Quelle  intel_global_state.c   Sprache: C

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2020 Intel Corporation
 */

#include <linux/pci.h>
#include <linux/string.h>

#include <drm/drm_print.h>

#include "intel_atomic.h"
#include "intel_display_core.h"
#include "intel_display_types.h"
#include "intel_global_state.h"

struct intel_global_commit {
 struct kref ref;
 struct completion done;
};

static struct intel_global_commit *commit_new(void)
{
 struct intel_global_commit *commit;

 commit = kzalloc(sizeof(*commit), GFP_KERNEL);
 if (!commit)
  return NULL;

 init_completion(&commit->done);
 kref_init(&commit->ref);

 return commit;
}

static void __commit_free(struct kref *kref)
{
 struct intel_global_commit *commit =
  container_of(kref, typeof(*commit), ref);

 kfree(commit);
}

static struct intel_global_commit *commit_get(struct intel_global_commit *commit)
{
 if (commit)
  kref_get(&commit->ref);

 return commit;
}

static void commit_put(struct intel_global_commit *commit)
{
 if (commit)
  kref_put(&commit->ref, __commit_free);
}

static void __intel_atomic_global_state_free(struct kref *kref)
{
 struct intel_global_state *obj_state =
  container_of(kref, struct intel_global_state, ref);
 struct intel_global_obj *obj = obj_state->obj;

 commit_put(obj_state->commit);

 obj->funcs->atomic_destroy_state(obj, obj_state);
}

static void intel_atomic_global_state_put(struct intel_global_state *obj_state)
{
 kref_put(&obj_state->ref, __intel_atomic_global_state_free);
}

static struct intel_global_state *
intel_atomic_global_state_get(struct intel_global_state *obj_state)
{
 kref_get(&obj_state->ref);

 return obj_state;
}

void intel_atomic_global_obj_init(struct intel_display *display,
      struct intel_global_obj *obj,
      struct intel_global_state *state,
      const struct intel_global_state_funcs *funcs)
{
 memset(obj, 0, sizeof(*obj));

 state->obj = obj;

 kref_init(&state->ref);

 obj->state = state;
 obj->funcs = funcs;
 list_add_tail(&obj->head, &display->global.obj_list);
}

void intel_atomic_global_obj_cleanup(struct intel_display *display)
{
 struct intel_global_obj *obj, *next;

 list_for_each_entry_safe(obj, next, &display->global.obj_list, head) {
  list_del(&obj->head);

  drm_WARN_ON(display->drm, kref_read(&obj->state->ref) != 1);
  intel_atomic_global_state_put(obj->state);
 }
}

static void assert_global_state_write_locked(struct intel_display *display)
{
 struct intel_crtc *crtc;

 for_each_intel_crtc(display->drm, crtc)
  drm_modeset_lock_assert_held(&crtc->base.mutex);
}

static bool modeset_lock_is_held(struct drm_modeset_acquire_ctx *ctx,
     struct drm_modeset_lock *lock)
{
 struct drm_modeset_lock *l;

 list_for_each_entry(l, &ctx->locked, head) {
  if (lock == l)
   return true;
 }

 return false;
}

static void assert_global_state_read_locked(struct intel_atomic_state *state)
{
 struct intel_display *display = to_intel_display(state);
 struct drm_modeset_acquire_ctx *ctx = state->base.acquire_ctx;
 struct intel_crtc *crtc;

 for_each_intel_crtc(display->drm, crtc) {
  if (modeset_lock_is_held(ctx, &crtc->base.mutex))
   return;
 }

 drm_WARN(display->drm, 1, "Global state not read locked\n");
}

struct intel_global_state *
intel_atomic_get_global_obj_state(struct intel_atomic_state *state,
      struct intel_global_obj *obj)
{
 struct intel_display *display = to_intel_display(state);
 int index, num_objs, i;
 size_t size;
 struct __intel_global_objs_state *arr;
 struct intel_global_state *obj_state;

 for (i = 0; i < state->num_global_objs; i++)
  if (obj == state->global_objs[i].ptr)
   return state->global_objs[i].state;

 assert_global_state_read_locked(state);

 num_objs = state->num_global_objs + 1;
 size = sizeof(*state->global_objs) * num_objs;
 arr = krealloc(state->global_objs, size, GFP_KERNEL);
 if (!arr)
  return ERR_PTR(-ENOMEM);

 state->global_objs = arr;
 index = state->num_global_objs;
 memset(&state->global_objs[index], 0, sizeof(*state->global_objs));

 obj_state = obj->funcs->atomic_duplicate_state(obj);
 if (!obj_state)
  return ERR_PTR(-ENOMEM);

 obj_state->obj = obj;
 obj_state->changed = false;
 obj_state->serialized = false;
 obj_state->commit = NULL;

 kref_init(&obj_state->ref);

 state->global_objs[index].state = obj_state;
 state->global_objs[index].old_state =
  intel_atomic_global_state_get(obj->state);
 state->global_objs[index].new_state = obj_state;
 state->global_objs[index].ptr = obj;
 obj_state->state = state;

 state->num_global_objs = num_objs;

