From: John Garry <john.ga...@huawei.com> On some platforms msi-controller address regions have to be excluded from normal IOVA allocation in that they are detected and decoded in a HW specific way by system components and so they cannot be considered normal IOVA address space.
Add a helper function that retrieves msi address regions through device tree msi mapping, so that these regions will not be translated by IOMMU and will be excluded from IOVA allocations. Signed-off-by: John Garry <john.ga...@huawei.com> [Shameer: Modified msi-parent retrieval logic] Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com> --- drivers/iommu/of_iommu.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_iommu.h | 10 +++++ 2 files changed, 105 insertions(+) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index e60e3db..ffd7fb7 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -21,6 +21,7 @@ #include <linux/iommu.h> #include <linux/limits.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/of_iommu.h> #include <linux/of_pci.h> #include <linux/slab.h> @@ -138,6 +139,14 @@ static int of_iommu_xlate(struct device *dev, return ops->of_xlate(dev, iommu_spec); } +static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data) +{ + u32 *rid = data; + + *rid = alias; + return 0; +} + struct of_pci_iommu_alias_info { struct device *dev; struct device_node *np; @@ -163,6 +172,73 @@ static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data) return info->np == pdev->bus->dev.of_node; } +static int of_iommu_alloc_resv_region(struct device_node *np, + struct list_head *head) +{ + int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; + struct iommu_resv_region *region; + struct resource res; + int err; + + err = of_address_to_resource(np, 0, &res); + if (err) + return err; + + region = iommu_alloc_resv_region(res.start, resource_size(&res), + prot, IOMMU_RESV_MSI); + if (!region) + return -ENOMEM; + + list_add_tail(®ion->list, head); + + return 0; +} + +static int of_pci_msi_get_resv_regions(struct device *dev, + struct list_head *head) +{ + struct device_node *msi_np; + struct device *pdev; + u32 rid; + int err, resv = 0; + + pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, &rid); + + for_each_node_with_property(msi_np, "msi-controller") { + for (pdev = dev; pdev; pdev = pdev->parent) { + if (!of_pci_map_rid(pdev->of_node, rid, "msi-map", + "msi-map-mask", &msi_np, NULL)) { + + err = of_iommu_alloc_resv_region(msi_np, head); + if (err) + return err; + resv++; + } + } + } + + return resv; +} + +static int of_platform_msi_get_resv_regions(struct device *dev, + struct list_head *head) +{ + struct of_phandle_args args; + int err, resv = 0; + + while (!of_parse_phandle_with_args(dev->of_node, "msi-parent", + "#msi-cells", resv, &args)) { + + err = of_iommu_alloc_resv_region(args.np, head); + of_node_put(args.np); + if (err) + return err; + resv++; + } + + return resv; +} + const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np) { @@ -235,6 +311,25 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, return ops; } +/** + * of_iommu_msi_get_resv_regions - Reserved region driver helper + * @dev: Device from iommu_get_resv_regions() + * @head: Reserved region list from iommu_get_resv_regions() + * + * Returns: Number of reserved regions on success (0 if no associated + * msi parent), appropriate error value otherwise. + */ +int of_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head) +{ + + if (dev_is_pci(dev)) + return of_pci_msi_get_resv_regions(dev, head); + else if (dev->of_node) + return of_platform_msi_get_resv_regions(dev, head); + + return 0; +} + static int __init of_iommu_init(void) { struct device_node *np; diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h index 13394ac..9267772 100644 --- a/include/linux/of_iommu.h +++ b/include/linux/of_iommu.h @@ -14,6 +14,9 @@ extern int of_get_dma_window(struct device_node *dn, const char *prefix, extern const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np); +extern int of_iommu_msi_get_resv_regions(struct device *dev, + struct list_head *head); + #else static inline int of_get_dma_window(struct device_node *dn, const char *prefix, @@ -29,6 +32,13 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev, return NULL; } +static int of_iommu_msi_get_resv_regions(struct device *dev, + struct list_head *head) +{ + return -ENODEV; +} + + #endif /* CONFIG_OF_IOMMU */ extern struct of_device_id __iommu_of_table; -- 1.9.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu