drm/vmwgfx: Use the linux DMA api to get valid device addresses of pages
authorThomas Hellstrom <thellstrom@vmware.com>
Thu, 24 Oct 2013 08:49:26 +0000 (01:49 -0700)
committerThomas Hellstrom <thellstrom@vmware.com>
Wed, 6 Nov 2013 11:57:16 +0000 (03:57 -0800)
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
drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
drivers/gpu/drm/vmwgfx/vmwgfx_gmr.c

index 96dc84dc34d05122c877322b3415eff84d64af39..7776e6f0aef650d475e39640b3d781b42f8d7036 100644 (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);
-
-       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,
index 1a90f0a2f7e5aa7b994558b18a3cffd2d1254ee8..0b5c7818ebfb305dc2086d9960db88f78da67f99 100644 (file)
@@ -32,6 +32,7 @@
 #include <drm/ttm/ttm_bo_driver.h>
 #include <drm/ttm/ttm_object.h>
 #include <drm/ttm/ttm_module.h>
+#include <linux/dma_remapping.h>
 
 #define VMWGFX_DRIVER_NAME "vmwgfx"
 #define VMWGFX_DRIVER_DESC "Linux drm driver for VMware graphics devices"
@@ -185,6 +186,9 @@ static struct pci_device_id vmw_pci_id_list[] = {
 MODULE_DEVICE_TABLE(pci, vmw_pci_id_list);
 
 static int enable_fbdev = IS_ENABLED(CONFIG_DRM_VMWGFX_FBCON);
+static int vmw_force_iommu;
+static int vmw_restrict_iommu;
+static int vmw_force_coherent;
 
 static int vmw_probe(struct pci_dev *, const struct pci_device_id *);
 static void vmw_master_init(struct vmw_master *);
@@ -193,6 +197,13 @@ static int vmwgfx_pm_notifier(struct notifier_block *nb, unsigned long val,
 
 MODULE_PARM_DESC(enable_fbdev, "Enable vmwgfx fbdev");
 module_param_named(enable_fbdev, enable_fbdev, int, 0600);
+MODULE_PARM_DESC(force_dma_api, "Force using the DMA API for TTM pages");
+module_param_named(force_dma_api, vmw_force_iommu, int, 0600);
+MODULE_PARM_DESC(restrict_iommu, "Try to limit IOMMU usage for TTM pages");
+module_param_named(restrict_iommu, vmw_restrict_iommu, int, 0600);
+MODULE_PARM_DESC(force_coherent, "Force coherent TTM pages");
+module_param_named(force_coherent, vmw_force_coherent, int, 0600);
+
 
 static void vmw_print_capabilities(uint32_t capabilities)
 {
@@ -427,12 +438,78 @@ static void vmw_get_initial_size(struct vmw_private *dev_priv)
        dev_priv->initial_height = height;
 }
 
+/**
+ * vmw_dma_select_mode - Determine how DMA mappings should be set up for this
+ * system.
+ *
+ * @dev_priv: Pointer to a struct vmw_private
+ *
+ * This functions tries to determine the IOMMU setup and what actions
+ * need to be taken by the driver to make system pages visible to the
+ * device.
+ * If this function decides that DMA is not possible, it returns -EINVAL.
+ * The driver may then try to disable features of the device that require
+ * DMA.
+ */
+static int vmw_dma_select_mode(struct vmw_private *dev_priv)
+{
+       const struct dma_map_ops *dma_ops = get_dma_ops(dev_priv->dev->dev);
+       static const char *names[vmw_dma_map_max] = {
+               [vmw_dma_phys] = "Using physical TTM page addresses.",
+               [vmw_dma_alloc_coherent] = "Using coherent TTM pages.",
+               [vmw_dma_map_populate] = "Keeping DMA mappings.",
+               [vmw_dma_map_bind] = "Giving up DMA mappings early."};
+
+#ifdef CONFIG_INTEL_IOMMU
+       if (intel_iommu_enabled) {
+               dev_priv->map_mode = vmw_dma_map_populate;
+               goto out_fixup;
+       }
+#endif
+
+       if (!(vmw_force_iommu || vmw_force_coherent)) {
+               dev_priv->map_mode = vmw_dma_phys;
+               DRM_INFO("DMA map mode: %s\n", names[dev_priv->map_mode]);
+               return 0;
+       }
+
+       dev_priv->map_mode = vmw_dma_map_populate;
+
+       if (dma_ops->sync_single_for_cpu)
+               dev_priv->map_mode = vmw_dma_alloc_coherent;
+#ifdef CONFIG_SWIOTLB
+       if (swiotlb_nr_tbl() == 0)
+               dev_priv->map_mode = vmw_dma_map_populate;
+#endif
+
+out_fixup:
+       if (dev_priv->map_mode == vmw_dma_map_populate &&
+           vmw_restrict_iommu)
+               dev_priv->map_mode = vmw_dma_map_bind;
+
+       if (vmw_force_coherent)
+               dev_priv->map_mode = vmw_dma_alloc_coherent;
+
+#if !defined(CONFIG_SWIOTLB) && !defined(CONFIG_INTEL_IOMMU)
+       /*
+        * No coherent page pool
+        */
+       if (dev_priv->map_mode == vmw_dma_alloc_coherent)
+               return -EINVAL;
+#endif
+
+       DRM_INFO("DMA map mode: %s\n", names[dev_priv->map_mode]);
+
+       return 0;
+}
+
 static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 {
        struct vmw_private *dev_priv;
        int ret;
        uint32_t svga_id;
        enum vmw_res_type i;
+       bool refuse_dma = false;
 
