linux/drivers/gpu/drm/i915/gt/intel_engine_user.c
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   1/*
   2 * SPDX-License-Identifier: MIT
   3 *
   4 * Copyright © 2019 Intel Corporation
   5 */
   6
   7#include <linux/list.h>
   8#include <linux/list_sort.h>
   9#include <linux/llist.h>
  10
  11#include "i915_drv.h"
  12#include "intel_engine.h"
  13#include "intel_engine_user.h"
  14#include "intel_gt.h"
  15
  16struct intel_engine_cs *
  17intel_engine_lookup_user(struct drm_i915_private *i915, u8 class, u8 instance)
  18{
  19        struct rb_node *p = i915->uabi_engines.rb_node;
  20
  21        while (p) {
  22                struct intel_engine_cs *it =
  23                        rb_entry(p, typeof(*it), uabi_node);
  24
  25                if (class < it->uabi_class)
  26                        p = p->rb_left;
  27                else if (class > it->uabi_class ||
  28                         instance > it->uabi_instance)
  29                        p = p->rb_right;
  30                else if (instance < it->uabi_instance)
  31                        p = p->rb_left;
  32                else
  33                        return it;
  34        }
  35
  36        return NULL;
  37}
  38
  39void intel_engine_add_user(struct intel_engine_cs *engine)
  40{
  41        llist_add((struct llist_node *)&engine->uabi_node,
  42                  (struct llist_head *)&engine->i915->uabi_engines);
  43}
  44
  45static const u8 uabi_classes[] = {
  46        [RENDER_CLASS] = I915_ENGINE_CLASS_RENDER,
  47        [COPY_ENGINE_CLASS] = I915_ENGINE_CLASS_COPY,
  48        [VIDEO_DECODE_CLASS] = I915_ENGINE_CLASS_VIDEO,
  49        [VIDEO_ENHANCEMENT_CLASS] = I915_ENGINE_CLASS_VIDEO_ENHANCE,
  50};
  51
  52static int engine_cmp(void *priv, struct list_head *A, struct list_head *B)
  53{
  54        const struct intel_engine_cs *a =
  55                container_of((struct rb_node *)A, typeof(*a), uabi_node);
  56        const struct intel_engine_cs *b =
  57                container_of((struct rb_node *)B, typeof(*b), uabi_node);
  58
  59        if (uabi_classes[a->class] < uabi_classes[b->class])
  60                return -1;
  61        if (uabi_classes[a->class] > uabi_classes[b->class])
  62                return 1;
  63
  64        if (a->instance < b->instance)
  65                return -1;
  66        if (a->instance > b->instance)
  67                return 1;
  68
  69        return 0;
  70}
  71
  72static struct llist_node *get_engines(struct drm_i915_private *i915)
  73{
  74        return llist_del_all((struct llist_head *)&i915->uabi_engines);
  75}
  76
  77static void sort_engines(struct drm_i915_private *i915,
  78                         struct list_head *engines)
  79{
  80        struct llist_node *pos, *next;
  81
  82        llist_for_each_safe(pos, next, get_engines(i915)) {
  83                struct intel_engine_cs *engine =
  84                        container_of((struct rb_node *)pos, typeof(*engine),
  85                                     uabi_node);
  86                list_add((struct list_head *)&engine->uabi_node, engines);
  87        }
  88        list_sort(NULL, engines, engine_cmp);
  89}
  90
  91static void set_scheduler_caps(struct drm_i915_private *i915)
  92{
  93        static const struct {
  94                u8 engine;
  95                u8 sched;
  96        } map[] = {
  97#define MAP(x, y) { ilog2(I915_ENGINE_##x), ilog2(I915_SCHEDULER_CAP_##y) }
  98                MAP(HAS_PREEMPTION, PREEMPTION),
  99                MAP(HAS_SEMAPHORES, SEMAPHORES),
 100                MAP(SUPPORTS_STATS, ENGINE_BUSY_STATS),
 101#undef MAP
 102        };
 103        struct intel_engine_cs *engine;
 104        u32 enabled, disabled;
 105
 106        enabled = 0;
 107        disabled = 0;
 108        for_each_uabi_engine(engine, i915) { /* all engines must agree! */
 109                int i;
 110
 111                if (engine->schedule)
 112                        enabled |= (I915_SCHEDULER_CAP_ENABLED |
