cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ring_buffer.h (7612B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _LINUX_RING_BUFFER_H
      3#define _LINUX_RING_BUFFER_H
      4
      5#include <linux/mm.h>
      6#include <linux/seq_file.h>
      7#include <linux/poll.h>
      8
      9struct trace_buffer;
     10struct ring_buffer_iter;
     11
     12/*
     13 * Don't refer to this struct directly, use functions below.
     14 */
     15struct ring_buffer_event {
     16	u32		type_len:5, time_delta:27;
     17
     18	u32		array[];
     19};
     20
     21/**
     22 * enum ring_buffer_type - internal ring buffer types
     23 *
     24 * @RINGBUF_TYPE_PADDING:	Left over page padding or discarded event
     25 *				 If time_delta is 0:
     26 *				  array is ignored
     27 *				  size is variable depending on how much
     28 *				  padding is needed
     29 *				 If time_delta is non zero:
     30 *				  array[0] holds the actual length
     31 *				  size = 4 + length (bytes)
     32 *
     33 * @RINGBUF_TYPE_TIME_EXTEND:	Extend the time delta
     34 *				 array[0] = time delta (28 .. 59)
     35 *				 size = 8 bytes
     36 *
     37 * @RINGBUF_TYPE_TIME_STAMP:	Absolute timestamp
     38 *				 Same format as TIME_EXTEND except that the
     39 *				 value is an absolute timestamp, not a delta
     40 *				 event.time_delta contains bottom 27 bits
     41 *				 array[0] = top (28 .. 59) bits
     42 *				 size = 8 bytes
     43 *
     44 * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
     45 *				Data record
     46 *				 If type_len is zero:
     47 *				  array[0] holds the actual length
     48 *				  array[1..(length+3)/4] holds data
     49 *				  size = 4 + length (bytes)
     50 *				 else
     51 *				  length = type_len << 2
     52 *				  array[0..(length+3)/4-1] holds data
     53 *				  size = 4 + length (bytes)
     54 */
     55enum ring_buffer_type {
     56	RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28,
     57	RINGBUF_TYPE_PADDING,
     58	RINGBUF_TYPE_TIME_EXTEND,
     59	RINGBUF_TYPE_TIME_STAMP,
     60};
     61
     62unsigned ring_buffer_event_length(struct ring_buffer_event *event);
     63void *ring_buffer_event_data(struct ring_buffer_event *event);
     64u64 ring_buffer_event_time_stamp(struct trace_buffer *buffer,
     65				 struct ring_buffer_event *event);
     66
     67/*
     68 * ring_buffer_discard_commit will remove an event that has not
     69 *   been committed yet. If this is used, then ring_buffer_unlock_commit
     70 *   must not be called on the discarded event. This function
     71 *   will try to remove the event from the ring buffer completely
     72 *   if another event has not been written after it.
     73 *
     74 * Example use:
     75 *
     76 *  if (some_condition)
     77 *    ring_buffer_discard_commit(buffer, event);
     78 *  else
     79 *    ring_buffer_unlock_commit(buffer, event);
     80 */
     81void ring_buffer_discard_commit(struct trace_buffer *buffer,
     82				struct ring_buffer_event *event);
     83
     84/*
     85 * size is in bytes for each per CPU buffer.
     86 */
     87struct trace_buffer *
     88__ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key);
     89
     90/*
     91 * Because the ring buffer is generic, if other users of the ring buffer get
     92 * traced by ftrace, it can produce lockdep warnings. We need to keep each
     93 * ring buffer's lock class separate.
