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Regard whitespace Rev 4075 → Rev 4569

/drivers/video/drm/vmwgfx/vmwgfx_buffer.c
40,6 → 40,10
static uint32_t sys_placement_flags = TTM_PL_FLAG_SYSTEM |
TTM_PL_FLAG_CACHED;
 
static uint32_t sys_ne_placement_flags = TTM_PL_FLAG_SYSTEM |
TTM_PL_FLAG_CACHED |
TTM_PL_FLAG_NO_EVICT;
 
static uint32_t gmr_placement_flags = VMW_PL_FLAG_GMR |
TTM_PL_FLAG_CACHED;
 
47,6 → 51,9
TTM_PL_FLAG_CACHED |
TTM_PL_FLAG_NO_EVICT;
 
static uint32_t mob_placement_flags = VMW_PL_FLAG_MOB |
TTM_PL_FLAG_CACHED;
 
struct ttm_placement vmw_vram_placement = {
.fpfn = 0,
.lpfn = 0,
116,16 → 123,26
.busy_placement = &sys_placement_flags
};
 
struct ttm_placement vmw_sys_ne_placement = {
.fpfn = 0,
.lpfn = 0,
.num_placement = 1,
.placement = &sys_ne_placement_flags,
.num_busy_placement = 1,
.busy_placement = &sys_ne_placement_flags
};
 
static uint32_t evictable_placement_flags[] = {
TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED,
TTM_PL_FLAG_VRAM | TTM_PL_FLAG_CACHED,
VMW_PL_FLAG_GMR | TTM_PL_FLAG_CACHED
VMW_PL_FLAG_GMR | TTM_PL_FLAG_CACHED,
VMW_PL_FLAG_MOB | TTM_PL_FLAG_CACHED
};
 
struct ttm_placement vmw_evictable_placement = {
.fpfn = 0,
.lpfn = 0,
.num_placement = 3,
.num_placement = 4,
.placement = evictable_placement_flags,
.num_busy_placement = 1,
.busy_placement = &sys_placement_flags
140,38 → 157,485
.busy_placement = gmr_vram_placement_flags
};
 
struct ttm_placement vmw_mob_placement = {
.fpfn = 0,
.lpfn = 0,
.num_placement = 1,
.num_busy_placement = 1,
.placement = &mob_placement_flags,
.busy_placement = &mob_placement_flags
};
 
struct vmw_ttm_tt {
struct ttm_tt ttm;
struct ttm_dma_tt dma_ttm;
struct vmw_private *dev_priv;
int gmr_id;
struct vmw_mob *mob;
int mem_type;
struct sg_table sgt;
struct vmw_sg_table vsgt;
uint64_t sg_alloc_size;
bool mapped;
};
 
const size_t vmw_tt_size = sizeof(struct vmw_ttm_tt);
 
/**
* Helper functions to advance a struct vmw_piter iterator.
*
* @viter: Pointer to the iterator.
*
* These functions return false if past the end of the list,
* true otherwise. Functions are selected depending on the current
* DMA mapping mode.
*/
static bool __vmw_piter_non_sg_next(struct vmw_piter *viter)
{
return ++(viter->i) < viter->num_pages;
}
 
static bool __vmw_piter_sg_next(struct vmw_piter *viter)
{
return __sg_page_iter_next(&viter->iter);
}
 
 
/**
* Helper functions to return a pointer to the current page.
*
* @viter: Pointer to the iterator
*
* These functions return a pointer to the page currently
* pointed to by @viter. Functions are selected depending on the
* current mapping mode.
*/
static struct page *__vmw_piter_non_sg_page(struct vmw_piter *viter)
{
return viter->pages[viter->i];
}
 
static struct page *__vmw_piter_sg_page(struct vmw_piter *viter)
{
return sg_page_iter_page(&viter->iter);
}
 
 
/**
* Helper functions to return the DMA address of the current page.
*
* @viter: Pointer to the iterator
*
* These functions return the DMA address of the page currently
* pointed to by @viter. Functions are selected depending on the
* current mapping mode.
*/
static dma_addr_t __vmw_piter_phys_addr(struct vmw_piter *viter)
{
return page_to_phys(viter->pages[viter->i]);
}
 
static dma_addr_t __vmw_piter_dma_addr(struct vmw_piter *viter)
{
return viter->addrs[viter->i];
}
 
static dma_addr_t __vmw_piter_sg_addr(struct vmw_piter *viter)
{
return sg_page_iter_dma_address(&viter->iter);
}
 
