diff options
Diffstat (limited to 'arch/s390/kernel/perf_cpum_sf.c')
| -rw-r--r-- | arch/s390/kernel/perf_cpum_sf.c | 911 |
1 files changed, 457 insertions, 454 deletions
diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index bfabeb1889cc..459af23a47a5 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -5,8 +5,7 @@ * Copyright IBM Corp. 2013, 2018 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> */ -#define KMSG_COMPONENT "cpum_sf" -#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt +#define pr_fmt(fmt) "cpum_sf: " fmt #include <linux/kernel.h> #include <linux/kernel_stat.h> @@ -14,7 +13,6 @@ #include <linux/percpu.h> #include <linux/pid.h> #include <linux/notifier.h> -#include <linux/export.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/moduleparam.h> @@ -22,6 +20,23 @@ #include <asm/irq.h> #include <asm/debug.h> #include <asm/timex.h> +#include <linux/io.h> + +/* Perf PMU definitions for the sampling facility */ +#define PERF_CPUM_SF_MAX_CTR 2 +#define PERF_EVENT_CPUM_SF 0xB0000UL /* Event: Basic-sampling */ +#define PERF_EVENT_CPUM_SF_DIAG 0xBD000UL /* Event: Combined-sampling */ +#define PERF_CPUM_SF_BASIC_MODE 0x0001 /* Basic-sampling flag */ +#define PERF_CPUM_SF_DIAG_MODE 0x0002 /* Diagnostic-sampling flag */ +#define PERF_CPUM_SF_FREQ_MODE 0x0008 /* Sampling with frequency */ + +#define OVERFLOW_REG(hwc) ((hwc)->extra_reg.config) +#define SFB_ALLOC_REG(hwc) ((hwc)->extra_reg.alloc) +#define TEAR_REG(hwc) ((hwc)->last_tag) +#define SAMPL_RATE(hwc) ((hwc)->event_base) +#define SAMPL_FLAGS(hwc) ((hwc)->config_base) +#define SAMPL_DIAG_MODE(hwc) (SAMPL_FLAGS(hwc) & PERF_CPUM_SF_DIAG_MODE) +#define SAMPL_FREQ_MODE(hwc) (SAMPL_FLAGS(hwc) & PERF_CPUM_SF_FREQ_MODE) /* Minimum number of sample-data-block-tables: * At least one table is required for the sampling buffer structure. @@ -42,7 +57,7 @@ #define CPUM_SF_SDBT_TL_OFFSET (CPUM_SF_SDB_PER_TABLE * 8) static inline int require_table_link(const void *sdbt) { - return ((unsigned long) sdbt & ~PAGE_MASK) == CPUM_SF_SDBT_TL_OFFSET; + return ((unsigned long)sdbt & ~PAGE_MASK) == CPUM_SF_SDBT_TL_OFFSET; } /* Minimum and maximum sampling buffer sizes: @@ -99,15 +114,55 @@ static DEFINE_PER_CPU(struct cpu_hw_sf, cpu_hw_sf); /* Debug feature */ static debug_info_t *sfdbg; +/* Sampling control helper functions */ +static inline unsigned long freq_to_sample_rate(struct hws_qsi_info_block *qsi, + unsigned long freq) +{ + return (USEC_PER_SEC / freq) * qsi->cpu_speed; +} + +static inline unsigned long sample_rate_to_freq(struct hws_qsi_info_block *qsi, + unsigned long rate) +{ + return USEC_PER_SEC * qsi->cpu_speed / rate; +} + +/* Return pointer to trailer entry of an sample data block */ +static inline struct hws_trailer_entry *trailer_entry_ptr(unsigned long v) +{ + void *ret; + + ret = (void *)v; + ret += PAGE_SIZE; + ret -= sizeof(struct hws_trailer_entry); + + return ret; +} + +/* + * Return true if the entry in the sample data block table (sdbt) + * is a link to the next sdbt + */ +static inline int is_link_entry(unsigned long *s) +{ + return *s & 0x1UL ? 1 : 0; +} + +/* Return pointer to the linked sdbt */ +static inline unsigned long *get_next_sdbt(unsigned long *s) +{ + return phys_to_virt(*s & ~0x1UL); +} + /* * sf_disable() - Switch off sampling facility */ -static int sf_disable(void) +static void sf_disable(void) { struct hws_lsctl_request_block sreq; memset(&sreq, 0, sizeof(sreq)); - return lsctl(&sreq); + lsctl(&sreq); } /* @@ -123,57 +178,44 @@ static int sf_buffer_available(struct cpu_hw_sf *cpuhw) */ static void free_sampling_buffer(struct sf_buffer *sfb) { - unsigned long *sdbt, *curr; - - if (!sfb->sdbt) - return; + unsigned long *sdbt, *curr, *head; sdbt = sfb->sdbt; - curr = sdbt; - + if (!sdbt) + return; + sfb->sdbt = NULL; /* Free the SDBT after all SDBs are processed... */ - while (1) { - if (!*curr || !sdbt) - break; - - /* Process table-link entries */ + head = sdbt; + curr = sdbt; + do { if (is_link_entry(curr)) { + /* Process table-link entries */ curr = get_next_sdbt(curr); - if (sdbt) - free_page((unsigned long) sdbt); - - /* If the origin is reached, sampling buffer is freed */ - if (curr == sfb->sdbt) - break; - else - sdbt = curr; + free_page((unsigned long)sdbt); + sdbt = curr; } else { /* Process SDB pointer */ - if (*curr) { - free_page(*curr); - curr++; - } + free_page((unsigned long)phys_to_virt(*curr)); + curr++; } - } - - debug_sprintf_event(sfdbg, 5, - "free_sampling_buffer: freed sdbt=%p\n", sfb->sdbt); + } while (curr != head); memset(sfb, 0, sizeof(*sfb)); } static int alloc_sample_data_block(unsigned long *sdbt, gfp_t gfp_flags) { - unsigned long sdb, *trailer; + struct hws_trailer_entry *te; + unsigned long sdb; /* Allocate and initialize sample-data-block */ sdb = get_zeroed_page(gfp_flags); if (!sdb) return -ENOMEM; - trailer = trailer_entry_ptr(sdb); - *trailer = SDB_TE_ALERT_REQ_MASK; + te = trailer_entry_ptr(sdb); + te->header.a = 1; /* Link SDB into the sample-data-block-table */ - *sdbt = sdb; + *sdbt = virt_to_phys((void *)sdb); return 0; } @@ -193,7 +235,7 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb, unsigned long num_sdb, gfp_t gfp_flags) { int i, rc; - unsigned long *new, *tail; + unsigned long *new, *tail, *tail_prev = NULL; if (!sfb->sdbt || !sfb->tail) return -EINVAL; @@ -212,10 +254,9 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb, * the sampling buffer origin. */ if (sfb->sdbt != get_next_sdbt(tail)) { - debug_sprintf_event(sfdbg, 3, "realloc_sampling_buffer: " - "sampling buffer is not linked: origin=%p" - "tail=%p\n", - (void *) sfb->sdbt, (void *) tail); + debug_sprintf_event(sfdbg, 3, "%s buffer not linked origin %#lx tail %#lx\n", + __func__, (unsigned long)sfb->sdbt, + (unsigned long)tail); return -EINVAL; } @@ -224,14 +265,15 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb, for (i = 0; i < num_sdb; i++) { /* Allocate a new SDB-table if it is full. */ if (require_table_link(tail)) { - new = (unsigned long *) get_zeroed_page(gfp_flags); + new = (unsigned long *)get_zeroed_page(gfp_flags); if (!new) { rc = -ENOMEM; break; } sfb->num_sdbt++; /* Link current page to tail of chain */ - *tail = (unsigned long)(void *) new + 1; + *tail = virt_to_phys((void *)new) + 1; + tail_prev = tail; tail = new; } @@ -241,19 +283,28 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb, * issue, a new realloc call (if required) might succeed. */ rc = alloc_sample_data_block(tail, gfp_flags); - if (rc) + if (rc) { + /* Undo last SDBT. An SDBT with no SDB at its first + * entry but with an SDBT entry instead can not be + * handled by the interrupt handler