summaryrefslogtreecommitdiff
path: root/drivers/of/irq.c
diff options
context:
space:
mode:
authorDavid Daney <david.daney@cavium.com>2015-10-09 01:10:48 +0300
committerMarc Zyngier <marc.zyngier@arm.com>2015-10-16 13:45:27 +0300
commit8db02d8b4089fa8098a170738e8ae7939aa8ae7a (patch)
treeea1896aed96b16e1b5e3f82a015c7067d66cd6ba /drivers/of/irq.c
parentb531566e4dced7566dfa2e4925ec8b6a8cb7806b (diff)
downloadlinux-8db02d8b4089fa8098a170738e8ae7939aa8ae7a.tar.xz
of/irq: Add new function of_msi_map_rid()
The device tree property "msi-map" specifies how to create the PCI requester id used in some MSI controllers. Add a new function of_msi_map_rid() that finds the msi-map property and applies its translation to a given requester id. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'drivers/of/irq.c')
-rw-r--r--drivers/of/irq.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 55317fa9c9dc..c90bd4ec3183 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -598,3 +598,87 @@ void of_msi_configure(struct device *dev, struct device_node *np)
d = irq_find_host(msi_np);
dev_set_msi_domain(dev, d);
}
+
+/**
+ * of_msi_map_rid - Map a MSI requester ID for a device.
+ * @dev: device for which the mapping is to be done.
+ * @msi_np: device node of the expected msi controller.
+ * @rid_in: unmapped MSI requester ID for the device.
+ *
+ * Walk up the device hierarchy looking for devices with a "msi-map"
+ * property. If found, apply the mapping to @rid_in.
+ *
+ * Returns the mapped MSI requester ID.
+ */
+u32 of_msi_map_rid(struct device *dev, struct device_node *msi_np, u32 rid_in)
+{
+ struct device *parent_dev;
+ struct device_node *msi_controller_node;
+ u32 map_mask, masked_rid, rid_base, msi_base, rid_len, phandle;
+ int msi_map_len;
+ bool matched;
+ u32 rid_out = rid_in;
+ const __be32 *msi_map = NULL;
+
+ /*
+ * Walk up the device parent links looking for one with a
+ * "msi-map" property.
+ */
+ for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
+ if (!parent_dev->of_node)
+ continue;
+
+ msi_map = of_get_property(parent_dev->of_node,
+ "msi-map", &msi_map_len);
+ if (!msi_map)
+ continue;
+
+ if (msi_map_len % (4 * sizeof(__be32))) {
+ dev_err(parent_dev, "Error: Bad msi-map length: %d\n",
+ msi_map_len);
+ return rid_out;
+ }
+ /* We have a good parent_dev and msi_map, let's use them. */
+ break;
+ }
+ if (!msi_map)
+ return rid_out;
+
+ /* The default is to select all bits. */
+ map_mask = 0xffffffff;
+
+ /*
+ * Can be overridden by "msi-map-mask" property. If
+ * of_property_read_u32() fails, the default is used.
+ */
+ of_property_read_u32(parent_dev->of_node, "msi-map-mask", &map_mask);
+
+ masked_rid = map_mask & rid_in;
+ matched = false;
+ while (!matched && msi_map_len >= 4 * sizeof(__be32)) {
+ rid_base = be32_to_cpup(msi_map + 0);
+ phandle = be32_to_cpup(msi_map + 1);
+ msi_base = be32_to_cpup(msi_map + 2);
+ rid_len = be32_to_cpup(msi_map + 3);
+
+ msi_controller_node = of_find_node_by_phandle(phandle);
+
+ matched = masked_rid >= rid_base &&
+ masked_rid < rid_base + rid_len &&
+ msi_np == msi_controller_node;
+
+ of_node_put(msi_controller_node);
+ msi_map_len -= 4 * sizeof(__be32);
+ msi_map += 4;
+ }
+ if (!matched)
+ return rid_out;
+
+ rid_out = masked_rid + msi_base;
+ dev_dbg(dev,
+ "msi-map at: %s, using mask %08x, rid-base: %08x, msi-base: %08x, length: %08x, rid: %08x -> %08x\n",
+ dev_name(parent_dev), map_mask, rid_base, msi_base,
+ rid_len, rid_in, rid_out);
+
+ return rid_out;
+}