xref: /openbmc/linux/drivers/gpu/drm/i915/i915_utils.c (revision 9b68f30b)
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 
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 	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 
54 void 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)
65 static unsigned int i915_probe_fail_count;
66 
67 int __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 
83 bool i915_error_injected(void)
84 {
85 	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
86 }
87 
88 #endif
89 
90 void 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 
99 void 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 
120 bool 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