Merge tag 'msi-map-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Support for msi-map, and msi-parent update from Marc Zyngier:

- New map-map property to describe the remapping of requester-ids,
  and the routing of MSIs to controllers
- New hooks to make MSI domains per-device if required
- Extension of msi-parent to provide sideband information
- Extensive documentation for both msi-map and msi-parent

Documentation/devicetree/bindings/pci/pci-msi.txt

@@ -0,0 +1,220 @@
+This document describes the generic device tree binding for describing the
+relationship between PCI devices and MSI controllers.
+
+Each PCI device under a root complex is uniquely identified by its Requester ID
+(AKA RID). A Requester ID is a triplet of a Bus number, Device number, and
+Function number.
+
+For the purpose of this document, when treated as a numeric value, a RID is
+formatted such that:
+
+* Bits [15:8] are the Bus number.
+* Bits [7:3] are the Device number.
+* Bits [2:0] are the Function number.
+* Any other bits required for padding must be zero.
+
+MSIs may be distinguished in part through the use of sideband data accompanying
+writes. In the case of PCI devices, this sideband data may be derived from the
+Requester ID. A mechanism is required to associate a device with both the MSI
+controllers it can address, and the sideband data that will be associated with
+its writes to those controllers.
+
+For generic MSI bindings, see
+Documentation/devicetree/bindings/interrupt-controller/msi.txt.
+
+
+PCI root complex
+================
+
+Optional properties
+-------------------
+
+- msi-map: Maps a Requester ID to an MSI controller and associated
+  msi-specifier data. The property is an arbitrary number of tuples of
+  (rid-base,msi-controller,msi-base,length), where:
+
+  * rid-base is a single cell describing the first RID matched by the entry.
+
+  * msi-controller is a single phandle to an MSI controller
+
+  * msi-base is an msi-specifier describing the msi-specifier produced for the
+    first RID matched by the entry.
+
+  * length is a single cell describing how many consecutive RIDs are matched
+    following the rid-base.
+
+  Any RID r in the interval [rid-base, rid-base + length) is associated with
+  the listed msi-controller, with the msi-specifier (r - rid-base + msi-base).
+
+- msi-map-mask: A mask to be applied to each Requester ID prior to being mapped
+  to an msi-specifier per the msi-map property.
+
+- msi-parent: Describes the MSI parent of the root complex itself. Where
+  the root complex and MSI controller do not pass sideband data with MSI
+  writes, this property may be used to describe the MSI controller(s)
+  used by PCI devices under the root complex, if defined as such in the
+  binding for the root complex.
+
+
+Example (1)
+===========
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	msi: msi-controller@a {
+		reg = <0xa 0x1>;
+		compatible = "vendor,some-controller";
+		msi-controller;
+		#msi-cells = <1>;
+	};
+
+	pci: pci@f {
+		reg = <0xf 0x1>;
+		compatible = "vendor,pcie-root-complex";
+		device_type = "pci";
+
+		/*
+		 * The sideband data provided to the MSI controller is
+		 * the RID, identity-mapped.
+		 */
+		msi-map = <0x0 &msi_a 0x0 0x10000>,
+	};
+};
+
+
+Example (2)
+===========
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	msi: msi-controller@a {
+		reg = <0xa 0x1>;
+		compatible = "vendor,some-controller";
+		msi-controller;
+		#msi-cells = <1>;
+	};
+
+	pci: pci@f {
+		reg = <0xf 0x1>;
+		compatible = "vendor,pcie-root-complex";
+		device_type = "pci";
+
+		/*
+		 * The sideband data provided to the MSI controller is
+		 * the RID, masked to only the device and function bits.
+		 */
+		msi-map = <0x0 &msi_a 0x0 0x100>,
+		msi-map-mask = <0xff>
+	};
+};
+
+
+Example (3)
+===========
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	msi: msi-controller@a {
+		reg = <0xa 0x1>;
+		compatible = "vendor,some-controller";
+		msi-controller;
+		#msi-cells = <1>;
+	};
+
+	pci: pci@f {
+		reg = <0xf 0x1>;
+		compatible = "vendor,pcie-root-complex";
+		device_type = "pci";
+
+		/*
+		 * The sideband data provided to the MSI controller is
+		 * the RID, but the high bit of the bus number is
+		 * ignored.
+		 */
+		msi-map = <0x0000 &msi 0x0000 0x8000>,
+			  <0x8000 &msi 0x0000 0x8000>;
+	};
+};
+
+
+Example (4)
+===========
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	msi: msi-controller@a {
+		reg = <0xa 0x1>;
+		compatible = "vendor,some-controller";
+		msi-controller;
+		#msi-cells = <1>;
+	};
+
+	pci: pci@f {
+		reg = <0xf 0x1>;
+		compatible = "vendor,pcie-root-complex";
+		device_type = "pci";
+
+		/*
+		 * The sideband data provided to the MSI controller is
+		 * the RID, but the high bit of the bus number is
+		 * negated.
+		 */
+		msi-map = <0x0000 &msi 0x8000 0x8000>,
+			  <0x8000 &msi 0x0000 0x8000>;
+	};
+};
+
+
+Example (5)
+===========
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	msi_a: msi-controller@a {
+		reg = <0xa 0x1>;
+		compatible = "vendor,some-controller";
+		msi-controller;
+		#msi-cells = <1>;
+	};
+
+	msi_b: msi-controller@b {
+		reg = <0xb 0x1>;
+		compatible = "vendor,some-controller";
+		msi-controller;
+		#msi-cells = <1>;
+	};
+
+	msi_c: msi-controller@c {
+		reg = <0xc 0x1>;
+		compatible = "vendor,some-controller";
+		msi-controller;
+		#msi-cells = <1>;
+	};
+
+	pci: pci@c {
+		reg = <0xf 0x1>;
+		compatible = "vendor,pcie-root-complex";
+		device_type = "pci";
+
+		/*
+		 * The sideband data provided to MSI controller a is the
+		 * RID, but the high bit of the bus number is negated.
+		 * The sideband data provided to MSI controller b is the
+		 * RID, identity-mapped.
+		 * MSI controller c is not addressable.
+		 */
+		msi-map = <0x0000 &msi_a 0x8000 0x08000>,
+			  <0x8000 &msi_a 0x0000 0x08000>,
+			  <0x0000 &msi_b 0x0000 0x10000>;
+	};
+};

