1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright © 2023 Intel Corporation
4 */
5
6#ifndef _XE_ASSERT_H_
7#define _XE_ASSERT_H_
8
9#include <linux/string_helpers.h>
10
11#include <drm/drm_print.h>
12
13#include "xe_gt_types.h"
14#include "xe_step.h"
15#include "xe_vram.h"
16
17/**
18 * DOC: Xe Asserts
19 *
20 * While Xe driver aims to be simpler than legacy i915 driver it is still
21 * complex enough that some changes introduced while adding new functionality
22 * could break the existing code.
23 *
24 * Adding &drm_WARN or &drm_err to catch unwanted programming usage could lead
25 * to undesired increased driver footprint and may impact production driver
26 * performance as this additional code will be always present.
27 *
28 * To allow annotate functions with additional detailed debug checks to assert
29 * that all prerequisites are satisfied, without worrying about footprint or
30 * performance penalty on production builds where all potential misuses
31 * introduced during code integration were already fixed, we introduce family
32 * of Xe assert macros that try to follow classic assert() utility:
33 *
34 * * xe_assert()
35 * * xe_tile_assert()
36 * * xe_gt_assert()
37 *
38 * These macros are implemented on top of &drm_WARN, but unlikely to the origin,
39 * warning is triggered when provided condition is false. Additionally all above
40 * assert macros cannot be used in expressions or as a condition, since
41 * underlying code will be compiled out on non-debug builds.
42 *
43 * Note that these macros are not intended for use to cover known gaps in the
44 * implementation; for such cases use regular &drm_WARN or &drm_err and provide
45 * valid safe fallback.
46 *
47 * Also in cases where performance or footprint is not an issue, developers
48 * should continue to use the regular &drm_WARN or &drm_err to ensure that bug
49 * reports from production builds will contain meaningful diagnostics data.
50 *
51 * Below code shows how asserts could help in debug to catch unplanned use::
52 *
53 * static void one_igfx(struct xe_device *xe)
54 * {
55 * xe_assert(xe, xe->info.is_dgfx == false);
56 * xe_assert(xe, xe->info.tile_count == 1);
57 * }
58 *
59 * static void two_dgfx(struct xe_device *xe)
60 * {
61 * xe_assert(xe, xe->info.is_dgfx);
62 * xe_assert(xe, xe->info.tile_count == 2);
63 * }
64 *
65 * void foo(struct xe_device *xe)
66 * {
67 * if (xe->info.dgfx)
68 * return two_dgfx(xe);
69 * return one_igfx(xe);
70 * }
71 *
72 * void bar(struct xe_device *xe)
73 * {
74 * if (drm_WARN_ON(xe->drm, xe->info.tile_count > 2))
75 * return;
76 *
77 * if (xe->info.tile_count == 2)
78 * return two_dgfx(xe);
79 * return one_igfx(xe);
80 * }
81 */
82
83#if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
84#define __xe_assert_msg(xe, condition, msg, arg...) ({ \
85 (void)drm_WARN(&(xe)->drm, !(condition), "Assertion `%s` failed!\n" msg, \
86 __stringify(condition), ## arg); \
87})
88#else
89#define __xe_assert_msg(xe, condition, msg, arg...) ({ \
90 typecheck(const struct xe_device *, xe); \
91 BUILD_BUG_ON_INVALID(condition); \
92})
93#endif
94
95/**
96 * xe_assert - warn if condition is false when debugging.
97 * @xe: the &struct xe_device pointer to which &condition applies
98 * @condition: condition to check
99 *
100 * xe_assert() uses &drm_WARN to emit a warning and print additional information
101 * that could be read from the &xe pointer if provided &condition is false.
102 *
103 * Contrary to &drm_WARN, xe_assert() is effective only on debug builds
104 * (&CONFIG_DRM_XE_DEBUG must be enabled) and cannot be used in expressions
105 * or as a condition.
106 *
107 * See `Xe Asserts`_ for general usage guidelines.
108 */
109#define xe_assert(xe, condition) xe_assert_msg((xe), condition, "")
110#define xe_assert_msg(xe, condition, msg, arg...) ({ \
111 const struct xe_device *__xe = (xe); \
112 __xe_assert_msg(__xe, condition, \
113 "platform: %s subplatform: %d\n" \
114 "graphics: %s %u.%02u step %s\n" \
115 "media: %s %u.%02u step %s\n" \
116 msg, \
117 __xe->info.platform_name, __xe->info.subplatform, \
118 __xe->info.graphics_name, \
119 __xe->info.graphics_verx100 / 100, \
120 __xe->info.graphics_verx100 % 100, \
121 xe_step_name(__xe->info.step.graphics), \
122 __xe->info.media_name, \
123 __xe->info.media_verx100 / 100, \
124 __xe->info.media_verx100 % 100, \
125 xe_step_name(__xe->info.step.media), \
126 ## arg); \
127})
128
129/**
130 * xe_tile_assert - warn if condition is false when debugging.
131 * @tile: the &struct xe_tile pointer to which &condition applies
132 * @condition: condition to check
133 *
134 * xe_tile_assert() uses &drm_WARN to emit a warning and print additional
135 * information that could be read from the &tile pointer if provided &condition
136 * is false.
137 *
138 * Contrary to &drm_WARN, xe_tile_assert() is effective only on debug builds
139 * (&CONFIG_DRM_XE_DEBUG must be enabled) and cannot be used in expressions
140 * or as a condition.
141 *
142 * See `Xe Asserts`_ for general usage guidelines.
143 */
144#define xe_tile_assert(tile, condition) xe_tile_assert_msg((tile), condition, "")
145#define xe_tile_assert_msg(tile, condition, msg, arg...) ({ \
146 const struct xe_tile *__tile = (tile); \
147 char __buf[10] __maybe_unused; \
148 xe_assert_msg(tile_to_xe(__tile), condition, "tile: %u VRAM %s\n" msg, \
149 __tile->id, ({ string_get_size( \
150 xe_vram_region_actual_physical_size(__tile->mem.vram), 1, \
151 STRING_UNITS_2, __buf, sizeof(__buf)); __buf; }), ## arg); \
152})
153
154/**
155 * xe_gt_assert - warn if condition is false when debugging.
156 * @gt: the &struct xe_gt pointer to which &condition applies
157 * @condition: condition to check
158 *
159 * xe_gt_assert() uses &drm_WARN to emit a warning and print additional
160 * information that could be safetely read from the &gt pointer if provided
161 * &condition is false.
162 *
163 * Contrary to &drm_WARN, xe_gt_assert() is effective only on debug builds
164 * (&CONFIG_DRM_XE_DEBUG must be enabled) and cannot be used in expressions
165 * or as a condition.
166 *
167 * See `Xe Asserts`_ for general usage guidelines.
168 */
169#define xe_gt_assert(gt, condition) xe_gt_assert_msg((gt), condition, "")
170#define xe_gt_assert_msg(gt, condition, msg, arg...) ({ \
171 const struct xe_gt *__gt = (gt); \
172 xe_tile_assert_msg(gt_to_tile(__gt), condition, "GT: %u type %d\n" msg, \
173 __gt->info.id, __gt->info.type, ## arg); \
174})
175
176#endif
177

source code of linux/drivers/gpu/drm/xe/xe_assert.h