blob: 7dcac3bfb7719a44e7246291e843ee8b8433b76a [file] [log] [blame]
/*
* Copyright © 2008-2015 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 <drm/drmP.h>
#include <drm/drm_vma_manager.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include "i915_gem_clflush.h"
#include "i915_vgpu.h"
#include "i915_trace.h"
#include "intel_drv.h"
#include "intel_frontbuffer.h"
#include "intel_mocs.h"
#include <linux/dma-fence-array.h>
#include <linux/kthread.h>
#include <linux/reservation.h>
#include <linux/shmem_fs.h>
#include <linux/slab.h>
#include <linux/stop_machine.h>
#include <linux/swap.h>
#include <linux/pci.h>
#include <linux/dma-buf.h>
static void i915_gem_flush_free_objects(struct drm_i915_private *i915);
static bool cpu_write_needs_clflush(struct drm_i915_gem_object *obj)
{
if (obj->cache_dirty)
return false;
if (!obj->cache_coherent)
return true;
return obj->pin_display;
}
static int
insert_mappable_node(struct i915_ggtt *ggtt,
struct drm_mm_node *node, u32 size)
{
memset(node, 0, sizeof(*node));
return drm_mm_insert_node_in_range(&ggtt->base.mm, node,
size, 0, I915_COLOR_UNEVICTABLE,
0, ggtt->mappable_end,
DRM_MM_INSERT_LOW);
}
static void
remove_mappable_node(struct drm_mm_node *node)
{
drm_mm_remove_node(node);
}
/* some bookkeeping */
static void i915_gem_info_add_obj(struct drm_i915_private *dev_priv,
u64 size)
{
spin_lock(&dev_priv->mm.object_stat_lock);
dev_priv->mm.object_count++;
dev_priv->mm.object_memory += size;
spin_unlock(&dev_priv->mm.object_stat_lock);
}
static void i915_gem_info_remove_obj(struct drm_i915_private *dev_priv,
u64 size)
{
spin_lock(&dev_priv->mm.object_stat_lock);
dev_priv->mm.object_count--;
dev_priv->mm.object_memory -= size;
spin_unlock(&dev_priv->mm.object_stat_lock);
}
static int
i915_gem_wait_for_error(struct i915_gpu_error *error)
{
int ret;
might_sleep();
/*
* 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_event_interruptible_timeout(error->reset_queue,
!i915_reset_backoff(error),
I915_RESET_TIMEOUT);
if (ret == 0) {
DRM_ERROR("Timed out waiting for the gpu reset to complete\n");
return -EIO;
} else if (ret < 0) {
return ret;
} else {
return 0;
}
}
int i915_mutex_lock_interruptible(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = to_i915(dev);
int ret;
ret = i915_gem_wait_for_error(&dev_priv->gpu_error);
if (ret)
return ret;
ret = mutex_lock_interruptible(&dev->struct_mutex);
if (ret)
return ret;
return 0;
}
int
i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct i915_ggtt *ggtt = &dev_priv->ggtt;
struct drm_i915_gem_get_aperture *args = data;
struct i915_vma *vma;
u64 pinned;
pinned = ggtt->base.reserved;
mutex_lock(&dev->struct_mutex);
list_for_each_entry(vma, &ggtt->base.active_list, vm_link)
if (i915_vma_is_pinned(vma))
pinned += vma->node.size;
list_for_each_entry(vma, &ggtt->base.inactive_list, vm_link)
if (i915_vma_is_pinned(vma))
pinned += vma->node.size;
mutex_unlock(&dev->struct_mutex);
args->aper_size = ggtt->base.total;
args->aper_available_size = args->aper_size - pinned;
return 0;
}
static struct sg_table *
i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
{
struct address_space *mapping = obj->base.filp->f_mapping;
drm_dma_handle_t *phys;
struct sg_table *st;
struct scatterlist *sg;
char *vaddr;
int i;
if (WARN_ON(i915_gem_object_needs_bit17_swizzle(obj)))
return ERR_PTR(-EINVAL);
/* Always aligning to the object size, allows a single allocation
* to handle all possible callers, and given typical object sizes,
* the alignment of the buddy allocation will naturally match.
*/
phys = drm_pci_alloc(obj->base.dev,
obj->base.size,
roundup_pow_of_two(obj->base.size));
if (!phys)
return ERR_PTR(-ENOMEM);
vaddr = phys->vaddr;
for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
struct page *page;
char *src;
page = shmem_read_mapping_page(mapping, i);
if (IS_ERR(page)) {
st = ERR_CAST(page);
goto err_phys;
}
src = kmap_atomic(page);
memcpy(vaddr, src, PAGE_SIZE);
drm_clflush_virt_range(vaddr, PAGE_SIZE);
kunmap_atomic(src);
put_page(page);
vaddr += PAGE_SIZE;
}
i915_gem_chipset_flush(to_i915(obj->base.dev));
st = kmalloc(sizeof(*st), GFP_KERNEL);
if (!st) {
st = ERR_PTR(-ENOMEM);
goto err_phys;
}
if (sg_alloc_table(st, 1, GFP_KERNEL)) {
kfree(st);
st = ERR_PTR(-ENOMEM);
goto err_phys;
}
sg = st->sgl;
sg->offset = 0;
sg->length = obj->base.size;
sg_dma_address(sg) = phys->busaddr;
sg_dma_len(sg) = obj->base.size;
obj->phys_handle = phys;
return st;
err_phys:
drm_pci_free(obj->base.dev, phys);
return st;
}
static void __start_cpu_write(struct drm_i915_gem_object *obj)
{
obj->base.read_domains = I915_GEM_DOMAIN_CPU;
obj->base.write_domain = I915_GEM_DOMAIN_CPU;
if (cpu_write_needs_clflush(obj))
obj->cache_dirty = true;
}
static void
__i915_gem_object_release_shmem(struct drm_i915_gem_object *obj,
struct sg_table *pages,
bool needs_clflush)
{
GEM_BUG_ON(obj->mm.madv == __I915_MADV_PURGED);
if (obj->mm.madv == I915_MADV_DONTNEED)
obj->mm.dirty = false;
if (needs_clflush &&
(obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0 &&
!obj->cache_coherent)
drm_clflush_sg(pages);
__start_cpu_write(obj);
}
static void
i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
struct sg_table *pages)
{
__i915_gem_object_release_shmem(obj, pages, false);
if (obj->mm.dirty) {
struct address_space *mapping = obj->base.filp->f_mapping;
char *vaddr = obj->phys_handle->vaddr;
int i;
for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
struct page *page;
char *dst;
page = shmem_read_mapping_page(mapping, i);
if (IS_ERR(page))
continue;
dst = kmap_atomic(page);
drm_clflush_virt_range(vaddr, PAGE_SIZE);
memcpy(dst, vaddr, PAGE_SIZE);
kunmap_atomic(dst);
set_page_dirty(page);
if (obj->mm.madv == I915_MADV_WILLNEED)
mark_page_accessed(page);
put_page(page);
vaddr += PAGE_SIZE;
}
obj->mm.dirty = false;
}
sg_free_table(pages);
kfree(pages);
drm_pci_free(obj->base.dev, obj->phys_handle);
}
static void
i915_gem_object_release_phys(struct drm_i915_gem_object *obj)
{
i915_gem_object_unpin_pages(obj);
}
static const struct drm_i915_gem_object_ops i915_gem_phys_ops = {
.get_pages = i915_gem_object_get_pages_phys,
.put_pages = i915_gem_object_put_pages_phys,
.release = i915_gem_object_release_phys,
};
static const struct drm_i915_gem_object_ops i915_gem_object_ops;
int i915_gem_object_unbind(struct drm_i915_gem_object *obj)
{
struct i915_vma *vma;
LIST_HEAD(still_in_list);
int ret;
lockdep_assert_held(&obj->base.dev->struct_mutex);
/* Closed vma are removed from the obj->vma_list - but they may
* still have an active binding on the object. To remove those we
* must wait for all rendering to complete to the object (as unbinding
* must anyway), and retire the requests.
*/
ret = i915_gem_object_wait(obj,
I915_WAIT_INTERRUPTIBLE |
I915_WAIT_LOCKED |
I915_WAIT_ALL,
MAX_SCHEDULE_TIMEOUT,
NULL);
if (ret)
return ret;
i915_gem_retire_requests(to_i915(obj->base.dev));
while ((vma = list_first_entry_or_null(&obj->vma_list,
struct i915_vma,
obj_link))) {
list_move_tail(&vma->obj_link, &still_in_list);
ret = i915_vma_unbind(vma);
if (ret)
break;
}
list_splice(&still_in_list, &obj->vma_list);
return ret;
}
static long
i915_gem_object_wait_fence(struct dma_fence *fence,
unsigned int flags,
long timeout,
struct intel_rps_client *rps)
{
struct drm_i915_gem_request *rq;
BUILD_BUG_ON(I915_WAIT_INTERRUPTIBLE != 0x1);
if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
return timeout;
if (!dma_fence_is_i915(fence))
return dma_fence_wait_timeout(fence,
flags & I915_WAIT_INTERRUPTIBLE,
timeout);
rq = to_request(fence);
if (i915_gem_request_completed(rq))
goto out;
/* This client is about to stall waiting for the GPU. In many cases
* this is undesirable and limits the throughput of the system, as
* many clients cannot continue processing user input/output whilst
* blocked. RPS autotuning may take tens of milliseconds to respond
* to the GPU load and thus incurs additional latency for the client.