drivers/irqchip/irq-gic-v3-its-pci-msi.c

@@ -42,7 +42,6 @@ static struct irq_chip its_msi_irq_chip = {
 
 struct its_pci_alias {
 	struct pci_dev	*pdev;
-	u32		dev_id;
 	u32		count;
 };
 
@@ -60,7 +59,6 @@ static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
 {
 	struct its_pci_alias *dev_alias = data;
 
-	dev_alias->dev_id = alias;
 	if (pdev != dev_alias->pdev)
 		dev_alias->count += its_pci_msi_vec_count(pdev);
 
@@ -86,7 +84,7 @@ static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
 	pci_for_each_dma_alias(pdev, its_get_pci_alias, &dev_alias);
 
 	/* ITS specific DeviceID, as the core ITS ignores dev. */
-	info->scratchpad[0].ul = dev_alias.dev_id;
+	info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);
 
 	return msi_info->ops->msi_prepare(domain->parent,
 					  dev, dev_alias.count, info);

drivers/irqchip/irq-gic-v3-its-platform-msi.c

@@ -29,13 +29,25 @@ static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
 {
 	struct msi_domain_info *msi_info;
 	u32 dev_id;
-	int ret;
+	int ret, index = 0;
 
 	msi_info = msi_get_domain_info(domain->parent);
 
 	/* Suck the DeviceID out of the msi-parent property */
-	ret = of_property_read_u32_index(dev->of_node, "msi-parent",
-					 1, &dev_id);
+	do {
+		struct of_phandle_args args;
+
+		ret = of_parse_phandle_with_args(dev->of_node,
+						 "msi-parent", "#msi-cells",
+						 index, &args);
+		if (args.np == irq_domain_get_of_node(domain)) {
+			if (WARN_ON(args.args_count != 1))
+				return -EINVAL;
+			dev_id = args.args[0];
+			break;
+		}
+	} while (!ret);
+
 	if (ret)
 		return ret;
 

