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2231 lines
63 KiB
2231 lines
63 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Performance event support for the System z CPU-measurement Sampling Facility |
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* |
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* Copyright IBM Corp. 2013, 2018 |
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* Author(s): Hendrik Brueckner <[email protected]> |
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*/ |
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#define KMSG_COMPONENT "cpum_sf" |
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
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|
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#include <linux/kernel.h> |
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#include <linux/kernel_stat.h> |
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#include <linux/perf_event.h> |
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#include <linux/percpu.h> |
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#include <linux/pid.h> |
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#include <linux/notifier.h> |
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#include <linux/export.h> |
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#include <linux/slab.h> |
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#include <linux/mm.h> |
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#include <linux/moduleparam.h> |
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#include <asm/cpu_mf.h> |
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#include <asm/irq.h> |
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#include <asm/debug.h> |
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#include <asm/timex.h> |
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|
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/* Minimum number of sample-data-block-tables: |
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* At least one table is required for the sampling buffer structure. |
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* A single table contains up to 511 pointers to sample-data-blocks. |
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*/ |
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#define CPUM_SF_MIN_SDBT 1 |
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|
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/* Number of sample-data-blocks per sample-data-block-table (SDBT): |
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* A table contains SDB pointers (8 bytes) and one table-link entry |
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* that points to the origin of the next SDBT. |
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*/ |
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#define CPUM_SF_SDB_PER_TABLE ((PAGE_SIZE - 8) / 8) |
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|
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/* Maximum page offset for an SDBT table-link entry: |
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* If this page offset is reached, a table-link entry to the next SDBT |
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* must be added. |
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*/ |
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#define CPUM_SF_SDBT_TL_OFFSET (CPUM_SF_SDB_PER_TABLE * 8) |
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static inline int require_table_link(const void *sdbt) |
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{ |
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return ((unsigned long) sdbt & ~PAGE_MASK) == CPUM_SF_SDBT_TL_OFFSET; |
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} |
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|
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/* Minimum and maximum sampling buffer sizes: |
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* |
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* This number represents the maximum size of the sampling buffer taking |
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* the number of sample-data-block-tables into account. Note that these |
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* numbers apply to the basic-sampling function only. |
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* The maximum number of SDBs is increased by CPUM_SF_SDB_DIAG_FACTOR if |
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* the diagnostic-sampling function is active. |
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* |
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* Sampling buffer size Buffer characteristics |
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* --------------------------------------------------- |
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* 64KB == 16 pages (4KB per page) |
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* 1 page for SDB-tables |
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* 15 pages for SDBs |
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* |
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* 32MB == 8192 pages (4KB per page) |
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* 16 pages for SDB-tables |
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* 8176 pages for SDBs |
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*/ |
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static unsigned long __read_mostly CPUM_SF_MIN_SDB = 15; |
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static unsigned long __read_mostly CPUM_SF_MAX_SDB = 8176; |
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static unsigned long __read_mostly CPUM_SF_SDB_DIAG_FACTOR = 1; |
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|
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struct sf_buffer { |
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unsigned long *sdbt; /* Sample-data-block-table origin */ |
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/* buffer characteristics (required for buffer increments) */ |
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unsigned long num_sdb; /* Number of sample-data-blocks */ |
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unsigned long num_sdbt; /* Number of sample-data-block-tables */ |
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unsigned long *tail; /* last sample-data-block-table */ |
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}; |
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|
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struct aux_buffer { |
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struct sf_buffer sfb; |
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unsigned long head; /* index of SDB of buffer head */ |
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unsigned long alert_mark; /* index of SDB of alert request position */ |
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unsigned long empty_mark; /* mark of SDB not marked full */ |
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unsigned long *sdb_index; /* SDB address for fast lookup */ |
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unsigned long *sdbt_index; /* SDBT address for fast lookup */ |
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}; |
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|
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struct cpu_hw_sf { |
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/* CPU-measurement sampling information block */ |
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struct hws_qsi_info_block qsi; |
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/* CPU-measurement sampling control block */ |
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struct hws_lsctl_request_block lsctl; |
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struct sf_buffer sfb; /* Sampling buffer */ |
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unsigned int flags; /* Status flags */ |
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struct perf_event *event; /* Scheduled perf event */ |
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struct perf_output_handle handle; /* AUX buffer output handle */ |
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}; |
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static DEFINE_PER_CPU(struct cpu_hw_sf, cpu_hw_sf); |
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|
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/* Debug feature */ |
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static debug_info_t *sfdbg; |
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|
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/* |
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* sf_disable() - Switch off sampling facility |
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*/ |
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static int sf_disable(void) |
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{ |
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struct hws_lsctl_request_block sreq; |
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|
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memset(&sreq, 0, sizeof(sreq)); |
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return lsctl(&sreq); |
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} |
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|
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/* |
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* sf_buffer_available() - Check for an allocated sampling buffer |
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*/ |
