From: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com> Add multi-IOMMU support for perf by exposing an AMD IOMMU PMU for each IOMMU found in the system via:
/bus/event_source/devices/amd_iommu_x where x is the IOMMU index. This allows users to specify different events to be programmed onto performance counters of each IOMMU. Cc: Borislav Petkov <b...@alien8.de> Cc: Peter Zijlstra <pet...@infradead.org> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com> --- arch/x86/events/amd/iommu.c | 129 ++++++++++++++++++++++++-------------------- 1 file changed, 72 insertions(+), 57 deletions(-) diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c index 7bbf405..cc1d2eb 100644 --- a/arch/x86/events/amd/iommu.c +++ b/arch/x86/events/amd/iommu.c @@ -35,16 +35,21 @@ #define _GET_PASID_MASK(ev) ((ev->hw.extra_reg.config >> 16) & 0xFFFFULL) #define _GET_DOMID_MASK(ev) ((ev->hw.extra_reg.config >> 32) & 0xFFFFULL) -static struct perf_amd_iommu __perf_iommu; +#define PERF_AMD_IOMMU_NAME_SIZE 16 struct perf_amd_iommu { + struct list_head list; struct pmu pmu; + struct amd_iommu *iommu; + char name[PERF_AMD_IOMMU_NAME_SIZE]; u8 max_banks; u8 max_counters; u64 cntr_assign_mask; raw_spinlock_t lock; }; +static LIST_HEAD(perf_amd_iommu_list); + /*--------------------------------------------- * sysfs format attributes *---------------------------------------------*/ @@ -202,8 +207,6 @@ static int clear_avail_iommu_bnk_cntr(struct perf_amd_iommu *perf_iommu, static int perf_iommu_event_init(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; - struct perf_amd_iommu *perf_iommu; - u64 config, config1; /* test the event attr type check for PMU enumeration */ if (event->attr.type != event->pmu->type) @@ -225,28 +228,21 @@ static int perf_iommu_event_init(struct perf_event *event) if (event->cpu < 0) return -EINVAL; - perf_iommu = &__perf_iommu; - - if (event->pmu != &perf_iommu->pmu) - return -ENOENT; - - if (perf_iommu) { - config = event->attr.config; - config1 = event->attr.config1; - } else { - return -EINVAL; - } - /* update the hw_perf_event struct with the iommu config data */ - hwc->config = config; - hwc->extra_reg.config = config1; + hwc->config = event->attr.config; + hwc->extra_reg.config = event->attr.config1; return 0; } +static inline struct amd_iommu *perf_event_2_iommu(struct perf_event *ev) +{ + return (container_of(ev->pmu, struct perf_amd_iommu, pmu))->iommu; +} + static void perf_iommu_enable_event(struct perf_event *ev) { - struct amd_iommu *iommu = get_amd_iommu(0); + struct amd_iommu *iommu = perf_event_2_iommu(ev); u8 csource = _GET_CSOURCE(ev); u16 devid = _GET_DEVID(ev); u8 bank = _GET_BANK(ev); @@ -274,7 +270,7 @@ static void perf_iommu_enable_event(struct perf_event *ev) static void perf_iommu_disable_event(struct perf_event *event) { - struct amd_iommu *iommu = get_amd_iommu(0); + struct amd_iommu *iommu = perf_event_2_iommu(event); u64 reg = 0ULL; amd_iommu_pc_set_reg(iommu, _GET_BANK(event), _GET_CNTR(event), @@ -284,7 +280,7 @@ static void perf_iommu_disable_event(struct perf_event *event) static void perf_iommu_start(struct perf_event *event, int flags) { struct hw_perf_event *hwc = &event->hw; - struct amd_iommu *iommu = get_amd_iommu(0); + struct amd_iommu *iommu = perf_event_2_iommu(event); if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED))) return; @@ -307,7 +303,7 @@ static void perf_iommu_read(struct perf_event *event) { u64 count, prev, delta; struct hw_perf_event *hwc = &event->hw; - struct amd_iommu *iommu = get_amd_iommu(0); + struct amd_iommu *iommu = perf_event_2_iommu(event); if (amd_iommu_pc_get_reg(iommu, _GET_BANK(event), _GET_CNTR(event), IOMMU_PC_COUNTER_REG, &count)) @@ -401,11 +397,6 @@ static __init int _init_events_attrs(void) return 0; } -static __init void amd_iommu_pc_exit(void) -{ - kfree(amd_iommu_events_group.attrs); -} - const struct attribute_group *amd_iommu_attr_groups[] = { &amd_iommu_format_group, &amd_iommu_cpumask_group, @@ -413,47 +404,56 @@ static __init void amd_iommu_pc_exit(void) NULL, }; +static struct pmu iommu_pmu = { + .event_init = perf_iommu_event_init, + .add = perf_iommu_add, + .del = perf_iommu_del, + .start = perf_iommu_start, + .stop = perf_iommu_stop, + .read = perf_iommu_read, + .task_ctx_nr = perf_invalid_context, + .attr_groups = amd_iommu_attr_groups, +}; + static __init int -_init_perf_amd_iommu(struct perf_amd_iommu *perf_iommu, char *name) +init_one_iommu(unsigned int idx) { int ret; + struct perf_amd_iommu *perf_iommu; - raw_spin_lock_init(&perf_iommu->lock); + perf_iommu = kzalloc(sizeof(struct perf_amd_iommu), GFP_KERNEL); + if (!perf_iommu) + return -ENOMEM; - /* Init cpumask attributes to only core 0 */ - cpumask_set_cpu(0, &iommu_cpumask); + raw_spin_lock_init(&perf_iommu->lock); - perf_iommu->max_banks = amd_iommu_pc_get_max_banks(0); - perf_iommu->max_counters = amd_iommu_pc_get_max_counters(0); - if (!perf_iommu->max_banks || !perf_iommu->max_counters) + perf_iommu->pmu = iommu_pmu; + perf_iommu->iommu = get_amd_iommu(idx); + perf_iommu->max_banks = amd_iommu_pc_get_max_banks(idx); + perf_iommu->max_counters = amd_iommu_pc_get_max_counters(idx); + if (!perf_iommu->iommu || !perf_iommu->max_banks || + !perf_iommu->max_counters) { + kfree(perf_iommu); return -EINVAL; + } - perf_iommu->pmu.attr_groups = amd_iommu_attr_groups; - ret = perf_pmu_register(&perf_iommu->pmu, name, -1); - if (ret) - pr_err("Error initializing AMD IOMMU perf counters.\n"); - else - pr_info("perf: amd_iommu: Detected. (%d banks, %d counters/bank)\n", - amd_iommu_pc_get_max_banks(0), - amd_iommu_pc_get_max_counters(0)); + snprintf(perf_iommu->name, PERF_AMD_IOMMU_NAME_SIZE, "amd_iommu_%u", idx); + ret = perf_pmu_register(&perf_iommu->pmu, perf_iommu->name, -1); + if (!ret) { + pr_info("Detected AMD IOMMU #%d (%d banks, %d counters/bank)\n", + idx, perf_iommu->max_banks, perf_iommu->max_counters); + list_add_tail(&perf_iommu->list, &perf_amd_iommu_list); + } else { + pr_warn("Error initializing IOMMU %d.\n", idx); + kfree(perf_iommu); + } return ret; } -static struct perf_amd_iommu __perf_iommu = { - .pmu = { - .task_ctx_nr = perf_invalid_context, - .event_init = perf_iommu_event_init, - .add = perf_iommu_add, - .del = perf_iommu_del, - .start = perf_iommu_start, - .stop = perf_iommu_stop, - .read = perf_iommu_read, - }, -}; - static __init int amd_iommu_pc_init(void) { int ret; + unsigned int i, cnt = 0; /* Make sure the IOMMU PC resource is available */ if (!amd_iommu_pc_supported()) @@ -463,11 +463,26 @@ static __init int amd_iommu_pc_init(void) if (ret) return ret; - ret = _init_perf_amd_iommu(&__perf_iommu, "amd_iommu"); - if (ret) - amd_iommu_pc_exit(); + /* + * An IOMMU PMU is specific to each IOMMU, and can + * function independently. So, we go through all IOMMUs + * and ignore the one that fails initialization unless + * all IOMMU are failing. + */ + for (i = 0; i < amd_iommu_get_num_iommus(); i++) { + ret = init_one_iommu(i); + if (!ret) + cnt++; + } - return ret; + if (!cnt) { + kfree(amd_iommu_events_group.attrs); + return -ENODEV; + } + + /* Init cpumask attributes to only core 0 */ + cpumask_set_cpu(0, &iommu_cpumask); + return 0; } device_initcall(amd_iommu_pc_init); -- 1.8.3.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu