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Commit 987068fc authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
Browse files

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: default avatarRob Herring <robh+dt@kernel.org>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Tested-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 6ec2392c

drivers/of/irq.c

+4 −74
Original line number Diff line number Diff line
@@ -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;

}

drivers/of/of_pci.c

+102 −0
Original line number Diff line number Diff line
@@ -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;

}

include/linux/of_pci.h

+10 −0
Original line number Diff line number Diff line
@@ -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