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Commit 8db02d8b authored by David Daney's avatar David Daney Committed by Marc Zyngier
Browse files

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: default avatarMarc Zyngier <marc.zyngier@arm.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarDavid Daney <david.daney@cavium.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent b531566e

drivers/of/irq.c

+84 −0
Original line number Diff line number Diff line
@@ -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;

}

include/linux/of_irq.h

+7 −0
Original line number Diff line number Diff line
@@ -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 */