drivers/gpu/drm/i915/i915_utils.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright © 2019 Intel Corporation
   4  */
   5
   6 #include <linux/device.h>
   7
   8 #include <drm/drm_drv.h>
   9
  10 #include "i915_drv.h"
  11 #include "i915_utils.h"
  12
  13 #define FDO_BUG_MSG "Please file a bug on drm/i915; see " FDO_BUG_URL " for details."
  14
  15 void
  16 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
  17               const char *fmt, ...)
  18 {
  19         static bool shown_bug_once;
  20         struct device *kdev = dev_priv->drm.dev;
  21         bool is_error = level[1] <= KERN_ERR[1];
  22         bool is_debug = level[1] == KERN_DEBUG[1];
  23         struct va_format vaf;
  24         va_list args;
  25
  26         if (is_debug && !drm_debug_enabled(DRM_UT_DRIVER))
  27                 return;
  28
  29         va_start(args, fmt);
  30
  31         vaf.fmt = fmt;
  32         vaf.va = &args;
  33
  34         if (is_error)
  35                 dev_printk(level, kdev, "%pV", &vaf);
  36         else
  37                 dev_printk(level, kdev, "[" DRM_NAME ":%ps] %pV",
  38                            __builtin_return_address(0), &vaf);
  39
  40         va_end(args);
  41
  42         if (is_error && !shown_bug_once) {
  43                 /*
  44                  * Ask the user to file a bug report for the error, except
  45                  * if they may have caused the bug by fiddling with unsafe
  46                  * module parameters.
  47                  */
  48                 if (!test_taint(TAINT_USER))
  49                         dev_notice(kdev, "%s", FDO_BUG_MSG);
  50                 shown_bug_once = true;
  51         }
  52 }
  53
  54 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
  55 {
  56         __i915_printk(i915, KERN_NOTICE, "CI tainted:%#x by %pS\n",
  57                       taint, (void *)_RET_IP_);
  58
  59         /* Failures that occur during fault injection testing are expected */
  60         if (!i915_error_injected())
  61                 __add_taint_for_CI(taint);
  62 }
  63
  64 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
  65 static unsigned int i915_probe_fail_count;
  66
  67 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
  68                               const char *func, int line)
  69 {
  70         if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
  71                 return 0;
  72
  73         if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
  74                 return 0;
  75
  76         __i915_printk(i915, KERN_INFO,
  77                       "Injecting failure %d at checkpoint %u [%s:%d]\n",
  78                       err, i915_modparams.inject_probe_failure, func, line);
  79         i915_modparams.inject_probe_failure = 0;
  80         return err;
  81 }
  82
  83 bool i915_error_injected(void)
  84 {
  85         return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
  86 }
  87
  88 #endif
  89
  90 void cancel_timer(struct timer_list *t)
  91 {
  92         if (!timer_active(t))
  93                 return;
  94
  95         del_timer(t);
  96         WRITE_ONCE(t->expires, 0);
  97 }
  98
  99 void set_timer_ms(struct timer_list *t, unsigned long timeout)
 100 {
 101         if (!timeout) {
 102                 cancel_timer(t);
 103                 return;
 104         }
 105
 106         timeout = msecs_to_jiffies(timeout);
 107
 108         /*
 109          * Paranoia to make sure the compiler computes the timeout before
 110          * loading 'jiffies' as jiffies is volatile and may be updated in
 111          * the background by a timer tick. All to reduce the complexity
 112          * of the addition and reduce the risk of losing a jiffie.
 113          */
 114         barrier();
 115
 116         /* Keep t->expires = 0 reserved to indicate a canceled timer. */
 117         mod_timer(t, jiffies + timeout ?: 1);
 118 }
 119
 120 bool i915_vtd_active(struct drm_i915_private *i915)
 121 {
 122         if (device_iommu_mapped(i915->drm.dev))
 123                 return true;
 124
 125         /* Running as a guest, we assume the host is enforcing VT'd */
 126         return i915_run_as_guest();
 127 }