Quelle  intel_engine_user.c   Sprache: C

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2019 Intel Corporation
 */

#include <linux/list.h>
#include <linux/list_sort.h>
#include <linux/llist.h>

#include "i915_drv.h"
#include "intel_engine.h"
#include "intel_engine_user.h"
#include "intel_gt.h"
#include "uc/intel_guc_submission.h"

struct intel_engine_cs *
intel_engine_lookup_user(struct drm_i915_private *i915, u8 class, u8 instance)
{
 struct rb_node *p = i915->uabi_engines.rb_node;

 while (p) {
  struct intel_engine_cs *it =
   rb_entry(p, typeof(*it), uabi_node);

  if (class < it->uabi_class)
   p = p->rb_left;
  else if (class > it->uabi_class ||
    instance > it->uabi_instance)
   p = p->rb_right;
  else if (instance < it->uabi_instance)
   p = p->rb_left;
  else
   return it;
 }

 return NULL;
}

void intel_engine_add_user(struct intel_engine_cs *engine)
{
 llist_add(&engine->uabi_llist, &engine->i915->uabi_engines_llist);
}

#define I915_NO_UABI_CLASS ((u16)(-1))

static const u16 uabi_classes[] = {
 [RENDER_CLASS] = I915_ENGINE_CLASS_RENDER,
 [COPY_ENGINE_CLASS] = I915_ENGINE_CLASS_COPY,
 [VIDEO_DECODE_CLASS] = I915_ENGINE_CLASS_VIDEO,
 [VIDEO_ENHANCEMENT_CLASS] = I915_ENGINE_CLASS_VIDEO_ENHANCE,
 [COMPUTE_CLASS] = I915_ENGINE_CLASS_COMPUTE,
 [OTHER_CLASS] = I915_NO_UABI_CLASS, /* Not exposed to users, no uabi class. */
};

static int engine_cmp(void *priv, const struct list_head *A,
        const struct list_head *B)
{
 const struct intel_engine_cs *a =
  container_of(A, typeof(*a), uabi_list);
 const struct intel_engine_cs *b =
  container_of(B, typeof(*b), uabi_list);

 if (uabi_classes[a->class] < uabi_classes[b->class])
  return -1;
 if (uabi_classes[a->class] > uabi_classes[b->class])
  return 1;

 if (a->instance < b->instance)
  return -1;
 if (a->instance > b->instance)
  return 1;

 return 0;
}

static struct llist_node *get_engines(struct drm_i915_private *i915)
{
 return llist_del_all(&i915->uabi_engines_llist);
}

static void sort_engines(struct drm_i915_private *i915,
    struct list_head *engines)
{
 struct llist_node *pos, *next;

 llist_for_each_safe(pos, next, get_engines(i915)) {
  struct intel_engine_cs *engine =
   container_of(pos, typeof(*engine), uabi_llist);
  list_add(&engine->uabi_list, engines);
 }
 list_sort(NULL, engines, engine_cmp);
}

static void set_scheduler_caps(struct drm_i915_private *i915)
{
 static const struct {
  u8 engine;
  u8 sched;
 } map[] = {
#define MAP(x, y) { ilog2(I915_ENGINE_##x), ilog2(I915_SCHEDULER_CAP_##y) }
  MAP(HAS_PREEMPTION, PREEMPTION),
  MAP(HAS_SEMAPHORES, SEMAPHORES),
  MAP(SUPPORTS_STATS, ENGINE_BUSY_STATS),
#undef MAP
 };
 struct intel_engine_cs *engine;
 u32 enabled, disabled;

 enabled = 0;
 disabled = 0;
 for_each_uabi_engine(engine, i915) { /* all engines must agree! */
  int i;

  if (engine->sched_engine->schedule)
   enabled |= (I915_SCHEDULER_CAP_ENABLED |
        I915_SCHEDULER_CAP_PRIORITY);
  else
   disabled |= (I915_SCHEDULER_CAP_ENABLED |
         I915_SCHEDULER_CAP_PRIORITY);

  if (intel_uc_uses_guc_submission(&engine->gt->uc))
   enabled |= I915_SCHEDULER_CAP_STATIC_PRIORITY_MAP;

  for (i = 0; i < ARRAY_SIZE(map); i++) {
   if (engine->flags & BIT(map[i].engine))
    enabled |= BIT(map[i].sched);
   else
    disabled |= BIT(map[i].sched);
  }
 }

 i915->caps.scheduler = enabled & ~disabled;
 if (!(i915->caps.scheduler & I915_SCHEDULER_CAP_ENABLED))
  i915->caps.scheduler = 0;
}

const char *intel_engine_class_repr(u8 class)
{
 static const char * const uabi_names[] = {
  [RENDER_CLASS] = "rcs",
  [COPY_ENGINE_CLASS] = "bcs",
  [VIDEO_DECODE_CLASS] = "vcs",
  [VIDEO_ENHANCEMENT_CLASS] = "vecs",
  [OTHER_CLASS] = "other",
  [COMPUTE_CLASS] = "ccs",
 };

 if (class >= ARRAY_SIZE(uabi_names) || !uabi_names[class])
  return "xxx";

 return uabi_names[class];
}

struct legacy_ring {
 struct intel_gt *gt;
 u8 class;
 u8 instance;
};

