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iommu/dma: Reserve IOVA for PCIe inaccessible DMA address

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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-a-patch-by: Oza Pawandeep <oza.oza@broadcom.com>
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
This commit is contained in:
Srinath Mannam 2019-05-03 19:35:33 +05:30 committed by Bjorn Helgaas
parent e80a91ad30
commit aadad097cd
1 changed files with 32 additions and 3 deletions
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35
drivers/iommu/dma-iommu.c
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@ -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) {