gator: ARM DS-5.6 Streamline gator driver
[android-sdk/arm-ds5-gator.git] / gator_events_block.c
1 /**
2  * Copyright (C) ARM Limited 2010-2011. All rights reserved.
3  *
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.
7  *
8  */
10 #include "gator.h"
11 #include <trace/events/block.h>
13 #define BLOCK_RQ_WR             0
14 #define BLOCK_RQ_RD             1
16 #define BLOCK_TOTAL             (BLOCK_RQ_RD+1)
18 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
19 #define EVENTWRITE REQ_RW
20 #else
21 #define EVENTWRITE REQ_WRITE
22 #endif
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 DEFINE_PER_CPU(int[BLOCK_TOTAL], blockCnt);
29 static DEFINE_PER_CPU(int[BLOCK_TOTAL * 2], blockGet);
30 static DEFINE_PER_CPU(bool, new_data_avail);
32 GATOR_DEFINE_PROBE(block_rq_complete, TP_PROTO(struct request_queue *q, struct request *rq))
33 {
34         unsigned long flags;
35         int write, size;
36         int cpu = smp_processor_id();
38         if (!rq)
39                 return;
41         write = rq->cmd_flags & EVENTWRITE;
42         size = rq->resid_len;
44         if (!size)
45                 return;
47         // disable interrupts to synchronize with gator_events_block_read()
48         // spinlocks not needed since percpu buffers are used
49         local_irq_save(flags);
50         if (write)
51                 per_cpu(blockCnt, cpu)[BLOCK_RQ_WR] += size;
52         else
53                 per_cpu(blockCnt, cpu)[BLOCK_RQ_RD] += size;
54         local_irq_restore(flags);
56         per_cpu(new_data_avail, cpu) = true;
57 }
59 static int gator_events_block_create_files(struct super_block *sb, struct dentry *root)
60 {
61         struct dentry *dir;
63         /* block_complete_wr */
64         dir = gatorfs_mkdir(sb, root, "Linux_block_rq_wr");
65         if (!dir) {
66                 return -1;
67         }
68         gatorfs_create_ulong(sb, dir, "enabled", &block_rq_wr_enabled);
69         gatorfs_create_ro_ulong(sb, dir, "key", &block_rq_wr_key);
71         /* block_complete_rd */
72         dir = gatorfs_mkdir(sb, root, "Linux_block_rq_rd");
73         if (!dir) {
74                 return -1;
75         }
76         gatorfs_create_ulong(sb, dir, "enabled", &block_rq_rd_enabled);
77         gatorfs_create_ro_ulong(sb, dir, "key", &block_rq_rd_key);
79         return 0;
80 }
82 static int gator_events_block_start(void)
83 {
84         int cpu;
86         for_each_present_cpu(cpu) 
87                 per_cpu(new_data_avail, cpu) = true;
89         // register tracepoints
90         if (block_rq_wr_enabled || block_rq_rd_enabled)
91                 if (GATOR_REGISTER_TRACE(block_rq_complete))
92                         goto fail_block_rq_exit;
93         pr_debug("gator: registered block event tracepoints\n");
95         return 0;
97         // unregister tracepoints on error
98 fail_block_rq_exit:
99         pr_err("gator: block event tracepoints failed to activate, please verify that tracepoints are enabled in the linux kernel\n");
101         return -1;
104 static void gator_events_block_stop(void)
106         if (block_rq_wr_enabled || block_rq_rd_enabled)
107                 GATOR_UNREGISTER_TRACE(block_rq_complete);
108         pr_debug("gator: unregistered block event tracepoints\n");
110         block_rq_wr_enabled = 0;
111         block_rq_rd_enabled = 0;
114 static int gator_events_block_read(int **buffer)
116         unsigned long flags;
117         int len, value, cpu, data = 0;
118         cpu = smp_processor_id();
120         if (per_cpu(new_data_avail, cpu) == false)
121                 return 0;
123         per_cpu(new_data_avail, cpu) = false;
125         len = 0;
126         if (block_rq_wr_enabled) {
127                 local_irq_save(flags);
128                 value = per_cpu(blockCnt, cpu)[BLOCK_RQ_WR];
129                 per_cpu(blockCnt, cpu)[BLOCK_RQ_WR] = 0;
130                 local_irq_restore(flags);
131                 per_cpu(blockGet, cpu)[len++] = block_rq_wr_key;
132                 per_cpu(blockGet, cpu)[len++] = value;
133                 data += value;
134         }
135         if (block_rq_rd_enabled) {
136                 local_irq_save(flags);
137                 value = per_cpu(blockCnt, cpu)[BLOCK_RQ_RD];
138                 per_cpu(blockCnt, cpu)[BLOCK_RQ_RD] = 0;
139                 local_irq_restore(flags);
140                 per_cpu(blockGet, cpu)[len++] = block_rq_rd_key;
141                 per_cpu(blockGet, cpu)[len++] = value;
142                 data += value;
143         }
145         if (data != 0)
146                 per_cpu(new_data_avail, cpu) = true;
148         if (buffer)
149                 *buffer = per_cpu(blockGet, cpu);
151         return len;
154 static struct gator_interface gator_events_block_interface = {
155         .create_files = gator_events_block_create_files,
156         .start = gator_events_block_start,
157         .stop = gator_events_block_stop,
158         .read = gator_events_block_read,
159 };
161 int gator_events_block_init(void)
163         block_rq_wr_enabled = 0;
164         block_rq_rd_enabled = 0;
166         block_rq_wr_key = gator_events_get_key();
167         block_rq_rd_key = gator_events_get_key();
169         return gator_events_install(&gator_events_block_interface);
171 gator_events_init(gator_events_block_init);