xref: /linux/drivers/gpu/drm/i915/i915_utils.c (revision f6e8dc9edf963dbc99085e54f6ced6da9daa6100)
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 #include <drm/drm_print.h>
10 
11 #include "i915_drv.h"
12 #include "i915_reg.h"
13 #include "i915_utils.h"
14 
15 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
16 {
17 	drm_notice(&i915->drm, "CI tainted: %#x by %pS\n",
18 		   taint, __builtin_return_address(0));
19 
20 	/* Failures that occur during fault injection testing are expected */
21 	if (!i915_error_injected())
22 		__add_taint_for_CI(taint);
23 }
24 
25 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
26 static unsigned int i915_probe_fail_count;
27 
28 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
29 			      const char *func, int line)
30 {
31 	if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
32 		return 0;
33 
34 	if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
35 		return 0;
36 
37 	drm_info(&i915->drm, "Injecting failure %d at checkpoint %u [%s:%d]\n",
38 		 err, i915_modparams.inject_probe_failure, func, line);
39 
40 	i915_modparams.inject_probe_failure = 0;
41 	return err;
42 }
43 
44 bool i915_error_injected(void)
45 {
46 	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
47 }
48 
49 #endif
50 
51 bool i915_vtd_active(struct drm_i915_private *i915)
52 {
53 	if (device_iommu_mapped(i915->drm.dev))
54 		return true;
55 
56 	/* Running as a guest, we assume the host is enforcing VT'd */
57 	return i915_run_as_guest();
58 }
59 
60 bool i915_direct_stolen_access(struct drm_i915_private *i915)
61 {
62 	/*
63 	 * Wa_22018444074
64 	 *
65 	 * Access via BAR can hang MTL, go directly to GSM/DSM,
66 	 * except for VM guests which won't have access to it.
67 	 *
68 	 * Normally this would not work but on MTL the system firmware
69 	 * should have relaxed the access permissions sufficiently.
70 	 * 0x138914==0x1 indicates that the firmware has done its job.
71 	 */
72 	return IS_METEORLAKE(i915) && !i915_run_as_guest() &&
73 		intel_uncore_read(&i915->uncore, MTL_PCODE_STOLEN_ACCESS) == STOLEN_ACCESS_ALLOWED;
74 }
75