freebsd-skq/sys/dev/drm2/i915/i915_gem_execbuffer.c
Jean-Sébastien Pédron 25a984748c drm/i915: Reduce diff with Linux 3.8
There is no functional change. The goal is to ease the future update to
Linux 3.8's i915 driver.

MFC after:	2 months
2015-10-31 15:09:31 +00:00

1558 lines
41 KiB
C

/*
* 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.uk>
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <dev/drm2/drmP.h>
#include <dev/drm2/drm.h>
#include <dev/drm2/i915/i915_drm.h>
#include <dev/drm2/i915/i915_drv.h>
#include <dev/drm2/i915/intel_drv.h>
#include <sys/limits.h>
#include <sys/sf_buf.h>
struct change_domains {
uint32_t invalidate_domains;
uint32_t flush_domains;
uint32_t flush_rings;
uint32_t flips;
};
/*
* Set the next domain for the specified object. This
* may not actually perform the necessary flushing/invaliding though,
* as that may want to be batched with other set_domain operations
*
* This is (we hope) the only really tricky part of gem. The goal
* is fairly simple -- track which caches hold bits of the object
* and make sure they remain coherent. A few concrete examples may
* help to explain how it works. For shorthand, we use the notation
* (read_domains, write_domain), e.g. (CPU, CPU) to indicate the
* a pair of read and write domain masks.
*
* Case 1: the batch buffer
*
* 1. Allocated
* 2. Written by CPU
* 3. Mapped to GTT
* 4. Read by GPU
* 5. Unmapped from GTT
* 6. Freed
*
* Let's take these a step at a time
*
* 1. Allocated
* Pages allocated from the kernel may still have
* cache contents, so we set them to (CPU, CPU) always.
* 2. Written by CPU (using pwrite)
* The pwrite function calls set_domain (CPU, CPU) and
* this function does nothing (as nothing changes)
* 3. Mapped by GTT
* This function asserts that the object is not
* currently in any GPU-based read or write domains
* 4. Read by GPU
* i915_gem_execbuffer calls set_domain (COMMAND, 0).
* As write_domain is zero, this function adds in the
* current read domains (CPU+COMMAND, 0).
* flush_domains is set to CPU.
* invalidate_domains is set to COMMAND
* clflush is run to get data out of the CPU caches
* then i915_dev_set_domain calls i915_gem_flush to
* emit an MI_FLUSH and drm_agp_chipset_flush
* 5. Unmapped from GTT
* i915_gem_object_unbind calls set_domain (CPU, CPU)
* flush_domains and invalidate_domains end up both zero
* so no flushing/invalidating happens
* 6. Freed
* yay, done
*
* Case 2: The shared render buffer
*
* 1. Allocated
* 2. Mapped to GTT
* 3. Read/written by GPU
* 4. set_domain to (CPU,CPU)
* 5. Read/written by CPU
* 6. Read/written by GPU
*
* 1. Allocated
* Same as last example, (CPU, CPU)
* 2. Mapped to GTT
* Nothing changes (assertions find that it is not in the GPU)
* 3. Read/written by GPU
* execbuffer calls set_domain (RENDER, RENDER)
* flush_domains gets CPU
* invalidate_domains gets GPU
* clflush (obj)
* MI_FLUSH and drm_agp_chipset_flush
* 4. set_domain (CPU, CPU)
* flush_domains gets GPU
* invalidate_domains gets CPU
* wait_rendering (obj) to make sure all drawing is complete.
* This will include an MI_FLUSH to get the data from GPU
* to memory
* clflush (obj) to invalidate the CPU cache
* Another MI_FLUSH in i915_gem_flush (eliminate this somehow?)
* 5. Read/written by CPU
* cache lines are loaded and dirtied
* 6. Read written by GPU
* Same as last GPU access
*
* Case 3: The constant buffer
*
* 1. Allocated
* 2. Written by CPU
* 3. Read by GPU
* 4. Updated (written) by CPU again
* 5. Read by GPU
*
* 1. Allocated
* (CPU, CPU)
* 2. Written by CPU
* (CPU, CPU)
* 3. Read by GPU
* (CPU+RENDER, 0)
* flush_domains = CPU
* invalidate_domains = RENDER
* clflush (obj)
* MI_FLUSH
* drm_agp_chipset_flush
* 4. Updated (written) by CPU again
* (CPU, CPU)
* flush_domains = 0 (no previous write domain)
* invalidate_domains = 0 (no new read domains)
* 5. Read by GPU
* (CPU+RENDER, 0)
* flush_domains = CPU
* invalidate_domains = RENDER
* clflush (obj)
* MI_FLUSH
* drm_agp_chipset_flush
*/
static void
i915_gem_object_set_to_gpu_domain(struct drm_i915_gem_object *obj,
struct intel_ring_buffer *ring,
struct change_domains *cd)
{
uint32_t invalidate_domains = 0, flush_domains = 0;
/*
* If the object isn't moving to a new write domain,
* let the object stay in multiple read domains
*/
if (obj->base.pending_write_domain == 0)
obj->base.pending_read_domains |= obj->base.read_domains;
/*
* Flush the current write domain if
* the new read domains don't match. Invalidate
* any read domains which differ from the old
* write domain
*/
if (obj->base.write_domain &&
(((obj->base.write_domain != obj->base.pending_read_domains ||
obj->ring != ring)) ||
(obj->fenced_gpu_access && !obj->pending_fenced_gpu_access))) {
flush_domains |= obj->base.write_domain;
invalidate_domains |=
obj->base.pending_read_domains & ~obj->base.write_domain;
}
/*
* Invalidate any read caches which may have
* stale data. That is, any new read domains.
*/
invalidate_domains |= obj->base.pending_read_domains & ~obj->base.read_domains;
if ((flush_domains | invalidate_domains) & I915_GEM_DOMAIN_CPU)
i915_gem_clflush_object(obj);
if (obj->base.pending_write_domain)
cd->flips |= atomic_load_acq_int(&obj->pending_flip);
/* The actual obj->write_domain will be updated with
* pending_write_domain after we emit the accumulated flush for all
* of our domain changes in execbuffers (which clears objects'
* write_domains). So if we have a current write domain that we
* aren't changing, set pending_write_domain to that.
