Commit bbdd4df3 authored by Kan Liang's avatar Kan Liang Committed by Peter Zijlstra
Browse files

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: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarDave Jiang <dave.jiang@intel.com>
Reviewed-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20240802151643.1691631-6-kan.liang@linux.intel.com
parent a8c73b82

drivers/dma/idxd/idxd.h

+0 −7
Original line number Diff line number Diff line
@@ -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 */

drivers/dma/idxd/init.c

+0 −3
Original line number Diff line number Diff line
@@ -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);

drivers/dma/idxd/perfmon.c

+1 −97
Original line number Diff line number Diff line
@@ -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 @@ int perfmon_pmu_init(struct idxd_device *idxd) 


	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);

}