alistair23-linux/drivers/gpu/drm/i915/i915_gem.c
Chris Wilson b2eadbc85b drm/i915: Lazily apply the SNB+ seqno w/a
Avoid the forcewake overhead when simply retiring requests, as often the
last seen seqno is good enough to satisfy the retirment process and will
be promptly re-run in any case. Only ensure that we force the coherent
seqno read when we are explicitly waiting upon a completion event to be
sure that none go missing, and also for when we are reporting seqno
values in case of error or debugging.

This greatly reduces the load for userspace using the busy-ioctl to
track active buffers, for instance halving the CPU used by X in pushing
the pixels from a software render (flash). The effect will be even more
magnified with userptr and so providing a zero-copy upload path in that
instance, or in similar instances where X is simply compositing DRI
buffers.

v2: Reverse the polarity of the tachyon stream. Daniel suggested that
'force' was too generic for the parameter name and that 'lazy_coherency'
better encapsulated the semantics of it being an optimization and its
purpose. Also notice that gen6_get_seqno() is only used by gen6/7
chipsets and so the test for IS_GEN6 || IS_GEN7 is redundant in that
function.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-08-10 11:11:32 +02:00

4283 lines
106 KiB
C

/*
* Copyright © 2008 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>
*
*/
#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"
#include "i915_trace.h"
#include "intel_drv.h"
#include <linux/shmem_fs.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/pci.h>
#include <linux/dma-buf.h>
static void i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj);
static void i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj);
static __must_check int i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
unsigned alignment,
bool map_and_fenceable);
static int i915_gem_phys_pwrite(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct drm_i915_gem_pwrite *args,
struct drm_file *file);
static void i915_gem_write_fence(struct drm_device *dev, int reg,
struct drm_i915_gem_object *obj);
static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
struct drm_i915_fence_reg *fence,
bool enable);
static int i915_gem_inactive_shrink(struct shrinker *shrinker,
struct shrink_control *sc);
static void i915_gem_object_truncate(struct drm_i915_gem_object *obj);
static inline void i915_gem_object_fence_lost(struct drm_i915_gem_object *obj)
{
if (obj->tiling_mode)
i915_gem_release_mmap(obj);
/* As we do not have an associated fence register, we will force
* a tiling change if we ever need to acquire one.
*/
obj->fence_dirty = false;
obj->fence_reg = I915_FENCE_REG_NONE;
}
/* some bookkeeping */
static void i915_gem_info_add_obj(struct drm_i915_private *dev_priv,
size_t size)
{
dev_priv->mm.object_count++;
dev_priv->mm.object_memory += size;
}
static void i915_gem_info_remove_obj(struct drm_i915_private *dev_priv,
size_t size)
{
dev_priv->mm.object_count--;
dev_priv->mm.object_memory -= size;
}
static int
i915_gem_wait_for_error(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct completion *x = &dev_priv->error_completion;
unsigned long flags;
int ret;
if (!atomic_read(&dev_priv->mm.wedged))
return 0;
/*
* Only wait 10 seconds for the gpu reset to complete to avoid hanging
* userspace. If it takes that long something really bad is going on and
* we should simply try to bail out and fail as gracefully as possible.
*/
ret = wait_for_completion_interruptible_timeout(x, 10*HZ);
if (ret == 0) {
DRM_ERROR("Timed out waiting for the gpu reset to complete\n");
return -EIO;
} else if (ret < 0) {
return ret;
}
if (atomic_read(&dev_priv->mm.wedged)) {
/* GPU is hung, bump the completion count to account for
* the token we just consumed so that we never hit zero and
* end up waiting upon a subsequent completion event that
* will never happen.
*/
spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
spin_unlock_irqrestore(&x->wait.lock, flags);
}
return 0;
}
int i915_mutex_lock_interruptible(struct drm_device *dev)
{
int ret;
ret = i915_gem_wait_for_error(dev);
if (ret)
return ret;
ret = mutex_lock_interruptible(&dev->struct_mutex);
if (ret)
return ret;
WARN_ON(i915_verify_lists(dev));
return 0;
}
static inline bool
i915_gem_object_is_inactive(struct drm_i915_gem_object *obj)
{
return !obj->active;
}
int
i915_gem_init_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_init *args = data;
if (drm_core_check_feature(dev, DRIVER_MODESET))
return -ENODEV;
if (args->gtt_start >= args->gtt_end ||
(args->gtt_end | args->gtt_start) & (PAGE_SIZE - 1))
return -EINVAL;
/* GEM with user mode setting was never supported on ilk and later. */
if (INTEL_INFO(dev)->gen >= 5)
return -ENODEV;
mutex_lock(&dev->struct_mutex);
i915_gem_init_global_gtt(dev, args->gtt_start,
args->gtt_end, args->gtt_end);
mutex_unlock(&dev->struct_mutex);
return 0;
}
int
i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_get_aperture *args = data;
struct drm_i915_gem_object *obj;
size_t pinned;
pinned = 0;
mutex_lock(&dev->struct_mutex);
list_for_each_entry(obj, &dev_priv->mm.gtt_list, gtt_list)
if (obj->pin_count)
pinned += obj->gtt_space->size;
mutex_unlock(&dev->struct_mutex);
args->aper_size = dev_priv->mm.gtt_total;
args->aper_available_size = args->aper_size - pinned;
return 0;
}
static int
i915_gem_create(struct drm_file *file,
struct drm_device *dev,
uint64_t size,
uint32_t *handle_p)
{
struct drm_i915_gem_object *obj;
int ret;
u32 handle;
size = roundup(size, PAGE_SIZE);
if (size == 0)
return -EINVAL;
/* Allocate the new object */
obj = i915_gem_alloc_object(dev, size);
if (obj == NULL)
return -ENOMEM;
ret = drm_gem_handle_create(file, &obj->base, &handle);
if (ret) {
drm_gem_object_release(&obj->base);
i915_gem_info_remove_obj(dev->dev_private, obj->base.size);
kfree(obj);
return ret;
}
/* drop reference from allocate - handle holds it now */
drm_gem_object_unreference(&obj->base);
trace_i915_gem_object_create(obj);
*handle_p = handle;
return 0;
}
int
i915_gem_dumb_create(struct drm_file *file,
struct drm_device *dev,
struct drm_mode_create_dumb *args)
{
/* have to work out size/pitch and return them */
args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
args->size = args->pitch * args->height;
return i915_gem_create(file, dev,
args->size, &args->handle);
}
int i915_gem_dumb_destroy(struct drm_file *file,
struct drm_device *dev,
uint32_t handle)
{
return drm_gem_handle_delete(file, handle);
}
/**
* Creates a new mm object and returns a handle to it.
*/
int
i915_gem_create_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_create *args = data;
return i915_gem_create(file, dev,
args->size, &args->handle);
}
static int i915_gem_object_needs_bit17_swizzle(struct drm_i915_gem_object *obj)
{
drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
return dev_priv->mm.bit_6_swizzle_x == I915_BIT_6_SWIZZLE_9_10_17 &&
obj->tiling_mode != I915_TILING_NONE;
}
static inline int
__copy_to_user_swizzled(char __user *cpu_vaddr,
const char *gpu_vaddr, int gpu_offset,
int length)
{
int ret, cpu_offset = 0;
while (length > 0) {
int cacheline_end = ALIGN(gpu_offset + 1, 64);
int this_length = min(cacheline_end - gpu_offset, length);
int swizzled_gpu_offset = gpu_offset ^ 64;
ret = __copy_to_user(cpu_vaddr + cpu_offset,
gpu_vaddr + swizzled_gpu_offset,
this_length);
if (ret)
return ret + length;
cpu_offset += this_length;
gpu_offset += this_length;
length -= this_length;
}
return 0;
}
static inline int
__copy_from_user_swizzled(char *gpu_vaddr, int gpu_offset,
const char __user *cpu_vaddr,
int length)
{
int ret, cpu_offset = 0;
while (length > 0) {
int cacheline_end = ALIGN(gpu_offset + 1, 64);
int this_length = min(cacheline_end - gpu_offset, length);
int swizzled_gpu_offset = gpu_offset ^ 64;
ret = __copy_from_user(gpu_vaddr + swizzled_gpu_offset,
cpu_vaddr + cpu_offset,
this_length);
if (ret)
return ret + length;
cpu_offset += this_length;
gpu_offset += this_length;
length -= this_length;
}
return 0;
}
/* Per-page copy function for the shmem pread fastpath.
* Flushes invalid cachelines before reading the target if
* needs_clflush is set. */
static int
shmem_pread_fast(struct page *page, int shmem_page_offset, int page_length,
char __user *user_data,
bool page_do_bit17_swizzling, bool needs_clflush)
{
char *vaddr;
int ret;
if (unlikely(page_do_bit17_swizzling))
return -EINVAL;
vaddr = kmap_atomic(page);
if (needs_clflush)
drm_clflush_virt_range(vaddr + shmem_page_offset,
page_length);
ret = __copy_to_user_inatomic(user_data,
vaddr + shmem_page_offset,
page_length);
kunmap_atomic(vaddr);
return ret;
}
static void
shmem_clflush_swizzled_range(char *addr, unsigned long length,
bool swizzled)
{
if (unlikely(swizzled)) {
unsigned long start = (unsigned long) addr;
unsigned long end = (unsigned long) addr + length;
/* For swizzling simply ensure that we always flush both
* channels. Lame, but simple and it works. Swizzled
* pwrite/pread is far from a hotpath - current userspace
* doesn't use it at all. */
start = round_down(start, 128);
end = round_up(end, 128);
drm_clflush_virt_range((void *)start, end - start);
} else {
drm_clflush_virt_range(addr, length);
}
}
/* Only difference to the fast-path function is that this can handle bit17
* and uses non-atomic copy and kmap functions. */
static int
shmem_pread_slow(struct page *page, int shmem_page_offset, int page_length,
char __user *user_data,
bool page_do_bit17_swizzling, bool needs_clflush)
{
char *vaddr;
int ret;
vaddr = kmap(page);
if (needs_clflush)
shmem_clflush_swizzled_range(vaddr + shmem_page_offset,
page_length,
page_do_bit17_swizzling);
if (page_do_bit17_swizzling)
ret = __copy_to_user_swizzled(user_data,
vaddr, shmem_page_offset,
page_length);
else
ret = __copy_to_user(user_data,
vaddr + shmem_page_offset,
page_length);
kunmap(page);
return ret;
}
static int
i915_gem_shmem_pread(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct drm_i915_gem_pread *args,
struct drm_file *file)
{
struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
char __user *user_data;
ssize_t remain;
loff_t offset;
int shmem_page_offset, page_length, ret = 0;
int obj_do_bit17_swizzling, page_do_bit17_swizzling;
int hit_slowpath = 0;
int prefaulted = 0;
int needs_clflush = 0;
int release_page;
user_data = (char __user *) (uintptr_t) args->data_ptr;
remain = args->size;
obj_do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj);
if (!(obj->base.read_domains & I915_GEM_DOMAIN_CPU)) {
/* If we're not in the cpu read domain, set ourself into the gtt
* read domain and manually flush cachelines (if required). This
* optimizes for the case when the gpu will dirty the data
* anyway again before the next pread happens. */
if (obj->cache_level == I915_CACHE_NONE)
needs_clflush = 1;
ret = i915_gem_object_set_to_gtt_domain(obj, false);
if (ret)
return ret;
}
offset = args->offset;
while (remain > 0) {
struct page *page;
/* Operation in this page
*
* shmem_page_offset = offset within page in shmem file
* page_length = bytes to copy for this page
*/
shmem_page_offset = offset_in_page(offset);
page_length = remain;
if ((shmem_page_offset + page_length) > PAGE_SIZE)
page_length = PAGE_SIZE - shmem_page_offset;
if (obj->pages) {
page = obj->pages[offset >> PAGE_SHIFT];
release_page = 0;
} else {
page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT);
if (IS_ERR(page)) {
ret = PTR_ERR(page);
goto out;
}
release_page = 1;
}
page_do_bit17_swizzling = obj_do_bit17_swizzling &&
(page_to_phys(page) & (1 << 17)) != 0;
ret = shmem_pread_fast(page, shmem_page_offset, page_length,
user_data, page_do_bit17_swizzling,
needs_clflush);
if (ret == 0)
goto next_page;
hit_slowpath = 1;
page_cache_get(page);
mutex_unlock(&dev->struct_mutex);
if (!prefaulted) {
ret = fault_in_multipages_writeable(user_data, remain);
/* Userspace is tricking us, but we've already clobbered
* its pages with the prefault and promised to write the
* data up to the first fault. Hence ignore any errors
* and just continue. */
(void)ret;
prefaulted = 1;
}
ret = shmem_pread_slow(page, shmem_page_offset, page_length,
user_data, page_do_bit17_swizzling,
needs_clflush);
mutex_lock(&dev->struct_mutex);
page_cache_release(page);
next_page:
mark_page_accessed(page);
if (release_page)
page_cache_release(page);
if (ret) {
ret = -EFAULT;
goto out;
}
remain -= page_length;
user_data += page_length;
offset += page_length;
}
out:
if (hit_slowpath) {
/* Fixup: Kill any reinstated backing storage pages */
if (obj->madv == __I915_MADV_PURGED)
i915_gem_object_truncate(obj);
}
return ret;
}
/**
* Reads data from the object referenced by handle.
*
* On error, the contents of *data are undefined.
*/
int
i915_gem_pread_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_pread *args = data;
struct drm_i915_gem_object *obj;
int ret = 0;
if (args->size == 0)
return 0;
if (!access_ok(VERIFY_WRITE,
(char __user *)(uintptr_t)args->data_ptr,
args->size))
return -EFAULT;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
/* Bounds check source. */
if (args->offset > obj->base.size ||
args->size > obj->base.size - args->offset) {
ret = -EINVAL;
goto out;
}
/* prime objects have no backing filp to GEM pread/pwrite
* pages from.