code. + * Avoid this situation. + */ + if (tail_prev) { + sfb->num_sdbt--; + free_page((unsigned long)new); + tail = tail_prev; + } break; + } sfb->num_sdb++; tail++; + tail_prev = new = NULL; /* Allocated at least one SBD */ } /* Link sampling buffer to its origin */ - *tail = (unsigned long) sfb->sdbt + 1; + *tail = virt_to_phys(sfb->sdbt) + 1; sfb->tail = tail; - debug_sprintf_event(sfdbg, 4, "realloc_sampling_buffer: new buffer" - " settings: sdbt=%lu sdb=%lu\n", - sfb->num_sdbt, sfb->num_sdb); return rc; } @@ -276,7 +327,7 @@ static int alloc_sampling_buffer(struct sf_buffer *sfb, unsigned long num_sdb) return -EINVAL; /* Allocate the sample-data-block-table origin */ - sfb->sdbt = (unsigned long *) get_zeroed_page(GFP_KERNEL); + sfb->sdbt = (unsigned long *)get_zeroed_page(GFP_KERNEL); if (!sfb->sdbt) return -ENOMEM; sfb->num_sdb = 0; @@ -286,18 +337,12 @@ static int alloc_sampling_buffer(struct sf_buffer *sfb, unsigned long num_sdb) * realloc_sampling_buffer() invocation. */ sfb->tail = sfb->sdbt; - *sfb->tail = (unsigned long)(void *) sfb->sdbt + 1; + *sfb->tail = virt_to_phys((void *)sfb->sdbt) + 1; /* Allocate requested number of sample-data-blocks */ rc = realloc_sampling_buffer(sfb, num_sdb, GFP_KERNEL); - if (rc) { + if (rc) free_sampling_buffer(sfb); - debug_sprintf_event(sfdbg, 4, "alloc_sampling_buffer: " - "realloc_sampling_buffer failed with rc=%i\n", rc); - } else - debug_sprintf_event(sfdbg, 4, - "alloc_sampling_buffer: tear=%p dear=%p\n", - sfb->sdbt, (void *) *sfb->sdbt); return rc; } @@ -309,8 +354,8 @@ static void sfb_set_limits(unsigned long min, unsigned long max) CPUM_SF_MAX_SDB = max; memset(&si, 0, sizeof(si)); - if (!qsi(&si)) - CPUM_SF_SDB_DIAG_FACTOR = DIV_ROUND_UP(si.dsdes, si.bsdes); + qsi(&si); + CPUM_SF_SDB_DIAG_FACTOR = DIV_ROUND_UP(si.dsdes, si.bsdes); } static unsigned long sfb_max_limit(struct hw_perf_event *hwc) @@ -329,12 +374,6 @@ static unsigned long sfb_pending_allocs(struct sf_buffer *sfb, return 0; } -static int sfb_has_pending_allocs(struct sf_buffer *sfb, - struct hw_perf_event *hwc) -{ - return sfb_pending_allocs(sfb, hwc) > 0; -} - static void sfb_account_allocs(unsigned long num, struct hw_perf_event *hwc) { /* Limit the number of SDBs to not exceed the maximum */ @@ -351,45 +390,45 @@ static void sfb_init_allocs(unsigned long num, struct hw_perf_event *hwc) static void deallocate_buffers(struct cpu_hw_sf *cpuhw) { - if (cpuhw->sfb.sdbt) + if (sf_buffer_available(cpuhw)) free_sampling_buffer(&cpuhw->sfb); } static int allocate_buffers(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc) { - unsigned long n_sdb, freq, factor; - size_t sample_size; + unsigned long n_sdb, freq; /* Calculate sampling buffers using 4K pages * - * 1. Determine the sample data size which depends on the used - * sampling functions, for example, basic-sampling or - * basic-sampling with diagnostic-sampling. + * 1. The sampling size is 32 bytes for basic sampling. This size + * is the same for all machine types. Diagnostic + * sampling uses auxlilary data buffer setup which provides the + * memory for SDBs using linux common code auxiliary trace + * setup. * - * 2. Use the sampling frequency as input. The sampling buffer is - * designed for almost one second. This can be adjusted through - * the "factor" variable. - * In any case, alloc_sampling_buffer() sets the Alert Request + * 2. Function alloc_sampling_buffer() sets the Alert Request * Control indicator to trigger a measurement-alert to harvest - * sample-data-blocks (sdb). + * sample-data-blocks (SDB). This is done per SDB. This + * measurement alert interrupt fires quick enough to handle + * one SDB, on very high frequency and work loads there might + * be 2 to 3 SBDs available for sample processing. + * Currently there is no need for setup alert request on every + * n-th page. This is counterproductive as one IRQ triggers + * a very high number of samples to be processed at one IRQ. * - * 3. Compute the number of sample-data-blocks and ensure a minimum - * of CPUM_SF_MIN_SDB. Also ensure the upper limit does not - * exceed a "calculated" maximum. The symbolic maximum is - * designed for basic-sampling only and needs to be increased if - * diagnostic-sampling is active. - * See also the remarks for these symbolic constants. + * 3. Use the sampling frequency as input. + * Compute the number of SDBs and ensure a minimum + * of CPUM_SF_MIN_SDB. Depending on frequency add some more + * SDBs to handle a higher sampling rate. + * Use a minimum of CPUM_SF_MIN_SDB and allow for 100 samples + * (one SDB) for every 10000 HZ frequency increment. * * 4. Compute the number of sample-data-block-tables (SDBT) and * ensure a minimum of CPUM_SF_MIN_SDBT (one table can manage up * to 511 SDBs). */ - sample_size = sizeof(struct hws_basic_entry); freq = sample_rate_to_freq(&cpuhw->qsi, SAMPL_RATE(hwc)); - factor = 1; - n_sdb = DIV_ROUND_UP(freq, factor * ((PAGE_SIZE-64) / sample_size)); - if (n_sdb < CPUM_SF_MIN_SDB) - n_sdb = CPUM_SF_MIN_SDB; + n_sdb = CPUM_SF_MIN_SDB + DIV_ROUND_UP(freq, 10000); /* If there is already a sampling buffer allocated, it is very likely * that the sampling facility is enabled too. If the event to be @@ -403,12 +442,6 @@ static int allocate_buffers(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc) if (sf_buffer_available(cpuhw)) return 0; - debug_sprintf_event(sfdbg, 3, - "allocate_buffers: rate=%lu f=%lu sdb=%lu/%lu" - " sample_size=%lu cpuhw=%p\n", - SAMPL_RATE(hwc), freq, n_sdb, sfb_max_limit(hwc), - sample_size, cpuhw); - return alloc_sampling_buffer(&cpuhw->sfb, sfb_pending_allocs(&cpuhw->sfb, hwc)); } @@ -465,8 +498,6 @@ static void sfb_account_overflows(struct cpu_hw_sf *cpuhw, if (num) sfb_account_allocs(num, hwc); - debug_sprintf_event(sfdbg, 5, "sfb: overflow: overflow=%llu ratio=%lu" - " num=%lu\n", OVERFLOW_REG(hwc), ratio, num); OVERFLOW_REG(hwc) = 0; } @@ -484,13 +515,11 @@ static void sfb_account_overflows(struct cpu_hw_sf *cpuhw, static void extend_sampling_buffer(struct sf_buffer *sfb, struct hw_perf_event *hwc) { - unsigned long num, num_old; - int rc; + unsigned long num; num = sfb_pending_allocs(sfb, hwc); if (!num) return; - num_old = sfb->num_sdb; /* Disable the sampling facility to reset any states and also * clear pending measurement alerts. @@ -502,61 +531,32 @@ static void extend_sampling_buffer(struct sf_buffer *sfb, * called by perf. Because this is a reallocation, it is fine if the * new SDB-request cannot be satisfied immediately. */ - rc = realloc_sampling_buffer(sfb, num, GFP_ATOMIC); - if (rc) - debug_sprintf_event(sfdbg, 5, "sfb: extend: realloc " - "failed with