drivers/of/irq.c

@@ -579,22 +579,187 @@ err:
 	}
 }
 
+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);
+
+		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 + 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;
+}
+
 /**
- * of_msi_configure - Set the msi_domain field of a device
- * @dev: device structure to associate with an MSI irq domain
- * @np: device node for that device
+ * 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.
  */
-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)
+{
+	return __of_msi_map_rid(dev, &msi_np, rid_in);
+}
+
+static struct irq_domain *__of_get_msi_domain(struct device_node *np,
+					      enum irq_domain_bus_token token)
+{
+	struct irq_domain *d;
+
+	d = irq_find_matching_host(np, token);
+	if (!d)
+		d = irq_find_host(np);
+
+	return d;
+}
+
+/**
+ * of_msi_map_get_device_domain - Use msi-map to find the relevant MSI domain
+ * @dev: device for which the mapping is to be done.
+ * @rid: Requester ID for the device.
+ *
+ * Walk up the device hierarchy looking for devices with a "msi-map"
+ * property.
+ *
+ * Returns: the MSI domain for this device (or NULL on failure)
+ */
+struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 rid)
+{
+	struct device_node *np = NULL;
+
+	__of_msi_map_rid(dev, &np, rid);
+	return __of_get_msi_domain(np, DOMAIN_BUS_PCI_MSI);
+}
+
+/**
+ * of_msi_get_domain - Use msi-parent to find the relevant MSI domain
+ * @dev: device for which the domain is requested
+ * @np: device node for @dev
+ * @token: bus type for this domain
+ *
+ * Parse the msi-parent property (both the simple and the complex
+ * versions), and returns the corresponding MSI domain.
+ *
+ * Returns: the MSI domain for this device (or NULL on failure).
+ */
+struct irq_domain *of_msi_get_domain(struct device *dev,
+				     struct device_node *np,
+				     enum irq_domain_bus_token token)
 {
 	struct device_node *msi_np;
 	struct irq_domain *d;
 
+	/* Check for a single msi-parent property */
 	msi_np = of_parse_phandle(np, "msi-parent", 0);
-	if (!msi_np)
-		return;
+	if (msi_np && !of_property_read_bool(msi_np, "#msi-cells")) {
+		d = __of_get_msi_domain(msi_np, token);
+		if (!d)
+			of_node_put(msi_np);
+		return d;
+	}
 
-	d = irq_find_matching_host(msi_np, DOMAIN_BUS_PLATFORM_MSI);
-	if (!d)
-		d = irq_find_host(msi_np);
-	dev_set_msi_domain(dev, d);
+	if (token == DOMAIN_BUS_PLATFORM_MSI) {
+		/* Check for the complex msi-parent version */
+		struct of_phandle_args args;
+		int index = 0;
+
+		while (!of_parse_phandle_with_args(np, "msi-parent",
+						   "#msi-cells",
+						   index, &args)) {
+			d = __of_get_msi_domain(args.np, token);
+			if (d)
+				return d;
+
+			of_node_put(args.np);
+			index++;
+		}
+	}
+
+	return NULL;
+}
+
+/**
+ * of_msi_configure - Set the msi_domain field of a device
+ * @dev: device structure to associate with an MSI irq domain
+ * @np: device node for that device
+ */
+void of_msi_configure(struct device *dev, struct device_node *np)
+{
+	dev_set_msi_domain(dev,
+			   of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
 }

drivers/pci/msi.c

@@ -20,6 +20,7 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/irqdomain.h>
+#include <linux/of_irq.h>
 
 #include "pci.h"
 
@@ -1327,4 +1328,52 @@ struct irq_domain *pci_msi_create_default_irq_domain(struct fwnode_handle *fwnod
 
 	return domain;
 }
+
+static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data)
+{
+	u32 *pa = data;
+
+	*pa = alias;
+	return 0;
+}
+/**
+ * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID)
+ * @domain:	The interrupt domain
+ * @pdev:	The PCI device.
+ *
+ * The RID for a device is formed from the alias, with a firmware
+ * supplied mapping applied
+ *
+ * Returns: The RID.
+ */
+u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
+{
+	struct device_node *of_node;
+	u32 rid = 0;
+
+	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+
+	of_node = irq_domain_get_of_node(domain);
+	if (of_node)
+		rid = of_msi_map_rid(&pdev->dev, of_node, rid);
+
+	return rid;
+}
+
+/**
+ * pci_msi_get_device_domain - Get the MSI domain for a given PCI device
+ * @pdev:	The PCI device
+ *
+ * Use the firmware data to find a device-specific MSI domain
+ * (i.e. not one that is ste as a default).
+ *
+ * Returns: The coresponding MSI domain or NULL if none has been found.
+ */
+struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
+{
+	u32 rid = 0;
+
+	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+	return of_msi_map_get_device_domain(&pdev->dev, rid);
+}
 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */

drivers/pci/of.c

@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/of.h>
+#include <linux/of_irq.h>
 #include <linux/of_pci.h>
 #include "pci.h"
 
