drivers/gpu/drm/i915/gt/intel_engine_user.c

   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
  15 struct intel_engine_cs *
  16 intel_engine_lookup_user(struct drm_i915_private *i915, u8 class, u8 instance)
  17 {
  18         struct rb_node *p = i915->uabi_engines.rb_node;
  19
  20         while (p) {
  21                 struct intel_engine_cs *it =
  22                         rb_entry(p, typeof(*it), uabi_node);
  23
  24                 if (class < it->uabi_class)
  25                         p = p->rb_left;
  26                 else if (class > it->uabi_class ||
  27                          instance > it->uabi_instance)
  28                         p = p->rb_right;
  29                 else if (instance < it->uabi_instance)
  30                         p = p->rb_left;
  31                 else
  32                         return it;
  33         }
  34
  35         return NULL;
  36 }
  37
  38 void intel_engine_add_user(struct intel_engine_cs *engine)
  39 {
  40         llist_add((struct llist_node *)&engine->uabi_node,
  41                   (struct llist_head *)&engine->i915->uabi_engines);
  42 }
  43
  44 static const u8 uabi_classes[] = {
  45         [RENDER_CLASS] = I915_ENGINE_CLASS_RENDER,
  46         [COPY_ENGINE_CLASS] = I915_ENGINE_CLASS_COPY,
  47         [VIDEO_DECODE_CLASS] = I915_ENGINE_CLASS_VIDEO,
  48         [VIDEO_ENHANCEMENT_CLASS] = I915_ENGINE_CLASS_VIDEO_ENHANCE,
  49 };
  50
  51 static int engine_cmp(void *priv, struct list_head *A, struct list_head *B)
  52 {
  53         const struct intel_engine_cs *a =
  54                 container_of((struct rb_node *)A, typeof(*a), uabi_node);
  55         const struct intel_engine_cs *b =
  56                 container_of((struct rb_node *)B, typeof(*b), uabi_node);
  57
  58         if (uabi_classes[a->class] < uabi_classes[b->class])
  59                 return -1;
  60         if (uabi_classes[a->class] > uabi_classes[b->class])
  61                 return 1;
  62
  63         if (a->instance < b->instance)
  64                 return -1;
  65         if (a->instance > b->instance)
  66                 return 1;
  67
  68         return 0;
  69 }
  70
  71 static struct llist_node *get_engines(struct drm_i915_private *i915)
  72 {
  73         return llist_del_all((struct llist_head *)&i915->uabi_engines);
  74 }
  75
  76 static void sort_engines(struct drm_i915_private *i915,
  77                          struct list_head *engines)
  78 {
  79         struct llist_node *pos, *next;
  80
  81         llist_for_each_safe(pos, next, get_engines(i915)) {
  82                 struct intel_engine_cs *engine =
  83                         container_of((struct rb_node *)pos, typeof(*engine),
  84                                      uabi_node);
  85                 list_add((struct list_head *)&engine->uabi_node, engines);
  86         }
  87         list_sort(NULL, engines, engine_cmp);
  88 }
  89
  90 static void set_scheduler_caps(struct drm_i915_private *i915)
  91 {
  92         static const struct {
  93                 u8 engine;
  94                 u8 sched;
  95         } map[] = {
  96 #define MAP(x, y) { ilog2(I915_ENGINE_##x), ilog2(I915_SCHEDULER_CAP_##y) }
  97                 MAP(HAS_PREEMPTION, PREEMPTION),
  98                 MAP(HAS_SEMAPHORES, SEMAPHORES),
  99                 MAP(SUPPORTS_STATS, ENGINE_BUSY_STATS),
 100 #undef MAP
 101         };
 102         struct intel_engine_cs *engine;
 103         u32 enabled, disabled;
 104
 105         enabled = 0;
 106         disabled = 0;
 107         for_each_uabi_engine(engine, i915) { /* all engines must agree! */
 108                 int i;
 109
 110                 if (engine->schedule)
 111                         enabled |= (I915_SCHEDULER_CAP_ENABLED |
 112                                     I915_SCHEDULER_CAP_PRIORITY);
 113                 else
 114                         disabled |= (I915_SCHEDULER_CAP_ENABLED |
