tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
14void 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)
25static unsigned int i915_probe_fail_count;
26
27int __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
43bool i915_error_injected(void)
44{
45 return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
46}
47
48#endif
49
50void 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
59void 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
80bool 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
89bool 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}