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static int sf_buffer_available(struct cpu_hw_sf *cpuhw) |
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{ |
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return !!cpuhw->sfb.sdbt; |
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} |
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|
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/* |
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* deallocate sampling facility buffer |
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*/ |
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static void free_sampling_buffer(struct sf_buffer *sfb) |
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{ |
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unsigned long *sdbt, *curr; |
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|
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if (!sfb->sdbt) |
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return; |
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sdbt = sfb->sdbt; |
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curr = sdbt; |
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|
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/* Free the SDBT after all SDBs are processed... */ |
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while (1) { |
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if (!*curr || !sdbt) |
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break; |
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|
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/* Process table-link entries */ |
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if (is_link_entry(curr)) { |
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curr = get_next_sdbt(curr); |
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if (sdbt) |
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free_page((unsigned long) sdbt); |
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|
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/* If the origin is reached, sampling buffer is freed */ |
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if (curr == sfb->sdbt) |
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break; |
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else |
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sdbt = curr; |
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} else { |
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/* Process SDB pointer */ |
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if (*curr) { |
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free_page(*curr); |
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curr++; |
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} |
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} |
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} |
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debug_sprintf_event(sfdbg, 5, "%s: freed sdbt %#lx\n", __func__, |
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(unsigned long)sfb->sdbt); |
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memset(sfb, 0, sizeof(*sfb)); |
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} |
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|
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static int alloc_sample_data_block(unsigned long *sdbt, gfp_t gfp_flags) |
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{ |
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unsigned long sdb, *trailer; |
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|
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/* Allocate and initialize sample-data-block */ |
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sdb = get_zeroed_page(gfp_flags); |
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if (!sdb) |
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return -ENOMEM; |
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trailer = trailer_entry_ptr(sdb); |
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*trailer = SDB_TE_ALERT_REQ_MASK; |
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|
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/* Link SDB into the sample-data-block-table */ |
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*sdbt = sdb; |
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|
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return 0; |
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} |
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|
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/* |
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* realloc_sampling_buffer() - extend sampler memory |
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* |
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* Allocates new sample-data-blocks and adds them to the specified sampling |
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* buffer memory. |
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* |
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* Important: This modifies the sampling buffer and must be called when the |
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* sampling facility is disabled. |
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* |
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* Returns zero on success, non-zero otherwise. |
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*/ |
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static int realloc_sampling_buffer(struct sf_buffer *sfb, |
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unsigned long num_sdb, gfp_t gfp_flags) |
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{ |
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int i, rc; |
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unsigned long *new, *tail, *tail_prev = NULL; |
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|
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if (!sfb->sdbt || !sfb->tail) |
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return -EINVAL; |
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|
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if (!is_link_entry(sfb->tail)) |
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return -EINVAL; |
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|
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/* Append to the existing sampling buffer, overwriting the table-link |
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* register. |
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* The tail variables always points to the "tail" (last and table-link) |
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* entry in an SDB-table. |
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*/ |
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tail = sfb->tail; |
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|
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/* Do a sanity check whether the table-link entry points to |
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* the sampling buffer origin. |
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*/ |
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if (sfb->sdbt != get_next_sdbt(tail)) { |
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debug_sprintf_event(sfdbg, 3, "%s: " |
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"sampling buffer is not linked: origin %#lx" |
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" tail %#lx\n", __func__, |
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(unsigned long)sfb->sdbt, |
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(unsigned long)tail); |
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return -EINVAL; |
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} |
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|
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/* Allocate remaining SDBs */ |
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rc = 0; |
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for (i = 0; i < num_sdb; i++) { |
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/* Allocate a new SDB-table if it is full. */ |
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if (require_table_link(tail)) { |
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new = (unsigned long *) get_zeroed_page(gfp_flags); |
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if (!new) { |
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rc = -ENOMEM; |
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break; |
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} |
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sfb->num_sdbt++; |
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/* Link current page to tail of chain */ |
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*tail = (unsigned long)(void *) new + 1; |
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tail_prev = tail; |
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tail = new; |
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} |
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|
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/* Allocate a new sample-data-block. |
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* If there is not enough memory, stop the realloc process |
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* and simply use what was allocated. If this is a temporary |
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* issue, a new realloc call (if required) might succeed. |
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*/ |
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rc = alloc_sample_data_block(tail, gfp_flags); |
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if (rc) { |