 
/**
* vmw_piter_start - Initialize a struct vmw_piter.
*
* @viter: Pointer to the iterator to initialize
* @vsgt: Pointer to a struct vmw_sg_table to initialize from
*
* Note that we're following the convention of __sg_page_iter_start, so that
* the iterator doesn't point to a valid page after initialization; it has
* to be advanced one step first.
*/
void vmw_piter_start(struct vmw_piter *viter, const struct vmw_sg_table *vsgt,
unsigned long p_offset)
{
viter->i = p_offset - 1;
viter->num_pages = vsgt->num_pages;
switch (vsgt->mode) {
case vmw_dma_phys:
viter->next = &__vmw_piter_non_sg_next;
viter->dma_address = &__vmw_piter_phys_addr;
viter->page = &__vmw_piter_non_sg_page;
viter->pages = vsgt->pages;
break;
case vmw_dma_alloc_coherent:
viter->next = &__vmw_piter_non_sg_next;
viter->dma_address = &__vmw_piter_dma_addr;
viter->page = &__vmw_piter_non_sg_page;
viter->addrs = vsgt->addrs;
viter->pages = vsgt->pages;
break;
case vmw_dma_map_populate:
case vmw_dma_map_bind:
viter->next = &__vmw_piter_sg_next;
viter->dma_address = &__vmw_piter_sg_addr;
viter->page = &__vmw_piter_sg_page;
__sg_page_iter_start(&viter->iter, vsgt->sgt->sgl,
vsgt->sgt->orig_nents, p_offset);
break;
default:
BUG();
}
}
 
/**
* vmw_ttm_unmap_from_dma - unmap device addresses previsouly mapped for
* TTM pages
*
* @vmw_tt: Pointer to a struct vmw_ttm_backend
*
* Used to free dma mappings previously mapped by vmw_ttm_map_for_dma.
*/
static void vmw_ttm_unmap_from_dma(struct vmw_ttm_tt *vmw_tt)
{
struct device *dev = vmw_tt->dev_priv->dev->dev;
 
dma_unmap_sg(dev, vmw_tt->sgt.sgl, vmw_tt->sgt.nents,
DMA_BIDIRECTIONAL);
vmw_tt->sgt.nents = vmw_tt->sgt.orig_nents;
}
 
/**
* vmw_ttm_map_for_dma - map TTM pages to get device addresses
*
* @vmw_tt: Pointer to a struct vmw_ttm_backend
*
* This function is used to get device addresses from the kernel DMA layer.
* However, it's violating the DMA API in that when this operation has been
* performed, it's illegal for the CPU to write to the pages without first
* unmapping the DMA mappings, or calling dma_sync_sg_for_cpu(). It is
* therefore only legal to call this function if we know that the function
* dma_sync_sg_for_cpu() is a NOP, and dma_sync_sg_for_device() is at most
* a CPU write buffer flush.
*/
static int vmw_ttm_map_for_dma(struct vmw_ttm_tt *vmw_tt)
{
struct device *dev = vmw_tt->dev_priv->dev->dev;
int ret;
 
ret = dma_map_sg(dev, vmw_tt->sgt.sgl, vmw_tt->sgt.orig_nents,
DMA_BIDIRECTIONAL);
if (unlikely(ret == 0))
return -ENOMEM;
 
vmw_tt->sgt.nents = ret;
 
return 0;
}
 
/**
* vmw_ttm_map_dma - Make sure TTM pages are visible to the device
*
* @vmw_tt: Pointer to a struct vmw_ttm_tt
*
* Select the correct function for and make sure the TTM pages are
* visible to the device. Allocate storage for the device mappings.
* If a mapping has already been performed, indicated by the storage
* pointer being non NULL, the function returns success.
*/
static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
{
struct vmw_private *dev_priv = vmw_tt->dev_priv;
struct ttm_mem_global *glob = vmw_mem_glob(dev_priv);
struct vmw_sg_table *vsgt = &vmw_tt->vsgt;
struct vmw_piter iter;
dma_addr_t old;
int ret = 0;
static size_t sgl_size;
static size_t sgt_size;
 
