From: "Steven L. Kinney" <steven.kin...@amd.com>

Implement a perf PMU to handle IOMMUv2 PC perf events.  This PMU will handle
static counter perf events relative to the AMD IOMMUv2 Performance Counters.

To invoke the AMD IOMMUv2 PMU issue a perf tool command such as:

./perf stat -e iommuv2/config=<config-data>,config1=<config1-data>/u <command>

For example:

./perf stat -e iommuv2/config=08000000000000005,config1=0/u <command>

The resulting count will be how many IOMMUv2 totsal peripheral memory
operations were performed during the command execution window.

Signed-off-by: Steven L. Kinney <steven.kin...@amd.com>
---
 arch/x86/kernel/cpu/Makefile                 |    1 +
 arch/x86/kernel/cpu/perf_event_amd_iommuv2.c |  429 ++++++++++++++++++++++++++
 arch/x86/kernel/cpu/perf_event_amd_iommuv2.h |   42 +++
 3 files changed, 472 insertions(+)
 create mode 100644 arch/x86/kernel/cpu/perf_event_amd_iommuv2.c
 create mode 100644 arch/x86/kernel/cpu/perf_event_amd_iommuv2.h

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index a0e067d..4872b99 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_PERF_EVENTS)             += perf_event.o
 
 ifdef CONFIG_PERF_EVENTS
 obj-$(CONFIG_CPU_SUP_AMD)              += perf_event_amd.o
+obj-$(CONFIG_AMD_IOMMU_V2_PC)           += perf_event_amd_iommuv2.o
 obj-$(CONFIG_CPU_SUP_INTEL)            += perf_event_p6.o perf_event_knc.o 
perf_event_p4.o
 obj-$(CONFIG_CPU_SUP_INTEL)            += perf_event_intel_lbr.o 
perf_event_intel_ds.o perf_event_intel.o
 obj-$(CONFIG_CPU_SUP_INTEL)            += perf_event_intel_uncore.o
diff --git a/arch/x86/kernel/cpu/perf_event_amd_iommuv2.c 
b/arch/x86/kernel/cpu/perf_event_amd_iommuv2.c
new file mode 100644
index 0000000..7c7b3ff
--- /dev/null
+++ b/arch/x86/kernel/cpu/perf_event_amd_iommuv2.c
@@ -0,0 +1,429 @@
+ /*
+ * Performance events - AMD IOMMUv2
+ *
+ * Copyright (x) 2012 Advanced Micro Devices, Inc., Steven Kinney
+ *
+ * For licensing details see kernel-base/COPYING
+ */
+#include <linux/perf_event.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/ptrace.h>
+
+#include "perf_event.h"
+#include "perf_event_amd_iommuv2.h"
+
+static u64 cntr_assign_mask;
+
+#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_AMD_IOMMU_V2_PC)
+
+/* define iommuv2 states based on ibs, add states if needed */
+enum iommuv2_states {
+       IOMMU_V2_PC_ENABLED     = 0,
+       IOMMU_V2_PC_STARTED     = 1,
+       IOMMU_V2_PC_STOPPING    = 2,
+
+       IOMMU_V2_PC_MAX_STATES,
+};
+
+
+struct cpu_perf_iommuv2 {
+       struct perf_event       *event;
+       unsigned long           state[BITS_TO_LONGS(IOMMU_V2_PC_MAX_STATES)];
+};
+
+
+struct perf_iommuv2 {
+       struct pmu      pmu;
+       struct attribute **format_attrs;
+       struct attribute_group format_group;
+       const struct attribute_group *attr_groups[11];
+       u16             iommuv2_devid;
+       u8              max_banks;
+       u8              max_counters;
+
+       struct cpu_perf_iommuv2  __percpu *pcpu;
+};
+
+
+PMU_FORMAT_ATTR(iommuv2_raw, "config:63");
+PMU_FORMAT_ATTR(csource, "config:7-0");
+PMU_FORMAT_ATTR(deviceid, "config:23-8");
+PMU_FORMAT_ATTR(pasid, "config:39-24");
+PMU_FORMAT_ATTR(domain, "config:55-40");
+PMU_FORMAT_ATTR(en_deviceid_filter, "config:56");
+PMU_FORMAT_ATTR(en_pasid_filter, "config:57");
+PMU_FORMAT_ATTR(en_domain_filter, "config:58");
+PMU_FORMAT_ATTR(deviceid_mask, "config1:15-0");
+PMU_FORMAT_ATTR(pasid_mask, "config1:31-16");
+PMU_FORMAT_ATTR(domain_mask, "config1:47-32");
