LXR linux/drivers/gpu/drm/i915/i915

   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
  15void
  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
  54void 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)
  65static unsigned int i915_probe_fail_count;
  66
  67int __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
  83bool i915_error_injected(void)
  84{
  85        return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
  86}
  87
  88#endif
  89
  90void 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
  99void 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
 120bool 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}
 128