2 * Copyright (C) ARM Limited 2010-2013. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
11 #include <trace/events/block.h>
16 #define BLOCK_TOTAL (BLOCK_RQ_RD+1)
18 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
19 #define EVENTWRITE REQ_RW
21 #define EVENTWRITE REQ_WRITE
24 static ulong block_rq_wr_enabled;
25 static ulong block_rq_rd_enabled;
26 static ulong block_rq_wr_key;
27 static ulong block_rq_rd_key;
28 static atomic_t blockCnt[BLOCK_TOTAL];
29 static int blockGet[BLOCK_TOTAL * 4];
31 GATOR_DEFINE_PROBE(block_rq_complete, TP_PROTO(struct request_queue *q, struct request *rq))
38 write = rq->cmd_flags & EVENTWRITE;
45 if (block_rq_wr_enabled) {
46 atomic_add(size, &blockCnt[BLOCK_RQ_WR]);
49 if (block_rq_rd_enabled) {
50 atomic_add(size, &blockCnt[BLOCK_RQ_RD]);
55 static int gator_events_block_create_files(struct super_block *sb, struct dentry *root)
59 /* block_complete_wr */
60 dir = gatorfs_mkdir(sb, root, "Linux_block_rq_wr");
64 gatorfs_create_ulong(sb, dir, "enabled", &block_rq_wr_enabled);
65 gatorfs_create_ro_ulong(sb, dir, "key", &block_rq_wr_key);
67 /* block_complete_rd */
68 dir = gatorfs_mkdir(sb, root, "Linux_block_rq_rd");
72 gatorfs_create_ulong(sb, dir, "enabled", &block_rq_rd_enabled);
73 gatorfs_create_ro_ulong(sb, dir, "key", &block_rq_rd_key);
78 static int gator_events_block_start(void)
80 // register tracepoints
81 if (block_rq_wr_enabled || block_rq_rd_enabled)
82 if (GATOR_REGISTER_TRACE(block_rq_complete))
83 goto fail_block_rq_exit;
84 pr_debug("gator: registered block event tracepoints\n");
88 // unregister tracepoints on error
90 pr_err("gator: block event tracepoints failed to activate, please verify that tracepoints are enabled in the linux kernel\n");
95 static void gator_events_block_stop(void)
97 if (block_rq_wr_enabled || block_rq_rd_enabled)
98 GATOR_UNREGISTER_TRACE(block_rq_complete);
99 pr_debug("gator: unregistered block event tracepoints\n");
101 block_rq_wr_enabled = 0;
102 block_rq_rd_enabled = 0;
105 static int gator_events_block_read(int **buffer)
107 int len, value, data = 0;
109 if (!on_primary_core()) {
114 if (block_rq_wr_enabled && (value = atomic_read(&blockCnt[BLOCK_RQ_WR])) > 0) {
115 atomic_sub(value, &blockCnt[BLOCK_RQ_WR]);
116 blockGet[len++] = block_rq_wr_key;
117 blockGet[len++] = 0; // indicates to Streamline that value bytes were written now, not since the last message
118 blockGet[len++] = block_rq_wr_key;
119 blockGet[len++] = value;
122 if (block_rq_rd_enabled && (value = atomic_read(&blockCnt[BLOCK_RQ_RD])) > 0) {
123 atomic_sub(value, &blockCnt[BLOCK_RQ_RD]);
124 blockGet[len++] = block_rq_rd_key;
125 blockGet[len++] = 0; // indicates to Streamline that value bytes were read now, not since the last message
126 blockGet[len++] = block_rq_rd_key;
127 blockGet[len++] = value;
137 static struct gator_interface gator_events_block_interface = {
138 .create_files = gator_events_block_create_files,
139 .start = gator_events_block_start,
140 .stop = gator_events_block_stop,
141 .read = gator_events_block_read,
144 int gator_events_block_init(void)
146 block_rq_wr_enabled = 0;
147 block_rq_rd_enabled = 0;
149 block_rq_wr_key = gator_events_get_key();
150 block_rq_rd_key = gator_events_get_key();
152 return gator_events_install(&gator_events_block_interface);
155 gator_events_init(gator_events_block_init);