rc=%i\n", rc); - - if (sfb_has_pending_allocs(sfb, hwc)) - debug_sprintf_event(sfdbg, 5, "sfb: extend: " - "req=%lu alloc=%lu remaining=%lu\n", - num, sfb->num_sdb - num_old, - sfb_pending_allocs(sfb, hwc)); + realloc_sampling_buffer(sfb, num, GFP_ATOMIC); } - /* Number of perf events counting hardware events */ -static atomic_t num_events; +static refcount_t num_events; /* Used to avoid races in calling reserve/release_cpumf_hardware */ static DEFINE_MUTEX(pmc_reserve_mutex); #define PMC_INIT 0 #define PMC_RELEASE 1 -#define PMC_FAILURE 2 static void setup_pmc_cpu(void *flags) { - int err; - struct cpu_hw_sf *cpusf = this_cpu_ptr(&cpu_hw_sf); + struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf); - err = 0; - switch (*((int *) flags)) { + sf_disable(); + switch (*((int *)flags)) { case PMC_INIT: - memset(cpusf, 0, sizeof(*cpusf)); - err = qsi(&cpusf->qsi); - if (err) - break; - cpusf->flags |= PMU_F_RESERVED; - err = sf_disable(); - if (err) - pr_err("Switching off the sampling facility failed " - "with rc=%i\n", err); - debug_sprintf_event(sfdbg, 5, - "setup_pmc_cpu: initialized: cpuhw=%p\n", cpusf); + memset(cpuhw, 0, sizeof(*cpuhw)); + qsi(&cpuhw->qsi); + cpuhw->flags |= PMU_F_RESERVED; break; case PMC_RELEASE: - cpusf->flags &= ~PMU_F_RESERVED; - err = sf_disable(); - if (err) { - pr_err("Switching off the sampling facility failed " - "with rc=%i\n", err); - } else - deallocate_buffers(cpusf); - debug_sprintf_event(sfdbg, 5, - "setup_pmc_cpu: released: cpuhw=%p\n", cpusf); + cpuhw->flags &= ~PMU_F_RESERVED; + deallocate_buffers(cpuhw); break; } - if (err) - *((int *) flags) |= PMC_FAILURE; } static void release_pmc_hardware(void) @@ -567,27 +567,19 @@ static void release_pmc_hardware(void) on_each_cpu(setup_pmc_cpu, &flags, 1); } -static int reserve_pmc_hardware(void) +static void reserve_pmc_hardware(void) { int flags = PMC_INIT; on_each_cpu(setup_pmc_cpu, &flags, 1); - if (flags & PMC_FAILURE) { - release_pmc_hardware(); - return -ENODEV; - } irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT); - - return 0; } static void hw_perf_event_destroy(struct perf_event *event) { /* Release PMC if this is the last perf event */ - if (!atomic_add_unless(&num_events, -1, 1)) { - mutex_lock(&pmc_reserve_mutex); - if (atomic_dec_return(&num_events) == 0) - release_pmc_hardware(); + if (refcount_dec_and_mutex_lock(&num_events, &pmc_reserve_mutex)) { + release_pmc_hardware(); mutex_unlock(&pmc_reserve_mutex); } } @@ -599,13 +591,6 @@ static void hw_init_period(struct hw_perf_event *hwc, u64 period) local64_set(&hwc->period_left, hwc->sample_period); } -static void hw_reset_registers(struct hw_perf_event *hwc, - unsigned long *sdbt_origin) -{ - /* (Re)set to first sample-data-block-table */ - TEAR_REG(hwc) = (unsigned long) sdbt_origin; -} - static unsigned long hw_limit_rate(const struct hws_qsi_info_block *si, unsigned long rate) { @@ -660,8 +645,9 @@ static void cpumsf_output_event_pid(struct perf_event *event, /* Protect callchain buffers, tasks */ rcu_read_lock(); - perf_prepare_sample(&header, data, event, regs); - if (perf_output_begin(&handle, event, header.size)) + perf_prepare_sample(data, event, regs); + perf_prepare_header(&header, data, event, regs); + if (perf_output_begin(&handle, data, event, header.size)) goto out; /* Update the process ID (see also kernel/events/core.c) */ @@ -674,30 +660,92 @@ out: rcu_read_unlock(); } +static unsigned long getrate(bool freq, unsigned long sample, + struct hws_qsi_info_block *si) +{ + unsigned long rate; + + if (freq) { + rate = freq_to_sample_rate(si, sample); + rate = hw_limit_rate(si, rate); + } else { + /* The min/max sampling rates specifies the valid range + * of sample periods. If the specified sample period is + * out of range, limit the period to the range boundary. + */ + rate = hw_limit_rate(si, sample); + + /* The perf core maintains a maximum sample rate that is + * configurable through the sysctl interface. Ensure the + * sampling rate does not exceed this value. This also helps + * to avoid throttling when pushing samples with + * perf_event_overflow(). + */ + if (sample_rate_to_freq(si, rate) > + sysctl_perf_event_sample_rate) { + rate = 0; + } + } + return rate; +} + +/* The sampling information (si) contains information about the + * min/max sampling intervals and the CPU speed. So calculate the + * correct sampling interval and avoid the whole period adjust + * feedback loop. + * + * Since the CPU Measurement sampling facility can not handle frequency + * calculate the sampling interval when frequency is specified using + * this formula: + * interval := cpu_speed * 1000000 / sample_freq + * + * Returns errno on bad input and zero on success with parameter interval + * set to the correct sampling rate. + * + * Note: This function turns off freq bit to avoid calling function + * perf_adjust_period(). This causes frequency adjustment in the common + * code part which causes tremendous variations in the counter values. + */ +static int __hw_perf_event_init_rate(struct perf_event *event, + struct hws_qsi_info_block *si) +{ + struct perf_event_attr *attr = &event->attr; + struct hw_perf_event *hwc = &event->hw; + unsigned long rate; + + if (attr->freq) { + if (!attr->sample_freq) + return -EINVAL; + rate = getrate(attr->freq, attr->sample_freq, si); + attr->freq = 0; /* Don't call perf_adjust_period() */ + SAMPL_FLAGS(hwc) |= PERF_CPUM_SF_FREQ_MODE; + } else { + rate = getrate(attr->freq, attr->sample_period, si); + if (!rate) + return -EINVAL; + } + attr->sample_period = rate; + SAMPL_RATE(hwc) = rate; + hw_init_period(hwc, SAMPL_RATE(hwc)); + return 0; +} + static int __hw_perf_event_init(struct perf_event *event) { struct cpu_hw_sf *cpuhw; struct hws_qsi_info_block si; struct perf_event_attr *attr = &event->attr; struct hw_perf_event *hwc = &event->hw; - unsigned long rate; - int cpu, err; + int cpu, err = 0; /* Reserve CPU-measurement sampling facility */ - err = 0; - if (!atomic_inc_not_zero(&num_events)) { - mutex_lock(&pmc_reserve_mutex); - if (atomic_read(&num_events) == 0 && reserve_pmc_hardware()) - err = -EBUSY; - else - atomic_inc(&num_events); - mutex_unlock(&pmc_reserve_mutex); + mutex_lock(&pmc_reserve_mutex); + if (!refcount_inc_not_zero(&num_events)) { + reserve_pmc_hardware(); + refcount_set(&num_events, 1); } event->destroy = hw_perf_event_destroy; - if (err) - goto out; - /* Access per-CPU sampling information (query sampling info) */ /* * The event->cpu value can be -1 to count on every CPU, for example, @@ -709,9 +757,9 @@ static int __hw_perf_event_init(struct perf_event *event) */ memset(&si, 