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/* Undo last SDBT. An SDBT with no SDB at its first |
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* entry but with an SDBT entry instead can not be |
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* handled by the interrupt handler code. |
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* Avoid this situation. |
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*/ |
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if (tail_prev) { |
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sfb->num_sdbt--; |
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free_page((unsigned long) new); |
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tail = tail_prev; |
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} |
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break; |
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} |
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sfb->num_sdb++; |
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tail++; |
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tail_prev = new = NULL; /* Allocated at least one SBD */ |
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} |
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|
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/* Link sampling buffer to its origin */ |
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*tail = (unsigned long) sfb->sdbt + 1; |
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sfb->tail = tail; |
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|
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debug_sprintf_event(sfdbg, 4, "%s: new buffer" |
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" settings: sdbt %lu sdb %lu\n", __func__, |
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sfb->num_sdbt, sfb->num_sdb); |
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return rc; |
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} |
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|
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/* |
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* allocate_sampling_buffer() - allocate sampler memory |
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* |
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* Allocates and initializes a sampling buffer structure using the |
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* specified number of sample-data-blocks (SDB). For each allocation, |
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* a 4K page is used. The number of sample-data-block-tables (SDBT) |
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* are calculated from SDBs. |
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* Also set the ALERT_REQ mask in each SDBs trailer. |
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* |
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* Returns zero on success, non-zero otherwise. |
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*/ |
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static int alloc_sampling_buffer(struct sf_buffer *sfb, unsigned long num_sdb) |
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{ |
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int rc; |
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|
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if (sfb->sdbt) |
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return -EINVAL; |
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|
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/* Allocate the sample-data-block-table origin */ |
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sfb->sdbt = (unsigned long *) get_zeroed_page(GFP_KERNEL); |
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if (!sfb->sdbt) |
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return -ENOMEM; |
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sfb->num_sdb = 0; |
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sfb->num_sdbt = 1; |
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|
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/* Link the table origin to point to itself to prepare for |
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* realloc_sampling_buffer() invocation. |
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*/ |
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sfb->tail = sfb->sdbt; |
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*sfb->tail = (unsigned long)(void *) sfb->sdbt + 1; |
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|
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/* Allocate requested number of sample-data-blocks */ |
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rc = realloc_sampling_buffer(sfb, num_sdb, GFP_KERNEL); |
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if (rc) { |
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free_sampling_buffer(sfb); |
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debug_sprintf_event(sfdbg, 4, "%s: " |
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"realloc_sampling_buffer failed with rc %i\n", |
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__func__, rc); |
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} else |
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debug_sprintf_event(sfdbg, 4, |
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"%s: tear %#lx dear %#lx\n", __func__, |
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(unsigned long)sfb->sdbt, (unsigned long)*sfb->sdbt); |
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return rc; |
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} |
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static void sfb_set_limits(unsigned long min, unsigned long max) |
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{ |
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struct hws_qsi_info_block si; |
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CPUM_SF_MIN_SDB = min; |
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CPUM_SF_MAX_SDB = max; |
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memset(&si, 0, sizeof(si)); |
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if (!qsi(&si)) |
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CPUM_SF_SDB_DIAG_FACTOR = DIV_ROUND_UP(si.dsdes, si.bsdes); |
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} |
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|
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static unsigned long sfb_max_limit(struct hw_perf_event *hwc) |
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{ |
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return SAMPL_DIAG_MODE(hwc) ? CPUM_SF_MAX_SDB * CPUM_SF_SDB_DIAG_FACTOR |
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: CPUM_SF_MAX_SDB; |
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} |
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static unsigned long sfb_pending_allocs(struct sf_buffer *sfb, |
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struct hw_perf_event *hwc) |
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{ |
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if (!sfb->sdbt) |
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return SFB_ALLOC_REG(hwc); |
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if (SFB_ALLOC_REG(hwc) > sfb->num_sdb) |
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return SFB_ALLOC_REG(hwc) - sfb->num_sdb; |
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return 0; |
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} |
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|
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static int sfb_has_pending_allocs(struct sf_buffer *sfb, |
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struct hw_perf_event *hwc) |
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{ |
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return sfb_pending_allocs(sfb, hwc) > 0; |
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} |
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|
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static void sfb_account_allocs(unsigned long num, struct hw_perf_event *hwc) |
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{ |
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/* Limit the number of SDBs to not exceed the maximum */ |
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num = min_t(unsigned long, num, sfb_max_limit(hwc) - SFB_ALLOC_REG(hwc)); |
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if (num) |
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SFB_ALLOC_REG(hwc) += num; |
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} |
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|
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static void sfb_init_allocs(unsigned long num, struct hw_perf_event *hwc) |
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{ |
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SFB_ALLOC_REG(hwc) = 0; |
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sfb_account_allocs(num, hwc); |
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} |
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|
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static void deallocate_buffers(struct cpu_hw_sf *cpuhw) |
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{ |
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if (cpuhw->sfb.sdbt) |
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free_sampling_buffer(&cpuhw->sfb); |
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} |
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|
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static int allocate_buffers(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc) |
