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Commit 712df65c authored by Taku Izumi's avatar Taku Izumi Committed by Ingo Molnar
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perf/x86/intel/uncore: Fix multi-segment problem of perf_event_intel_uncore 



In multi-segment system, uncore devices may belong to buses whose segment
number is other than 0:

  ....
  0000:ff:10.5 System peripheral: Intel Corporation Xeon E5 v3/Core i7 Scratchpad & Semaphore Registers (rev 03)
  ...
  0001:7f:10.5 System peripheral: Intel Corporation Xeon E5 v3/Core i7 Scratchpad & Semaphore Registers (rev 03)
  ...
  0001:bf:10.5 System peripheral: Intel Corporation Xeon E5 v3/Core i7 Scratchpad & Semaphore Registers (rev 03)
  ...
  0001:ff:10.5 System peripheral: Intel Corporation Xeon E5 v3/Core i7 Scratchpad & Semaphore Registers (rev 03
  ...

In that case, relation of bus number and physical id may be broken
because "uncore_pcibus_to_physid" doesn't take account of PCI segment.
For example, bus 0000:ff and 0001:ff uses the same entry of
"uncore_pcibus_to_physid" array.

This patch fixes this problem by introducing the segment-aware pci2phy_map instead.

Signed-off-by: default avatarTaku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1443096621-4119-1-git-send-email-izumi.taku@jp.fujitsu.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 7ce1346a

arch/x86/kernel/cpu/perf_event_intel_uncore.c

+58 −3
Original line number Diff line number Diff line
@@ -7,7 +7,8 @@ struct intel_uncore_type **uncore_pci_uncores = empty_uncore; 
static bool pcidrv_registered;

struct pci_driver *uncore_pci_driver;

/* pci bus to socket mapping */

int uncore_pcibus_to_physid[256] = { [0 ... 255] = -1, };

DEFINE_RAW_SPINLOCK(pci2phy_map_lock);

struct list_head pci2phy_map_head = LIST_HEAD_INIT(pci2phy_map_head);

struct pci_dev *uncore_extra_pci_dev[UNCORE_SOCKET_MAX][UNCORE_EXTRA_PCI_DEV_MAX];



static DEFINE_RAW_SPINLOCK(uncore_box_lock);
@@ -20,6 +21,59 @@ static struct event_constraint uncore_constraint_fixed = 
struct event_constraint uncore_constraint_empty =

	EVENT_CONSTRAINT(0, 0, 0);



int uncore_pcibus_to_physid(struct pci_bus *bus)

{

	struct pci2phy_map *map;

	int phys_id = -1;



	raw_spin_lock(&pci2phy_map_lock);

	list_for_each_entry(map, &pci2phy_map_head, list) {

		if (map->segment == pci_domain_nr(bus)) {

			phys_id = map->pbus_to_physid[bus->number];

			break;

		}

	}

	raw_spin_unlock(&pci2phy_map_lock);



	return phys_id;

}



struct pci2phy_map *__find_pci2phy_map(int segment)

{

	struct pci2phy_map *map, *alloc = NULL;

	int i;



	lockdep_assert_held(&pci2phy_map_lock);



lookup:

	list_for_each_entry(map, &pci2phy_map_head, list) {

		if (map->segment == segment)

			goto end;

	}



	if (!alloc) {

		raw_spin_unlock(&pci2phy_map_lock);

		alloc = kmalloc(sizeof(struct pci2phy_map), GFP_KERNEL);

		raw_spin_lock(&pci2phy_map_lock);



		if (!alloc)

			return NULL;



		goto lookup;

	}



	map = alloc;

	alloc = NULL;

	map->segment = segment;

	for (i = 0; i < 256; i++)

		map->pbus_to_physid[i] = -1;

	list_add_tail(&map->list, &pci2phy_map_head);



end:

	kfree(alloc);

	return map;

}



ssize_t uncore_event_show(struct kobject *kobj,

			  struct kobj_attribute *attr, char *buf)

{
@@ -809,7 +863,7 @@ static int uncore_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id 
	int phys_id;

	bool first_box = false;



	phys_id = uncore_pcibus_to_physid[pdev->bus->number];

	phys_id = uncore_pcibus_to_physid(pdev->bus);

	if (phys_id < 0)

		return -ENODEV;
@@ -856,9 +910,10 @@ static void uncore_pci_remove(struct pci_dev *pdev) 
{

	struct intel_uncore_box *box = pci_get_drvdata(pdev);

	struct intel_uncore_pmu *pmu;

	int i, cpu, phys_id = uncore_pcibus_to_physid[pdev->bus->number];

	int i, cpu, phys_id;

	bool last_box = false;



	phys_id = uncore_pcibus_to_physid(pdev->bus);

	box = pci_get_drvdata(pdev);

	if (!box) {

		for (i = 0; i < UNCORE_EXTRA_PCI_DEV_MAX; i++) {

arch/x86/kernel/cpu/perf_event_intel_uncore.h

+11 −1
Original line number Diff line number Diff line
@@ -117,6 +117,15 @@ struct uncore_event_desc { 
	const char *config;