0, sizeof(si)); cpuhw = NULL; - if (event->cpu == -1) + if (event->cpu == -1) { qsi(&si); - else { + } else { /* Event is pinned to a particular CPU, retrieve the per-CPU * sampling structure for accessing the CPU-specific QSI. */ @@ -728,6 +776,12 @@ static int __hw_perf_event_init(struct perf_event *event) goto out; } + if (si.ribm & CPU_MF_SF_RIBM_NOTAV) { + pr_warn("CPU Measurement Facility sampling is temporarily not available\n"); + err = -EBUSY; + goto out; + } + /* Always enable basic sampling */ SAMPL_FLAGS(hwc) = PERF_CPUM_SF_BASIC_MODE; @@ -742,55 +796,13 @@ static int __hw_perf_event_init(struct perf_event *event) SAMPL_FLAGS(hwc) |= PERF_CPUM_SF_DIAG_MODE; } - /* Check and set other sampling flags */ - if (attr->config1 & PERF_CPUM_SF_FULL_BLOCKS) - SAMPL_FLAGS(hwc) |= PERF_CPUM_SF_FULL_BLOCKS; - - /* The sampling information (si) contains information about the - * min/max sampling intervals and the CPU speed. So calculate the - * correct sampling interval and avoid the whole period adjust - * feedback loop. - */ - rate = 0; - if (attr->freq) { - if (!attr->sample_freq) { - err = -EINVAL; - goto out; - } - rate = freq_to_sample_rate(&si, attr->sample_freq); - rate = hw_limit_rate(&si, rate); - attr->freq = 0; - attr->sample_period = rate; - } else { - /* The min/max sampling rates specifies the valid range - * of sample periods. If the specified sample period is - * out of range, limit the period to the range boundary. - */ - rate = hw_limit_rate(&si, hwc->sample_period); - - /* The perf core maintains a maximum sample rate that is - * configurable through the sysctl interface. Ensure the - * sampling rate does not exceed this value. This also helps - * to avoid throttling when pushing samples with - * perf_event_overflow(). - */ - if (sample_rate_to_freq(&si, rate) > - sysctl_perf_event_sample_rate) { - err = -EINVAL; - debug_sprintf_event(sfdbg, 1, "Sampling rate exceeds maximum perf sample rate\n"); - goto out; - } - } - SAMPL_RATE(hwc) = rate; - hw_init_period(hwc, SAMPL_RATE(hwc)); - - /* Initialize sample data overflow accounting */ - hwc->extra_reg.reg = REG_OVERFLOW; - OVERFLOW_REG(hwc) = 0; + err = __hw_perf_event_init_rate(event, &si); + if (err) + goto out; /* Use AUX buffer. No need to allocate it by ourself */ if (attr->config == PERF_EVENT_CPUM_SF_DIAG) - return 0; + goto out; /* Allocate the per-CPU sampling buffer using the CPU information * from the event. If the event is not pinned to a particular @@ -820,15 +832,25 @@ static int __hw_perf_event_init(struct perf_event *event) if (is_default_overflow_handler(event)) event->overflow_handler = cpumsf_output_event_pid; out: + mutex_unlock(&pmc_reserve_mutex); return err; } +static bool is_callchain_event(struct perf_event *event) +{ + u64 sample_type = event->attr.sample_type; + + return sample_type & (PERF_SAMPLE_CALLCHAIN | PERF_SAMPLE_REGS_USER | + PERF_SAMPLE_STACK_USER); +} + static int cpumsf_pmu_event_init(struct perf_event *event) { int err; /* No support for taken branch sampling */ - if (has_branch_stack(event)) + /* No support for callchain, stacks and registers */ + if (has_branch_stack(event) || is_callchain_event(event)) return -EOPNOTSUPP; switch (event->attr.type) { @@ -852,10 +874,6 @@ static int cpumsf_pmu_event_init(struct perf_event *event) return -ENOENT; } - /* Check online status of the CPU to which the event is pinned */ - if (event->cpu >= 0 && !cpu_online(event->cpu)) - return -ENODEV; - /* Force reset of idle/hv excludes regardless of what the * user requested. */ @@ -865,9 +883,6 @@ static int cpumsf_pmu_event_init(struct perf_event *event) event->attr.exclude_idle = 0; err = __hw_perf_event_init(event); - if (unlikely(err)) - if (event->destroy) - event->destroy(event); return err; } @@ -877,10 +892,14 @@ static void cpumsf_pmu_enable(struct pmu *pmu) struct hw_perf_event *hwc; int err; - if (cpuhw->flags & PMU_F_ENABLED) - return; - - if (cpuhw->flags & PMU_F_ERR_MASK) + /* + * Event must be + * - added/started on this CPU (PMU_F_IN_USE set) + * - and CPU must be available (PMU_F_RESERVED set) + * - and not already enabled (PMU_F_ENABLED not set) + * - and not in error condition (PMU_F_ERR_MASK not set) + */ + if (cpuhw->flags != (PMU_F_IN_USE | PMU_F_RESERVED)) return; /* Check whether to extent the sampling buffer. @@ -894,38 +913,27 @@ static void cpumsf_pmu_enable(struct pmu *pmu) * facility, but it can be fully re-enabled using sampling controls that * have been saved in cpumsf_pmu_disable(). */ - if (cpuhw->event) { - hwc = &cpuhw->event->hw; - if (!(SAMPL_DIAG_MODE(hwc))) { - /* - * Account number of overflow-designated - * buffer extents - */ - sfb_account_overflows(cpuhw, hwc); - if (sfb_has_pending_allocs(&cpuhw->sfb, hwc)) - extend_sampling_buffer(&cpuhw->sfb, hwc); - } + hwc = &cpuhw->event->hw; + if (!(SAMPL_DIAG_MODE(hwc))) { + /* + * Account number of overflow-designated buffer extents + */ + sfb_account_overflows(cpuhw, hwc); + extend_sampling_buffer(&cpuhw->sfb, hwc); } + /* Rate may be adjusted with ioctl() */ + cpuhw->lsctl.interval = SAMPL_RATE(hwc); /* (Re)enable the PMU and sampling facility */ - cpuhw->flags |= PMU_F_ENABLED; - barrier(); - err = lsctl(&cpuhw->lsctl); if (err) { - cpuhw->flags &= ~PMU_F_ENABLED; - pr_err("Loading sampling controls failed: op=%i err=%i\n", - 1, err); + pr_err("Loading sampling controls failed: op 1 err %i\n", err); return; } /* Load current program parameter */ - lpp(&S390_lowcore.lpp); - - debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i ed=%i cd=%i " - "tear=%p dear=%p\n", cpuhw->lsctl.es, cpuhw->lsctl.cs, - cpuhw->lsctl.ed, cpuhw->lsctl.cd, - (void *) cpuhw->lsctl.tear, (void *) cpuhw->lsctl.dear); + lpp(&get_lowcore()->lpp); + cpuhw->flags |= PMU_F_ENABLED; } static void cpumsf_pmu_disable(struct pmu *pmu) @@ -948,30 +956,27 @@ static void cpumsf_pmu_disable(struct pmu *pmu) err = lsctl(&inactive); if (err) { - pr_err("Loading sampling controls failed: op=%i err=%i\n", - 2, err); + pr_err("Loading sampling controls failed: op 2 err %i\n", err); return; } - /* Save state of TEAR and DEAR register contents */ - if (!qsi(&si)) { - /* TEAR/DEAR values are valid only if the sampling facility is - * enabled. Note that cpumsf_pmu_disable() might be called even - * for a disabled sampling facility because cpumsf_pmu_enable() - * controls the enable/disable state. - */ - if (si.es) { - cpuhw->lsctl.tear = si.tear; - cpuhw->lsctl.dear = si.dear; - } - } else - debug_sprintf_event(sfdbg, 3, "cpumsf_pmu_disable: " - "qsi() failed with err=%i\n", err); + /* + * Save state of TEAR and DEAR register contents. + * TEAR/DEAR values are valid