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{ |
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unsigned long n_sdb, freq; |
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size_t sample_size; |
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|
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/* Calculate sampling buffers using 4K pages |
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* |
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* 1. The sampling size is 32 bytes for basic sampling. This size |
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* is the same for all machine types. Diagnostic |
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* sampling uses auxlilary data buffer setup which provides the |
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* memory for SDBs using linux common code auxiliary trace |
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* setup. |
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* |
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* 2. Function alloc_sampling_buffer() sets the Alert Request |
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* Control indicator to trigger a measurement-alert to harvest |
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* sample-data-blocks (SDB). This is done per SDB. This |
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* measurement alert interrupt fires quick enough to handle |
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* one SDB, on very high frequency and work loads there might |
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* be 2 to 3 SBDs available for sample processing. |
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* Currently there is no need for setup alert request on every |
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* n-th page. This is counterproductive as one IRQ triggers |
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* a very high number of samples to be processed at one IRQ. |
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* |
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* 3. Use the sampling frequency as input. |
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* Compute the number of SDBs and ensure a minimum |
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* of CPUM_SF_MIN_SDB. Depending on frequency add some more |
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* SDBs to handle a higher sampling rate. |
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* Use a minimum of CPUM_SF_MIN_SDB and allow for 100 samples |
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* (one SDB) for every 10000 HZ frequency increment. |
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* |
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* 4. Compute the number of sample-data-block-tables (SDBT) and |
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* ensure a minimum of CPUM_SF_MIN_SDBT (one table can manage up |
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* to 511 SDBs). |
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*/ |
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sample_size = sizeof(struct hws_basic_entry); |
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freq = sample_rate_to_freq(&cpuhw->qsi, SAMPL_RATE(hwc)); |
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n_sdb = CPUM_SF_MIN_SDB + DIV_ROUND_UP(freq, 10000); |
|
|
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/* If there is already a sampling buffer allocated, it is very likely |
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* that the sampling facility is enabled too. If the event to be |
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* initialized requires a greater sampling buffer, the allocation must |
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* be postponed. Changing the sampling buffer requires the sampling |
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* facility to be in the disabled state. So, account the number of |
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* required SDBs and let cpumsf_pmu_enable() resize the buffer just |
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* before the event is started. |
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*/ |
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sfb_init_allocs(n_sdb, hwc); |
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if (sf_buffer_available(cpuhw)) |
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return 0; |
|
|
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debug_sprintf_event(sfdbg, 3, |
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"%s: rate %lu f %lu sdb %lu/%lu" |
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" sample_size %lu cpuhw %p\n", __func__, |
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SAMPL_RATE(hwc), freq, n_sdb, sfb_max_limit(hwc), |
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sample_size, cpuhw); |
|
|
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return alloc_sampling_buffer(&cpuhw->sfb, |
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sfb_pending_allocs(&cpuhw->sfb, hwc)); |
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} |
|
|
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static unsigned long min_percent(unsigned int percent, unsigned long base, |
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unsigned long min) |
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{ |
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return min_t(unsigned long, min, DIV_ROUND_UP(percent * base, 100)); |
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} |
|
|
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static unsigned long compute_sfb_extent(unsigned long ratio, unsigned long base) |
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{ |
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/* Use a percentage-based approach to extend the sampling facility |
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* buffer. Accept up to 5% sample data loss. |
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* Vary the extents between 1% to 5% of the current number of |
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* sample-data-blocks. |
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*/ |
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if (ratio <= 5) |
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return 0; |
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if (ratio <= 25) |
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return min_percent(1, base, 1); |
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if (ratio <= 50) |
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return min_percent(1, base, 1); |
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if (ratio <= 75) |
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return min_percent(2, base, 2); |
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if (ratio <= 100) |
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return min_percent(3, base, 3); |
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if (ratio <= 250) |
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return min_percent(4, base, 4); |
|
|
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return min_percent(5, base, 8); |
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} |
|
|
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static void sfb_account_overflows(struct cpu_hw_sf *cpuhw, |
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struct hw_perf_event *hwc) |
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{ |
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unsigned long ratio, num; |
|
|
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if (!OVERFLOW_REG(hwc)) |
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return; |
|
|
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/* The sample_overflow contains the average number of sample data |
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* that has been lost because sample-data-blocks were full. |
|
* |
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* Calculate the total number of sample data entries that has been |
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* discarded. Then calculate the ratio of lost samples to total samples |
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* per second in percent. |
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*/ |
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ratio = DIV_ROUND_UP(100 * OVERFLOW_REG(hwc) * cpuhw->sfb.num_sdb, |
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sample_rate_to_freq(&cpuhw->qsi, SAMPL_RATE(hwc))); |
|
|
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/* Compute number of sample-data-blocks */ |
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num = compute_sfb_extent(ratio, cpuhw->sfb.num_sdb); |
|
if (num) |
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sfb_account_allocs(num, hwc); |
|
|
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debug_sprintf_event(sfdbg, 5, "%s: overflow %llu ratio %lu num %lu\n", |
|
__func__, OVERFLOW_REG(hwc), ratio, num); |
|
OVERFLOW_REG(hwc) = 0; |
|
} |
|
|
|
/* extend_sampling_buffer() - Extend sampling buffer |
|
* @sfb: Sampling buffer structure (for local CPU) |
|
* @hwc: Perf event hardware structure |
|
* |
|
* Use this function to extend the sampling buffer based on the overflow counter |
|
* and postponed allocation extents stored in the specified Perf event hardware. |
|
* |
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* Important: This function disables the sampling facility in order to safely |
|