if (vmw_tt->mapped)
return 0;
 
vsgt->mode = dev_priv->map_mode;
vsgt->pages = vmw_tt->dma_ttm.ttm.pages;
vsgt->num_pages = vmw_tt->dma_ttm.ttm.num_pages;
vsgt->addrs = vmw_tt->dma_ttm.dma_address;
vsgt->sgt = &vmw_tt->sgt;
 
switch (dev_priv->map_mode) {
case vmw_dma_map_bind:
case vmw_dma_map_populate:
if (unlikely(!sgl_size)) {
sgl_size = ttm_round_pot(sizeof(struct scatterlist));
sgt_size = ttm_round_pot(sizeof(struct sg_table));
}
vmw_tt->sg_alloc_size = sgt_size + sgl_size * vsgt->num_pages;
ret = ttm_mem_global_alloc(glob, vmw_tt->sg_alloc_size, false,
true);
if (unlikely(ret != 0))
return ret;
 
ret = sg_alloc_table_from_pages(&vmw_tt->sgt, vsgt->pages,
vsgt->num_pages, 0,
(unsigned long)
vsgt->num_pages << PAGE_SHIFT,
GFP_KERNEL);
if (unlikely(ret != 0))
goto out_sg_alloc_fail;
 
if (vsgt->num_pages > vmw_tt->sgt.nents) {
uint64_t over_alloc =
sgl_size * (vsgt->num_pages -
vmw_tt->sgt.nents);
 
ttm_mem_global_free(glob, over_alloc);
vmw_tt->sg_alloc_size -= over_alloc;
}
 
ret = vmw_ttm_map_for_dma(vmw_tt);
if (unlikely(ret != 0))
goto out_map_fail;
 
break;
default:
break;
}
 
old = ~((dma_addr_t) 0);
vmw_tt->vsgt.num_regions = 0;
for (vmw_piter_start(&iter, vsgt, 0); vmw_piter_next(&iter);) {
dma_addr_t cur = vmw_piter_dma_addr(&iter);
 
if (cur != old + PAGE_SIZE)
vmw_tt->vsgt.num_regions++;
old = cur;
}
 
vmw_tt->mapped = true;
return 0;
 
out_map_fail:
sg_free_table(vmw_tt->vsgt.sgt);
vmw_tt->vsgt.sgt = NULL;
out_sg_alloc_fail:
ttm_mem_global_free(glob, vmw_tt->sg_alloc_size);
return ret;
}
 
/**
* vmw_ttm_unmap_dma - Tear down any TTM page device mappings
*
* @vmw_tt: Pointer to a struct vmw_ttm_tt
*
* Tear down any previously set up device DMA mappings and free
* any storage space allocated for them. If there are no mappings set up,
* this function is a NOP.
*/
static void vmw_ttm_unmap_dma(struct vmw_ttm_tt *vmw_tt)
{
struct vmw_private *dev_priv = vmw_tt->dev_priv;
 
if (!vmw_tt->vsgt.sgt)
return;
 
switch (dev_priv->map_mode) {
case vmw_dma_map_bind:
case vmw_dma_map_populate:
vmw_ttm_unmap_from_dma(vmw_tt);
sg_free_table(vmw_tt->vsgt.sgt);
vmw_tt->vsgt.sgt = NULL;
ttm_mem_global_free(vmw_mem_glob(dev_priv),
vmw_tt->sg_alloc_size);
break;
default:
break;
}
vmw_tt->mapped = false;
}
 