+
+
+static struct attribute *iommuv2_fetch_format_attrs[] = {
+       &format_attr_iommuv2_raw.attr,
+       &format_attr_csource.attr,
+       &format_attr_deviceid.attr,
+       &format_attr_pasid.attr,
+       &format_attr_domain.attr,
+       &format_attr_en_deviceid_filter.attr,
+       &format_attr_en_pasid_filter.attr,
+       &format_attr_en_domain_filter.attr,
+       &format_attr_deviceid_mask.attr,
+       &format_attr_pasid_mask.attr,
+       &format_attr_domain_mask.attr,
+       NULL,
+};
+
+
+static struct perf_iommuv2 perf_iommuv2_fetch;
+
+
+static u64 read_iommu_v2_pc_icounter(u16 devid, u8 bank, u8 counter)
+{
+       long long val = 0;
+
+       /* modify to calculate pc offsets within this level */
+       amd_iommu_v2_get_set_pc_reg_val(devid,
+                                       bank,
+                                       counter,
+                                       IOMMUV2_PC_COUNTER_REG,
+                                       &val,
+                                       false);
+
+       return val;
+}
+
+
+static u16 get_next_avail_iommuv2_bnk_cntr(struct perf_iommuv2 *perf_iommuv2)
+{
+       int bank_index, cntr_index;
+       int max_banks, max_cntrs;
+       int shift = 0;
+       int bank_offset = 0;
+       u16 retval;
+
+       max_banks = perf_iommuv2->max_banks;
+       max_cntrs = perf_iommuv2->max_counters;
+
+       for (bank_index = 0; bank_index < max_banks; bank_index++) {
+               for (cntr_index = 0; cntr_index < max_cntrs; cntr_index++) {
+                       shift = bank_index + cntr_index + bank_offset;
+                       if (cntr_assign_mask & (1ULL<<shift))
+                               continue;
+                       else {
+                               cntr_assign_mask |= (1ULL<<shift);
+                               retval = ((u16)((u16)bank_index<<8) |
+                                         (u8)(cntr_index));
+                               goto out;
+                       }
+               }
+               bank_offset += 3;
+       }
+       retval = -EINVAL;
+out:
+       return retval;
+}
+
+
+static int clear_avail_iommuv2_bnk_cntr(struct perf_iommuv2 *perf_iommuv2,
+                                       u8 bank,
+                                       u8 cntr)
+{
+       int max_banks, max_cntrs;
+       int shift = 0;
+
+       max_banks = perf_iommuv2->max_banks;
+       max_cntrs = perf_iommuv2->max_counters;
+
+       if ((bank > max_banks) || (cntr > max_cntrs))
+               return -EINVAL;
+
+       shift = bank + cntr + (bank*3);
+       cntr_assign_mask &= ~(1ULL<<shift);
+
+       return 0;
+}
+
+
+static int perf_iommuv2_init(struct perf_event *event)
+{
+       struct hw_perf_event *hwc = &event->hw;
+       struct perf_iommuv2 *perf_iommuv2;
+       u64 config, config1;
+
+       /* initialize the cntr_assign_mask */
+       cntr_assign_mask = 0;
+
+       /* test the event attr type check for PMU enumeration */
+       if (event->attr.type != event->pmu->type)
+               return -ENOENT;
+
+       perf_iommuv2 = &perf_iommuv2_fetch;
+
+       if (perf_iommuv2) {
+               config = event->attr.config;
+               config1 = event->attr.config1;
+       } else
+               return -EINVAL;
+
+       if (event->pmu != &perf_iommuv2->pmu)
+               return -ENOENT;
+
+       /* make sure the event->attr.config is raw (vendor specific) */
+       if (!(config & IOMMU_V2_PC_RAW_CONFIG_MASK))