*/
if (!obj->base.filp) {
ret = -EINVAL;
goto out;
}
trace_i915_gem_object_pread(obj, args->offset, args->size);
ret = i915_gem_shmem_pread(dev, obj, args, file);
out:
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
/* This is the fast write path which cannot handle
* page faults in the source data
*/
static inline int
fast_user_write(struct io_mapping *mapping,
loff_t page_base, int page_offset,
char __user *user_data,
int length)
{
void __iomem *vaddr_atomic;
void *vaddr;
unsigned long unwritten;
vaddr_atomic = io_mapping_map_atomic_wc(mapping, page_base);
/* We can use the cpu mem copy function because this is X86. */
vaddr = (void __force*)vaddr_atomic + page_offset;
unwritten = __copy_from_user_inatomic_nocache(vaddr,
user_data, length);
io_mapping_unmap_atomic(vaddr_atomic);
return unwritten;
}
/**
* This is the fast pwrite path, where we copy the data directly from the
* user into the GTT, uncached.
*/
static int
i915_gem_gtt_pwrite_fast(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct drm_i915_gem_pwrite *args,
struct drm_file *file)
{
drm_i915_private_t *dev_priv = dev->dev_private;
ssize_t remain;
loff_t offset, page_base;
char __user *user_data;
int page_offset, page_length, ret;
ret = i915_gem_object_pin(obj, 0, true);
if (ret)
goto out;
ret = i915_gem_object_set_to_gtt_domain(obj, true);
if (ret)
goto out_unpin;
ret = i915_gem_object_put_fence(obj);
if (ret)
goto out_unpin;
user_data = (char __user *) (uintptr_t) args->data_ptr;
remain = args->size;
offset = obj->gtt_offset + args->offset;
while (remain > 0) {
/* Operation in this page
*
* page_base = page offset within aperture
* page_offset = offset within page
* page_length = bytes to copy for this page
*/
page_base = offset & PAGE_MASK;
page_offset = offset_in_page(offset);
page_length = remain;
if ((page_offset + remain) > PAGE_SIZE)
page_length = PAGE_SIZE - page_offset;
/* If we get a fault while copying data, then (presumably) our
* source page isn't available. Return the error and we'll
* retry in the slow path.
*/
if (fast_user_write(dev_priv->mm.gtt_mapping, page_base,
page_offset, user_data, page_length)) {
ret = -EFAULT;
goto out_unpin;
}
remain -= page_length;
user_data += page_length;
offset += page_length;
}
out_unpin:
i915_gem_object_unpin(obj);
out:
return ret;
}
/* Per-page copy function for the shmem pwrite fastpath.
* Flushes invalid cachelines before writing to the target if
* needs_clflush_before is set and flushes out any written cachelines after
* writing if needs_clflush is set. */
static int
shmem_pwrite_fast(struct page *page, int shmem_page_offset, int page_length,
char __user *user_data,
bool page_do_bit17_swizzling,
bool needs_clflush_before,
bool needs_clflush_after)
{
char *vaddr;
int ret;
if (unlikely(page_do_bit17_swizzling))
return -EINVAL;
vaddr = kmap_atomic(page);
if (needs_clflush_before)
drm_clflush_virt_range(vaddr + shmem_page_offset,
page_length);
ret = __copy_from_user_inatomic_nocache(vaddr + shmem_page_offset,
user_data,
page_length);
if (needs_clflush_after)
drm_clflush_virt_range(vaddr + shmem_page_offset,
page_length);
kunmap_atomic(vaddr);
return ret;
}
/* Only difference to the fast-path function is that this can handle bit17
* and uses non-atomic copy and kmap functions. */
static int
shmem_pwrite_slow(struct page *page, int shmem_page_offset, int page_length,
char __user *user_data,
bool page_do_bit17_swizzling,
bool needs_clflush_before,
bool needs_clflush_after)
{
char *vaddr;
int ret;
vaddr = kmap(page);
if (unlikely(needs_clflush_before || page_do_bit17_swizzling))
shmem_clflush_swizzled_range(vaddr + shmem_page_offset,
page_length,
page_do_bit17_swizzling);
if (page_do_bit17_swizzling)
ret = __copy_from_user_swizzled(vaddr, shmem_page_offset,
user_data,
page_length);
else
ret = __copy_from_user(vaddr + shmem_page_offset,
user_data,
page_length);
if (needs_clflush_after)
shmem_clflush_swizzled_range(vaddr + shmem_page_offset,
page_length,
page_do_bit17_swizzling);
kunmap(page);
return ret;
}
static int
i915_gem_shmem_pwrite(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct drm_i915_gem_pwrite *args,
struct drm_file *file)
{
struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
ssize_t remain;
loff_t offset;
char __user *user_data;
int shmem_page_offset, page_length, ret = 0;
int obj_do_bit17_swizzling, page_do_bit17_swizzling;
int hit_slowpath = 0;
int needs_clflush_after = 0;
int needs_clflush_before = 0;
int release_page;
user_data = (char __user *) (uintptr_t) args->data_ptr;
remain = args->size;
obj_do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj);
if (obj->base.write_domain != I915_GEM_DOMAIN_CPU) {
/* If we're not in the cpu write domain, set ourself into the gtt
* write domain and manually flush cachelines (if required). This
* optimizes for the case when the gpu will use the data
* right away and we therefore have to clflush anyway. */
if (obj->cache_level == I915_CACHE_NONE)
needs_clflush_after = 1;
ret = i915_gem_object_set_to_gtt_domain(obj, true);
if (ret)
return ret;
}
/* Same trick applies for invalidate partially written cachelines before
* writing. */
if (!(obj->base.read_domains & I915_GEM_DOMAIN_CPU)
&& obj->cache_level == I915_CACHE_NONE)
needs_clflush_before = 1;
offset = args->offset;
obj->dirty = 1;
while (remain > 0) {
struct page *page;
int partial_cacheline_write;
/* Operation in this page
*
* shmem_page_offset = offset within page in shmem file
* page_length = bytes to copy for this page
*/
shmem_page_offset = offset_in_page(offset);
page_length = remain;
if ((shmem_page_offset + page_length) > PAGE_SIZE)
page_length = PAGE_SIZE - shmem_page_offset;
/* If we don't overwrite a cacheline completely we need to be
* careful to have up-to-date data by first clflushing. Don't
* overcomplicate things and flush the entire patch. */
partial_cacheline_write = needs_clflush_before &&
((shmem_page_offset | page_length)
& (boot_cpu_data.x86_clflush_size - 1));
if (obj->pages) {
page = obj->pages[offset >> PAGE_SHIFT];
release_page = 0;
} else {
page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT);
if (IS_ERR(page)) {
ret = PTR_ERR(page);
goto out;
}
release_page = 1;
}
page_do_bit17_swizzling = obj_do_bit17_swizzling &&
(page_to_phys(page) & (1 << 17)) != 0;
ret = shmem_pwrite_fast(page, shmem_page_offset, page_length,
user_data, page_do_bit17_swizzling,
partial_cacheline_write,
needs_clflush_after);
if (ret == 0)
goto next_page;
hit_slowpath = 1;
page_cache_get(page);
mutex_unlock(&dev->struct_mutex);
ret = shmem_pwrite_slow(page, shmem_page_offset, page_length,
user_data, page_do_bit17_swizzling,
partial_cacheline_write,
needs_clflush_after);
mutex_lock(&dev->struct_mutex);
page_cache_release(page);
next_page:
set_page_dirty(page);
mark_page_accessed(page);
if (release_page)
page_cache_release(page);
if (ret) {
ret = -EFAULT;
goto out;
}
remain -= page_length;
user_data += page_length;
offset += page_length;
}
out:
if (hit_slowpath) {
/* Fixup: Kill any reinstated backing storage pages */
if (obj->madv == __I915_MADV_PURGED)
i915_gem_object_truncate(obj);
/* and flush dirty cachelines in case the object isn't in the cpu write
* domain anymore. */
if (obj->base.write_domain != I915_GEM_DOMAIN_CPU) {
i915_gem_clflush_object(obj);
intel_gtt_chipset_flush();
}
}
if (needs_clflush_after)
intel_gtt_chipset_flush();
return ret;
}
/**
* Writes data to the object referenced by handle.
*
* On error, the contents of the buffer that were to be modified are undefined.
*/
int
i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_pwrite *args = data;
struct drm_i915_gem_object *obj;
int ret;
if (args->size == 0)
return 0;
if (!access_ok(VERIFY_READ,
(char __user *)(uintptr_t)args->data_ptr,
args->size))
return -EFAULT;
ret = fault_in_multipages_readable((char __user *)(uintptr_t)args->data_ptr,
args->size);
if (ret)
return -EFAULT;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
/* Bounds check destination. */
if (args->offset > obj->base.size ||
args->size > obj->base.size - args->offset) {
ret = -EINVAL;
goto out;
}
/* prime objects have no backing filp to GEM pread/pwrite
* pages from.
*/
if (!obj->base.filp) {
ret = -EINVAL;
goto out;
}
trace_i915_gem_object_pwrite(obj, args->offset, args->size);
ret = -EFAULT;
/* We can only do the GTT pwrite on untiled buffers, as otherwise
* it would end up going through the fenced access, and we'll get
* different detiling behavior between reading and writing.
* pread/pwrite currently are reading and writing from the CPU
* perspective, requiring manual detiling by the client.
*/
if (obj->phys_obj) {
ret = i915_gem_phys_pwrite(dev, obj, args, file);
goto out;
}
if (obj->gtt_space &&
obj->cache_level == I915_CACHE_NONE &&
obj->tiling_mode == I915_TILING_NONE &&
obj->map_and_fenceable &&
obj->base.write_domain != I915_GEM_DOMAIN_CPU) {
ret = i915_gem_gtt_pwrite_fast(dev, obj, args, file);
/* Note that the gtt paths might fail with non-page-backed user
* pointers (e.g. gtt mappings when moving data between
* textures). Fallback to the shmem path in that case. */
}
if (ret == -EFAULT)
ret = i915_gem_shmem_pwrite(dev, obj, args, file);
out:
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
/**
* Called when user space prepares to use an object with the CPU, either
* through the mmap ioctl's mapping or a GTT mapping.
*/
int
i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_set_domain *args = data;
struct drm_i915_gem_object *obj;
uint32_t read_domains = args->read_domains;
uint32_t write_domain = args->write_domain;
int ret;
/* Only handle setting domains to types used by the CPU. */
if (write_domain & I915_GEM_GPU_DOMAINS)
return -EINVAL;
if (read_domains & I915_GEM_GPU_DOMAINS)
return -EINVAL;
/* Having something in the write domain implies it's in the read
* domain, and only that read domain. Enforce that in the request.
*/
if (write_domain != 0 && read_domains != write_domain)
return -EINVAL;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
if (read_domains & I915_GEM_DOMAIN_GTT) {
ret = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0);
/* Silently promote "you're not bound, there was nothing to do"
* to success, since the client was just asking us to
* make sure everything was done.
*/
if (ret == -EINVAL)
ret = 0;
} else {
ret = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0);
}
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
/**
* Called when user space has done writes to this buffer
*/
int
i915_gem_sw_finish_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_sw_finish *args = data;
struct drm_i915_gem_object *obj;
int ret = 0;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
/* Pinned buffers may be scanout, so flush the cache */
if (obj->pin_count)
i915_gem_object_flush_cpu_write_domain(obj);
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
/**
* Maps the contents of an object, returning the address it is mapped
* into.
*
* While the mapping holds a reference on the contents of the object, it doesn't
* imply a ref on the object itself.
*/
int
i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_mmap *args = data;
struct drm_gem_object *obj;
unsigned long addr;
obj = drm_gem_object_lookup(dev, file, args->handle);
if (obj == NULL)
return -ENOENT;
/* prime objects have no backing filp to GEM mmap
* pages from.
*/
if (!obj->filp) {
drm_gem_object_unreference_unlocked(obj);
return -EINVAL;
}
addr = vm_mmap(obj->filp, 0, args->size,
PROT_READ | PROT_WRITE, MAP_SHARED,
args->offset);
drm_gem_object_unreference_unlocked(obj);
if (IS_ERR((void *)addr))
return addr;
args->addr_ptr = (uint64_t) addr;
return 0;
}
/**
* i915_gem_fault - fault a page into the GTT
* vma: VMA in question
* vmf: fault info
*
* The fault handler is set up by drm_gem_mmap() when a object is GTT mapped
* from userspace. The fault handler takes care of binding the object to
* the GTT (if needed), allocating and programming a fence register (again,
* only if needed based on whether the old reg is still valid or the object
* is tiled) and inserting a new PTE into the faulting process.
*
* Note that the faulting process may involve evicting existing objects
* from the GTT and/or fence registers to make room. So performance may
* suffer if the GTT working set is large or there are few fence registers
* left.
