Commit 4118bca2 authored by Kan Liang's avatar Kan Liang Committed by Yunying Sun
Browse files

perf/x86/uncore: Support per PMU cpumask 

mainline inclusion
from mainline-v6.11-rc1
commit c74443d92f68f07c03ae242ced554b749e6c6736
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/IAGJQ7
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c74443d92f68f07c03ae242ced554b749e6c6736



-------------------------------------

The cpumask of some uncore units, e.g., CXL uncore units, may be wrong
under some configurations. Perf may access an uncore counter of a
non-existent uncore unit.

The uncore driver assumes that all uncore units are symmetric among
dies. A global cpumask is shared among all uncore PMUs. However, some
CXL uncore units may only be available on some dies.

A per PMU cpumask is introduced to track the CPU mask of this PMU.
The driver searches the unit control RB tree to check whether the PMU is
available on a given die, and updates the per PMU cpumask accordingly.

Intel-SIG: commit c74443d92f68 perf/x86/uncore: Support per PMU cpumask
Backport SPR/EMR CXL and HBM perfmon support to kernel v5.10

Signed-off-by: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: default avatarYunying Sun <yunying.sun@intel.com>
Link: https://lore.kernel.org/r/20240614134631.1092359-3-kan.liang@linux.intel.com


Signed-off-by: default avatarYunying Sun <yunying.sun@intel.com>
parent bfb1b7f2

arch/x86/events/intel/uncore.c

+26 −5
Original line number Diff line number Diff line
@@ -835,7 +835,9 @@ static void uncore_pmu_disable(struct pmu *pmu) 
static ssize_t uncore_get_attr_cpumask(struct device *dev,

				struct device_attribute *attr, char *buf)

{

	return cpumap_print_to_pagebuf(true, buf, &uncore_cpu_mask);

	struct intel_uncore_pmu *pmu = container_of(dev_get_drvdata(dev), struct intel_uncore_pmu, pmu);



	return cpumap_print_to_pagebuf(true, buf, &pmu->cpu_mask);

}



static DEVICE_ATTR(cpumask, S_IRUGO, uncore_get_attr_cpumask, NULL);
@@ -1445,6 +1447,18 @@ static void uncore_pci_exit(void) 
	}

}



static bool uncore_die_has_box(struct intel_uncore_type *type,

			       int die, unsigned int pmu_idx)

{

	if (!type->boxes)

		return true;



	if (intel_uncore_find_discovery_unit_id(type->boxes, die, pmu_idx) < 0)

		return false;



	return true;

}



static void uncore_change_type_ctx(struct intel_uncore_type *type, int old_cpu,

				   int new_cpu)

{
@@ -1460,18 +1474,25 @@ static void uncore_change_type_ctx(struct intel_uncore_type *type, int old_cpu, 


		if (old_cpu < 0) {

			WARN_ON_ONCE(box->cpu != -1);

			if (uncore_die_has_box(type, die, pmu->pmu_idx)) {

				box->cpu = new_cpu;

				cpumask_set_cpu(new_cpu, &pmu->cpu_mask);

			}

			continue;

		}



		WARN_ON_ONCE(box->cpu != old_cpu);

		WARN_ON_ONCE(box->cpu != -1 && box->cpu != old_cpu);

		box->cpu = -1;

		cpumask_clear_cpu(old_cpu, &pmu->cpu_mask);

		if (new_cpu < 0)

			continue;



		if (!uncore_die_has_box(type, die, pmu->pmu_idx))

			continue;

		uncore_pmu_cancel_hrtimer(box);

		perf_pmu_migrate_context(&pmu->pmu, old_cpu, new_cpu);

		box->cpu = new_cpu;

		cpumask_set_cpu(new_cpu, &pmu->cpu_mask);

	}

}
@@ -1494,7 +1515,7 @@ static void uncore_box_unref(struct intel_uncore_type **types, int id) 
		pmu = type->pmus;

		for (i = 0; i < type->num_boxes; i++, pmu++) {

			box = pmu->boxes[id];

			if (box && atomic_dec_return(&box->refcnt) == 0)

			if (box && box->cpu >= 0 && atomic_dec_return(&box->refcnt) == 0)

				uncore_box_exit(box);

		}

	}
@@ -1584,7 +1605,7 @@ static int uncore_box_ref(struct intel_uncore_type **types, 
		pmu = type->pmus;

		for (i = 0; i < type->num_boxes; i++, pmu++) {

			box = pmu->boxes[id];

			if (box && atomic_inc_return(&box->refcnt) == 1)

			if (box && box->cpu >= 0 && atomic_inc_return(&box->refcnt) == 1)

				uncore_box_init(box);

		}

	}

arch/x86/events/intel/uncore.h

+2 −0
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ struct intel_uncore_type { 
	const struct attribute_group *attr_groups[4];

	const struct attribute_group **attr_update;

	struct pmu *pmu; /* for custom pmu ops */

	struct rb_root *boxes;

	/*

	 * Uncore PMU would store relevant platform topology configuration here

	 * to identify which platform component each PMON block of that type is
@@ -123,6 +124,7 @@ struct intel_uncore_pmu { 
	int				func_id;

	bool				registered;

	atomic_t			activeboxes;

	cpumask_t			cpu_mask;

	struct intel_uncore_type	*type;

	struct intel_uncore_box		**boxes;

};

arch/x86/events/intel/uncore_discovery.c

+58 −0
Original line number Diff line number Diff line
@@ -122,6 +122,64 @@ get_uncore_discovery_type(struct uncore_unit_discovery *unit) 
	return add_uncore_discovery_type(unit);

}



static inline int pmu_idx_cmp(const void *key, const struct rb_node *b)

{

	struct intel_uncore_discovery_unit *unit;

	const unsigned int *id = key;



	unit = rb_entry(b, struct intel_uncore_discovery_unit, node);



	if (unit->pmu_idx > *id)

		return -1;

	else if (unit->pmu_idx < *id)

		return 1;



	return 0;

}



static struct intel_uncore_discovery_unit *

intel_uncore_find_discovery_unit(struct rb_root *units, int die,

				 unsigned int pmu_idx)

{

	struct intel_uncore_discovery_unit *unit;

	struct rb_node *pos;



	if (!units)

		return NULL;



	pos = rb_find_first(&pmu_idx, units, pmu_idx_cmp);

	if (!pos)

		return NULL;

	unit = rb_entry(pos, struct intel_uncore_discovery_unit, node);



	if (die < 0)

		return unit;



	for (; pos; pos = rb_next(pos)) {

		unit = rb_entry(pos, struct intel_uncore_discovery_unit, node);



		if (unit->pmu_idx != pmu_idx)

			break;



		if (unit->die == die)

			return unit;

	}



	return NULL;

}



int intel_uncore_find_discovery_unit_id(struct rb_root *units, int die,

					unsigned int pmu_idx)

{

	struct intel_uncore_discovery_unit *unit;



	unit = intel_uncore_find_discovery_unit(units, die, pmu_idx);

	if (unit)

		return unit->id;



	return -1;

}



static inline bool unit_less(struct rb_node *a, const struct rb_node *b)

{

	struct intel_uncore_discovery_unit *a_node, *b_node;

arch/x86/events/intel/uncore_discovery.h

+3 −0
Original line number Diff line number Diff line
@@ -168,3 +168,6 @@ u64 intel_generic_uncore_pci_read_counter(struct intel_uncore_box *box, 


struct intel_uncore_type **

intel_uncore_generic_init_uncores(enum uncore_access_type type_id, int num_extra);



int intel_uncore_find_discovery_unit_id(struct rb_root *units, int die,

					unsigned int pmu_idx);