static int legacy_ring_idx(const struct legacy_ring *ring)
{
 static const struct {
  u8 base, max;
 } map[] = {
  [RENDER_CLASS] = { RCS0, 1 },
  [COPY_ENGINE_CLASS] = { BCS0, 1 },
  [VIDEO_DECODE_CLASS] = { VCS0, I915_MAX_VCS },
  [VIDEO_ENHANCEMENT_CLASS] = { VECS0, I915_MAX_VECS },
  [COMPUTE_CLASS] = { CCS0, I915_MAX_CCS },
 };

 if (GEM_DEBUG_WARN_ON(ring->class >= ARRAY_SIZE(map)))
  return INVALID_ENGINE;

 if (GEM_DEBUG_WARN_ON(ring->instance >= map[ring->class].max))
  return INVALID_ENGINE;

 return map[ring->class].base + ring->instance;
}

static void add_legacy_ring(struct legacy_ring *ring,
       struct intel_engine_cs *engine)
{
 if (engine->gt != ring->gt || engine->class != ring->class) {
  ring->gt = engine->gt;
  ring->class = engine->class;
  ring->instance = 0;
 }

 engine->legacy_idx = legacy_ring_idx(ring);
 if (engine->legacy_idx != INVALID_ENGINE)
  ring->instance++;
}

static void engine_rename(struct intel_engine_cs *engine, const char *name, u16 instance)
{
 char old[sizeof(engine->name)];

 memcpy(old, engine->name, sizeof(engine->name));
 scnprintf(engine->name, sizeof(engine->name), "%s%u", name, instance);
 drm_dbg(&engine->i915->drm, "renamed %s to %s\n", old, engine->name);
}

void intel_engines_driver_register(struct drm_i915_private *i915)
{
 u16 name_instance, other_instance = 0;
 struct legacy_ring ring = {};
 struct list_head *it, *next;
 struct rb_node **p, *prev;
 LIST_HEAD(engines);

 sort_engines(i915, &engines);

 prev = NULL;
 p = &i915->uabi_engines.rb_node;
 list_for_each_safe(it, next, &engines) {
  struct intel_engine_cs *engine =
   container_of(it, typeof(*engine), uabi_list);

  if (intel_gt_has_unrecoverable_error(engine->gt))
   continue; /* ignore incomplete engines */

  GEM_BUG_ON(engine->class >= ARRAY_SIZE(uabi_classes));
  engine->uabi_class = uabi_classes[engine->class];
  if (engine->uabi_class == I915_NO_UABI_CLASS) {
   name_instance = other_instance++;
  } else {
   GEM_BUG_ON(engine->uabi_class >=
       ARRAY_SIZE(i915->engine_uabi_class_count));
   name_instance =
    i915->engine_uabi_class_count[engine->uabi_class]++;
  }
  engine->uabi_instance = name_instance;

  /*
 * Replace the internal name with the final user and log facing
 * name.
 */
  engine_rename(engine,
         intel_engine_class_repr(engine->class),
         name_instance);

  if (engine->uabi_class == I915_NO_UABI_CLASS)
   continue;

  rb_link_node(&engine->uabi_node, prev, p);
  rb_insert_color(&engine->uabi_node, &i915->uabi_engines);

  GEM_BUG_ON(intel_engine_lookup_user(i915,
          engine->uabi_class,
          engine->uabi_instance) != engine);

  /* Fix up the mapping to match default execbuf::user_map[] */
  add_legacy_ring(&ring, engine);

  prev = &engine->uabi_node;
  p = &prev->rb_right;
 }

 if (IS_ENABLED(CONFIG_DRM_I915_SELFTESTS) &&
     IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) {
  struct intel_engine_cs *engine;
  unsigned int isolation;
  int class, inst;
  int errors = 0;

  for (class = 0; class < ARRAY_SIZE(i915->engine_uabi_class_count); class++) {
   for (inst = 0; inst < i915->engine_uabi_class_count[class]; inst++) {
    engine = intel_engine_lookup_user(i915,
          class, inst);
    if (!engine) {
     pr_err("UABI engine not found for { class:%d, instance:%d }\n",
            class, inst);
     errors++;
     continue;
    }

    if (engine->uabi_class != class ||
        engine->uabi_instance != inst) {
     pr_err("Wrong UABI engine:%s { class:%d, instance:%d } found for { class:%d, instance:%d }\n",
            engine->name,
            engine->uabi_class,
            engine->uabi_instance,
            class, inst);
     errors++;
     continue;
    }
   }
  }

  /*
 * Make sure that classes with multiple engine instances all
 * share the same basic configuration.
 */
  isolation = intel_engines_has_context_isolation(i915);
  for_each_uabi_engine(engine, i915) {
   unsigned int bit = BIT(engine->uabi_class);
   unsigned int expected = engine->default_state ? bit : 0;

   if ((isolation & bit) != expected) {
    pr_err("mismatching default context state for class %d on engine %s\n",
           engine->uabi_class, engine->name);
    errors++;
   }
  }

  if (drm_WARN(&i915->drm, errors,
        "Invalid UABI engine mapping found"))
   i915->uabi_engines = RB_ROOT;
 }

 set_scheduler_caps(i915);
}

unsigned int intel_engines_has_context_isolation(struct drm_i915_private *i915)
{
 struct intel_engine_cs *engine;
 unsigned int which;

 which = 0;
 for_each_uabi_engine(engine, i915)
  if (engine->default_state)
   which |= BIT(engine->uabi_class);

 return which;
}