From d92d985177c495aab53c7167f310a7efb1853918 Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thellstrom@vmware.com>
Date: Thu, 24 Oct 2013 01:49:26 -0700
Subject: 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>
---
drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c | 379 +++++++++++++++++++++++++++++++--
1 file changed, 362 insertions(+), 17 deletions(-)
(limited to 'drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c')
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
index 96dc84dc34d..7776e6f0aef 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
@@ -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);
-
- ttm_tt_fini(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);
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;
- }
-
- return &vmw_be->ttm;
+ 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;
}
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,
--
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