[PATCH v7 22/22] iommu/dma: Avoid PCI host bridge windows
From: Robin Murphy <hidden>
Date: 2016-09-12 16:14:00
Also in:
linux-arm-kernel, linux-iommu
Subsystem:
arm64 port (aarch64 architecture), drm drivers, drm drivers for exynos, iommu dma-api layer, iommu subsystem, the rest · Maintainers:
Catalin Marinas, Will Deacon, David Airlie, Simona Vetter, Inki Dae, Seung-Woo Kim, Kyungmin Park, Robin Murphy, Joerg Roedel, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-09-15 · Re: [PATCH v7 22/22] iommu/dma: Avoid PCI host bridge windows · Marek Szyprowski <hidden>
- 2016-09-14 · Re: [PATCH v7 22/22] iommu/dma: Avoid PCI host bridge windows · Robin Murphy <hidden>
- 2016-09-14 · Re: [PATCH v7 22/22] iommu/dma: Avoid PCI host bridge windows · Marek Szyprowski <hidden>
- 2016-09-14 · Re: [PATCH v7 22/22] iommu/dma: Avoid PCI host bridge windows · Robin Murphy <hidden>
- 2016-09-14 · Re: [PATCH v7 22/22] iommu/dma: Avoid PCI host bridge windows · Marek Szyprowski <hidden>
With our DMA ops enabled for PCI devices, we should avoid allocating IOVAs which a host bridge might misinterpret as peer-to-peer DMA and lead to faults, corruption or other badness. To be safe, punch out holes for all of the relevant host bridge's windows when initialising a DMA domain for a PCI device. CC: Marek Szyprowski <redacted> CC: Inki Dae <redacted> Reported-by: Lorenzo Pieralisi <redacted> Signed-off-by: Robin Murphy <redacted> --- - Squash in the previous drm/exynos fixup - If need be, this one can probably wait --- arch/arm64/mm/dma-mapping.c | 2 +- drivers/gpu/drm/exynos/exynos_drm_iommu.h | 2 +- drivers/iommu/dma-iommu.c | 25 ++++++++++++++++++++++++- include/linux/dma-iommu.h | 3 ++- 4 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index c4284c432ae8..610d8e53011e 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c@@ -827,7 +827,7 @@ static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops, * then the IOMMU core will have already configured a group for this * device, and allocated the default domain for that group. */ - if (!domain || iommu_dma_init_domain(domain, dma_base, size)) { + if (!domain || iommu_dma_init_domain(domain, dma_base, size, dev)) { pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n", dev_name(dev)); return false;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.h b/drivers/gpu/drm/exynos/exynos_drm_iommu.h
index c8de4913fdbe..87f6b5672e11 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_iommu.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.h@@ -66,7 +66,7 @@ static inline int __exynos_iommu_create_mapping(struct exynos_drm_private *priv, if (ret) goto free_domain; - ret = iommu_dma_init_domain(domain, start, size); + ret = iommu_dma_init_domain(domain, start, size, NULL); if (ret) goto put_cookie;
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4329d18080cf..c5ab8667e6f2 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c@@ -27,6 +27,7 @@ #include <linux/iova.h> #include <linux/irq.h> #include <linux/mm.h> +#include <linux/pci.h> #include <linux/scatterlist.h> #include <linux/vmalloc.h>
@@ -103,18 +104,38 @@ void iommu_put_dma_cookie(struct iommu_domain *domain) } EXPORT_SYMBOL(iommu_put_dma_cookie); +static void 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; + + resource_list_for_each_entry(window, &bridge->windows) { + if (resource_type(window->res) != IORESOURCE_MEM && + resource_type(window->res) != IORESOURCE_IO) + continue; + + lo = iova_pfn(iovad, window->res->start - window->offset); + hi = iova_pfn(iovad, window->res->end - window->offset); + reserve_iova(iovad, lo, hi); + } +} + /** * iommu_dma_init_domain - Initialise a DMA mapping domain * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() * @base: IOVA at which the mappable address space starts * @size: Size of IOVA space + * @dev: Device the domain is being initialised for * * @base and @size should be exact multiples of IOMMU page granularity to * avoid rounding surprises. If necessary, we reserve the page at address 0 * to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but * any change which could make prior IOVAs invalid will fail. */ -int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size) +int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, + u64 size, struct device *dev) { struct iova_domain *iovad = cookie_iovad(domain); unsigned long order, base_pfn, end_pfn;
@@ -152,6 +173,8 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size iovad->dma_32bit_pfn = end_pfn; } else { init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn); + if (dev && dev_is_pci(dev)) + iova_reserve_pci_windows(to_pci_dev(dev), iovad); } return 0; }
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 5ee806e41b5c..32c589062bd9 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h@@ -30,7 +30,8 @@ int iommu_get_dma_cookie(struct iommu_domain *domain); void iommu_put_dma_cookie(struct iommu_domain *domain); /* Setup call for arch DMA mapping code */ -int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size); +int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, + u64 size, struct device *dev); /* General helpers for DMA-API <-> IOMMU-API interaction */ int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
--
2.8.1.dirty
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