+               return -EINVAL;
+
+       /* integrate with iommu base devid (0000), assume one iommu */
+       perf_iommuv2->max_banks =
+               amd_iommu_v2_get_max_pc_banks(IOMMU_V2_BASE_DEVID);
+       perf_iommuv2->max_counters =
+               amd_iommu_v2_get_max_pc_counters(IOMMU_V2_BASE_DEVID);
+
+       /* update the hw_perf_event struct with the iommuv2 config data */
+       hwc->config = config;
+       hwc->extra_reg.config = config1;
+
+       return 0;
+}
+
+
+static void perf_iommuv2_event_update(struct perf_event *event, u64 *config,
+                                     u16 *bank_cntr)
+{
+       u64 count;
+       u16 devid;
+       u8  bank, cntr;
+       u64 prev_raw_count;
+       u64 delta;
+       struct hw_perf_event *hwc = &event->hw;
+
+       devid = (u16)(*config & IOMMU_V2_PC_DEVICEID_MATCH)>>8;
+       bank  = (u8)*bank_cntr >> 8;
+       cntr  = (u8)*bank_cntr;
+
+       count = read_iommu_v2_pc_icounter(devid, bank, cntr);
+
+       prev_raw_count =  local64_read(&hwc->prev_count);
+       if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
+                                       count) != prev_raw_count)
+               return;
+
+       delta = count - prev_raw_count;
+       local64_add(delta, &event->count);
+
+}
+
+
+static void perf_iommuv2_enable_event(struct hw_perf_event *hwc)
+{
+       u16 devid;
+       u8  bank, cntr, csource;
+       long long val;
+
+       devid   = (u16)(hwc->config & IOMMU_V2_PC_DEVICEID_MATCH)>>8;
+       bank    = (u8)hwc->extra_reg.reg >> 8;
+       cntr    = (u8)hwc->extra_reg.reg;
+       csource = (u8)(hwc->config & IOMMU_V2_PC_CSOURCE);
+
+       val = csource;
+
+       amd_iommu_v2_get_set_pc_reg_val(devid,
+                                        bank,
+                                        cntr,
+                                        IOMMUV2_PC_COUNTER_SRC_REG,
+                                        &val,
+                                        true);
+}
+
+
+static void perf_iommuv2_disable_event(struct hw_perf_event *hwc)
+{
+       u16 devid;
+       u8  bank, cntr;
+       long long val;
+
+       devid = (u16)(hwc->config & IOMMU_V2_PC_DEVICEID_MATCH)>>8;
+       bank  = (u8)hwc->extra_reg.reg>>8;
+       cntr  = (u8)hwc->extra_reg.reg;
+
+       val = PC_CSOURCE_DISABLE_CNT;
+
+       amd_iommu_v2_get_set_pc_reg_val(devid,
+                                        bank,
+                                        cntr,
+                                        IOMMUV2_PC_COUNTER_SRC_REG,
+                                        &val,
+                                        true);
+}
+
+
+static void perf_iommuv2_start(struct perf_event *event, int flags)
+{
+       struct hw_perf_event *hwc = &event->hw;
+       struct perf_iommuv2 *perf_iommuv2 =
+                       container_of(event->pmu, struct perf_iommuv2, pmu);
+       struct cpu_perf_iommuv2 *pcpu = this_cpu_ptr(perf_iommuv2->pcpu);
+
+       if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
+               return;
+
+       WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+       hwc->state = 0;
+
+       set_bit(IOMMU_V2_PC_STARTED, pcpu->state);
+       perf_iommuv2_enable_event(hwc);
+       perf_event_update_userpage(event);
+}
+
+
+static void perf_iommuv2_stop(struct perf_event *event, int flags)
+{
+       struct hw_perf_event *hwc = &event->hw;
+       struct perf_iommuv2 *perf_iommuv2 =
+                       container_of(event->pmu, struct perf_iommuv2, pmu);
