xe_assert.h

  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