* We can circumvent that by promoting the GPU frequency to maximum
* before we wait. This makes the GPU throttle up much more quickly
* (good for benchmarks and user experience, e.g. window animations),
* but at a cost of spending more power processing the workload
* (bad for battery). Not all clients even want their results
* immediately and for them we should just let the GPU select its own
* frequency to maximise efficiency. To prevent a single client from
* forcing the clocks too high for the whole system, we only allow
* each client to waitboost once in a busy period.
*/
if (rps) {
if (INTEL_GEN(rq->i915) >= 6)
gen6_rps_boost(rq->i915, rps, rq->emitted_jiffies);
else
rps = NULL;
}
timeout = i915_wait_request(rq, flags, timeout);
out:
if (flags & I915_WAIT_LOCKED && i915_gem_request_completed(rq))
i915_gem_request_retire_upto(rq);
if (rps && i915_gem_request_global_seqno(rq) == intel_engine_last_submit(rq->engine)) {
/* The GPU is now idle and this client has stalled.
* Since no other client has submitted a request in the
* meantime, assume that this client is the only one
* supplying work to the GPU but is unable to keep that
* work supplied because it is waiting. Since the GPU is
* then never kept fully busy, RPS autoclocking will
* keep the clocks relatively low, causing further delays.
* Compensate by giving the synchronous client credit for
* a waitboost next time.
*/
spin_lock(&rq->i915->rps.client_lock);
list_del_init(&rps->link);
spin_unlock(&rq->i915->rps.client_lock);
}
return timeout;
}
static long
i915_gem_object_wait_reservation(struct reservation_object *resv,
unsigned int flags,
long timeout,
struct intel_rps_client *rps)
{
unsigned int seq = __read_seqcount_begin(&resv->seq);
struct dma_fence *excl;
bool prune_fences = false;
if (flags & I915_WAIT_ALL) {
struct dma_fence **shared;
unsigned int count, i;
int ret;
ret = reservation_object_get_fences_rcu(resv,
&excl, &count, &shared);
if (ret)
return ret;
for (i = 0; i < count; i++) {
timeout = i915_gem_object_wait_fence(shared[i],
flags, timeout,
rps);
if (timeout < 0)
break;
dma_fence_put(shared[i]);
}
for (; i < count; i++)
dma_fence_put(shared[i]);
kfree(shared);
prune_fences = count && timeout >= 0;
} else {
excl = reservation_object_get_excl_rcu(resv);
}
if (excl && timeout >= 0) {
timeout = i915_gem_object_wait_fence(excl, flags, timeout, rps);
prune_fences = timeout >= 0;
}
dma_fence_put(excl);
/* Oportunistically prune the fences iff we know they have *all* been
* signaled and that the reservation object has not been changed (i.e.
* no new fences have been added).
*/
if (prune_fences && !__read_seqcount_retry(&resv->seq, seq)) {
if (reservation_object_trylock(resv)) {
if (!__read_seqcount_retry(&resv->seq, seq))
reservation_object_add_excl_fence(resv, NULL);
reservation_object_unlock(resv);
}
}
return timeout;
}
static void __fence_set_priority(struct dma_fence *fence, int prio)
{
struct drm_i915_gem_request *rq;
struct intel_engine_cs *engine;
if (!dma_fence_is_i915(fence))
return;
rq = to_request(fence);
engine = rq->engine;
if (!engine->schedule)
return;
engine->schedule(rq, prio);
}
static void fence_set_priority(struct dma_fence *fence, int prio)
{
/* Recurse once into a fence-array */
if (dma_fence_is_array(fence)) {
struct dma_fence_array *array = to_dma_fence_array(fence);
int i;
for (i = 0; i < array->num_fences; i++)
__fence_set_priority(array->fences[i], prio);
} else {
__fence_set_priority(fence, prio);
}
}
int
i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
unsigned int flags,
int prio)
{
struct dma_fence *excl;
if (flags & I915_WAIT_ALL) {
struct dma_fence **shared;
unsigned int count, i;
int ret;
ret = reservation_object_get_fences_rcu(obj->resv,
&excl, &count, &shared);
if (ret)
return ret;
for (i = 0; i < count; i++) {
fence_set_priority(shared[i], prio);
dma_fence_put(shared[i]);
}
kfree(shared);
} else {
excl = reservation_object_get_excl_rcu(obj->resv);
}
if (excl) {
fence_set_priority(excl, prio);
dma_fence_put(excl);
}
return 0;
}
/**
* Waits for rendering to the object to be completed
* @obj: i915 gem object
* @flags: how to wait (under a lock, for all rendering or just for writes etc)
* @timeout: how long to wait
* @rps: client (user process) to charge for any waitboosting
*/
int
i915_gem_object_wait(struct drm_i915_gem_object *obj,
unsigned int flags,
long timeout,
struct intel_rps_client *rps)
{
might_sleep();
#if IS_ENABLED(CONFIG_LOCKDEP)
GEM_BUG_ON(debug_locks &&
!!lockdep_is_held(&obj->base.dev->struct_mutex) !=
!!(flags & I915_WAIT_LOCKED));
#endif
GEM_BUG_ON(timeout < 0);
timeout = i915_gem_object_wait_reservation(obj->resv,
flags, timeout,
rps);
return timeout < 0 ? timeout : 0;
}
static struct intel_rps_client *to_rps_client(struct drm_file *file)
{
struct drm_i915_file_private *fpriv = file->driver_priv;
return &fpriv->rps;
}
int
i915_gem_object_attach_phys(struct drm_i915_gem_object *obj,
int align)
{
int ret;
if (align > obj->base.size)
return -EINVAL;
if (obj->ops == &i915_gem_phys_ops)
return 0;
if (obj->mm.madv != I915_MADV_WILLNEED)
return -EFAULT;
if (obj->base.filp == NULL)
return -EINVAL;
ret = i915_gem_object_unbind(obj);
if (ret)
return ret;
__i915_gem_object_put_pages(obj, I915_MM_NORMAL);
if (obj->mm.pages)
return -EBUSY;
GEM_BUG_ON(obj->ops != &i915_gem_object_ops);
obj->ops = &i915_gem_phys_ops;
ret = i915_gem_object_pin_pages(obj);
if (ret)
goto err_xfer;
return 0;
err_xfer:
obj->ops = &i915_gem_object_ops;
return ret;
}
static int
i915_gem_phys_pwrite(struct drm_i915_gem_object *obj,
struct drm_i915_gem_pwrite *args,
struct drm_file *file)
{
void *vaddr = obj->phys_handle->vaddr + args->offset;
char __user *user_data = u64_to_user_ptr(args->data_ptr);
/* We manually control the domain here and pretend that it
* remains coherent i.e. in the GTT domain, like shmem_pwrite.
*/
intel_fb_obj_invalidate(obj, ORIGIN_CPU);
if (copy_from_user(vaddr, user_data, args->size))
return -EFAULT;
drm_clflush_virt_range(vaddr, args->size);
i915_gem_chipset_flush(to_i915(obj->base.dev));
intel_fb_obj_flush(obj, ORIGIN_CPU);
return 0;
}
void *i915_gem_object_alloc(struct drm_i915_private *dev_priv)
{
return kmem_cache_zalloc(dev_priv->objects, GFP_KERNEL);
}
void i915_gem_object_free(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
kmem_cache_free(dev_priv->objects, obj);
}
static int
i915_gem_create(struct drm_file *file,
struct drm_i915_private *dev_priv,
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_object_create(dev_priv, size);
if (IS_ERR(obj))
return PTR_ERR(obj);
ret = drm_gem_handle_create(file, &obj->base, &handle);
/* drop reference from allocate - handle holds it now */
i915_gem_object_put(obj);
if (ret)
return ret;
*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 * DIV_ROUND_UP(args->bpp, 8), 64);
args->size = args->pitch * args->height;
return i915_gem_create(file, to_i915(dev),
args->size, &args->handle);
}
static bool gpu_write_needs_clflush(struct drm_i915_gem_object *obj)
{
return !(obj->cache_level == I915_CACHE_NONE ||
obj->cache_level == I915_CACHE_WT);
}
/**
* Creates a new mm object and returns a handle to it.
* @dev: drm device pointer
* @data: ioctl data blob
* @file: drm file pointer
*/
int
i915_gem_create_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct drm_i915_gem_create *args = data;
i915_gem_flush_free_objects(dev_priv);
return i915_gem_create(file, dev_priv,
args->size, &args->handle);
}
static inline enum fb_op_origin
fb_write_origin(struct drm_i915_gem_object *obj, unsigned int domain)
{
return (domain == I915_GEM_DOMAIN_GTT ?
obj->frontbuffer_ggtt_origin : ORIGIN_CPU);
}
static void
flush_write_domain(struct drm_i915_gem_object *obj, unsigned int flush_domains)
{
struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
if (!(obj->base.write_domain & flush_domains))
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.
*
* We also have to wait a bit for the writes to land from the GTT.