* change the sampling buffer structure. Do not call this function |
|
* when the PMU is active. |
|
*/ |
|
static void extend_sampling_buffer(struct sf_buffer *sfb, |
|
struct hw_perf_event *hwc) |
|
{ |
|
unsigned long num, num_old; |
|
int rc; |
|
|
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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. |
|
*/ |
|
sf_disable(); |
|
|
|
/* Extend the sampling buffer. |
|
* This memory allocation typically happens in an atomic context when |
|
* 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, "%s: realloc failed with rc %i\n", |
|
__func__, rc); |
|
|
|
if (sfb_has_pending_allocs(sfb, hwc)) |
|
debug_sprintf_event(sfdbg, 5, "%s: " |
|
"req %lu alloc %lu remaining %lu\n", |
|
__func__, num, sfb->num_sdb - num_old, |
|
sfb_pending_allocs(sfb, hwc)); |
|
} |
|
|
|
/* Number of perf events counting hardware events */ |
|
static atomic_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); |
|
|
|
err = 0; |
|
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, |
|
"%s: initialized: cpuhw %p\n", __func__, |
|
cpusf); |
|
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, |
|
"%s: released: cpuhw %p\n", __func__, |
|
cpusf); |
|
break; |
|
} |
|
if (err) |
|
*((int *) flags) |= PMC_FAILURE; |
|
} |
|
|
|
static void release_pmc_hardware(void) |
|
{ |
|
int flags = PMC_RELEASE; |
|
|
|
irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT); |
|
on_each_cpu(setup_pmc_cpu, &flags, 1); |
|
} |
|
|
|
static int 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(); |
|
mutex_unlock(&pmc_reserve_mutex); |
|
} |
|
} |
|
|
|
static void hw_init_period(struct hw_perf_event *hwc, u64 period) |
|
{ |
|
hwc->sample_period = period; |
|
hwc->last_period = hwc->sample_period; |
|
local64_set(&hwc->period_left, hwc->sample_period); |
|
} |
|
|
|
static unsigned long hw_limit_rate(const struct hws_qsi_info_block *si, |
|
unsigned long rate) |
|
{ |
|
return clamp_t(unsigned long, rate, |
|
si->min_sampl_rate, si->max_sampl_rate); |
|
} |
|
|
|
static u32 cpumsf_pid_type(struct perf_event *event, |
|
u32 pid, enum pid_type type) |
|
{ |
|
struct task_struct *tsk; |
|
|
|
/* Idle process */ |
|
if (!pid) |
|
goto out; |
|
|
|
tsk = find_task_by_pid_ns(pid, &init_pid_ns); |
|
pid = -1; |
|
if (tsk) { |
|
/* |
|
* Only top level events contain the pid namespace in which |
|
* they are created. |
|
*/ |
|
if (event->parent) |
|
event = event->parent; |
|
pid = __task_pid_nr_ns(tsk, type, event->ns); |
|
/* |
|
* See also 1d953111b648 |
|
* "perf/core: Don't report zero PIDs for exiting tasks". |
|
*/ |
|
if (!pid && !pid_alive(tsk)) |
|
pid = -1; |
|
} |
|
out: |
|
return pid; |
|
} |
|
|
|
static void cpumsf_output_event_pid(struct perf_event *event, |
|
struct perf_sample_data *data, |
|
struct pt_regs *regs) |
|
{ |
|
u32 pid; |
|
struct perf_event_header header; |
|
struct perf_output_handle handle; |
|
|
|
/* |
|
* Obtain the PID from the basic-sampling data entry and |
|
* correct the data->tid_entry.pid value. |
|
*/ |
|
pid = data->tid_entry.pid; |
|
|
|
/* Protect callchain buffers, tasks */ |
|
rcu_read_lock(); |
|
|
|
perf_prepare_sample(&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) */ |
|
data->tid_entry.pid = cpumsf_pid_type(event, pid, PIDTYPE_TGID); |
|
data->tid_entry.tid = cpumsf_pid_type(event, pid, PIDTYPE_PID); |
|
|
|
perf_output_sample(&handle, &header, data, event); |
|
perf_output_end(&handle); |
|
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) { |
|
debug_sprintf_event(sfdbg, 1, "%s: " |
|
"Sampling rate exceeds maximum " |
|
"perf sample rate\n", __func__); |
|
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)); |
|
debug_sprintf_event(sfdbg, 4, "%s: cpu %d period %#llx freq %d,%#lx\n", |
|
__func__, event->cpu, event->attr.sample_period, |
|
event->attr.freq, SAMPLE_FREQ_MODE(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; |
|
int cpu, err; |
|
|
|
/* 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); |
|
} |
|
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, |
|
* when attaching to a task. If this is specified, use the query |
|
* sampling info from the current CPU, otherwise use event->cpu to |
|
* retrieve the per-CPU information. |
|
* Later, cpuhw indicates whether to allocate sampling buffers for a |
|
* particular CPU (cpuhw!=NULL) or each online CPU (cpuw==NULL). |
|
*/ |
|
memset(&si, 0, sizeof(si)); |
|
cpuhw = NULL; |
|
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. |
|
*/ |
|
cpuhw = &per_cpu(cpu_hw_sf, event->cpu); |
|
si = cpuhw->qsi; |
|
} |
|
|
|
/* Check sampling facility authorization and, if not authorized, |
|
* fall back to other PMUs. It is safe to check any CPU because |
|
* the authorization is identical for all configured CPUs. |
|
*/ |
|
if (!si.as) { |
|
err = -ENOENT; |
|
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; |
|
|
|
/* Check if diagnostic sampling is requested. Deny if the required |
|
* sampling authorization is missing. |
|
*/ |
|
if (attr->config == PERF_EVENT_CPUM_SF_DIAG) { |
|
if (!si.ad) { |
|
err = -EPERM; |
|
goto out; |
|
} |
|
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; |
|
|
|
err = __hw_perf_event_init_rate(event, &si); |
|
if (err) |
|
goto out; |
|
|
|
/* Initialize sample data overflow accounting */ |
|
hwc->extra_reg.reg = REG_OVERFLOW; |
|
OVERFLOW_REG(hwc) = 0; |
|
|
|
/* Use AUX buffer. No need to allocate it by ourself */ |
|
if (attr->config == PERF_EVENT_CPUM_SF_DIAG) |
|
return 0; |
|
|
|
/* Allocate the per-CPU sampling buffer using the CPU information |
|
* from the event. If the event is not pinned to a particular |
|
* CPU (event->cpu == -1; or cpuhw == NULL), allocate sampling |
|
* buffers for each online CPU. |
|
*/ |
|
if (cpuhw) |
|
/* Event is pinned to a particular CPU */ |
|
err = allocate_buffers(cpuhw, hwc); |
|
else { |
|
/* Event is not pinned, allocate sampling buffer on |
|
* each online CPU |
|
*/ |
|
for_each_online_cpu(cpu) { |
|
cpuhw = &per_cpu(cpu_hw_sf, cpu); |
|
err = allocate_buffers(cpuhw, hwc); |
|
if (err) |
|
break; |
|
} |
|
} |
|
|
|
/* If PID/TID sampling is active, replace the default overflow |
|
* handler to extract and resolve the PIDs from the basic-sampling |
|
* data entries. |
|
*/ |
|
if (event->attr.sample_type & PERF_SAMPLE_TID) |
|
if (is_default_overflow_handler(event)) |
|
event->overflow_handler = cpumsf_output_event_pid; |
|
out: |
|
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 */ |
|
/* No support for callchain, stacks and registers */ |
|
if (has_branch_stack(event) || is_callchain_event(event)) |
|
return -EOPNOTSUPP; |
|
|
|
switch (event->attr.type) { |
|
case PERF_TYPE_RAW: |
|
if ((event->attr.config != PERF_EVENT_CPUM_SF) && |
|
(event->attr.config != PERF_EVENT_CPUM_SF_DIAG)) |
|
return -ENOENT; |
|
break; |
|
case PERF_TYPE_HARDWARE: |
|
/* Support sampling of CPU cycles in addition to the |
|
* counter facility. However, the counter facility |
|
* is more precise and, hence, restrict this PMU to |
|
* sampling events only. |
|
*/ |
|
if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES) |
|
return -ENOENT; |
|
if (!is_sampling_event(event)) |
|
return -ENOENT; |
|
break; |
|
default: |
|
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. |
|
*/ |
|
if (event->attr.exclude_hv) |
|
event->attr.exclude_hv = 0; |
|
if (event->attr.exclude_idle) |
|
event->attr.exclude_idle = 0; |
|
|
|
err = __hw_perf_event_init(event); |
|
if (unlikely(err)) |
|
if (event->destroy) |
|
event->destroy(event); |
|
return err; |
|
} |
|
|
|
static void cpumsf_pmu_enable(struct pmu *pmu) |
|
{ |
|
struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf); |
|
struct hw_perf_event *hwc; |
|
int err; |
|
|
|
if (cpuhw->flags & PMU_F_ENABLED) |
|
return; |
|
|
|
if (cpuhw->flags & PMU_F_ERR_MASK) |
|
return; |
|
|
|
/* Check whether to extent the sampling buffer. |
|
* |
|
* Two conditions trigger an increase of the sampling buffer for a |
|
* perf event: |
|
* 1. Postponed buffer allocations from the event initialization. |
|
* 2. Sampling overflows that contribute to pending allocations. |
|
* |
|
* Note that the extend_sampling_buffer() function disables the sampling |
|
* 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); |
|
extend_sampling_buffer(&cpuhw->sfb, hwc); |
|
} |
|
/* Rate may be adjusted with ioctl() */ |
|
cpuhw->lsctl.interval = SAMPL_RATE(&cpuhw->event->hw); |
|
} |
|
|
|
/* (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); |
|
return; |
|
} |
|
|
|
/* Load current program parameter */ |
|
lpp(&S390_lowcore.lpp); |
|
|
|
debug_sprintf_event(sfdbg, 6, "%s: es %i cs %i ed %i cd %i " |
|
"interval %#lx tear %#lx dear %#lx\n", __func__, |
|
cpuhw->lsctl.es, cpuhw->lsctl.cs, cpuhw->lsctl.ed, |
|
cpuhw->lsctl.cd, cpuhw->lsctl.interval, |
|
cpuhw->lsctl.tear, cpuhw->lsctl.dear); |
|
} |
|
|
|
static void cpumsf_pmu_disable(struct pmu *pmu) |
|
{ |
|
struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf); |
|
struct hws_lsctl_request_block inactive; |
|
struct hws_qsi_info_block si; |
|
int err; |
|
|
|
if (!(cpuhw->flags & PMU_F_ENABLED)) |
|
return; |
|
|
|
if (cpuhw->flags & PMU_F_ERR_MASK) |
|
return; |
|
|
|
/* Switch off sampling activation control */ |
|
inactive = cpuhw->lsctl; |
|
inactive.cs = 0; |
|
inactive.cd = 0; |
|
|
|
err = lsctl(&inactive); |
|
if (err) { |
|
pr_err("Loading sampling controls failed: op %i err %i\n", |
|
2, err); |
|
return; |
|
} |
|
|
|
/* Save state of TEAR and DEAR register contents */ |
|
err = qsi(&si); |
|
if (!err) { |
|
/* 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, "%s: qsi() failed with err %i\n", |
|
__func__, err); |
|
|
|
cpuhw->flags &= ~PMU_F_ENABLED; |
|
} |
|
|
|
/* perf_exclude_event() - Filter event |
|
* @event: The perf event |
|
* @regs: pt_regs structure |
|
* @sde_regs: Sample-data-entry (sde) regs structure |
|
* |
|
* Filter perf events according to their exclude specification. |
|
* |
|
