drivers/gpu/drm/i915/i915_utils.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright © 2019 Intel Corporation
   4  */
   5
   6 #include <drm/drm_drv.h>
   7
   8 #include "i915_drv.h"
   9 #include "i915_utils.h"
  10
  11 #define FDO_BUG_MSG "Please file a bug on drm/i915; see " FDO_BUG_URL " for details."
  12
  13 void
  14 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
  15               const char *fmt, ...)
  16 {
  17         static bool shown_bug_once;
  18         struct device *kdev = dev_priv->drm.dev;
  19         bool is_error = level[1] <= KERN_ERR[1];
  20         bool is_debug = level[1] == KERN_DEBUG[1];
  21         struct va_format vaf;
  22         va_list args;
  23
  24         if (is_debug && !drm_debug_enabled(DRM_UT_DRIVER))
  25                 return;
  26
  27         va_start(args, fmt);
  28
  29         vaf.fmt = fmt;
  30         vaf.va = &args;
  31
  32         if (is_error)
  33                 dev_printk(level, kdev, "%pV", &vaf);
  34         else
  35                 dev_printk(level, kdev, "[" DRM_NAME ":%ps] %pV",
  36                            __builtin_return_address(0), &vaf);
  37
  38         va_end(args);
  39
  40         if (is_error && !shown_bug_once) {
  41                 /*
  42                  * Ask the user to file a bug report for the error, except
  43                  * if they may have caused the bug by fiddling with unsafe
  44                  * module parameters.
  45                  */
  46                 if (!test_taint(TAINT_USER))
  47                         dev_notice(kdev, "%s", FDO_BUG_MSG);
  48                 shown_bug_once = true;
  49         }
  50 }
  51
  52 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
  53 static unsigned int i915_probe_fail_count;
  54
  55 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
  56                               const char *func, int line)
  57 {
  58         if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
  59                 return 0;
  60
  61         if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
  62                 return 0;
  63
  64         __i915_printk(i915, KERN_INFO,
  65                       "Injecting failure %d at checkpoint %u [%s:%d]\n",
  66                       err, i915_modparams.inject_probe_failure, func, line);
  67         i915_modparams.inject_probe_failure = 0;
  68         return err;
  69 }
  70
  71 bool i915_error_injected(void)
  72 {
  73         return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
  74 }
  75
  76 #endif
  77
  78 void cancel_timer(struct timer_list *t)
  79 {
  80         if (!READ_ONCE(t->expires))
  81                 return;
  82
  83         del_timer(t);
  84         WRITE_ONCE(t->expires, 0);
  85 }
  86
  87 void set_timer_ms(struct timer_list *t, unsigned long timeout)
  88 {
  89         if (!timeout) {
  90                 cancel_timer(t);
  91                 return;
  92         }
  93
  94         timeout = msecs_to_jiffies_timeout(timeout);
  95
  96         /*
  97          * Paranoia to make sure the compiler computes the timeout before
  98          * loading 'jiffies' as jiffies is volatile and may be updated in
  99          * the background by a timer tick. All to reduce the complexity
 100          * of the addition and reduce the risk of losing a jiffie.
 101          */
 102         barrier();
 103
 104         mod_timer(t, jiffies + timeout);
 105 }