* An uncached read (i.e. mmio) seems to be ideal for the round-trip
* timing. This issue has only been observed when switching quickly
* between GTT writes and CPU reads from inside the kernel on recent hw,
* and it appears to only affect discrete GTT blocks (i.e. on LLC
* system agents we cannot reproduce this behaviour).
*/
wmb();
switch (obj->base.write_domain) {
case I915_GEM_DOMAIN_GTT:
if (INTEL_GEN(dev_priv) >= 6 && !HAS_LLC(dev_priv)) {
if (intel_runtime_pm_get_if_in_use(dev_priv)) {
spin_lock_irq(&dev_priv->uncore.lock);
POSTING_READ_FW(RING_ACTHD(dev_priv->engine[RCS]->mmio_base));
spin_unlock_irq(&dev_priv->uncore.lock);
intel_runtime_pm_put(dev_priv);
}
}
intel_fb_obj_flush(obj,
fb_write_origin(obj, I915_GEM_DOMAIN_GTT));
break;
case I915_GEM_DOMAIN_CPU:
i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC);
break;
case I915_GEM_DOMAIN_RENDER:
if (gpu_write_needs_clflush(obj))
obj->cache_dirty = true;
break;
}
obj->base.write_domain = 0;
}
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;
}
/*
* Pins the specified object's pages and synchronizes the object with
* GPU accesses. Sets needs_clflush to non-zero if the caller should
* flush the object from the CPU cache.
*/
int i915_gem_obj_prepare_shmem_read(struct drm_i915_gem_object *obj,
unsigned int *needs_clflush)
{
int ret;
lockdep_assert_held(&obj->base.dev->struct_mutex);
*needs_clflush = 0;
if (!i915_gem_object_has_struct_page(obj))
return -ENODEV;
ret = i915_gem_object_wait(obj,
I915_WAIT_INTERRUPTIBLE |
I915_WAIT_LOCKED,
MAX_SCHEDULE_TIMEOUT,
NULL);
if (ret)
return ret;
ret = i915_gem_object_pin_pages(obj);
if (ret)
return ret;
if (obj->cache_coherent || !static_cpu_has(X86_FEATURE_CLFLUSH)) {
ret = i915_gem_object_set_to_cpu_domain(obj, false);
if (ret)
goto err_unpin;
else
goto out;
}
flush_write_domain(obj, ~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_dirty &&
!(obj->base.read_domains & I915_GEM_DOMAIN_CPU))
*needs_clflush = CLFLUSH_BEFORE;
out:
/* return with the pages pinned */
return 0;
err_unpin:
i915_gem_object_unpin_pages(obj);
return ret;
}
int i915_gem_obj_prepare_shmem_write(struct drm_i915_gem_object *obj,
unsigned int *needs_clflush)
{
int ret;
lockdep_assert_held(&obj->base.dev->struct_mutex);
*needs_clflush = 0;
if (!i915_gem_object_has_struct_page(obj))
return -ENODEV;
ret = i915_gem_object_wait(obj,
I915_WAIT_INTERRUPTIBLE |
I915_WAIT_LOCKED |
I915_WAIT_ALL,
MAX_SCHEDULE_TIMEOUT,
NULL);
if (ret)
return ret;
ret = i915_gem_object_pin_pages(obj);
if (ret)
return ret;
if (obj->cache_coherent || !static_cpu_has(X86_FEATURE_CLFLUSH)) {
ret = i915_gem_object_set_to_cpu_domain(obj, true);
if (ret)
goto err_unpin;
else
goto out;
}
flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
/* If we're not in the cpu write domain, set ourself into the
* gtt write domain and manually flush cachelines (as 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_dirty) {
*needs_clflush |= CLFLUSH_AFTER;
/*
* Same trick applies to invalidate partially written
* cachelines read before writing.
*/
if (!(obj->base.read_domains & I915_GEM_DOMAIN_CPU))
*needs_clflush |= CLFLUSH_BEFORE;
}
out:
intel_fb_obj_invalidate(obj, ORIGIN_CPU);
obj->mm.dirty = true;
/* return with the pages pinned */
return 0;
err_unpin:
i915_gem_object_unpin_pages(obj);
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 offset, int 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 + offset, length,
page_do_bit17_swizzling);
if (page_do_bit17_swizzling)
ret = __copy_to_user_swizzled(user_data, vaddr, offset, length);
else
ret = __copy_to_user(user_data, vaddr + offset, length);
kunmap(page);
return ret ? - EFAULT : 0;
}
static int
shmem_pread(struct page *page, int offset, int length, char __user *user_data,
bool page_do_bit17_swizzling, bool needs_clflush)
{
int ret;
ret = -ENODEV;
if (!page_do_bit17_swizzling) {
char *vaddr = kmap_atomic(page);
if (needs_clflush)
drm_clflush_virt_range(vaddr + offset, length);
ret = __copy_to_user_inatomic(user_data, vaddr + offset, length);
kunmap_atomic(vaddr);
}
if (ret == 0)
return 0;
return shmem_pread_slow(page, offset, length, user_data,
page_do_bit17_swizzling, needs_clflush);
}
static int
i915_gem_shmem_pread(struct drm_i915_gem_object *obj,
struct drm_i915_gem_pread *args)
{
char __user *user_data;
u64 remain;
unsigned int obj_do_bit17_swizzling;
unsigned int needs_clflush;
unsigned int idx, offset;
int ret;
obj_do_bit17_swizzling = 0;
if (i915_gem_object_needs_bit17_swizzle(obj))
obj_do_bit17_swizzling = BIT(17);
ret = mutex_lock_interruptible(&obj->base.dev->struct_mutex);
if (ret)
return ret;
ret = i915_gem_obj_prepare_shmem_read(obj, &needs_clflush);
mutex_unlock(&obj->base.dev->struct_mutex);
if (ret)
return ret;
remain = args->size;
user_data = u64_to_user_ptr(args->data_ptr);
offset = offset_in_page(args->offset);
for (idx = args->offset >> PAGE_SHIFT; remain; idx++) {
struct page *page = i915_gem_object_get_page(obj, idx);
int length;
length = remain;
if (offset + length > PAGE_SIZE)
length = PAGE_SIZE - offset;
ret = shmem_pread(page, offset, length, user_data,
page_to_phys(page) & obj_do_bit17_swizzling,
needs_clflush);
if (ret)
break;
remain -= length;
user_data += length;
offset = 0;
}
i915_gem_obj_finish_shmem_access(obj);
return ret;
}
static inline bool
gtt_user_read(struct io_mapping *mapping,
loff_t base, int offset,
char __user *user_data, int length)
{
void *vaddr;
unsigned long unwritten;
/* We can use the cpu mem copy function because this is X86. */
vaddr = (void __force *)io_mapping_map_atomic_wc(mapping, base);
unwritten = __copy_to_user_inatomic(user_data, vaddr + offset, length);
io_mapping_unmap_atomic(vaddr);
if (unwritten) {
vaddr = (void __force *)
io_mapping_map_wc(mapping, base, PAGE_SIZE);
unwritten = copy_to_user(user_data, vaddr + offset, length);
io_mapping_unmap(vaddr);
}
return unwritten;
}
static int
i915_gem_gtt_pread(struct drm_i915_gem_object *obj,
const struct drm_i915_gem_pread *args)
{
struct drm_i915_private *i915 = to_i915(obj->base.dev);
struct i915_ggtt *ggtt = &i915->ggtt;
struct drm_mm_node node;
struct i915_vma *vma;
void __user *user_data;
u64 remain, offset;
int ret;
ret = mutex_lock_interruptible(&i915->drm.struct_mutex);
if (ret)
return ret;
intel_runtime_pm_get(i915);
vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0,
PIN_MAPPABLE | PIN_NONBLOCK);
if (!IS_ERR(vma)) {
node.start = i915_ggtt_offset(vma);
node.allocated = false;
ret = i915_vma_put_fence(vma);
if (ret) {
i915_vma_unpin(vma);
vma = ERR_PTR(ret);
}
}
if (IS_ERR(vma)) {
ret = insert_mappable_node(ggtt, &node, PAGE_SIZE);
if (ret)
goto out_unlock;
GEM_BUG_ON(!node.allocated);
}
ret = i915_gem_object_set_to_gtt_domain(obj, false);
if (ret)
goto out_unpin;
mutex_unlock(&i915->drm.struct_mutex);
user_data = u64_to_user_ptr(args->data_ptr);
remain = args->size;
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
*/
u32 page_base = node.start;
unsigned page_offset = offset_in_page(offset);
unsigned page_length = PAGE_SIZE - page_offset;
page_length = remain < page_length ? remain : page_length;
if (node.allocated) {
wmb();
ggtt->base.insert_page(&ggtt->base,
i915_gem_object_get_dma_address(obj, offset >> PAGE_SHIFT),
node.start, I915_CACHE_NONE, 0);
wmb();
} else {
page_base += offset & PAGE_MASK;
}
if (gtt_user_read(&ggtt->mappable, page_base, page_offset,
user_data, page_length)) {
ret = -EFAULT;
break;
}
remain -= page_length;
user_data += page_length;
offset += page_length;
}
mutex_lock(&i915->drm.struct_mutex);
out_unpin:
if (node.allocated) {
wmb();
ggtt->base.clear_range(&ggtt->base,
node.start, node.size);
remove_mappable_node(&node);
} else {
i915_vma_unpin(vma);
}
out_unlock:
intel_runtime_pm_put(i915);
mutex_unlock(&i915->drm.struct_mutex);
return ret;
}
/**
* Reads data from the object referenced by handle.