* Return non-zero if the event shall be excluded. |
|
*/ |
|
static int perf_exclude_event(struct perf_event *event, struct pt_regs *regs, |
|
struct perf_sf_sde_regs *sde_regs) |
|
{ |
|
if (event->attr.exclude_user && user_mode(regs)) |
|
return 1; |
|
if (event->attr.exclude_kernel && !user_mode(regs)) |
|
return 1; |
|
if (event->attr.exclude_guest && sde_regs->in_guest) |
|
return 1; |
|
if (event->attr.exclude_host && !sde_regs->in_guest) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
/* perf_push_sample() - Push samples to perf |
|
* @event: The perf event |
|
* @sample: Hardware sample data |
|
* |
|
* Use the hardware sample data to create perf event sample. The sample |
|
* is the pushed to the event subsystem and the function checks for |
|
* possible event overflows. If an event overflow occurs, the PMU is |
|
* stopped. |
|
* |
|
* Return non-zero if an event overflow occurred. |
|
*/ |
|
static int perf_push_sample(struct perf_event *event, |
|
struct hws_basic_entry *basic) |
|
{ |
|
int overflow; |
|
struct pt_regs regs; |
|
struct perf_sf_sde_regs *sde_regs; |
|
struct perf_sample_data data; |
|
|
|
/* Setup perf sample */ |
|
perf_sample_data_init(&data, 0, event->hw.last_period); |
|
|
|
/* Setup pt_regs to look like an CPU-measurement external interrupt |
|
* using the Program Request Alert code. The regs.int_parm_long |
|
* field which is unused contains additional sample-data-entry related |
|
* indicators. |
|
*/ |
|
memset(®s, 0, sizeof(regs)); |
|
regs.int_code = 0x1407; |
|
regs.int_parm = CPU_MF_INT_SF_PRA; |
|
sde_regs = (struct perf_sf_sde_regs *) ®s.int_parm_long; |
|
|
|
psw_bits(regs.psw).ia = basic->ia; |
|
psw_bits(regs.psw).dat = basic->T; |
|
psw_bits(regs.psw).wait = basic->W; |
|
psw_bits(regs.psw).pstate = basic->P; |
|
psw_bits(regs.psw).as = basic->AS; |
|
|
|
/* |
|
* Use the hardware provided configuration level to decide if the |
|
* sample belongs to a guest or host. If that is not available, |
|
* fall back to the following heuristics: |
|
* A non-zero guest program parameter always indicates a guest |
|
* sample. Some early samples or samples from guests without |
|
* lpp usage would be misaccounted to the host. We use the asn |
|
* value as an addon heuristic to detect most of these guest samples. |
|
* If the value differs from 0xffff (the host value), we assume to |
|
* be a KVM guest. |
|
*/ |
|
switch (basic->CL) { |
|
case 1: /* logical partition */ |
|
sde_regs->in_guest = 0; |
|
break; |
|
case 2: /* virtual machine */ |
|
sde_regs->in_guest = 1; |
|
break; |
|
default: /* old machine, use heuristics */ |
|
if (basic->gpp || basic->prim_asn != 0xffff) |
|
sde_regs->in_guest = 1; |
|
break; |
|
} |
|
|
|
/* |
|
* Store the PID value from the sample-data-entry to be |
|
* processed and resolved by cpumsf_output_event_pid(). |
|
*/ |
|
data.tid_entry.pid = basic->hpp & LPP_PID_MASK; |
|
|
|
overflow = 0; |
|
if (perf_exclude_event(event, ®s, sde_regs)) |
|
goto out; |
|
if (perf_event_overflow(event, &data, ®s)) { |
|
overflow = 1; |
|
event->pmu->stop(event, 0); |
|
} |
|
perf_event_update_userpage(event); |
|
out: |
|
return overflow; |
|
} |
|
|
|
static void perf_event_count_update(struct perf_event *event, u64 count) |
|
{ |
|
local64_add(count, &event->count); |
|
} |
|
|
|
/* hw_collect_samples() - Walk through a sample-data-block and collect samples |
|
* @event: The perf event |
|
* @sdbt: Sample-data-block table |
|
* @overflow: Event overflow counter |
|
* |
|
* Walks through a sample-data-block and collects sampling data entries that are |
|
* then pushed to the perf event subsystem. Depending on the sampling function, |
|
* there can be either basic-sampling or combined-sampling data entries. A |
|
* 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. |
|
* |
|
* 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 |
|
* ignored. |
|
* |
|
* The overflow variables counts the number of samples that has been discarded |
|
* due to a perf event overflow. |
|
*/ |
|
static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt, |
|
unsigned long long *overflow) |
|
{ |
|
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) { |
|
/* Check for an empty sample */ |
|
if (!sample->def) |
|
break; |
|
|
|
/* Update perf event period */ |
|
perf_event_count_update(event, SAMPL_RATE(&event->hw)); |
|
|
|
/* Check whether sample is valid */ |
|
if (sample->def == 0x0001) { |
|
/* If an event overflow occurred, the PMU is stopped to |
|
* throttle event delivery. Remaining sample data is |
|
* discarded. |
|
*/ |
|
if (!*overflow) { |
|
/* Check whether sample is consistent */ |
|
if (sample->I == 0 && sample->W == 0) { |
|
/* Deliver sample data to perf */ |
|
*overflow = perf_push_sample(event, |
|
sample); |
|
} |
|
} else |
|
/* Count discarded samples */ |
|
*overflow += 1; |
|
} else { |
|
debug_sprintf_event(sfdbg, 4, |
|
"%s: Found unknown" |
|
" sampling data entry: te->f %i" |
|
" basic.def %#4x (%p)\n", __func__, |
|
te->f, sample->def, sample); |
|
/* Sample slot is not yet written or other record. |
|
* |
|
* This condition can occur if the buffer was reused |
|
* from a combined basic- and diagnostic-sampling. |
|
* If only basic-sampling is then active, entries are |
|
* written into the larger diagnostic entries. |
|
* This is typically the case for sample-data-blocks |
|
* that are not full. Stop processing if the first |
|
* invalid format was detected. |
|
*/ |
|
if (!te->f) |
|
break; |
|
} |
|
|
|
/* Reset sample slot and advance to next sample */ |
|
sample->def = 0; |
|
sample++; |
|
} |
|
} |
|
|
|
/* hw_perf_event_update() - Process sampling buffer |
|
* @event: The perf event |
|
* @flush_all: Flag to also flush partially filled sample-data-blocks |
|
* |
|
* Processes the sampling buffer and create perf event samples. |
|
* 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). |
|
*/ |
|
static void hw_perf_event_update(struct perf_event *event, int flush_all) |
|
{ |
|
struct hw_perf_event *hwc = &event->hw; |
|
struct hws_trailer_entry *te; |
|
unsigned long *sdbt; |
|
unsigned long long event_overflow, sampl_overflow, num_sdb, te_flags; |
|
int done; |
|
|
|
/* |
|
* AUX buffer is used when in diagnostic sampling mode. |
|
* No perf events/samples are created. |
|
*/ |
|
if (SAMPL_DIAG_MODE(&event->hw)) |
|
return; |
|
|
|
if (flush_all && SDB_FULL_BLOCKS(hwc)) |
|
flush_all = 0; |
|
|
|
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); |
|
|
|
/* Leave loop if no more work to do (block full indicator) */ |
|
if (!te->f) { |
|
done = 1; |
|
if (!flush_all) |
|
break; |
|
} |
|
|
|
/* Check the sample overflow count */ |
|
if (te->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, "%s: sdbt %#lx " |
|
"overflow %llu timestamp %#llx\n", |
|
__func__, (unsigned long)sdbt, te->overflow, |
|
(te->f) ? trailer_timestamp(te) : 0ULL); |
|
|
|
/* 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); |
|
num_sdb++; |
|
|
|
/* Reset trailer (using compare-double-and-swap) */ |
|
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)); |
|
|
|
/* Advance to next sample-data-block */ |
|
sdbt++; |
|
if (is_link_entry(sdbt)) |
|
sdbt = get_next_sdbt(sdbt); |
|
|
|
/* Update event hardware registers */ |
|
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; |
|
} |
|
|
|
/* 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); |
|
|
|
/* 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); |
|
debug_sprintf_event(sfdbg, 1, "%s: rate adjustment %ld\n", |
|
__func__, |
|
DIV_ROUND_UP(SAMPL_RATE(hwc), 10)); |
|
} |
|
|
|
if (sampl_overflow || event_overflow) |
|
debug_sprintf_event(sfdbg, 4, "%s: " |
|
"overflows: sample %llu event %llu" |
|
" total %llu num_sdb %llu\n", |
|
__func__, sampl_overflow, event_overflow, |
|
OVERFLOW_REG(hwc), 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) |
|
|
|
/* |
|
* Get trailer entry by index of SDB. |
|
*/ |
|
static struct hws_trailer_entry *aux_sdb_trailer(struct aux_buffer *aux, |
|
unsigned long index) |
|
{ |
|
unsigned long sdb; |
|
|
|
index = AUX_SDB_INDEX(aux, index); |
|
sdb = aux->sdb_index[index]; |
|
return (struct hws_trailer_entry *)trailer_entry_ptr(sdb); |
|
} |
|
|
|
/* |
|
* Finish sampling on the cpu. Called by cpumsf_pmu_del() with pmu |
|
* disabled. Collect the full SDBs in AUX buffer which have not reached |
|
* the point of alert indicator. And ignore the SDBs which are not |
|
* full. |
|
* |
|
* 1. Scan SDBs to see how much data is there and consume them. |
|
* 2. Remove alert indicator in the buffer. |
|
*/ |
|
static void aux_output_end(struct perf_output_handle *handle) |
|
{ |
|
unsigned long i, range_scan, idx; |
|
struct aux_buffer *aux; |
|
struct hws_trailer_entry *te; |
|
|
|
aux = perf_get_aux(handle); |
|
if (!aux) |
|
return; |
|
|
|
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)) |
|
break; |
|
} |
|
/* i is num of SDBs which are full */ |
|
perf_aux_output_end(handle, i << PAGE_SHIFT); |
|
|
|
/* 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, "%s: SDBs %ld range %ld head %ld\n", |
|
__func__, i, range_scan, aux->head); |
|
} |
|
|
|
/* |
|
* Start sampling on the CPU. Called by cpumsf_pmu_add() when an event |
|
* is first added to the CPU or rescheduled again to the CPU. It is called |
|
* with pmu disabled. |
|
* |
|
* 1. Reset the trailer of SDBs to get ready for new data. |
|
* 2. Tell the hardware where to put the data by reset the SDBs buffer |
|
* head(tear/dear). |
|
*/ |
|
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; |
|
struct hws_trailer_entry *te; |
|
|
|
if (WARN_ON_ONCE(handle->head & ~PAGE_MASK)) |
|
return -EINVAL; |
|
|
|
aux->head = handle->head >> PAGE_SHIFT; |
|
range = (handle->size + 1) >> PAGE_SHIFT; |
|
if (range <= 1) |
|
return -ENOMEM; |
|
|
|
/* |
|
* SDBs between aux->head and aux->empty_mark are already ready |
|
* for new data. range_scan is num of SDBs not within them. |
|
*/ |