        dev_priv = kzalloc(sizeof(*dev_priv), GFP_KERNEL);
        if (unlikely(dev_priv == NULL)) {
@@ -481,6 +558,11 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
        }
 
        dev_priv->capabilities = vmw_read(dev_priv, SVGA_REG_CAPABILITIES);
+       ret = vmw_dma_select_mode(dev_priv);
+       if (unlikely(ret != 0)) {
+               DRM_INFO("Restricting capabilities due to IOMMU setup.\n");
+               refuse_dma = true;
+       }
 
        dev_priv->vram_size = vmw_read(dev_priv, SVGA_REG_VRAM_SIZE);
        dev_priv->mmio_size = vmw_read(dev_priv, SVGA_REG_MEM_SIZE);
@@ -558,8 +640,9 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
        }
 
        dev_priv->has_gmr = true;
-       if (ttm_bo_init_mm(&dev_priv->bdev, VMW_PL_GMR,
-                          dev_priv->max_gmr_ids) != 0) {
+       if (((dev_priv->capabilities & (SVGA_CAP_GMR | SVGA_CAP_GMR2)) == 0) ||
+           refuse_dma || ttm_bo_init_mm(&dev_priv->bdev, VMW_PL_GMR,
+                                        dev_priv->max_gmr_ids) != 0) {
                DRM_INFO("No GMR memory available. "
                         "Graphics memory resources are very limited.\n");
                dev_priv->has_gmr = false;
index 150ec64af617e4974250a6deb36a5c6234766341..e401d5dbcb964eb59c13fe2c5923f72370155eef 100644 (file)
@@ -177,6 +177,58 @@ struct vmw_res_cache_entry {
        struct vmw_resource_val_node *node;
 };
 
+/**
+ * enum vmw_dma_map_mode - indicate how to perform TTM page dma mappings.
+ */
+enum vmw_dma_map_mode {
+       vmw_dma_phys,           /* Use physical page addresses */
+       vmw_dma_alloc_coherent, /* Use TTM coherent pages */
+       vmw_dma_map_populate,   /* Unmap from DMA just after unpopulate */
+       vmw_dma_map_bind,       /* Unmap from DMA just before unbind */
+       vmw_dma_map_max
+};
+
+/**
+ * struct vmw_sg_table - Scatter/gather table for binding, with additional
+ * device-specific information.
+ *
+ * @sgt: Pointer to a struct sg_table with binding information
+ * @num_regions: Number of regions with device-address contigous pages
+ */
+struct vmw_sg_table {
+       enum vmw_dma_map_mode mode;
+       struct page **pages;
+       const dma_addr_t *addrs;
+       struct sg_table *sgt;
+       unsigned long num_regions;
+       unsigned long num_pages;
+};
+
+/**
+ * struct vmw_piter - Page iterator that iterates over a list of pages
+ * and DMA addresses that could be either a scatter-gather list or
+ * arrays
+ *
+ * @pages: Array of page pointers to the pages.
+ * @addrs: DMA addresses to the pages if coherent pages are used.
+ * @iter: Scatter-gather page iterator. Current position in SG list.
+ * @i: Current position in arrays.
+ * @num_pages: Number of pages total.
+ * @next: Function to advance the iterator. Returns false if past the list
+ * of pages, true otherwise.
+ * @dma_address: Function to return the DMA address of the current page.
+ */
+struct vmw_piter {
+       struct page **pages;
+       const dma_addr_t *addrs;
+       struct sg_page_iter iter;
+       unsigned long i;
+       unsigned long num_pages;
+       bool (*next)(struct vmw_piter *);
+       dma_addr_t (*dma_address)(struct vmw_piter *);
+       struct page *(*page)(struct vmw_piter *);
+};
+
 struct vmw_sw_context{
        struct drm_open_hash res_ht;
        bool res_ht_initialized;
@@ -358,6 +410,11 @@ struct vmw_private {
 
