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Message-Id: <20200117133759.5729-3-roman.sudarikov@linux.intel.com>
Date: Fri, 17 Jan 2020 16:37:59 +0300
From: roman.sudarikov@...ux.intel.com
To: peterz@...radead.org, mingo@...hat.com, acme@...nel.org,
mark.rutland@....com, alexander.shishkin@...ux.intel.com,
jolsa@...hat.com, namhyung@...nel.org,
linux-kernel@...r.kernel.org, eranian@...gle.com,
bgregg@...flix.com, ak@...ux.intel.com, kan.liang@...ux.intel.com,
gregkh@...uxfoundation.org
Cc: alexander.antonov@...el.com, roman.sudarikov@...ux.intel.com
Subject: [PATCH v4 2/2] perf x86: Exposing an Uncore unit to PMON for Intel Xeon® server platform
From: Roman Sudarikov <roman.sudarikov@...ux.intel.com>
Current version supports a server line starting Intel® Xeon® Processor
Scalable Family and introduces mapping for IIO Uncore units only.
Other units can be added on demand.
IIO stack to PMON mapping is exposed through:
/sys/devices/uncore_iio_<pmu_idx>/mapping
in the following format: domain:bus
For example, on a 4-die Intel Xeon® server platform:
$ cat /sys/devices/uncore_iio_0/mapping
0000:00,0000:40,0000:80,0000:c0
Which means:
IIO PMON block 0 on die 0 belongs to IIO stack on bus 0x00, domain 0x0000
IIO PMON block 0 on die 1 belongs to IIO stack on bus 0x40, domain 0x0000
IIO PMON block 0 on die 2 belongs to IIO stack on bus 0x80, domain 0x0000
IIO PMON block 0 on die 3 belongs to IIO stack on bus 0xc0, domain 0x0000
Reviewed-by: Kan Liang <kan.liang@...ux.intel.com>
Co-developed-by: Alexander Antonov <alexander.antonov@...el.com>
Signed-off-by: Alexander Antonov <alexander.antonov@...el.com>
Signed-off-by: Roman Sudarikov <roman.sudarikov@...ux.intel.com>
---
arch/x86/events/intel/uncore_snbep.c | 160 +++++++++++++++++++++++++++
1 file changed, 160 insertions(+)
diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index b10a5ec79e48..813009b48a0f 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -273,6 +273,30 @@
#define SKX_CPUNODEID 0xc0
#define SKX_GIDNIDMAP 0xd4
+/*
+ * The CPU_BUS_NUMBER MSR returns the values of the respective CPUBUSNO CSR
+ * that BIOS programmed. MSR has package scope.
+ * | Bit | Default | Description
+ * | [63] | 00h | VALID - When set, indicates the CPU bus
+ * numbers have been initialized. (RO)
+ * |[62:48]| --- | Reserved
+ * |[47:40]| 00h | BUS_NUM_5 — Return the bus number BIOS assigned
+ * CPUBUSNO(5). (RO)
+ * |[39:32]| 00h | BUS_NUM_4 — Return the bus number BIOS assigned
+ * CPUBUSNO(4). (RO)
+ * |[31:24]| 00h | BUS_NUM_3 — Return the bus number BIOS assigned
+ * CPUBUSNO(3). (RO)
+ * |[23:16]| 00h | BUS_NUM_2 — Return the bus number BIOS assigned
+ * CPUBUSNO(2). (RO)
+ * |[15:8] | 00h | BUS_NUM_1 — Return the bus number BIOS assigned
+ * CPUBUSNO(1). (RO)
+ * | [7:0] | 00h | BUS_NUM_0 — Return the bus number BIOS assigned
+ * CPUBUSNO(0). (RO)
+ */
+#define SKX_MSR_CPU_BUS_NUMBER 0x300
+#define SKX_MSR_CPU_BUS_VALID_BIT (1ULL << 63)
+#define BUS_NUM_STRIDE 8
+
/* SKX CHA */
#define SKX_CHA_MSR_PMON_BOX_FILTER_TID (0x1ffULL << 0)
#define SKX_CHA_MSR_PMON_BOX_FILTER_LINK (0xfULL << 9)
@@ -3580,6 +3604,9 @@ static struct intel_uncore_ops skx_uncore_iio_ops = {
.read_counter = uncore_msr_read_counter,
};
+static int skx_iio_get_topology(struct intel_uncore_type *type, int max_dies);
+static int skx_iio_set_mapping(struct intel_uncore_type *type, int max_dies);
+
static struct intel_uncore_type skx_uncore_iio = {
.name = "iio",
.num_counters = 4,
@@ -3594,6 +3621,8 @@ static struct intel_uncore_type skx_uncore_iio = {
.constraints = skx_uncore_iio_constraints,
.ops = &skx_uncore_iio_ops,
.format_group = &skx_uncore_iio_format_group,
+ .get_topology = skx_iio_get_topology,
+ .set_mapping = skx_iio_set_mapping,
};
enum perf_uncore_iio_freerunning_type_id {
@@ -3780,6 +3809,137 @@ static int skx_count_chabox(void)
return hweight32(val);
}
+static inline int skx_msr_cpu_bus_read(int cpu, u64 *topology)
+{
+ u64 msr_value;
+
+ if (rdmsrl_on_cpu(cpu, SKX_MSR_CPU_BUS_NUMBER, &msr_value) ||
+ !(msr_value & SKX_MSR_CPU_BUS_VALID_BIT))
+ return -ENXIO;
+
+ *topology = msr_value;
+
+ return 0;
+}
+
+static int skx_iio_get_topology(struct intel_uncore_type *type, int max_dies)
+{
+ int ret, cpu, die, current_die;
+ struct pci_bus *bus = NULL;
+
+ /*
+ * Verified single-segment environments only; disabled for multiple
+ * segment topologies for now.
