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Diffstat (limited to 'tools/perf/util/auxtrace.h')
| -rw-r--r-- | tools/perf/util/auxtrace.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h new file mode 100644 index 000000000000..2071b36560a0 --- /dev/null +++ b/tools/perf/util/auxtrace.h @@ -0,0 +1,117 @@ +/* + * auxtrace.h: AUX area trace support + * Copyright (c) 2013-2015, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + */ + +#ifndef __PERF_AUXTRACE_H +#define __PERF_AUXTRACE_H + +#include <sys/types.h> +#include <stdbool.h> + +#include <linux/perf_event.h> +#include <linux/types.h> + +#include "../perf.h" + +struct perf_evlist; + +/** + * struct auxtrace_mmap - records an mmap of the auxtrace buffer. + * @base: address of mapped area + * @userpg: pointer to buffer's perf_event_mmap_page + * @mask: %0 if @len is not a power of two, otherwise (@len - %1) + * @len: size of mapped area + * @prev: previous aux_head + * @idx: index of this mmap + * @tid: tid for a per-thread mmap (also set if there is only 1 tid on a per-cpu + * mmap) otherwise %0 + * @cpu: cpu number for a per-cpu mmap otherwise %-1 + */ +struct auxtrace_mmap { + void *base; + void *userpg; + size_t mask; + size_t len; + u64 prev; + int idx; + pid_t tid; + int cpu; +}; + +/** + * struct auxtrace_mmap_params - parameters to set up struct auxtrace_mmap. + * @mask: %0 if @len is not a power of two, otherwise (@len - %1) + * @offset: file offset of mapped area + * @len: size of mapped area + * @prot: mmap memory protection + * @idx: index of this mmap + * @tid: tid for a per-thread mmap (also set if there is only 1 tid on a per-cpu + * mmap) otherwise %0 + * @cpu: cpu number for a per-cpu mmap otherwise %-1 + */ +struct auxtrace_mmap_params { + size_t mask; + off_t offset; + size_t len; + int prot; + int idx; + pid_t tid; + int cpu; +}; + +static inline u64 auxtrace_mmap__read_head(struct auxtrace_mmap *mm) +{ + struct perf_event_mmap_page *pc = mm->userpg; +#if BITS_PER_LONG == 64 || !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT) + u64 head = ACCESS_ONCE(pc->aux_head); +#else + u64 head = __sync_val_compare_and_swap(&pc->aux_head, 0, 0); +#endif + + /* Ensure all reads are done after we read the head */ + rmb(); + return head; +} + +static inline void auxtrace_mmap__write_tail(struct auxtrace_mmap *mm, u64 tail) +{ + struct perf_event_mmap_page *pc = mm->userpg; +#if BITS_PER_LONG != 64 && defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT) + u64 old_tail; +#endif + + /* Ensure all reads are done before we write the tail out */ + mb(); +#if BITS_PER_LONG == 64 || !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT) + pc->aux_tail = tail; +#else + do { + old_tail = __sync_val_compare_and_swap(&pc->aux_tail, 0, 0); + } while (!__sync_bool_compare_and_swap(&pc->aux_tail, old_tail, tail)); +#endif +} + +int auxtrace_mmap__mmap(struct auxtrace_mmap *mm, + struct auxtrace_mmap_params *mp, + void *userpg, int fd); +void auxtrace_mmap__munmap(struct auxtrace_mmap *mm); +void auxtrace_mmap_params__init(struct auxtrace_mmap_params *mp, + off_t auxtrace_offset, + unsigned int auxtrace_pages, + bool auxtrace_overwrite); +void auxtrace_mmap_params__set_idx(struct auxtrace_mmap_params *mp, + struct perf_evlist *evlist, int idx, + bool per_cpu); + +#endif |