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b5304713 MD |
1 | /* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only) |
2 | * | |
3 | * lib/ringbuffer/backend_types.h | |
4 | * | |
5 | * Ring buffer backend (types). | |
6 | * | |
7 | * Copyright (C) 2008-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
8 | */ | |
9 | ||
10 | #ifndef _LIB_RING_BUFFER_BACKEND_TYPES_H | |
11 | #define _LIB_RING_BUFFER_BACKEND_TYPES_H | |
12 | ||
13 | #include <linux/cpumask.h> | |
14 | #include <linux/types.h> | |
15 | #include <lttng/lttng-kernel-version.h> | |
16 | #include <lttng/lttng-cpuhotplug.h> | |
17 | ||
18 | struct lib_ring_buffer_backend_page { | |
19 | void *virt; /* page virtual address (cached) */ | |
20 | unsigned long pfn; /* page frame number */ | |
21 | }; | |
22 | ||
23 | struct lib_ring_buffer_backend_pages { | |
24 | unsigned long mmap_offset; /* offset of the subbuffer in mmap */ | |
25 | union v_atomic records_commit; /* current records committed count */ | |
26 | union v_atomic records_unread; /* records to read */ | |
27 | unsigned long data_size; /* Amount of data to read from subbuf */ | |
28 | struct lib_ring_buffer_backend_page p[]; | |
29 | }; | |
30 | ||
31 | struct lib_ring_buffer_backend_subbuffer { | |
32 | /* Identifier for subbuf backend pages. Exchanged atomically. */ | |
33 | unsigned long id; /* backend subbuffer identifier */ | |
34 | }; | |
35 | ||
36 | struct lib_ring_buffer_backend_counts { | |
37 | /* | |
38 | * Counter specific to the sub-buffer location within the ring buffer. | |
39 | * The actual sequence number of the packet within the entire ring | |
40 | * buffer can be derived from the formula nr_subbuffers * seq_cnt + | |
41 | * subbuf_idx. | |
42 | */ | |
43 | uint64_t seq_cnt; /* packet sequence number */ | |
44 | }; | |
45 | ||
46 | /* | |
47 | * Forward declaration of frontend-specific channel and ring_buffer. | |
48 | */ | |
49 | struct channel; | |
50 | struct lib_ring_buffer; | |
51 | ||
52 | struct lib_ring_buffer_backend { | |
53 | /* Array of ring_buffer_backend_subbuffer for writer */ | |
54 | struct lib_ring_buffer_backend_subbuffer *buf_wsb; | |
55 | /* ring_buffer_backend_subbuffer for reader */ | |
56 | struct lib_ring_buffer_backend_subbuffer buf_rsb; | |
57 | /* Array of lib_ring_buffer_backend_counts for the packet counter */ | |
58 | struct lib_ring_buffer_backend_counts *buf_cnt; | |
59 | /* | |
60 | * Pointer array of backend pages, for whole buffer. | |
61 | * Indexed by ring_buffer_backend_subbuffer identifier (id) index. | |
62 | */ | |
63 | struct lib_ring_buffer_backend_pages **array; | |
64 | unsigned int num_pages_per_subbuf; | |
65 | ||
66 | struct channel *chan; /* Associated channel */ | |
67 | int cpu; /* This buffer's cpu. -1 if global. */ | |
68 | union v_atomic records_read; /* Number of records read */ | |
69 | unsigned int allocated:1; /* is buffer allocated ? */ | |
70 | }; | |
71 | ||
72 | struct channel_backend { | |
73 | unsigned long buf_size; /* Size of the buffer */ | |
74 | unsigned long subbuf_size; /* Sub-buffer size */ | |
75 | unsigned int subbuf_size_order; /* Order of sub-buffer size */ | |
76 | unsigned int num_subbuf_order; /* | |
77 | * Order of number of sub-buffers/buffer | |
78 | * for writer. | |
79 | */ | |
80 | unsigned int buf_size_order; /* Order of buffer size */ | |
81 | unsigned int extra_reader_sb:1; /* has extra reader subbuffer ? */ | |
82 | struct lib_ring_buffer *buf; /* Channel per-cpu buffers */ | |
83 | ||
84 | unsigned long num_subbuf; /* Number of sub-buffers for writer */ | |
85 | u64 start_tsc; /* Channel creation TSC value */ | |
86 | void *priv; /* Client-specific information */ | |
87 | void *priv_ops; /* Client-specific ops pointer */ | |
88 | void (*release_priv_ops)(void *priv_ops); | |
89 | struct lttng_cpuhp_node cpuhp_prepare; /* CPU hotplug prepare */ | |
90 | /* | |
91 | * We need to copy config because the module containing the | |
92 | * source config can vanish before the last reference to this | |
93 | * channel's streams is released. | |
94 | */ | |
95 | struct lib_ring_buffer_config config; /* Ring buffer configuration */ | |
96 | cpumask_var_t cpumask; /* Allocated per-cpu buffers cpumask */ | |
97 | char name[NAME_MAX]; /* Channel name */ | |
98 | }; | |
99 | ||
100 | #endif /* _LIB_RING_BUFFER_BACKEND_TYPES_H */ |