+ */
+ while ((bus = pci_find_next_bus(bus)) && !pci_domain_nr(bus))
+ ;
+ if (bus)
+ return -EPERM;
+
+ type->topology = kcalloc(max_dies, sizeof(u64), GFP_KERNEL);
+ if (!type->topology)
+ return -ENOMEM;
+
+ /*
+ * Using cpus_read_lock() to ensure cpu is not going down between
+ * looking at cpu_online_mask.
+ */
+ cpus_read_lock();
+ /* Invalid value to start loop.*/
+ current_die = -1;
+ for_each_online_cpu(cpu) {
+ die = topology_logical_die_id(cpu);
+ if (current_die == die)
+ continue;
+ ret = skx_msr_cpu_bus_read(cpu, &type->topology[die]);
+ if (ret) {
+ kfree(type->topology);
+ break;
+ }
+ current_die = die;
+ }
+ cpus_read_unlock();
+
+ return ret;
+}
+
+static inline u8 skx_iio_stack_bus(struct intel_uncore_pmu *pmu, int die)
+{
+ return pmu->type->topology[die] >> (pmu->pmu_idx * BUS_NUM_STRIDE);
+}
+
+static int skx_iio_set_box_mapping(struct intel_uncore_pmu *pmu, int max_dies)
+{
+ char *buf;
+ int die = 0;
+ /* Length of template "%04x:%02x," without null character. */
+ const int template_len = 8;
+
+ /*
+ * Root bus 0x00 is valid only for die 0 AND pmu_idx = 0.
+ * Set "0" platform mapping for PMUs which have zero stack bus and
+ * non-zero index.
+ */
+ if (!skx_iio_stack_bus(pmu, die) && pmu->pmu_idx) {
+ pmu->mapping = kzalloc(2, GFP_KERNEL);
+ if (!pmu->mapping)
+ return -ENOMEM;
+ sprintf(pmu->mapping, "0");
+ return 0;
+ }
+
+ pmu->mapping = kzalloc(max_dies * template_len + 1, GFP_KERNEL);
+ if (!pmu->mapping)
+ return -ENOMEM;
+
+ buf = pmu->mapping;
+ for (; die < max_dies; die++) {
+ buf += snprintf(buf, template_len + 1, "%04x:%02x,", 0,
+ skx_iio_stack_bus(pmu, die));
+ }
+
+ *(--buf) = '\0';
+
+ return 0;
+}
+
+static int skx_iio_set_mapping(struct intel_uncore_type *type, int max_dies)
+{
+ /*
+ * Each IIO stack (PCIe root port) has its own IIO PMON block, so each
+ * "mapping" holds bus number(s) of PCIe root port(s), which can
+ * be monitored by that IIO PMON block.
+ *
+ * For example, on 4-die Xeon platform with up to 6 IIO stacks per die
+ * and, therefore, 6 IIO PMON blocks per die, the "mapping"
+ * of IIO PMON block 0 holds "0000:00,0000:40,0000:80,0000:c0":
+ *
+ * $ cat /sys/devices/uncore_iio_0/mapping
+ * 0000:00,0000:40,0000:80,0000:c0
+ *
+ * Which means:
+ * IIO PMON 0 on die 0 belongs to PCIe RP on bus 0x00, domain 0x0000
+ * IIO PMON 0 on die 1 belongs to PCIe RP on bus 0x40, domain 0x0000
+ * IIO PMON 0 on die 2 belongs to PCIe RP on bus 0x80, domain 0x0000
+ * IIO PMON 0 on die 3 belongs to PCIe RP on bus 0xc0, domain 0x0000
+ */
+
+ int ret;
+ struct intel_uncore_pmu *pmu = type->pmus;
+
+ for (; pmu - type->pmus < type->num_boxes; pmu++) {
+ ret = skx_iio_set_box_mapping(pmu, max_dies);
+ if (ret) {
+ for (; pmu->pmu_idx > 0; --pmu)
+ kfree(pmu->mapping);
+ break;
+ }
+ }
+
+ kfree(type->topology);
+ return ret;
+}
+
void skx_uncore_cpu_init(void)
{
skx_uncore_chabox.num_boxes = skx_count_chabox();
--
2.19.1
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