|
debug_sprintf_event(sfdbg, 6, |
|
"%s: range %ld head %ld alert %ld empty %ld\n", |
|
__func__, range, aux->head, aux->alert_mark, |
|
aux->empty_mark); |
|
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 &= ~(SDB_TE_BUFFER_FULL_MASK | |
|
SDB_TE_ALERT_REQ_MASK); |
|
te->overflow = 0; |
|
} |
|
/* Save the position of empty SDBs */ |
|
aux->empty_mark = aux->head + range - 1; |
|
} |
|
|
|
/* 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; |
|
|
|
/* Reset hardware buffer 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, "%s: head %ld alert %ld empty %ld " |
|
"index %ld tear %#lx dear %#lx\n", __func__, |
|
aux->head, aux->alert_mark, aux->empty_mark, |
|
head / CPUM_SF_SDB_PER_TABLE, |
|
cpuhw->lsctl.tear, cpuhw->lsctl.dear); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Set alert indicator on SDB at index @alert_index while sampler is running. |
|
* |
|
* Return true if successfully. |
|
* Return false if full indicator is already set by hardware sampler. |
|
*/ |
|
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; |
|
struct hws_trailer_entry *te; |
|
|
|
te = aux_sdb_trailer(aux, alert_index); |
|
do { |
|
orig_flags = te->flags; |
|
*overflow = orig_overflow = te->overflow; |
|
if (orig_flags & SDB_TE_BUFFER_FULL_MASK) { |
|
/* |
|
* SDB is already set by hardware. |
|
* Abort and try to set somewhere |
|
* behind. |
|
*/ |
|
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)); |
|
return true; |
|
} |
|
|
|
/* |
|
* aux_reset_buffer() - Scan and setup SDBs for new samples |
|
* @aux: The AUX buffer to set |
|
* @range: The range of SDBs to scan started from aux->head |
|
* @overflow: Set to overflow count |
|
* |
|
* Set alert indicator on the SDB at index of aux->alert_mark. If this SDB is |
|
* marked as empty, check if it is already set full by the hardware sampler. |
|
* If yes, that means new data is already there before we can set an alert |
|
* indicator. Caller should try to set alert indicator to some position behind. |
|
* |
|
* Scan the SDBs in AUX buffer from behind aux->empty_mark. They are used |
|
* previously and have already been consumed by user space. Reset these SDBs |
|
* (clear full indicator and alert indicator) for new data. |
|
* If aux->alert_mark fall in this area, just set it. Overflow count is |
|
* recorded while scanning. |
|
* |
|
* SDBs between aux->head and aux->empty_mark are already reset at last time. |
|
* and ready for new samples. So scanning on this area could be skipped. |
|
* |
|
* Return true if alert indicator is set successfully and false if not. |
|
*/ |
|
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; |
|
unsigned long i, range_scan, idx, idx_old; |
|
struct hws_trailer_entry *te; |
|
|
|
debug_sprintf_event(sfdbg, 6, "%s: range %ld head %ld alert %ld " |
|
"empty %ld\n", __func__, range, aux->head, |
|
aux->alert_mark, aux->empty_mark); |
|
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 |
|
* sampler. |
|
*/ |
|
return aux_set_alert(aux, aux->alert_mark, overflow); |
|
|
|
if (aux->alert_mark <= aux->empty_mark) |
|
/* |
|
* Set alert indicator on empty SDB. Should check race |
|
* with hardware sampler. |
|
*/ |
|
if (!aux_set_alert(aux, aux->alert_mark, overflow)) |
|
return false; |
|
|
|
/* |
|
* Scan the SDBs to clear full and alert indicator used previously. |
|
* 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); |
|
idx_old = idx = aux->empty_mark + 1; |
|
for (i = 0; i < range_scan; i++, idx++) { |
|
te = aux_sdb_trailer(aux, idx); |
|
do { |
|
orig_flags = te->flags; |
|
orig_overflow = te->overflow; |
|
new_flags = orig_flags & ~SDB_TE_BUFFER_FULL_MASK; |
|
if (idx == aux->alert_mark) |
|
new_flags |= SDB_TE_ALERT_REQ_MASK; |
|
else |
|
new_flags &= ~SDB_TE_ALERT_REQ_MASK; |
|
} while (!cmpxchg_double(&te->flags, &te->overflow, |
|
orig_flags, orig_overflow, |
|
new_flags, 0ULL)); |
|
*overflow += orig_overflow; |
|
} |
|
|
|
/* Update empty_mark to new position */ |
|
aux->empty_mark = aux->head + range - 1; |
|
|
|
debug_sprintf_event(sfdbg, 6, "%s: range_scan %ld idx %ld..%ld " |
|
"empty %ld\n", __func__, range_scan, idx_old, |
|
idx - 1, aux->empty_mark); |
|
return true; |
|
} |
|
|
|
/* |
|
* Measurement alert handler for diagnostic mode sampling. |
|
*/ |
|
static void hw_collect_aux(struct cpu_hw_sf *cpuhw) |
|
{ |
|
struct aux_buffer *aux; |
|
int done = 0; |
|
unsigned long range = 0, size; |
|
unsigned long long overflow = 0; |
|
struct perf_output_handle *handle = &cpuhw->handle; |
|
unsigned long num_sdb; |
|
|
|
aux = perf_get_aux(handle); |
|
if (WARN_ON_ONCE(!aux)) |
|
return; |
|
|
|
/* Inform user space new data arrived */ |
|
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; |
|
while (!done) { |
|
/* Get an output handle */ |
|
aux = perf_aux_output_begin(handle, cpuhw->event); |
|
if (handle->size == 0) { |
|
pr_err("The AUX buffer with %lu pages for the " |
|
"diagnostic-sampling mode is full\n", |
|
num_sdb); |
|
debug_sprintf_event(sfdbg, 1, |
|
"%s: AUX buffer used up\n", |
|
__func__); |
|
break; |
|
} |
|
if (WARN_ON_ONCE(!aux)) |
|
return; |
|
|
|
/* Update head and alert_mark to new position */ |
|
aux->head = handle->head >> PAGE_SHIFT; |
|
range = (handle->size + 1) >> PAGE_SHIFT; |
|
if (range == 1) |
|
aux->alert_mark = aux->head; |
|
else |
|
aux->alert_mark = aux->head + range/2 - 1; |
|
|
|
if (aux_reset_buffer(aux, range, &overflow)) { |
|
if (!overflow) { |
|
done = 1; |
|
break; |
|
} |
|
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", aux->sfb.num_sdb); |
|
debug_sprintf_event(sfdbg, 1, "%s: head %ld range %ld " |
|
"overflow %lld\n", __func__, |
|
aux->head, range, overflow); |
|
} else { |
|
size = AUX_SDB_NUM_ALERT(aux) << PAGE_SHIFT; |
|
perf_aux_output_end(&cpuhw->handle, size); |
|
debug_sprintf_event(sfdbg, 6, "%s: head %ld alert %ld " |
|
"already full, try another\n", |
|
__func__, |
|
aux->head, aux->alert_mark); |
|
} |
|
} |
|
|
|
if (done) |
|
debug_sprintf_event(sfdbg, 6, "%s: head %ld alert %ld " |
|
"empty %ld\n", __func__, aux->head, |
|
aux->alert_mark, aux->empty_mark); |
|
} |
|
|
|
/* |
|
* Callback when freeing AUX buffers. |
|
*/ |
|
static void aux_buffer_free(void *data) |
|
{ |
|
struct aux_buffer *aux = data; |
|
unsigned long i, num_sdbt; |
|
|
|
if (!aux) |
|
return; |
|
|
|
/* Free SDBT. SDB is freed by the caller */ |
|
num_sdbt = aux->sfb.num_sdbt; |
|
for (i = 0; i < num_sdbt; i++) |
|
free_page(aux->sdbt_index[i]); |
|
|
|
kfree(aux->sdbt_index); |
|
kfree(aux->sdb_index); |
|
kfree(aux); |
|
|
|
debug_sprintf_event(sfdbg, 4, "%s: SDBTs %lu\n", __func__, num_sdbt); |
|
} |
|
|
|
static void aux_sdb_init(unsigned long sdb) |
|
{ |
|
struct hws_trailer_entry *te; |
|
|
|
te = (struct hws_trailer_entry *)trailer_entry_ptr(sdb); |
|
|
|
/* Save clock base */ |
|
te->clock_base = 1; |
|
te->progusage2 = tod_clock_base.tod; |
|
} |
|
|
|
/* |
|
* aux_buffer_setup() - Setup AUX buffer for diagnostic mode sampling |
|
* @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 |
|
* |
|
* This is the callback when setup an event using AUX buffer. Perf tool can |
|
* trigger this by an additional mmap() call on the event. Unlike the buffer |
|
* for basic samples, AUX buffer belongs to the event. It is scheduled with |
|
* the task among online cpus when it is a per-thread event. |
|
* |
|
* Return the private AUX buffer structure if success or NULL if fails. |
|
*/ |
|
static void *aux_buffer_setup(struct perf_event *event, void **pages, |
|
int nr_pages, bool snapshot) |
|
{ |
|
struct sf_buffer *sfb; |
|
struct aux_buffer *aux; |
|
unsigned long *new, *tail; |
|
int i, n_sdbt; |
|
|
|
if (!nr_pages || !pages) |
|
return NULL; |
|
|
|
if (nr_pages > CPUM_SF_MAX_SDB * CPUM_SF_SDB_DIAG_FACTOR) { |
|
pr_err("AUX buffer size (%i pages) is larger than the " |
|
"maximum sampling buffer limit\n", |
|
nr_pages); |
|
return NULL; |
|
} else if (nr_pages < CPUM_SF_MIN_SDB * CPUM_SF_SDB_DIAG_FACTOR) { |
|
pr_err("AUX buffer size (%i pages) is less than the " |
|
"minimum sampling buffer limit\n", |
|
nr_pages); |
|
return NULL; |
|
} |
|
|
|
/* Allocate aux_buffer struct for the event */ |
|
aux = kzalloc(sizeof(struct aux_buffer), GFP_KERNEL); |
|
if (!aux) |
|
goto no_aux; |
|
sfb = &aux->sfb; |
|
|
|
/* Allocate sdbt_index for fast reference */ |
|
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; |
|
|
|
/* Allocate sdb_index for fast reference */ |
|
aux->sdb_index = kmalloc_array(nr_pages, sizeof(void *), GFP_KERNEL); |
|
if (!aux->sdb_index) |
|
goto no_sdb_index; |
|
|
|
/* Allocate the first SDBT */ |
|
sfb->num_sdbt = 0; |
|
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; |
|
tail = sfb->tail = sfb->sdbt; |
|
|
|
/* |
|
* Link the provided pages of AUX buffer to SDBT. |
|
* Allocate SDBT if needed. |
|
*/ |
|
for (i = 0; i < nr_pages; i++, tail++) { |
|
if (require_table_link(tail)) { |
|
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 = new; |
|
} |
|
/* Tail is the entry in a SDBT */ |
|
*tail = (unsigned long)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; |
|
sfb->tail = tail; |
|
|
|
/* |
|
* Initial all SDBs are zeroed. Mark it as empty. |
|
* So there is no need to clear the full indicator |
|
* when this event is first added. |
|
*/ |
|
aux->empty_mark = sfb->num_sdb - 1; |
|
|
|
debug_sprintf_event(sfdbg, 4, "%s: SDBTs %lu SDBs %lu\n", __func__, |
|
sfb->num_sdbt, sfb->num_sdb); |
|
|
|
return aux; |
|
|
|
no_sdbt: |
|
/* SDBs (AUX buffer pages) are freed by caller */ |
|
for (i = 0; i < sfb->num_sdbt; i++) |
|
free_page(aux->sdbt_index[i]); |
|
kfree(aux->sdb_index); |
|
no_sdb_index: |
|
kfree(aux->sdbt_index); |
|
no_sdbt_index: |
|
kfree(aux); |
|
no_aux: |
|
return NULL; |
|
} |
|
|
|
static void cpumsf_pmu_read(struct perf_event *event) |
|
{ |
|
/* Nothing to do ... updates are interrupt-driven */ |
|
} |
|
|
|
/* Check if the new sampling period/freqeuncy 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) { |
