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