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  
add_taint_for_CI(struct drm_i915_private * i915,unsigned int taint)14  void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
15  {
16  	drm_notice(&i915->drm, "CI tainted: %#x by %pS\n",
17  		   taint, __builtin_return_address(0));
18  
19  	/* Failures that occur during fault injection testing are expected */
20  	if (!i915_error_injected())
21  		__add_taint_for_CI(taint);
22  }
23  
24  #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
25  static unsigned int i915_probe_fail_count;
26  
__i915_inject_probe_error(struct drm_i915_private * i915,int err,const char * func,int line)27  int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
28  			      const char *func, int line)
29  {
30  	if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
31  		return 0;
32  
33  	if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
34  		return 0;
35  
36  	drm_info(&i915->drm, "Injecting failure %d at checkpoint %u [%s:%d]\n",
37  		 err, i915_modparams.inject_probe_failure, func, line);
38  
39  	i915_modparams.inject_probe_failure = 0;
40  	return err;
41  }
42  
i915_error_injected(void)43  bool i915_error_injected(void)
44  {
45  	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
46  }
47  
48  #endif
49  
cancel_timer(struct timer_list * t)50  void cancel_timer(struct timer_list *t)
51  {
52  	if (!timer_active(t))
53  		return;
54  
55  	del_timer(t);
56  	WRITE_ONCE(t->expires, 0);
57  }
58  
set_timer_ms(struct timer_list * t,unsigned long timeout)59  void set_timer_ms(struct timer_list *t, unsigned long timeout)
60  {
61  	if (!timeout) {
62  		cancel_timer(t);
63  		return;
64  	}
65  
66  	timeout = msecs_to_jiffies(timeout);
67  
68  	/*
69  	 * Paranoia to make sure the compiler computes the timeout before
70  	 * loading 'jiffies' as jiffies is volatile and may be updated in
71  	 * the background by a timer tick. All to reduce the complexity
72  	 * of the addition and reduce the risk of losing a jiffy.
73  	 */
74  	barrier();
75  
76  	/* Keep t->expires = 0 reserved to indicate a canceled timer. */
77  	mod_timer(t, jiffies + timeout ?: 1);
78  }
79  
i915_vtd_active(struct drm_i915_private * i915)80  bool i915_vtd_active(struct drm_i915_private *i915)
81  {
82  	if (device_iommu_mapped(i915->drm.dev))
83  		return true;
84  
85  	/* Running as a guest, we assume the host is enforcing VT'd */
86  	return i915_run_as_guest();
87  }
88  
i915_direct_stolen_access(struct drm_i915_private * i915)89  bool i915_direct_stolen_access(struct drm_i915_private *i915)
90  {
91  	/*
92  	 * Wa_22018444074
93  	 *
94  	 * Access via BAR can hang MTL, go directly to GSM/DSM,
95  	 * except for VM guests which won't have access to it.
96  	 *
97  	 * Normally this would not work but on MTL the system firmware
98  	 * should have relaxed the access permissions sufficiently.
99  	 * 0x138914==0x1 indicates that the firmware has done its job.
100  	 */
101  	return IS_METEORLAKE(i915) && !i915_run_as_guest() &&
102  		intel_uncore_read(&i915->uncore, MTL_PCODE_STOLEN_ACCESS) == STOLEN_ACCESS_ALLOWED;
103  }
104