 drm_dbg_atomic(display->drm, "Added new global object %p state %p to %p\n",
         obj, obj_state, state);

 return obj_state;
}

struct intel_global_state *
intel_atomic_get_old_global_obj_state(struct intel_atomic_state *state,
          struct intel_global_obj *obj)
{
 int i;

 for (i = 0; i < state->num_global_objs; i++)
  if (obj == state->global_objs[i].ptr)
   return state->global_objs[i].old_state;

 return NULL;
}

struct intel_global_state *
intel_atomic_get_new_global_obj_state(struct intel_atomic_state *state,
          struct intel_global_obj *obj)
{
 int i;

 for (i = 0; i < state->num_global_objs; i++)
  if (obj == state->global_objs[i].ptr)
   return state->global_objs[i].new_state;

 return NULL;
}

void intel_atomic_swap_global_state(struct intel_atomic_state *state)
{
 struct intel_display *display = to_intel_display(state);
 struct intel_global_state *old_obj_state, *new_obj_state;
 struct intel_global_obj *obj;
 int i;

 for_each_oldnew_global_obj_in_state(state, obj, old_obj_state,
         new_obj_state, i) {
  drm_WARN_ON(display->drm, obj->state != old_obj_state);

  /*
   * If the new state wasn't modified (and properly
   * locked for write access) we throw it away.
 */
  if (!new_obj_state->changed)
   continue;

  assert_global_state_write_locked(display);

  old_obj_state->state = state;
  new_obj_state->state = NULL;

  state->global_objs[i].state = old_obj_state;

  intel_atomic_global_state_put(obj->state);
  obj->state = intel_atomic_global_state_get(new_obj_state);
 }
}

void intel_atomic_clear_global_state(struct intel_atomic_state *state)
{
 int i;

 for (i = 0; i < state->num_global_objs; i++) {
  intel_atomic_global_state_put(state->global_objs[i].old_state);
  intel_atomic_global_state_put(state->global_objs[i].new_state);

  state->global_objs[i].ptr = NULL;
  state->global_objs[i].state = NULL;
  state->global_objs[i].old_state = NULL;
  state->global_objs[i].new_state = NULL;
 }
 state->num_global_objs = 0;
}

int intel_atomic_lock_global_state(struct intel_global_state *obj_state)
{
 struct intel_atomic_state *state = obj_state->state;
 struct intel_display *display = to_intel_display(state);
 struct intel_crtc *crtc;

 for_each_intel_crtc(display->drm, crtc) {
  int ret;

  ret = drm_modeset_lock(&crtc->base.mutex,
           state->base.acquire_ctx);
  if (ret)
   return ret;
 }

 obj_state->changed = true;

 return 0;
}

int intel_atomic_serialize_global_state(struct intel_global_state *obj_state)
{
 int ret;

 ret = intel_atomic_lock_global_state(obj_state);
 if (ret)
  return ret;

 obj_state->serialized = true;

 return 0;
}

bool
intel_atomic_global_state_is_serialized(struct intel_atomic_state *state)
{
 struct intel_display *display = to_intel_display(state);
 struct intel_crtc *crtc;

 for_each_intel_crtc(display->drm, crtc)
  if (!intel_atomic_get_new_crtc_state(state, crtc))
   return false;
 return true;
}

int
intel_atomic_global_state_setup_commit(struct intel_atomic_state *state)
{
 const struct intel_global_state *old_obj_state;
 struct intel_global_state *new_obj_state;
 struct intel_global_obj *obj;
 int i;

 for_each_oldnew_global_obj_in_state(state, obj, old_obj_state,
         new_obj_state, i) {
  struct intel_global_commit *commit = NULL;

  if (new_obj_state->serialized) {
   /*
    * New commit which is going to be completed
    * after the hardware reprogramming is done.
 */
   commit = commit_new();
   if (!commit)
    return -ENOMEM;
  } else if (new_obj_state->changed) {
   /*
    * We're going to swap to this state, so carry the
    * previous commit along, in case it's not yet done.
 */
   commit = commit_get(old_obj_state->commit);
  }

  new_obj_state->commit = commit;
 }

 return 0;
}

int
intel_atomic_global_state_wait_for_dependencies(struct intel_atomic_state *state)
{
 struct intel_display *display = to_intel_display(state);
 const struct intel_global_state *old_obj_state;
 struct intel_global_obj *obj;
 int i;

 for_each_old_global_obj_in_state(state, obj, old_obj_state, i) {
  struct intel_global_commit *commit = old_obj_state->commit;
  long ret;

  if (!commit)
   continue;

  ret = wait_for_completion_timeout(&commit->done, 10 * HZ);
  if (ret == 0) {
   drm_err(display->drm, "global state timed out\n");
   return -ETIMEDOUT;
  }
 }

 return 0;
}

void
intel_atomic_global_state_commit_done(struct intel_atomic_state *state)
{
 const struct intel_global_state *new_obj_state;
 struct intel_global_obj *obj;
 int i;

 for_each_new_global_obj_in_state(state, obj, new_obj_state, i) {
  struct intel_global_commit *commit = new_obj_state->commit;

  if (!new_obj_state->serialized)
   continue;

  complete_all(&commit->done);
 }
}