*/
if (flush_domains == 0 && obj->base.pending_write_domain == 0)
obj->base.pending_write_domain = obj->base.write_domain;
cd->invalidate_domains |= invalidate_domains;
cd->flush_domains |= flush_domains;
if (flush_domains & I915_GEM_GPU_DOMAINS)
cd->flush_rings |= intel_ring_flag(obj->ring);
if (invalidate_domains & I915_GEM_GPU_DOMAINS)
cd->flush_rings |= intel_ring_flag(ring);
}
struct eb_objects {
u_long hashmask;
LIST_HEAD(, drm_i915_gem_object) *buckets;
};
static struct eb_objects *
eb_create(int size)
{
struct eb_objects *eb;
eb = malloc(sizeof(*eb),
DRM_I915_GEM, M_WAITOK | M_ZERO);
eb->buckets = hashinit(size, DRM_I915_GEM, &eb->hashmask);
return eb;
}
static void
eb_reset(struct eb_objects *eb)
{
int i;
for (i = 0; i <= eb->hashmask; i++)
LIST_INIT(&eb->buckets[i]);
}
static void
eb_add_object(struct eb_objects *eb, struct drm_i915_gem_object *obj)
{
LIST_INSERT_HEAD(&eb->buckets[obj->exec_handle & eb->hashmask],
obj, exec_node);
}
static struct drm_i915_gem_object *
eb_get_object(struct eb_objects *eb, unsigned long handle)
{
struct drm_i915_gem_object *obj;
LIST_FOREACH(obj, &eb->buckets[handle & eb->hashmask], exec_node) {
if (obj->exec_handle == handle)
return obj;
}
return NULL;
}
static void
eb_destroy(struct eb_objects *eb)
{
free(eb->buckets, DRM_I915_GEM);
free(eb, DRM_I915_GEM);
}
static inline int use_cpu_reloc(struct drm_i915_gem_object *obj)
{
return (obj->base.write_domain == I915_GEM_DOMAIN_CPU ||
obj->cache_level != I915_CACHE_NONE);
}
static int
i915_gem_execbuffer_relocate_entry(struct drm_i915_gem_object *obj,
struct eb_objects *eb,
struct drm_i915_gem_relocation_entry *reloc)
{
struct drm_device *dev = obj->base.dev;
struct drm_gem_object *target_obj;
struct drm_i915_gem_object *target_i915_obj;
uint32_t target_offset;
int ret = -EINVAL;
/* we've already hold a reference to all valid objects */
target_obj = &eb_get_object(eb, reloc->target_handle)->base;
if (unlikely(target_obj == NULL))
return -ENOENT;
target_i915_obj = to_intel_bo(target_obj);
target_offset = target_i915_obj->gtt_offset;
#if WATCH_RELOC
DRM_INFO("%s: obj %p offset %08x target %d "
"read %08x write %08x gtt %08x "
"presumed %08x delta %08x\n",
__func__,
obj,
(int) reloc->offset,
(int) reloc->target_handle,
(int) reloc->read_domains,
(int) reloc->write_domain,
(int) target_offset,
(int) reloc->presumed_offset,
reloc->delta);
#endif
/* The target buffer should have appeared before us in the
* exec_object list, so it should have a GTT space bound by now.
*/
if (unlikely(target_offset == 0)) {
DRM_DEBUG("No GTT space found for object %d\n",
reloc->target_handle);
return ret;
}
/* Validate that the target is in a valid r/w GPU domain */
if (unlikely(reloc->write_domain & (reloc->write_domain - 1))) {
DRM_DEBUG("reloc with multiple write domains: "
"obj %p target %d offset %d "
"read %08x write %08x",
obj, reloc->target_handle,
(int) reloc->offset,
reloc->read_domains,
reloc->write_domain);
return ret;
}
if (unlikely((reloc->write_domain | reloc->read_domains)
& ~I915_GEM_GPU_DOMAINS)) {
DRM_DEBUG("reloc with read/write non-GPU domains: "
"obj %p target %d offset %d "
"read %08x write %08x",
obj, reloc->target_handle,
(int) reloc->offset,
reloc->read_domains,
reloc->write_domain);
return ret;
}
if (unlikely(reloc->write_domain && target_obj->pending_write_domain &&
reloc->write_domain != target_obj->pending_write_domain)) {
DRM_DEBUG("Write domain conflict: "
"obj %p target %d offset %d "
"new %08x old %08x\n",
obj, reloc->target_handle,
(int) reloc->offset,
reloc->write_domain,
target_obj->pending_write_domain);
return ret;
}
target_obj->pending_read_domains |= reloc->read_domains;
target_obj->pending_write_domain |= reloc->write_domain;
/* If the relocation already has the right value in it, no
* more work needs to be done.