 
/**
* vmw_bo_map_dma - Make sure buffer object pages are visible to the device
*
* @bo: Pointer to a struct ttm_buffer_object
*
* Wrapper around vmw_ttm_map_dma, that takes a TTM buffer object pointer
* instead of a pointer to a struct vmw_ttm_backend as argument.
* Note that the buffer object must be either pinned or reserved before
* calling this function.
*/
int vmw_bo_map_dma(struct ttm_buffer_object *bo)
{
struct vmw_ttm_tt *vmw_tt =
container_of(bo->ttm, struct vmw_ttm_tt, dma_ttm.ttm);
 
return vmw_ttm_map_dma(vmw_tt);
}
 
 
/**
* vmw_bo_unmap_dma - Make sure buffer object pages are visible to the device
*
* @bo: Pointer to a struct ttm_buffer_object
*
* Wrapper around vmw_ttm_unmap_dma, that takes a TTM buffer object pointer
* instead of a pointer to a struct vmw_ttm_backend as argument.
*/
void vmw_bo_unmap_dma(struct ttm_buffer_object *bo)
{
struct vmw_ttm_tt *vmw_tt =
container_of(bo->ttm, struct vmw_ttm_tt, dma_ttm.ttm);
 
vmw_ttm_unmap_dma(vmw_tt);
}
 
 
/**
* vmw_bo_sg_table - Return a struct vmw_sg_table object for a
* TTM buffer object
*
* @bo: Pointer to a struct ttm_buffer_object
*
* Returns a pointer to a struct vmw_sg_table object. The object should
* not be freed after use.
* Note that for the device addresses to be valid, the buffer object must
* either be reserved or pinned.
*/
const struct vmw_sg_table *vmw_bo_sg_table(struct ttm_buffer_object *bo)
{
struct vmw_ttm_tt *vmw_tt =
container_of(bo->ttm, struct vmw_ttm_tt, dma_ttm.ttm);
 
return &vmw_tt->vsgt;
}
 
 
static int vmw_ttm_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
{
struct vmw_ttm_tt *vmw_be = container_of(ttm, struct vmw_ttm_tt, ttm);
struct vmw_ttm_tt *vmw_be =
container_of(ttm, struct vmw_ttm_tt, dma_ttm.ttm);
int ret;
 
ret = vmw_ttm_map_dma(vmw_be);
if (unlikely(ret != 0))
return ret;
 
vmw_be->gmr_id = bo_mem->start;
vmw_be->mem_type = bo_mem->mem_type;
 
return vmw_gmr_bind(vmw_be->dev_priv, ttm->pages,
switch (bo_mem->mem_type) {
case VMW_PL_GMR:
return vmw_gmr_bind(vmw_be->dev_priv, &vmw_be->vsgt,
ttm->num_pages, vmw_be->gmr_id);
case VMW_PL_MOB:
if (unlikely(vmw_be->mob == NULL)) {
vmw_be->mob =
vmw_mob_create(ttm->num_pages);
if (unlikely(vmw_be->mob == NULL))
return -ENOMEM;
}
 
return vmw_mob_bind(vmw_be->dev_priv, vmw_be->mob,
&vmw_be->vsgt, ttm->num_pages,
vmw_be->gmr_id);
default:
BUG();
}
return 0;
}
 
static int vmw_ttm_unbind(struct ttm_tt *ttm)
{
struct vmw_ttm_tt *vmw_be = container_of(ttm, struct vmw_ttm_tt, ttm);
struct vmw_ttm_tt *vmw_be =
container_of(ttm, struct vmw_ttm_tt, dma_ttm.ttm);
 
switch (vmw_be->mem_type) {
case VMW_PL_GMR:
vmw_gmr_unbind(vmw_be->dev_priv, vmw_be->gmr_id);
break;
case VMW_PL_MOB:
vmw_mob_unbind(vmw_be->dev_priv, vmw_be->mob);
break;
default:
BUG();
}
 
if (vmw_be->dev_priv->map_mode == vmw_dma_map_bind)
vmw_ttm_unmap_dma(vmw_be);
 
return 0;
}
 
 
static void vmw_ttm_destroy(struct ttm_tt *ttm)
{
struct vmw_ttm_tt *vmw_be = container_of(ttm, struct vmw_ttm_tt, ttm);
struct vmw_ttm_tt *vmw_be =
container_of(ttm, struct vmw_ttm_tt, dma_ttm.ttm);
 
vmw_ttm_unmap_dma(vmw_be);
if (vmw_be->dev_priv->map_mode == vmw_dma_alloc_coherent)
ttm_dma_tt_fini(&vmw_be->dma_ttm);
else
ttm_tt_fini(ttm);
 
if (vmw_be->mob)
vmw_mob_destroy(vmw_be->mob);
 
