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 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
  53 {
  54         __i915_printk(i915, KERN_NOTICE, "CI tainted:%#x by %pS\n",
  55                       taint, (void *)_RET_IP_);
  56
  57         /* Failures that occur during fault injection testing are expected */
  58         if (!i915_error_injected())
  59                 __add_taint_for_CI(taint);
  60 }
  61
  62 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
  63 static unsigned int i915_probe_fail_count;
  64
  65 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
  66                               const char *func, int line)
  67 {
  68         if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
  69                 return 0;
  70
  71         if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
  72                 return 0;
  73
  74         __i915_printk(i915, KERN_INFO,
  75                       "Injecting failure %d at checkpoint %u [%s:%d]\n",
  76                       err, i915_modparams.inject_probe_failure, func, line);
  77         i915_modparams.inject_probe_failure = 0;
  78         return err;
  79 }
  80
  81 bool i915_error_injected(void)
  82 {
  83         return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
  84 }
  85
  86 #endif
  87
  88 void cancel_timer(struct timer_list *t)
  89 {
  90         if (!READ_ONCE(t->expires))
  91                 return;
  92
  93         del_timer(t);
  94         WRITE_ONCE(t->expires, 0);
  95 }
  96
  97 void set_timer_ms(struct timer_list *t, unsigned long timeout)
  98 {
  99         if (!timeout) {
 100                 cancel_timer(t);
 101                 return;
 102         }
 103
 104         timeout = msecs_to_jiffies(timeout);
 105
 106         /*
 107          * Paranoia to make sure the compiler computes the timeout before
 108          * loading 'jiffies' as jiffies is volatile and may be updated in
 109          * the background by a timer tick. All to reduce the complexity
 110          * of the addition and reduce the risk of losing a jiffie.
 111          */
 112         barrier();
 113
 114         /* Keep t->expires = 0 reserved to indicate a canceled timer. */
 115         mod_timer(t, jiffies + timeout ?: 1);
 116 }