*/
if (target_offset == reloc->presumed_offset)
return 0;
/* Check that the relocation address is valid... */
if (unlikely(reloc->offset > obj->base.size - 4)) {
DRM_DEBUG("Relocation beyond object bounds: "
"obj %p target %d offset %d size %d.\n",
obj, reloc->target_handle,
(int) reloc->offset,
(int) obj->base.size);
return ret;
}
if (unlikely(reloc->offset & 3)) {
DRM_DEBUG("Relocation not 4-byte aligned: "
"obj %p target %d offset %d.\n",
obj, reloc->target_handle,
(int) reloc->offset);
return ret;
}
/* We can't wait for rendering with pagefaults disabled */
if (obj->active && (curthread->td_pflags & TDP_NOFAULTING) != 0)
return -EFAULT;
reloc->delta += target_offset;
if (use_cpu_reloc(obj)) {
uint32_t page_offset = reloc->offset & PAGE_MASK;
char *vaddr;
struct sf_buf *sf;
ret = i915_gem_object_set_to_cpu_domain(obj, 1);
if (ret)
return ret;
sf = sf_buf_alloc(obj->pages[OFF_TO_IDX(reloc->offset)],
SFB_NOWAIT);
if (sf == NULL)
return -ENOMEM;
vaddr = (void *)sf_buf_kva(sf);
*(uint32_t *)(vaddr + page_offset) = reloc->delta;
sf_buf_free(sf);
} else {
uint32_t *reloc_entry;
char *reloc_page;
ret = i915_gem_object_set_to_gtt_domain(obj, true);
if (ret)
return ret;
ret = i915_gem_object_put_fence(obj);
if (ret)
return ret;
/* Map the page containing the relocation we're going to perform. */
reloc->offset += obj->gtt_offset;
reloc_page = pmap_mapdev_attr(dev->agp->base + (reloc->offset &
~PAGE_MASK), PAGE_SIZE, PAT_WRITE_COMBINING);
reloc_entry = (uint32_t *)(reloc_page + (reloc->offset &
PAGE_MASK));
*(volatile uint32_t *)reloc_entry = reloc->delta;
pmap_unmapdev((vm_offset_t)reloc_page, PAGE_SIZE);
}
/* Sandybridge PPGTT errata: We need a global gtt mapping for MI and
* pipe_control writes because the gpu doesn't properly redirect them
* through the ppgtt for non_secure batchbuffers. */
if (unlikely(IS_GEN6(dev) &&
reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION &&
!target_i915_obj->has_global_gtt_mapping)) {
i915_gem_gtt_bind_object(target_i915_obj,
target_i915_obj->cache_level);
}
/* and update the user's relocation entry */
reloc->presumed_offset = target_offset;
return 0;
}
static int
i915_gem_execbuffer_relocate_object(struct drm_i915_gem_object *obj,
struct eb_objects *eb)
{
#define N_RELOC(x) ((x) / sizeof(struct drm_i915_gem_relocation_entry))
struct drm_i915_gem_relocation_entry stack_reloc[N_RELOC(512)];
struct drm_i915_gem_relocation_entry *user_relocs;
struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
int remain, ret;
user_relocs = (void *)(uintptr_t)entry->relocs_ptr;
remain = entry->relocation_count;
while (remain) {
struct drm_i915_gem_relocation_entry *r = stack_reloc;
int count = remain;
if (count > DRM_ARRAY_SIZE(stack_reloc))
count = DRM_ARRAY_SIZE(stack_reloc);
remain -= count;
ret = -copyin_nofault(user_relocs, r, count*sizeof(r[0]));
if (ret != 0)
return (ret);
do {
u64 offset = r->presumed_offset;
ret = i915_gem_execbuffer_relocate_entry(obj, eb, r);
if (ret)
return ret;
if (r->presumed_offset != offset &&
copyout_nofault(&r->presumed_offset,
&user_relocs->presumed_offset,
sizeof(r->presumed_offset))) {
return -EFAULT;
}
user_relocs++;
r++;
} while (--count);
}
return 0;
#undef N_RELOC
}
static int
i915_gem_execbuffer_relocate_object_slow(struct drm_i915_gem_object *obj,
struct eb_objects *eb,
struct drm_i915_gem_relocation_entry *relocs)
{
const struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
int i, ret;
for (i = 0; i < entry->relocation_count; i++) {
ret = i915_gem_execbuffer_relocate_entry(obj, eb, &relocs[i]);
if (ret)
return ret;
}
return 0;
}
static int
i915_gem_execbuffer_relocate(struct drm_device *dev,
struct eb_objects *eb,
struct list_head *objects)
{
struct drm_i915_gem_object *obj;
int ret, pflags;
/* Try to move as many of the relocation targets off the active list
* to avoid unnecessary fallbacks to the slow path, as we cannot wait
* for the retirement with pagefaults disabled.
*/
i915_gem_retire_requests(dev);
ret = 0;
/* This is the fast path and we cannot handle a pagefault whilst
* holding the device lock lest the user pass in the relocations
* contained within a mmaped bo. For in such a case we, the page
* fault handler would call i915_gem_fault() and we would try to
* acquire the device lock again. Obviously this is bad.
*/
pflags = vm_fault_disable_pagefaults();
list_for_each_entry(obj, objects, exec_list) {
ret = i915_gem_execbuffer_relocate_object(obj, eb);
if (ret)
break;
}
vm_fault_enable_pagefaults(pflags);
return ret;
}
#define __EXEC_OBJECT_HAS_FENCE (1<<31)
static int
need_reloc_mappable(struct drm_i915_gem_object *obj)
{
struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
return entry->relocation_count && !use_cpu_reloc(obj);
}
static int
pin_and_fence_object(struct drm_i915_gem_object *obj,
struct intel_ring_buffer *ring)
{
struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
bool has_fenced_gpu_access = INTEL_INFO(ring->dev)->gen < 4;
bool need_fence, need_mappable;
int ret;
need_fence =
has_fenced_gpu_access &&
entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
obj->tiling_mode != I915_TILING_NONE;
need_mappable = need_fence || need_reloc_mappable(obj);
ret = i915_gem_object_pin(obj, entry->alignment, need_mappable);
if (ret)
return ret;
if (has_fenced_gpu_access) {
if (entry->flags & EXEC_OBJECT_NEEDS_FENCE) {
ret = i915_gem_object_get_fence(obj);
if (ret)
goto err_unpin;
if (i915_gem_object_pin_fence(obj))
entry->flags |= __EXEC_OBJECT_HAS_FENCE;
obj->pending_fenced_gpu_access = true;
}
}
entry->offset = obj->gtt_offset;
return 0;
err_unpin:
i915_gem_object_unpin(obj);
return ret;
}
static int
i915_gem_execbuffer_reserve(struct intel_ring_buffer *ring,
struct drm_file *file,
struct list_head *objects)
{
drm_i915_private_t *dev_priv;
struct drm_i915_gem_object *obj;
struct list_head ordered_objects;
bool has_fenced_gpu_access = INTEL_INFO(ring->dev)->gen < 4;
int retry;
int ret;
dev_priv = ring->dev->dev_private;
INIT_LIST_HEAD(&ordered_objects);
while (!list_empty(objects)) {
struct drm_i915_gem_exec_object2 *entry;
bool need_fence, need_mappable;
obj = list_first_entry(objects,
struct drm_i915_gem_object,
exec_list);
entry = obj->exec_entry;
need_fence =
has_fenced_gpu_access &&
entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
obj->tiling_mode != I915_TILING_NONE;
need_mappable = need_fence || need_reloc_mappable(obj);
if (need_mappable)
list_move(&obj->exec_list, &ordered_objects);
else
list_move_tail(&obj->exec_list, &ordered_objects);
obj->base.pending_read_domains = 0;
obj->base.pending_write_domain = 0;
}
list_splice(&ordered_objects, objects);
/* Attempt to pin all of the buffers into the GTT.