        struct list_head res_lru[vmw_res_max];
        uint32_t used_memory_size;
+
+       /*
+        * DMA mapping stuff.
+        */
+       enum vmw_dma_map_mode map_mode;
 };
 
 static inline struct vmw_surface *vmw_res_to_srf(struct vmw_resource *res)
@@ -405,7 +462,7 @@ void vmw_3d_resource_dec(struct vmw_private *dev_priv, bool hide_svga);
  */
 
 extern int vmw_gmr_bind(struct vmw_private *dev_priv,
-                       struct page *pages[],
+                       const struct vmw_sg_table *vsgt,
                        unsigned long num_pages,
                        int gmr_id);
 extern void vmw_gmr_unbind(struct vmw_private *dev_priv, int gmr_id);
@@ -568,6 +625,45 @@ extern struct ttm_placement vmw_evictable_placement;
 extern struct ttm_placement vmw_srf_placement;
 extern struct ttm_bo_driver vmw_bo_driver;
 extern int vmw_dma_quiescent(struct drm_device *dev);
+extern void vmw_piter_start(struct vmw_piter *viter,
+                           const struct vmw_sg_table *vsgt,
+                           unsigned long p_offs);
+
+/**
+ * vmw_piter_next - Advance the iterator one page.
+ *
+ * @viter: Pointer to the iterator to advance.
+ *
+ * Returns false if past the list of pages, true otherwise.
+ */
+static inline bool vmw_piter_next(struct vmw_piter *viter)
+{
+       return viter->next(viter);
+}
+
+/**
+ * vmw_piter_dma_addr - Return the DMA address of the current page.
+ *
+ * @viter: Pointer to the iterator
+ *
+ * Returns the DMA address of the page pointed to by @viter.
+ */
+static inline dma_addr_t vmw_piter_dma_addr(struct vmw_piter *viter)
+{
+       return viter->dma_address(viter);
+}
+
+/**
+ * vmw_piter_page - Return a pointer to the current page.
+ *
+ * @viter: Pointer to the iterator
+ *
+ * Returns the DMA address of the page pointed to by @viter.
+ */
+static inline struct page *vmw_piter_page(struct vmw_piter *viter)
+{
+       return viter->page(viter);
+}
 
 /**
  * Command submission - vmwgfx_execbuf.c
index 1a0bf07fe54b8c41dd16ab274c48ca6cc6043d32..6d0952366f91015f0747faf58316cd571a3058a8 100644 (file)
 #define VMW_PPN_SIZE (sizeof(unsigned long))
 /* A future safe maximum remap size. */
 #define VMW_PPN_PER_REMAP ((31 * 1024) / VMW_PPN_SIZE)
+#define DMA_ADDR_INVALID ((dma_addr_t) 0)
+#define DMA_PAGE_INVALID 0UL
 
 static int vmw_gmr2_bind(struct vmw_private *dev_priv,
-                        struct page *pages[],
+                        struct vmw_piter *iter,
                         unsigned long num_pages,
                         int gmr_id)
 {
@@ -81,11 +83,13 @@ static int vmw_gmr2_bind(struct vmw_private *dev_priv,
 
                for (i = 0; i < nr; ++i) {
                        if (VMW_PPN_SIZE <= 4)
-                               *cmd = page_to_pfn(*pages++);
+                               *cmd = vmw_piter_dma_addr(iter) >> PAGE_SHIFT;
                        else
-                               *((uint64_t *)cmd) = page_to_pfn(*pages++);
+                               *((uint64_t *)cmd) = vmw_piter_dma_addr(iter) >>
+                                       PAGE_SHIFT;
 
                        cmd += VMW_PPN_SIZE / sizeof(*cmd);
+                       vmw_piter_next(iter);
                }
 
                num_pages -= nr;
@@ -120,22 +124,54 @@ static void vmw_gmr2_unbind(struct vmw_private *dev_priv,
        vmw_fifo_commit(dev_priv, define_size);
 }
 
+
+static void vmw_gmr_free_descriptors(struct device *dev, dma_addr_t desc_dma,
+                                    struct list_head *desc_pages)
+{
+       struct page *page, *next;
+       struct svga_guest_mem_descriptor *page_virtual;
+       unsigned int desc_per_page = PAGE_SIZE /
+               sizeof(struct svga_guest_mem_descriptor) - 1;
+
+       if (list_empty(desc_pages))
+               return;
+
+       list_for_each_entry_safe(page, next, desc_pages, lru) {
+               list_del_init(&page->lru);
+
+               if (likely(desc_dma != DMA_ADDR_INVALID)) {
+                       dma_unmap_page(dev, desc_dma, PAGE_SIZE,
+                                      DMA_TO_DEVICE);
+               }
+
+               page_virtual = kmap_atomic(page);
+               desc_dma = page_virtual[desc_per_page].ppn << PAGE_SHIFT;
+               kunmap_atomic(page_virtual);
+
+               __free_page(page);
+       }
+}
+
 /**
  * FIXME: Adjust to the ttm lowmem / highmem storage to minimize
  * the number of used descriptors.
+ *
  */
 
-static int vmw_gmr_build_descriptors(struct list_head *desc_pages,
-                                    struct page *pages[],
-                                    unsigned long num_pages)
+static int vmw_gmr_build_descriptors(struct device *dev,
+                                    struct list_head *desc_pages,
+                                    struct vmw_piter *iter,
+                                    unsigned long num_pages,
+                                    dma_addr_t *first_dma)
 {
-       struct page *page, *next;
+       struct page *page;
        struct svga_guest_mem_descriptor *page_virtual = NULL;
        struct svga_guest_mem_descriptor *desc_virtual = NULL;
        unsigned int desc_per_page;
        unsigned long prev_pfn;
        unsigned long pfn;
        int ret;
+       dma_addr_t desc_dma;
 
        desc_per_page = PAGE_SIZE /
            sizeof(struct svga_guest_mem_descriptor) - 1;
@@ -148,23 +184,12 @@ static int vmw_gmr_build_descriptors(struct list_head *desc_pages,
                }
 
                list_add_tail(&page->lru, desc_pages);
-
-               /*
-                * Point previous page terminating descriptor to this
-                * page before unmapping it.
-                */
-
-               if (likely(page_virtual != NULL)) {
-                       desc_virtual->ppn = page_to_pfn(page);
-                       kunmap_atomic(page_virtual);
-               }
-
                page_virtual = kmap_atomic(page);
                desc_virtual = page_virtual - 1;
                prev_pfn = ~(0UL);
 
                while (likely(num_pages != 0)) {
-                       pfn = page_to_pfn(*pages);
+                       pfn = vmw_piter_dma_addr(iter) >> PAGE_SHIFT;
 
                        if (pfn != prev_pfn + 1) {
 
@@ -181,104 +206,81 @@ static int vmw_gmr_build_descriptors(struct list_head *desc_pages,
                        }
                        prev_pfn = pfn;
                        --num_pages;
-                       ++pages;
+                       vmw_piter_next(iter);
                }
 
-               (++desc_virtual)->ppn = cpu_to_le32(0);
+               (++desc_virtual)->ppn = DMA_PAGE_INVALID;
                desc_virtual->num_pages = cpu_to_le32(0);
+               kunmap_atomic(page_virtual);
        }
 
