2101 строка
59 KiB
C
2101 строка
59 KiB
C
// 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 <brueckner@linux.vnet.ibm.com>
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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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#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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/* 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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/* 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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/* 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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/* 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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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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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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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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/* Debug feature */
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static debug_info_t *sfdbg;
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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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memset(&sreq, 0, sizeof(sreq));
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return lsctl(&sreq);
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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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* 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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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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/* 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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/* 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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/* 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,
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"free_sampling_buffer: freed sdbt=%p\n", sfb->sdbt);
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memset(sfb, 0, sizeof(*sfb));
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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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/* 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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/* Link SDB into the sample-data-block-table */
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*sdbt = sdb;
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return 0;
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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;
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if (!sfb->sdbt || !sfb->tail)
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return -EINVAL;
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if (!is_link_entry(sfb->tail))
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return -EINVAL;
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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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/* 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, "realloc_sampling_buffer: "
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"sampling buffer is not linked: origin=%p"
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"tail=%p\n",
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(void *) sfb->sdbt, (void *) tail);
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return -EINVAL;
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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 = new;
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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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break;
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sfb->num_sdb++;
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tail++;
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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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debug_sprintf_event(sfdbg, 4, "realloc_sampling_buffer: new buffer"
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" settings: sdbt=%lu sdb=%lu\n",
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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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* 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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if (sfb->sdbt)
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return -EINVAL;
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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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/* 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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/* 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, "alloc_sampling_buffer: "
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"realloc_sampling_buffer failed with rc=%i\n", rc);
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} else
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debug_sprintf_event(sfdbg, 4,
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"alloc_sampling_buffer: tear=%p dear=%p\n",
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sfb->sdbt, (void *) *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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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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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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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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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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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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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, factor;
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size_t sample_size;
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/* Calculate sampling buffers using 4K pages
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*
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* 1. Determine the sample data size which depends on the used
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* sampling functions, for example, basic-sampling or
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* basic-sampling with diagnostic-sampling.
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*
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* 2. Use the sampling frequency as input. The sampling buffer is
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* designed for almost one second. This can be adjusted through
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* the "factor" variable.
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* In any case, 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).
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*
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* 3. Compute the number of sample-data-blocks and ensure a minimum
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* of CPUM_SF_MIN_SDB. Also ensure the upper limit does not
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* exceed a "calculated" maximum. The symbolic maximum is
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* designed for basic-sampling only and needs to be increased if
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* diagnostic-sampling is active.
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* See also the remarks for these symbolic constants.
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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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factor = 1;
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n_sdb = DIV_ROUND_UP(freq, factor * ((PAGE_SIZE-64) / sample_size));
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if (n_sdb < CPUM_SF_MIN_SDB)
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n_sdb = CPUM_SF_MIN_SDB;
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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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"allocate_buffers: rate=%lu f=%lu sdb=%lu/%lu"
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" sample_size=%lu cpuhw=%p\n",
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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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*
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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);
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if (num)
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sfb_account_allocs(num, hwc);
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debug_sprintf_event(sfdbg, 5, "sfb: overflow: overflow=%llu ratio=%lu"
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" num=%lu\n", OVERFLOW_REG(hwc), ratio, num);
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OVERFLOW_REG(hwc) = 0;
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}
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/* extend_sampling_buffer() - Extend sampling buffer
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* @sfb: Sampling buffer structure (for local CPU)
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* @hwc: Perf event hardware structure
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*
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* Use this function to extend the sampling buffer based on the overflow counter
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* and postponed allocation extents stored in the specified Perf event hardware.
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*
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* Important: This function disables the sampling facility in order to safely
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* change the sampling buffer structure. Do not call this function
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* when the PMU is active.
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*/
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static void extend_sampling_buffer(struct sf_buffer *sfb,
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struct hw_perf_event *hwc)
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{
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unsigned long num, num_old;
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int rc;
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num = sfb_pending_allocs(sfb, hwc);
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if (!num)
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return;
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num_old = sfb->num_sdb;
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/* Disable the sampling facility to reset any states and also
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* clear pending measurement alerts.
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*/
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sf_disable();
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/* Extend the sampling buffer.