* This is done in 3 phases:
*
* 1a. Unbind all objects that do not match the GTT constraints for
* the execbuffer (fenceable, mappable, alignment etc).
* 1b. Increment pin count for already bound objects.
* 2. Bind new objects.
* 3. Decrement pin count.
*
* This avoid unnecessary unbinding of later objects in order to make
* room for the earlier objects *unless* we need to defragment.
*/
retry = 0;
do {
ret = 0;
/* Unbind any ill-fitting objects or pin. */
list_for_each_entry(obj, objects, exec_list) {
struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
bool need_fence, need_mappable;
if (!obj->gtt_space)
continue;
need_fence =
has_fenced_gpu_access &&
entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
obj->tiling_mode != I915_TILING_NONE;
need_mappable = need_fence || need_reloc_mappable(obj);
if ((entry->alignment && obj->gtt_offset & (entry->alignment - 1)) ||
(need_mappable && !obj->map_and_fenceable))
ret = i915_gem_object_unbind(obj);
else
ret = pin_and_fence_object(obj, ring);
if (ret)
goto err;
}
/* Bind fresh objects */
list_for_each_entry(obj, objects, exec_list) {
if (obj->gtt_space)
continue;
ret = pin_and_fence_object(obj, ring);
if (ret) {
int ret_ignore;
/* This can potentially raise a harmless
* -EINVAL if we failed to bind in the above
* call. It cannot raise -EINTR since we know
* that the bo is freshly bound and so will
* not need to be flushed or waited upon.
*/
ret_ignore = i915_gem_object_unbind(obj);
(void)ret_ignore;
if (obj->gtt_space != NULL)
printf("%s: gtt_space\n", __func__);
break;
}
}
/* Decrement pin count for bound objects */
list_for_each_entry(obj, objects, exec_list) {
struct drm_i915_gem_exec_object2 *entry;
if (!obj->gtt_space)
continue;
entry = obj->exec_entry;
if (entry->flags & __EXEC_OBJECT_HAS_FENCE) {
i915_gem_object_unpin_fence(obj);
entry->flags &= ~__EXEC_OBJECT_HAS_FENCE;
}
i915_gem_object_unpin(obj);
/* ... and ensure ppgtt mapping exist if needed. */
if (dev_priv->mm.aliasing_ppgtt && !obj->has_aliasing_ppgtt_mapping) {
i915_ppgtt_bind_object(dev_priv->mm.aliasing_ppgtt,
obj, obj->cache_level);
obj->has_aliasing_ppgtt_mapping = 1;
}
}
if (ret != -ENOSPC || retry > 1)
return ret;
/* First attempt, just clear anything that is purgeable.
* Second attempt, clear the entire GTT.
*/
ret = i915_gem_evict_everything(ring->dev, retry == 0);
if (ret)
return ret;
retry++;
} while (1);
err:
list_for_each_entry_continue_reverse(obj, objects, exec_list) {
struct drm_i915_gem_exec_object2 *entry;
if (!obj->gtt_space)
continue;
entry = obj->exec_entry;
if (entry->flags & __EXEC_OBJECT_HAS_FENCE) {
i915_gem_object_unpin_fence(obj);
entry->flags &= ~__EXEC_OBJECT_HAS_FENCE;
}
i915_gem_object_unpin(obj);
}
return ret;
}
static int
i915_gem_execbuffer_relocate_slow(struct drm_device *dev,
struct drm_file *file,
struct intel_ring_buffer *ring,
struct list_head *objects,
struct eb_objects *eb,
struct drm_i915_gem_exec_object2 *exec,
int count)
{
struct drm_i915_gem_relocation_entry *reloc;
struct drm_i915_gem_object *obj;
int *reloc_offset;
int i, total, ret;
/* We may process another execbuffer during the unlock... */
while (!list_empty(objects)) {
obj = list_first_entry(objects,
struct drm_i915_gem_object,
exec_list);
list_del_init(&obj->exec_list);
drm_gem_object_unreference(&obj->base);
}
DRM_UNLOCK(dev);
total = 0;
for (i = 0; i < count; i++)
total += exec[i].relocation_count;
reloc_offset = malloc(count * sizeof(*reloc_offset), DRM_I915_GEM,
M_WAITOK | M_ZERO);
reloc = malloc(total * sizeof(*reloc), DRM_I915_GEM, M_WAITOK | M_ZERO);
total = 0;
for (i = 0; i < count; i++) {
struct drm_i915_gem_relocation_entry *user_relocs;
user_relocs = (void *)(uintptr_t)exec[i].relocs_ptr;
ret = -copyin(user_relocs, reloc + total,
exec[i].relocation_count * sizeof(*reloc));
if (ret != 0) {
DRM_LOCK(dev);
goto err;
}
reloc_offset[i] = total;
total += exec[i].relocation_count;
}
ret = i915_mutex_lock_interruptible(dev);
if (ret) {
DRM_LOCK(dev);
goto err;
}
/* reacquire the objects */
eb_reset(eb);
for (i = 0; i < count; i++) {
struct drm_i915_gem_object *obj;
obj = to_intel_bo(drm_gem_object_lookup(dev, file,
exec[i].handle));
if (&obj->base == NULL) {
DRM_DEBUG("Invalid object handle %d at index %d\n",
exec[i].handle, i);
ret = -ENOENT;
goto err;
}
list_add_tail(&obj->exec_list, objects);
obj->exec_handle = exec[i].handle;
obj->exec_entry = &exec[i];
eb_add_object(eb, obj);
}
ret = i915_gem_execbuffer_reserve(ring, file, objects);
if (ret)
goto err;
list_for_each_entry(obj, objects, exec_list) {
int offset = obj->exec_entry - exec;
ret = i915_gem_execbuffer_relocate_object_slow(obj, eb,
reloc + reloc_offset[offset]);
if (ret)
goto err;
}
/* Leave the user relocations as are, this is the painfully slow path,
* and we want to avoid the complication of dropping the lock whilst
* having buffers reserved in the aperture and so causing spurious
* ENOSPC for random operations.