 113                                    I915_SCHEDULER_CAP_PRIORITY);
 114                else
 115                        disabled |= (I915_SCHEDULER_CAP_ENABLED |
 116                                     I915_SCHEDULER_CAP_PRIORITY);
 117
 118                for (i = 0; i < ARRAY_SIZE(map); i++) {
 119                        if (engine->flags & BIT(map[i].engine))
 120                                enabled |= BIT(map[i].sched);
 121                        else
 122                                disabled |= BIT(map[i].sched);
 123                }
 124        }
 125
 126        i915->caps.scheduler = enabled & ~disabled;
 127        if (!(i915->caps.scheduler & I915_SCHEDULER_CAP_ENABLED))
 128                i915->caps.scheduler = 0;
 129}
 130
 131const char *intel_engine_class_repr(u8 class)
 132{
 133        static const char * const uabi_names[] = {
 134                [RENDER_CLASS] = "rcs",
 135                [COPY_ENGINE_CLASS] = "bcs",
 136                [VIDEO_DECODE_CLASS] = "vcs",
 137                [VIDEO_ENHANCEMENT_CLASS] = "vecs",
 138        };
 139
 140        if (class >= ARRAY_SIZE(uabi_names) || !uabi_names[class])
 141                return "xxx";
 142
 143        return uabi_names[class];
 144}
 145
 146struct legacy_ring {
 147        struct intel_gt *gt;
 148        u8 class;
 149        u8 instance;
 150};
 151
 152static int legacy_ring_idx(const struct legacy_ring *ring)
 153{
 154        static const struct {
 155                u8 base, max;
 156        } map[] = {
 157                [RENDER_CLASS] = { RCS0, 1 },
 158                [COPY_ENGINE_CLASS] = { BCS0, 1 },
 159                [VIDEO_DECODE_CLASS] = { VCS0, I915_MAX_VCS },
 160                [VIDEO_ENHANCEMENT_CLASS] = { VECS0, I915_MAX_VECS },
 161        };
 162
 163        if (GEM_DEBUG_WARN_ON(ring->class >= ARRAY_SIZE(map)))
 164                return INVALID_ENGINE;
 165
 166        if (GEM_DEBUG_WARN_ON(ring->instance >= map[ring->class].max))
 167                return INVALID_ENGINE;
 168
 169        return map[ring->class].base + ring->instance;
 170}
 171
 172static void add_legacy_ring(struct legacy_ring *ring,
 173                            struct intel_engine_cs *engine)
 174{
 175        if (engine->gt != ring->gt || engine->class != ring->class) {
 176                ring->gt = engine->gt;
 177                ring->class = engine->class;
 178                ring->instance = 0;
 179        }
 180
 181        engine->legacy_idx = legacy_ring_idx(ring);
 182        if (engine->legacy_idx != INVALID_ENGINE)
 183                ring->instance++;
 184}
 185
 186void intel_engines_driver_register(struct drm_i915_private *i915)
 187{
 188        struct legacy_ring ring = {};
 189        u8 uabi_instances[4] = {};
 190        struct list_head *it, *next;
 191        struct rb_node **p, *prev;
 192        LIST_HEAD(engines);
 193
 194        sort_engines(i915, &engines);
 195
 196        prev = NULL;
 197        p = &i915->uabi_engines.rb_node;
 198        list_for_each_safe(it, next, &engines) {
 199                struct intel_engine_cs *engine =
 200                        container_of((struct rb_node *)it, typeof(*engine),
 201                                     uabi_node);
 202                char old[sizeof(engine->name)];
 203
 204                if (intel_gt_has_unrecoverable_error(engine->gt))
 205                        continue; /* ignore incomplete engines */
 206
 207                GEM_BUG_ON(engine->class >= ARRAY_SIZE(uabi_classes));
 208                engine->uabi_class = uabi_classes[engine->class];
 209
 210                GEM_BUG_ON(engine->uabi_class >= ARRAY_SIZE(uabi_instances));
 211                engine->uabi_instance = uabi_instances[engine->uabi_class]++;
 212
 213                /* Replace the internal name with the final user facing name */
 214                memcpy(old, engine->name, sizeof(engine->name));
 215                scnprintf(engine->name, sizeof(engine->name), "%s%u",
 216                          intel_engine_class_repr(engine->class),
