CPU as the designated reader */
-       if (cpumask_empty(&perfmon_dsa_cpu_mask)) {
-               cpumask_set_cpu(cpu, &perfmon_dsa_cpu_mask);
-               idxd_pmu->cpu = cpu;
-       }
-
-       return 0;
-}
-
-static int perf_event_cpu_offline(unsigned int cpu, struct hlist_node *node)
-{
-       struct idxd_pmu *idxd_pmu;
-       unsigned int target;
-
-       idxd_pmu = hlist_entry_safe(node, typeof(*idxd_pmu), cpuhp_node);
-
-       if (!cpumask_test_and_clear_cpu(cpu, &perfmon_dsa_cpu_mask))
-               return 0;
-
-       target = cpumask_any_but(cpu_online_mask, cpu);
-       /* migrate events if there is a valid target */
-       if (target < nr_cpu_ids) {
-               cpumask_set_cpu(target, &perfmon_dsa_cpu_mask);
-               perf_pmu_migrate_context(&idxd_pmu->pmu, cpu, target);
-       }
-
-       return 0;
-}
-
 int perfmon_pmu_init(struct idxd_device *idxd)
 {
        union idxd_perfcap perfcap;
        struct idxd_pmu *idxd_pmu;
        int rc = -ENODEV;
 
-       /*
-        * perfmon module initialization failed, nothing to do
-        */
-       if (!cpuhp_set_up)
-               return -ENODEV;
-
        /*
         * If perfmon_offset or num_counters is 0, it means perfmon is
         * not supported on this hardware.
@@ -624,11 +552,6 @@ int perfmon_pmu_init(struct idxd_device *idxd)
        if (rc)
                goto free;
 
-       rc = cpuhp_state_add_instance(cpuhp_slot, &idxd_pmu->cpuhp_node);
-       if (rc) {
-               perf_pmu_unregister(&idxd->idxd_pmu->pmu);
-               goto free;
-       }
 out:
        return rc;
 free:
@@ -637,22 +560,3 @@ free:
 
        goto out;
 }
-
-void __init perfmon_init(void)
-{
-       int rc = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
-                                        "driver/dma/idxd/perf:online",
-                                        perf_event_cpu_online,
-                                        perf_event_cpu_offline);
-       if (WARN_ON(rc < 0))
-               return;
-
-       cpuhp_slot = rc;
-       cpuhp_set_up = true;
-}
-
-void __exit perfmon_exit(void)
-{
-       if (cpuhp_set_up)
-               cpuhp_remove_multi_state(cpuhp_slot);
-}