*/
err:
free(reloc, DRM_I915_GEM);
free(reloc_offset, DRM_I915_GEM);
return ret;
}
static int
i915_gem_execbuffer_flush(struct drm_device *dev,
uint32_t invalidate_domains,
uint32_t flush_domains,
uint32_t flush_rings)
{
drm_i915_private_t *dev_priv = dev->dev_private;
int i, ret;
if (flush_domains & I915_GEM_DOMAIN_CPU)
intel_gtt_chipset_flush();
if (flush_domains & I915_GEM_DOMAIN_GTT)
wmb();
if ((flush_domains | invalidate_domains) & I915_GEM_GPU_DOMAINS) {
for (i = 0; i < I915_NUM_RINGS; i++)
if (flush_rings & (1 << i)) {
ret = i915_gem_flush_ring(&dev_priv->rings[i],
invalidate_domains, flush_domains);
if (ret)
return ret;
}
}
return 0;
}
static int
i915_gem_execbuffer_wait_for_flips(struct intel_ring_buffer *ring, u32 flips)
{
u32 plane, flip_mask;
int ret;
/* Check for any pending flips. As we only maintain a flip queue depth
* of 1, we can simply insert a WAIT for the next display flip prior
* to executing the batch and avoid stalling the CPU.
*/
for (plane = 0; flips >> plane; plane++) {
if (((flips >> plane) & 1) == 0)
continue;
if (plane)
flip_mask = MI_WAIT_FOR_PLANE_B_FLIP;
else
flip_mask = MI_WAIT_FOR_PLANE_A_FLIP;
ret = intel_ring_begin(ring, 2);
if (ret)
return ret;
intel_ring_emit(ring, MI_WAIT_FOR_EVENT | flip_mask);
intel_ring_emit(ring, MI_NOOP);
intel_ring_advance(ring);
}
return 0;
}
static int
i915_gem_execbuffer_move_to_gpu(struct intel_ring_buffer *ring,
struct list_head *objects)
{
struct drm_i915_gem_object *obj;
struct change_domains cd;
int ret;
memset(&cd, 0, sizeof(cd));
list_for_each_entry(obj, objects, exec_list)
i915_gem_object_set_to_gpu_domain(obj, ring, &cd);
if (cd.invalidate_domains | cd.flush_domains) {
#if WATCH_EXEC
DRM_INFO("%s: invalidate_domains %08x flush_domains %08x\n",
__func__,
cd.invalidate_domains,
cd.flush_domains);
#endif
ret = i915_gem_execbuffer_flush(ring->dev,
cd.invalidate_domains,
cd.flush_domains,
cd.flush_rings);
if (ret)
return ret;
}
if (cd.flips) {
ret = i915_gem_execbuffer_wait_for_flips(ring, cd.flips);
if (ret)
return ret;
}
list_for_each_entry(obj, objects, exec_list) {
ret = i915_gem_object_sync(obj, ring);
if (ret)
return ret;
}
return 0;
}
static bool
i915_gem_check_execbuffer(struct drm_i915_gem_execbuffer2 *exec)
{
return ((exec->batch_start_offset | exec->batch_len) & 0x7) == 0;
}
static int
validate_exec_list(struct drm_i915_gem_exec_object2 *exec, int count,
vm_page_t ***map, int **maplen)
{
vm_page_t *ma;
int i, length, page_count;
/* XXXKIB various limits checking is missing there */
*map = malloc(count * sizeof(*ma), DRM_I915_GEM, M_WAITOK | M_ZERO);
*maplen = malloc(count * sizeof(*maplen), DRM_I915_GEM, M_WAITOK |
M_ZERO);
for (i = 0; i < count; i++) {
/* First check for malicious input causing overflow */
if (exec[i].relocation_count >
INT_MAX / sizeof(struct drm_i915_gem_relocation_entry))
return -EINVAL;
length = exec[i].relocation_count *
sizeof(struct drm_i915_gem_relocation_entry);
if (length == 0) {
(*map)[i] = NULL;
continue;
}
/*
* Since both start and end of the relocation region
* may be not aligned on the page boundary, be
* conservative and request a page slot for each
* partial page. Thus +2.
*/
page_count = howmany(length, PAGE_SIZE) + 2;
ma = (*map)[i] = malloc(page_count * sizeof(vm_page_t),
DRM_I915_GEM, M_WAITOK | M_ZERO);
(*maplen)[i] = vm_fault_quick_hold_pages(
&curproc->p_vmspace->vm_map, exec[i].relocs_ptr, length,
VM_PROT_READ | VM_PROT_WRITE, ma, page_count);
if ((*maplen)[i] == -1) {
free(ma, DRM_I915_GEM);
(*map)[i] = NULL;
return -EFAULT;
}
}
return 0;
}
static void
i915_gem_execbuffer_move_to_active(struct list_head *objects,
struct intel_ring_buffer *ring,
u32 seqno)
{
struct drm_i915_gem_object *obj;
uint32_t old_read, old_write;
list_for_each_entry(obj, objects, exec_list) {
old_read = obj->base.read_domains;
old_write = obj->base.write_domain;
obj->base.read_domains = obj->base.pending_read_domains;
obj->base.write_domain = obj->base.pending_write_domain;
obj->fenced_gpu_access = obj->pending_fenced_gpu_access;
i915_gem_object_move_to_active(obj, ring, seqno);
if (obj->base.write_domain) {
obj->dirty = 1;
obj->pending_gpu_write = true;
list_move_tail(&obj->gpu_write_list,
&ring->gpu_write_list);
if (obj->pin_count) /* check for potential scanout */
intel_mark_busy(ring->dev, obj);
}
CTR3(KTR_DRM, "object_change_domain move_to_active %p %x %x",
obj, old_read, old_write);
}
intel_mark_busy(ring->dev, NULL);
}
int i915_gem_sync_exec_requests;
static void
i915_gem_execbuffer_retire_commands(struct drm_device *dev,
struct drm_file *file,
struct intel_ring_buffer *ring)
{
struct drm_i915_gem_request *request;
u32 invalidate;
/*
* Ensure that the commands in the batch buffer are
* finished before the interrupt fires.