 217                          engine->uabi_instance);
 218                DRM_DEBUG_DRIVER("renamed %s to %s\n", old, engine->name);
 219
 220                rb_link_node(&engine->uabi_node, prev, p);
 221                rb_insert_color(&engine->uabi_node, &i915->uabi_engines);
 222
 223                GEM_BUG_ON(intel_engine_lookup_user(i915,
 224                                                    engine->uabi_class,
 225                                                    engine->uabi_instance) != engine);
 226
 227                /* Fix up the mapping to match default execbuf::user_map[] */
 228                add_legacy_ring(&ring, engine);
 229
 230                prev = &engine->uabi_node;
 231                p = &prev->rb_right;
 232        }
 233
 234        if (IS_ENABLED(CONFIG_DRM_I915_SELFTESTS) &&
 235            IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) {
 236                struct intel_engine_cs *engine;
 237                unsigned int isolation;
 238                int class, inst;
 239                int errors = 0;
 240
 241                for (class = 0; class < ARRAY_SIZE(uabi_instances); class++) {
 242                        for (inst = 0; inst < uabi_instances[class]; inst++) {
 243                                engine = intel_engine_lookup_user(i915,
 244                                                                  class, inst);
 245                                if (!engine) {
 246                                        pr_err("UABI engine not found for { class:%d, instance:%d }\n",
 247                                               class, inst);
 248                                        errors++;
 249                                        continue;
 250                                }
 251
 252                                if (engine->uabi_class != class ||
 253                                    engine->uabi_instance != inst) {
 254                                        pr_err("Wrong UABI engine:%s { class:%d, instance:%d } found for { class:%d, instance:%d }\n",
 255                                               engine->name,
 256                                               engine->uabi_class,
 257                                               engine->uabi_instance,
 258                                               class, inst);
 259                                        errors++;
 260                                        continue;
 261                                }
 262                        }
 263                }
 264
 265                /*
 266                 * Make sure that classes with multiple engine instances all
 267                 * share the same basic configuration.
 268                 */
 269                isolation = intel_engines_has_context_isolation(i915);
 270                for_each_uabi_engine(engine, i915) {
 271                        unsigned int bit = BIT(engine->uabi_class);
 272                        unsigned int expected = engine->default_state ? bit : 0;
 273
 274                        if ((isolation & bit) != expected) {
 275                                pr_err("mismatching default context state for class %d on engine %s\n",
 276                                       engine->uabi_class, engine->name);
 277                                errors++;
 278                        }
 279                }
 280
 281                if (drm_WARN(&i915->drm, errors,
 282                             "Invalid UABI engine mapping found"))
 283                        i915->uabi_engines = RB_ROOT;
 284        }
 285
 286        set_scheduler_caps(i915);
 287}
 288
 289unsigned int intel_engines_has_context_isolation(struct drm_i915_private *i915)
 290{
 291        struct intel_engine_cs *engine;
 292        unsigned int which;
 293
 294        which = 0;
 295        for_each_uabi_engine(engine, i915)
 296                if (engine->default_state)
 297                        which |= BIT(engine->uabi_class);
 298
 299        return which;
 300}
 301