*/
int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct drm_i915_gem_object *obj = to_intel_bo(vma->vm_private_data);
struct drm_device *dev = obj->base.dev;
drm_i915_private_t *dev_priv = dev->dev_private;
pgoff_t page_offset;
unsigned long pfn;
int ret = 0;
bool write = !!(vmf->flags & FAULT_FLAG_WRITE);
/* We don't use vmf->pgoff since that has the fake offset */
page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
PAGE_SHIFT;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
goto out;
trace_i915_gem_object_fault(obj, page_offset, true, write);
/* Now bind it into the GTT if needed */
if (!obj->map_and_fenceable) {
ret = i915_gem_object_unbind(obj);
if (ret)
goto unlock;
}
if (!obj->gtt_space) {
ret = i915_gem_object_bind_to_gtt(obj, 0, true);
if (ret)
goto unlock;
ret = i915_gem_object_set_to_gtt_domain(obj, write);
if (ret)
goto unlock;
}
if (!obj->has_global_gtt_mapping)
i915_gem_gtt_bind_object(obj, obj->cache_level);
ret = i915_gem_object_get_fence(obj);
if (ret)
goto unlock;
if (i915_gem_object_is_inactive(obj))
list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
obj->fault_mappable = true;
pfn = ((dev_priv->mm.gtt_base_addr + obj->gtt_offset) >> PAGE_SHIFT) +
page_offset;
/* Finally, remap it using the new GTT offset */
ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
unlock:
mutex_unlock(&dev->struct_mutex);
out:
switch (ret) {
case -EIO:
/* If this -EIO is due to a gpu hang, give the reset code a
* chance to clean up the mess. Otherwise return the proper
* SIGBUS. */
if (!atomic_read(&dev_priv->mm.wedged))
return VM_FAULT_SIGBUS;
case -EAGAIN:
/* Give the error handler a chance to run and move the
* objects off the GPU active list. Next time we service the
* fault, we should be able to transition the page into the
* GTT without touching the GPU (and so avoid further
* EIO/EGAIN). If the GPU is wedged, then there is no issue
* with coherency, just lost writes.
*/
set_need_resched();
case 0:
case -ERESTARTSYS:
case -EINTR:
return VM_FAULT_NOPAGE;
case -ENOMEM:
return VM_FAULT_OOM;
default:
return VM_FAULT_SIGBUS;
}
}
/**
* i915_gem_release_mmap - remove physical page mappings
* @obj: obj in question
*
* Preserve the reservation of the mmapping with the DRM core code, but
* relinquish ownership of the pages back to the system.
*
* It is vital that we remove the page mapping if we have mapped a tiled
* object through the GTT and then lose the fence register due to
* resource pressure. Similarly if the object has been moved out of the
* aperture, than pages mapped into userspace must be revoked. Removing the
* mapping will then trigger a page fault on the next user access, allowing
* fixup by i915_gem_fault().
*/
void
i915_gem_release_mmap(struct drm_i915_gem_object *obj)
{
if (!obj->fault_mappable)
return;
if (obj->base.dev->dev_mapping)
unmap_mapping_range(obj->base.dev->dev_mapping,
(loff_t)obj->base.map_list.hash.key<<PAGE_SHIFT,
obj->base.size, 1);
obj->fault_mappable = false;
}
static uint32_t
i915_gem_get_gtt_size(struct drm_device *dev, uint32_t size, int tiling_mode)
{
uint32_t gtt_size;
if (INTEL_INFO(dev)->gen >= 4 ||
tiling_mode == I915_TILING_NONE)
return size;
/* Previous chips need a power-of-two fence region when tiling */
if (INTEL_INFO(dev)->gen == 3)
gtt_size = 1024*1024;
else
gtt_size = 512*1024;
while (gtt_size < size)
gtt_size <<= 1;
return gtt_size;
}
/**
* i915_gem_get_gtt_alignment - return required GTT alignment for an object
* @obj: object to check
*
* Return the required GTT alignment for an object, taking into account
* potential fence register mapping.
*/
static uint32_t
i915_gem_get_gtt_alignment(struct drm_device *dev,
uint32_t size,
int tiling_mode)
{
/*
* Minimum alignment is 4k (GTT page size), but might be greater
* if a fence register is needed for the object.
*/
if (INTEL_INFO(dev)->gen >= 4 ||
tiling_mode == I915_TILING_NONE)
return 4096;
/*
* Previous chips need to be aligned to the size of the smallest
* fence register that can contain the object.
*/
return i915_gem_get_gtt_size(dev, size, tiling_mode);
}
/**
* i915_gem_get_unfenced_gtt_alignment - return required GTT alignment for an
* unfenced object
* @dev: the device
* @size: size of the object
* @tiling_mode: tiling mode of the object
*
* Return the required GTT alignment for an object, only taking into account
* unfenced tiled surface requirements.
*/
uint32_t
i915_gem_get_unfenced_gtt_alignment(struct drm_device *dev,
uint32_t size,
int tiling_mode)
{
/*
* Minimum alignment is 4k (GTT page size) for sane hw.
*/
if (INTEL_INFO(dev)->gen >= 4 || IS_G33(dev) ||
tiling_mode == I915_TILING_NONE)
return 4096;
/* Previous hardware however needs to be aligned to a power-of-two
* tile height. The simplest method for determining this is to reuse
* the power-of-tile object size.
*/
return i915_gem_get_gtt_size(dev, size, tiling_mode);
}
int
i915_gem_mmap_gtt(struct drm_file *file,
struct drm_device *dev,
uint32_t handle,
uint64_t *offset)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_object *obj;
int ret;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
if (obj->base.size > dev_priv->mm.gtt_mappable_end) {
ret = -E2BIG;
goto out;
}
if (obj->madv != I915_MADV_WILLNEED) {
DRM_ERROR("Attempting to mmap a purgeable buffer\n");
ret = -EINVAL;
goto out;
}
if (!obj->base.map_list.map) {
ret = drm_gem_create_mmap_offset(&obj->base);
if (ret)
goto out;
}
*offset = (u64)obj->base.map_list.hash.key << PAGE_SHIFT;
out:
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
/**
* i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
* @dev: DRM device
* @data: GTT mapping ioctl data
* @file: GEM object info
*
* Simply returns the fake offset to userspace so it can mmap it.
* The mmap call will end up in drm_gem_mmap(), which will set things
* up so we can get faults in the handler above.
*
* The fault handler will take care of binding the object into the GTT
* (since it may have been evicted to make room for something), allocating
* a fence register, and mapping the appropriate aperture address into
* userspace.
*/
int
i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_mmap_gtt *args = data;
return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);
}
int
i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj,
gfp_t gfpmask)
{
int page_count, i;
struct address_space *mapping;
struct inode *inode;
struct page *page;
if (obj->pages || obj->sg_table)
return 0;
/* Get the list of pages out of our struct file. They'll be pinned
* at this point until we release them.
*/
page_count = obj->base.size / PAGE_SIZE;
BUG_ON(obj->pages != NULL);
obj->pages = drm_malloc_ab(page_count, sizeof(struct page *));
if (obj->pages == NULL)
return -ENOMEM;
inode = obj->base.filp->f_path.dentry->d_inode;
mapping = inode->i_mapping;
gfpmask |= mapping_gfp_mask(mapping);
for (i = 0; i < page_count; i++) {
page = shmem_read_mapping_page_gfp(mapping, i, gfpmask);
if (IS_ERR(page))
goto err_pages;
obj->pages[i] = page;
}
if (i915_gem_object_needs_bit17_swizzle(obj))
i915_gem_object_do_bit_17_swizzle(obj);
return 0;
err_pages:
while (i--)
page_cache_release(obj->pages[i]);
drm_free_large(obj->pages);
obj->pages = NULL;
return PTR_ERR(page);
}
static void
i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
{
int page_count = obj->base.size / PAGE_SIZE;
int i;
if (!obj->pages)
return;
BUG_ON(obj->madv == __I915_MADV_PURGED);
if (i915_gem_object_needs_bit17_swizzle(obj))
i915_gem_object_save_bit_17_swizzle(obj);
if (obj->madv == I915_MADV_DONTNEED)
obj->dirty = 0;
for (i = 0; i < page_count; i++) {
if (obj->dirty)
set_page_dirty(obj->pages[i]);
if (obj->madv == I915_MADV_WILLNEED)
mark_page_accessed(obj->pages[i]);
page_cache_release(obj->pages[i]);
}
obj->dirty = 0;
drm_free_large(obj->pages);
obj->pages = NULL;
}
void
i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
struct intel_ring_buffer *ring,
u32 seqno)
{
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
BUG_ON(ring == NULL);
obj->ring = ring;
/* Add a reference if we're newly entering the active list. */
if (!obj->active) {
drm_gem_object_reference(&obj->base);
obj->active = 1;
}
/* Move from whatever list we were on to the tail of execution. */
list_move_tail(&obj->mm_list, &dev_priv->mm.active_list);
list_move_tail(&obj->ring_list, &ring->active_list);
obj->last_read_seqno = seqno;
if (obj->fenced_gpu_access) {
obj->last_fenced_seqno = seqno;
/* Bump MRU to take account of the delayed flush */
if (obj->fence_reg != I915_FENCE_REG_NONE) {
struct drm_i915_fence_reg *reg;
reg = &dev_priv->fence_regs[obj->fence_reg];
list_move_tail(&reg->lru_list,
&dev_priv->mm.fence_list);
}
}
}
static void
i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
{
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
BUG_ON(obj->base.write_domain & ~I915_GEM_GPU_DOMAINS);
BUG_ON(!obj->active);
if (obj->pin_count) /* are we a framebuffer? */
intel_mark_fb_idle(obj);
list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
list_del_init(&obj->ring_list);
obj->ring = NULL;
obj->last_read_seqno = 0;
obj->last_write_seqno = 0;
obj->base.write_domain = 0;
obj->last_fenced_seqno = 0;
obj->fenced_gpu_access = false;
obj->active = 0;
drm_gem_object_unreference(&obj->base);
WARN_ON(i915_verify_lists(dev));
}
/* Immediately discard the backing storage */
static void
i915_gem_object_truncate(struct drm_i915_gem_object *obj)
{
struct inode *inode;
/* Our goal here is to return as much of the memory as
* is possible back to the system as we are called from OOM.
* To do this we must instruct the shmfs to drop all of its
* backing pages, *now*.
*/
inode = obj->base.filp->f_path.dentry->d_inode;
shmem_truncate_range(inode, 0, (loff_t)-1);
if (obj->base.map_list.map)
drm_gem_free_mmap_offset(&obj->base);
obj->madv = __I915_MADV_PURGED;
}
static inline int
i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj)
{
return obj->madv == I915_MADV_DONTNEED;
}
static u32
i915_gem_get_seqno(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
u32 seqno = dev_priv->next_seqno;
/* reserve 0 for non-seqno */
if (++dev_priv->next_seqno == 0)
dev_priv->next_seqno = 1;
return seqno;
}
u32
i915_gem_next_request_seqno(struct intel_ring_buffer *ring)
{
if (ring->outstanding_lazy_request == 0)
ring->outstanding_lazy_request = i915_gem_get_seqno(ring->dev);
return ring->outstanding_lazy_request;
}
int
i915_add_request(struct intel_ring_buffer *ring,
struct drm_file *file,
struct drm_i915_gem_request *request)
{
drm_i915_private_t *dev_priv = ring->dev->dev_private;
uint32_t seqno;
u32 request_ring_position;
int was_empty;
int ret;
/*
* Emit any outstanding flushes - execbuf can fail to emit the flush
* after having emitted the batchbuffer command. Hence we need to fix
* things up similar to emitting the lazy request. The difference here
* is that the flush _must_ happen before the next request, no matter
* what.
*/
ret = intel_ring_flush_all_caches(ring);
if (ret)
return ret;
if (request == NULL) {
request = kmalloc(sizeof(*request), GFP_KERNEL);
if (request == NULL)
return -ENOMEM;
}
seqno = i915_gem_next_request_seqno(ring);
/* Record the position of the start of the request so that
* should we detect the updated seqno part-way through the
* GPU processing the request, we never over-estimate the
* position of the head.
*/
request_ring_position = intel_ring_get_tail(ring);
ret = ring->add_request(ring, &seqno);
if (ret) {
kfree(request);
return ret;
}
trace_i915_gem_request_add(ring, seqno);
request->seqno = seqno;
request->ring = ring;
request->tail = request_ring_position;
request->emitted_jiffies = jiffies;
was_empty = list_empty(&ring->request_list);
list_add_tail(&request->list, &ring->request_list);
request->file_priv = NULL;
if (file) {
struct drm_i915_file_private *file_priv = file->driver_priv;
spin_lock(&file_priv->mm.lock);
request->file_priv = file_priv;
list_add_tail(&request->client_list,
&file_priv->mm.request_list);
spin_unlock(&file_priv->mm.lock);
}
ring->outstanding_lazy_request = 0;
if (!dev_priv->mm.suspended) {
if (i915_enable_hangcheck) {
mod_timer(&dev_priv->hangcheck_timer,
jiffies +
msecs_to_jiffies(DRM_I915_HANGCHECK_PERIOD));
}
if (was_empty) {
queue_delayed_work(dev_priv->wq,
&dev_priv->mm.retire_work, HZ);
intel_mark_busy(dev_priv->dev);
}
}
return 0;
}
static inline void
i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
{
struct drm_i915_file_private *file_priv = request->file_priv;
if (!file_priv)
return;
spin_lock(&file_priv->mm.lock);
if (request->file_priv) {
list_del(&request->client_list);
request->file_priv = NULL;
}
spin_unlock(&file_priv->mm.lock);
}
static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
struct intel_ring_buffer *ring)
{
while (!list_empty(&ring->request_list)) {
struct drm_i915_gem_request *request;
request = list_first_entry(&ring->request_list,
struct drm_i915_gem_request,
list);
list_del(&request->list);
i915_gem_request_remove_from_client(request);
kfree(request);
}
while (!list_empty(&ring->active_list)) {
struct drm_i915_gem_object *obj;
obj = list_first_entry(&ring->active_list,
struct drm_i915_gem_object,
ring_list);
i915_gem_object_move_to_inactive(obj);
}
}
static void i915_gem_reset_fences(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
int i;
for (i = 0; i < dev_priv->num_fence_regs; i++) {
struct drm_i915_fence_reg *reg = &dev_priv->fence_regs[i];
i915_gem_write_fence(dev, i, NULL);
if (reg->obj)
i915_gem_object_fence_lost(reg->obj);
reg->pin_count = 0;
reg->obj = NULL;
INIT_LIST_HEAD(&reg->lru_list);
}
INIT_LIST_HEAD(&dev_priv->mm.fence_list);
}
void i915_gem_reset(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_object *obj;
struct intel_ring_buffer *ring;
int i;
for_each_ring(ring, dev_priv, i)
i915_gem_reset_ring_lists(dev_priv, ring);
/* Move everything out of the GPU domains to ensure we do any
* necessary invalidation upon reuse.
