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/*
* SPDX-License-Identifier: MIT
*
* Copyright © 2014-2016 Intel Corporation
*/
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/swiotlb.h>
#include "i915_drv.h"
#include "i915_gem.h"
#include "i915_gem_object.h"
#include "i915_scatterlist.h"
#include "i915_utils.h"
#define QUIET (__GFP_NORETRY | __GFP_NOWARN)
#define MAYFAIL (__GFP_RETRY_MAYFAIL | __GFP_NOWARN)
static void internal_free_pages(struct sg_table *st)
{
struct scatterlist *sg;
for (sg = st->sgl; sg; sg = __sg_next(sg)) {
if (sg_page(sg))
__free_pages(sg_page(sg), get_order(sg->length));
}
sg_free_table(st);
kfree(st);
}
static int i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *i915 = to_i915(obj->base.dev);
struct sg_table *st;
struct scatterlist *sg;
unsigned int sg_page_sizes;
unsigned int npages;
int max_order;
gfp_t gfp;
max_order = MAX_ORDER;
#ifdef CONFIG_SWIOTLB
if (is_swiotlb_active()) {
unsigned int max_segment;
max_segment = swiotlb_max_segment();
if (max_segment) {
max_segment = max_t(unsigned int, max_segment,
PAGE_SIZE) >> PAGE_SHIFT;
max_order = min(max_order, ilog2(max_segment));
}
}
#endif
gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE;
if (IS_I965GM(i915) || IS_I965G(i915)) {
/* 965gm cannot relocate objects above 4GiB. */
gfp &= ~__GFP_HIGHMEM;
gfp |= __GFP_DMA32;
}
create_st:
st = kmalloc(sizeof(*st), GFP_KERNEL);
if (!st)
return -ENOMEM;
npages = obj->base.size / PAGE_SIZE;
if (sg_alloc_table(st, npages, GFP_KERNEL)) {
kfree(st);
return -ENOMEM;
}
sg = st->sgl;
st->nents = 0;
sg_page_sizes = 0;
do {
int order = min(fls(npages) - 1, max_order);
struct page *page;
do {
page = alloc_pages(gfp | (order ? QUIET : MAYFAIL),
order);
if (page)
break;
if (!order--)
goto err;
/* Limit subsequent allocations as well */
max_order = order;
} while (1);
sg_set_page(sg, page, PAGE_SIZE << order, 0);
sg_page_sizes |= PAGE_SIZE << order;
st->nents++;
npages -= 1 << order;
if (!npages) {
sg_mark_end(sg);
break;
}
sg = __sg_next(sg);
} while (1);
if (i915_gem_gtt_prepare_pages(obj, st)) {
/* Failed to dma-map try again with single page sg segments */
if (get_order(st->sgl->length)) {
internal_free_pages(st);
max_order = 0;
goto create_st;
}
goto err;
}
__i915_gem_object_set_pages(obj, st, sg_page_sizes);
return 0;
err:
sg_set_page(sg, NULL, 0, 0);
sg_mark_end(sg);
internal_free_pages(st);
return -ENOMEM;
}
static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj,
struct sg_table *pages)
{
i915_gem_gtt_finish_pages(obj, pages);
internal_free_pages(pages);
obj->mm.dirty = false;
}
static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {
.name = "i915_gem_object_internal",
.flags = I915_GEM_OBJECT_IS_SHRINKABLE,
.get_pages = i915_gem_object_get_pages_internal,
.put_pages = i915_gem_object_put_pages_internal,
};
/**
* i915_gem_object_create_internal: create an object with volatile pages
* @i915: the i915 device
* @size: the size in bytes of backing storage to allocate for the object
*
* Creates a new object that wraps some internal memory for private use.
* This object is not backed by swappable storage, and as such its contents
* are volatile and only valid whilst pinned. If the object is reaped by the
* shrinker, its pages and data will be discarded. Equally, it is not a full
* GEM object and so not valid for access from userspace. This makes it useful
* for hardware interfaces like ringbuffers (which are pinned from the time
* the request is written to the time the hardware stops accessing it), but
* not for contexts (which need to be preserved when not active for later
* reuse). Note that it is not cleared upon allocation.
*/
struct drm_i915_gem_object *
i915_gem_object_create_internal(struct drm_i915_private *i915,
phys_addr_t size)
{
static struct lock_class_key lock_class;
struct drm_i915_gem_object *obj;
unsigned int cache_level;
GEM_BUG_ON(!size);
GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
if (overflows_type(size, obj->base.size))
return ERR_PTR(-E2BIG);
obj = i915_gem_object_alloc();
if (!obj)
return ERR_PTR(-ENOMEM);
drm_gem_private_object_init(&i915->drm, &obj->base, size);
i915_gem_object_init(obj, &i915_gem_object_internal_ops, &lock_class,
I915_BO_ALLOC_STRUCT_PAGE);
/*
* Mark the object as volatile, such that the pages are marked as
* dontneed whilst they are still pinned. As soon as they are unpinned
* they are allowed to be reaped by the shrinker, and the caller is
* expected to repopulate - the contents of this object are only valid
* whilst active and pinned.
*/
i915_gem_object_set_volatile(obj);
obj->read_domains = I915_GEM_DOMAIN_CPU;
obj->write_domain = I915_GEM_DOMAIN_CPU;
cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
i915_gem_object_set_cache_coherency(obj, cache_level);
return obj;
}
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