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}