*
* The sampler always gets flushed on i965 (sigh).
*/
invalidate = I915_GEM_DOMAIN_COMMAND;
if (INTEL_INFO(dev)->gen >= 4)
invalidate |= I915_GEM_DOMAIN_SAMPLER;
if (ring->flush(ring, invalidate, 0)) {
i915_gem_next_request_seqno(ring);
return;
}
/* Add a breadcrumb for the completion of the batch buffer */
request = malloc(sizeof(*request), DRM_I915_GEM, M_WAITOK | M_ZERO);
if (request == NULL || i915_add_request(ring, file, request)) {
i915_gem_next_request_seqno(ring);
free(request, DRM_I915_GEM);
} else if (i915_gem_sync_exec_requests) {
i915_wait_request(ring, request->seqno);
i915_gem_retire_requests(dev);
}
}
static void
i915_gem_fix_mi_batchbuffer_end(struct drm_i915_gem_object *batch_obj,
uint32_t batch_start_offset, uint32_t batch_len)
{
char *mkva;
uint64_t po_r, po_w;
uint32_t cmd;
po_r = batch_obj->base.dev->agp->base + batch_obj->gtt_offset +
batch_start_offset + batch_len;
if (batch_len > 0)
po_r -= 4;
mkva = pmap_mapdev_attr(trunc_page(po_r), 2 * PAGE_SIZE,
PAT_WRITE_COMBINING);
po_r &= PAGE_MASK;
cmd = *(uint32_t *)(mkva + po_r);
if (cmd != MI_BATCH_BUFFER_END) {
/*
* batch_len != 0 due to the check at the start of
* i915_gem_do_execbuffer
*/
if (batch_obj->base.size > batch_start_offset + batch_len) {
po_w = po_r + 4;
/* DRM_DEBUG("batchbuffer does not end by MI_BATCH_BUFFER_END !\n"); */
} else {
po_w = po_r;
DRM_DEBUG("batchbuffer does not end by MI_BATCH_BUFFER_END, overwriting last bo cmd !\n");
}
*(uint32_t *)(mkva + po_w) = MI_BATCH_BUFFER_END;
}
pmap_unmapdev((vm_offset_t)mkva, 2 * PAGE_SIZE);
}
int i915_fix_mi_batchbuffer_end = 0;
static int
i915_reset_gen7_sol_offsets(struct drm_device *dev,
struct intel_ring_buffer *ring)
{
drm_i915_private_t *dev_priv = dev->dev_private;
int ret, i;
if (!IS_GEN7(dev) || ring != &dev_priv->rings[RCS])
return 0;
ret = intel_ring_begin(ring, 4 * 3);
if (ret)
return ret;
for (i = 0; i < 4; i++) {
intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
intel_ring_emit(ring, GEN7_SO_WRITE_OFFSET(i));
intel_ring_emit(ring, 0);
}
intel_ring_advance(ring);
return 0;
}
static int
i915_gem_do_execbuffer(struct drm_device *dev, void *data,
struct drm_file *file,
struct drm_i915_gem_execbuffer2 *args,
struct drm_i915_gem_exec_object2 *exec)
{
drm_i915_private_t *dev_priv = dev->dev_private;
struct list_head objects;
struct eb_objects *eb;
struct drm_i915_gem_object *batch_obj;
struct drm_clip_rect *cliprects = NULL;
struct intel_ring_buffer *ring;
u32 ctx_id = i915_execbuffer2_get_context_id(*args);
u32 exec_start, exec_len;
u32 seqno;
u32 mask;
int ret, mode, i;
vm_page_t **relocs_ma;
int *relocs_len;
if (!i915_gem_check_execbuffer(args)) {
DRM_DEBUG("execbuf with invalid offset/length\n");
return -EINVAL;
}
if (args->batch_len == 0)
return (0);
ret = validate_exec_list(exec, args->buffer_count,
&relocs_ma, &relocs_len);
if (ret)
goto pre_mutex_err;
switch (args->flags & I915_EXEC_RING_MASK) {
case I915_EXEC_DEFAULT:
case I915_EXEC_RENDER:
ring = &dev_priv->rings[RCS];
break;
case I915_EXEC_BSD:
ring = &dev_priv->rings[VCS];
if (ctx_id != 0) {
DRM_DEBUG("Ring %s doesn't support contexts\n",
ring->name);
ret = -EPERM;
goto pre_mutex_err;
}
break;
case I915_EXEC_BLT:
ring = &dev_priv->rings[BCS];
if (ctx_id != 0) {
DRM_DEBUG("Ring %s doesn't support contexts\n",
ring->name);
ret = -EPERM;
goto pre_mutex_err;
}
break;
default:
DRM_DEBUG("execbuf with unknown ring: %d\n",
(int)(args->flags & I915_EXEC_RING_MASK));
ret = -EINVAL;
goto pre_mutex_err;
}
if (!intel_ring_initialized(ring)) {
DRM_DEBUG("execbuf with invalid ring: %d\n",
(int)(args->flags & I915_EXEC_RING_MASK));
ret = -EINVAL;
goto pre_mutex_err;
}
mode = args->flags & I915_EXEC_CONSTANTS_MASK;
mask = I915_EXEC_CONSTANTS_MASK;
