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[PATCH v5 0/4] MSI, of, irqchip/gicv3-its: Handle "msi-map" properties.

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  [PATCH v5 0/4] MSI, of, irqchip/gicv3-its: Handle "msi-map" properties. David Daney <ddaney.cavm@gmail.com> - 2015-10-09 00:20 +0200
    [PATCH v5 2/4] of/irq: Add new function of_msi_map_rid() David Daney <ddaney.cavm@gmail.com> - 2015-10-09 00:20 +0200

#1242818 — [PATCH v5 0/4] MSI, of, irqchip/gicv3-its: Handle "msi-map" properties.

From: David Daney <david.daney@cavium.com>

The first patch from Mark Rutland adds the OF device tree binding
description, which explains what we are attempting to do here.  For
MSI messages on GICv3 systems there is some side-band data that
accompanies the message, this data is specified in the OF device tree
"msi-map" property of the PCI host driver.

The second patch adds a parser to get the required information out of
the device tree.

The third patch creates the pci_msi_domain_get_msi_rid() function to
make it more convenient to generate the proper PCI/MSI requester id.

The final patch converts gicv3-its to use the new infrastructure.

Changes from v1: Factor out the device tree access code to a separate
function in drivers/of/irq.c

Changes from v2: Added the pci_msi_domain_get_msi_rid() patch to
generalize the support a bit more.

Changes from v3: Added Acked-by to 2/4.  Simplified and improved
pci_msi_domain_get_msi_rid() as suggested by Marc Zyngier in 3/4.  1/4
and 4/4 unchanged.

Changes from v4: Added Reviewed-by to 3/4 and 4/4

David Daney (3):
  of/irq: Add new function of_msi_map_rid()
  PCI/MSI:  Add helper function pci_msi_domain_get_msi_rid().
  irqchip/gic-v3-its:  Add handling of PCI requester id.

Mark Rutland (1):
  Docs: dt: Add PCI MSI map bindings

 Documentation/devicetree/bindings/pci/pci-msi.txt | 220 ++++++++++++++++++++++
 drivers/irqchip/irq-gic-v3-its-pci-msi.c          |   4 +-
 drivers/of/irq.c                                  |  84 +++++++++
 drivers/pci/msi.c                                 |  30 +++
 include/linux/msi.h                               |   1 +
 include/linux/of_irq.h                            |   7 +
 6 files changed, 343 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pci/pci-msi.txt

-- 
1.9.1

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#1242820 — [PATCH v5 2/4] of/irq: Add new function of_msi_map_rid()

From: David Daney <david.daney@cavium.com>

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>
---
 drivers/of/irq.c       | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of_irq.h |  7 +++++
 2 files changed, 91 insertions(+)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 55317fa..c90bd4e 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;
+}
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index 4bcbd58..8cd9334 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -75,6 +75,7 @@ static inline int of_irq_to_resource_table(struct device_node *dev,
 extern unsigned int irq_of_parse_and_map(struct device_node *node, int index);
 extern struct device_node *of_irq_find_parent(struct device_node *child);
 extern void of_msi_configure(struct device *dev, struct device_node *np);
+u32 of_msi_map_rid(struct device *dev, struct device_node *msi_np, u32 rid_in);
 
 #else /* !CONFIG_OF */
 static inline unsigned int irq_of_parse_and_map(struct device_node *dev,
@@ -87,6 +88,12 @@ static inline void *of_irq_find_parent(struct device_node *child)
 {
 	return NULL;
 }
+
+static inline u32 of_msi_map_rid(struct device *dev,
+				 struct device_node *msi_np, u32 rid_in)
+{
+	return rid_in;
+}
 #endif /* !CONFIG_OF */
 
 #endif /* __OF_IRQ_H */
-- 
1.9.1

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