diff options
Diffstat (limited to 'drivers/perf/apple_m1_cpu_pmu.c')
| -rw-r--r-- | drivers/perf/apple_m1_cpu_pmu.c | 584 |
1 files changed, 584 insertions, 0 deletions
diff --git a/drivers/perf/apple_m1_cpu_pmu.c b/drivers/perf/apple_m1_cpu_pmu.c new file mode 100644 index 000000000..979a7c2b4 --- /dev/null +++ b/drivers/perf/apple_m1_cpu_pmu.c @@ -0,0 +1,584 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CPU PMU driver for the Apple M1 and derivatives + * + * Copyright (C) 2021 Google LLC + * + * Author: Marc Zyngier <maz@kernel.org> + * + * Most of the information used in this driver was provided by the + * Asahi Linux project. The rest was experimentally discovered. + */ + +#include <linux/of.h> +#include <linux/perf/arm_pmu.h> +#include <linux/platform_device.h> + +#include <asm/apple_m1_pmu.h> +#include <asm/irq_regs.h> +#include <asm/perf_event.h> + +#define M1_PMU_NR_COUNTERS 10 + +#define M1_PMU_CFG_EVENT GENMASK(7, 0) + +#define ANY_BUT_0_1 GENMASK(9, 2) +#define ONLY_2_TO_7 GENMASK(7, 2) +#define ONLY_2_4_6 (BIT(2) | BIT(4) | BIT(6)) +#define ONLY_5_6_7 (BIT(5) | BIT(6) | BIT(7)) + +/* + * Description of the events we actually know about, as well as those with + * a specific counter affinity. Yes, this is a grand total of two known + * counters, and the rest is anybody's guess. + * + * Not all counters can count all events. Counters #0 and #1 are wired to + * count cycles and instructions respectively, and some events have + * bizarre mappings (every other counter, or even *one* counter). These + * restrictions equally apply to both P and E cores. + * + * It is worth noting that the PMUs attached to P and E cores are likely + * to be different because the underlying uarches are different. At the + * moment, we don't really need to distinguish between the two because we + * know next to nothing about the events themselves, and we already have + * per cpu-type PMU abstractions. + * + * If we eventually find out that the events are different across + * implementations, we'll have to introduce per cpu-type tables. + */ +enum m1_pmu_events { + M1_PMU_PERFCTR_UNKNOWN_01 = 0x01, + M1_PMU_PERFCTR_CPU_CYCLES = 0x02, + M1_PMU_PERFCTR_INSTRUCTIONS = 0x8c, + M1_PMU_PERFCTR_UNKNOWN_8d = 0x8d, + M1_PMU_PERFCTR_UNKNOWN_8e = 0x8e, + M1_PMU_PERFCTR_UNKNOWN_8f = 0x8f, + M1_PMU_PERFCTR_UNKNOWN_90 = 0x90, + M1_PMU_PERFCTR_UNKNOWN_93 = 0x93, + M1_PMU_PERFCTR_UNKNOWN_94 = 0x94, + M1_PMU_PERFCTR_UNKNOWN_95 = 0x95, + M1_PMU_PERFCTR_UNKNOWN_96 = 0x96, + M1_PMU_PERFCTR_UNKNOWN_97 = 0x97, + M1_PMU_PERFCTR_UNKNOWN_98 = 0x98, + M1_PMU_PERFCTR_UNKNOWN_99 = 0x99, + M1_PMU_PERFCTR_UNKNOWN_9a = 0x9a, + M1_PMU_PERFCTR_UNKNOWN_9b = 0x9b, + M1_PMU_PERFCTR_UNKNOWN_9c = 0x9c, + M1_PMU_PERFCTR_UNKNOWN_9f = 0x9f, + M1_PMU_PERFCTR_UNKNOWN_bf = 0xbf, + M1_PMU_PERFCTR_UNKNOWN_c0 = 0xc0, + M1_PMU_PERFCTR_UNKNOWN_c1 = 0xc1, + M1_PMU_PERFCTR_UNKNOWN_c4 = 0xc4, + M1_PMU_PERFCTR_UNKNOWN_c5 = 0xc5, + M1_PMU_PERFCTR_UNKNOWN_c6 = 0xc6, + M1_PMU_PERFCTR_UNKNOWN_c8 = 0xc8, + M1_PMU_PERFCTR_UNKNOWN_ca = 0xca, + M1_PMU_PERFCTR_UNKNOWN_cb = 0xcb, + M1_PMU_PERFCTR_UNKNOWN_f5 = 0xf5, + M1_PMU_PERFCTR_UNKNOWN_f6 = 0xf6, + M1_PMU_PERFCTR_UNKNOWN_f7 = 0xf7, + M1_PMU_PERFCTR_UNKNOWN_f8 = 0xf8, + M1_PMU_PERFCTR_UNKNOWN_fd = 0xfd, + M1_PMU_PERFCTR_LAST = M1_PMU_CFG_EVENT, + + /* + * From this