kfree(vmw_be);
}
 
 
static int vmw_ttm_populate(struct ttm_tt *ttm)
{
struct vmw_ttm_tt *vmw_tt =
container_of(ttm, struct vmw_ttm_tt, dma_ttm.ttm);
struct vmw_private *dev_priv = vmw_tt->dev_priv;
struct ttm_mem_global *glob = vmw_mem_glob(dev_priv);
int ret;
 
if (ttm->state != tt_unpopulated)
return 0;
 
if (dev_priv->map_mode == vmw_dma_alloc_coherent) {
size_t size =
ttm_round_pot(ttm->num_pages * sizeof(dma_addr_t));
ret = ttm_mem_global_alloc(glob, size, false, true);
if (unlikely(ret != 0))
return ret;
 
ret = ttm_dma_populate(&vmw_tt->dma_ttm, dev_priv->dev->dev);
if (unlikely(ret != 0))
ttm_mem_global_free(glob, size);
} else
ret = ttm_pool_populate(ttm);
 
return ret;
}
 
static void vmw_ttm_unpopulate(struct ttm_tt *ttm)
{
struct vmw_ttm_tt *vmw_tt = container_of(ttm, struct vmw_ttm_tt,
dma_ttm.ttm);
struct vmw_private *dev_priv = vmw_tt->dev_priv;
struct ttm_mem_global *glob = vmw_mem_glob(dev_priv);
 
 
if (vmw_tt->mob) {
vmw_mob_destroy(vmw_tt->mob);
vmw_tt->mob = NULL;
}
 
vmw_ttm_unmap_dma(vmw_tt);
if (dev_priv->map_mode == vmw_dma_alloc_coherent) {
size_t size =
ttm_round_pot(ttm->num_pages * sizeof(dma_addr_t));
 
ttm_dma_unpopulate(&vmw_tt->dma_ttm, dev_priv->dev->dev);
ttm_mem_global_free(glob, size);
} else
ttm_pool_unpopulate(ttm);
}
 
static struct ttm_backend_func vmw_ttm_func = {
.bind = vmw_ttm_bind,
.unbind = vmw_ttm_unbind,
178,33 → 642,42
.destroy = vmw_ttm_destroy,
};
 
struct ttm_tt *vmw_ttm_tt_create(struct ttm_bo_device *bdev,
static struct ttm_tt *vmw_ttm_tt_create(struct ttm_bo_device *bdev,
unsigned long size, uint32_t page_flags,
struct page *dummy_read_page)
{
struct vmw_ttm_tt *vmw_be;
int ret;
 
vmw_be = kmalloc(sizeof(*vmw_be), GFP_KERNEL);
vmw_be = kzalloc(sizeof(*vmw_be), GFP_KERNEL);
if (!vmw_be)
return NULL;
 
vmw_be->ttm.func = &vmw_ttm_func;
vmw_be->dma_ttm.ttm.func = &vmw_ttm_func;
vmw_be->dev_priv = container_of(bdev, struct vmw_private, bdev);
vmw_be->mob = NULL;
 
if (ttm_tt_init(&vmw_be->ttm, bdev, size, page_flags, dummy_read_page)) {
if (vmw_be->dev_priv->map_mode == vmw_dma_alloc_coherent)
ret = ttm_dma_tt_init(&vmw_be->dma_ttm, bdev, size, page_flags,
dummy_read_page);
else
ret = ttm_tt_init(&vmw_be->dma_ttm.ttm, bdev, size, page_flags,
dummy_read_page);
if (unlikely(ret != 0))
goto out_no_init;
 
return &vmw_be->dma_ttm.ttm;
out_no_init:
kfree(vmw_be);
return NULL;
}
 
return &vmw_be->ttm;
}
 
int vmw_invalidate_caches(struct ttm_bo_device *bdev, uint32_t flags)
static int vmw_invalidate_caches(struct ttm_bo_device *bdev, uint32_t flags)
{
return 0;
}
 
int vmw_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
static int vmw_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
struct ttm_mem_type_manager *man)
{
switch (type) {
224,6 → 697,7
man->default_caching = TTM_PL_FLAG_CACHED;
break;
case VMW_PL_GMR:
case VMW_PL_MOB:
/*
* "Guest Memory Regions" is an aperture like feature with
* one slot per bo. There is an upper limit of the number of
242,7 → 716,7
return 0;
}
 