-       if (likely(page_virtual != NULL))
+       desc_dma = 0;
+       list_for_each_entry_reverse(page, desc_pages, lru) {
+               page_virtual = kmap_atomic(page);
+               page_virtual[desc_per_page].ppn = desc_dma >> PAGE_SHIFT;
                kunmap_atomic(page_virtual);
+               desc_dma = dma_map_page(dev, page, 0, PAGE_SIZE,
+                                       DMA_TO_DEVICE);
+
+               if (unlikely(dma_mapping_error(dev, desc_dma)))
+                       goto out_err;
+       }
+       *first_dma = desc_dma;
 
        return 0;
 out_err:
-       list_for_each_entry_safe(page, next, desc_pages, lru) {
-               list_del_init(&page->lru);
-               __free_page(page);
-       }
+       vmw_gmr_free_descriptors(dev, DMA_ADDR_INVALID, desc_pages);
        return ret;
 }
 
-static inline void vmw_gmr_free_descriptors(struct list_head *desc_pages)
-{
-       struct page *page, *next;
-
-       list_for_each_entry_safe(page, next, desc_pages, lru) {
-               list_del_init(&page->lru);
-               __free_page(page);
-       }
-}
-
 static void vmw_gmr_fire_descriptors(struct vmw_private *dev_priv,
-                                    int gmr_id, struct list_head *desc_pages)
+                                    int gmr_id, dma_addr_t desc_dma)
 {
-       struct page *page;
-
-       if (unlikely(list_empty(desc_pages)))
-               return;
-
-       page = list_entry(desc_pages->next, struct page, lru);
-
        mutex_lock(&dev_priv->hw_mutex);
 
        vmw_write(dev_priv, SVGA_REG_GMR_ID, gmr_id);
        wmb();
-       vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, page_to_pfn(page));
+       vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, desc_dma >> PAGE_SHIFT);
        mb();
 
        mutex_unlock(&dev_priv->hw_mutex);
 
 }
 
-/**
- * FIXME: Adjust to the ttm lowmem / highmem storage to minimize
- * the number of used descriptors.
- */
-
-static unsigned long vmw_gmr_count_descriptors(struct page *pages[],
-                                       unsigned long num_pages)
-{
-       unsigned long prev_pfn = ~(0UL);
-       unsigned long pfn;
-       unsigned long descriptors = 0;
-
-       while (num_pages--) {
-               pfn = page_to_pfn(*pages++);
-               if (prev_pfn + 1 != pfn)
-                       ++descriptors;
-               prev_pfn = pfn;
-       }
-
-       return descriptors;
-}
-
 int vmw_gmr_bind(struct vmw_private *dev_priv,
-                struct page *pages[],
+                const struct vmw_sg_table *vsgt,
                 unsigned long num_pages,
                 int gmr_id)
 {
        struct list_head desc_pages;
+       dma_addr_t desc_dma = 0;
+       struct device *dev = dev_priv->dev->dev;
+       struct vmw_piter data_iter;
        int ret;
 
+       vmw_piter_start(&data_iter, vsgt, 0);
+
+       if (unlikely(!vmw_piter_next(&data_iter)))
+               return 0;
+
        if (likely(dev_priv->capabilities & SVGA_CAP_GMR2))
-               return vmw_gmr2_bind(dev_priv, pages, num_pages, gmr_id);
+               return vmw_gmr2_bind(dev_priv, &data_iter, num_pages, gmr_id);
 
        if (unlikely(!(dev_priv->capabilities & SVGA_CAP_GMR)))
                return -EINVAL;
 
-       if (vmw_gmr_count_descriptors(pages, num_pages) >
-           dev_priv->max_gmr_descriptors)
+       if (vsgt->num_regions > dev_priv->max_gmr_descriptors)
                return -EINVAL;
 
        INIT_LIST_HEAD(&desc_pages);
 
-       ret = vmw_gmr_build_descriptors(&desc_pages, pages, num_pages);
+       ret = vmw_gmr_build_descriptors(dev, &desc_pages, &data_iter,
+                                       num_pages, &desc_dma);
        if (unlikely(ret != 0))
                return ret;
 
-       vmw_gmr_fire_descriptors(dev_priv, gmr_id, &desc_pages);
-       vmw_gmr_free_descriptors(&desc_pages);
+       vmw_gmr_fire_descriptors(dev_priv, gmr_id, desc_dma);
+       vmw_gmr_free_descriptors(dev, desc_dma, &desc_pages);
 
        return 0;
 }