LXR linux/drivers/gpu/drm/i915/i915_gem

   1// SPDX-License-Identifier: MIT
   2/*
   3 * Copyright © 2020 Intel Corporation
   4 */
   5#include <linux/dma-resv.h>
   6#include "i915_gem_ww.h"
   7#include "gem/i915_gem_object.h"
   8
   9void i915_gem_ww_ctx_init(struct i915_gem_ww_ctx *ww, bool intr)
  10{
  11        ww_acquire_init(&ww->ctx, &reservation_ww_class);
  12        INIT_LIST_HEAD(&ww->obj_list);
  13        ww->intr = intr;
  14        ww->contended = NULL;
  15}
  16
  17static void i915_gem_ww_ctx_unlock_all(struct i915_gem_ww_ctx *ww)
  18{
  19        struct drm_i915_gem_object *obj;
  20
  21        while ((obj = list_first_entry_or_null(&ww->obj_list, struct drm_i915_gem_object, obj_link))) {
  22                list_del(&obj->obj_link);
  23                i915_gem_object_unlock(obj);
  24                i915_gem_object_put(obj);
  25        }
  26}
  27
  28void i915_gem_ww_unlock_single(struct drm_i915_gem_object *obj)
  29{
  30        list_del(&obj->obj_link);
  31        i915_gem_object_unlock(obj);
  32        i915_gem_object_put(obj);
  33}
  34
  35void i915_gem_ww_ctx_fini(struct i915_gem_ww_ctx *ww)
  36{
  37        i915_gem_ww_ctx_unlock_all(ww);
  38        WARN_ON(ww->contended);
  39        ww_acquire_fini(&ww->ctx);
  40}
  41
  42int __must_check i915_gem_ww_ctx_backoff(struct i915_gem_ww_ctx *ww)
  43{
  44        int ret = 0;
  45
  46        if (WARN_ON(!ww->contended))
  47                return -EINVAL;
  48
  49        i915_gem_ww_ctx_unlock_all(ww);
  50        if (ww->intr)
  51                ret = dma_resv_lock_slow_interruptible(ww->contended->base.resv, &ww->ctx);
  52        else
  53                dma_resv_lock_slow(ww->contended->base.resv, &ww->ctx);
  54
  55        if (!ret)
  56                list_add_tail(&ww->contended->obj_link, &ww->obj_list);
  57        else
  58                i915_gem_object_put(ww->contended);
  59
  60        ww->contended = NULL;
  61
  62        return ret;
  63}
  64