switch (mode) {
case I915_EXEC_CONSTANTS_REL_GENERAL:
case I915_EXEC_CONSTANTS_ABSOLUTE:
case I915_EXEC_CONSTANTS_REL_SURFACE:
if (ring == &dev_priv->rings[RCS] &&
mode != dev_priv->relative_constants_mode) {
if (INTEL_INFO(dev)->gen < 4) {
ret = -EINVAL;
goto pre_mutex_err;
}
if (INTEL_INFO(dev)->gen > 5 &&
mode == I915_EXEC_CONSTANTS_REL_SURFACE) {
ret = -EINVAL;
goto pre_mutex_err;
}
/* The HW changed the meaning on this bit on gen6 */
if (INTEL_INFO(dev)->gen >= 6)
mask &= ~I915_EXEC_CONSTANTS_REL_SURFACE;
}
break;
default:
DRM_DEBUG("execbuf with unknown constants: %d\n", mode);
ret = -EINVAL;
goto pre_mutex_err;
}
if (args->buffer_count < 1) {
DRM_DEBUG("execbuf with %d buffers\n", args->buffer_count);
ret = -EINVAL;
goto pre_mutex_err;
}
if (args->num_cliprects != 0) {
if (ring != &dev_priv->rings[RCS]) {
DRM_DEBUG("clip rectangles are only valid with the render ring\n");
ret = -EINVAL;
goto pre_mutex_err;
}
if (INTEL_INFO(dev)->gen >= 5) {
DRM_DEBUG("clip rectangles are only valid on pre-gen5\n");
ret = -EINVAL;
goto pre_mutex_err;
}
if (args->num_cliprects > UINT_MAX / sizeof(*cliprects)) {
DRM_DEBUG("execbuf with %u cliprects\n",
args->num_cliprects);
ret = -EINVAL;
goto pre_mutex_err;
}
cliprects = malloc(args->num_cliprects * sizeof(*cliprects),
DRM_I915_GEM, M_WAITOK | M_ZERO);
ret = -copyin((void *)(uintptr_t)args->cliprects_ptr, cliprects,
sizeof(*cliprects) * args->num_cliprects);
if (ret != 0)
goto pre_mutex_err;
}
ret = i915_mutex_lock_interruptible(dev);
if (ret)
goto pre_mutex_err;
if (dev_priv->mm.suspended) {
DRM_UNLOCK(dev);
ret = -EBUSY;
goto pre_mutex_err;
}
eb = eb_create(args->buffer_count);
if (eb == NULL) {
DRM_UNLOCK(dev);
ret = -ENOMEM;
goto pre_mutex_err;
}
/* Look up object handles */
INIT_LIST_HEAD(&objects);
for (i = 0; i < args->buffer_count; i++) {
struct drm_i915_gem_object *obj;
obj = to_intel_bo(drm_gem_object_lookup(dev, file,
exec[i].handle));
if (&obj->base == NULL) {
DRM_DEBUG("Invalid object handle %d at index %d\n",
exec[i].handle, i);
/* prevent error path from reading uninitialized data */
ret = -ENOENT;
goto err;
}
if (!list_empty(&obj->exec_list)) {
DRM_DEBUG("Object %p [handle %d, index %d] appears more than once in object list\n",
obj, exec[i].handle, i);
ret = -EINVAL;
goto err;
}
list_add_tail(&obj->exec_list, &objects);
obj->exec_handle = exec[i].handle;
obj->exec_entry = &exec[i];
eb_add_object(eb, obj);
}
/* take note of the batch buffer before we might reorder the lists */
batch_obj = list_entry(objects.prev,
struct drm_i915_gem_object,
exec_list);
/* Move the objects en-masse into the GTT, evicting if necessary. */
ret = i915_gem_execbuffer_reserve(ring, file, &objects);
if (ret)
goto err;
/* The objects are in their final locations, apply the relocations. */
ret = i915_gem_execbuffer_relocate(dev, eb, &objects);
if (ret) {
if (ret == -EFAULT) {
ret = i915_gem_execbuffer_relocate_slow(dev, file, ring,
&objects, eb,
exec,
args->buffer_count);
DRM_LOCK_ASSERT(dev);
}
if (ret)
goto err;
}
/* Set the pending read domains for the batch buffer to COMMAND */
if (batch_obj->base.pending_write_domain) {
DRM_DEBUG("Attempting to use self-modifying batch buffer\n");
ret = -EINVAL;
goto err;
}
batch_obj->base.pending_read_domains |= I915_GEM_DOMAIN_COMMAND;
ret = i915_gem_execbuffer_move_to_gpu(ring, &objects);
if (ret)
goto err;
ret = i915_switch_context(ring, file, ctx_id);
if (ret)
goto err;
seqno = i915_gem_next_request_seqno(ring);
for (i = 0; i < I915_NUM_RINGS - 1; i++) {
if (seqno < ring->sync_seqno[i]) {
/* The GPU can not handle its semaphore value wrapping,
* so every billion or so execbuffers, we need to stall
* the GPU in order to reset the counters.