 115                                      I915_SCHEDULER_CAP_PRIORITY);
 116
 117                 for (i = 0; i < ARRAY_SIZE(map); i++) {
 118                         if (engine->flags & BIT(map[i].engine))
 119                                 enabled |= BIT(map[i].sched);
 120                         else
 121                                 disabled |= BIT(map[i].sched);
 122                 }
 123         }
 124
 125         i915->caps.scheduler = enabled & ~disabled;
 126         if (!(i915->caps.scheduler & I915_SCHEDULER_CAP_ENABLED))
 127                 i915->caps.scheduler = 0;
 128 }
 129
 130 const char *intel_engine_class_repr(u8 class)
 131 {
 132         static const char * const uabi_names[] = {
 133                 [RENDER_CLASS] = "rcs",
 134                 [COPY_ENGINE_CLASS] = "bcs",
 135                 [VIDEO_DECODE_CLASS] = "vcs",
 136                 [VIDEO_ENHANCEMENT_CLASS] = "vecs",
 137         };
 138
 139         if (class >= ARRAY_SIZE(uabi_names) || !uabi_names[class])
 140                 return "xxx";
 141
 142         return uabi_names[class];
 143 }
 144
 145 struct legacy_ring {
 146         struct intel_gt *gt;
 147         u8 class;
 148         u8 instance;
 149 };
 150
 151 static int legacy_ring_idx(const struct legacy_ring *ring)
 152 {
 153         static const struct {
 154                 u8 base, max;
 155         } map[] = {
 156                 [RENDER_CLASS] = { RCS0, 1 },
 157                 [COPY_ENGINE_CLASS] = { BCS0, 1 },
 158                 [VIDEO_DECODE_CLASS] = { VCS0, I915_MAX_VCS },
 159                 [VIDEO_ENHANCEMENT_CLASS] = { VECS0, I915_MAX_VECS },
 160         };
 161
 162         if (GEM_DEBUG_WARN_ON(ring->class >= ARRAY_SIZE(map)))
 163                 return -1;
 164
 165         if (GEM_DEBUG_WARN_ON(ring->instance >= map[ring->class].max))
 166                 return -1;
 167
 168         return map[ring->class].base + ring->instance;
 169 }
 170
 171 static void add_legacy_ring(struct legacy_ring *ring,
 172                             struct intel_engine_cs *engine)
 173 {
 174         int idx;
 175
 176         if (engine->gt != ring->gt || engine->class != ring->class) {
 177                 ring->gt = engine->gt;
 178                 ring->class = engine->class;
 179                 ring->instance = 0;
 180         }
 181
 182         idx = legacy_ring_idx(ring);
 183         if (unlikely(idx == -1))
 184                 return;
 185
 186         GEM_BUG_ON(idx >= ARRAY_SIZE(ring->gt->engine));
 187         ring->gt->engine[idx] = engine;
 188         ring->instance++;
 189
 190         engine->legacy_idx = idx;
 191 }
 192
 193 void intel_engines_driver_register(struct drm_i915_private *i915)
 194 {
 195         struct legacy_ring ring = {};
 196         u8 uabi_instances[4] = {};
 197         struct list_head *it, *next;
 198         struct rb_node **p, *prev;
 199         LIST_HEAD(engines);
 200
 201         sort_engines(i915, &engines);
 202
 203         prev = NULL;
 204         p = &i915->uabi_engines.rb_node;
 205         list_for_each_safe(it, next, &engines) {
 206                 struct intel_engine_cs *engine =
 207                         container_of((struct rb_node *)it, typeof(*engine),
 208                                      uabi_node);
 209                 char old[sizeof(engine->name)];
 210
 211                 GEM_BUG_ON(engine->class >= ARRAY_SIZE(uabi_classes));
 212                 engine->uabi_class = uabi_classes[engine->class];
 213
 214                 GEM_BUG_ON(engine->uabi_class >= ARRAY_SIZE(uabi_instances));
 215                 engine->uabi_instance = uabi_instances[engine->uabi_class]++;
 216
 217                 /* Replace the internal name with the final user facing name */
 218                 memcpy(old, engine->name, sizeof(engine->name));
 219                 scnprintf(engine->name, sizeof(engine->name), "%s%u",
 220                           intel_engine_class_repr(engine->class),
 221                           engine->uabi_instance);
