xref: /openbsd/sys/dev/pci/drm/i915/i915_utils.c (revision 6c50df30)
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_reg.h"
12 #include "i915_utils.h"
13 
14 #include <sys/syslog.h>
15 
16 #define FDO_BUG_MSG "Please file a bug on drm/i915; see " FDO_BUG_URL " for details."
17 
18 void
__i915_printk(struct drm_i915_private * dev_priv,const char * level,const char * fmt,...)19 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
20 	      const char *fmt, ...)
21 {
22 	static bool shown_bug_once;
23 	struct device *kdev = dev_priv->drm.dev;
24 	bool is_error = level[1] <= KERN_ERR[1];
25 	bool is_debug = level[1] == KERN_DEBUG[1];
26 	struct va_format vaf;
27 	va_list args;
28 
29 	if (is_debug && !drm_debug_enabled(DRM_UT_DRIVER))
30 		return;
31 
32 	va_start(args, fmt);
33 
34 	vaf.fmt = fmt;
35 	vaf.va = &args;
36 
37 #ifdef __linux__
38 	if (is_error)
39 		dev_printk(level, kdev, "%pV", &vaf);
40 	else
41 		dev_printk(level, kdev, "[" DRM_NAME ":%ps] %pV",
42 			   __builtin_return_address(0), &vaf);
43 #else
44 	if (!is_error)
45 		printf("[" DRM_NAME "] ");
46 	vprintf(fmt, args);
47 #endif
48 
49 	va_end(args);
50 
51 	if (is_error && !shown_bug_once) {
52 		/*
53 		 * Ask the user to file a bug report for the error, except
54 		 * if they may have caused the bug by fiddling with unsafe
55 		 * module parameters.
56 		 */
57 #ifdef __linux__
58 		if (!test_taint(TAINT_USER))
59 			dev_notice(kdev, "%s", FDO_BUG_MSG);
60 #endif
61 		shown_bug_once = true;
62 	}
63 }
64 
add_taint_for_CI(struct drm_i915_private * i915,unsigned int taint)65 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
66 {
67 	__i915_printk(i915, KERN_NOTICE, "CI tainted:%#x by %pS\n",
68 		      taint, (void *)_RET_IP_);
69 
70 	/* Failures that occur during fault injection testing are expected */
71 	if (!i915_error_injected())
72 		__add_taint_for_CI(taint);
73 }
74 
75 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
76 static unsigned int i915_probe_fail_count;
77 
__i915_inject_probe_error(struct drm_i915_private * i915,int err,const char * func,int line)78 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
79 			      const char *func, int line)
80 {
81 	if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
82 		return 0;
83 
84 	if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
85 		return 0;
86 
87 	__i915_printk(i915, KERN_INFO,
88 		      "Injecting failure %d at checkpoint %u [%s:%d]\n",
89 		      err, i915_modparams.inject_probe_failure, func, line);
90 	i915_modparams.inject_probe_failure = 0;
91 	return err;
92 }
93 
i915_error_injected(void)94 bool i915_error_injected(void)
95 {
96 	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
97 }
98 
99 #endif
100 
cancel_timer(struct timeout * t)101 void cancel_timer(struct timeout *t)
102 {
103 	if (!timer_active(t))
104 		return;
105 
106 	del_timer(t);
107 	WRITE_ONCE(t->to_time, 0);
108 }
109 
set_timer_ms(struct timeout * t,unsigned long timeout)110 void set_timer_ms(struct timeout *t, unsigned long timeout)
111 {
112 	if (!timeout) {
113 		cancel_timer(t);
114 		return;
115 	}
116 
117 	timeout = msecs_to_jiffies(timeout);
118 
119 	/*
120 	 * Paranoia to make sure the compiler computes the timeout before
121 	 * loading 'jiffies' as jiffies is volatile and may be updated in
122 	 * the background by a timer tick. All to reduce the complexity
123 	 * of the addition and reduce the risk of losing a jiffie.
124 	 */
125 	barrier();
126 
127 	/* Keep t->expires = 0 reserved to indicate a canceled timer. */
128 	mod_timer(t, jiffies + timeout ?: 1);
129 }
130 
i915_vtd_active(struct drm_i915_private * i915)131 bool i915_vtd_active(struct drm_i915_private *i915)
132 {
133 	return false;
134 #ifdef notyet
135 	if (device_iommu_mapped(i915->drm.dev))
136 		return true;
137 
138 	/* Running as a guest, we assume the host is enforcing VT'd */
139 	return i915_run_as_guest();
140 #endif
141 }
142 
i915_direct_stolen_access(struct drm_i915_private * i915)143 bool i915_direct_stolen_access(struct drm_i915_private *i915)
144 {
145 	/*
146 	 * Wa_22018444074
147 	 *
148 	 * Access via BAR can hang MTL, go directly to GSM/DSM,
149 	 * except for VM guests which won't have access to it.
150 	 *
151 	 * Normally this would not work but on MTL the system firmware
152 	 * should have relaxed the access permissions sufficiently.
153 	 * 0x138914==0x1 indicates that the firmware has done its job.
154 	 */
155 	return IS_METEORLAKE(i915) && !i915_run_as_guest() &&
156 		intel_uncore_read(&i915->uncore, MTL_PCODE_STOLEN_ACCESS) == STOLEN_ACCESS_ALLOWED;
157 }
158