CRIS v32: Change lib/spinlock.S to use byte operations instead of dwords.
[linux-2.6.git] / arch / cris / kernel / profile.c
1 #include <linux/init.h>
2 #include <linux/errno.h>
3 #include <linux/kernel.h>
4 #include <linux/proc_fs.h>
5 #include <linux/types.h>
6 #include <asm/ptrace.h>
7 #include <asm/uaccess.h>
8
9 #define SAMPLE_BUFFER_SIZE 8192
10
11 static char* sample_buffer;
12 static char* sample_buffer_pos;
13 static int prof_running = 0;
14
15 void
16 cris_profile_sample(struct pt_regs* regs)
17 {
18         if (!prof_running)
19                 return;
20
21         if (user_mode(regs))
22                 *(unsigned int*)sample_buffer_pos = current->pid;
23         else
24                 *(unsigned int*)sample_buffer_pos = 0;
25
26         *(unsigned int*)(sample_buffer_pos + 4) = instruction_pointer(regs);
27         sample_buffer_pos += 8;
28
29         if (sample_buffer_pos == sample_buffer + SAMPLE_BUFFER_SIZE)
30                 sample_buffer_pos = sample_buffer;
31 }
32
33 static ssize_t
34 read_cris_profile(struct file *file, char __user *buf,
35                   size_t count, loff_t *ppos)
36 {
37         unsigned long p = *ppos;
38
39         if (p > SAMPLE_BUFFER_SIZE)
40                 return 0;
41
42         if (p + count > SAMPLE_BUFFER_SIZE)
43                 count = SAMPLE_BUFFER_SIZE - p;
44         if (copy_to_user(buf, sample_buffer + p,count))
45                 return -EFAULT;
46
47         memset(sample_buffer + p, 0, count);
48         *ppos += count;
49
50         return count;
51 }
52
53 static ssize_t
54 write_cris_profile(struct file *file, const char __user *buf,
55                    size_t count, loff_t *ppos)
56 {
57         sample_buffer_pos = sample_buffer;
58         memset(sample_buffer, 0, SAMPLE_BUFFER_SIZE);
59 }
60
61 static const struct file_operations cris_proc_profile_operations = {
62         .read           = read_cris_profile,
63         .write          = write_cris_profile,
64 };
65
66 static int
67 __init init_cris_profile(void)
68 {
69         struct proc_dir_entry *entry;
70
71         sample_buffer = kmalloc(SAMPLE_BUFFER_SIZE, GFP_KERNEL);
72         if (!sample_buffer) {
73                 return -ENOMEM;
74         }
75
76         sample_buffer_pos = sample_buffer;
77
78         entry = create_proc_entry("system_profile", S_IWUSR | S_IRUGO, NULL);
79         if (entry) {
80                 entry->proc_fops = &cris_proc_profile_operations;
81                 entry->size = SAMPLE_BUFFER_SIZE;
82         }
83         prof_running = 1;
84
85         return 0;
86 }
87
88 __initcall(init_cris_profile);