* @dev: drm device pointer
* @data: ioctl data blob
* @file: drm file pointer
*
* 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;
if (args->size == 0)
return 0;
if (!access_ok(VERIFY_WRITE,
u64_to_user_ptr(args->data_ptr),
args->size))
return -EFAULT;
obj = i915_gem_object_lookup(file, args->handle);
if (!obj)
return -ENOENT;
/* Bounds check source. */
if (range_overflows_t(u64, args->offset, args->size, obj->base.size)) {
ret = -EINVAL;
goto out;
}
trace_i915_gem_object_pread(obj, args->offset, args->size);
ret = i915_gem_object_wait(obj,
I915_WAIT_INTERRUPTIBLE,
MAX_SCHEDULE_TIMEOUT,
to_rps_client(file));
if (ret)
goto out;
ret = i915_gem_object_pin_pages(obj);
if (ret)
goto out;
ret = i915_gem_shmem_pread(obj, args);
if (ret == -EFAULT || ret == -ENODEV)
ret = i915_gem_gtt_pread(obj, args);
i915_gem_object_unpin_pages(obj);
out:
i915_gem_object_put(obj);
return ret;
}
/* This is the fast write path which cannot handle
* page faults in the source data
*/
static inline bool
ggtt_write(struct io_mapping *mapping,
loff_t base, int offset,
char __user *user_data, int length)
{
void *vaddr;
unsigned long unwritten;
/* We can use the cpu mem copy function because this is X86. */
vaddr = (void __force *)io_mapping_map_atomic_wc(mapping, base);
unwritten = __copy_from_user_inatomic_nocache(vaddr + offset,
user_data, length);
io_mapping_unmap_atomic(vaddr);
if (unwritten) {
vaddr = (void __force *)
io_mapping_map_wc(mapping, base, PAGE_SIZE);
unwritten = copy_from_user(vaddr + offset, user_data, length);
io_mapping_unmap(vaddr);
}
return unwritten;
}
/**
* This is the fast pwrite path, where we copy the data directly from the
* user into the GTT, uncached.
* @obj: i915 GEM object
* @args: pwrite arguments structure
*/
static int
i915_gem_gtt_pwrite_fast(struct drm_i915_gem_object *obj,
const struct drm_i915_gem_pwrite *args)
{
struct drm_i915_private *i915 = to_i915(obj->base.dev);
struct i915_ggtt *ggtt = &i915->ggtt;
struct drm_mm_node node;
struct i915_vma *vma;
u64 remain, offset;
void __user *user_data;
int ret;
ret = mutex_lock_interruptible(&i915->drm.struct_mutex);
if (ret)
return ret;
intel_runtime_pm_get(i915);
vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0,
PIN_MAPPABLE | PIN_NONBLOCK);
if (!IS_ERR(vma)) {
node.start = i915_ggtt_offset(vma);
node.allocated = false;
ret = i915_vma_put_fence(vma);
if (ret) {
i915_vma_unpin(vma);
vma = ERR_PTR(ret);
}
}
if (IS_ERR(vma)) {
ret = insert_mappable_node(ggtt, &node, PAGE_SIZE);
if (ret)
goto out_unlock;
GEM_BUG_ON(!node.allocated);
}
ret = i915_gem_object_set_to_gtt_domain(obj, true);
if (ret)
goto out_unpin;
mutex_unlock(&i915->drm.struct_mutex);
intel_fb_obj_invalidate(obj, ORIGIN_CPU);
user_data = u64_to_user_ptr(args->data_ptr);
offset = args->offset;
remain = args->size;
while (remain) {
/* Operation in this page
*
* page_base = page offset within aperture
* page_offset = offset within page
* page_length = bytes to copy for this page
*/
u32 page_base = node.start;
unsigned int page_offset = offset_in_page(offset);
unsigned int page_length = PAGE_SIZE - page_offset;
page_length = remain < page_length ? remain : page_length;
if (node.allocated) {
wmb(); /* flush the write before we modify the GGTT */
ggtt->base.insert_page(&ggtt->base,
i915_gem_object_get_dma_address(obj, offset >> PAGE_SHIFT),
node.start, I915_CACHE_NONE, 0);
wmb(); /* flush modifications to the GGTT (insert_page) */
} else {
page_base += offset & PAGE_MASK;
}
/* 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 the object is non-shmem backed, we retry again with the
* path that handles page fault.
*/
if (ggtt_write(&ggtt->mappable, page_base, page_offset,
user_data, page_length)) {
ret = -EFAULT;
break;
}
remain -= page_length;
user_data += page_length;
offset += page_length;
}
intel_fb_obj_flush(obj, ORIGIN_CPU);
mutex_lock(&i915->drm.struct_mutex);
out_unpin:
if (node.allocated) {
wmb();
ggtt->base.clear_range(&ggtt->base,
node.start, node.size);
remove_mappable_node(&node);
} else {
i915_vma_unpin(vma);
}
out_unlock:
intel_runtime_pm_put(i915);
mutex_unlock(&i915->drm.struct_mutex);
return ret;
}
static int
shmem_pwrite_slow(struct page *page, int offset, int 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 + offset, length,
page_do_bit17_swizzling);
if (page_do_bit17_swizzling)
ret = __copy_from_user_swizzled(vaddr, offset, user_data,
length);
else
ret = __copy_from_user(vaddr + offset, user_data, length);
if (needs_clflush_after)
shmem_clflush_swizzled_range(vaddr + offset, length,
page_do_bit17_swizzling);
kunmap(page);
return ret ? -EFAULT : 0;
}
/* 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(struct page *page, int offset, int len, char __user *user_data,
bool page_do_bit17_swizzling,
bool needs_clflush_before,
bool needs_clflush_after)
{
int ret;
ret = -ENODEV;
if (!page_do_bit17_swizzling) {
char *vaddr = kmap_atomic(page);
if (needs_clflush_before)
drm_clflush_virt_range(vaddr + offset, len);
ret = __copy_from_user_inatomic(vaddr + offset, user_data, len);
if (needs_clflush_after)
drm_clflush_virt_range(vaddr + offset, len);
kunmap_atomic(vaddr);
}
if (ret == 0)
return ret;
return shmem_pwrite_slow(page, offset, len, user_data,
page_do_bit17_swizzling,
needs_clflush_before,
needs_clflush_after);
}
static int
i915_gem_shmem_pwrite(struct drm_i915_gem_object *obj,
const struct drm_i915_gem_pwrite *args)
{
struct drm_i915_private *i915 = to_i915(obj->base.dev);
void __user *user_data;
u64 remain;
unsigned int obj_do_bit17_swizzling;
unsigned int partial_cacheline_write;
unsigned int needs_clflush;
unsigned int offset, idx;
int ret;
ret = mutex_lock_interruptible(&i915->drm.struct_mutex);
if (ret)
return ret;
ret = i915_gem_obj_prepare_shmem_write(obj, &needs_clflush);
mutex_unlock(&i915->drm.struct_mutex);
if (ret)
return ret;
obj_do_bit17_swizzling = 0;
if (i915_gem_object_needs_bit17_swizzle(obj))
obj_do_bit17_swizzling = BIT(17);
/* 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 = 0;
if (needs_clflush & CLFLUSH_BEFORE)
partial_cacheline_write = boot_cpu_data.x86_clflush_size - 1;
user_data = u64_to_user_ptr(args->data_ptr);
remain = args->size;
offset = offset_in_page(args->offset);
for (idx = args->offset >> PAGE_SHIFT; remain; idx++) {
struct page *page = i915_gem_object_get_page(obj, idx);
int length;
length = remain;
if (offset + length > PAGE_SIZE)
length = PAGE_SIZE - offset;
ret = shmem_pwrite(page, offset, length, user_data,
page_to_phys(page) & obj_do_bit17_swizzling,
(offset | length) & partial_cacheline_write,
needs_clflush & CLFLUSH_AFTER);
if (ret)
break;
remain -= length;
user_data += length;
offset = 0;
}
intel_fb_obj_flush(obj, ORIGIN_CPU);
i915_gem_obj_finish_shmem_access(obj);
return ret;
}
/**
* Writes data to the object referenced by handle.
* @dev: drm device
* @data: ioctl data blob
* @file: drm file
*
* 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,
u64_to_user_ptr(args->data_ptr),
args->size))
return -EFAULT;
obj = i915_gem_object_lookup(file, args->handle);
if (!obj)
return -ENOENT;
/* Bounds check destination. */
if (range_overflows_t(u64, args->offset, args->size, obj->base.size)) {
ret = -EINVAL;
goto err;
}
trace_i915_gem_object_pwrite(obj, args->offset, args->size);
ret = -ENODEV;
if (obj->ops->pwrite)
ret = obj->ops->pwrite(obj, args);
if (ret != -ENODEV)
goto err;
ret = i915_gem_object_wait(obj,
I915_WAIT_INTERRUPTIBLE |
I915_WAIT_ALL,
MAX_SCHEDULE_TIMEOUT,
to_rps_client(file));
if (ret)
goto err;
ret = i915_gem_object_pin_pages(obj);
if (ret)
goto err;
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 (!i915_gem_object_has_struct_page(obj) ||
cpu_write_needs_clflush(obj))
/* 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.
