drm/nouveau: remove allocations from gart populate() hook

Since some somewhat questionable changes a while back, TTM provides a
completely empty array of struct dma_address that stays around for the
entire lifetime of the TTM object.

Lets use this array, *always*, rather than wasting yet more memory on
another array who's purpose is identical, as well as yet another bool array
of the same size saying *which* of the previous two arrays to use...

This change will also solve the high order allocation failures seen by
some people while using nouveau.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_sgdma.c b/drivers/gpu/drm/nouveau/nouveau_sgdma.c
index 2706cb3d871a2cdafd84da5b3bb73f5c39f01fe8..b75258a9fe44d544521431133ecd64ec0136637d 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_sgdma.c
+++ b/drivers/gpu/drm/nouveau/nouveau_sgdma.c
@@ -12,8 +12,8 @@ struct nouveau_sgdma_be {
        struct drm_device *dev;
 
        dma_addr_t *pages;
-       bool *ttm_alloced;
        unsigned nr_pages;
+       bool unmap_pages;
 
        u64 offset;
        bool bound;
@@ -26,43 +26,28 @@ nouveau_sgdma_populate(struct ttm_backend *be, unsigned long num_pages,
 {
        struct nouveau_sgdma_be *nvbe = (struct nouveau_sgdma_be *)be;
        struct drm_device *dev = nvbe->dev;
+       int i;
 
        NV_DEBUG(nvbe->dev, "num_pages = %ld\n", num_pages);
 
-       if (nvbe->pages)
-               return -EINVAL;
-
-       nvbe->pages = kmalloc(sizeof(dma_addr_t) * num_pages, GFP_KERNEL);
-       if (!nvbe->pages)
-               return -ENOMEM;
+       nvbe->pages = dma_addrs;
+       nvbe->nr_pages = num_pages;
+       nvbe->unmap_pages = true;
 
-       nvbe->ttm_alloced = kmalloc(sizeof(bool) * num_pages, GFP_KERNEL);
-       if (!nvbe->ttm_alloced) {
-               kfree(nvbe->pages);
-               nvbe->pages = NULL;
-               return -ENOMEM;
+       /* this code path isn't called and is incorrect anyways */
+       if (0) { /* dma_addrs[0] != DMA_ERROR_CODE) { */
+               nvbe->unmap_pages = false;
+               return 0;
        }
 
-       nvbe->nr_pages = 0;
-       while (num_pages--) {
-               /* this code path isn't called and is incorrect anyways */
-               if (0) { /*dma_addrs[nvbe->nr_pages] != DMA_ERROR_CODE)*/
-                       nvbe->pages[nvbe->nr_pages] =
-                                       dma_addrs[nvbe->nr_pages];
-                       nvbe->ttm_alloced[nvbe->nr_pages] = true;
-               } else {
-                       nvbe->pages[nvbe->nr_pages] =
-                               pci_map_page(dev->pdev, pages[nvbe->nr_pages], 0,
-                                    PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
-                       if (pci_dma_mapping_error(dev->pdev,
-                                                 nvbe->pages[nvbe->nr_pages])) {
-                               be->func->clear(be);
-                               return -EFAULT;
-                       }
-                       nvbe->ttm_alloced[nvbe->nr_pages] = false;
+       for (i = 0; i < num_pages; i++) {
+               nvbe->pages[i] = pci_map_page(dev->pdev, pages[i], 0,
+                                             PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+               if (pci_dma_mapping_error(dev->pdev, nvbe->pages[i])) {
+                       nvbe->nr_pages = --i;
+                       be->func->clear(be);
+                       return -EFAULT;
                }
-
-               nvbe->nr_pages++;
        }
 
        return 0;
@@ -72,25 +57,16 @@ static void
 nouveau_sgdma_clear(struct ttm_backend *be)
 {
        struct nouveau_sgdma_be *nvbe = (struct nouveau_sgdma_be *)be;
-       struct drm_device *dev;
-
-       if (nvbe && nvbe->pages) {
-               dev = nvbe->dev;
-               NV_DEBUG(dev, "\n");
+       struct drm_device *dev = nvbe->dev;
 
-               if (nvbe->bound)
-                       be->func->unbind(be);
+       if (nvbe->bound)
+               be->func->unbind(be);
 
+       if (nvbe->unmap_pages) {
                while (nvbe->nr_pages--) {
-                       if (!nvbe->ttm_alloced[nvbe->nr_pages])
-                               pci_unmap_page(dev->pdev, nvbe->pages[nvbe->nr_pages],
+                       pci_unmap_page(dev->pdev, nvbe->pages[nvbe->nr_pages],
                                       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
                }
-               kfree(nvbe->pages);
-               kfree(nvbe->ttm_alloced);
-               nvbe->pages = NULL;
-               nvbe->ttm_alloced = NULL;
-               nvbe->nr_pages = 0;
        }
 }