*/
ret = i915_gpu_idle(dev);
if (ret)
goto err;
i915_gem_retire_requests(dev);
KASSERT(ring->sync_seqno[i] == 0, ("Non-zero sync_seqno"));
}
}
if (ring == &dev_priv->rings[RCS] &&
mode != dev_priv->relative_constants_mode) {
ret = intel_ring_begin(ring, 4);
if (ret)
goto err;
intel_ring_emit(ring, MI_NOOP);
intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
intel_ring_emit(ring, INSTPM);
intel_ring_emit(ring, mask << 16 | mode);
intel_ring_advance(ring);
dev_priv->relative_constants_mode = mode;
}
if (args->flags & I915_EXEC_GEN7_SOL_RESET) {
ret = i915_reset_gen7_sol_offsets(dev, ring);
if (ret)
goto err;
}
exec_start = batch_obj->gtt_offset + args->batch_start_offset;
exec_len = args->batch_len;
if (i915_fix_mi_batchbuffer_end) {
i915_gem_fix_mi_batchbuffer_end(batch_obj,
args->batch_start_offset, args->batch_len);
}
if (cliprects) {
for (i = 0; i < args->num_cliprects; i++) {
ret = i915_emit_box(dev, &cliprects[i],
args->DR1, args->DR4);
if (ret)
goto err;
ret = ring->dispatch_execbuffer(ring,
exec_start, exec_len);
if (ret)
goto err;
}
} else {
ret = ring->dispatch_execbuffer(ring,
exec_start, exec_len);
if (ret)
goto err;
}
CTR4(KTR_DRM, "ring_dispatch %s %d exec %x %x", ring->name, seqno,
exec_start, exec_len);
i915_gem_execbuffer_move_to_active(&objects, ring, seqno);
i915_gem_execbuffer_retire_commands(dev, file, ring);
err:
eb_destroy(eb);
while (!list_empty(&objects)) {
struct drm_i915_gem_object *obj;
obj = list_first_entry(&objects,
struct drm_i915_gem_object,
exec_list);
list_del_init(&obj->exec_list);
drm_gem_object_unreference(&obj->base);
}
DRM_UNLOCK(dev);
pre_mutex_err:
for (i = 0; i < args->buffer_count; i++) {
if (relocs_ma[i] != NULL) {
vm_page_unhold_pages(relocs_ma[i], relocs_len[i]);
free(relocs_ma[i], DRM_I915_GEM);
}
}
free(relocs_len, DRM_I915_GEM);
free(relocs_ma, DRM_I915_GEM);
free(cliprects, DRM_I915_GEM);
return ret;
}
/*
* Legacy execbuffer just creates an exec2 list from the original exec object
* list array and passes it to the real function.
*/
int
i915_gem_execbuffer(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_execbuffer *args = data;
struct drm_i915_gem_execbuffer2 exec2;
struct drm_i915_gem_exec_object *exec_list = NULL;
struct drm_i915_gem_exec_object2 *exec2_list = NULL;
int ret, i;
DRM_DEBUG("buffers_ptr %d buffer_count %d len %08x\n",
(int) args->buffers_ptr, args->buffer_count, args->batch_len);
if (args->buffer_count < 1) {
DRM_DEBUG("execbuf with %d buffers\n", args->buffer_count);
return -EINVAL;
}
/* Copy in the exec list from userland */
/* XXXKIB user-controlled malloc size */
exec_list = malloc(sizeof(*exec_list) * args->buffer_count,
DRM_I915_GEM, M_WAITOK);
exec2_list = malloc(sizeof(*exec2_list) * args->buffer_count,
DRM_I915_GEM, M_WAITOK);
ret = -copyin((void *)(uintptr_t)args->buffers_ptr, exec_list,
sizeof(*exec_list) * args->buffer_count);
if (ret != 0) {
DRM_DEBUG("copy %d exec entries failed %d\n",
args->buffer_count, ret);
free(exec_list, DRM_I915_GEM);
free(exec2_list, DRM_I915_GEM);
return ret;
}
for (i = 0; i < args->buffer_count; i++) {
exec2_list[i].handle = exec_list[i].handle;
exec2_list[i].relocation_count = exec_list[i].relocation_count;
exec2_list[i].relocs_ptr = exec_list[i].relocs_ptr;
exec2_list[i].alignment = exec_list[i].alignment;
exec2_list[i].offset = exec_list[i].offset;
if (INTEL_INFO(dev)->gen < 4)
exec2_list[i].flags = EXEC_OBJECT_NEEDS_FENCE;
else
exec2_list[i].flags = 0;
}
exec2.buffers_ptr = args->buffers_ptr;
exec2.buffer_count = args->buffer_count;
exec2.batch_start_offset = args->batch_start_offset;
exec2.batch_len = args->batch_len;
exec2.DR1 = args->DR1;
exec2.DR4 = args->DR4;
exec2.num_cliprects = args->num_cliprects;
exec2.cliprects_ptr = args->cliprects_ptr;
exec2.flags = I915_EXEC_RENDER;
i915_execbuffer2_set_context_id(exec2, 0);
ret = i915_gem_do_execbuffer(dev, data, file, &exec2, exec2_list);
if (!ret) {
/* Copy the new buffer offsets back to the user's exec list. */
for (i = 0; i < args->buffer_count; i++)
exec_list[i].offset = exec2_list[i].offset;
/* ... and back out to userspace */
ret = -copyout(exec_list, (void *)(uintptr_t)args->buffers_ptr,
sizeof(*exec_list) * args->buffer_count);
if (ret != 0) {
DRM_DEBUG("failed to copy %d exec entries "
"back to user (%d)\n",
args->buffer_count, ret);
}
}
free(exec_list, DRM_I915_GEM);
free(exec2_list, DRM_I915_GEM);
return ret;
}
int
i915_gem_execbuffer2(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_execbuffer2 *args = data;
struct drm_i915_gem_exec_object2 *exec2_list = NULL;
int ret;
DRM_DEBUG("buffers_ptr %jx buffer_count %d len %08x\n",
(uintmax_t)args->buffers_ptr, args->buffer_count, args->batch_len);
if (args->buffer_count < 1 ||
args->buffer_count > UINT_MAX / sizeof(*exec2_list)) {
DRM_DEBUG("execbuf2 with %d buffers\n", args->buffer_count);
return -EINVAL;
}
/* XXXKIB user-controllable malloc size */
exec2_list = malloc(sizeof(*exec2_list)*args->buffer_count,
DRM_I915_GEM, M_WAITOK);
ret = -copyin((void *)(uintptr_t)args->buffers_ptr, exec2_list,
sizeof(*exec2_list) * args->buffer_count);
if (ret != 0) {
DRM_DEBUG("copy %d exec entries failed %d\n",
args->buffer_count, ret);
free(exec2_list, DRM_I915_GEM);
return -EFAULT;
}
ret = i915_gem_do_execbuffer(dev, data, file, args, exec2_list);
if (!ret) {
/* Copy the new buffer offsets back to the user's exec list. */
ret = -copyout(exec2_list, (void *)(uintptr_t)args->buffers_ptr,
sizeof(*exec2_list) * args->buffer_count);
if (ret) {
DRM_DEBUG("failed to copy %d exec entries "
"back to user (%d)\n",
args->buffer_count, ret);
}
}
free(exec2_list, DRM_I915_GEM);
return ret;
}