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authorNipun Gupta <nipun.gupta@nxp.com>2018-09-10 19:19:16 +0530
committerJoerg Roedel <jroedel@suse.de>2018-09-25 09:47:52 +0200
commit2a6db719c92dbfe43c9eea7e4358ea2e51b5004e (patch)
tree4c685a9457b305ca4ce8f620e85c0a34de97ca0c /drivers/of/base.c
parentc9d8d661ece808f987e606d73d57e3bd6849ac6a (diff)
downloadlinux-2a6db719c92dbfe43c9eea7e4358ea2e51b5004e.tar.bz2
iommu/of: make of_pci_map_rid() available for other devices too
iommu-map property is also used by devices with fsl-mc. This patch moves the of_pci_map_rid to generic location, so that it can be used by other busses too. 'of_pci_map_rid' is renamed here to 'of_map_rid' and there is no functional change done in the API. Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com> Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/of/base.c')
-rw-r--r--drivers/of/base.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 74eaedd5b860..90bf7d9fa17b 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2045,3 +2045,105 @@ int of_find_last_cache_level(unsigned int cpu)
return cache_level;
}
+
+/**
+ * of_map_rid - Translate a requester ID through a downstream mapping.
+ * @np: root complex device node.
+ * @rid: device 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 device 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_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("%pOF: Error: Bad %s length: %d\n", np,
+ 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("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
+ np, 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("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
+ np, map_name, map_mask, rid_base, out_base,
+ rid_len, rid, masked_rid - rid_base + out_base);
+ return 0;
+ }
+
+ pr_err("%pOF: Invalid %s translation - no match for rid 0x%x on %pOF\n",
+ np, map_name, rid, target && *target ? *target : NULL);
+ return -EFAULT;
+}
+EXPORT_SYMBOL_GPL(of_map_rid);