void vmw_evict_flags(struct ttm_buffer_object *bo,
static void vmw_evict_flags(struct ttm_buffer_object *bo,
struct ttm_placement *placement)
{
*placement = vmw_sys_placement;
271,6 → 745,7
switch (mem->mem_type) {
case TTM_PL_SYSTEM:
case VMW_PL_GMR:
case VMW_PL_MOB:
return 0;
case TTM_PL_VRAM:
mem->bus.offset = mem->start << PAGE_SHIFT;
330,10 → 805,42
VMW_FENCE_WAIT_TIMEOUT);
}
 
/**
* vmw_move_notify - TTM move_notify_callback
*
* @bo: The TTM buffer object about to move.
* @mem: The truct ttm_mem_reg indicating to what memory
* region the move is taking place.
*
* Calls move_notify for all subsystems needing it.
* (currently only resources).
*/
static void vmw_move_notify(struct ttm_buffer_object *bo,
struct ttm_mem_reg *mem)
{
vmw_resource_move_notify(bo, mem);
}
 
 
/**
* vmw_swap_notify - TTM move_notify_callback
*
* @bo: The TTM buffer object about to be swapped out.
*/
static void vmw_swap_notify(struct ttm_buffer_object *bo)
{
struct ttm_bo_device *bdev = bo->bdev;
 
// spin_lock(&bdev->fence_lock);
// ttm_bo_wait(bo, false, false, false);
// spin_unlock(&bdev->fence_lock);
}
 
 
struct ttm_bo_driver vmw_bo_driver = {
.ttm_tt_create = &vmw_ttm_tt_create,
.ttm_tt_populate = &ttm_pool_populate,
.ttm_tt_unpopulate = &ttm_pool_unpopulate,
.ttm_tt_populate = &vmw_ttm_populate,
.ttm_tt_unpopulate = &vmw_ttm_unpopulate,
.invalidate_caches = vmw_invalidate_caches,
.init_mem_type = vmw_init_mem_type,
.evict_flags = vmw_evict_flags,
344,9 → 851,243
.sync_obj_flush = vmw_sync_obj_flush,
.sync_obj_unref = vmw_sync_obj_unref,
.sync_obj_ref = vmw_sync_obj_ref,
.move_notify = NULL,
.swap_notify = NULL,
.move_notify = vmw_move_notify,
.swap_notify = vmw_swap_notify,
.fault_reserve_notify = &vmw_ttm_fault_reserve_notify,
.io_mem_reserve = &vmw_ttm_io_mem_reserve,
.io_mem_free = &vmw_ttm_io_mem_free,
};
 
 
struct scatterlist *sg_next(struct scatterlist *sg)
{
if (sg_is_last(sg))
return NULL;
 
sg++;
if (unlikely(sg_is_chain(sg)))
sg = sg_chain_ptr(sg);
 
return sg;
}
 
 
void __sg_free_table(struct sg_table *table, unsigned int max_ents,
sg_free_fn *free_fn)
{
struct scatterlist *sgl, *next;
 
if (unlikely(!table->sgl))
return;
 
sgl = table->sgl;
while (table->orig_nents) {
unsigned int alloc_size = table->orig_nents;
unsigned int sg_size;
 
/*
* If we have more than max_ents segments left,
* then assign 'next' to the sg table after the current one.
* sg_size is then one less than alloc size, since the last
* element is the chain pointer.
*/
if (alloc_size > max_ents) {
next = sg_chain_ptr(&sgl[max_ents - 1]);
alloc_size = max_ents;
sg_size = alloc_size - 1;
} else {
sg_size = alloc_size;
next = NULL;
}
 
table->orig_nents -= sg_size;
kfree(sgl);
sgl = next;
}
 
table->sgl = NULL;
}
 
void sg_free_table(struct sg_table *table)
{
__sg_free_table(table, SG_MAX_SINGLE_ALLOC, NULL);
}
 
int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
{
struct scatterlist *sg, *prv;
unsigned int left;
unsigned int max_ents = SG_MAX_SINGLE_ALLOC;
 
