The dma_ranges list field of PCI host bridge structure has resource entries in sorted order representing address ranges allowed for DMA transfers.
Process the list and reserve IOVA addresses that are not present in its resource entries (ie DMA memory holes) to prevent allocating IOVA addresses that cannot be accessed by PCI devices. Based-on-patch-by: Oza Pawandeep <[email protected]> Signed-off-by: Srinath Mannam <[email protected]> Signed-off-by: Lorenzo Pieralisi <[email protected]> Reviewed-by: Oza Pawandeep <[email protected]> Acked-by: Robin Murphy <[email protected]> --- drivers/iommu/dma-iommu.c | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 77aabe6..954ae11 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -206,12 +206,13 @@ static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, return 0; } -static void iova_reserve_pci_windows(struct pci_dev *dev, +static int iova_reserve_pci_windows(struct pci_dev *dev, struct iova_domain *iovad) { struct pci_host_bridge *bridge = pci_find_host_bridge(dev->bus); struct resource_entry *window; unsigned long lo, hi; + phys_addr_t start = 0, end; resource_list_for_each_entry(window, &bridge->windows) { if (resource_type(window->res) != IORESOURCE_MEM) @@ -221,6 +222,31 @@ static void iova_reserve_pci_windows(struct pci_dev *dev, hi = iova_pfn(iovad, window->res->end - window->offset); reserve_iova(iovad, lo, hi); } + + /* Get reserved DMA windows from host bridge */ + resource_list_for_each_entry(window, &bridge->dma_ranges) { + end = window->res->start - window->offset; +resv_iova: + if (end > start) { + lo = iova_pfn(iovad, start); + hi = iova_pfn(iovad, end); + reserve_iova(iovad, lo, hi); + } else { + /* dma_ranges list should be sorted */ + dev_err(&dev->dev, "Failed to reserve IOVA\n"); + return -EINVAL; + } + + start = window->res->end - window->offset + 1; + /* If window is last entry */ + if (window->node.next == &bridge->dma_ranges && + end != ~(dma_addr_t)0) { + end = ~(dma_addr_t)0; + goto resv_iova; + } + } + + return 0; } static int iova_reserve_iommu_regions(struct device *dev, @@ -232,8 +258,11 @@ static int iova_reserve_iommu_regions(struct device *dev, LIST_HEAD(resv_regions); int ret = 0; - if (dev_is_pci(dev)) - iova_reserve_pci_windows(to_pci_dev(dev), iovad); + if (dev_is_pci(dev)) { + ret = iova_reserve_pci_windows(to_pci_dev(dev), iovad); + if (ret) + return ret; + } iommu_get_resv_regions(dev, &resv_regions); list_for_each_entry(region, &resv_regions, list) { -- 2.7.4 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
