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> Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com> --- drivers/iommu/of_iommu.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_iommu.h | 10 ++++ 2 files changed, 127 insertions(+) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 8cb6082..f2d1a76 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> @@ -246,6 +247,122 @@ 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() + * @list: 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) +{ + int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; + struct iommu_resv_region *region; + struct device_node *np; + struct resource res; + int i, resv = 0, mappings = 0; + + if (dev_is_pci(dev)) { + struct device *dma_dev, *bridge; + struct of_phandle_args iommu_spec; + struct pci_dev *pdev = to_pci_dev(dev); + int err, count; + u32 rid, map_mask; + const __be32 *msi_map; + + bridge = pci_get_host_bridge_device(pdev); + dma_dev = bridge->parent; + pci_put_host_bridge_device(bridge); + + if (!dma_dev->of_node) + return -ENODEV; + + iommu_spec.args_count = 1; + np = iommu_spec.np = dma_dev->of_node; + pci_for_each_dma_alias(pdev, __get_pci_rid, &iommu_spec); + + rid = iommu_spec.args[0]; + if (!of_property_read_u32(np, "msi-map-mask", &map_mask)) + rid &= map_mask; + + msi_map = of_get_property(np, "msi-map", NULL); + if (!msi_map) + return -ENODEV; + + mappings = of_count_phandle_with_args(np, "msi-map", NULL) / 4; + + for (i = 0, count = mappings; i < count; i++, msi_map += 4) { + struct device_node *msi_node; + u32 rid_base, rid_len, phandle; + + rid_base = be32_to_cpup(msi_map + 0); + phandle = be32_to_cpup(msi_map + 1); + rid_len = be32_to_cpup(msi_map + 3); + + /* check rid is within range */ + if (rid < rid_base || rid >= rid_base + rid_len) { + mappings--; + continue; + } + + msi_node = of_find_node_by_phandle(phandle); + if (!msi_node) + return -ENODEV; + + err = of_address_to_resource(msi_node, 0, &res); + of_node_put(msi_node); + if (err) + return err; + + region = iommu_alloc_resv_region(res.start, + resource_size(&res), + prot, IOMMU_RESV_MSI); + if (region) { + list_add_tail(®ion->list, head); + resv++; + } + } + } else if (dev->of_node) { + struct device_node *msi_np; + int index = 0; + int tuples; + + np = dev->of_node; + + tuples = of_count_phandle_with_args(np, "msi-parent", NULL); + + while (index < tuples) { + int msi_cells = 0; + int err; + + msi_np = of_parse_phandle(np, "msi-parent", index); + if (!msi_np) + return -ENODEV; + + of_property_read_u32(msi_np, "#msi-cells", &msi_cells); + + err = of_address_to_resource(msi_np, 0, &res); + of_node_put(msi_np); + if (err) + return err; + + mappings++; + + region = iommu_alloc_resv_region(res.start, + resource_size(&res), + prot, IOMMU_RESV_MSI); + if (region) { + list_add_tail(®ion->list, head); + resv++; + } + index += 1 + msi_cells; + } + } + + return (resv == mappings) ? resv : -ENODEV; +} + 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