#ifndef ARCH_HAS_SG_CHAIN
BUG_ON(nents > max_ents);
#endif
 
memset(table, 0, sizeof(*table));
 
left = nents;
prv = NULL;
do {
unsigned int sg_size, alloc_size = left;
 
if (alloc_size > max_ents) {
alloc_size = max_ents;
sg_size = alloc_size - 1;
} else
sg_size = alloc_size;
 
left -= sg_size;
 
sg = kmalloc(alloc_size * sizeof(struct scatterlist), gfp_mask);
if (unlikely(!sg)) {
/*
* Adjust entry count to reflect that the last
* entry of the previous table won't be used for
* linkage. Without this, sg_kfree() may get
* confused.
*/
if (prv)
table->nents = ++table->orig_nents;
 
goto err;
}
 
sg_init_table(sg, alloc_size);
table->nents = table->orig_nents += sg_size;
 
/*
* If this is the first mapping, assign the sg table header.
* If this is not the first mapping, chain previous part.
*/
if (prv)
sg_chain(prv, max_ents, sg);
else
table->sgl = sg;
 
/*
* If no more entries after this one, mark the end
*/
if (!left)
sg_mark_end(&sg[sg_size - 1]);
 
prv = sg;
} while (left);
 
return 0;
 
err:
__sg_free_table(table, SG_MAX_SINGLE_ALLOC, NULL);
 
return -ENOMEM;
}
 
 
void sg_init_table(struct scatterlist *sgl, unsigned int nents)
{
memset(sgl, 0, sizeof(*sgl) * nents);
#ifdef CONFIG_DEBUG_SG
{
unsigned int i;
for (i = 0; i < nents; i++)
sgl[i].sg_magic = SG_MAGIC;
}
#endif
sg_mark_end(&sgl[nents - 1]);
}
 
 
void __sg_page_iter_start(struct sg_page_iter *piter,
struct scatterlist *sglist, unsigned int nents,
unsigned long pgoffset)
{
piter->__pg_advance = 0;
piter->__nents = nents;
 
piter->sg = sglist;
piter->sg_pgoffset = pgoffset;
}
 
static int sg_page_count(struct scatterlist *sg)
{
return PAGE_ALIGN(sg->offset + sg->length) >> PAGE_SHIFT;
}
 
bool __sg_page_iter_next(struct sg_page_iter *piter)
{
if (!piter->__nents || !piter->sg)
return false;
 
piter->sg_pgoffset += piter->__pg_advance;
piter->__pg_advance = 1;
 
while (piter->sg_pgoffset >= sg_page_count(piter->sg)) {
piter->sg_pgoffset -= sg_page_count(piter->sg);
piter->sg = sg_next(piter->sg);
if (!--piter->__nents || !piter->sg)
return false;
}
 
return true;
}
EXPORT_SYMBOL(__sg_page_iter_next);
 
 
int sg_alloc_table_from_pages(struct sg_table *sgt,
struct page **pages, unsigned int n_pages,
unsigned long offset, unsigned long size,
gfp_t gfp_mask)
{
unsigned int chunks;
unsigned int i;
unsigned int cur_page;
int ret;
struct scatterlist *s;
 
/* compute number of contiguous chunks */
chunks = 1;
for (i = 1; i < n_pages; ++i)
if (page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1)
++chunks;
 
ret = sg_alloc_table(sgt, chunks, gfp_mask);
if (unlikely(ret))
return ret;
 
/* merging chunks and putting them into the scatterlist */
cur_page = 0;
for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
unsigned long chunk_size;
unsigned int j;
 
/* look for the end of the current chunk */
for (j = cur_page + 1; j < n_pages; ++j)
if (page_to_pfn(pages[j]) !=
page_to_pfn(pages[j - 1]) + 1)
break;
 
chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset;
sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
size -= chunk_size;
offset = 0;
cur_page = j;
}
 
return 0;
}
 
int dma_map_sg(struct device *dev, struct scatterlist *sglist,
int nelems, int dir)
{
struct scatterlist *s;
int i;
 
for_each_sg(sglist, s, nelems, i) {
s->dma_address = (dma_addr_t)sg_phys(s);
#ifdef CONFIG_NEED_SG_DMA_LENGTH
s->dma_length = s->length;
#endif
}
 
return nelems;
}