point onwards, these are not actual HW events, + * but attributes that get stored in hw->config_base. + */ + M1_PMU_CFG_COUNT_USER = BIT(8), + M1_PMU_CFG_COUNT_KERNEL = BIT(9), +}; + +/* + * Per-event affinity table. Most events can be installed on counter + * 2-9, but there are a number of exceptions. Note that this table + * has been created experimentally, and I wouldn't be surprised if more + * counters had strange affinities. + */ +static const u16 m1_pmu_event_affinity[M1_PMU_PERFCTR_LAST + 1] = { + [0 ... M1_PMU_PERFCTR_LAST] = ANY_BUT_0_1, + [M1_PMU_PERFCTR_UNKNOWN_01] = BIT(7), + [M1_PMU_PERFCTR_CPU_CYCLES] = ANY_BUT_0_1 | BIT(0), + [M1_PMU_PERFCTR_INSTRUCTIONS] = BIT(7) | BIT(1), + [M1_PMU_PERFCTR_UNKNOWN_8d] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_8e] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_8f] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_90] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_93] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_94] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_95] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_96] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_97] = BIT(7), + [M1_PMU_PERFCTR_UNKNOWN_98] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_99] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_9a] = BIT(7), + [M1_PMU_PERFCTR_UNKNOWN_9b] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_9c] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_9f] = BIT(7), + [M1_PMU_PERFCTR_UNKNOWN_bf] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_c0] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_c1] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_c4] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_c5] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_c6] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_c8] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_ca] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_cb] = ONLY_5_6_7, + [M1_PMU_PERFCTR_UNKNOWN_f5] = ONLY_2_4_6, + [M1_PMU_PERFCTR_UNKNOWN_f6] = ONLY_2_4_6, + [M1_PMU_PERFCTR_UNKNOWN_f7] = ONLY_2_4_6, + [M1_PMU_PERFCTR_UNKNOWN_f8] = ONLY_2_TO_7, + [M1_PMU_PERFCTR_UNKNOWN_fd] = ONLY_2_4_6, +}; + +static const unsigned m1_pmu_perf_map[PERF_COUNT_HW_MAX] = { + PERF_MAP_ALL_UNSUPPORTED, + [PERF_COUNT_HW_CPU_CYCLES] = M1_PMU_PERFCTR_CPU_CYCLES, + [PERF_COUNT_HW_INSTRUCTIONS] = M1_PMU_PERFCTR_INSTRUCTIONS, + /* No idea about the rest yet */ +}; + +/* sysfs definitions */ +static ssize_t m1_pmu_events_sysfs_show(struct device *dev, + struct device_attribute *attr, + char *page) +{ + struct perf_pmu_events_attr *pmu_attr; + + pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr); + + return sprintf(page, "event=0x%04llx\n", pmu_attr->id); +} + +#define M1_PMU_EVENT_ATTR(name, config) \ + PMU_EVENT_ATTR_ID(name, m1_pmu_events_sysfs_show, config) + +static struct attribute *m1_pmu_event_attrs[] = { + M1_PMU_EVENT_ATTR(cycles, M1_PMU_PERFCTR_CPU_CYCLES), + M1_PMU_EVENT_ATTR(instructions, M1_PMU_PERFCTR_INSTRUCTIONS), + NULL, +}; + +static const struct attribute_group m1_pmu_events_attr_group = { + .name = "events", + .attrs = m1_pmu_event_attrs, +}; + +PMU_FORMAT_ATTR(event, "config:0-7"); + +static struct attribute *m1_pmu_format_attrs[] = { + &format_attr_event.attr, + NULL, +}; + +static