drm/vmwgfx: Use the linux DMA api to get valid device addresses of pages

The code handles three different cases:
1) physical page addresses. The ttm page array is used.
2) DMA subsystem addresses. A scatter-gather list is used.
3) Coherent pages. The ttm dma pool is used, together with the dma_ttm
array os dma_addr_t

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
This commit is contained in:
Thomas Hellstrom
2013-10-24 01:49:26 -07:00
parent 7aeb7448d8
commit d92d985177
4 changed files with 618 additions and 92 deletions

View File

@@ -141,37 +141,374 @@ struct ttm_placement vmw_srf_placement = {
};
struct vmw_ttm_tt {
struct ttm_tt ttm;
struct ttm_dma_tt dma_ttm;
struct vmw_private *dev_priv;
int gmr_id;
struct sg_table sgt;
struct vmw_sg_table vsgt;
uint64_t sg_alloc_size;
bool mapped;
};
/**
* 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;
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;
}
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;
return vmw_gmr_bind(vmw_be->dev_priv, ttm->pages,
return vmw_gmr_bind(vmw_be->dev_priv, &vmw_be->vsgt,
ttm->num_pages, vmw_be->gmr_id);
}
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);
vmw_gmr_unbind(vmw_be->dev_priv, vmw_be->gmr_id);
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);
ttm_tt_fini(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);
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);
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,
@@ -183,20 +520,28 @@ struct ttm_tt *vmw_ttm_tt_create(struct ttm_bo_device *bdev,
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);
if (ttm_tt_init(&vmw_be->ttm, bdev, size, page_flags, dummy_read_page)) {
kfree(vmw_be);
return NULL;
}
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->ttm;
return &vmw_be->dma_ttm.ttm;
out_no_init:
kfree(vmw_be);
return NULL;
}
int vmw_invalidate_caches(struct ttm_bo_device *bdev, uint32_t flags)
@@ -332,8 +677,8 @@ static int vmw_sync_obj_wait(void *sync_obj, bool lazy, bool interruptible)
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,