diff options
Diffstat (limited to 'arch/s390/kernel/perf_pai_ext.c')
| -rw-r--r-- | arch/s390/kernel/perf_pai_ext.c | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/arch/s390/kernel/perf_pai_ext.c b/arch/s390/kernel/perf_pai_ext.c new file mode 100644 index 000000000..74b53c531 --- /dev/null +++ b/arch/s390/kernel/perf_pai_ext.c @@ -0,0 +1,672 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Performance event support - Processor Activity Instrumentation Extension + * Facility + * + * Copyright IBM Corp. 2022 + * Author(s): Thomas Richter <tmricht@linux.ibm.com> + */ +#define KMSG_COMPONENT "pai_ext" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/kernel.h> +#include <linux/kernel_stat.h> +#include <linux/percpu.h> +#include <linux/notifier.h> +#include <linux/init.h> +#include <linux/export.h> +#include <linux/io.h> + +#include <asm/cpu_mcf.h> +#include <asm/ctl_reg.h> +#include <asm/pai.h> +#include <asm/debug.h> + +#define PAIE1_CB_SZ 0x200 /* Size of PAIE1 control block */ +#define PAIE1_CTRBLOCK_SZ 0x400 /* Size of PAIE1 counter blocks */ + +static debug_info_t *paiext_dbg; +static unsigned int paiext_cnt; /* Extracted with QPACI instruction */ + +enum paiext_mode { + PAI_MODE_NONE, + PAI_MODE_SAMPLING, + PAI_MODE_COUNTER, +}; + +struct pai_userdata { + u16 num; + u64 value; +} __packed; + +/* Create the PAI extension 1 control block area. + * The PAI extension control block 1 is pointed to by lowcore + * address 0x1508 for each CPU. This control block is 512 bytes in size + * and requires a 512 byte boundary alignment. + */ +struct paiext_cb { /* PAI extension 1 control block */ + u64 header; /* Not used */ + u64 reserved1; + u64 acc; /* Addr to analytics counter control block */ + u8 reserved2[488]; +} __packed; + +struct paiext_map { + unsigned long *area; /* Area for CPU to store counters */ + struct pai_userdata *save; /* Area to store non-zero counters */ + enum paiext_mode mode; /* Type of event */ + unsigned int active_events; /* # of PAI Extension users */ + unsigned int refcnt; + struct perf_event *event; /* Perf event for sampling */ + struct paiext_cb *paiext_cb; /* PAI extension control block area */ +}; + +struct paiext_mapptr { + struct paiext_map *mapptr; +}; + +static struct paiext_root { /* Anchor to per CPU data */ + int refcnt; /* Overall active events */ + struct paiext_mapptr __percpu *mapptr; +} paiext_root; + +/* Free per CPU data when the last event is removed. */ +static void paiext_root_free(void) +{ + if (!--paiext_root.refcnt) { + free_percpu(paiext_root.mapptr); + paiext_root.mapptr = NULL; + } +} + +/* On initialization of first event also allocate per CPU data dynamically. + * Start with an array of pointers, the array size is the maximum number of + * CPUs possible, which might be larger than the number of CPUs currently + * online. + */ +static int paiext_root_alloc(void) +{ + if (++paiext_root.refcnt == 1) { + /* The memory is already zeroed. */ + paiext_root.mapptr = alloc_percpu(struct paiext_mapptr); + if (!paiext_root.mapptr) { + /* Returing without refcnt adjustment is ok. The + * error code is handled by paiext_alloc() which + * decrements refcnt when an event can not be + * created. + */ + return -ENOMEM; + } + } + return 0; +} + +/* Protects against concurrent increment of sampler and counter member + * increments at the same time and prohibits concurrent execution of + * counting and sampling events. + * Ensures that analytics counter block is deallocated only when the + * sampling and counting on that cpu is zero. + * For details see paiext_alloc(). + */ +static DEFINE_MUTEX(paiext_reserve_mutex); + +/* Free all memory allocated for event counting/sampling setup */ +static void paiext_free(struct paiext_mapptr *mp) +{ + kfree(mp->mapptr->area); + kfree(mp->mapptr->paiext_cb); + kvfree(mp->mapptr->save); + kfree(mp->mapptr); + mp->mapptr = NULL; +} + +/* Release the PMU if event is the last perf event */ +static void paiext_event_destroy(struct perf_event *event) +{ + struct paiext_mapptr *mp = per_cpu_ptr(paiext_root.mapptr, event->cpu); + struct paiext_map *cpump = mp->mapptr; + + mutex_lock(&paiext_reserve_mutex); + cpump->event = NULL; + if (!