*/
ret = i915_gem_gtt_pwrite_fast(obj, args);
if (ret == -EFAULT || ret == -ENOSPC) {
if (obj->phys_handle)
ret = i915_gem_phys_pwrite(obj, args, file);
else
ret = i915_gem_shmem_pwrite(obj, args);
}
i915_gem_object_unpin_pages(obj);
err:
i915_gem_object_put(obj);
return ret;
}
static void i915_gem_object_bump_inactive_ggtt(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *i915;
struct list_head *list;
struct i915_vma *vma;
list_for_each_entry(vma, &obj->vma_list, obj_link) {
if (!i915_vma_is_ggtt(vma))
break;
if (i915_vma_is_active(vma))
continue;
if (!drm_mm_node_allocated(&vma->node))
continue;
list_move_tail(&vma->vm_link, &vma->vm->inactive_list);
}
i915 = to_i915(obj->base.dev);
list = obj->bind_count ? &i915->mm.bound_list : &i915->mm.unbound_list;
list_move_tail(&obj->global_link, list);
}
/**
* Called when user space prepares to use an object with the CPU, either
* through the mmap ioctl's mapping or a GTT mapping.
* @dev: drm device
* @data: ioctl data blob
* @file: drm file
*/
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 err;
/* Only handle setting domains to types used by the CPU. */
if ((write_domain | 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;
obj = i915_gem_object_lookup(file, args->handle);
if (!obj)
return -ENOENT;
/* Try to flush the object off the GPU without holding the lock.
* We will repeat the flush holding the lock in the normal manner
* to catch cases where we are gazumped.
*/
err = i915_gem_object_wait(obj,
I915_WAIT_INTERRUPTIBLE |
(write_domain ? I915_WAIT_ALL : 0),
MAX_SCHEDULE_TIMEOUT,
to_rps_client(file));
if (err)
goto out;
/* Flush and acquire obj->pages so that we are coherent through
* direct access in memory with previous cached writes through
* shmemfs and that our cache domain tracking remains valid.
* For example, if the obj->filp was moved to swap without us
* being notified and releasing the pages, we would mistakenly
* continue to assume that the obj remained out of the CPU cached
* domain.
*/
err = i915_gem_object_pin_pages(obj);
if (err)
goto out;
err = i915_mutex_lock_interruptible(dev);
if (err)
goto out_unpin;
if (read_domains & I915_GEM_DOMAIN_WC)
err = i915_gem_object_set_to_wc_domain(obj, write_domain);
else if (read_domains & I915_GEM_DOMAIN_GTT)
err = i915_gem_object_set_to_gtt_domain(obj, write_domain);
else
err = i915_gem_object_set_to_cpu_domain(obj, write_domain);
/* And bump the LRU for this access */
i915_gem_object_bump_inactive_ggtt(obj);
mutex_unlock(&dev->struct_mutex);
if (write_domain != 0)
intel_fb_obj_invalidate(obj,
fb_write_origin(obj, write_domain));
out_unpin:
i915_gem_object_unpin_pages(obj);
out:
i915_gem_object_put(obj);
return err;
}
/**
* Called when user space has done writes to this buffer
* @dev: drm device
* @data: ioctl data blob
* @file: drm file
*/
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;
obj = i915_gem_object_lookup(file, args->handle);
if (!obj)
return -ENOENT;
/* Pinned buffers may be scanout, so flush the cache */
i915_gem_object_flush_if_display(obj);
i915_gem_object_put(obj);
return 0;
}
/**
* i915_gem_mmap_ioctl - Maps the contents of an object, returning the address
* it is mapped to.
* @dev: drm device
* @data: ioctl data blob
* @file: drm file
*
* While the mapping holds a reference on the contents of the object, it doesn't
* imply a ref on the object itself.
*
* IMPORTANT:
*
* DRM driver writers who look a this function as an example for how to do GEM
* mmap support, please don't implement mmap support like here. The modern way
* to implement DRM mmap support is with an mmap offset ioctl (like
* i915_gem_mmap_gtt) and then using the mmap syscall on the DRM fd directly.
* That way debug tooling like valgrind will understand what's going on, hiding
* the mmap call in a driver private ioctl will break that. The i915 driver only
* does cpu mmaps this way because we didn't know better.
*/
int
i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_mmap *args = data;
struct drm_i915_gem_object *obj;
unsigned long addr;
if (args->flags & ~(I915_MMAP_WC))
return -EINVAL;
if (args->flags & I915_MMAP_WC && !boot_cpu_has(X86_FEATURE_PAT))
return -ENODEV;
obj = i915_gem_object_lookup(file, args->handle);
if (!obj)
return -ENOENT;
/* prime objects have no backing filp to GEM mmap
* pages from.
*/
if (!obj->base.filp) {
i915_gem_object_put(obj);
return -EINVAL;
}
addr = vm_mmap(obj->base.filp, 0, args->size,
PROT_READ | PROT_WRITE, MAP_SHARED,
args->offset);
if (args->flags & I915_MMAP_WC) {
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
if (down_write_killable(&mm->mmap_sem)) {
i915_gem_object_put(obj);
return -EINTR;
}
vma = find_vma(mm, addr);
if (vma)
vma->vm_page_prot =
pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
else
addr = -ENOMEM;
up_write(&mm->mmap_sem);
/* This may race, but that's ok, it only gets set */
WRITE_ONCE(obj->frontbuffer_ggtt_origin, ORIGIN_CPU);
}
i915_gem_object_put(obj);
if (IS_ERR((void *)addr))
return addr;
args->addr_ptr = (uint64_t) addr;
return 0;
}
static unsigned int tile_row_pages(struct drm_i915_gem_object *obj)
{
return i915_gem_object_get_tile_row_size(obj) >> PAGE_SHIFT;
}
/**
* i915_gem_mmap_gtt_version - report the current feature set for GTT mmaps
*
* A history of the GTT mmap interface:
*
* 0 - Everything had to fit into the GTT. Both parties of a memcpy had to
* aligned and suitable for fencing, and still fit into the available
* mappable space left by the pinned display objects. A classic problem
* we called the page-fault-of-doom where we would ping-pong between
* two objects that could not fit inside the GTT and so the memcpy
* would page one object in at the expense of the other between every
* single byte.
*
* 1 - Objects can be any size, and have any compatible fencing (X Y, or none
* as set via i915_gem_set_tiling() [DRM_I915_GEM_SET_TILING]). If the
* object is too large for the available space (or simply too large
* for the mappable aperture!), a view is created instead and faulted
* into userspace. (This view is aligned and sized appropriately for
* fenced access.)
*
* 2 - Recognise WC as a separate cache domain so that we can flush the
* delayed writes via GTT before performing direct access via WC.
*
* Restrictions:
*
* * snoopable objects cannot be accessed via the GTT. It can cause machine
* hangs on some architectures, corruption on others. An attempt to service
* a GTT page fault from a snoopable object will generate a SIGBUS.
*
* * the object must be able to fit into RAM (physical memory, though no
* limited to the mappable aperture).
*
*
* Caveats:
*
* * a new GTT page fault will synchronize rendering from the GPU and flush
* all data to system memory. Subsequent access will not be synchronized.
*
* * all mappings are revoked on runtime device suspend.
*
* * there are only 8, 16 or 32 fence registers to share between all users
* (older machines require fence register for display and blitter access
* as well). Contention of the fence registers will cause the previous users
* to be unmapped and any new access will generate new page faults.
*
* * running out of memory while servicing a fault may generate a SIGBUS,
* rather than the expected SIGSEGV.
*/
int i915_gem_mmap_gtt_version(void)
{
return 2;
}
static inline struct i915_ggtt_view
compute_partial_view(struct drm_i915_gem_object *obj,
pgoff_t page_offset,
unsigned int chunk)
{
struct i915_ggtt_view view;
if (i915_gem_object_is_tiled(obj))
chunk = roundup(chunk, tile_row_pages(obj));
view.type = I915_GGTT_VIEW_PARTIAL;
view.partial.offset = rounddown(page_offset, chunk);
view.partial.size =
min_t(unsigned int, chunk,
(obj->base.size >> PAGE_SHIFT) - view.partial.offset);
/* If the partial covers the entire object, just create a normal VMA. */
if (chunk >= obj->base.size >> PAGE_SHIFT)
view.type = I915_GGTT_VIEW_NORMAL;
return view;
}
/**
* i915_gem_fault - fault a page into the GTT
* @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.
*
* The current feature set supported by i915_gem_fault() and thus GTT mmaps
* is exposed via I915_PARAM_MMAP_GTT_VERSION (see i915_gem_mmap_gtt_version).
