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
13void
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
52void 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)
63static unsigned int i915_probe_fail_count;
64
65int __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
81bool i915_error_injected(void)
82{
83	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
84}
85
86#endif
87
88void 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
97void 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}
117