of/irq: Break out msi-map lookup (again)

The PCI msi-map code is already doing double-duty translating IDs and
retrieving MSI parents, which unsurprisingly is the same functionality
we need for the identically-formatted PCI iommu-map property. Drag the
core parsing routine up yet another layer into the general OF-PCI code,
and further generalise it for either kind of lookup in either flavour
of map property.

Acked-by: Rob Herring <robh+dt@kernel.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index a2e68f740edacbe900af35b5875cb65e6e40771a..393fea85eb4ef89babde111e622166b441885eb5 100644 (file)
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
+#include <linux/of_pci.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 
@@ -592,87 +593,16 @@ static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
                            u32 rid_in)
 {
        struct device *parent_dev;
-       struct device_node *msi_controller_node;
-       struct device_node *msi_np = *np;
-       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);
-
-               if (rid_base & ~map_mask) {
-                       dev_err(parent_dev,
-                               "Invalid msi-map translation - msi-map-mask (0x%x) ignores rid-base (0x%x)\n",
-                               map_mask, rid_base);
-                       return rid_out;
-               }
-
-               msi_controller_node = of_find_node_by_phandle(phandle);
-
-               matched = (masked_rid >= rid_base &&
-                          masked_rid < rid_base + rid_len);
-               if (msi_np)
-                       matched &= msi_np == msi_controller_node;
-
-               if (matched && !msi_np) {
-                       *np = msi_np = msi_controller_node;
+       for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent)
+               if (!of_pci_map_rid(parent_dev->of_node, rid_in, "msi-map",
+                                   "msi-map-mask", np, &rid_out))
                        break;
-               }
-
-               of_node_put(msi_controller_node);
-               msi_map_len -= 4 * sizeof(__be32);
-               msi_map += 4;
-       }
-       if (!matched)
-               return rid_out;
-
-       rid_out = masked_rid - rid_base + 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;
 }
 

diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 589b30c68e1427efc280f13d0bbcaf660e816ab0..b58be12ab27770bbbe40c25eb220a96204c71d3d 100644 (file)
--- 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;
+}

diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index b969e944396223defb902c7e7f2ac1238b410585..7fd5cfce91403f0571335fc4b172d889e6ad371e 100644 (file)
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -17,6 +17,9 @@ int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
 int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
 int of_get_pci_domain_nr(struct device_node *node);
 void of_pci_check_probe_only(void);
+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);
 #else
 static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
 {
@@ -52,6 +55,13 @@ of_get_pci_domain_nr(struct device_node *node)
        return -1;
 }
 
+static inline 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)
+{
+       return -EINVAL;
+}
+
 static inline void of_pci_check_probe_only(void) { }
 #endif