*/
int i915_gem_fault(struct vm_fault *vmf)
{
#define MIN_CHUNK_PAGES ((1 << 20) >> PAGE_SHIFT) /* 1 MiB */
struct vm_area_struct *area = vmf->vma;
struct drm_i915_gem_object *obj = to_intel_bo(area->vm_private_data);
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *dev_priv = to_i915(dev);
struct i915_ggtt *ggtt = &dev_priv->ggtt;
bool write = !!(vmf->flags & FAULT_FLAG_WRITE);
struct i915_vma *vma;
pgoff_t page_offset;
unsigned int flags;
int ret;
/* We don't use vmf->pgoff since that has the fake offset */
page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT;
trace_i915_gem_object_fault(obj, page_offset, true, write);
/* Try to flush the object off the GPU first without holding the lock.
* Upon acquiring the lock, we will perform our sanity checks and then
* repeat the flush holding the lock in the normal manner to catch cases
* where we are gazumped.
*/
ret = i915_gem_object_wait(obj,
I915_WAIT_INTERRUPTIBLE,
MAX_SCHEDULE_TIMEOUT,
NULL);
if (ret)
goto err;
ret = i915_gem_object_pin_pages(obj);
if (ret)
goto err;
intel_runtime_pm_get(dev_priv);
ret = i915_mutex_lock_interruptible(dev);
if (ret)
goto err_rpm;
/* Access to snoopable pages through the GTT is incoherent. */
if (obj->cache_level != I915_CACHE_NONE && !HAS_LLC(dev_priv)) {
ret = -EFAULT;
goto err_unlock;
}
/* If the object is smaller than a couple of partial vma, it is
* not worth only creating a single partial vma - we may as well
* clear enough space for the full object.
*/
flags = PIN_MAPPABLE;
if (obj->base.size > 2 * MIN_CHUNK_PAGES << PAGE_SHIFT)
flags |= PIN_NONBLOCK | PIN_NONFAULT;
/* Now pin it into the GTT as needed */
vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, flags);
if (IS_ERR(vma)) {
/* Use a partial view if it is bigger than available space */
struct i915_ggtt_view view =
compute_partial_view(obj, page_offset, MIN_CHUNK_PAGES);
/* Userspace is now writing through an untracked VMA, abandon
* all hope that the hardware is able to track future writes.
*/
obj->frontbuffer_ggtt_origin = ORIGIN_CPU;
vma = i915_gem_object_ggtt_pin(obj, &view, 0, 0, PIN_MAPPABLE);
}
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto err_unlock;
}
ret = i915_gem_object_set_to_gtt_domain(obj, write);
if (ret)
goto err_unpin;
ret = i915_vma_get_fence(vma);
if (ret)
goto err_unpin;
/* Mark as being mmapped into userspace for later revocation */
assert_rpm_wakelock_held(dev_priv);
if (list_empty(&obj->userfault_link))
list_add(&obj->userfault_link, &dev_priv->mm.userfault_list);
/* Finally, remap it using the new GTT offset */
ret = remap_io_mapping(area,
area->vm_start + (vma->ggtt_view.partial.offset << PAGE_SHIFT),
(ggtt->mappable_base + vma->node.start) >> PAGE_SHIFT,
min_t(u64, vma->size, area->vm_end - area->vm_start),
&ggtt->mappable);
err_unpin:
__i915_vma_unpin(vma);
err_unlock:
mutex_unlock(&dev->struct_mutex);
err_rpm:
intel_runtime_pm_put(dev_priv);
i915_gem_object_unpin_pages(obj);
err:
switch (ret) {
case -EIO:
/*
* We eat errors when the gpu is terminally wedged to avoid
* userspace unduly crashing (gl has no provisions for mmaps to
* fail). But any other -EIO isn't ours (e.g. swap in failure)
* and so needs to be reported.
*/
if (!i915_terminally_wedged(&dev_priv->gpu_error)) {
ret = VM_FAULT_SIGBUS;
break;
}
case -EAGAIN:
/*
* EAGAIN means the gpu is hung and we'll wait for the error
* handler to reset everything when re-faulting in
* i915_mutex_lock_interruptible.
*/
case 0:
case -ERESTARTSYS:
case -EINTR:
case -EBUSY:
/*
* EBUSY is ok: this just means that another thread
* already did the job.
*/
ret = VM_FAULT_NOPAGE;
break;
case -ENOMEM:
ret = VM_FAULT_OOM;
break;
case -ENOSPC:
case -EFAULT:
ret = VM_FAULT_SIGBUS;
break;
default:
WARN_ONCE(ret, "unhandled error in i915_gem_fault: %i\n", ret);
ret = VM_FAULT_SIGBUS;
break;
}
return ret;
}
/**
* 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)
{
struct drm_i915_private *i915 = to_i915(obj->base.dev);
/* Serialisation between user GTT access and our code depends upon
* revoking the CPU's PTE whilst the mutex is held. The next user
* pagefault then has to wait until we release the mutex.
*
* Note that RPM complicates somewhat by adding an additional
* requirement that operations to the GGTT be made holding the RPM
* wakeref.
*/
lockdep_assert_held(&i915->drm.struct_mutex);
intel_runtime_pm_get(i915);
if (list_empty(&obj->userfault_link))
goto out;
list_del_init(&obj->userfault_link);
drm_vma_node_unmap(&obj->base.vma_node,
obj->base.dev->anon_inode->i_mapping);
/* Ensure that the CPU's PTE are revoked and there are not outstanding
* memory transactions from userspace before we return. The TLB
* flushing implied above by changing the PTE above *should* be
* sufficient, an extra barrier here just provides us with a bit
* of paranoid documentation about our requirement to serialise
* memory writes before touching registers / GSM.
*/
wmb();
out:
intel_runtime_pm_put(i915);
}
void i915_gem_runtime_suspend(struct drm_i915_private *dev_priv)
{
struct drm_i915_gem_object *obj, *on;
int i;
/*
* Only called during RPM suspend. All users of the userfault_list
* must be holding an RPM wakeref to ensure that this can not
* run concurrently with themselves (and use the struct_mutex for
* protection between themselves).
*/
list_for_each_entry_safe(obj, on,
&dev_priv->mm.userfault_list, userfault_link) {
list_del_init(&obj->userfault_link);
drm_vma_node_unmap(&obj->base.vma_node,
obj->base.dev->anon_inode->i_mapping);
}
/* The fence will be lost when the device powers down. If any were
* in use by hardware (i.e. they are pinned), we should not be powering
* down! All other fences will be reacquired by the user upon waking.
*/
for (i = 0; i < dev_priv->num_fence_regs; i++) {
struct drm_i915_fence_reg *reg = &dev_priv->fence_regs[i];
/* Ideally we want to assert that the fence register is not
* live at this point (i.e. that no piece of code will be
* trying to write through fence + GTT, as that both violates
* our tracking of activity and associated locking/barriers,
* but also is illegal given that the hw is powered down).
*
* Previously we used reg->pin_count as a "liveness" indicator.
* That is not sufficient, and we need a more fine-grained
* tool if we want to have a sanity check here.
*/
if (!reg->vma)
continue;
GEM_BUG_ON(!list_empty(&reg->vma->obj->userfault_link));
reg->dirty = true;
}
}
static int i915_gem_object_create_mmap_offset(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
int err;
err = drm_gem_create_mmap_offset(&obj->base);
if (likely(!err))
return 0;
/* Attempt to reap some mmap space from dead objects */
do {
err = i915_gem_wait_for_idle(dev_priv, I915_WAIT_INTERRUPTIBLE);
if (err)
break;
i915_gem_drain_freed_objects(dev_priv);
err = drm_gem_create_mmap_offset(&obj->base);
if (!err)
break;
} while (flush_delayed_work(&dev_priv->gt.retire_work));
return err;
}
static void i915_gem_object_free_mmap_offset(struct drm_i915_gem_object *obj)
{
drm_gem_free_mmap_offset(&obj->base);
}
int
i915_gem_mmap_gtt(struct drm_file *file,
struct drm_device *dev,
uint32_t handle,
uint64_t *offset)
{
struct drm_i915_gem_object *obj;
int ret;
obj = i915_gem_object_lookup(file, handle);
if (!obj)
return -ENOENT;
ret = i915_gem_object_create_mmap_offset(obj);
if (ret == 0)
*offset = drm_vma_node_offset_addr(&obj->base.vma_node);
i915_gem_object_put(obj);
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);
}
/* Immediately discard the backing storage */
static void
i915_gem_object_truncate(struct drm_i915_gem_object *obj)
{
i915_gem_object_free_mmap_offset(obj);
if (obj->base.filp == NULL)
return;
/* 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*.
