xref: /linux/drivers/gpu/drm/i915/i915_utils.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
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 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 
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 
43 bool i915_error_injected(void)
44 {
45 	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
46 }
47 
48 #endif
49 
50 bool i915_vtd_active(struct drm_i915_private *i915)
51 {
52 	if (device_iommu_mapped(i915->drm.dev))
53 		return true;
54 
55 	/* Running as a guest, we assume the host is enforcing VT'd */
56 	return i915_run_as_guest();
57 }
58 
59 bool i915_direct_stolen_access(struct drm_i915_private *i915)
60 {
61 	/*
62 	 * Wa_22018444074
63 	 *
64 	 * Access via BAR can hang MTL, go directly to GSM/DSM,
65 	 * except for VM guests which won't have access to it.
66 	 *
67 	 * Normally this would not work but on MTL the system firmware
68 	 * should have relaxed the access permissions sufficiently.
69 	 * 0x138914==0x1 indicates that the firmware has done its job.
70 	 */
71 	return IS_METEORLAKE(i915) && !i915_run_as_guest() &&
72 		intel_uncore_read(&i915->uncore, MTL_PCODE_STOLEN_ACCESS) == STOLEN_ACCESS_ALLOWED;
73 }
74