diff options
Diffstat (limited to 'drivers/of/of_pci.c')
| -rw-r--r-- | drivers/of/of_pci.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index 589b30c68e14..b58be12ab277 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -308,3 +308,105 @@ struct msi_controller *of_pci_find_msi_chip_by_node(struct device_node *of_node) EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node); #endif /* CONFIG_PCI_MSI */ + +/** + * of_pci_map_rid - Translate a requester ID through a downstream mapping. + * @np: root complex device node. + * @rid: PCI requester ID to map. + * @map_name: property name of the map to use. + * @map_mask_name: optional property name of the mask to use. + * @target: optional pointer to a target device node. + * @id_out: optional pointer to receive the translated ID. + * + * Given a PCI requester ID, look up the appropriate implementation-defined + * platform ID and/or the target device which receives transactions on that + * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or + * @id_out may be NULL if only the other is required. If @target points to + * a non-NULL device node pointer, only entries targeting that node will be + * matched; if it points to a NULL value, it will receive the device node of + * the first matching target phandle, with a reference held. + * + * Return: 0 on success or a standard error code on failure. + */ +int of_pci_map_rid(struct device_node *np, u32 rid, + const char *map_name, const char *map_mask_name, + struct device_node **target, u32 *id_out) +{ + u32 map_mask, masked_rid; + int map_len; + const __be32 *map = NULL; + + if (!np || !map_name || (!target && !id_out)) + return -EINVAL; + + map = of_get_property(np, map_name, &map_len); + if (!map) { + if (target) + return -ENODEV; + /* Otherwise, no map implies no translation */ + *id_out = rid; + return 0; + } + + if (!map_len || map_len % (4 * sizeof(*map))) { + pr_err("%s: Error: Bad %s length: %d\n", np->full_name, + map_name, map_len); + return -EINVAL; + } + + /* The default is to select all bits. */ + map_mask = 0xffffffff; + + /* + * Can be overridden by "{iommu,msi}-map-mask" property. + * If of_property_read_u32() fails, the default is used. + */ + if (map_mask_name) + of_property_read_u32(np, map_mask_name, &map_mask); + + masked_rid = map_mask & rid; + for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) { + struct device_node *phandle_node; + u32 rid_base = be32_to_cpup(map + 0); + u32 phandle = be32_to_cpup(map + 1); + u32 out_base = be32_to_cpup(map + 2); + u32 rid_len = be32_to_cpup(map + 3); + + if (rid_base & ~map_mask) { + pr_err("%s: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n", + np->full_name, map_name, map_name, + map_mask, rid_base); + return -EFAULT; + } + + if (masked_rid < rid_base || masked_rid >= rid_base + rid_len) + continue; + + phandle_node = of_find_node_by_phandle(phandle); + if (!phandle_node) + return -ENODEV; + + if (target) { + if (*target) + of_node_put(phandle_node); + else + *target = phandle_node; + + if (*target != phandle_node) + continue; + } + + if (id_out) + *id_out = masked_rid - rid_base + out_base; + + pr_debug("%s: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n", + np->full_name, map_name, map_mask, rid_base, out_base, + rid_len, rid, *id_out); + return 0; + } + + pr_err("%s: Invalid %s translation - no match for rid 0x%x on %s\n", + np->full_name, map_name, rid, + target && *target ? (*target)->full_name : "any target"); + return -EFAULT; +} |