*/
list_for_each_entry(obj,
&dev_priv->mm.inactive_list,
mm_list)
{
obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
}
/* The fence registers are invalidated so clear them out */
i915_gem_reset_fences(dev);
}
/**
* This function clears the request list as sequence numbers are passed.
*/
void
i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
{
uint32_t seqno;
int i;
if (list_empty(&ring->request_list))
return;
WARN_ON(i915_verify_lists(ring->dev));
seqno = ring->get_seqno(ring, true);
for (i = 0; i < ARRAY_SIZE(ring->sync_seqno); i++)
if (seqno >= ring->sync_seqno[i])
ring->sync_seqno[i] = 0;
while (!list_empty(&ring->request_list)) {
struct drm_i915_gem_request *request;
request = list_first_entry(&ring->request_list,
struct drm_i915_gem_request,
list);
if (!i915_seqno_passed(seqno, request->seqno))
break;
trace_i915_gem_request_retire(ring, request->seqno);
/* We know the GPU must have read the request to have
* sent us the seqno + interrupt, so use the position
* of tail of the request to update the last known position
* of the GPU head.
*/
ring->last_retired_head = request->tail;
list_del(&request->list);
i915_gem_request_remove_from_client(request);
kfree(request);
}
/* Move any buffers on the active list that are no longer referenced
* by the ringbuffer to the flushing/inactive lists as appropriate.
*/
while (!list_empty(&ring->active_list)) {
struct drm_i915_gem_object *obj;
obj = list_first_entry(&ring->active_list,
struct drm_i915_gem_object,
ring_list);
if (!i915_seqno_passed(seqno, obj->last_read_seqno))
break;
i915_gem_object_move_to_inactive(obj);
}
if (unlikely(ring->trace_irq_seqno &&
i915_seqno_passed(seqno, ring->trace_irq_seqno))) {
ring->irq_put(ring);
ring->trace_irq_seqno = 0;
}
WARN_ON(i915_verify_lists(ring->dev));
}
void
i915_gem_retire_requests(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
struct intel_ring_buffer *ring;
int i;
for_each_ring(ring, dev_priv, i)
i915_gem_retire_requests_ring(ring);
}
static void
i915_gem_retire_work_handler(struct work_struct *work)
{
drm_i915_private_t *dev_priv;
struct drm_device *dev;
struct intel_ring_buffer *ring;
bool idle;
int i;
dev_priv = container_of(work, drm_i915_private_t,
mm.retire_work.work);
dev = dev_priv->dev;
/* Come back later if the device is busy... */
if (!mutex_trylock(&dev->struct_mutex)) {
queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, HZ);
return;
}
i915_gem_retire_requests(dev);
/* Send a periodic flush down the ring so we don't hold onto GEM
* objects indefinitely.
*/
idle = true;
for_each_ring(ring, dev_priv, i) {
if (ring->gpu_caches_dirty)
i915_add_request(ring, NULL, NULL);
idle &= list_empty(&ring->request_list);
}
if (!dev_priv->mm.suspended && !idle)
queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, HZ);
if (idle)
intel_mark_idle(dev);
mutex_unlock(&dev->struct_mutex);
}
int
i915_gem_check_wedge(struct drm_i915_private *dev_priv,
bool interruptible)
{
if (atomic_read(&dev_priv->mm.wedged)) {
struct completion *x = &dev_priv->error_completion;
bool recovery_complete;
unsigned long flags;
/* Give the error handler a chance to run. */
spin_lock_irqsave(&x->wait.lock, flags);
recovery_complete = x->done > 0;
spin_unlock_irqrestore(&x->wait.lock, flags);
/* Non-interruptible callers can't handle -EAGAIN, hence return
* -EIO unconditionally for these. */
if (!interruptible)
return -EIO;
/* Recovery complete, but still wedged means reset failure. */
if (recovery_complete)
return -EIO;
return -EAGAIN;
}
return 0;
}
/*
* Compare seqno against outstanding lazy request. Emit a request if they are
* equal.
*/
static int
i915_gem_check_olr(struct intel_ring_buffer *ring, u32 seqno)
{
int ret;
BUG_ON(!mutex_is_locked(&ring->dev->struct_mutex));
ret = 0;
if (seqno == ring->outstanding_lazy_request)
ret = i915_add_request(ring, NULL, NULL);
return ret;
}
/**
* __wait_seqno - wait until execution of seqno has finished
* @ring: the ring expected to report seqno
* @seqno: duh!
* @interruptible: do an interruptible wait (normally yes)
* @timeout: in - how long to wait (NULL forever); out - how much time remaining
*
* Returns 0 if the seqno was found within the alloted time. Else returns the
* errno with remaining time filled in timeout argument.
*/
static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
bool interruptible, struct timespec *timeout)
{
drm_i915_private_t *dev_priv = ring->dev->dev_private;
struct timespec before, now, wait_time={1,0};
unsigned long timeout_jiffies;
long end;
bool wait_forever = true;
int ret;
if (i915_seqno_passed(ring->get_seqno(ring, true), seqno))
return 0;
trace_i915_gem_request_wait_begin(ring, seqno);
if (timeout != NULL) {
wait_time = *timeout;
wait_forever = false;
}
timeout_jiffies = timespec_to_jiffies(&wait_time);
if (WARN_ON(!ring->irq_get(ring)))
return -ENODEV;
/* Record current time in case interrupted by signal, or wedged * */
getrawmonotonic(&before);
#define EXIT_COND \
(i915_seqno_passed(ring->get_seqno(ring, false), seqno) || \
atomic_read(&dev_priv->mm.wedged))
do {
if (interruptible)
end = wait_event_interruptible_timeout(ring->irq_queue,
EXIT_COND,
timeout_jiffies);
else
end = wait_event_timeout(ring->irq_queue, EXIT_COND,
timeout_jiffies);
ret = i915_gem_check_wedge(dev_priv, interruptible);
if (ret)
end = ret;
} while (end == 0 && wait_forever);
getrawmonotonic(&now);
ring->irq_put(ring);
trace_i915_gem_request_wait_end(ring, seqno);
#undef EXIT_COND
if (timeout) {
struct timespec sleep_time = timespec_sub(now, before);
*timeout = timespec_sub(*timeout, sleep_time);
}
switch (end) {
case -EIO:
case -EAGAIN: /* Wedged */
case -ERESTARTSYS: /* Signal */
return (int)end;
case 0: /* Timeout */
if (timeout)
set_normalized_timespec(timeout, 0, 0);
return -ETIME;
default: /* Completed */
WARN_ON(end < 0); /* We're not aware of other errors */
return 0;
}
}
/**
* Waits for a sequence number to be signaled, and cleans up the
* request and object lists appropriately for that event.
*/
int
i915_wait_seqno(struct intel_ring_buffer *ring, uint32_t seqno)
{
drm_i915_private_t *dev_priv = ring->dev->dev_private;
int ret = 0;
BUG_ON(seqno == 0);
ret = i915_gem_check_wedge(dev_priv, dev_priv->mm.interruptible);
if (ret)
return ret;
ret = i915_gem_check_olr(ring, seqno);
if (ret)
return ret;
ret = __wait_seqno(ring, seqno, dev_priv->mm.interruptible, NULL);
return ret;
}
/**
* Ensures that all rendering to the object has completed and the object is
* safe to unbind from the GTT or access from the CPU.
*/
static __must_check int
i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
bool readonly)
{
u32 seqno;
int ret;
/* If there is rendering queued on the buffer being evicted, wait for
* it.
*/
if (readonly)
seqno = obj->last_write_seqno;
else
seqno = obj->last_read_seqno;
if (seqno == 0)
return 0;
ret = i915_wait_seqno(obj->ring, seqno);
if (ret)
return ret;
/* Manually manage the write flush as we may have not yet retired
* the buffer.
*/
if (obj->last_write_seqno &&
i915_seqno_passed(seqno, obj->last_write_seqno)) {
obj->last_write_seqno = 0;
obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS;
}
i915_gem_retire_requests_ring(obj->ring);
return 0;
}
/**
* Ensures that an object will eventually get non-busy by flushing any required
* write domains, emitting any outstanding lazy request and retiring and
* completed requests.
*/
static int
i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
{
int ret;
if (obj->active) {
ret = i915_gem_check_olr(obj->ring, obj->last_read_seqno);
if (ret)
return ret;
i915_gem_retire_requests_ring(obj->ring);
}
return 0;
}
/**
* i915_gem_wait_ioctl - implements DRM_IOCTL_I915_GEM_WAIT
* @DRM_IOCTL_ARGS: standard ioctl arguments
*
* Returns 0 if successful, else an error is returned with the remaining time in
* the timeout parameter.
* -ETIME: object is still busy after timeout
* -ERESTARTSYS: signal interrupted the wait
* -ENONENT: object doesn't exist
* Also possible, but rare:
* -EAGAIN: GPU wedged
* -ENOMEM: damn
* -ENODEV: Internal IRQ fail
* -E?: The add request failed
*
* The wait ioctl with a timeout of 0 reimplements the busy ioctl. With any
* non-zero timeout parameter the wait ioctl will wait for the given number of
* nanoseconds on an object becoming unbusy. Since the wait itself does so
* without holding struct_mutex the object may become re-busied before this
* function completes. A similar but shorter * race condition exists in the busy
* ioctl
*/
int
i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
{
struct drm_i915_gem_wait *args = data;
struct drm_i915_gem_object *obj;
struct intel_ring_buffer *ring = NULL;
struct timespec timeout_stack, *timeout = NULL;
u32 seqno = 0;
int ret = 0;
if (args->timeout_ns >= 0) {
timeout_stack = ns_to_timespec(args->timeout_ns);
timeout = &timeout_stack;
}
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->bo_handle));
if (&obj->base == NULL) {
mutex_unlock(&dev->struct_mutex);
return -ENOENT;
}
/* Need to make sure the object gets inactive eventually. */
ret = i915_gem_object_flush_active(obj);
if (ret)
goto out;
if (obj->active) {
seqno = obj->last_read_seqno;
ring = obj->ring;
}
if (seqno == 0)
goto out;
/* Do this after OLR check to make sure we make forward progress polling
* on this IOCTL with a 0 timeout (like busy ioctl)
*/
if (!args->timeout_ns) {
ret = -ETIME;
goto out;
}
drm_gem_object_unreference(&obj->base);
mutex_unlock(&dev->struct_mutex);
ret = __wait_seqno(ring, seqno, true, timeout);
if (timeout) {
WARN_ON(!timespec_valid(timeout));
args->timeout_ns = timespec_to_ns(timeout);
}
return ret;
out:
drm_gem_object_unreference(&obj->base);
mutex_unlock(&dev->struct_mutex);
return ret;
}
/**
* i915_gem_object_sync - sync an object to a ring.
*
* @obj: object which may be in use on another ring.
* @to: ring we wish to use the object on. May be NULL.
*
* This code is meant to abstract object synchronization with the GPU.
* Calling with NULL implies synchronizing the object with the CPU
* rather than a particular GPU ring.
*
* Returns 0 if successful, else propagates up the lower layer error.
*/
int
i915_gem_object_sync(struct drm_i915_gem_object *obj,
struct intel_ring_buffer *to)
{
struct intel_ring_buffer *from = obj->ring;
u32 seqno;
int ret, idx;
if (from == NULL || to == from)
return 0;
if (to == NULL || !i915_semaphore_is_enabled(obj->base.dev))
return i915_gem_object_wait_rendering(obj, false);
idx = intel_ring_sync_index(from, to);
seqno = obj->last_read_seqno;
if (seqno <= from->sync_seqno[idx])
return 0;
ret = i915_gem_check_olr(obj->ring, seqno);
if (ret)
return ret;
ret = to->sync_to(to, from, seqno);
if (!ret)
from->sync_seqno[idx] = seqno;
return ret;
}
static void i915_gem_object_finish_gtt(struct drm_i915_gem_object *obj)
{
u32 old_write_domain, old_read_domains;
/* Act a barrier for all accesses through the GTT */
mb();
/* Force a pagefault for domain tracking on next user access */
i915_gem_release_mmap(obj);
if ((obj->base.read_domains & I915_GEM_DOMAIN_GTT) == 0)
return;
old_read_domains = obj->base.read_domains;
old_write_domain = obj->base.write_domain;
obj->base.read_domains &= ~I915_GEM_DOMAIN_GTT;
obj->base.write_domain &= ~I915_GEM_DOMAIN_GTT;
trace_i915_gem_object_change_domain(obj,
old_read_domains,
old_write_domain);
}
/**
* Unbinds an object from the GTT aperture.
*/
int
i915_gem_object_unbind(struct drm_i915_gem_object *obj)
{
drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
int ret = 0;
if (obj->gtt_space == NULL)
return 0;
if (obj->pin_count)
return -EBUSY;
ret = i915_gem_object_finish_gpu(obj);
if (ret)
return ret;
/* Continue on if we fail due to EIO, the GPU is hung so we
* should be safe and we need to cleanup or else we might
* cause memory corruption through use-after-free.
*/
i915_gem_object_finish_gtt(obj);
/* Move the object to the CPU domain to ensure that
* any possible CPU writes while it's not in the GTT
* are flushed when we go to remap it.