+       struct cpu_perf_iommuv2 *pcpu = this_cpu_ptr(perf_iommuv2->pcpu);
+       int stopping;
+       u16 bank_cntr;
+       u64 config;
+
+       stopping = test_and_clear_bit(IOMMU_V2_PC_STARTED, pcpu->state);
+
+       if (!stopping && (hwc->state & PERF_HES_UPTODATE))
+               return;
+
+       if (stopping) {
+               set_bit(IOMMU_V2_PC_STOPPING, pcpu->state);
+               perf_iommuv2_disable_event(hwc);
+               WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
+               hwc->state |= PERF_HES_STOPPED;
+       }
+
+       if (hwc->state & PERF_HES_UPTODATE)
+               return;
+
+       config = hwc->config;
+       bank_cntr = (u16)hwc->extra_reg.reg;
+       perf_iommuv2_event_update(event, &config, &bank_cntr);
+       hwc->state |= PERF_HES_UPTODATE;
+}
+
+
+static int perf_iommuv2_add(struct perf_event *event, int flags)
+{
+       struct perf_iommuv2 *perf_iommuv2 =
+                       container_of(event->pmu, struct perf_iommuv2, pmu);
+       struct cpu_perf_iommuv2 *pcpu = this_cpu_ptr(perf_iommuv2->pcpu);
+       u16 bank_cntr;
+
+       if (test_and_set_bit(IOMMU_V2_PC_ENABLED, pcpu->state))
+               return -ENOSPC;
+
+       event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+
+       pcpu->event = event;
+
+       /* request an iommuv2 bank/counter */
+       bank_cntr = get_next_avail_iommuv2_bnk_cntr(perf_iommuv2);
+       event->hw.extra_reg.reg = bank_cntr;
+
+       if (flags & PERF_EF_START)
+               perf_iommuv2_start(event, PERF_EF_RELOAD);
+
+       return 0;
+}
+
+
+static void perf_iommuv2_del(struct perf_event *event, int flags)
+{
+       struct perf_iommuv2 *perf_iommuv2 =
+                       container_of(event->pmu, struct perf_iommuv2, pmu);
+       struct cpu_perf_iommuv2 *pcpu = this_cpu_ptr(perf_iommuv2->pcpu);
+       u8 bank, cntr;
+
+       if (!test_and_clear_bit(IOMMU_V2_PC_ENABLED, pcpu->state))
+               return;
+
+       perf_iommuv2_stop(event, PERF_EF_UPDATE);
+
+       /* clear the assigned iommuv2 bank/counter */
+       bank = (u8)event->hw.extra_reg.reg >> 8;
+       cntr = (u8)event->hw.extra_reg.reg;
+       clear_avail_iommuv2_bnk_cntr(perf_iommuv2,
+                                    bank,
+                                    cntr);
+       pcpu->event = NULL;
+
+       perf_event_update_userpage(event);
+}
+
+
+static void perf_iommuv2_read(struct perf_event *event)
+{
+       pr_debug("AMD IOMMUv2: perf_iommuv2_read called\n");
+}
+
+
+static struct perf_iommuv2 perf_iommuv2_fetch = {
+       .pmu = {
+               .event_init     = perf_iommuv2_init,
+               .add            = perf_iommuv2_add,
+               .del            = perf_iommuv2_del,
+               .start          = perf_iommuv2_start,
+               .stop           = perf_iommuv2_stop,
+               .read           = perf_iommuv2_read,
+       },
+       .format_attrs           = iommuv2_fetch_format_attrs,
+       .max_banks              = 0x00,
+       .max_counters           = 0x00,
+};
+
+
+static __init int perf_iommuv2_pmu_init(struct perf_iommuv2 *perf_iommuv2,
+                                       char *name)
+{
+       struct cpu_perf_iommuv2 __percpu *pcpu;
+       int ret;
+
+       pcpu = alloc_percpu(struct cpu_perf_iommuv2);
+       if (!pcpu)
+               return -ENOMEM;
+
+       perf_iommuv2->pcpu = pcpu;
+
+       /* allocate and register atttributes */
+       if (perf_iommuv2->format_attrs[0]) {