@@ -64,27 +65,25 @@ struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
 {
 #ifdef CONFIG_IRQ_DOMAIN
-	struct device_node *np;
 	struct irq_domain *d;
 
 	if (!bus->dev.of_node)
 		return NULL;
 
 	/* Start looking for a phandle to an MSI controller. */
-	np = of_parse_phandle(bus->dev.of_node, "msi-parent", 0);
+	d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
+	if (d)
+		return d;
 
 	/*
 	 * If we don't have an msi-parent property, look for a domain
 	 * directly attached to the host bridge.
 	 */
-	if (!np)
-		np = bus->dev.of_node;
-
-	d = irq_find_matching_host(np, DOMAIN_BUS_PCI_MSI);
+	d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
 	if (d)
 		return d;
 
-	return irq_find_host(np);
+	return irq_find_host(bus->dev.of_node);
 #else
 	return NULL;
 #endif

drivers/pci/probe.c

@@ -1622,15 +1622,48 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_enable_acs(dev);
 }
 
+/*
+ * This is the equivalent of pci_host_bridge_msi_domain that acts on
+ * devices. Firmware interfaces that can select the MSI domain on a
+ * per-device basis should be called from here.
+ */
+static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev)
+{
+	struct irq_domain *d;
+
+	/*
+	 * If a domain has been set through the pcibios_add_device
+	 * callback, then this is the one (platform code knows best).
+	 */
+	d = dev_get_msi_domain(&dev->dev);
+	if (d)
+		return d;
+
+	/*
+	 * Let's see if we have a firmware interface able to provide
+	 * the domain.
+	 */
+	d = pci_msi_get_device_domain(dev);
+	if (d)
+		return d;
+
+	return NULL;
+}
+
 static void pci_set_msi_domain(struct pci_dev *dev)
 {
+	struct irq_domain *d;
+
 	/*
-	 * If no domain has been set through the pcibios_add_device
-	 * callback, inherit the default from the bus device.
+	 * If the platform or firmware interfaces cannot supply a
+	 * device-specific MSI domain, then inherit the default domain
+	 * from the host bridge itself.
 	 */
-	if (!dev_get_msi_domain(&dev->dev))
-		dev_set_msi_domain(&dev->dev,
-				   dev_get_msi_domain(&dev->bus->dev));
+	d = pci_dev_msi_domain(dev);
+	if (!d)
+		d = dev_get_msi_domain(&dev->bus->dev);
+
+	dev_set_msi_domain(&dev->dev, d);
 }
 
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)

include/linux/msi.h

@@ -294,6 +294,13 @@ irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
 					  struct msi_desc *desc);
 int pci_msi_domain_check_cap(struct irq_domain *domain,
 			     struct msi_domain_info *info, struct device *dev);
+u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
+struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
+#else
+static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
+{
+	return NULL;
+}
 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
 
 #endif /* LINUX_MSI_H */

include/linux/of_irq.h

@@ -46,6 +46,11 @@ extern int of_irq_get(struct device_node *dev, int index);
 extern int of_irq_get_byname(struct device_node *dev, const char *name);
 extern int of_irq_to_resource_table(struct device_node *dev,
 		struct resource *res, int nr_irqs);
+extern struct irq_domain *of_msi_get_domain(struct device *dev,
+					    struct device_node *np,
+					    enum irq_domain_bus_token token);
+extern struct irq_domain *of_msi_map_get_device_domain(struct device *dev,
+						       u32 rid);
 #else
 static inline int of_irq_count(struct device_node *dev)
 {
@@ -64,6 +69,17 @@ static inline int of_irq_to_resource_table(struct device_node *dev,
 {
 	return 0;
 }
+static inline struct irq_domain *of_msi_get_domain(struct device *dev,
+						   struct device_node *np,
+						   enum irq_domain_bus_token token)
+{
+	return NULL;
+}
+static inline struct irq_domain *of_msi_map_get_device_domain(struct device *dev,
+							      u32 rid)
+{
+	return NULL;
+}
 #endif
 
 #if defined(CONFIG_OF)
@@ -75,6 +91,7 @@ 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 +104,12 @@ 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 */