xref: /openbsd-src/sys/dev/pci/drm/i915/i915_utils.c (revision 4e1ee0786f11cc571bd0be17d38e46f635c719fc)
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 #include <sys/syslog.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 #ifdef __linux__
35 	if (is_error)
36 		dev_printk(level, kdev, "%pV", &vaf);
37 	else
38 		dev_printk(level, kdev, "[" DRM_NAME ":%ps] %pV",
39 			   __builtin_return_address(0), &vaf);
40 #else
41 	if (!is_error)
42 		printf("[" DRM_NAME "] ");
43 	vprintf(fmt, args);
44 #endif
45 
46 	va_end(args);
47 
48 	if (is_error && !shown_bug_once) {
49 		/*
50 		 * Ask the user to file a bug report for the error, except
51 		 * if they may have caused the bug by fiddling with unsafe
52 		 * module parameters.
53 		 */
54 #ifdef __linux__
55 		if (!test_taint(TAINT_USER))
56 			dev_notice(kdev, "%s", FDO_BUG_MSG);
57 #endif
58 		shown_bug_once = true;
59 	}
60 }
61 
62 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
63 {
64 	__i915_printk(i915, KERN_NOTICE, "CI tainted:%#x by %pS\n",
65 		      taint, (void *)_RET_IP_);
66 
67 	/* Failures that occur during fault injection testing are expected */
68 	if (!i915_error_injected())
69 		__add_taint_for_CI(taint);
70 }
71 
72 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
73 static unsigned int i915_probe_fail_count;
74 
75 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
76 			      const char *func, int line)
77 {
78 	if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
79 		return 0;
80 
81 	if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
82 		return 0;
83 
84 	__i915_printk(i915, KERN_INFO,
85 		      "Injecting failure %d at checkpoint %u [%s:%d]\n",
86 		      err, i915_modparams.inject_probe_failure, func, line);
87 	i915_modparams.inject_probe_failure = 0;
88 	return err;
89 }
90 
91 bool i915_error_injected(void)
92 {
93 	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
94 }
95 
96 #endif
97 
98 void cancel_timer(struct timeout *t)
99 {
100 	if (!READ_ONCE(t->to_time))
101 		return;
102 
103 	del_timer(t);
104 	WRITE_ONCE(t->to_time, 0);
105 }
106 
107 void set_timer_ms(struct timeout *t, unsigned long timeout)
108 {
109 	if (!timeout) {
110 		cancel_timer(t);
111 		return;
112 	}
113 
114 	timeout = msecs_to_jiffies(timeout);
115 
116 	/*
117 	 * Paranoia to make sure the compiler computes the timeout before
118 	 * loading 'jiffies' as jiffies is volatile and may be updated in
119 	 * the background by a timer tick. All to reduce the complexity
120 	 * of the addition and reduce the risk of losing a jiffie.
121 	 */
122 	barrier();
123 
124 	/* Keep t->expires = 0 reserved to indicate a canceled timer. */
125 	mod_timer(t, jiffies + timeout ?: 1);
126 }
127