*/
shmem_truncate_range(file_inode(obj->base.filp), 0, (loff_t)-1);
obj->mm.madv = __I915_MADV_PURGED;
obj->mm.pages = ERR_PTR(-EFAULT);
}
/* Try to discard unwanted pages */
void __i915_gem_object_invalidate(struct drm_i915_gem_object *obj)
{
struct address_space *mapping;
lockdep_assert_held(&obj->mm.lock);
GEM_BUG_ON(obj->mm.pages);
switch (obj->mm.madv) {
case I915_MADV_DONTNEED:
i915_gem_object_truncate(obj);
case __I915_MADV_PURGED:
return;
}
if (obj->base.filp == NULL)
return;
mapping = obj->base.filp->f_mapping,
invalidate_mapping_pages(mapping, 0, (loff_t)-1);
}
static void
i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj,
struct sg_table *pages)
{
struct sgt_iter sgt_iter;
struct page *page;
__i915_gem_object_release_shmem(obj, pages, true);
i915_gem_gtt_finish_pages(obj, pages);
if (i915_gem_object_needs_bit17_swizzle(obj))
i915_gem_object_save_bit_17_swizzle(obj, pages);
for_each_sgt_page(page, sgt_iter, pages) {
if (obj->mm.dirty)
set_page_dirty(page);
if (obj->mm.madv == I915_MADV_WILLNEED)
mark_page_accessed(page);
put_page(page);
}
obj->mm.dirty = false;
sg_free_table(pages);
kfree(pages);
}
static void __i915_gem_object_reset_page_iter(struct drm_i915_gem_object *obj)
{
struct radix_tree_iter iter;
void **slot;
radix_tree_for_each_slot(slot, &obj->mm.get_page.radix, &iter, 0)
radix_tree_delete(&obj->mm.get_page.radix, iter.index);
}
void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
enum i915_mm_subclass subclass)
{
struct sg_table *pages;
if (i915_gem_object_has_pinned_pages(obj))
return;
GEM_BUG_ON(obj->bind_count);
if (!READ_ONCE(obj->mm.pages))
return;
/* May be called by shrinker from within get_pages() (on another bo) */
mutex_lock_nested(&obj->mm.lock, subclass);
if (unlikely(atomic_read(&obj->mm.pages_pin_count)))
goto unlock;
/* ->put_pages might need to allocate memory for the bit17 swizzle
* array, hence protect them from being reaped by removing them from gtt
* lists early. */
pages = fetch_and_zero(&obj->mm.pages);
GEM_BUG_ON(!pages);
if (obj->mm.mapping) {
void *ptr;
ptr = page_mask_bits(obj->mm.mapping);
if (is_vmalloc_addr(ptr))
vunmap(ptr);
else
kunmap(kmap_to_page(ptr));
obj->mm.mapping = NULL;
}
__i915_gem_object_reset_page_iter(obj);
if (!IS_ERR(pages))
obj->ops->put_pages(obj, pages);
unlock:
mutex_unlock(&obj->mm.lock);
}
static bool i915_sg_trim(struct sg_table *orig_st)
{
struct sg_table new_st;
struct scatterlist *sg, *new_sg;
unsigned int i;
if (orig_st->nents == orig_st->orig_nents)
return false;
if (sg_alloc_table(&new_st, orig_st->nents, GFP_KERNEL | __GFP_NOWARN))
return false;
new_sg = new_st.sgl;
for_each_sg(orig_st->sgl, sg, orig_st->nents, i) {
sg_set_page(new_sg, sg_page(sg), sg->length, 0);
/* called before being DMA mapped, no need to copy sg->dma_* */
new_sg = sg_next(new_sg);
}
GEM_BUG_ON(new_sg); /* Should walk exactly nents and hit the end */
sg_free_table(orig_st);
*orig_st = new_st;
return true;
}
static struct sg_table *
i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
const unsigned long page_count = obj->base.size / PAGE_SIZE;
unsigned long i;
struct address_space *mapping;
struct sg_table *st;
struct scatterlist *sg;
struct sgt_iter sgt_iter;
struct page *page;
unsigned long last_pfn = 0; /* suppress gcc warning */
unsigned int max_segment;
gfp_t noreclaim;
int ret;
/* 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
*/
GEM_BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS);
GEM_BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS);
max_segment = swiotlb_max_segment();
if (!max_segment)
max_segment = rounddown(UINT_MAX, PAGE_SIZE);
st = kmalloc(sizeof(*st), GFP_KERNEL);
if (st == NULL)
return ERR_PTR(-ENOMEM);
rebuild_st:
if (sg_alloc_table(st, page_count, GFP_KERNEL)) {
kfree(st);
return ERR_PTR(-ENOMEM);
}
/* Get the list of pages out of our struct file. They'll be pinned
* at this point until we release them.
*
* Fail silently without starting the shrinker
*/
mapping = obj->base.filp->f_mapping;
noreclaim = mapping_gfp_constraint(mapping, ~__GFP_RECLAIM);
noreclaim |= __GFP_NORETRY | __GFP_NOWARN;
sg = st->sgl;
st->nents = 0;
for (i = 0; i < page_count; i++) {
const unsigned int shrink[] = {
I915_SHRINK_BOUND | I915_SHRINK_UNBOUND | I915_SHRINK_PURGEABLE,
0,
}, *s = shrink;
gfp_t gfp = noreclaim;
do {
page = shmem_read_mapping_page_gfp(mapping, i, gfp);
if (likely(!IS_ERR(page)))
break;
if (!*s) {
ret = PTR_ERR(page);
goto err_sg;
}
i915_gem_shrink(dev_priv, 2 * page_count, *s++);
cond_resched();
/* We've tried hard to allocate the memory by reaping
* our own buffer, now let the real VM do its job and
* go down in flames if truly OOM.
*
* However, since graphics tend to be disposable,
* defer the oom here by reporting the ENOMEM back
* to userspace.
*/
if (!*s) {
/* reclaim and warn, but no oom */
gfp = mapping_gfp_mask(mapping);
/* Our bo are always dirty and so we require
* kswapd to reclaim our pages (direct reclaim
* does not effectively begin pageout of our
* buffers on its own). However, direct reclaim
* only waits for kswapd when under allocation
* congestion. So as a result __GFP_RECLAIM is
* unreliable and fails to actually reclaim our
* dirty pages -- unless you try over and over
* again with !__GFP_NORETRY. However, we still
* want to fail this allocation rather than
* trigger the out-of-memory killer and for
* this we want the future __GFP_MAYFAIL.
*/
}
} while (1);
if (!i ||
sg->length >= max_segment ||
page_to_pfn(page) != last_pfn + 1) {
if (i)
sg = sg_next(sg);
st->nents++;
sg_set_page(sg, page, PAGE_SIZE, 0);
} else {
sg->length += PAGE_SIZE;
}
last_pfn = page_to_pfn(page);
/* Check that the i965g/gm workaround works. */
WARN_ON((gfp & __GFP_DMA32) && (last_pfn >= 0x00100000UL));
}
if (sg) /* loop terminated early; short sg table */
sg_mark_end(sg);
/* Trim unused sg entries to avoid wasting memory. */
i915_sg_trim(st);
ret = i915_gem_gtt_prepare_pages(obj, st);
if (ret) {
/* DMA remapping failed? One possible cause is that
* it could not reserve enough large entries, asking
* for PAGE_SIZE chunks instead may be helpful.
*/
if (max_segment > PAGE_SIZE) {
for_each_sgt_page(page, sgt_iter, st)
put_page(page);
sg_free_table(st);
max_segment = PAGE_SIZE;
goto rebuild_st;
} else {
dev_warn(&dev_priv->drm.pdev->dev,
"Failed to DMA remap %lu pages\n",
page_count);
goto err_pages;
}
}
if (i915_gem_object_needs_bit17_swizzle(obj))
i915_gem_object_do_bit_17_swizzle(obj, st);
return st;
err_sg:
sg_mark_end(sg);
err_pages:
for_each_sgt_page(page, sgt_iter, st)
put_page(page);
sg_free_table(st);
kfree(st);
/* shmemfs first checks if there is enough memory to allocate the page
* and reports ENOSPC should there be insufficient, along with the usual
* ENOMEM for a genuine allocation failure.
*
* We use ENOSPC in our driver to mean that we have run out of aperture
* space and so want to translate the error from shmemfs back to our
* usual understanding of ENOMEM.
*/
if (ret == -ENOSPC)
ret = -ENOMEM;
return ERR_PTR(ret);
}
void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj,
struct sg_table *pages)
{
lockdep_assert_held(&obj->mm.lock);
obj->mm.get_page.sg_pos = pages->sgl;
obj->mm.get_page.sg_idx = 0;
obj->mm.pages = pages;
if (i915_gem_object_is_tiled(obj) &&
to_i915(obj->base.dev)->quirks & QUIRK_PIN_SWIZZLED_PAGES) {
GEM_BUG_ON(obj->mm.quirked);
__i915_gem_object_pin_pages(obj);
obj->mm.quirked = true;
}
}
static int ____i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
{
struct sg_table *pages;
GEM_BUG_ON(i915_gem_object_has_pinned_pages(obj));
if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) {
DRM_DEBUG("Attempting to obtain a purgeable object\n");
return -EFAULT;
}
pages = obj->ops->get_pages(obj);
if (unlikely(IS_ERR(pages)))
return PTR_ERR(pages);
__i915_gem_object_set_pages(obj, pages);
return 0;
}
/* Ensure that the associated pages are gathered from the backing storage
* and pinned into our object. i915_gem_object_pin_pages() may be called
* multiple times before they are released by a single call to
* i915_gem_object_unpin_pages() - once the pages are no longer referenced
* either as a result of memory pressure (reaping pages under the shrinker)
* or as the object is itself released.