};



struct pci2phy_map {

	struct list_head list;

	int segment;

	int pbus_to_physid[256];

};



int uncore_pcibus_to_physid(struct pci_bus *bus);

struct pci2phy_map *__find_pci2phy_map(int segment);



ssize_t uncore_event_show(struct kobject *kobj,

			  struct kobj_attribute *attr, char *buf);
@@ -317,7 +326,8 @@ u64 uncore_shared_reg_config(struct intel_uncore_box *box, int idx); 
extern struct intel_uncore_type **uncore_msr_uncores;

extern struct intel_uncore_type **uncore_pci_uncores;

extern struct pci_driver *uncore_pci_driver;

extern int uncore_pcibus_to_physid[256];

extern raw_spinlock_t pci2phy_map_lock;

extern struct list_head pci2phy_map_head;

extern struct pci_dev *uncore_extra_pci_dev[UNCORE_SOCKET_MAX][UNCORE_EXTRA_PCI_DEV_MAX];

extern struct event_constraint uncore_constraint_empty;

arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c

+13 −3
Original line number Diff line number Diff line
@@ -420,15 +420,25 @@ static void snb_uncore_imc_event_del(struct perf_event *event, int flags) 
static int snb_pci2phy_map_init(int devid)

{

	struct pci_dev *dev = NULL;

	int bus;

	struct pci2phy_map *map;

	int bus, segment;



	dev = pci_get_device(PCI_VENDOR_ID_INTEL, devid, dev);

	if (!dev)

		return -ENOTTY;



	bus = dev->bus->number;

	segment = pci_domain_nr(dev->bus);



	uncore_pcibus_to_physid[bus] = 0;

	raw_spin_lock(&pci2phy_map_lock);

	map = __find_pci2phy_map(segment);

	if (!map) {

		raw_spin_unlock(&pci2phy_map_lock);

		pci_dev_put(dev);

		return -ENOMEM;

	}

	map->pbus_to_physid[bus] = 0;

	raw_spin_unlock(&pci2phy_map_lock);



	pci_dev_put(dev);

arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c

+24 −8
Original line number Diff line number Diff line
@@ -1087,7 +1087,8 @@ static struct pci_driver snbep_uncore_pci_driver = { 
static int snbep_pci2phy_map_init(int devid)

{

	struct pci_dev *ubox_dev = NULL;

	int i, bus, nodeid;

	int i, bus, nodeid, segment;

	struct pci2phy_map *map;

	int err = 0;

	u32 config = 0;
@@ -1106,16 +1107,27 @@ static int snbep_pci2phy_map_init(int devid) 
		err = pci_read_config_dword(ubox_dev, 0x54, &config);

		if (err)

			break;



		segment = pci_domain_nr(ubox_dev->bus);

		raw_spin_lock(&pci2phy_map_lock);

		map = __find_pci2phy_map(segment);

		if (!map) {

			raw_spin_unlock(&pci2phy_map_lock);

			err = -ENOMEM;

			break;

		}



		/*

		 * every three bits in the Node ID mapping register maps

		 * to a particular node.

		 */

		for (i = 0; i < 8; i++) {

			if (nodeid == ((config >> (3 * i)) & 0x7)) {

				uncore_pcibus_to_physid[bus] = i;

				map->pbus_to_physid[bus] = i;

				break;

			}

		}

		raw_spin_unlock(&pci2phy_map_lock);

	}



	if (!err) {
@@ -1123,13 +1135,17 @@ static int snbep_pci2phy_map_init(int devid) 
		 * For PCI bus with no UBOX device, find the next bus

		 * that has UBOX device and use its mapping.

		 */

		raw_spin_lock(&pci2phy_map_lock);

		list_for_each_entry(map, &pci2phy_map_head, list) {

			i = -1;

			for (bus = 255; bus >= 0; bus--) {

			if (uncore_pcibus_to_physid[bus] >= 0)

				i = uncore_pcibus_to_physid[bus];

				if (map->pbus_to_physid[bus] >= 0)

					i = map->pbus_to_physid[bus];

				else

				uncore_pcibus_to_physid[bus] = i;

					map->pbus_to_physid[bus] = i;

			}

		}

		raw_spin_unlock(&pci2phy_map_lock);

	}



	pci_dev_put(ubox_dev);