only if the sampling facility is + * enabled. Note that cpumsf_pmu_disable() might be called even + * for a disabled sampling facility because cpumsf_pmu_enable() + * controls the enable/disable state. + */ + qsi(&si); + if (si.es) { + cpuhw->lsctl.tear = si.tear; + cpuhw->lsctl.dear = si.dear; + } cpuhw->flags &= ~PMU_F_ENABLED; } -/* perf_exclude_event() - Filter event +/* perf_event_exclude() - Filter event * @event: The perf event * @regs: pt_regs structure * @sde_regs: Sample-data-entry (sde) regs structure @@ -980,7 +985,7 @@ static void cpumsf_pmu_disable(struct pmu *pmu) * * Return non-zero if the event shall be excluded. */ -static int perf_exclude_event(struct perf_event *event, struct pt_regs *regs, +static int perf_event_exclude(struct perf_event *event, struct pt_regs *regs, struct perf_sf_sde_regs *sde_regs) { if (event->attr.exclude_user && user_mode(regs)) @@ -1063,12 +1068,9 @@ static int perf_push_sample(struct perf_event *event, data.tid_entry.pid = basic->hpp & LPP_PID_MASK; overflow = 0; - if (perf_exclude_event(event, ®s, sde_regs)) + if (perf_event_exclude(event, ®s, sde_regs)) goto out; - if (perf_event_overflow(event, &data, ®s)) { - overflow = 1; - event->pmu->stop(event, 0); - } + overflow = perf_event_overflow(event, &data, ®s); perf_event_update_userpage(event); out: return overflow; @@ -1079,14 +1081,6 @@ static void perf_event_count_update(struct perf_event *event, u64 count) local64_add(count, &event->count); } -static void debug_sample_entry(struct hws_basic_entry *sample, - struct hws_trailer_entry *te) -{ - debug_sprintf_event(sfdbg, 4, "hw_collect_samples: Found unknown " - "sampling data entry: te->f=%i basic.def=%04x (%p)\n", - te->f, sample->def, sample); -} - /* hw_collect_samples() - Walk through a sample-data-block and collect samples * @event: The perf event * @sdbt: Sample-data-block table @@ -1098,7 +1092,7 @@ static void debug_sample_entry(struct hws_basic_entry *sample, * combined-sampling data entry consists of a basic- and a diagnostic-sampling * data entry. The sampling function is determined by the flags in the perf * event hardware structure. The function always works with a combined-sampling - * data entry but ignores the the diagnostic portion if it is not available. + * data entry but ignores the diagnostic portion if it is not available. * * Note that the implementation focuses on basic-sampling data entries and, if * such an entry is not valid, the entire combined-sampling data entry is @@ -1113,11 +1107,11 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt, struct hws_trailer_entry *te; struct hws_basic_entry *sample; - te = (struct hws_trailer_entry *) trailer_entry_ptr(*sdbt); - sample = (struct hws_basic_entry *) *sdbt; - while ((unsigned long *) sample < (unsigned long *) te) { + te = trailer_entry_ptr((unsigned long)sdbt); + sample = (struct hws_basic_entry *)sdbt; + while ((unsigned long *)sample < (unsigned long *)te) { /* Check for an empty sample */ - if (!sample->def) + if (!sample->def || sample->LS) break; /* Update perf event period */ @@ -1140,7 +1134,6 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt, /* Count discarded samples */ *overflow += 1; } else { - debug_sample_entry(sample, te); /* Sample slot is not yet written or other record. * * This condition can occur if the buffer was reused @@ -1151,7 +1144,7 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt, * that are not full. Stop processing if the first * invalid format was detected. */ - if (!te->f) + if (!te->header.f) break; } @@ -1169,71 +1162,62 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt, * The sampling buffer position are retrieved and saved in the TEAR_REG * register of the specified perf event. * - * Only full sample-data-blocks are processed. Specify the flash_all flag - * to also walk through partially filled sample-data-blocks. It is ignored - * if PERF_CPUM_SF_FULL_BLOCKS is set. The PERF_CPUM_SF_FULL_BLOCKS flag - * enforces the processing of full sample-data-blocks only (trailer entries - * with the block-full-indicator bit set). + * Only full sample-data-blocks are processed. Specify the flush_all flag + * to also walk through partially filled sample-data-blocks. */ static void hw_perf_event_update(struct perf_event *event, int flush_all) { + unsigned long long event_overflow, sampl_overflow, num_sdb; struct hw_perf_event *hwc = &event->hw; + union hws_trailer_header prev, new; struct hws_trailer_entry *te; - unsigned long *sdbt; - unsigned long long event_overflow, sampl_overflow, num_sdb, te_flags; + unsigned long *sdbt, sdb; int done; /* * AUX buffer is used when in diagnostic sampling mode. * No perf events/samples are created. */ - if (SAMPL_DIAG_MODE(&event->hw)) + if (SAMPL_DIAG_MODE(hwc)) return; - if (flush_all && SDB_FULL_BLOCKS(hwc)) - flush_all = 0; - - sdbt = (unsigned long *) TEAR_REG(hwc); + sdbt = (unsigned long *)TEAR_REG(hwc); done = event_overflow = sampl_overflow = num_sdb = 0; while (!done) { /* Get the trailer entry of the sample-data-block */ - te = (struct hws_trailer_entry *) trailer_entry_ptr(*sdbt); + sdb = (unsigned long)phys_to_virt(*sdbt); + te = trailer_entry_ptr(sdb); /* Leave loop if no more work to do (block full indicator) */ - if (!te->f) { + if (!te->header.f) { done = 1; if (!flush_all) break; } /* Check the sample overflow count */ - if (te->overflow) + if (te->header.overflow) /* Account sample overflows and, if a particular limit * is reached, extend the sampling buffer. * For details, see sfb_account_overflows(). */ - sampl_overflow += te->overflow; - - /* Timestamps are valid for full sample-data-blocks only */ - debug_sprintf_event(sfdbg, 6, "hw_perf_event_update: sdbt=%p " - "overflow=%llu timestamp=0x%llx\n", - sdbt, te->overflow, - (te->f) ? trailer_timestamp(te) : 0ULL); + sampl_overflow += te->header.overflow; /* Collect all samples from a single sample-data-block and * flag if an (perf) event overflow happened. If so, the PMU * is stopped and remaining samples will be discarded. */ - hw_collect_samples(event, sdbt, &event_overflow); + hw_collect_samples(event, (unsigned long *)sdb, &event_overflow); num_sdb++; /* Reset trailer (using compare-double-and-swap) */ + prev.val = READ_ONCE_ALIGNED_128(te->header.val); do { - te_flags = te->flags & ~SDB_TE_BUFFER_FULL_MASK; - te_flags |= SDB_TE_ALERT_REQ_MASK; - } while (!cmpxchg_double(&te->flags, &te->overflow, - te->flags, te->overflow, - te_flags, 0ULL)); + new.val = prev.val; + new.f = 0; + new.a = 1; + new.overflow = 0; + } while (!try_cmpxchg128(&te->header.val, &prev.val, new.val)); /* Advance to next sample-data-block */ sdbt++; @@ -1241,35 +1225,52 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all) sdbt = get_next_sdbt(sdbt); /* Update event hardware registers */ - TEAR_REG(hwc) = (unsigned long) sdbt; + TEAR_REG(hwc) = (unsigned long)sdbt; /* Stop processing sample-data if all samples of the current * sample-data-block were flushed even if it was not full. */ if (flush_all && done) break; - - /* If an event overflow happened, discard samples by - * processing any remaining sample-data-blocks. - */ - if (event_overflow) - flush_all = 1; } /* Account sample overflows in the event hardware structure */ if (sampl_overflow) OVERFLOW_REG(hwc) = DIV_ROUND_UP(OVERFLOW_REG(hwc) + sampl_overflow, 1 + num_sdb); - if (sampl_overflow || event_overflow) - debug_sprintf_event(sfdbg, 4, "hw_perf_event_update: " - "overflow stats: sample=%llu event=%llu\n", - sampl_overflow, event_overflow); + + /* Perf_event_overflow() and perf_event_account_interrupt() limit + * the interrupt rate to an upper limit. Roughly 1000 samples per + * task tick. + * Hitting this limit results in a large number + * of throttled REF_REPORT_THROTTLE entries and the samples + * are dropped. + * Slightly increase the interval to avoid hitting this limit. + */ + if (event_overflow) + SAMPL_RATE(hwc) += DIV_ROUND_UP(SAMPL_RATE(hwc), 10); +} + +static inline unsigned long aux_sdb_index(struct aux_buffer *aux, + unsigned long i) +{ + return i % aux->sfb.num_sdb; } -#define AUX_SDB_INDEX(aux, i) ((i) % aux->sfb.num_sdb) -#define AUX_SDB_NUM(aux, start, end) (end >= start ? end - start + 1 : 0) -#define AUX_SDB_NUM_ALERT(aux) AUX_SDB_NUM(aux, aux->head, aux->alert_mark) -#define AUX_SDB_NUM_EMPTY(aux) AUX_SDB_NUM(aux, aux->head, aux->empty_mark) +static inline unsigned long aux_sdb_num(unsigned long start, unsigned long end) +{ + return end >= start ? end - start + 1 : 0; +} + +static inline unsigned long aux_sdb_num_alert(struct aux_buffer *aux) +{ + return aux_sdb_num(aux->head, aux->alert_mark); +} + +static inline unsigned long aux_sdb_num_empty(struct aux_buffer *aux) +{ + return aux_sdb_num(aux->head, aux->empty_mark); +} /* * Get trailer entry by index of SDB. @@ -1279,9 +1280,9 @@ static struct hws_trailer_entry *aux_sdb_trailer(struct aux_buffer *aux, { unsigned long sdb; - index = AUX_SDB_INDEX(aux, index); + index = aux_sdb_index(aux, index); sdb = aux->sdb_index[index]; - return (struct hws_trailer_entry *)trailer_entry_ptr(sdb); + return trailer_entry_ptr(sdb); } /* @@ -1303,10 +1304,10 @@ static void aux_output_end(struct perf_output_handle *handle) if (!aux) return; - range_scan = AUX_SDB_NUM_ALERT(aux); + range_scan = aux_sdb_num_alert(aux); for (i = 0, idx = aux->head; i < range_scan; i++, idx++) { te = aux_sdb_trailer(aux, idx); - if (!(te->flags & SDB_TE_BUFFER_FULL_MASK)) + if (!te->header.f) break; } /* i is num of SDBs which are full */ @@ -1314,9 +1315,7 @@ static void aux_output_end(struct perf_output_handle *handle) /* Remove alert indicators in the buffer */ te = aux_sdb_trailer(aux, aux->alert_mark); - te->flags &= ~SDB_TE_ALERT_REQ_MASK; - - debug_sprintf_event(sfdbg, 6, "aux_output_end: collect %lx SDBs\n", i); + te->header.a = 0; } /* @@ -1332,12 +1331,10 @@ static int aux_output_begin(struct perf_output_handle *handle, struct aux_buffer *aux, struct cpu_hw_sf *cpuhw) { - unsigned long range; - unsigned long i, range_scan, idx; - unsigned long head, base, offset; + unsigned long range, i, range_scan, idx, head, base, offset; struct hws_trailer_entry *te; - if (WARN_ON_ONCE(handle->head & ~PAGE_MASK)) + if (handle->head & ~PAGE_MASK) return -EINVAL; aux->head = handle->head >> PAGE_SHIFT; @@ -1349,14 +1346,14 @@ static int aux_output_begin(struct perf_output_handle *handle, * SDBs between aux->head and aux->empty_mark are already ready * for new data. range_scan is num of SDBs not within them. */ - if (range > AUX_SDB_NUM_EMPTY(aux)) { - range_scan = range - AUX_SDB_NUM_EMPTY(aux); + if (range > aux_sdb_num_empty(aux)) { + range_scan = range - aux_sdb_num_empty(aux); idx = aux->empty_mark + 1; for (i = 0; i < range_scan; i++, idx++) { te = aux_sdb_trailer(aux, idx); - te->flags = te->flags & ~SDB_TE_BUFFER_FULL_MASK; - te->flags = te->flags & ~SDB_TE_ALERT_REQ_MASK; - te->overflow = 0; + te->header.f = 0; + te->header.a = 0; + te->header.overflow = 0; } /* Save the position of empty SDBs */ aux->empty_mark = aux->head + range - 1; @@ -1365,24 +1362,14 @@ static int aux_output_begin(struct perf_output_handle *handle, /* Set alert indicator */ aux->alert_mark = aux->head + range/2 - 1; te = aux_sdb_trailer(aux, aux->alert_mark); - te->flags = te->flags | SDB_TE_ALERT_REQ_MASK; + te->header.a = 1; /* Reset hardware buffer head */ - head = AUX_SDB_INDEX(aux, aux->head); + head = aux_sdb_index(aux, aux->head); base = aux->sdbt_index[head / CPUM_SF_SDB_PER_TABLE]; offset = head % CPUM_SF_SDB_PER_TABLE; - cpuhw->lsctl.tear = base + offset * sizeof(unsigned long); - cpuhw->lsctl.dear = aux->sdb_index[head]; - - debug_sprintf_event(sfdbg, 6, "aux_output_begin: " - "head->alert_mark->empty_mark (num_alert, range)" - "[%lx -> %lx -> %lx] (%lx, %lx) " - "tear index %lx, tear %lx dear %lx\n", - aux->head, aux->alert_mark, aux->empty_mark, - AUX_SDB_NUM_ALERT(aux), range, - head / CPUM_SF_SDB_PER_TABLE, - cpuhw->lsctl.tear, - cpuhw->lsctl.dear); + cpuhw->lsctl.tear = virt_to_phys((void *)base) + offset * sizeof(unsigned long); + cpuhw->lsctl.dear = virt_to_phys((void *)aux->sdb_index[head]); return 0; } @@ -1396,15 +1383,15 @@ static int aux_output_begin(struct perf_output_handle *handle, static bool aux_set_alert(struct aux_buffer *aux, unsigned long alert_index, unsigned long long *overflow) { - unsigned long long orig_overflow, orig_flags, new_flags; + union hws_trailer_header prev, new; struct hws_trailer_entry *te; te = aux_sdb_trailer(aux, alert_index); + prev.val = READ_ONCE_ALIGNED_128(te->header.val); do { - orig_flags = te->flags; - orig_overflow = te->overflow; - *overflow = orig_overflow; - if (orig_flags & SDB_TE_BUFFER_FULL_MASK) { + new.val = prev.val; + *overflow = prev.overflow; + if (prev.f) { /* * SDB is already set by hardware. * Abort and try to set somewhere @@ -1412,10 +1399,9 @@ static bool aux_set_alert(struct aux_buffer *aux, unsigned long alert_index, */ return false; } - new_flags = orig_flags | SDB_TE_ALERT_REQ_MASK; - } while (!cmpxchg_double(&te->flags, &te->overflow, - orig_flags, orig_overflow, - new_flags, 0ULL)); + new.a = 1; + new.overflow = 0; + } while (!try_cmpxchg128(&te->header.val, &prev.val, new.val)); return true; } @@ -1444,11 +1430,12 @@ static bool aux_set_alert(struct aux_buffer *aux, unsigned