[PATCH 02/12] of/irq: Break out msi-map lookup (again)
Robin Murphy
robin.murphy at arm.com
Mon Feb 29 05:46:11 PST 2016
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.
CC: Rob Herring <robh+dt at kernel.org>
CC: Frank Rowand <frowand.list at gmail.com>
CC: Marc Zyngier <marc.zyngier at arm.com>
CC: David Daney <david.daney at cavium.com>
Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
drivers/of/irq.c | 70 ++-------------------------------
drivers/of/of_pci.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of_pci.h | 8 ++++
3 files changed, 114 insertions(+), 66 deletions(-)
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index e7bfc17..0c9118d 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -24,6 +24,7 @@
#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>
@@ -586,13 +587,7 @@ 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
@@ -602,71 +597,14 @@ static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
if (!parent_dev->of_node)
continue;
- msi_map = of_get_property(parent_dev->of_node,
- "msi-map", &msi_map_len);
- if (!msi_map)
+ if (!of_property_read_bool(parent_dev->of_node, "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. */
+ of_pci_map_rid(parent_dev->of_node, "msi-map", rid_in, np,
+ &rid_out);
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;
- 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 b1449f7..15c4a64b 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -307,3 +307,105 @@ 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 */
+
+#define MASK_NAME_LEN 32 /* Safely longer than "iommu-map-mask" */
+
+/**
+ * of_pci_map_rid - Translate a requester ID through a downstream mapping.
+ * @np: root complex device node.
+ * @map_name: property name of the map 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. @target or @id_out may
+ * be NULL if not required. If @target points to a device node pointer, only
+ * entries targeting that node will be matched; if it points to a NULL
+ * value, it will receive the device node for the first matching target entry,
+ * with a reference held.
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_pci_map_rid(struct device_node *np, const char *map_name, u32 rid_in,
+ struct device_node **target, u32 *rid_out)
+{
+ u32 map_mask, masked_rid;
+ int map_len;
+ const __be32 *map = NULL;
+ char mask_name[MASK_NAME_LEN];
+
+ if (!np || !map_name || (!target && !rid_out))
+ return -EINVAL;
+
+ map = of_get_property(np, map_name, &map_len);
+ if (!map) {
+ if (target)
+ return -ENODEV;
+ /* Otherwise, no map implies no translation */
+ *rid_out = rid_in;
+ 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.
+ */
+ snprintf(mask_name, MASK_NAME_LEN, "%s-mask", map_name);
+ of_property_read_u32(np, mask_name, &map_mask);
+
+ masked_rid = map_mask & rid_in;
+ 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 -EINVAL;
+ }
+
+ 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 (rid_out)
+ *rid_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_in, *rid_out);
+ return 0;
+ }
+
+ pr_err("%s: Invalid %s translation - no match for rid 0x%x on %s\n",
+ np->full_name, map_name, rid_in,
+ target && *target ? (*target)->full_name : "any target");
+ return -EINVAL;
+}
diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index f6e9e85..070f883 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -17,6 +17,8 @@ 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, const char *map_name, u32 rid_in,
+ struct device_node **target, u32 *rid_out);
#else
static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
{
@@ -52,6 +54,12 @@ of_get_pci_domain_nr(struct device_node *node)
return -1;
}
+static inline int of_pci_map_rid(struct device_node *np, const char *map_name,
+ u32 rid_in, struct device_node **target, u32 *rid_out)
+{
+ return -EINVAL;
+}
+
static inline void of_pci_check_probe_only(void) { }
#endif
--
2.7.2.333.g70bd996.dirty
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