*/
if (ret == 0)
ret = i915_gem_object_set_to_cpu_domain(obj, 1);
if (ret == -ERESTARTSYS)
return ret;
if (ret) {
/* In the event of a disaster, abandon all caches and
* hope for the best.
*/
i915_gem_clflush_object(obj);
obj->base.read_domains = obj->base.write_domain = I915_GEM_DOMAIN_CPU;
}
/* release the fence reg _after_ flushing */
ret = i915_gem_object_put_fence(obj);
if (ret)
return ret;
trace_i915_gem_object_unbind(obj);
if (obj->has_global_gtt_mapping)
i915_gem_gtt_unbind_object(obj);
if (obj->has_aliasing_ppgtt_mapping) {
i915_ppgtt_unbind_object(dev_priv->mm.aliasing_ppgtt, obj);
obj->has_aliasing_ppgtt_mapping = 0;
}
i915_gem_gtt_finish_object(obj);
i915_gem_object_put_pages_gtt(obj);
list_del_init(&obj->gtt_list);
list_del_init(&obj->mm_list);
/* Avoid an unnecessary call to unbind on rebind. */
obj->map_and_fenceable = true;
drm_mm_put_block(obj->gtt_space);
obj->gtt_space = NULL;
obj->gtt_offset = 0;
if (i915_gem_object_is_purgeable(obj))
i915_gem_object_truncate(obj);
return ret;
}
static int i915_ring_idle(struct intel_ring_buffer *ring)
{
if (list_empty(&ring->active_list))
return 0;
return i915_wait_seqno(ring, i915_gem_next_request_seqno(ring));
}
int i915_gpu_idle(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
struct intel_ring_buffer *ring;
int ret, i;
/* Flush everything onto the inactive list. */
for_each_ring(ring, dev_priv, i) {
ret = i915_ring_idle(ring);
if (ret)
return ret;
ret = i915_switch_context(ring, NULL, DEFAULT_CONTEXT_ID);
if (ret)
return ret;
}
return 0;
}
static void sandybridge_write_fence_reg(struct drm_device *dev, int reg,
struct drm_i915_gem_object *obj)
{
drm_i915_private_t *dev_priv = dev->dev_private;
uint64_t val;
if (obj) {
u32 size = obj->gtt_space->size;
val = (uint64_t)((obj->gtt_offset + size - 4096) &
0xfffff000) << 32;
val |= obj->gtt_offset & 0xfffff000;
val |= (uint64_t)((obj->stride / 128) - 1) <<
SANDYBRIDGE_FENCE_PITCH_SHIFT;
if (obj->tiling_mode == I915_TILING_Y)
val |= 1 << I965_FENCE_TILING_Y_SHIFT;
val |= I965_FENCE_REG_VALID;
} else
val = 0;
I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 + reg * 8, val);
POSTING_READ(FENCE_REG_SANDYBRIDGE_0 + reg * 8);
}
static void i965_write_fence_reg(struct drm_device *dev, int reg,
struct drm_i915_gem_object *obj)
{
drm_i915_private_t *dev_priv = dev->dev_private;
uint64_t val;
if (obj) {
u32 size = obj->gtt_space->size;
val = (uint64_t)((obj->gtt_offset + size - 4096) &
0xfffff000) << 32;
val |= obj->gtt_offset & 0xfffff000;
val |= ((obj->stride / 128) - 1) << I965_FENCE_PITCH_SHIFT;
if (obj->tiling_mode == I915_TILING_Y)
val |= 1 << I965_FENCE_TILING_Y_SHIFT;
val |= I965_FENCE_REG_VALID;
} else
val = 0;
I915_WRITE64(FENCE_REG_965_0 + reg * 8, val);
POSTING_READ(FENCE_REG_965_0 + reg * 8);
}
static void i915_write_fence_reg(struct drm_device *dev, int reg,
struct drm_i915_gem_object *obj)
{
drm_i915_private_t *dev_priv = dev->dev_private;
u32 val;
if (obj) {
u32 size = obj->gtt_space->size;
int pitch_val;
int tile_width;
WARN((obj->gtt_offset & ~I915_FENCE_START_MASK) ||
(size & -size) != size ||
(obj->gtt_offset & (size - 1)),
"object 0x%08x [fenceable? %d] not 1M or pot-size (0x%08x) aligned\n",
obj->gtt_offset, obj->map_and_fenceable, size);
if (obj->tiling_mode == I915_TILING_Y && HAS_128_BYTE_Y_TILING(dev))
tile_width = 128;
else
tile_width = 512;
/* Note: pitch better be a power of two tile widths */
pitch_val = obj->stride / tile_width;
pitch_val = ffs(pitch_val) - 1;
val = obj->gtt_offset;
if (obj->tiling_mode == I915_TILING_Y)
val |= 1 << I830_FENCE_TILING_Y_SHIFT;
val |= I915_FENCE_SIZE_BITS(size);
val |= pitch_val << I830_FENCE_PITCH_SHIFT;
val |= I830_FENCE_REG_VALID;
} else
val = 0;
if (reg < 8)
reg = FENCE_REG_830_0 + reg * 4;
else
reg = FENCE_REG_945_8 + (reg - 8) * 4;
I915_WRITE(reg, val);
POSTING_READ(reg);
}
static void i830_write_fence_reg(struct drm_device *dev, int reg,
struct drm_i915_gem_object *obj)
{
drm_i915_private_t *dev_priv = dev->dev_private;
uint32_t val;
if (obj) {
u32 size = obj->gtt_space->size;
uint32_t pitch_val;
WARN((obj->gtt_offset & ~I830_FENCE_START_MASK) ||
(size & -size) != size ||
(obj->gtt_offset & (size - 1)),
"object 0x%08x not 512K or pot-size 0x%08x aligned\n",
obj->gtt_offset, size);
pitch_val = obj->stride / 128;
pitch_val = ffs(pitch_val) - 1;
val = obj->gtt_offset;
if (obj->tiling_mode == I915_TILING_Y)
val |= 1 << I830_FENCE_TILING_Y_SHIFT;
val |= I830_FENCE_SIZE_BITS(size);
val |= pitch_val << I830_FENCE_PITCH_SHIFT;
val |= I830_FENCE_REG_VALID;
} else
val = 0;
I915_WRITE(FENCE_REG_830_0 + reg * 4, val);
POSTING_READ(FENCE_REG_830_0 + reg * 4);
}
static void i915_gem_write_fence(struct drm_device *dev, int reg,
struct drm_i915_gem_object *obj)
{
switch (INTEL_INFO(dev)->gen) {
case 7:
case 6: sandybridge_write_fence_reg(dev, reg, obj); break;
case 5:
case 4: i965_write_fence_reg(dev, reg, obj); break;
case 3: i915_write_fence_reg(dev, reg, obj); break;
case 2: i830_write_fence_reg(dev, reg, obj); break;
default: break;
}
}
static inline int fence_number(struct drm_i915_private *dev_priv,
struct drm_i915_fence_reg *fence)
{
return fence - dev_priv->fence_regs;
}
static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
struct drm_i915_fence_reg *fence,
bool enable)
{
struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
int reg = fence_number(dev_priv, fence);
i915_gem_write_fence(obj->base.dev, reg, enable ? obj : NULL);
if (enable) {
obj->fence_reg = reg;
fence->obj = obj;
list_move_tail(&fence->lru_list, &dev_priv->mm.fence_list);
} else {
obj->fence_reg = I915_FENCE_REG_NONE;
fence->obj = NULL;
list_del_init(&fence->lru_list);
}
}
static int
i915_gem_object_flush_fence(struct drm_i915_gem_object *obj)
{
if (obj->last_fenced_seqno) {
int ret = i915_wait_seqno(obj->ring, obj->last_fenced_seqno);
if (ret)
return ret;
obj->last_fenced_seqno = 0;
}
/* Ensure that all CPU reads are completed before installing a fence
* and all writes before removing the fence.
*/
if (obj->base.read_domains & I915_GEM_DOMAIN_GTT)
mb();
obj->fenced_gpu_access = false;
return 0;
}
int
i915_gem_object_put_fence(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
int ret;
ret = i915_gem_object_flush_fence(obj);
if (ret)
return ret;
if (obj->fence_reg == I915_FENCE_REG_NONE)
return 0;
i915_gem_object_update_fence(obj,
&dev_priv->fence_regs[obj->fence_reg],
false);
i915_gem_object_fence_lost(obj);
return 0;
}
static struct drm_i915_fence_reg *
i915_find_fence_reg(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_fence_reg *reg, *avail;
int i;
/* First try to find a free reg */
avail = NULL;
for (i = dev_priv->fence_reg_start; i < dev_priv->num_fence_regs; i++) {
reg = &dev_priv->fence_regs[i];
if (!reg->obj)
return reg;
if (!reg->pin_count)
avail = reg;
}
if (avail == NULL)
return NULL;
/* None available, try to steal one or wait for a user to finish */
list_for_each_entry(reg, &dev_priv->mm.fence_list, lru_list) {
if (reg->pin_count)
continue;
return reg;
}
return NULL;
}
/**
* i915_gem_object_get_fence - set up fencing for an object
* @obj: object to map through a fence reg
*
* When mapping objects through the GTT, userspace wants to be able to write
* to them without having to worry about swizzling if the object is tiled.
* This function walks the fence regs looking for a free one for @obj,
* stealing one if it can't find any.
*
* It then sets up the reg based on the object's properties: address, pitch
* and tiling format.
*
* For an untiled surface, this removes any existing fence.
*/
int
i915_gem_object_get_fence(struct drm_i915_gem_object *obj)
{
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
bool enable = obj->tiling_mode != I915_TILING_NONE;
struct drm_i915_fence_reg *reg;
int ret;
/* Have we updated the tiling parameters upon the object and so
* will need to serialise the write to the associated fence register?
*/
if (obj->fence_dirty) {
ret = i915_gem_object_flush_fence(obj);
if (ret)
return ret;
}
/* Just update our place in the LRU if our fence is getting reused. */
if (obj->fence_reg != I915_FENCE_REG_NONE) {
reg = &dev_priv->fence_regs[obj->fence_reg];
if (!obj->fence_dirty) {
list_move_tail(&reg->lru_list,
&dev_priv->mm.fence_list);
return 0;
}
} else if (enable) {
reg = i915_find_fence_reg(dev);
if (reg == NULL)
return -EDEADLK;
if (reg->obj) {
struct drm_i915_gem_object *old = reg->obj;
ret = i915_gem_object_flush_fence(old);
if (ret)
return ret;
i915_gem_object_fence_lost(old);
}
} else
return 0;
i915_gem_object_update_fence(obj, reg, enable);
obj->fence_dirty = false;
return 0;
}
static bool i915_gem_valid_gtt_space(struct drm_device *dev,
struct drm_mm_node *gtt_space,
unsigned long cache_level)
{
struct drm_mm_node *other;
/* On non-LLC machines we have to be careful when putting differing
* types of snoopable memory together to avoid the prefetcher
* crossing memory domains and dieing.
*/
if (HAS_LLC(dev))
return true;
if (gtt_space == NULL)
return true;
if (list_empty(&gtt_space->node_list))
return true;
other = list_entry(gtt_space->node_list.prev, struct drm_mm_node, node_list);
if (other->allocated && !other->hole_follows && other->color != cache_level)
return false;
other = list_entry(gtt_space->node_list.next, struct drm_mm_node, node_list);
if (other->allocated && !gtt_space->hole_follows && other->color != cache_level)
return false;
return true;
}
static void i915_gem_verify_gtt(struct drm_device *dev)
{
#if WATCH_GTT
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_object *obj;
int err = 0;
list_for_each_entry(obj, &dev_priv->mm.gtt_list, gtt_list) {
if (obj->gtt_space == NULL) {
printk(KERN_ERR "object found on GTT list with no space reserved\n");
err++;
continue;
}
if (obj->cache_level != obj->gtt_space->color) {
printk(KERN_ERR "object reserved space [%08lx, %08lx] with wrong color, cache_level=%x, color=%lx\n",
obj->gtt_space->start,
obj->gtt_space->start + obj->gtt_space->size,
obj->cache_level,
obj->gtt_space->color);
err++;
continue;
}
if (!i915_gem_valid_gtt_space(dev,
obj->gtt_space,
obj->cache_level)) {
printk(KERN_ERR "invalid GTT space found at [%08lx, %08lx] - color=%x\n",
obj->gtt_space->start,
obj->gtt_space->start + obj->gtt_space->size,
obj->cache_level);
err++;
continue;
}
}
WARN_ON(err);
#endif
}
/**
* Finds free space in the GTT aperture and binds the object there.
*/
static int
i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
unsigned alignment,
bool map_and_fenceable)
{
struct drm_device *dev = obj->base.dev;
drm_i915_private_t *dev_priv = dev->dev_private;
struct drm_mm_node *free_space;
gfp_t gfpmask = __GFP_NORETRY | __GFP_NOWARN;
u32 size, fence_size, fence_alignment, unfenced_alignment;
bool mappable, fenceable;
int ret;
if (obj->madv != I915_MADV_WILLNEED) {
DRM_ERROR("Attempting to bind a purgeable object\n");
return -EINVAL;
}
fence_size = i915_gem_get_gtt_size(dev,
obj->base.size,
obj->tiling_mode);
fence_alignment = i915_gem_get_gtt_alignment(dev,
obj->base.size,
obj->tiling_mode);
unfenced_alignment =
i915_gem_get_unfenced_gtt_alignment(dev,
obj->base.size,
obj->tiling_mode);
if (alignment == 0)
alignment = map_and_fenceable ? fence_alignment :
unfenced_alignment;
if (map_and_fenceable && alignment & (fence_alignment - 1)) {
DRM_ERROR("Invalid object alignment requested %u\n", alignment);
return -EINVAL;
}
size = map_and_fenceable ? fence_size : obj->base.size;
/* If the object is bigger than the entire aperture, reject it early
* before evicting everything in a vain attempt to find space.
