Ajay Mohan / Rasperf

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Commit fd96d80a4642a569bc01d4bfd7b11ab60591165b

Authored by Sathya Narayanan
1 parent 17110dd658
Exists in master

Adding driver files

Showing 3 changed files with 113 additions and 0 deletions Inline Diff

drivers/osproject.c View file @ fd96d80
File was created 1 /*
2 * * hello.c ­ The simplest kernel module.
3 * */
4 #include <linux/module.h>
5
6 #define ARMV7_PMNC_E (1 << 0) /* Enable all counters */
7 #define ARMV7_PMNC_P (1 << 1) /* Reset all counters */
8 #define ARMV7_PMNC_C (1 << 2) /* Cycle counter reset */
9 #define ARMV7_PMNC_D (1 << 3) /* CCNT counts every 64th cpu cycle */
10 #define ARMV7_PMNC_X (1 << 4) /* Export to ETM */
11 #define ARMV7_PMNC_DP (1 << 5) /* Disable CCNT if non-invasive debug*/
12 #define ARMV7_PMNC_N_SHIFT 11 /* Number of counters supported */
13 #define ARMV7_PMNC_N_MASK 0x1f
14 #define ARMV7_PMNC_MASK 0x3f /* Mask for writable bits */
15
16 /*101b9173
17 static u32 armv7_pmnc_read(void)
18 {
19 u32 val;
20 asm volatile("mrc p15, 0, %0, c9, c12, 0" : "=r"(val));
21 return val;
22 }
23
24 static void armv7_pmnc_write(u32 val)
25 {
26 val &= ARMV7_PMNC_MASK;
27 isb();
28 asm volatile("mcr p15, 0, %0, c9, c12, 0" :: "r"(val));
29 }
30 */
31
32 int init_module()
33 {
34 unsigned int regr;
35 unsigned int i;
36 unsigned int a, b;
37
38 asm volatile("mrc p15, 0, %0, c9, c14, 0" : "=r" (regr));
39 pr_info("regr: %x\n", regr);
40
41 regr = 0;
42 for (i = 0; i < 1000; i++) {
43 asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (a));
44 asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (b));
45 regr += b - a;
46 pr_info("overhead: %u\n", b - a);
47 }
drivers/osproject_syscall.c View file @ fd96d80
File was created 1 #include <linux/module.h>
2 #include <linux/sched.h>
3
4 int init_module()
5 {
6 unsigned int regr;
7 unsigned int i;
8 unsigned int a, b;
9
10 asm volatile("mrc p15, 0, %0, c9, c14, 0" : "=r" (regr));
11 pr_info("User access regr: %x\n", regr);
12
13 asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (a));
14 i = current->pid;
15 asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (b));
16
17 pr_info("PID: %u, Time for getpid: %u\n", i, b - a);
18 return 0;
drivers/osproject_task.c View file @ fd96d80
File was created 1 #include <stdio.h>
2
3 int main()
4 {
5 unsigned int regr;
6 unsigned int a, b;
7 unsigned int avg;
8 unsigned int pid;
9
10 asm volatile("mrc p15, 0, %0, c9, c14, 0" : "=r" (regr));
11 printf("regr: %x\n", regr);
12
13 for (regr = 0; regr < 100; regr++) {
14 asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (a));
15 asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (b));
16 regr += (b - a);
17 }
18
19 regr /= 100;
20 printf("Measurement overhead: %u\n", regr);
21 regr = 0;
22 while (regr < 100) {
23 asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (a));
24 pid = fork();
25 asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (b));
26 printf("Time for fork: %u\n", b - a);
27 avg += (b - a);
28 regr++;
29 kill(pid, SIGKILL);