/*
* Copyright © 2008-2010 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <eric@anholt.net>
* Chris Wilson <chris@chris-wilson.co.uuk>
*
*/
#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include "intel_drv.h"
#include "i915_trace.h"
static bool
mark_free(struct i915_vma *vma, struct list_head *unwind)
{
if (vma->pin_count)
return false;
if (WARN_ON(!list_empty(&vma->exec_list)))
return false;
list_add(&vma->exec_list, unwind);
return drm_mm_scan_add_block(&vma->node);
}
/**
* i915_gem_evict_something - Evict vmas to make room for binding a new one
* @dev: drm_device
* @vm: address space to evict from
* @min_size: size of the desired free space
* @alignment: alignment constraint of the desired free space
* @cache_level: cache_level for the desired space
* @start: start (inclusive) of the range from which to evict objects
* @end: end (exclusive) of the range from which to evict objects
* @flags: additional flags to control the eviction algorithm
*
* This function will try to evict vmas until a free space satisfying the
* requirements is found. Callers must check first whether any such hole exists
* already before calling this function.
*
* This function is used by the object/vma binding code.
*
* Since this function is only used to free up virtual address space it only
* ignores pinned vmas, and not object where the backing storage itself is
* pinned. Hence obj->pages_pin_count does not protect against eviction.
*
* To clarify: This is for freeing up virtual address space, not for freeing
* memory in e.g. the shrinker.
*/
int
i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
int min_size, unsigned alignment, unsigned cache_level,
unsigned long start, unsigned long end,
unsigned flags)
{
struct list_head eviction_list, unwind_list;
struct i915_vma *vma;
int ret = 0;
int pass = 0;
trace_i915_gem_evict(dev, min_size, alignment, flags);
/*
* The goal is to evict objects and amalgamate space in LRU order.
* The oldest idle objects reside on the inactive list, which is in
* retirement order. The next objects to retire are those on the (per
* ring) active list that do not have an outstanding flush. Once the
* hardware reports completion (the seqno is updated after the
* batchbuffer has been finished) the clean buffer objects would
* be retired to the inactive list. Any dirty objects would be added
* to the tail of the flushing list. So after processing the clean
* active objects we need to emit a MI_FLUSH to retire the flushing
* list, hence the retirement order of the flushing list is in
* advance of the dirty objects on the active lists.
*
* The retirement sequence is thus:
* 1. Inactive objects (already retired)
* 2. Clean active objects
* 3. Flushing list
* 4. Dirty active objects.
*
* On each list, the oldest objects lie at the HEAD with the freshest
* object on the TAIL.
*/
INIT_LIST_HEAD(&unwind_list);
if (start != 0 || end != vm->total) {
drm_mm_init_scan_with_range(&vm->mm, min_size,
alignment, cache_level,
start, end);
} else
drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
search_again:
/* First see if there is a large enough contiguous idle region... */
list_for_each_entry(vma, &vm->inactive_list, mm_list) {
if (mark_free(vma, &unwind_list))
goto found;
}
if (flags & PIN_NONBLOCK)
goto none;
/* Now merge in the soon-to-be-expired objects... */
list_for_each_entry(vma, &vm->active_list, mm_list) {
if (mark_free(vma, &unwind_list))
goto found;
}
none:
/* Nothing found, clean up and bail out! */
while (!list_empty(&unwind_list)) {
vma = list_first_entry(&unwind_list,
struct i915_vma,
exec_list);
ret = drm_mm_scan_remove_block(&vma->node);
BUG_ON(ret);
list_del_init(&vma->exec_list);
}
/* Can we unpin some objects such as idle hw contents,
* or pending flips?
*/
if (flags & PIN_NONBLOCK)
return -ENOSPC;
/* Only idle the GPU and repeat the search once */
if (pass++ == 0) {
ret = i915_gpu_idle(dev);
if (ret)
return ret;
i915_gem_retire_requests(dev);
goto search_again;
}
/* If we still have pending pageflip completions, drop
* back to userspace to give our workqueues time to
* acquire our locks and unpin the old scanouts.
*/
return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC;
found:
/* drm_mm doesn't allow any other other operations while
* scanning, therefore store to be evicted objects on a
* temporary list. */
INIT_LIST_HEAD(&eviction_list);
while (!list_empty(&unwind_list)) {
vma = list_first_entry(&unwind_list,
struct i915_vma,
exec_list);
if (drm_mm_scan_remove_block(&vma->node)) {
list_move(&vma->exec_list, &eviction_list);
drm_gem_object_reference(&vma->obj->base);
continue;
}
list_del_init(&vma->exec_list);
}
/* Unbinding will emit any required flushes */
while (!list_empty(&eviction_list)) {
struct drm_gem_object *obj;
vma = list_first_entry(&eviction_list,
struct i915_vma,
exec_list);
obj = &vma->obj->base;
list_del_init(&vma->exec_list);
if (ret == 0)
ret = i915_vma_unbind(vma);
drm_gem_object_unreference(obj);
}
return ret;
}
/**
* i915_gem_evict_vm - Evict all idle vmas from a vm
* @vm: Address space to cleanse
* @do_idle: Boolean directing whether to idle first.
*
* This function evicts all idles vmas from a vm. If all unpinned vmas should be
* evicted the @do_idle needs to be set to true.
*
* This is used by the execbuf code as a last-ditch effort to defragment the
* address space.
*
* To clarify: This is for freeing up virtual address space, not for freeing
* memory in e.g. the shrinker.
*/
int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
{
struct i915_vma *vma, *next;
int ret;
WARN_ON(!mutex_is_locked(&vm->dev->struct_mutex));
trace_i915_gem_evict_vm(vm);
if (do_idle) {
ret = i915_gpu_idle(vm->dev);
if (ret)
return ret;
i915_gem_retire_requests(vm->dev);
WARN_ON(!list_empty(&vm->active_list));
}
list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
if (vma->pin_count == 0)
WARN_ON(i915_vma_unbind(vma));
return 0;
}