*/
if (obj->base.size >
(map_and_fenceable ? dev_priv->mm.gtt_mappable_end : dev_priv->mm.gtt_total)) {
DRM_ERROR("Attempting to bind an object larger than the aperture\n");
return -E2BIG;
}
search_free:
if (map_and_fenceable)
free_space =
drm_mm_search_free_in_range_color(&dev_priv->mm.gtt_space,
size, alignment, obj->cache_level,
0, dev_priv->mm.gtt_mappable_end,
false);
else
free_space = drm_mm_search_free_color(&dev_priv->mm.gtt_space,
size, alignment, obj->cache_level,
false);
if (free_space != NULL) {
if (map_and_fenceable)
obj->gtt_space =
drm_mm_get_block_range_generic(free_space,
size, alignment, obj->cache_level,
0, dev_priv->mm.gtt_mappable_end,
false);
else
obj->gtt_space =
drm_mm_get_block_generic(free_space,
size, alignment, obj->cache_level,
false);
}
if (obj->gtt_space == NULL) {
/* If the gtt is empty and we're still having trouble
* fitting our object in, we're out of memory.
*/
ret = i915_gem_evict_something(dev, size, alignment,
obj->cache_level,
map_and_fenceable);
if (ret)
return ret;
goto search_free;
}
if (WARN_ON(!i915_gem_valid_gtt_space(dev,
obj->gtt_space,
obj->cache_level))) {
drm_mm_put_block(obj->gtt_space);
obj->gtt_space = NULL;
return -EINVAL;
}
ret = i915_gem_object_get_pages_gtt(obj, gfpmask);
if (ret) {
drm_mm_put_block(obj->gtt_space);
obj->gtt_space = NULL;
if (ret == -ENOMEM) {
/* first try to reclaim some memory by clearing the GTT */
ret = i915_gem_evict_everything(dev, false);
if (ret) {
/* now try to shrink everyone else */
if (gfpmask) {
gfpmask = 0;
goto search_free;
}
return -ENOMEM;
}
goto search_free;
}
return ret;
}
ret = i915_gem_gtt_prepare_object(obj);
if (ret) {
i915_gem_object_put_pages_gtt(obj);
drm_mm_put_block(obj->gtt_space);
obj->gtt_space = NULL;
if (i915_gem_evict_everything(dev, false))
return ret;
goto search_free;
}
if (!dev_priv->mm.aliasing_ppgtt)
i915_gem_gtt_bind_object(obj, obj->cache_level);
list_add_tail(&obj->gtt_list, &dev_priv->mm.gtt_list);
list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
/* Assert that the object is not currently in any GPU domain. As it
* wasn't in the GTT, there shouldn't be any way it could have been in
* a GPU cache
*/
BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS);
BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS);
obj->gtt_offset = obj->gtt_space->start;
fenceable =
obj->gtt_space->size == fence_size &&
(obj->gtt_space->start & (fence_alignment - 1)) == 0;
mappable =
obj->gtt_offset + obj->base.size <= dev_priv->mm.gtt_mappable_end;
obj->map_and_fenceable = mappable && fenceable;
trace_i915_gem_object_bind(obj, map_and_fenceable);
i915_gem_verify_gtt(dev);
return 0;
}
void
i915_gem_clflush_object(struct drm_i915_gem_object *obj)
{
/* If we don't have a page list set up, then we're not pinned
* to GPU, and we can ignore the cache flush because it'll happen
* again at bind time.
*/
if (obj->pages == NULL)
return;
/* If the GPU is snooping the contents of the CPU cache,
* we do not need to manually clear the CPU cache lines. However,
* the caches are only snooped when the render cache is
* flushed/invalidated. As we always have to emit invalidations
* and flushes when moving into and out of the RENDER domain, correct
* snooping behaviour occurs naturally as the result of our domain
* tracking.
*/
if (obj->cache_level != I915_CACHE_NONE)
return;
trace_i915_gem_object_clflush(obj);
drm_clflush_pages(obj->pages, obj->base.size / PAGE_SIZE);
}
/** Flushes the GTT write domain for the object if it's dirty. */
static void
i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj)
{
uint32_t old_write_domain;
if (obj->base.write_domain != I915_GEM_DOMAIN_GTT)
return;
/* No actual flushing is required for the GTT write domain. Writes
* to it immediately go to main memory as far as we know, so there's
* no chipset flush. It also doesn't land in render cache.
*
* However, we do have to enforce the order so that all writes through
* the GTT land before any writes to the device, such as updates to
* the GATT itself.
*/
wmb();
old_write_domain = obj->base.write_domain;
obj->base.write_domain = 0;
trace_i915_gem_object_change_domain(obj,
obj->base.read_domains,
old_write_domain);
}
/** Flushes the CPU write domain for the object if it's dirty. */
static void
i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj)
{
uint32_t old_write_domain;
if (obj->base.write_domain != I915_GEM_DOMAIN_CPU)
return;
i915_gem_clflush_object(obj);
intel_gtt_chipset_flush();
old_write_domain = obj->base.write_domain;
obj->base.write_domain = 0;
trace_i915_gem_object_change_domain(obj,
obj->base.read_domains,
old_write_domain);
}
/**
* Moves a single object to the GTT read, and possibly write domain.
*
* This function returns when the move is complete, including waiting on
* flushes to occur.
*/
int
i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
{
drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
uint32_t old_write_domain, old_read_domains;
int ret;
/* Not valid to be called on unbound objects. */
if (obj->gtt_space == NULL)
return -EINVAL;
if (obj->base.write_domain == I915_GEM_DOMAIN_GTT)
return 0;
ret = i915_gem_object_wait_rendering(obj, !write);
if (ret)
return ret;
i915_gem_object_flush_cpu_write_domain(obj);
old_write_domain = obj->base.write_domain;
old_read_domains = obj->base.read_domains;
/* It should now be out of any other write domains, and we can update
* the domain values for our changes.
*/
BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_GTT) != 0);
obj->base.read_domains |= I915_GEM_DOMAIN_GTT;
if (write) {
obj->base.read_domains = I915_GEM_DOMAIN_GTT;
obj->base.write_domain = I915_GEM_DOMAIN_GTT;
obj->dirty = 1;
}
trace_i915_gem_object_change_domain(obj,
old_read_domains,
old_write_domain);
/* And bump the LRU for this access */
if (i915_gem_object_is_inactive(obj))
list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
return 0;
}
int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
enum i915_cache_level cache_level)
{
struct drm_device *dev = obj->base.dev;
drm_i915_private_t *dev_priv = dev->dev_private;
int ret;
if (obj->cache_level == cache_level)
return 0;
if (obj->pin_count) {
DRM_DEBUG("can not change the cache level of pinned objects\n");
return -EBUSY;
}
if (!i915_gem_valid_gtt_space(dev, obj->gtt_space, cache_level)) {
ret = i915_gem_object_unbind(obj);
if (ret)
return ret;
}
if (obj->gtt_space) {
ret = i915_gem_object_finish_gpu(obj);
if (ret)
return ret;
i915_gem_object_finish_gtt(obj);
/* Before SandyBridge, you could not use tiling or fence
* registers with snooped memory, so relinquish any fences
* currently pointing to our region in the aperture.
*/
if (INTEL_INFO(dev)->gen < 6) {
ret = i915_gem_object_put_fence(obj);
if (ret)
return ret;
}
if (obj->has_global_gtt_mapping)
i915_gem_gtt_bind_object(obj, cache_level);
if (obj->has_aliasing_ppgtt_mapping)
i915_ppgtt_bind_object(dev_priv->mm.aliasing_ppgtt,
obj, cache_level);
obj->gtt_space->color = cache_level;
}
if (cache_level == I915_CACHE_NONE) {
u32 old_read_domains, old_write_domain;
/* If we're coming from LLC cached, then we haven't
* actually been tracking whether the data is in the
* CPU cache or not, since we only allow one bit set
* in obj->write_domain and have been skipping the clflushes.
* Just set it to the CPU cache for now.
*/
WARN_ON(obj->base.write_domain & ~I915_GEM_DOMAIN_CPU);
WARN_ON(obj->base.read_domains & ~I915_GEM_DOMAIN_CPU);
old_read_domains = obj->base.read_domains;
old_write_domain = obj->base.write_domain;
obj->base.read_domains = I915_GEM_DOMAIN_CPU;
obj->base.write_domain = I915_GEM_DOMAIN_CPU;
trace_i915_gem_object_change_domain(obj,
old_read_domains,
old_write_domain);
}
obj->cache_level = cache_level;
i915_gem_verify_gtt(dev);
return 0;
}
int i915_gem_get_cacheing_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_cacheing *args = data;
struct drm_i915_gem_object *obj;
int ret;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
args->cacheing = obj->cache_level != I915_CACHE_NONE;
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
int i915_gem_set_cacheing_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_cacheing *args = data;
struct drm_i915_gem_object *obj;
enum i915_cache_level level;
int ret;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
switch (args->cacheing) {
case I915_CACHEING_NONE:
level = I915_CACHE_NONE;
break;
case I915_CACHEING_CACHED:
level = I915_CACHE_LLC;
break;
default:
return -EINVAL;
}
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
ret = i915_gem_object_set_cache_level(obj, level);
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
/*
* Prepare buffer for display plane (scanout, cursors, etc).
* Can be called from an uninterruptible phase (modesetting) and allows
* any flushes to be pipelined (for pageflips).
*/
int
i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
u32 alignment,
struct intel_ring_buffer *pipelined)
{
u32 old_read_domains, old_write_domain;
int ret;
if (pipelined != obj->ring) {
ret = i915_gem_object_sync(obj, pipelined);
if (ret)
return ret;
}
/* The display engine is not coherent with the LLC cache on gen6. As
* a result, we make sure that the pinning that is about to occur is
* done with uncached PTEs. This is lowest common denominator for all
* chipsets.
*
* However for gen6+, we could do better by using the GFDT bit instead
* of uncaching, which would allow us to flush all the LLC-cached data
* with that bit in the PTE to main memory with just one PIPE_CONTROL.
*/
ret = i915_gem_object_set_cache_level(obj, I915_CACHE_NONE);
if (ret)
return ret;
/* As the user may map the buffer once pinned in the display plane
* (e.g. libkms for the bootup splash), we have to ensure that we
* always use map_and_fenceable for all scanout buffers.
*/
ret = i915_gem_object_pin(obj, alignment, true);
if (ret)
return ret;
i915_gem_object_flush_cpu_write_domain(obj);
old_write_domain = obj->base.write_domain;
old_read_domains = obj->base.read_domains;
/* It should now be out of any other write domains, and we can update
* the domain values for our changes.
*/
obj->base.write_domain = 0;
obj->base.read_domains |= I915_GEM_DOMAIN_GTT;
trace_i915_gem_object_change_domain(obj,
old_read_domains,
old_write_domain);
return 0;
}
int
i915_gem_object_finish_gpu(struct drm_i915_gem_object *obj)
{
int ret;
if ((obj->base.read_domains & I915_GEM_GPU_DOMAINS) == 0)
return 0;
ret = i915_gem_object_wait_rendering(obj, false);
if (ret)
return ret;
/* Ensure that we invalidate the GPU's caches and TLBs. */
obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
return 0;
}
/**
* Moves a single object to the CPU read, and possibly write domain.
*
* This function returns when the move is complete, including waiting on
* flushes to occur.
*/
int
i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write)
{
uint32_t old_write_domain, old_read_domains;
int ret;
if (obj->base.write_domain == I915_GEM_DOMAIN_CPU)
return 0;
ret = i915_gem_object_wait_rendering(obj, !write);
if (ret)
return ret;
i915_gem_object_flush_gtt_write_domain(obj);
old_write_domain = obj->base.write_domain;
old_read_domains = obj->base.read_domains;
/* Flush the CPU cache if it's still invalid. */
if ((obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0) {
i915_gem_clflush_object(obj);
obj->base.read_domains |= I915_GEM_DOMAIN_CPU;
}
/* It should now be out of any other write domains, and we can update
* the domain values for our changes.
*/
BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_CPU) != 0);
/* If we're writing through the CPU, then the GPU read domains will
* need to be invalidated at next use.
*/
if (write) {
obj->base.read_domains = I915_GEM_DOMAIN_CPU;
obj->base.write_domain = I915_GEM_DOMAIN_CPU;
}
trace_i915_gem_object_change_domain(obj,
old_read_domains,
old_write_domain);
return 0;
}
/* Throttle our rendering by waiting until the ring has completed our requests
* emitted over 20 msec ago.
*
* Note that if we were to use the current jiffies each time around the loop,
* we wouldn't escape the function with any frames outstanding if the time to
* render a frame was over 20ms.
*
* This should get us reasonable parallelism between CPU and GPU but also
* relatively low latency when blocking on a particular request to finish.