*/
int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
{
int err;
err = mutex_lock_interruptible(&obj->mm.lock);
if (err)
return err;
if (unlikely(IS_ERR_OR_NULL(obj->mm.pages))) {
err = ____i915_gem_object_get_pages(obj);
if (err)
goto unlock;
smp_mb__before_atomic();
}
atomic_inc(&obj->mm.pages_pin_count);
unlock:
mutex_unlock(&obj->mm.lock);
return err;
}
/* The 'mapping' part of i915_gem_object_pin_map() below */
static void *i915_gem_object_map(const struct drm_i915_gem_object *obj,
enum i915_map_type type)
{
unsigned long n_pages = obj->base.size >> PAGE_SHIFT;
struct sg_table *sgt = obj->mm.pages;
struct sgt_iter sgt_iter;
struct page *page;
struct page *stack_pages[32];
struct page **pages = stack_pages;
unsigned long i = 0;
pgprot_t pgprot;
void *addr;
/* A single page can always be kmapped */
if (n_pages == 1 && type == I915_MAP_WB)
return kmap(sg_page(sgt->sgl));
if (n_pages > ARRAY_SIZE(stack_pages)) {
/* Too big for stack -- allocate temporary array instead */
pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_TEMPORARY);
if (!pages)
return NULL;
}
for_each_sgt_page(page, sgt_iter, sgt)
pages[i++] = page;
/* Check that we have the expected number of pages */
GEM_BUG_ON(i != n_pages);
switch (type) {
case I915_MAP_WB:
pgprot = PAGE_KERNEL;
break;
case I915_MAP_WC:
pgprot = pgprot_writecombine(PAGE_KERNEL_IO);
break;
}
addr = vmap(pages, n_pages, 0, pgprot);
if (pages != stack_pages)
kvfree(pages);
return addr;
}
/* get, pin, and map the pages of the object into kernel space */
void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
enum i915_map_type type)
{
enum i915_map_type has_type;
bool pinned;
void *ptr;
int ret;
GEM_BUG_ON(!i915_gem_object_has_struct_page(obj));
ret = mutex_lock_interruptible(&obj->mm.lock);
if (ret)
return ERR_PTR(ret);
pinned = true;
if (!atomic_inc_not_zero(&obj->mm.pages_pin_count)) {
if (unlikely(IS_ERR_OR_NULL(obj->mm.pages))) {
ret = ____i915_gem_object_get_pages(obj);
if (ret)
goto err_unlock;
smp_mb__before_atomic();
}
atomic_inc(&obj->mm.pages_pin_count);
pinned = false;
}
GEM_BUG_ON(!obj->mm.pages);
ptr = page_unpack_bits(obj->mm.mapping, &has_type);
if (ptr && has_type != type) {
if (pinned) {
ret = -EBUSY;
goto err_unpin;
}
if (is_vmalloc_addr(ptr))
vunmap(ptr);
else
kunmap(kmap_to_page(ptr));
ptr = obj->mm.mapping = NULL;
}
if (!ptr) {
ptr = i915_gem_object_map(obj, type);
if (!ptr) {
ret = -ENOMEM;
goto err_unpin;
}
obj->mm.mapping = page_pack_bits(ptr, type);
}
out_unlock:
mutex_unlock(&obj->mm.lock);
return ptr;
err_unpin:
atomic_dec(&obj->mm.pages_pin_count);
err_unlock:
ptr = ERR_PTR(ret);
goto out_unlock;
}
static int
i915_gem_object_pwrite_gtt(struct drm_i915_gem_object *obj,
const struct drm_i915_gem_pwrite *arg)
{
struct address_space *mapping = obj->base.filp->f_mapping;
char __user *user_data = u64_to_user_ptr(arg->data_ptr);
u64 remain, offset;
unsigned int pg;
/* Before we instantiate/pin the backing store for our use, we
* can prepopulate the shmemfs filp efficiently using a write into
* the pagecache. We avoid the penalty of instantiating all the
* pages, important if the user is just writing to a few and never
* uses the object on the GPU, and using a direct write into shmemfs
* allows it to avoid the cost of retrieving a page (either swapin
* or clearing-before-use) before it is overwritten.
*/
if (READ_ONCE(obj->mm.pages))
return -ENODEV;
/* Before the pages are instantiated the object is treated as being
* in the CPU domain. The pages will be clflushed as required before
* use, and we can freely write into the pages directly. If userspace
* races pwrite with any other operation; corruption will ensue -
* that is userspace's prerogative!
*/
remain = arg->size;
offset = arg->offset;
pg = offset_in_page(offset);
do {
unsigned int len, unwritten;
struct page *page;
void *data, *vaddr;
int err;
len = PAGE_SIZE - pg;
if (len > remain)
len = remain;
err = pagecache_write_begin(obj->base.filp, mapping,
offset, len, 0,
&page, &data);
if (err < 0)
return err;
vaddr = kmap(page);
unwritten = copy_from_user(vaddr + pg, user_data, len);
kunmap(page);
err = pagecache_write_end(obj->base.filp, mapping,
offset, len, len - unwritten,
page, data);
if (err < 0)
return err;
if (unwritten)
return -EFAULT;
remain -= len;
user_data += len;
offset += len;
pg = 0;
} while (remain);
return 0;
}
static bool ban_context(const struct i915_gem_context *ctx)
{
return (i915_gem_context_is_bannable(ctx) &&
ctx->ban_score >= CONTEXT_SCORE_BAN_THRESHOLD);
}
static void i915_gem_context_mark_guilty(struct i915_gem_context *ctx)
{
ctx->guilty_count++;
ctx->ban_score += CONTEXT_SCORE_GUILTY;
if (ban_context(ctx))
i915_gem_context_set_banned(ctx);
DRM_DEBUG_DRIVER("context %s marked guilty (score %d) banned? %s\n",
ctx->name, ctx->ban_score,
yesno(i915_gem_context_is_banned(ctx)));
if (!i915_gem_context_is_banned(ctx) || IS_ERR_OR_NULL(ctx->file_priv))
return;
ctx->file_priv->context_bans++;
DRM_DEBUG_DRIVER("client %s has had %d context banned\n",
ctx->name, ctx->file_priv->context_bans);
}
static void i915_gem_context_mark_innocent(struct i915_gem_context *ctx)
{
ctx->active_count++;
}
struct drm_i915_gem_request *
i915_gem_find_active_request(struct intel_engine_cs *engine)
{
struct drm_i915_gem_request *request, *active = NULL;
unsigned long flags;
/* We are called by the error capture and reset at a random
* point in time. In particular, note that neither is crucially
* ordered with an interrupt. After a hang, the GPU is dead and we
* assume that no more writes can happen (we waited long enough for
* all writes that were in transaction to be flushed) - adding an
* extra delay for a recent interrupt is pointless. Hence, we do
* not need an engine->irq_seqno_barrier() before the seqno reads.
*/
spin_lock_irqsave(&engine->timeline->lock, flags);
list_for_each_entry(request, &engine->timeline->requests, link) {
if (__i915_gem_request_completed(request,
request->global_seqno))
continue;
GEM_BUG_ON(request->engine != engine);
GEM_BUG_ON(test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
&request->fence.flags));
active = request;
break;
}
spin_unlock_irqrestore(&engine->timeline->lock, flags);
return active;
}
static bool engine_stalled(struct intel_engine_cs *engine)
{
if (!engine->hangcheck.stalled)
return false;
/* Check for possible seqno movement after hang declaration */
if (engine->hangcheck.seqno != intel_engine_get_seqno(engine)) {
DRM_DEBUG_DRIVER("%s pardoned\n", engine->name);
return false;
}
return true;
}
int i915_gem_reset_prepare(struct drm_i915_private *dev_priv)
{
struct intel_engine_cs *engine;
enum intel_engine_id id;
int err = 0;
/* Ensure irq handler finishes, and not run again. */
for_each_engine(engine, dev_priv, id) {
struct drm_i915_gem_request *request;
/* Prevent the signaler thread from updating the request
* state (by calling dma_fence_signal) as we are processing
* the reset. The write from the GPU of the seqno is
* asynchronous and the signaler thread may see a different
* value to us and declare the request complete, even though
* the reset routine have picked that request as the active
* (incomplete) request. This conflict is not handled
* gracefully!
*/
kthread_park(engine->breadcrumbs.signaler);
/* Prevent request submission to the hardware until we have
* completed the reset in i915_gem_reset_finish(). If a request
* is completed by one engine, it may then queue a request
* to a second via its engine->irq_tasklet *just* as we are
* calling engine->init_hw() and also writing the ELSP.
* Turning off the engine->irq_tasklet until the reset is over
* prevents the race.
*/
tasklet_kill(&engine->irq_tasklet);
tasklet_disable(&engine->irq_tasklet);
if (engine->irq_seqno_barrier)
engine->irq_seqno_barrier(engine);
if (engine_stalled(engine)) {
request = i915_gem_find_active_request(engine);
if (request && request->fence.error == -EIO)
err = -EIO; /* Previous reset failed! */
}
}
i915_gem_revoke_fences(dev_priv);
return err;
}
static void skip_request(struct drm_i915_gem_request *request)
{
void *vaddr = request->ring->vaddr;
u32 head;
/* As this request likely depends on state from the lost
* context, clear out all the user operations leaving the
* breadcrumb at the end (so we get the fence notifications).
*/
head = request->head;
if (request->postfix < head) {
memset(vaddr + head, 0, request->ring->size - head);
head = 0;
}
memset(vaddr + head, 0, request->postfix - head);
dma_fence_set_error(&request->fence, -EIO);
}