const struct attribute_group m1_pmu_format_attr_group = { + .name = "format", + .attrs = m1_pmu_format_attrs, +}; + +/* Low level accessors. No synchronisation. */ +#define PMU_READ_COUNTER(_idx) \ + case _idx: return read_sysreg_s(SYS_IMP_APL_PMC## _idx ##_EL1) + +#define PMU_WRITE_COUNTER(_val, _idx) \ + case _idx: \ + write_sysreg_s(_val, SYS_IMP_APL_PMC## _idx ##_EL1); \ + return + +static u64 m1_pmu_read_hw_counter(unsigned int index) +{ + switch (index) { + PMU_READ_COUNTER(0); + PMU_READ_COUNTER(1); + PMU_READ_COUNTER(2); + PMU_READ_COUNTER(3); + PMU_READ_COUNTER(4); + PMU_READ_COUNTER(5); + PMU_READ_COUNTER(6); + PMU_READ_COUNTER(7); + PMU_READ_COUNTER(8); + PMU_READ_COUNTER(9); + } + + BUG(); +} + +static void m1_pmu_write_hw_counter(u64 val, unsigned int index) +{ + switch (index) { + PMU_WRITE_COUNTER(val, 0); + PMU_WRITE_COUNTER(val, 1); + PMU_WRITE_COUNTER(val, 2); + PMU_WRITE_COUNTER(val, 3); + PMU_WRITE_COUNTER(val, 4); + PMU_WRITE_COUNTER(val, 5); + PMU_WRITE_COUNTER(val, 6); + PMU_WRITE_COUNTER(val, 7); + PMU_WRITE_COUNTER(val, 8); + PMU_WRITE_COUNTER(val, 9); + } + + BUG(); +} + +#define get_bit_offset(index, mask) (__ffs(mask) + (index)) + +static void __m1_pmu_enable_counter(unsigned int index, bool en) +{ + u64 val, bit; + + switch (index) { + case 0 ... 7: + bit = BIT(get_bit_offset(index, PMCR0_CNT_ENABLE_0_7)); + break; + case 8 ... 9: + bit = BIT(get_bit_offset(index - 8, PMCR0_CNT_ENABLE_8_9)); + break; + default: + BUG(); + } + + val = read_sysreg_s(SYS_IMP_APL_PMCR0_EL1); + + if (en) + val |= bit; + else + val &= ~bit; + + write_sysreg_s(val, SYS_IMP_APL_PMCR0_EL1); +} + +static void m1_pmu_enable_counter(unsigned int index) +{ + __m1_pmu_enable_counter(index, true); +} + +static void m1_pmu_disable_counter(unsigned int index) +{ + __m1_pmu_enable_counter(index, false); +} + +static void __m1_pmu_enable_counter_interrupt(unsigned int index, bool en) +{ + u64 val, bit; + + switch (index) { + case 0 ... 7: + bit = BIT(get_bit_offset(index, PMCR0_PMI_ENABLE_0_7)); + break; + case 8 ... 9: + bit = BIT(get_bit_offset(index - 8, PMCR0_PMI_ENABLE_8_9)); + break; + default: + BUG(); + } + + val = read_sysreg_s(SYS_IMP_APL_PMCR0_EL1); + + if (en) + val |= bit; + else + val &= ~bit; + + write_sysreg_s(val, SYS_IMP_APL_PMCR0_EL1); +} + +static void m1_pmu_enable_counter_interrupt(unsigned int index) +{ + __m1_pmu_enable_counter_interrupt(index, true); +} + +static void m1_pmu_disable_counter_interrupt(unsigned int index) +{ + __m1_pmu_enable_counter_interrupt(index, false); +} + +static void m1_pmu_configure_counter(unsigned int index, u8 event, + bool user, bool kernel) +{ + u64 val, user_bit, kernel_bit; + int shift; + + switch (index) { + case 0 ... 7: + user_bit = BIT(get_bit_offset(index, PMCR1_COUNT_A64_EL0_0_7)); + kernel_bit = BIT(get_bit_offset(index, PMCR1_COUNT_A64_EL1_0_7)); + break; + case 8 ... 9: + user_bit = BIT(get_bit_offset(index - 8, PMCR1_COUNT_A64_EL0_8_9)); + kernel_bit = BIT(get_bit_offset(index - 8, PMCR1_COUNT_A64_EL1_8_9)); + break; + default: + BUG(); + } + + val = read_sysreg_s(SYS_IMP_APL_PMCR1_EL1); + + if (user) + val |= user_bit; + else + val &= ~user_bit; + + if (kernel) + val |= kernel_bit; + else + val &= ~kernel_bit; + + write_sysreg_s(val, SYS_IMP_APL_PMCR1_EL1); + + /* + * Counters 0 and 1 have fixed events. For anything else, + * place the event at the expected location in the relevant + * register (PMESR0 holds the event configuration for counters + * 2-5, resp. PMESR1 for counters 6-9). + */ + switch (index) { + case 0 ... 