*/
static int
i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_file_private *file_priv = file->driver_priv;
unsigned long recent_enough = jiffies - msecs_to_jiffies(20);
struct drm_i915_gem_request *request;
struct intel_ring_buffer *ring = NULL;
u32 seqno = 0;
int ret;
if (atomic_read(&dev_priv->mm.wedged))
return -EIO;
spin_lock(&file_priv->mm.lock);
list_for_each_entry(request, &file_priv->mm.request_list, client_list) {
if (time_after_eq(request->emitted_jiffies, recent_enough))
break;
ring = request->ring;
seqno = request->seqno;
}
spin_unlock(&file_priv->mm.lock);
if (seqno == 0)
return 0;
ret = __wait_seqno(ring, seqno, true, NULL);
if (ret == 0)
queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, 0);
return ret;
}
int
i915_gem_object_pin(struct drm_i915_gem_object *obj,
uint32_t alignment,
bool map_and_fenceable)
{
int ret;
BUG_ON(obj->pin_count == DRM_I915_GEM_OBJECT_MAX_PIN_COUNT);
if (obj->gtt_space != NULL) {
if ((alignment && obj->gtt_offset & (alignment - 1)) ||
(map_and_fenceable && !obj->map_and_fenceable)) {
WARN(obj->pin_count,
"bo is already pinned with incorrect alignment:"
" offset=%x, req.alignment=%x, req.map_and_fenceable=%d,"
" obj->map_and_fenceable=%d\n",
obj->gtt_offset, alignment,
map_and_fenceable,
obj->map_and_fenceable);
ret = i915_gem_object_unbind(obj);
if (ret)
return ret;
}
}
if (obj->gtt_space == NULL) {
ret = i915_gem_object_bind_to_gtt(obj, alignment,
map_and_fenceable);
if (ret)
return ret;
}
if (!obj->has_global_gtt_mapping && map_and_fenceable)
i915_gem_gtt_bind_object(obj, obj->cache_level);
obj->pin_count++;
obj->pin_mappable |= map_and_fenceable;
return 0;
}
void
i915_gem_object_unpin(struct drm_i915_gem_object *obj)
{
BUG_ON(obj->pin_count == 0);
BUG_ON(obj->gtt_space == NULL);
if (--obj->pin_count == 0)
obj->pin_mappable = false;
}
int
i915_gem_pin_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_pin *args = data;
struct drm_i915_gem_object *obj;
int ret;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
if (obj->madv != I915_MADV_WILLNEED) {
DRM_ERROR("Attempting to pin a purgeable buffer\n");
ret = -EINVAL;
goto out;
}
if (obj->pin_filp != NULL && obj->pin_filp != file) {
DRM_ERROR("Already pinned in i915_gem_pin_ioctl(): %d\n",
args->handle);
ret = -EINVAL;
goto out;
}
obj->user_pin_count++;
obj->pin_filp = file;
if (obj->user_pin_count == 1) {
ret = i915_gem_object_pin(obj, args->alignment, true);
if (ret)
goto out;
}
/* XXX - flush the CPU caches for pinned objects
* as the X server doesn't manage domains yet
*/
i915_gem_object_flush_cpu_write_domain(obj);
args->offset = obj->gtt_offset;
out:
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
int
i915_gem_unpin_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_pin *args = data;
struct drm_i915_gem_object *obj;
int ret;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
if (obj->pin_filp != file) {
DRM_ERROR("Not pinned by caller in i915_gem_pin_ioctl(): %d\n",
args->handle);
ret = -EINVAL;
goto out;
}
obj->user_pin_count--;
if (obj->user_pin_count == 0) {
obj->pin_filp = NULL;
i915_gem_object_unpin(obj);
}
out:
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
int
i915_gem_busy_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_busy *args = data;
struct drm_i915_gem_object *obj;
int ret;
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
/* Count all active objects as busy, even if they are currently not used
* by the gpu. Users of this interface expect objects to eventually
* become non-busy without any further actions, therefore emit any
* necessary flushes here.
*/
ret = i915_gem_object_flush_active(obj);
args->busy = obj->active;
if (obj->ring) {
BUILD_BUG_ON(I915_NUM_RINGS > 16);
args->busy |= intel_ring_flag(obj->ring) << 16;
}
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
int
i915_gem_throttle_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
return i915_gem_ring_throttle(dev, file_priv);
}
int
i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_i915_gem_madvise *args = data;
struct drm_i915_gem_object *obj;
int ret;
switch (args->madv) {
case I915_MADV_DONTNEED:
case I915_MADV_WILLNEED:
break;
default:
return -EINVAL;
}
ret = i915_mutex_lock_interruptible(dev);
if (ret)
return ret;
obj = to_intel_bo(drm_gem_object_lookup(dev, file_priv, args->handle));
if (&obj->base == NULL) {
ret = -ENOENT;
goto unlock;
}
if (obj->pin_count) {
ret = -EINVAL;
goto out;
}
if (obj->madv != __I915_MADV_PURGED)
obj->madv = args->madv;
/* if the object is no longer bound, discard its backing storage */
if (i915_gem_object_is_purgeable(obj) &&
obj->gtt_space == NULL)
i915_gem_object_truncate(obj);
args->retained = obj->madv != __I915_MADV_PURGED;
out:
drm_gem_object_unreference(&obj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
size_t size)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_object *obj;
struct address_space *mapping;
u32 mask;
obj = kzalloc(sizeof(*obj), GFP_KERNEL);
if (obj == NULL)
return NULL;
if (drm_gem_object_init(dev, &obj->base, size) != 0) {
kfree(obj);
return NULL;
}
mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
if (IS_CRESTLINE(dev) || IS_BROADWATER(dev)) {
/* 965gm cannot relocate objects above 4GiB. */
mask &= ~__GFP_HIGHMEM;
mask |= __GFP_DMA32;
}
mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
mapping_set_gfp_mask(mapping, mask);
i915_gem_info_add_obj(dev_priv, size);
obj->base.write_domain = I915_GEM_DOMAIN_CPU;
obj->base.read_domains = I915_GEM_DOMAIN_CPU;
if (HAS_LLC(dev)) {
/* On some devices, we can have the GPU use the LLC (the CPU
* cache) for about a 10% performance improvement
* compared to uncached. Graphics requests other than
* display scanout are coherent with the CPU in
* accessing this cache. This means in this mode we
* don't need to clflush on the CPU side, and on the
* GPU side we only need to flush internal caches to
* get data visible to the CPU.
*
* However, we maintain the display planes as UC, and so
* need to rebind when first used as such.
*/
obj->cache_level = I915_CACHE_LLC;
} else
obj->cache_level = I915_CACHE_NONE;
obj->base.driver_private = NULL;
obj->fence_reg = I915_FENCE_REG_NONE;
INIT_LIST_HEAD(&obj->mm_list);
INIT_LIST_HEAD(&obj->gtt_list);
INIT_LIST_HEAD(&obj->ring_list);
INIT_LIST_HEAD(&obj->exec_list);
obj->madv = I915_MADV_WILLNEED;
/* Avoid an unnecessary call to unbind on the first bind. */
obj->map_and_fenceable = true;
return obj;
}
int i915_gem_init_object(struct drm_gem_object *obj)
{
BUG();
return 0;
}
void i915_gem_free_object(struct drm_gem_object *gem_obj)
{
struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
struct drm_device *dev = obj->base.dev;
drm_i915_private_t *dev_priv = dev->dev_private;
trace_i915_gem_object_destroy(obj);
if (gem_obj->import_attach)
drm_prime_gem_destroy(gem_obj, obj->sg_table);
if (obj->phys_obj)
i915_gem_detach_phys_object(dev, obj);
obj->pin_count = 0;
if (WARN_ON(i915_gem_object_unbind(obj) == -ERESTARTSYS)) {
bool was_interruptible;
was_interruptible = dev_priv->mm.interruptible;
dev_priv->mm.interruptible = false;
WARN_ON(i915_gem_object_unbind(obj));
dev_priv->mm.interruptible = was_interruptible;
}
if (obj->base.map_list.map)
drm_gem_free_mmap_offset(&obj->base);
drm_gem_object_release(&obj->base);
i915_gem_info_remove_obj(dev_priv, obj->base.size);
kfree(obj->bit_17);
kfree(obj);
}
int
i915_gem_idle(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
int ret;
mutex_lock(&dev->struct_mutex);
if (dev_priv->mm.suspended) {
mutex_unlock(&dev->struct_mutex);
return 0;
}
ret = i915_gpu_idle(dev);
if (ret) {
mutex_unlock(&dev->struct_mutex);
return ret;
}
i915_gem_retire_requests(dev);
/* Under UMS, be paranoid and evict. */
if (!drm_core_check_feature(dev, DRIVER_MODESET))
i915_gem_evict_everything(dev, false);
i915_gem_reset_fences(dev);
/* Hack! Don't let anybody do execbuf while we don't control the chip.
* We need to replace this with a semaphore, or something.
* And not confound mm.suspended!
*/
dev_priv->mm.suspended = 1;
del_timer_sync(&dev_priv->hangcheck_timer);
i915_kernel_lost_context(dev);
i915_gem_cleanup_ringbuffer(dev);
mutex_unlock(&dev->struct_mutex);
/* Cancel the retire work handler, which should be idle now. */
cancel_delayed_work_sync(&dev_priv->mm.retire_work);
return 0;
}
void i915_gem_l3_remap(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
u32 misccpctl;
int i;
if (!IS_IVYBRIDGE(dev))
return;
if (!dev_priv->mm.l3_remap_info)
return;
misccpctl = I915_READ(GEN7_MISCCPCTL);
I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
POSTING_READ(GEN7_MISCCPCTL);
for (i = 0; i < GEN7_L3LOG_SIZE; i += 4) {
u32 remap = I915_READ(GEN7_L3LOG_BASE + i);
if (remap && remap != dev_priv->mm.l3_remap_info[i/4])
DRM_DEBUG("0x%x was already programmed to %x\n",
GEN7_L3LOG_BASE + i, remap);
if (remap && !dev_priv->mm.l3_remap_info[i/4])
DRM_DEBUG_DRIVER("Clearing remapped register\n");
I915_WRITE(GEN7_L3LOG_BASE + i, dev_priv->mm.l3_remap_info[i/4]);
}
/* Make sure all the writes land before disabling dop clock gating */
POSTING_READ(GEN7_L3LOG_BASE);
I915_WRITE(GEN7_MISCCPCTL, misccpctl);
}
void i915_gem_init_swizzling(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
if (INTEL_INFO(dev)->gen < 5 ||
dev_priv->mm.bit_6_swizzle_x == I915_BIT_6_SWIZZLE_NONE)
return;
I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
DISP_TILE_SURFACE_SWIZZLING);
if (IS_GEN5(dev))
return;
I915_WRITE(TILECTL, I915_READ(TILECTL) | TILECTL_SWZCTL);
if (IS_GEN6(dev))
I915_WRITE(ARB_MODE, _MASKED_BIT_ENABLE(ARB_MODE_SWIZZLE_SNB));
else
I915_WRITE(ARB_MODE, _MASKED_BIT_ENABLE(ARB_MODE_SWIZZLE_IVB));
}
void i915_gem_init_ppgtt(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
uint32_t pd_offset;
struct intel_ring_buffer *ring;
struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
uint32_t __iomem *pd_addr;
uint32_t pd_entry;
int i;
if (!dev_priv->mm.aliasing_ppgtt)
return;
pd_addr = dev_priv->mm.gtt->gtt + ppgtt->pd_offset/sizeof(uint32_t);
for (i = 0; i < ppgtt->num_pd_entries; i++) {
dma_addr_t pt_addr;
if (dev_priv->mm.gtt->needs_dmar)
pt_addr = ppgtt->pt_dma_addr[i];
else
pt_addr = page_to_phys(ppgtt->pt_pages[i]);
pd_entry = GEN6_PDE_ADDR_ENCODE(pt_addr);
pd_entry |= GEN6_PDE_VALID;
writel(pd_entry, pd_addr + i);
}
readl(pd_addr);
pd_offset = ppgtt->pd_offset;
pd_offset /= 64; /* in cachelines, */
pd_offset <<= 16;
if (INTEL_INFO(dev)->gen == 6) {
uint32_t ecochk, gab_ctl, ecobits;
ecobits = I915_READ(GAC_ECO_BITS);
I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_PPGTT_CACHE64B);
gab_ctl = I915_READ(GAB_CTL);
I915_WRITE(GAB_CTL, gab_ctl | GAB_CTL_CONT_AFTER_PAGEFAULT);
ecochk = I915_READ(GAM_ECOCHK);
I915_WRITE(GAM_ECOCHK, ecochk | ECOCHK_SNB_BIT |
ECOCHK_PPGTT_CACHE64B);
I915_WRITE(GFX_MODE, _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
} else if (INTEL_INFO(dev)->gen >= 7) {
I915_WRITE(GAM_ECOCHK, ECOCHK_PPGTT_CACHE64B);
/* GFX_MODE is per-ring on gen7+ */
}
for_each_ring(ring, dev_priv, i) {
if (INTEL_INFO(dev)->gen >= 7)
I915_WRITE(RING_MODE_GEN7(ring),
_MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
I915_WRITE(RING_PP_DIR_BASE(ring), pd_offset);
}
}
static bool
intel_enable_blt(struct drm_device *dev)
{
if (!HAS_BLT(dev))
return false;
/* The blitter was dysfunctional on early prototypes */
if (IS_GEN6(dev) && dev->pdev->revision < 8) {
DRM_INFO("BLT not supported on this pre-production hardware;"
" graphics performance will be degraded.\n");
return false;
}
return true;
}
int
i915_gem_init_hw(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
int ret;
if (!intel_enable_gtt())
return -EIO;
i915_gem_l3_remap(dev);
i915_gem_init_swizzling(dev);
ret = intel_init_render_ring_buffer(dev);
if (ret)
return ret;
if (HAS_BSD(dev)) {
ret = intel_init_bsd_ring_buffer(dev);
if (ret)
goto cleanup_render_ring;
}
if (intel_enable_blt(dev)) {
ret = intel_init_blt_ring_buffer(dev);
if (ret)
goto cleanup_bsd_ring;
}
dev_priv->next_seqno = 1;
/*
* XXX: There was some w/a described somewhere suggesting loading
* contexts before PPGTT.