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* 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, "sfb: extend: realloc "
|
|
"failed with rc=%i\n", rc);
|
|
|
|
if (sfb_has_pending_allocs(sfb, hwc))
|
|
debug_sprintf_event(sfdbg, 5, "sfb: extend: "
|
|
"req=%lu alloc=%lu remaining=%lu\n",
|
|
num, sfb->num_sdb - num_old,
|
|
sfb_pending_allocs(sfb, hwc));
|
|
}
|
|
|
|
|
|
/* 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,
|
|
"setup_pmc_cpu: initialized: cpuhw=%p\n", 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,
|
|
"setup_pmc_cpu: released: cpuhw=%p\n", 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 void hw_reset_registers(struct hw_perf_event *hwc,
|
|
unsigned long *sdbt_origin)
|
|
{
|
|
/* (Re)set to first sample-data-block-table */
|
|
TEAR_REG(hwc) = (unsigned long) sdbt_origin;
|
|
}
|
|
|
|
static unsigned long hw_limit_rate(const struct hws_qsi_info_block *si,
|
|
unsigned long rate)
|
|
{
|
|
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, 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 int __hw_perf_event_init(struct perf_event *event)
|
|
{
|
|
struct cpu_hw_sf *cpuhw;
|
|
struct hws_qsi_info_block si;
|
|
struct perf_event_attr *attr = &event->attr;
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
unsigned long rate;
|
|
int cpu, err;
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/* 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;
|
|
|
|
/* The sampling information (si) contains information about the
|
|
* min/max sampling intervals and the CPU speed. So calculate the
|
|
* correct sampling interval and avoid the whole period adjust
|
|
* feedback loop.
|
|
*/
|
|
rate = 0;
|
|
if (attr->freq) {
|
|
if (!attr->sample_freq) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
rate = freq_to_sample_rate(&si, attr->sample_freq);
|
|
rate = hw_limit_rate(&si, rate);
|
|
attr->freq = 0;
|
|
attr->sample_period = rate;
|
|
} else {
|
|
/* The min/max sampling rates specifies the valid range
|
|
* of sample periods. If the specified sample period is
|
|
* out of range, limit the period to the range boundary.
|
|
*/
|
|
rate = hw_limit_rate(&si, hwc->sample_period);
|
|
|
|
/* The perf core maintains a maximum sample rate that is
|
|
* configurable through the sysctl interface. Ensure the
|
|
* sampling rate does not exceed this value. This also helps
|
|
* to avoid throttling when pushing samples with
|
|
* perf_event_overflow().
|
|
*/
|
|
if (sample_rate_to_freq(&si, rate) >
|
|
sysctl_perf_event_sample_rate) {
|
|
err = -EINVAL;
|
|
debug_sprintf_event(sfdbg, 1, "Sampling rate exceeds maximum perf sample rate\n");
|
|
goto out;
|
|
}
|
|
}
|
|
SAMPL_RATE(hwc) = rate;
|
|
hw_init_period(hwc, SAMPL_RATE(hwc));
|
|
|
|
/* Initialize sample data overflow accounting */
|
|
hwc->extra_reg.reg = REG_OVERFLOW;
|
|
OVERFLOW_REG(hwc) = 0;
|
|
|
|
/* 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 int cpumsf_pmu_event_init(struct perf_event *event)
|
|
{
|
|
int err;
|
|
|
|
/* No support for taken branch sampling */
|
|
if (has_branch_stack(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);
|
|
if (sfb_has_pending_allocs(&cpuhw->sfb, hwc))
|
|
extend_sampling_buffer(&cpuhw->sfb, hwc);
|
|
}
|
|
}
|
|
|
|
/* (Re)enable the PMU and sampling facility */
|
|
cpuhw->flags |= PMU_F_ENABLED;
|
|
barrier();
|
|
|
|
err = lsctl(&cpuhw->lsctl);
|
|
if (err) {
|
|
cpuhw->flags &= ~PMU_F_ENABLED;
|
|
pr_err("Loading sampling controls failed: op=%i err=%i\n",
|
|
1, err);
|
|
return;
|
|
}
|
|
|
|
/* Load current program parameter */
|
|
lpp(&S390_lowcore.lpp);
|
|
|
|
debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i ed=%i cd=%i "
|
|
"tear=%p dear=%p\n", cpuhw->lsctl.es, cpuhw->lsctl.cs,
|
|
cpuhw->lsctl.ed, cpuhw->lsctl.cd,
|
|
(void *) cpuhw->lsctl.tear, (void *) cpuhw->lsctl.dear);
|
|
}
|
|
|
|
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 */
|
|
if (!qsi(&si)) {
|
|
/* TEAR/DEAR values are valid only if the sampling facility is
|
|
* enabled. Note that cpumsf_pmu_disable() might be called even
|
|
* for a disabled sampling facility because cpumsf_pmu_enable()
|
|
* controls the enable/disable state.
|
|
*/
|
|
if (si.es) {
|
|
cpuhw->lsctl.tear = si.tear;
|
|
cpuhw->lsctl.dear = si.dear;
|
|
}
|
|
} else
|
|
debug_sprintf_event(sfdbg, 3, "cpumsf_pmu_disable: "
|
|
"qsi() failed with err=%i\n", err);
|
|
|
|
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);
|
|
}
|
|
|
|
static void debug_sample_entry(struct hws_basic_entry *sample,
|
|
struct hws_trailer_entry *te)
|
|
{
|
|
debug_sprintf_event(sfdbg, 4, "hw_collect_samples: Found unknown "
|
|
"sampling data entry: te->f=%i basic.def=%04x (%p)\n",
|
|
te->f, sample->def, sample);
|
|
}
|
|
|
|
/* hw_collect_samples() - Walk through a sample-data-block and collect samples
|
|
* @event: The perf event
|
|
* @sdbt: Sample-data-block table
|
|
* @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_sample_entry(sample, te);
|
|
/* 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, "hw_perf_event_update: sdbt=%p "
|
|
"overflow=%llu timestamp=0x%llx\n",
|
|
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;
|
|
|
|
/* If an event overflow happened, discard samples by
|
|
* processing any remaining sample-data-blocks.