 222                 DRM_DEBUG_DRIVER("renamed %s to %s\n", old, engine->name);
 223
 224                 rb_link_node(&engine->uabi_node, prev, p);
 225                 rb_insert_color(&engine->uabi_node, &i915->uabi_engines);
 226
 227                 GEM_BUG_ON(intel_engine_lookup_user(i915,
 228                                                     engine->uabi_class,
 229                                                     engine->uabi_instance) != engine);
 230
 231                 /* Fix up the mapping to match default execbuf::user_map[] */
 232                 add_legacy_ring(&ring, engine);
 233
 234                 prev = &engine->uabi_node;
 235                 p = &prev->rb_right;
 236         }
 237
 238         if (IS_ENABLED(CONFIG_DRM_I915_SELFTESTS) &&
 239             IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) {
 240                 struct intel_engine_cs *engine;
 241                 unsigned int isolation;
 242                 int class, inst;
 243                 int errors = 0;
 244
 245                 for (class = 0; class < ARRAY_SIZE(uabi_instances); class++) {
 246                         for (inst = 0; inst < uabi_instances[class]; inst++) {
 247                                 engine = intel_engine_lookup_user(i915,
 248                                                                   class, inst);
 249                                 if (!engine) {
 250                                         pr_err("UABI engine not found for { class:%d, instance:%d }\n",
 251                                                class, inst);
 252                                         errors++;
 253                                         continue;
 254                                 }
 255
 256                                 if (engine->uabi_class != class ||
 257                                     engine->uabi_instance != inst) {
 258                                         pr_err("Wrong UABI engine:%s { class:%d, instance:%d } found for { class:%d, instance:%d }\n",
 259                                                engine->name,
 260                                                engine->uabi_class,
 261                                                engine->uabi_instance,
 262                                                class, inst);
 263                                         errors++;
 264                                         continue;
 265                                 }
 266                         }
 267                 }
 268
 269                 /*
 270                  * Make sure that classes with multiple engine instances all
 271                  * share the same basic configuration.
 272                  */
 273                 isolation = intel_engines_has_context_isolation(i915);
 274                 for_each_uabi_engine(engine, i915) {
 275                         unsigned int bit = BIT(engine->uabi_class);
 276                         unsigned int expected = engine->default_state ? bit : 0;
 277
 278                         if ((isolation & bit) != expected) {
 279                                 pr_err("mismatching default context state for class %d on engine %s\n",
 280                                        engine->uabi_class, engine->name);
 281                                 errors++;
 282                         }
 283                 }
 284
 285                 if (WARN(errors, "Invalid UABI engine mapping found"))
 286                         i915->uabi_engines = RB_ROOT;
 287         }
 288
 289         set_scheduler_caps(i915);
 290 }
 291
 292 unsigned int intel_engines_has_context_isolation(struct drm_i915_private *i915)
 293 {
 294         struct intel_engine_cs *engine;
 295         unsigned int which;
 296
 297         which = 0;
 298         for_each_uabi_engine(engine, i915)
 299                 if (engine->default_state)
 300                         which |= BIT(engine->uabi_class);
 301
 302         return which;
 303 }