*/
i915_gem_context_init(dev);
i915_gem_init_ppgtt(dev);
return 0;
cleanup_bsd_ring:
intel_cleanup_ring_buffer(&dev_priv->ring[VCS]);
cleanup_render_ring:
intel_cleanup_ring_buffer(&dev_priv->ring[RCS]);
return ret;
}
static bool
intel_enable_ppgtt(struct drm_device *dev)
{
if (i915_enable_ppgtt >= 0)
return i915_enable_ppgtt;
#ifdef CONFIG_INTEL_IOMMU
/* Disable ppgtt on SNB if VT-d is on. */
if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped)
return false;
#endif
return true;
}
int i915_gem_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
unsigned long gtt_size, mappable_size;
int ret;
gtt_size = dev_priv->mm.gtt->gtt_total_entries << PAGE_SHIFT;
mappable_size = dev_priv->mm.gtt->gtt_mappable_entries << PAGE_SHIFT;
mutex_lock(&dev->struct_mutex);
if (intel_enable_ppgtt(dev) && HAS_ALIASING_PPGTT(dev)) {
/* PPGTT pdes are stolen from global gtt ptes, so shrink the
* aperture accordingly when using aliasing ppgtt. */
gtt_size -= I915_PPGTT_PD_ENTRIES*PAGE_SIZE;
i915_gem_init_global_gtt(dev, 0, mappable_size, gtt_size);
ret = i915_gem_init_aliasing_ppgtt(dev);
if (ret) {
mutex_unlock(&dev->struct_mutex);
return ret;
}
} else {
/* Let GEM Manage all of the aperture.
*
* However, leave one page at the end still bound to the scratch
* page. There are a number of places where the hardware
* apparently prefetches past the end of the object, and we've
* seen multiple hangs with the GPU head pointer stuck in a
* batchbuffer bound at the last page of the aperture. One page
* should be enough to keep any prefetching inside of the
* aperture.
*/
i915_gem_init_global_gtt(dev, 0, mappable_size,
gtt_size);
}
ret = i915_gem_init_hw(dev);
mutex_unlock(&dev->struct_mutex);
if (ret) {
i915_gem_cleanup_aliasing_ppgtt(dev);
return ret;
}
/* Allow hardware batchbuffers unless told otherwise, but not for KMS. */
if (!drm_core_check_feature(dev, DRIVER_MODESET))
dev_priv->dri1.allow_batchbuffer = 1;
return 0;
}
void
i915_gem_cleanup_ringbuffer(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
struct intel_ring_buffer *ring;
int i;
for_each_ring(ring, dev_priv, i)
intel_cleanup_ring_buffer(ring);
}
int
i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
drm_i915_private_t *dev_priv = dev->dev_private;
int ret;
if (drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
if (atomic_read(&dev_priv->mm.wedged)) {
DRM_ERROR("Reenabling wedged hardware, good luck\n");
atomic_set(&dev_priv->mm.wedged, 0);
}
mutex_lock(&dev->struct_mutex);
dev_priv->mm.suspended = 0;
ret = i915_gem_init_hw(dev);
if (ret != 0) {
mutex_unlock(&dev->struct_mutex);
return ret;
}
BUG_ON(!list_empty(&dev_priv->mm.active_list));
BUG_ON(!list_empty(&dev_priv->mm.inactive_list));
mutex_unlock(&dev->struct_mutex);
ret = drm_irq_install(dev);
if (ret)
goto cleanup_ringbuffer;
return 0;
cleanup_ringbuffer:
mutex_lock(&dev->struct_mutex);
i915_gem_cleanup_ringbuffer(dev);
dev_priv->mm.suspended = 1;
mutex_unlock(&dev->struct_mutex);
return ret;
}
int
i915_gem_leavevt_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
if (drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
drm_irq_uninstall(dev);
return i915_gem_idle(dev);
}
void
i915_gem_lastclose(struct drm_device *dev)
{
int ret;
if (drm_core_check_feature(dev, DRIVER_MODESET))
return;
ret = i915_gem_idle(dev);
if (ret)
DRM_ERROR("failed to idle hardware: %d\n", ret);
}
static void
init_ring_lists(struct intel_ring_buffer *ring)
{
INIT_LIST_HEAD(&ring->active_list);
INIT_LIST_HEAD(&ring->request_list);
}
void
i915_gem_load(struct drm_device *dev)
{
int i;
drm_i915_private_t *dev_priv = dev->dev_private;
INIT_LIST_HEAD(&dev_priv->mm.active_list);
INIT_LIST_HEAD(&dev_priv->mm.inactive_list);
INIT_LIST_HEAD(&dev_priv->mm.fence_list);
INIT_LIST_HEAD(&dev_priv->mm.gtt_list);
for (i = 0; i < I915_NUM_RINGS; i++)
init_ring_lists(&dev_priv->ring[i]);
for (i = 0; i < I915_MAX_NUM_FENCES; i++)
INIT_LIST_HEAD(&dev_priv->fence_regs[i].lru_list);
INIT_DELAYED_WORK(&dev_priv->mm.retire_work,
i915_gem_retire_work_handler);
init_completion(&dev_priv->error_completion);
/* On GEN3 we really need to make sure the ARB C3 LP bit is set */
if (IS_GEN3(dev)) {
I915_WRITE(MI_ARB_STATE,
_MASKED_BIT_ENABLE(MI_ARB_C3_LP_WRITE_ENABLE));
}
dev_priv->relative_constants_mode = I915_EXEC_CONSTANTS_REL_GENERAL;
/* Old X drivers will take 0-2 for front, back, depth buffers */
if (!drm_core_check_feature(dev, DRIVER_MODESET))
dev_priv->fence_reg_start = 3;
if (INTEL_INFO(dev)->gen >= 4 || IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
dev_priv->num_fence_regs = 16;
else
dev_priv->num_fence_regs = 8;
/* Initialize fence registers to zero */
i915_gem_reset_fences(dev);
i915_gem_detect_bit_6_swizzle(dev);
init_waitqueue_head(&dev_priv->pending_flip_queue);
dev_priv->mm.interruptible = true;
dev_priv->mm.inactive_shrinker.shrink = i915_gem_inactive_shrink;
dev_priv->mm.inactive_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&dev_priv->mm.inactive_shrinker);
}
/*
* Create a physically contiguous memory object for this object
* e.g. for cursor + overlay regs
*/
static int i915_gem_init_phys_object(struct drm_device *dev,
int id, int size, int align)
{
drm_i915_private_t *dev_priv = dev->dev_private;
struct drm_i915_gem_phys_object *phys_obj;
int ret;
if (dev_priv->mm.phys_objs[id - 1] || !size)
return 0;
phys_obj = kzalloc(sizeof(struct drm_i915_gem_phys_object), GFP_KERNEL);
if (!phys_obj)
return -ENOMEM;
phys_obj->id = id;
phys_obj->handle = drm_pci_alloc(dev, size, align);
if (!phys_obj->handle) {
ret = -ENOMEM;
goto kfree_obj;
}
#ifdef CONFIG_X86
set_memory_wc((unsigned long)phys_obj->handle->vaddr, phys_obj->handle->size / PAGE_SIZE);
#endif
dev_priv->mm.phys_objs[id - 1] = phys_obj;
return 0;
kfree_obj:
kfree(phys_obj);
return ret;
}
static void i915_gem_free_phys_object(struct drm_device *dev, int id)
{
drm_i915_private_t *dev_priv = dev->dev_private;
struct drm_i915_gem_phys_object *phys_obj;
if (!dev_priv->mm.phys_objs[id - 1])
return;
phys_obj = dev_priv->mm.phys_objs[id - 1];
if (phys_obj->cur_obj) {
i915_gem_detach_phys_object(dev, phys_obj->cur_obj);
}
#ifdef CONFIG_X86
set_memory_wb((unsigned long)phys_obj->handle->vaddr, phys_obj->handle->size / PAGE_SIZE);
#endif
drm_pci_free(dev, phys_obj->handle);
kfree(phys_obj);
dev_priv->mm.phys_objs[id - 1] = NULL;
}
void i915_gem_free_all_phys_object(struct drm_device *dev)
{
int i;
for (i = I915_GEM_PHYS_CURSOR_0; i <= I915_MAX_PHYS_OBJECT; i++)
i915_gem_free_phys_object(dev, i);
}
void i915_gem_detach_phys_object(struct drm_device *dev,
struct drm_i915_gem_object *obj)
{
struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
char *vaddr;
int i;
int page_count;
if (!obj->phys_obj)
return;
vaddr = obj->phys_obj->handle->vaddr;
page_count = obj->base.size / PAGE_SIZE;
for (i = 0; i < page_count; i++) {
struct page *page = shmem_read_mapping_page(mapping, i);
if (!IS_ERR(page)) {
char *dst = kmap_atomic(page);
memcpy(dst, vaddr + i*PAGE_SIZE, PAGE_SIZE);
kunmap_atomic(dst);
drm_clflush_pages(&page, 1);
set_page_dirty(page);
mark_page_accessed(page);
page_cache_release(page);
}
}
intel_gtt_chipset_flush();
obj->phys_obj->cur_obj = NULL;
obj->phys_obj = NULL;
}
int
i915_gem_attach_phys_object(struct drm_device *dev,
struct drm_i915_gem_object *obj,
int id,
int align)
{
struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
drm_i915_private_t *dev_priv = dev->dev_private;
int ret = 0;
int page_count;
int i;
if (id > I915_MAX_PHYS_OBJECT)
return -EINVAL;
if (obj->phys_obj) {
if (obj->phys_obj->id == id)
return 0;
i915_gem_detach_phys_object(dev, obj);
}
/* create a new object */
if (!dev_priv->mm.phys_objs[id - 1]) {
ret = i915_gem_init_phys_object(dev, id,
obj->base.size, align);
if (ret) {
DRM_ERROR("failed to init phys object %d size: %zu\n",
id, obj->base.size);
return ret;
}
}
/* bind to the object */
obj->phys_obj = dev_priv->mm.phys_objs[id - 1];
obj->phys_obj->cur_obj = obj;
page_count = obj->base.size / PAGE_SIZE;
for (i = 0; i < page_count; i++) {
struct page *page;
char *dst, *src;
page = shmem_read_mapping_page(mapping, i);
if (IS_ERR(page))
return PTR_ERR(page);
src = kmap_atomic(page);
dst = obj->phys_obj->handle->vaddr + (i * PAGE_SIZE);
memcpy(dst, src, PAGE_SIZE);
kunmap_atomic(src);
mark_page_accessed(page);
page_cache_release(page);
}
return 0;
}
static int
i915_gem_phys_pwrite(struct drm_device *dev,
struct drm_i915_gem_object *obj,
struct drm_i915_gem_pwrite *args,
struct drm_file *file_priv)
{
void *vaddr = obj->phys_obj->handle->vaddr + args->offset;
char __user *user_data = (char __user *) (uintptr_t) args->data_ptr;
if (__copy_from_user_inatomic_nocache(vaddr, user_data, args->size)) {
unsigned long unwritten;
/* The physical object once assigned is fixed for the lifetime
* of the obj, so we can safely drop the lock and continue
* to access vaddr.
*/
mutex_unlock(&dev->struct_mutex);
unwritten = copy_from_user(vaddr, user_data, args->size);
mutex_lock(&dev->struct_mutex);
if (unwritten)
return -EFAULT;
}
intel_gtt_chipset_flush();
return 0;
}
void i915_gem_release(struct drm_device *dev, struct drm_file *file)
{
struct drm_i915_file_private *file_priv = file->driver_priv;
/* Clean up our request list when the client is going away, so that
* later retire_requests won't dereference our soon-to-be-gone
* file_priv.
*/
spin_lock(&file_priv->mm.lock);
while (!list_empty(&file_priv->mm.request_list)) {
struct drm_i915_gem_request *request;
request = list_first_entry(&file_priv->mm.request_list,
struct drm_i915_gem_request,
client_list);
list_del(&request->client_list);
request->file_priv = NULL;
}
spin_unlock(&file_priv->mm.lock);
}
static int
i915_gpu_is_active(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
return !list_empty(&dev_priv->mm.active_list);
}
static int
i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
{
struct drm_i915_private *dev_priv =
container_of(shrinker,
struct drm_i915_private,
mm.inactive_shrinker);
struct drm_device *dev = dev_priv->dev;
struct drm_i915_gem_object *obj, *next;
int nr_to_scan = sc->nr_to_scan;
int cnt;
if (!mutex_trylock(&dev->struct_mutex))
return 0;
/* "fast-path" to count number of available objects */
if (nr_to_scan == 0) {
cnt = 0;
list_for_each_entry(obj,
&dev_priv->mm.inactive_list,
mm_list)
cnt++;
mutex_unlock(&dev->struct_mutex);
return cnt / 100 * sysctl_vfs_cache_pressure;
}
rescan:
/* first scan for clean buffers */
i915_gem_retire_requests(dev);
list_for_each_entry_safe(obj, next,
&dev_priv->mm.inactive_list,
mm_list) {
if (i915_gem_object_is_purgeable(obj)) {
if (i915_gem_object_unbind(obj) == 0 &&
--nr_to_scan == 0)
break;
}
}
/* second pass, evict/count anything still on the inactive list */
cnt = 0;
list_for_each_entry_safe(obj, next,
&dev_priv->mm.inactive_list,
mm_list) {
if (nr_to_scan &&
i915_gem_object_unbind(obj) == 0)
nr_to_scan--;
else
cnt++;
}
if (nr_to_scan && i915_gpu_is_active(dev)) {
/*
* We are desperate for pages, so as a last resort, wait
* for the GPU to finish and discard whatever we can.
* This has a dramatic impact to reduce the number of
* OOM-killer events whilst running the GPU aggressively.
*/
if (i915_gpu_idle(dev) == 0)
goto rescan;
}
mutex_unlock(&dev->struct_mutex);
return cnt / 100 * sysctl_vfs_cache_pressure;
}