|
|
*/
|
|
if (event_overflow)
|
|
flush_all = 1;
|
|
}
|
|
|
|
/* Account sample overflows in the event hardware structure */
|
|
if (sampl_overflow)
|
|
OVERFLOW_REG(hwc) = DIV_ROUND_UP(OVERFLOW_REG(hwc) +
|
|
sampl_overflow, 1 + num_sdb);
|
|
if (sampl_overflow || event_overflow)
|
|
debug_sprintf_event(sfdbg, 4, "hw_perf_event_update: "
|
|
"overflow stats: sample=%llu event=%llu\n",
|
|
sampl_overflow, event_overflow);
|
|
}
|
|
|
|
#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, "aux_output_end: collect %lx SDBs\n", i);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (range > AUX_SDB_NUM_EMPTY(aux)) {
|
|
range_scan = range - AUX_SDB_NUM_EMPTY(aux);
|
|
idx = aux->empty_mark + 1;
|
|
for (i = 0; i < range_scan; i++, idx++) {
|
|
te = aux_sdb_trailer(aux, idx);
|
|
te->flags = te->flags & ~SDB_TE_BUFFER_FULL_MASK;
|
|
te->flags = te->flags & ~SDB_TE_ALERT_REQ_MASK;
|
|
te->overflow = 0;
|
|
}
|
|
/* 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, "aux_output_begin: "
|
|
"head->alert_mark->empty_mark (num_alert, range)"
|
|
"[%lx -> %lx -> %lx] (%lx, %lx) "
|
|
"tear index %lx, tear %lx dear %lx\n",
|
|
aux->head, aux->alert_mark, aux->empty_mark,
|
|
AUX_SDB_NUM_ALERT(aux), range,
|
|
head / CPUM_SF_SDB_PER_TABLE,
|
|
cpuhw->lsctl.tear,
|
|
cpuhw->lsctl.dear);
|
|
|
|
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;
|
|
orig_overflow = te->overflow;
|
|
*overflow = orig_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;
|
|
struct hws_trailer_entry *te;
|
|
|
|
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 = 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;
|
|
|
|
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;
|
|
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, "AUX buffer used up\n");
|
|
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", num_sdb);
|
|
debug_sprintf_event(sfdbg, 1, "head %lx range %lx "
|
|
"overflow %llx\n",
|
|
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, "head %lx alert %lx "
|
|
"already full, try another\n",
|
|
aux->head, aux->alert_mark);
|
|
}
|
|
}
|
|
|
|
if (done)
|
|
debug_sprintf_event(sfdbg, 6, "aux_reset_buffer: "
|
|
"[%lx -> %lx -> %lx] (%lx, %lx)\n",
|
|
aux->head, aux->alert_mark, aux->empty_mark,
|
|
AUX_SDB_NUM_ALERT(aux), range);
|
|
}
|
|
|
|
/*
|
|
* 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, "aux_buffer_free: free "
|
|
"%lu SDBTs\n", num_sdbt);
|
|
}
|
|
|
|
static void aux_sdb_init(unsigned long sdb)
|
|
{
|
|
struct hws_trailer_entry *te;
|
|
|
|
te = (struct hws_trailer_entry *)trailer_entry_ptr(sdb);
|
|
|
|
/* Save clock base */
|
|
te->clock_base = 1;
|
|
memcpy(&te->progusage2, &tod_clock_base[1], 8);
|
|
}
|
|
|
|
/*
|
|
* 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 = kmalloc(sizeof(struct aux_buffer), GFP_KERNEL);
|
|
if (!aux)
|
|
goto no_aux;
|
|
sfb = &aux->sfb;
|
|
|
|
/* Allocate sdbt_index for fast reference */
|
|
n_sdbt = (nr_pages + CPUM_SF_SDB_PER_TABLE - 1) / CPUM_SF_SDB_PER_TABLE;
|
|
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, "aux_buffer_setup: setup %lu SDBTs"
|
|
" and %lu SDBs\n",
|
|
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 */
|
|
}
|
|
|
|
/* 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;
|
|
hw_reset_registers(&event->hw, 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,
|
|
};
|
|
|
|
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, "measurement alert: 0x%x\n", 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=x%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=%04x\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, 0640);
|