     94 */
     95#define ring_buffer_alloc(size, flags)			\
     96({							\
     97	static struct lock_class_key __key;		\
     98	__ring_buffer_alloc((size), (flags), &__key);	\
     99})
    100
    101int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full);
    102__poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
    103			  struct file *filp, poll_table *poll_table);
    104
    105
    106#define RING_BUFFER_ALL_CPUS -1
    107
    108void ring_buffer_free(struct trace_buffer *buffer);
    109
    110int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, int cpu);
    111
    112void ring_buffer_change_overwrite(struct trace_buffer *buffer, int val);
    113
    114struct ring_buffer_event *ring_buffer_lock_reserve(struct trace_buffer *buffer,
    115						   unsigned long length);
    116int ring_buffer_unlock_commit(struct trace_buffer *buffer,
    117			      struct ring_buffer_event *event);
    118int ring_buffer_write(struct trace_buffer *buffer,
    119		      unsigned long length, void *data);
    120
    121void ring_buffer_nest_start(struct trace_buffer *buffer);
    122void ring_buffer_nest_end(struct trace_buffer *buffer);
    123
    124struct ring_buffer_event *
    125ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts,
    126		 unsigned long *lost_events);
    127struct ring_buffer_event *
    128ring_buffer_consume(struct trace_buffer *buffer, int cpu, u64 *ts,
    129		    unsigned long *lost_events);
    130
    131struct ring_buffer_iter *
    132ring_buffer_read_prepare(struct trace_buffer *buffer, int cpu, gfp_t flags);
    133void ring_buffer_read_prepare_sync(void);
    134void ring_buffer_read_start(struct ring_buffer_iter *iter);
    135void ring_buffer_read_finish(struct ring_buffer_iter *iter);
    136
    137struct ring_buffer_event *
    138ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts);
    139void ring_buffer_iter_advance(struct ring_buffer_iter *iter);
    140void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
    141int ring_buffer_iter_empty(struct ring_buffer_iter *iter);
    142bool ring_buffer_iter_dropped(struct ring_buffer_iter *iter);
    143
    144unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu);
    145
    146void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu);
    147void ring_buffer_reset_online_cpus(struct trace_buffer *buffer);
    148void ring_buffer_reset(struct trace_buffer *buffer);
    149
    150#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
    151int ring_buffer_swap_cpu(struct trace_buffer *buffer_a,
    152			 struct trace_buffer *buffer_b, int cpu);
    153#else
    154static inline int
    155ring_buffer_swap_cpu(struct trace_buffer *buffer_a,
    156		     struct trace_buffer *buffer_b, int cpu)
    157{
    158	return -ENODEV;
    159}
    160#endif
    161
    162bool ring_buffer_empty(struct trace_buffer *buffer);
    163bool ring_buffer_empty_cpu(struct trace_buffer *buffer, int cpu);
    164
    165void ring_buffer_record_disable(struct trace_buffer *buffer);
    166void ring_buffer_record_enable(struct trace_buffer *buffer);
    167void ring_buffer_record_off(struct trace_buffer *buffer);
    168void ring_buffer_record_on(struct trace_buffer *buffer);
    169bool ring_buffer_record_is_on(struct trace_buffer *buffer);
    170bool ring_buffer_record_is_set_on(struct trace_buffer *buffer);
    171void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu);
    172void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu);
    173
    174u64 ring_buffer_oldest_event_ts(struct trace_buffer *buffer, int cpu);
    175unsigned long ring_buffer_bytes_cpu(struct trace_buffer *buffer, int cpu);
    176unsigned long ring_buffer_entries(struct trace_buffer *buffer);
    177unsigned long ring_buffer_overruns(struct trace_buffer *buffer);
    178unsigned long ring_buffer_entries_cpu(struct trace_buffer *buffer, int cpu);
    179unsigned long ring_buffer_overrun_cpu(struct trace_buffer *buffer, int cpu);
    180unsigned long ring_buffer_commit_overrun_cpu(struct trace_buffer *buffer, int cpu);
    181unsigned long ring_buffer_dropped_events_cpu(struct trace_buffer *buffer, int cpu);
    182unsigned long ring_buffer_read_events_cpu(struct trace_buffer *buffer, int cpu);
    183
    184u64 ring_buffer_time_stamp(struct trace_buffer *buffer);
    185void ring_buffer_normalize_time_stamp(struct trace_buffer *buffer,
    186				      int cpu, u64 *ts);
    187void ring_buffer_set_clock(struct trace_buffer *buffer,
    188			   u64 (*clock)(void));
    189void ring_buffer_set_time_stamp_abs(struct trace_buffer *buffer, bool abs);
    190bool ring_buffer_time_stamp_abs(struct trace_buffer *buffer);
    191
    192size_t ring_buffer_nr_pages(struct trace_buffer *buffer, int cpu);
    193size_t ring_buffer_nr_dirty_pages(struct trace_buffer *buffer, int cpu);
    194
    195void *ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu);
    196void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data);
    197int ring_buffer_read_page(struct trace_buffer *buffer, void **data_page,
    198			  size_t len, int cpu, int full);
    199
    200struct trace_seq;
    201
    202int ring_buffer_print_entry_header(struct trace_seq *s);
    203int ring_buffer_print_page_header(struct trace_seq *s);
    204
    205enum ring_buffer_flags {
    206	RB_FL_OVERWRITE		= 1 << 0,
    207};
    208
    209#ifdef CONFIG_RING_BUFFER
    210int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node);
    211#else
    212#define trace_rb_cpu_prepare	NULL
    213#endif
    214
    215#endif /* _LINUX_RING_BUFFER_H */