--cpump->refcnt) /* Last reference gone */ + paiext_free(mp); + paiext_root_free(); + mutex_unlock(&paiext_reserve_mutex); + debug_sprintf_event(paiext_dbg, 4, "%s cpu %d mapptr %p\n", __func__, + event->cpu, mp->mapptr); + +} + +/* Used to avoid races in checking concurrent access of counting and + * sampling for pai_extension events. + * + * Only one instance of event pai_ext/NNPA_ALL/ for sampling is + * allowed and when this event is running, no counting event is allowed. + * Several counting events are allowed in parallel, but no sampling event + * is allowed while one (or more) counting events are running. + * + * This function is called in process context and it is safe to block. + * When the event initialization functions fails, no other call back will + * be invoked. + * + * Allocate the memory for the event. + */ +static int paiext_alloc(struct perf_event_attr *a, struct perf_event *event) +{ + struct paiext_mapptr *mp; + struct paiext_map *cpump; + int rc; + + mutex_lock(&paiext_reserve_mutex); + + rc = paiext_root_alloc(); + if (rc) + goto unlock; + + mp = per_cpu_ptr(paiext_root.mapptr, event->cpu); + cpump = mp->mapptr; + if (!cpump) { /* Paiext_map allocated? */ + rc = -ENOMEM; + cpump = kzalloc(sizeof(*cpump), GFP_KERNEL); + if (!cpump) + goto unlock; + + /* Allocate memory for counter area and counter extraction. + * These are + * - a 512 byte block and requires 512 byte boundary alignment. + * - a 1KB byte block and requires 1KB boundary alignment. + * Only the first counting event has to allocate the area. + * + * Note: This works with commit 59bb47985c1d by default. + * Backporting this to kernels without this commit might + * need adjustment. + */ + mp->mapptr = cpump; + cpump->area = kzalloc(PAIE1_CTRBLOCK_SZ, GFP_KERNEL); + cpump->paiext_cb = kzalloc(PAIE1_CB_SZ, GFP_KERNEL); + cpump->save = kvmalloc_array(paiext_cnt + 1, + sizeof(struct pai_userdata), + GFP_KERNEL); + if (!cpump->save || !cpump->area || !cpump->paiext_cb) { + paiext_free(mp); + goto unlock; + } + cpump->mode = a->sample_period ? PAI_MODE_SAMPLING + : PAI_MODE_COUNTER; + } else { + /* Multiple invocation, check whats active. + * Supported are multiple counter events or only one sampling + * event concurrently at any one time. + */ + if (cpump->mode == PAI_MODE_SAMPLING || + (cpump->mode == PAI_MODE_COUNTER && a->sample_period)) { + rc = -EBUSY; + goto unlock; + } + } + + rc = 0; + cpump->event = event; + ++cpump->refcnt; + +unlock: + if (rc) { + /* Error in allocation of event, decrement anchor. Since + * the event in not created, its destroy() function is never + * invoked. Adjust the reference counter for the anchor. + */ + paiext_root_free(); + } + mutex_unlock(&paiext_reserve_mutex); + /* If rc is non-zero, no increment of counter/sampler was done. */ + return rc; +} + +/* The PAI extension 1 control block supports up to 128 entries. Return + * the index within PAIE1_CB given the event number. Also validate event + * number. + */ +static int paiext_event_valid(struct perf_event *event) +{ + u64 cfg = event->attr.config; + + if (cfg >= PAI_NNPA_BASE && cfg <= PAI_NNPA_BASE + paiext_cnt) { + /* Offset NNPA in paiext_cb */ + event->hw.config_base = offsetof(struct paiext_cb, acc); + return 0; + } + return -EINVAL; +} + +/* Might be called on different CPU than the one the event is intended for. */ +static int paiext_event_init(struct perf_event *event) +{ + struct perf_event_attr *a = &event->attr; + int rc; + + /* PMU pai_ext registered as PERF_TYPE_RAW, check event type */ + if (a->type != PERF_TYPE_RAW && event->pmu->type != a->type) + return -ENOENT; + /* PAI extension event must be valid and in supported range */ + rc = paiext_event_valid(event); + if (rc) + return