|
if (qsi(&si)) |
|
return -ENODEV; |
|
} 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 = !!SAMPLE_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)); |
|
debug_sprintf_event(sfdbg, 4, "%s:" |
|
" cpu %d value %#llx period %#llx freq %d\n", |
|
__func__, event->cpu, value, |
|
event->attr.sample_period, do_freq); |
|
return 0; |
|
} |
|
|
|
/* Activate sampling control. |
|
* Next call of pmu_enable() starts sampling. |
|
*/ |
|
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))) |
|
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; |
|
if (SAMPL_DIAG_MODE(&event->hw)) |
|
cpuhw->lsctl.cd = 1; |
|
perf_pmu_enable(event->pmu); |
|
} |
|
|
|
/* Deactivate sampling control. |
|
* Next call of pmu_enable() stops sampling. |
|
*/ |
|
static void cpumsf_pmu_stop(struct perf_event *event, int flags) |
|
{ |
|
struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf); |
|
|
|
if (event->hw.state & PERF_HES_STOPPED) |
|
return; |
|
|
|
perf_pmu_disable(event->pmu); |
|
cpuhw->lsctl.cs = 0; |
|
cpuhw->lsctl.cd = 0; |
|
event->hw.state |= PERF_HES_STOPPED; |
|
|
|
if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) { |
|
hw_perf_event_update(event, 1); |
|
event->hw.state |= PERF_HES_UPTODATE; |
|
} |
|
perf_pmu_enable(event->pmu); |
|
} |
|
|
|
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; |
|
|
|
if (cpuhw->flags & PMU_F_IN_USE) |
|
return -EAGAIN; |
|
|
|
if (!SAMPL_DIAG_MODE(&event->hw) && !cpuhw->sfb.sdbt) |
|
return -EINVAL; |
|
|
|
err = 0; |
|
perf_pmu_disable(event->pmu); |
|
|
|
event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED; |
|
|
|
/* Set up sampling controls. Always program the sampling register |
|
* using the SDB-table start. Reset TEAR_REG event hardware register |
|
* that is used by hw_perf_event_update() to store the sampling buffer |
|
* position after samples have been flushed. |
|
*/ |
|
cpuhw->lsctl.s = 0; |
|
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; |
|
TEAR_REG(&event->hw) = (unsigned long) cpuhw->sfb.sdbt; |
|
} |
|
|
|
/* Ensure sampling functions are in the disabled state. If disabled, |
|
* switch on sampling enable control. */ |
|
if (WARN_ON_ONCE(cpuhw->lsctl.es == 1 || cpuhw->lsctl.ed == 1)) { |
|
err = -EAGAIN; |
|
goto out; |
|
} |
|
if (SAMPL_DIAG_MODE(&event->hw)) { |
|
aux = perf_aux_output_begin(&cpuhw->handle, event); |
|
if (!aux) { |
|
err = -EINVAL; |
|
goto out; |
|
} |
|
err = aux_output_begin(&cpuhw->handle, aux, cpuhw); |
|
if (err) |
|
goto out; |
|
cpuhw->lsctl.ed = 1; |
|
} |
|
cpuhw->lsctl.es = 1; |
|
|
|
/* Set in_use flag and store event */ |
|
cpuhw->event = event; |
|
cpuhw->flags |= PMU_F_IN_USE; |
|
|
|
if (flags & PERF_EF_START) |
|
cpumsf_pmu_start(event, PERF_EF_RELOAD); |
|
out: |
|
perf_event_update_userpage(event); |
|
perf_pmu_enable(event->pmu); |
|
return err; |
|
} |
|
|
|
static void cpumsf_pmu_del(struct perf_event *event, int flags) |
|
{ |
|
struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf); |
|
|
|
perf_pmu_disable(event->pmu); |
|
cpumsf_pmu_stop(event, PERF_EF_UPDATE); |
|
|
|
cpuhw->lsctl.es = 0; |
|
cpuhw->lsctl.ed = 0; |
|
cpuhw->flags &= ~PMU_F_IN_USE; |
|
cpuhw->event = NULL; |
|
|
|
if (SAMPL_DIAG_MODE(&event->hw)) |
|
aux_output_end(&cpuhw->handle); |
|
perf_event_update_userpage(event); |
|
perf_pmu_enable(event->pmu); |
|
} |
|
|
|
CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC, PERF_EVENT_CPUM_SF); |
|
CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC_DIAG, PERF_EVENT_CPUM_SF_DIAG); |
|
|
|
/* Attribute list for CPU_SF. |
|
* |
|
* The availablitiy depends on the CPU_MF sampling facility authorization |
|
* for basic + diagnositic samples. This is determined at initialization |
|
* time by the sampling facility device driver. |
|
* If the authorization for basic samples is turned off, it should be |
|
* also turned off for diagnostic sampling. |
|
* |
|
* During initialization of the device driver, check the authorization |
|
* level for diagnostic sampling and installs the attribute |
|
* file for diagnostic sampling if necessary. |
|
* |
|
* For now install a placeholder to reference all possible attributes: |
|
* SF_CYCLES_BASIC and SF_CYCLES_BASIC_DIAG. |
|
* Add another entry for the final NULL pointer. |
|
*/ |
|
enum { |
|
SF_CYCLES_BASIC_ATTR_IDX = 0, |
|
SF_CYCLES_BASIC_DIAG_ATTR_IDX, |
|
SF_CYCLES_ATTR_MAX |
|
}; |
|
|
|
static struct attribute *cpumsf_pmu_events_attr[SF_CYCLES_ATTR_MAX + 1] = { |
|
[SF_CYCLES_BASIC_ATTR_IDX] = CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC) |
|
}; |
|
|
|
PMU_FORMAT_ATTR(event, "config:0-63"); |
|
|
|
static struct attribute *cpumsf_pmu_format_attr[] = { |
|
&format_attr_event.attr, |
|
NULL, |
|
}; |
|
|
|
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, |
|
NULL, |
|
}; |
|
|
|
static struct pmu cpumf_sampling = { |
|
.pmu_enable = cpumsf_pmu_enable, |
|
.pmu_disable = cpumsf_pmu_disable, |
|
|
|
.event_init = cpumsf_pmu_event_init, |
|
.add = cpumsf_pmu_add, |
|
.del = cpumsf_pmu_del, |
|
|
|
.start = cpumsf_pmu_start, |
|
.stop = cpumsf_pmu_stop, |
|
.read = cpumsf_pmu_read, |
|
|
|
.attr_groups = cpumsf_pmu_attr_groups, |
|
|
|
.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, |
|
unsigned int alert, unsigned long unused) |
|
{ |
|
struct cpu_hw_sf *cpuhw; |
|
|
|
if (!(alert & CPU_MF_INT_SF_MASK)) |
|
return; |
|
inc_irq_stat(IRQEXT_CMS); |
|
cpuhw = this_cpu_ptr(&cpu_hw_sf); |
|
|
|
/* Measurement alerts are shared and might happen when the PMU |
|
* is not reserved. Ignore these alerts in this case. */ |
|
if (!(cpuhw->flags & PMU_F_RESERVED)) |
|
return; |
|
|
|
/* The processing below must take care of multiple alert events that |
|
* might be indicated concurrently. */ |
|
|
|
/* Program alert request */ |
|
if (alert & CPU_MF_INT_SF_PRA) { |
|
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, "%s: alert %#x\n", __func__, |
|
alert); |
|
|
|
/* Sampling authorization change request */ |
|
if (alert & CPU_MF_INT_SF_SACA) |
|
qsi(&cpuhw->qsi); |
|
|
|
/* Loss of sample data due to high-priority machine activities */ |
|
if (alert & CPU_MF_INT_SF_LSDA) { |
|
pr_err("Sample data was lost\n"); |
|
cpuhw->flags |= PMU_F_ERR_LSDA; |
|
sf_disable(); |
|
} |
|
|
|
/* 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", |
|
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)) |
|
return 0; |
|
|
|
local_irq_disable(); |
|
setup_pmc_cpu(&flags); |
|
local_irq_enable(); |
|
return 0; |
|
} |
|
|
|
static int s390_pmu_sf_online_cpu(unsigned int cpu) |
|
{ |
|
return cpusf_pmu_setup(cpu, PMC_INIT); |
|
} |
|
|
|
static int s390_pmu_sf_offline_cpu(unsigned int cpu) |
|
{ |
|
return cpusf_pmu_setup(cpu, PMC_RELEASE); |
|
} |
|
|
|
static int param_get_sfb_size(char *buffer, const struct kernel_param *kp) |
|
{ |
|
if (!cpum_sf_avail()) |
|
return -ENODEV; |
|
return sprintf(buffer, "%lu,%lu", CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB); |
|
} |
|
|
|
static int param_set_sfb_size(const char *val, const struct kernel_param *kp) |
|
{ |
|
int rc; |
|
unsigned long min, max; |
|
|
|
if (!cpum_sf_avail()) |
|
return -ENODEV; |
|
if (!val || !strlen(val)) |
|
return -EINVAL; |
|
|
|
/* Valid parameter values: "min,max" or "max" */ |
|
min = CPUM_SF_MIN_SDB; |
|
max = CPUM_SF_MAX_SDB; |
|
if (strchr(val, ',')) |
|
rc = (sscanf(val, "%lu,%lu", &min, &max) == 2) ? 0 : -EINVAL; |
|
else |
|
rc = kstrtoul(val, 10, &max); |
|
|
|
if (min < 2 || min >= max || max > get_num_physpages()) |
|
rc = -EINVAL; |
|
if (rc) |
|
return rc; |
|
|
|
sfb_set_limits(min, max); |
|
pr_info("The sampling buffer limits have changed to: " |
|
"min %lu max %lu (diag %lu)\n", |
|
CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB, CPUM_SF_SDB_DIAG_FACTOR); |
|
return 0; |
|
} |
|
|
|
#define param_check_sfb_size(name, p) __param_check(name, p, void) |
|
static const struct kernel_param_ops param_ops_sfb_size = { |
|
.set = param_set_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 |
|
static void __init pr_cpumsf_err(unsigned int reason) |
|
{ |
|
pr_err("Sampling facility support for perf is not available: " |
|
"reason %#x\n", reason); |
|
} |
|
|
|
static int __init init_cpum_sampling_pmu(void) |
|
{ |
|
struct hws_qsi_info_block si; |
|
int err; |
|
|
|
if (!cpum_sf_avail()) |
|
return -ENODEV; |
|
|
|
memset(&si, 0, sizeof(si)); |
|
if (qsi(&si)) { |
|
pr_cpumsf_err(RS_INIT_FAILURE_QSI); |
|
return -ENODEV; |
|
} |
|
|
|
if (!si.as && !si.ad) |
|
return -ENODEV; |
|
|
|
if (si.bsdes != sizeof(struct hws_basic_entry)) { |
|
pr_cpumsf_err(RS_INIT_FAILURE_BSDES); |
|
return -EINVAL; |
|
} |
|
|
|
if (si.ad) { |
|
sfb_set_limits(CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB); |
|
/* Sampling of diagnostic data authorized, |
|
* install event into attribute list of PMU device. |
|
*/ |
|
cpumsf_pmu_events_attr[SF_CYCLES_BASIC_DIAG_ATTR_IDX] = |
|
CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC_DIAG); |
|
} |
|
|
|
sfdbg = debug_register(KMSG_COMPONENT, 2, 1, 80); |
|
if (!sfdbg) { |
|
pr_err("Registering for s390dbf failed\n"); |
|
return -ENOMEM; |
|
} |
|
debug_register_view(sfdbg, &debug_sprintf_view); |
|
|
|
err = register_external_irq(EXT_IRQ_MEASURE_ALERT, |
|
cpumf_measurement_alert); |
|
if (err) { |
|
pr_cpumsf_err(RS_INIT_FAILURE_ALRT); |
|
debug_unregister(sfdbg); |
|
goto out; |
|
} |
|
|
|
err = perf_pmu_register(&cpumf_sampling, "cpum_sf", PERF_TYPE_RAW); |
|
if (err) { |
|
pr_cpumsf_err(RS_INIT_FAILURE_PERF); |
|
unregister_external_irq(EXT_IRQ_MEASURE_ALERT, |
|
cpumf_measurement_alert); |
|
debug_unregister(sfdbg); |
|
goto out; |
|
} |
|
|
|
cpuhp_setup_state(CPUHP_AP_PERF_S390_SF_ONLINE, "perf/s390/sf:online", |
|
s390_pmu_sf_online_cpu, s390_pmu_sf_offline_cpu); |
|
out: |
|
return err; |
|
} |
|
|
|
arch_initcall(init_cpum_sampling_pmu); |
|
core_param(cpum_sfb_size, CPUM_SF_MAX_SDB, sfb_size, 0644);
|
|
|