Re: [PATCH 5/5] nouveau/ttm/PCIe: Use dma_addr if TTM has set it.

On Fri, Jan 07, 2011 at 12:11:44PM -0500, Konrad Rzeszutek Wilk wrote:

If the TTM layer has used the DMA API to setup pages that are TTM_PAGE_FLAG_DMA32 (look at patch titled: "ttm: Utilize the dma_addr_t array for pages that are to in DMA32 pool."), lets use it when programming the GART in the PCIe type cards.

This patch skips doing the pci_map_page (and pci_unmap_page) if there is a DMA addresses passed in for that page. If the dma_address is zero (or DMA_ERROR_CODE), then we continue on with our old behaviour.

Hey Ben and Jerome,

I should have CC-ed you guys earlier but missed that and instead just CC-ed the mailing list. I was wondering what your thoughts are about this patchset? Thomas took a look at the patchset and he is OK but more eyes never hurt.

Signed-off-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com

drivers/gpu/drm/nouveau/nouveau_sgdma.c | 28 +++++++++++++++++++++------- 1 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_sgdma.c b/drivers/gpu/drm/nouveau/nouveau_sgdma.c index edc140a..bbdd982 100644 --- a/drivers/gpu/drm/nouveau/nouveau_sgdma.c +++ b/drivers/gpu/drm/nouveau/nouveau_sgdma.c @@ -12,6 +12,7 @@ struct nouveau_sgdma_be { struct drm_device *dev;

dma_addr_t *pages;

• bool *ttm_alloced; unsigned nr_pages;

  unsigned pte_start;

@@ -35,15 +36,25 @@ nouveau_sgdma_populate(struct ttm_backend *be, unsigned long num_pages, if (!nvbe->pages) return -ENOMEM;

• nvbe->ttm_alloced = kmalloc(sizeof(bool) * num_pages, GFP_KERNEL);
• if (!nvbe->ttm_alloced)

• return -ENOMEM;
  

• nvbe->nr_pages = 0; while (num_pages--) {

• nvbe->pages[nvbe->nr_pages] =
  

• 	pci_map_page(dev->pdev, pages[nvbe->nr_pages], 0,
  

• if (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;
  

• 	if (pci_dma_mapping_error(dev->pdev,
  

• 				  nvbe->pages[nvbe->nr_pages])) {
  

• 		be->func->clear(be);
  

• 		return -EFAULT;
  

• 	}
  

  }

  nvbe->nr_pages++;

@@ -66,11 +77,14 @@ nouveau_sgdma_clear(struct ttm_backend *be) be->func->unbind(be);

while (nvbe->nr_pages--) {

• 	pci_unmap_page(dev->pdev, nvbe->pages[nvbe->nr_pages],
  

• 	if (!nvbe->ttm_alloced[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; }

}

1.7.1