+               memset(&perf_iommuv2->format_group, 0,
+                       sizeof(perf_iommuv2->format_group));
+               perf_iommuv2->format_group.name = "format";
+               perf_iommuv2->format_group.attrs = perf_iommuv2->format_attrs;
+               memset(&perf_iommuv2->attr_groups, 0,
+                       sizeof(perf_iommuv2->attr_groups));
+               perf_iommuv2->attr_groups[0] = &perf_iommuv2->format_group;
+               perf_iommuv2->pmu.attr_groups = perf_iommuv2->attr_groups;
+       }
+
+       ret = perf_pmu_register(&perf_iommuv2->pmu, name, -1);
+       if (ret) {
+               pr_info("AMD IOMMUv2 PMU - ERROR Registering IOMMUv2 Perf 
PMU\n");
+               perf_iommuv2->pcpu = NULL;
+               free_percpu(pcpu);
+       }
+
+       return ret;
+}
+
+static __init int amd_iommuv2_init(void)
+{
+       /* Make sure the IOMMUv2 PC resource is available */
+       if (!amd_iommu_v2_pc_supported()) {
+               pr_info("Perf IOMMUv2 - PMU not installed no support!\n");
+               return -ENODEV;
+       }
+
+       perf_iommuv2_pmu_init(&perf_iommuv2_fetch, "iommuv2");
+
+       return 0;
+}
+
+device_initcall(amd_iommuv2_init);
+#endif
diff --git a/arch/x86/kernel/cpu/perf_event_amd_iommuv2.h 
b/arch/x86/kernel/cpu/perf_event_amd_iommuv2.h
new file mode 100644
index 0000000..10d341e
--- /dev/null
+++ b/arch/x86/kernel/cpu/perf_event_amd_iommuv2.h
@@ -0,0 +1,42 @@
+
+/* iommuv2 pc mmio region register indexes */
+#define IOMMUV2_PC_COUNTER_REG                 0x00
+#define IOMMUV2_PC_COUNTER_SRC_REG             0x08
+#define IOMMUV2_PC_PASID_MATCH_REG             0x10
+#define IOMMUV2_PC_DOMAIN_MATCH_REG            0x18
+#define IOMMUV2_PC_DEVICEID_MATCH_REG          0x20
+#define IOMMUV2_PC_COUNTER_REPORT_REG          0x28
+
+/* iommuv2 pc csource register values */
+#define PC_CSOURCE_DISABLE_CNT                 0x00
+
+/* maximun specified bank/counters */
+#define PC_MAX_SPEC_BNKS                       64
+#define PC_MAX_SPEC_CNTRS                      16
+
+/* iommuv2 pmu config masks */
+#define IOMMU_V2_PC_RAW_CONFIG_MASK            (1ULL << 63)
+#define IOMMU_V2_PC_CSOURCE                    (0xFFULL << 0)
+#define IOMMU_V2_PC_DEVICEID_MATCH             (0xFFFFULL << 8)
+#define IOMMU_V2_PC_PASID_MATCH                        (0xFFFFULL << 24)
+#define IOMMU_V2_PC_DOMAIN_MATCH               (0xFFFFULL << 40)
+#define IOMMU_V2_PC_EN_DEVICEID                        (1ULL << 56)
+#define IOMMU_V2_PC_EN_PASID                   (1ULL << 57)
+#define IOMMU_V2_PC_EN_DOMAIN                  (1ULL << 58)
+#define IOMMU_V2_PC_DEVICEID_MASK              (0xFFFFULL << 0)
+#define IOMMU_V2_PC_PASID_MASK                 (0xFFFFULL << 16)
+#define IOMMU_V2_PC_DOMAIN_MASK                        (0xFFFFULL << 32)
+
+#define IOMMU_V2_BASE_DEVID                    0x0000
+
+/* amd_iommu_init.c external support functions */
+extern bool amd_iommu_v2_pc_supported(void);
+extern u8 amd_iommu_v2_get_max_pc_banks(u16 devid);
+extern u8 amd_iommu_v2_get_max_pc_counters(u16 devid);
+extern int amd_iommu_v2_get_set_pc_reg_val(
+                                       u16 devid,
+                                       u8 bank,
+                                       u8 cntr,
+                                       u8 fxn,
+                                       long long *value,
+                                       bool is_write);
-- 
1.7.9.5


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