diff options
Diffstat (limited to 'drivers/infiniband/hw/ipath/ipath_user_pages.c')
-rw-r--r-- | drivers/infiniband/hw/ipath/ipath_user_pages.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/ipath/ipath_user_pages.c b/drivers/infiniband/hw/ipath/ipath_user_pages.c index e32fca9..413754b 100644 --- a/drivers/infiniband/hw/ipath/ipath_user_pages.c +++ b/drivers/infiniband/hw/ipath/ipath_user_pages.c @@ -90,6 +90,62 @@ bail: } /** + * ipath_map_page - a safety wrapper around pci_map_page() + * + * A dma_addr of all 0's is interpreted by the chip as "disabled". + * Unfortunately, it can also be a valid dma_addr returned on some + * architectures. + * + * The powerpc iommu assigns dma_addrs in ascending order, so we don't + * have to bother with retries or mapping a dummy page to insure we + * don't just get the same mapping again. + * + * I'm sure we won't be so lucky with other iommu's, so FIXME. + */ +dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page, + unsigned long offset, size_t size, int direction) +{ + dma_addr_t phys; + + phys = pci_map_page(hwdev, page, offset, size, direction); + + if (phys == 0) { + pci_unmap_page(hwdev, phys, size, direction); + phys = pci_map_page(hwdev, page, offset, size, direction); + /* + * FIXME: If we get 0 again, we should keep this page, + * map another, then free the 0 page. + */ + } + + return phys; +} + +/** + * ipath_map_single - a safety wrapper around pci_map_single() + * + * Same idea as ipath_map_page(). + */ +dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size, + int direction) +{ + dma_addr_t phys; + + phys = pci_map_single(hwdev, ptr, size, direction); + + if (phys == 0) { + pci_unmap_single(hwdev, phys, size, direction); + phys = pci_map_single(hwdev, ptr, size, direction); + /* + * FIXME: If we get 0 again, we should keep this page, + * map another, then free the 0 page. + */ + } + + return phys; +} + +/** * ipath_get_user_pages - lock user pages into memory * @start_page: the start page * @num_pages: the number of pages |