// SPDX-License-Identifier: MIT
/*
* Copyright © 2020 Intel Corporation
*/
#include <linux/dma-resv.h>
#include "i915_gem_ww.h"
#include "gem/i915_gem_object.h"
void i915_gem_ww_ctx_init(struct i915_gem_ww_ctx *ww, bool intr)
{
ww_acquire_init(&ww->ctx, &reservation_ww_class);
INIT_LIST_HEAD(&ww->obj_list);
ww->intr = intr;
ww->contended = NULL;
}
static void i915_gem_ww_ctx_unlock_all(struct i915_gem_ww_ctx *ww)
{
struct drm_i915_gem_object *obj;
while ((obj = list_first_entry_or_null(&ww->obj_list, struct drm_i915_gem_object, obj_link))) {
list_del(&obj->obj_link);
i915_gem_object_unlock(obj);
i915_gem_object_put(obj);
}
}
void i915_gem_ww_unlock_single(struct drm_i915_gem_object *obj)
{
list_del(&obj->obj_link);
i915_gem_object_unlock(obj);
i915_gem_object_put(obj);
}
void i915_gem_ww_ctx_fini(struct i915_gem_ww_ctx *ww)
{
i915_gem_ww_ctx_unlock_all(ww);
WARN_ON(ww->contended);
ww_acquire_fini(&ww->ctx);
}
int __must_check i915_gem_ww_ctx_backoff(struct i915_gem_ww_ctx *ww)
{
int ret = 0;
if (WARN_ON(!ww->contended))
return -EINVAL;
i915_gem_ww_ctx_unlock_all(ww);
if (ww->intr)
ret = dma_resv_lock_slow_interruptible(ww->contended->base.resv, &ww->ctx);
else
dma_resv_lock_slow(ww->contended->base.resv, &ww->ctx);
if (!ret)
list_add_tail(&ww->contended->obj_link, &ww->obj_list);
else
i915_gem_object_put(ww->contended);
ww->contended = NULL;
return ret;
}