rc; + /* Allow only CPU wide operation, no process context for now. */ + if (event->hw.target || event->cpu == -1) + return -ENOENT; + /* Allow only event NNPA_ALL for sampling. */ + if (a->sample_period && a->config != PAI_NNPA_BASE) + return -EINVAL; + /* Prohibit exclude_user event selection */ + if (a->exclude_user) + return -EINVAL; + + rc = paiext_alloc(a, event); + if (rc) + return rc; + event->hw.last_tag = 0; + event->destroy = paiext_event_destroy; + + if (a->sample_period) { + a->sample_period = 1; + a->freq = 0; + /* Register for paicrypt_sched_task() to be called */ + event->attach_state |= PERF_ATTACH_SCHED_CB; + /* Add raw data which are the memory mapped counters */ + a->sample_type |= PERF_SAMPLE_RAW; + /* Turn off inheritance */ + a->inherit = 0; + } + + return 0; +} + +static u64 paiext_getctr(struct paiext_map *cpump, int nr) +{ + return cpump->area[nr]; +} + +/* Read the counter values. Return value from location in buffer. For event + * NNPA_ALL sum up all events. + */ +static u64 paiext_getdata(struct perf_event *event) +{ + struct paiext_mapptr *mp = this_cpu_ptr(paiext_root.mapptr); + struct paiext_map *cpump = mp->mapptr; + u64 sum = 0; + int i; + + if (event->attr.config != PAI_NNPA_BASE) + return paiext_getctr(cpump, event->attr.config - PAI_NNPA_BASE); + + for (i = 1; i <= paiext_cnt; i++) + sum += paiext_getctr(cpump, i); + + return sum; +} + +static u64 paiext_getall(struct perf_event *event) +{ + return paiext_getdata(event); +} + +static void paiext_read(struct perf_event *event) +{ + u64 prev, new, delta; + + prev = local64_read(&event->hw.prev_count); + new = paiext_getall(event); + local64_set(&event->hw.prev_count, new); + delta = new - prev; + local64_add(delta, &event->count); +} + +static void paiext_start(struct perf_event *event, int flags) +{ + u64 sum; + + if (event->hw.last_tag) + return; + event->hw.last_tag = 1; + sum = paiext_getall(event); /* Get current value */ + local64_set(&event->hw.prev_count, sum); + local64_set(&event->count, 0); +} + +static int paiext_add(struct perf_event *event, int flags) +{ + struct paiext_mapptr *mp = this_cpu_ptr(paiext_root.mapptr); + struct paiext_map *cpump = mp->mapptr; + struct paiext_cb *pcb = cpump->paiext_cb; + + if (++cpump->active_events == 1) { + S390_lowcore.aicd = virt_to_phys(cpump->paiext_cb); + pcb->acc = virt_to_phys(cpump->area) | 0x1; + /* Enable CPU instruction lookup for PAIE1 control block */ + __ctl_set_bit(0, 49); + debug_sprintf_event(paiext_dbg, 4, "%s 1508 %llx acc %llx\n", + __func__, S390_lowcore.aicd, pcb->acc); + } + if (flags & PERF_EF_START && !event->attr.sample_period) { + /* Only counting needs initial counter value */ + paiext_start(event, PERF_EF_RELOAD); + } + event->hw.state = 0; + if (event->attr.sample_period) { + cpump->event = event; + perf_sched_cb_inc(event->pmu); + } + return 0; +} + +static void paiext_stop(struct perf_event *event, int flags) +{ + paiext_read(event); + event->hw.state = PERF_HES_STOPPED; +} + +static void paiext_del(struct perf_event *event, int flags) +{ + struct paiext_mapptr *mp = this_cpu_ptr(paiext_root.mapptr); + struct paiext_map *cpump = mp->mapptr; + struct paiext_cb *pcb = cpump->paiext_cb; + + if (event->attr.sample_period) + perf_sched_cb_dec(event->pmu); + if (!event->attr.sample_period) { + /* Only counting needs to read counter */ + paiext_stop(event, PERF_EF_UPDATE); + } + if (--cpump->active_events == 0) { + /* Disable CPU instruction lookup for PAIE1 control block */ + __ctl_clear_bit(0, 49); + pcb->acc = 0; + S390_lowcore.aicd = 0; + debug_sprintf_event(paiext_dbg, 4, "%s 1508 %llx acc %llx\n", + __func__, S390_lowcore.aicd, pcb->acc); + } +} + +/* Create raw data and save it in buffer. Returns number of bytes copied. + * Saves only positive counter entries of the form + * 2 bytes: Number of counter + * 8 bytes: Value of counter + */ +static size_t paiext_copy(struct paiext_map *cpump) +{ + struct pai_userdata *userdata = cpump->save; + int i, outidx = 0; + + for (i = 1; i <= paiext_cnt; i++) { + u64 val = paiext_getctr(cpump, i); + + if (val) { + userdata[outidx].num = i; + userdata[outidx].value = val; + outidx++; + } + } + return outidx * sizeof(*userdata); +} + +/* Write sample when one or more counters values are nonzero. + * + * Note: The function paiext_sched_task() and paiext_push_sample() are not + * invoked after function paiext_del() has been called because of function + * perf_sched_cb_dec(). + * The function paiext_sched_task() and paiext_push_sample() are only + * called when sampling is active. Function perf_sched_cb_inc() + * has been invoked to install function paiext_sched_task() as call back + * to run at context switch time (see paiext_add()). + * + * This causes function perf_event_context_sched_out() and + * perf_event_context_sched_in() to check whether the PMU has installed an + * sched_task() callback. That callback is not active after paiext_del() + * returns and has deleted the event on that CPU. + */ +static int paiext_push_sample(void) +{ + struct paiext_mapptr *mp = this_cpu_ptr(paiext_root.mapptr); + struct paiext_map *cpump = mp->mapptr; + struct perf_event *event = cpump->event; + struct perf_sample_data data; + struct perf_raw_record raw; + struct pt_regs regs; + size_t rawsize; + int overflow; + + rawsize = paiext_copy(cpump); + if (!rawsize) /* No incremented counters */ + return 0; + + /* Setup perf sample */ + memset(®s, 0, sizeof(regs)); + memset(&raw, 0, sizeof(raw)); + memset(&data, 0, sizeof(data)); + perf_sample_data_init(&data, 0, event->hw.last_period); + if (event->attr.sample_type & PERF_SAMPLE_TID) { + data.tid_entry.pid = task_tgid_nr(current); + data.tid_entry.tid = task_pid_nr(current); + } + if (event->attr.sample_type & PERF_SAMPLE_TIME) + data.time = event->clock(); + if (event->attr.sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) + data.id = event->id; + if (event->attr.sample_type & PERF_SAMPLE_CPU) + data.cpu_entry.cpu = smp_processor_id(); + if (event->attr.sample_type & PERF_SAMPLE_RAW) { + raw.frag.size = rawsize; + raw.frag.data = cpump->save; + raw.size = raw.frag.size; + data.raw = &raw; + data.sample_flags |= PERF_SAMPLE_RAW; + } + + overflow = perf_event_overflow(event, &data, ®s); + perf_event_update_userpage(event); + /* Clear lowcore area after read */ + memset(cpump->area, 0, PAIE1_CTRBLOCK_SZ); + return overflow; +} + +/* Called on schedule-in and schedule-out. No access to event structure, + * but for sampling only event NNPA_ALL is allowed. + */ +static void paiext_sched_task(struct perf_event_context *ctx, bool sched_in) +{ + /* We started with a clean page on event installation. So read out + * results on schedule_out and if page was dirty, clear values. + */ + if (!sched_in) + paiext_push_sample(); +} + +/* Attribute definitions for pai extension1 interface. As with other CPU + * Measurement Facilities, there is one attribute per mapped counter. + * The number of mapped counters may vary per machine generation. Use + * the QUERY PROCESSOR ACTIVITY COUNTER INFORMATION (QPACI) instruction + * to determine the number of mapped counters. The instructions returns + * a positive number, which is the highest number of supported counters. + * All counters less than this number are also supported, there are no + * holes. A returned number of zero means no support for mapped counters. + * + * The identification of the counter is a unique number. The chosen range + * is 0x1800 + offset in mapped kernel page. + * All CPU Measurement Facility counters identifiers must be unique and + * the numbers from 0 to 496 are already used for the CPU Measurement + * Counter facility. Number 0x1000 to 0x103e are used for PAI cryptography + * counters. + * Numbers 0xb0000, 0xbc000 and 0xbd000 are already + * used for the CPU Measurement Sampling facility. + */ +PMU_FORMAT_ATTR(event, "config:0-63"); + +static struct attribute *paiext_format_attr[] = { + &format_attr_event.attr, + NULL, +}; + +static struct attribute_group paiext_events_group = { + .name = "events", + .attrs = NULL, /* Filled in attr_event_init() */ +}; + +static struct attribute_group paiext_format_group = { + .name = "format", + .attrs = paiext_format_attr, +}; + +static const struct attribute_group *paiext_attr_groups[] = { + &paiext_events_group, + &paiext_format_group, + NULL, +}; + +/* Performance monitoring unit for mapped counters */ +static struct pmu paiext = { + .task_ctx_nr = perf_invalid_context, + .event_init = paiext_event_init, + .add = paiext_add, + .del = paiext_del, + .start = paiext_start, + .stop = paiext_stop, + .read = paiext_read, + .sched_task = paiext_sched_task, + .attr_groups = paiext_attr_groups, +}; + +/* List of symbolic PAI extension 1 NNPA counter names. */ +static const char * const paiext_ctrnames[] = { + [0] = "NNPA_ALL", + [1] = "NNPA_ADD", + [2] = "NNPA_SUB", + [3] = "NNPA_MUL", + [4] = "NNPA_DIV", + [5] = "NNPA_MIN", + [6] = "NNPA_MAX", + [7] = "NNPA_LOG", + [8] = "NNPA_EXP", + [9] = "NNPA_IBM_RESERVED_9", + [10] = "NNPA_RELU", + [11] = "NNPA_TANH", + [12] = "NNPA_SIGMOID", + [13] = "NNPA_SOFTMAX", + [14] = "NNPA_BATCHNORM", + [15] = "NNPA_MAXPOOL2D", + [16] = "NNPA_AVGPOOL2D", + [17] = "NNPA_LSTMACT", + [18] = "NNPA_GRUACT", + [19] = "NNPA_CONVOLUTION", + [20] = "NNPA_MATMUL_OP", + [21] = "NNPA_MATMUL_OP_BCAST23", + [22] = "NNPA_SMALLBATCH", + [23] = "NNPA_LARGEDIM", + [24] = "NNPA_SMALLTENSOR", + [25] = "NNPA_1MFRAME", + [26] = "NNPA_2GFRAME", + [27] = "NNPA_ACCESSEXCEPT", +}; + +static void __init attr_event_free(struct attribute **attrs, int num) +{ + struct perf_pmu_events_attr *pa; + struct device_attribute *dap; + int i; + + for (i = 0; i < num; i++) { + dap = container_of(attrs[i], struct device_attribute, attr); + pa = container_of(dap, struct perf_pmu_events_attr, attr); + kfree(pa); + } + kfree(attrs); +} + +static int __init attr_event_init_one(struct attribute **attrs, int num) +{ + struct perf_pmu_events_attr *pa; + + pa = kzalloc(sizeof(*pa), GFP_KERNEL); + if (!pa) + return -ENOMEM; + + sysfs_attr_init(&pa->attr.attr); + pa->id = PAI_NNPA_BASE + num; + pa->attr.attr.name = paiext_ctrnames[num]; + pa->attr.attr.mode = 0444; + pa->attr.show = cpumf_events_sysfs_show; + pa->attr.store = NULL; + attrs[num] = &pa->attr.attr; + return 0; +} + +/* Create PMU sysfs event attributes on the fly. */ +static int __init attr_event_init(void) +{ + struct attribute **attrs; + int ret, i; + + attrs = kmalloc_array(ARRAY_SIZE(paiext_ctrnames) + 1, sizeof(*attrs), + GFP_KERNEL); + if (!attrs) + return -ENOMEM; + for (i = 0; i < ARRAY_SIZE(paiext_ctrnames); i++) { + ret = attr_event_init_one(attrs, i); + if (ret) { + attr_event_free(attrs, i - 1); + return ret; + } + } + attrs[i] = NULL; + paiext_events_group.attrs = attrs; + return 0; +} + +static int __init paiext_init(void) +{ + struct qpaci_info_block ib; + int rc = -ENOMEM; + + if (!test_facility(197)) + return 0; + + qpaci(&ib); + paiext_cnt = ib.num_nnpa; + if (paiext_cnt >= PAI_NNPA_MAXCTR) + paiext_cnt = PAI_NNPA_MAXCTR; + if (!paiext_cnt) + return 0; + + rc = attr_event_init(); + if (rc) { + pr_err("Creation of PMU " KMSG_COMPONENT " /sysfs failed\n"); + return rc; + } + + /* Setup s390dbf facility */ + paiext_dbg = debug_register(KMSG_COMPONENT, 2, 256, 128); + if (!paiext_dbg) { + pr_err("Registration of s390dbf " KMSG_COMPONENT " failed\n"); + rc = -ENOMEM; + goto out_init; + } + debug_register_view(paiext_dbg, &debug_sprintf_view); + + rc = perf_pmu_register(&paiext, KMSG_COMPONENT, -1); + if (rc) { + pr_err("Registration of " KMSG_COMPONENT " PMU failed with " + "rc=%i\n", rc); + goto out_pmu; + } + + return 0; + +out_pmu: + debug_unregister_view(paiext_dbg, &debug_sprintf_view); + debug_unregister(paiext_dbg); +out_init: + attr_event_free(paiext_events_group.attrs, + ARRAY_SIZE(paiext_ctrnames) + 1); + return rc; +} + +device_initcall(paiext_init); |