long alert_index, static bool aux_reset_buffer(struct aux_buffer *aux, unsigned long range, unsigned long long *overflow) { - unsigned long long orig_overflow, orig_flags, new_flags; + union hws_trailer_header prev, new; unsigned long i, range_scan, idx; + unsigned long long orig_overflow; struct hws_trailer_entry *te; - if (range <= AUX_SDB_NUM_EMPTY(aux)) + if (range <= aux_sdb_num_empty(aux)) /* * No need to scan. All SDBs in range are marked as empty. * Just set alert indicator. Should check race with hardware @@ -1469,21 +1456,21 @@ static bool aux_reset_buffer(struct aux_buffer *aux, unsigned long range, * Start scanning from one SDB behind empty_mark. If the new alert * indicator fall into this range, set it. */ - range_scan = range - AUX_SDB_NUM_EMPTY(aux); + range_scan = range - aux_sdb_num_empty(aux); idx = aux->empty_mark + 1; for (i = 0; i < range_scan; i++, idx++) { te = aux_sdb_trailer(aux, idx); + prev.val = READ_ONCE_ALIGNED_128(te->header.val); do { - orig_flags = te->flags; - orig_overflow = te->overflow; - new_flags = orig_flags & ~SDB_TE_BUFFER_FULL_MASK; + new.val = prev.val; + orig_overflow = prev.overflow; + new.f = 0; + new.overflow = 0; if (idx == aux->alert_mark) - new_flags |= SDB_TE_ALERT_REQ_MASK; + new.a = 1; else - new_flags &= ~SDB_TE_ALERT_REQ_MASK; - } while (!cmpxchg_double(&te->flags, &te->overflow, - orig_flags, orig_overflow, - new_flags, 0ULL)); + new.a = 0; + } while (!try_cmpxchg128(&te->header.val, &prev.val, new.val)); *overflow += orig_overflow; } @@ -1506,14 +1493,16 @@ static void hw_collect_aux(struct cpu_hw_sf *cpuhw) unsigned long num_sdb; aux = perf_get_aux(handle); - if (WARN_ON_ONCE(!aux)) + if (!aux) return; /* Inform user space new data arrived */ - size = AUX_SDB_NUM_ALERT(aux) << PAGE_SHIFT; + size = aux_sdb_num_alert(aux) << PAGE_SHIFT; + debug_sprintf_event(sfdbg, 6, "%s #alert %ld\n", __func__, + size >> PAGE_SHIFT); perf_aux_output_end(handle, size); - num_sdb = aux->sfb.num_sdb; + num_sdb = aux->sfb.num_sdb; while (!done) { /* Get an output handle */ aux = perf_aux_output_begin(handle, cpuhw->event); @@ -1521,10 +1510,9 @@ static void hw_collect_aux(struct cpu_hw_sf *cpuhw) pr_err("The AUX buffer with %lu pages for the " "diagnostic-sampling mode is full\n", num_sdb); - debug_sprintf_event(sfdbg, 1, "AUX buffer used up\n"); break; } - if (WARN_ON_ONCE(!aux)) + if (!aux) return; /* Update head and alert_mark to new position */ @@ -1543,24 +1531,12 @@ static void hw_collect_aux(struct cpu_hw_sf *cpuhw) size = range << PAGE_SHIFT; perf_aux_output_end(&cpuhw->handle, size); pr_err("Sample data caused the AUX buffer with %lu " - "pages to overflow\n", num_sdb); - debug_sprintf_event(sfdbg, 1, "head %lx range %lx " - "overflow %llx\n", - aux->head, range, overflow); + "pages to overflow\n", aux->sfb.num_sdb); } else { - size = AUX_SDB_NUM_ALERT(aux) << PAGE_SHIFT; + size = aux_sdb_num_alert(aux) << PAGE_SHIFT; perf_aux_output_end(&cpuhw->handle, size); - debug_sprintf_event(sfdbg, 6, "head %lx alert %lx " - "already full, try another\n", - aux->head, aux->alert_mark); } } - - if (done) - debug_sprintf_event(sfdbg, 6, "aux_reset_buffer: " - "[%lx -> %lx -> %lx] (%lx, %lx)\n", - aux->head, aux->alert_mark, aux->empty_mark, - AUX_SDB_NUM_ALERT(aux), range); } /* @@ -1582,25 +1558,22 @@ static void aux_buffer_free(void *data) kfree(aux->sdbt_index); kfree(aux->sdb_index); kfree(aux); - - debug_sprintf_event(sfdbg, 4, "aux_buffer_free: free " - "%lu SDBTs\n", num_sdbt); } static void aux_sdb_init(unsigned long sdb) { struct hws_trailer_entry *te; - te = (struct hws_trailer_entry *)trailer_entry_ptr(sdb); + te = trailer_entry_ptr(sdb); /* Save clock base */ te->clock_base = 1; - memcpy(&te->progusage2, &tod_clock_base[1], 8); + te->progusage2 = tod_clock_base.tod; } /* * aux_buffer_setup() - Setup AUX buffer for diagnostic mode sampling - * @cpu: On which to allocate, -1 means current + * @event: Event the buffer is setup for, event->cpu == -1 means current * @pages: Array of pointers to buffer pages passed from perf core * @nr_pages: Total pages * @snapshot: Flag for snapshot mode @@ -1612,8 +1585,8 @@ static void aux_sdb_init(unsigned long sdb) * * Return the private AUX buffer structure if success or NULL if fails. */ -static void *aux_buffer_setup(int cpu, void **pages, int nr_pages, - bool snapshot) +static void *aux_buffer_setup(struct perf_event *event, void **pages, + int nr_pages, bool snapshot) { struct sf_buffer *sfb; struct aux_buffer *aux; @@ -1636,13 +1609,13 @@ static void *aux_buffer_setup(int cpu, void **pages, int nr_pages, } /* Allocate aux_buffer struct for the event */ - aux = kmalloc(sizeof(struct aux_buffer), GFP_KERNEL); + aux = kzalloc(sizeof(struct aux_buffer), GFP_KERNEL); if (!aux) goto no_aux; sfb = &aux->sfb; /* Allocate sdbt_index for fast reference */ - n_sdbt = (nr_pages + CPUM_SF_SDB_PER_TABLE - 1) / CPUM_SF_SDB_PER_TABLE; + n_sdbt = DIV_ROUND_UP(nr_pages, CPUM_SF_SDB_PER_TABLE); aux->sdbt_index = kmalloc_array(n_sdbt, sizeof(void *), GFP_KERNEL); if (!aux->sdbt_index) goto no_sdbt_index; @@ -1654,7 +1627,7 @@ static void *aux_buffer_setup(int cpu, void **pages, int nr_pages, /* Allocate the first SDBT */ sfb->num_sdbt = 0; - sfb->sdbt = (unsigned long *) get_zeroed_page(GFP_KERNEL); + sfb->sdbt = (unsigned long *)get_zeroed_page(GFP_KERNEL); if (!sfb->sdbt) goto no_sdbt; aux->sdbt_index[sfb->num_sdbt++] = (unsigned long)sfb->sdbt; @@ -1666,23 +1639,23 @@ static void *aux_buffer_setup(int cpu, void **pages, int nr_pages, */ for (i = 0; i < nr_pages; i++, tail++) { if (require_table_link(tail)) { - new = (unsigned long *) get_zeroed_page(GFP_KERNEL); + new = (unsigned long *)get_zeroed_page(GFP_KERNEL); if (!new) goto no_sdbt; aux->sdbt_index[sfb->num_sdbt++] = (unsigned long)new; /* Link current page to tail of chain */ - *tail = (unsigned long)(void *) new + 1; + *tail = virt_to_phys(new) + 1; tail = new; } /* Tail is the entry in a SDBT */ - *tail = (unsigned long)pages[i]; + *tail = virt_to_phys(pages[i]); aux->sdb_index[i] = (unsigned long)pages[i]; aux_sdb_init((unsigned long)pages[i]); } sfb->num_sdb = nr_pages; /* Link the last entry in the SDBT to the first SDBT */ - *tail = (unsigned long) sfb->sdbt + 1; + *tail = virt_to_phys(sfb->sdbt) + 1; sfb->tail = tail; /* @@ -1692,10 +1665,6 @@ static void *aux_buffer_setup(int cpu, void **pages, int nr_pages, */ aux->empty_mark = sfb->num_sdb - 1; - debug_sprintf_event(sfdbg, 4, "aux_buffer_setup: setup %lu SDBTs" - " and %lu SDBs\n", - sfb->num_sdbt, sfb->num_sdb); - return aux; no_sdbt: @@ -1716,6 +1685,39 @@ static void cpumsf_pmu_read(struct perf_event *event) /* Nothing to do ... updates are interrupt-driven */ } +/* Check if the new sampling period/frequency is appropriate. + * + * Return non-zero on error and zero on passed checks. + */ +static int cpumsf_pmu_check_period(struct perf_event *event, u64 value) +{ + struct hws_qsi_info_block si; + unsigned long rate; + bool do_freq; + + memset(&si, 0, sizeof(si)); + if (event->cpu == -1) { + qsi(&si); + } else { + /* Event is pinned to a particular CPU, retrieve the per-CPU + * sampling structure for accessing the CPU-specific QSI. + */ + struct cpu_hw_sf *cpuhw = &per_cpu(cpu_hw_sf, event->cpu); + + si = cpuhw->qsi; + } + + do_freq = !!SAMPL_FREQ_MODE(&event->hw); + rate = getrate(do_freq, value, &si); + if (!rate) + return -EINVAL; + + event->attr.sample_period = rate; + SAMPL_RATE(&event->hw) = rate; + hw_init_period(&event->hw, SAMPL_RATE(&event->hw)); + return 0; +} + /* Activate sampling control. * Next call of pmu_enable() starts sampling. */ @@ -1723,12 +1725,8 @@ static void cpumsf_pmu_start(struct perf_event *event, int flags) { struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf); - if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED))) + if (!(event->hw.state & PERF_HES_STOPPED)) return; - - if (flags & PERF_EF_RELOAD) - WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE)); - perf_pmu_disable(event->pmu); event->hw.state = 0; cpuhw->lsctl.cs = 1; @@ -1753,7 +1751,9 @@ static void cpumsf_pmu_stop(struct perf_event *event, int flags) event->hw.state |= PERF_HES_STOPPED; if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) { - hw_perf_event_update(event, 1); + /* CPU hotplug off removes SDBs. No samples to extract. */ + if (cpuhw->flags & PMU_F_RESERVED) + hw_perf_event_update(event, 1); event->hw.state |= PERF_HES_UPTODATE; } perf_pmu_enable(event->pmu); @@ -1763,15 +1763,14 @@ static int cpumsf_pmu_add(struct perf_event *event, int flags) { struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf); struct aux_buffer *aux; - int err; + int err = 0; if (cpuhw->flags & PMU_F_IN_USE) return -EAGAIN; - if (!SAMPL_DIAG_MODE(&event->hw) && !cpuhw->sfb.sdbt) + if (!SAMPL_DIAG_MODE(&event->hw) && !sf_buffer_available(cpuhw)) return -EINVAL; - err = 0; perf_pmu_disable(event->pmu); event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED; @@ -1785,9 +1784,9 @@ static int cpumsf_pmu_add(struct perf_event *event, int flags) cpuhw->lsctl.h = 1; cpuhw->lsctl.interval = SAMPL_RATE(&event->hw); if (!SAMPL_DIAG_MODE(&event->hw)) { - cpuhw->lsctl.tear = (unsigned long) cpuhw->sfb.sdbt; - cpuhw->lsctl.dear = *(unsigned long *) cpuhw->sfb.sdbt; - hw_reset_registers(&event->hw, cpuhw->sfb.sdbt); + cpuhw->lsctl.tear = virt_to_phys(cpuhw->sfb.sdbt); + cpuhw->lsctl.dear = *(unsigned long *)cpuhw->sfb.sdbt; + TEAR_REG(&event->hw) = (unsigned long)cpuhw->sfb.sdbt; } /* Ensure sampling functions are in the disabled state. If disabled, @@ -1879,10 +1878,12 @@ static struct attribute_group cpumsf_pmu_events_group = { .name = "events", .attrs = cpumsf_pmu_events_attr, }; + static struct attribute_group cpumsf_pmu_format_group = { .name = "format", .attrs = cpumsf_pmu_format_attr, }; + static const struct attribute_group *cpumsf_pmu_attr_groups[] = { &cpumsf_pmu_events_group, &cpumsf_pmu_format_group, @@ -1905,6 +1906,8 @@ static struct pmu cpumf_sampling = { .setup_aux = aux_buffer_setup, .free_aux = aux_buffer_free, + + .check_period = cpumsf_pmu_check_period, }; static void cpumf_measurement_alert(struct ext_code ext_code, @@ -1927,18 +1930,18 @@ static void cpumf_measurement_alert(struct ext_code ext_code, /* Program alert request */ if (alert & CPU_MF_INT_SF_PRA) { - if (cpuhw->flags & PMU_F_IN_USE) + if (cpuhw->flags & PMU_F_IN_USE) { if (SAMPL_DIAG_MODE(&cpuhw->event->hw)) hw_collect_aux(cpuhw); else hw_perf_event_update(cpuhw->event, 0); - else - WARN_ON_ONCE(!(cpuhw->flags & PMU_F_IN_USE)); + } } /* Report measurement alerts only for non-PRA codes */ if (alert != CPU_MF_INT_SF_PRA) - debug_sprintf_event(sfdbg, 6, "measurement alert: 0x%x\n", alert); + debug_sprintf_event(sfdbg, 6, "%s alert %#x\n", __func__, + alert); /* Sampling authorization change request */ if (alert & CPU_MF_INT_SF_SACA) @@ -1953,18 +1956,19 @@ static void cpumf_measurement_alert(struct ext_code ext_code, /* Invalid sampling buffer entry */ if (alert & (CPU_MF_INT_SF_IAE|CPU_MF_INT_SF_ISE)) { - pr_err("A sampling buffer entry is incorrect (alert=0x%x)\n", + pr_err("A sampling buffer entry is incorrect (alert=%#x)\n", alert); cpuhw->flags |= PMU_F_ERR_IBE; sf_disable(); } } + static int cpusf_pmu_setup(unsigned int cpu, int flags) { /* Ignore the notification if no events are scheduled on the PMU. * This might be racy... */ - if (!atomic_read(&num_events)) + if (!refcount_read(&num_events)) return 0; local_irq_disable(); @@ -2015,7 +2019,7 @@ static int param_set_sfb_size(const char *val, const struct kernel_param *kp) sfb_set_limits(min, max); pr_info("The sampling buffer limits have changed to: " - "min=%lu max=%lu (diag=x%lu)\n", + "min %lu max %lu (diag %lu)\n", CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB, CPUM_SF_SDB_DIAG_FACTOR); return 0; } @@ -2026,14 +2030,16 @@ static const struct kernel_param_ops param_ops_sfb_size = { .get = param_get_sfb_size, }; -#define RS_INIT_FAILURE_QSI 0x0001 -#define RS_INIT_FAILURE_BSDES 0x0002 -#define RS_INIT_FAILURE_ALRT 0x0003 -#define RS_INIT_FAILURE_PERF 0x0004 +enum { + RS_INIT_FAILURE_BSDES = 2, /* Bad basic sampling size */ + RS_INIT_FAILURE_ALRT = 3, /* IRQ registration failure */ + RS_INIT_FAILURE_PERF = 4 /* PMU registration failure */ +}; + static void __init pr_cpumsf_err(unsigned int reason) { pr_err("Sampling facility support for perf is not available: " - "reason=%04x\n", reason); + "reason %#x\n", reason); } static int __init init_cpum_sampling_pmu(void) @@ -2045,11 +2051,7 @@ static int __init init_cpum_sampling_pmu(void) return -ENODEV; memset(&si, 0, sizeof(si)); - if (qsi(&si)) { - pr_cpumsf_err(RS_INIT_FAILURE_QSI); - return -ENODEV; - } - + qsi(&si); if (!si.as && !si.ad) return -ENODEV; @@ -2067,7 +2069,7 @@ static int __init init_cpum_sampling_pmu(void) CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC_DIAG); } - sfdbg = debug_register(KMSG_COMPONENT, 2, 1, 80); + sfdbg = debug_register("cpum_sf", 2, 1, 80); if (!sfdbg) { pr_err("Registering for s390dbf failed\n"); return -ENOMEM; @@ -2096,5 +2098,6 @@ static int __init init_cpum_sampling_pmu(void) out: return err; } + arch_initcall(init_cpum_sampling_pmu); -core_param(cpum_sfb_size, CPUM_SF_MAX_SDB, sfb_size, 0640); +core_param(cpum_sfb_size, CPUM_SF_MAX_SDB, sfb_size, 0644); |