overlay/gem-interrupts.c

   1 /*
   2  * Copyright © 2013 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  */
  24
  25 #include <sys/stat.h>
  26 #include <unistd.h>
  27 #include <fcntl.h>
  28 #include <errno.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <ctype.h>
  33
  34 #include "igt_perf.h"
  35
  36 #include "gem-interrupts.h"
  37 #include "debugfs.h"
  38
  39 static long long debugfs_read(void)
  40 {
  41         char buf[8192], *b;
  42         int fd, len;
  43
  44         sprintf(buf, "%s/i915_gem_interrupt", debugfs_dri_path);
  45         fd = open(buf, 0);
  46         if (fd < 0)
  47                 return -1;
  48
  49         len = read(fd, buf, sizeof(buf)-1);
  50         close(fd);
  51
  52         if (len < 0)
  53                 return -1;
  54
  55         buf[len] = '\0';
  56
  57         b = strstr(buf, "Interrupts received:");
  58         if (b == NULL)
  59                 return -1;
  60
  61         return strtoull(b + sizeof("Interrupts received:"), 0, 0);
  62 }
  63
  64 static long long procfs_read(void)
  65 {
  66         char buf[8192], *b;
  67         int fd, len;
  68         unsigned long long val;
  69
  70 /* 44:         51      42446          0          0   PCI-MSI-edge      i915*/
  71         fd = open("/proc/interrupts", 0);
  72         if (fd < 0)
  73                 return -1;
  74
  75         len = read(fd, buf, sizeof(buf)-1);
  76         close(fd);
  77
  78         if (len < 0)
  79                 return -1;
  80
  81         buf[len] = '\0';
  82
  83         b = strstr(buf, "i915");
  84         if (b == NULL)
  85                 return -1;
  86         while (*--b != ':')
  87                 ;
  88
  89         val = 0;
  90         do {
  91                 while (isspace(*++b))
  92                         ;
  93                 if (!isdigit(*b))
  94                         break;
  95
  96                 val += strtoull(b, &b, 0);
  97         } while(1);
  98
  99         return val;
 100 }
 101
 102 static long long interrupts_read(void)
 103 {
 104         long long val;
 105
 106         val = debugfs_read();
 107         if (val < 0)
 108                 val = procfs_read();
 109         return val;
 110 }
 111
 112 int gem_interrupts_init(struct gem_interrupts *irqs)
 113 {
 114         memset(irqs, 0, sizeof(*irqs));
 115
 116         irqs->fd = perf_igfx_open(I915_PMU_INTERRUPTS);
 117         if (irqs->fd < 0 && interrupts_read() < 0)
 118                 irqs->error = ENODEV;
 119
 120         return irqs->error;
 121 }
 122
 123 int gem_interrupts_update(struct gem_interrupts *irqs)
 124 {
 125         uint64_t val;
 126         int update;
 127
 128         if (irqs->error)
 129                 return irqs->error;
 130
 131         if (irqs->fd < 0) {
 132                 long long ret;
 133                 ret = interrupts_read();
 134                 if (ret < 0)
 135                         return irqs->error = ENODEV;
 136                 else
 137                         val = ret;
 138         } else {
 139                 uint64_t data[2];
 140
 141                 if (read(irqs->fd, data, sizeof(data)) < 0)
 142                         return irqs->error = errno;
 143
 144                 val = data[0];
 145         }
 146
 147         update = irqs->last_count == 0;
 148         irqs->last_count = irqs->count;
 149         irqs->count = val;
 150         irqs->delta = irqs->count - irqs->last_count;
 151         return update ? EAGAIN : 0;
 152 }