1: + break; + case 2 ... 5: + shift = (index - 2) * 8; + val = read_sysreg_s(SYS_IMP_APL_PMESR0_EL1); + val &= ~((u64)0xff << shift); + val |= (u64)event << shift; + write_sysreg_s(val, SYS_IMP_APL_PMESR0_EL1); + break; + case 6 ... 9: + shift = (index - 6) * 8; + val = read_sysreg_s(SYS_IMP_APL_PMESR1_EL1); + val &= ~((u64)0xff << shift); + val |= (u64)event << shift; + write_sysreg_s(val, SYS_IMP_APL_PMESR1_EL1); + break; + } +} + +/* arm_pmu backend */ +static void m1_pmu_enable_event(struct perf_event *event) +{ + bool user, kernel; + u8 evt; + + evt = event->hw.config_base & M1_PMU_CFG_EVENT; + user = event->hw.config_base & M1_PMU_CFG_COUNT_USER; + kernel = event->hw.config_base & M1_PMU_CFG_COUNT_KERNEL; + + m1_pmu_disable_counter_interrupt(event->hw.idx); + m1_pmu_disable_counter(event->hw.idx); + isb(); + + m1_pmu_configure_counter(event->hw.idx, evt, user, kernel); + m1_pmu_enable_counter(event->hw.idx); + m1_pmu_enable_counter_interrupt(event->hw.idx); + isb(); +} + +static void m1_pmu_disable_event(struct perf_event *event) +{ + m1_pmu_disable_counter_interrupt(event->hw.idx); + m1_pmu_disable_counter(event->hw.idx); + isb(); +} + +static irqreturn_t m1_pmu_handle_irq(struct arm_pmu *cpu_pmu) +{ + struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events); + struct pt_regs *regs; + u64 overflow, state; + int idx; + + overflow = read_sysreg_s(SYS_IMP_APL_PMSR_EL1); + if (!overflow) { + /* Spurious interrupt? */ + state = read_sysreg_s(SYS_IMP_APL_PMCR0_EL1); + state &= ~PMCR0_IACT; + write_sysreg_s(state, SYS_IMP_APL_PMCR0_EL1); + isb(); + return IRQ_NONE; + } + + cpu_pmu->stop(cpu_pmu); + + regs = get_irq_regs(); + + for (idx = 0; idx < cpu_pmu->num_events; idx++) { + struct perf_event *event = cpuc->events[idx]; + struct perf_sample_data data; + + if (!event) + continue; + + armpmu_event_update(event); + perf_sample_data_init(&data, 0, event->hw.last_period); + if (!armpmu_event_set_period(event)) + continue; + + if (perf_event_overflow(event, &data, regs)) + m1_pmu_disable_event(event); + } + + cpu_pmu->start(cpu_pmu); + + return IRQ_HANDLED; +} + +static u64 m1_pmu_read_counter(struct perf_event *event) +{ + return m1_pmu_read_hw_counter(event->hw.idx); +} + +static void m1_pmu_write_counter(struct perf_event *event, u64 value) +{ + m1_pmu_write_hw_counter(value, event->hw.idx); + isb(); +} + +static int m1_pmu_get_event_idx(struct pmu_hw_events *cpuc, + struct perf_event *event) +{ + unsigned long evtype = event->hw.config_base & M1_PMU_CFG_EVENT; + unsigned long affinity = m1_pmu_event_affinity[evtype]; + int idx; + + /* + * Place the event on the first free counter that can count + * this event. + * + * We could do a better job if we had a view of all the events + * counting on the PMU at any given time, and by placing the + * most constraining events first. + */ + for_each_set_bit(idx, &affinity, M1_PMU_NR_COUNTERS) { + if (!test_and_set_bit(idx, cpuc->used_mask)) + return idx; + } + + return -EAGAIN; +} + +static void m1_pmu_clear_event_idx(struct pmu_hw_events *cpuc, + struct perf_event *event) +{ + clear_bit(event->hw.idx, cpuc->used_mask); +} + +static void __m1_pmu_set_mode(u8 mode) +{ + u64 val; + + val = read_sysreg_s(SYS_IMP_APL_PMCR0_EL1); + val &= ~(PMCR0_IMODE | PMCR0_IACT); + val |= FIELD_PREP(PMCR0_IMODE, mode); + write_sysreg_s(val, SYS_IMP_APL_PMCR0_EL1); + isb(); +} + +static void m1_pmu_start(struct arm_pmu *cpu_pmu) +{ + __m1_pmu_set_mode(PMCR0_IMODE_FIQ); +} + +static void m1_pmu_stop(struct arm_pmu *cpu_pmu) +{ + __m1_pmu_set_mode(PMCR0_IMODE_OFF); +} + +static int m1_pmu_map_event(struct perf_event *event) +{ + /* + * Although the counters are 48bit wide, bit 47 is what + * triggers the overflow interrupt. Advertise the counters + * being 47bit wide to mimick the behaviour of the ARM PMU. + */ + event->hw.flags |= ARMPMU_EVT_47BIT; + return armpmu_map_event(event, &m1_pmu_perf_map, NULL, M1_PMU_CFG_EVENT); +} + +static void m1_pmu_reset(void *info) +{ + int i; + + __m1_pmu_set_mode(PMCR0_IMODE_OFF); + + for (i = 0; i < M1_PMU_NR_COUNTERS; i++) { + m1_pmu_disable_counter(i); + m1_pmu_disable_counter_interrupt(i); + m1_pmu_write_hw_counter(0, i); + } + + isb(); +} + +static int m1_pmu_set_event_filter(struct hw_perf_event *event, + struct perf_event_attr *attr) +{ + unsigned long config_base = 0; + + if (!attr->exclude_guest) + return -EINVAL; + if (!attr->exclude_kernel) + config_base |= M1_PMU_CFG_COUNT_KERNEL; + if (!attr->exclude_user) + config_base |= M1_PMU_CFG_COUNT_USER; + + event->config_base = config_base; + + return 0; +} + +static int m1_pmu_init(struct arm_pmu *cpu_pmu) +{ + cpu_pmu->handle_irq = m1_pmu_handle_irq; + cpu_pmu->enable = m1_pmu_enable_event; + cpu_pmu->disable = m1_pmu_disable_event; + cpu_pmu->read_counter = m1_pmu_read_counter; + cpu_pmu->write_counter = m1_pmu_write_counter; + cpu_pmu->get_event_idx = m1_pmu_get_event_idx; + cpu_pmu->clear_event_idx = m1_pmu_clear_event_idx; + cpu_pmu->start = m1_pmu_start; + cpu_pmu->stop = m1_pmu_stop; + cpu_pmu->map_event = m1_pmu_map_event; + cpu_pmu->reset = m1_pmu_reset; + cpu_pmu->set_event_filter = m1_pmu_set_event_filter; + + cpu_pmu->num_events = M1_PMU_NR_COUNTERS; + cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_EVENTS] = &m1_pmu_events_attr_group; + cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_FORMATS] = &m1_pmu_format_attr_group; + return 0; +} + +/* Device driver gunk */ +static int m1_pmu_ice_init(struct arm_pmu *cpu_pmu) +{ + cpu_pmu->name = "apple_icestorm_pmu"; + return m1_pmu_init(cpu_pmu); +} + +static int m1_pmu_fire_init(struct arm_pmu *cpu_pmu) +{ + cpu_pmu->name = "apple_firestorm_pmu"; + return m1_pmu_init(cpu_pmu); +} + +static const struct of_device_id m1_pmu_of_device_ids[] = { + { .compatible = "apple,icestorm-pmu", .data = m1_pmu_ice_init, }, + { .compatible = "apple,firestorm-pmu", .data = m1_pmu_fire_init, }, + { }, +}; +MODULE_DEVICE_TABLE(of, m1_pmu_of_device_ids); + +static int m1_pmu_device_probe(struct platform_device *pdev) +{ + return arm_pmu_device_probe(pdev, m1_pmu_of_device_ids, NULL); +} + +static struct platform_driver m1_pmu_driver = { + .driver = { + .name = "apple-m1-cpu-pmu", + .of_match_table = m1_pmu_of_device_ids, + .suppress_bind_attrs = true, + }, + .probe = m1_pmu_device_probe, +}; + +module_platform_driver(m1_pmu_driver); +MODULE_LICENSE("GPL v2"); |