[PATCH v3] of/pci: Provide support for parsing PCI DT ranges property

Andrew Murray Andrew.Murray at arm.com
Tue Apr 9 00:33:20 EST 2013


This patch factors out common implementation patterns to reduce overall kernel
code and provide a means for host bridge drivers to directly obtain struct
resources from the DT's ranges property without relying on architecture specific
DT handling. This will make it easier to write archiecture independent host bridge
drivers and mitigate against further duplication of DT parsing code.

This patch can be used in the following way:

	struct of_pci_range_parser parser;
	struct of_pci_range range;

	if (of_pci_range_parser(&parser, np))
		; //no ranges property

	for_each_of_pci_range(&parser, &range) {

		/*
			directly access properties of the address range, e.g.:
			range.pci_space, range.pci_addr, range.cpu_addr,
			range.size, range.flags

			alternatively obtain a struct resource, e.g.:
			struct resource res;
			of_pci_range_to_resource(&range, np, &res);
		*/
	}

Additionally the implementation takes care of adjacent ranges and merges them
into a single range (as was the case with powerpc and microblaze).

The modifications to microblaze, mips and powerpc have not been tested.

Signed-off-by: Andrew Murray <Andrew.Murray at arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau at arm.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
Compared to the v3 sent by Andrew Murray, the following changes have
been made:

 * Unify and move duplicate pci_process_bridge_OF_ranges functions to
   drivers/of/of_pci.c as suggested by Rob Herring

 * Fix potential build errors with Microblaze/MIPS

Compared to "[PATCH v5 01/17] of/pci: Provide support for parsing PCI DT
ranges property", the following changes have been made:

 * Correct use of IORESOURCE_* as suggested by Russell King

 * Improved interface and naming as suggested by Thierry Reding

Compared to the v2 sent by Andrew Murray, Thomas Petazzoni did:

 * Add a memset() on the struct of_pci_range_iter when starting the
   for loop in for_each_pci_range(). Otherwise, with an uninitialized
   of_pci_range_iter, of_pci_process_ranges() may crash.

 * Add parenthesis around 'res', 'np' and 'iter' in the
   for_each_of_pci_range macro definitions. Otherwise, passing
   something like &foobar as 'res' didn't work.

 * Rebased on top of 3.9-rc2, which required fixing a few conflicts in
   the Microblaze code.

v2:
  This follows on from suggestions made by Grant Likely
  (marc.info/?l=linux-kernel&m=136079602806328)
---
 arch/microblaze/include/asm/pci-bridge.h |    5 +-
 arch/microblaze/pci/pci-common.c         |  192 ------------------------------
 arch/mips/pci/pci.c                      |   50 +++------
 arch/powerpc/include/asm/pci-bridge.h    |    5 +-
 arch/powerpc/kernel/pci-common.c         |  192 ------------------------------
 drivers/of/address.c                     |   63 ++++++++++
 drivers/of/of_pci.c                      |  168 ++++++++++++++++++++++++++
 include/linux/of_address.h               |   42 +++++++
 include/linux/of_pci.h                   |    3 +
 9 files changed, 294 insertions(+), 426 deletions(-)

diff --git a/arch/microblaze/include/asm/pci-bridge.h b/arch/microblaze/include/asm/pci-bridge.h
index cb5d397..5783cd6 100644
--- a/arch/microblaze/include/asm/pci-bridge.h
+++ b/arch/microblaze/include/asm/pci-bridge.h
@@ -10,6 +10,7 @@
 #include <linux/pci.h>
 #include <linux/list.h>
 #include <linux/ioport.h>
+#include <linux/of_pci.h>
 
 struct device_node;
 
@@ -132,10 +133,6 @@ extern void setup_indirect_pci(struct pci_controller *hose,
 extern struct pci_controller *pci_find_hose_for_OF_device(
 			struct device_node *node);
 
-/* Fill up host controller resources from the OF node */
-extern void pci_process_bridge_OF_ranges(struct pci_controller *hose,
-			struct device_node *dev, int primary);
-
 /* Allocate & free a PCI host bridge structure */
 extern struct pci_controller *pcibios_alloc_controller(struct device_node *dev);
 extern void pcibios_free_controller(struct pci_controller *phb);
diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index 9ea521e..2735ad9 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -622,198 +622,6 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar,
 	*end = rsrc->end - offset;
 }
 
-/**
- * pci_process_bridge_OF_ranges - Parse PCI bridge resources from device tree
- * @hose: newly allocated pci_controller to be setup
- * @dev: device node of the host bridge
- * @primary: set if primary bus (32 bits only, soon to be deprecated)
- *
- * This function will parse the "ranges" property of a PCI host bridge device
- * node and setup the resource mapping of a pci controller based on its
- * content.
- *
- * Life would be boring if it wasn't for a few issues that we have to deal
- * with here:
- *
- *   - We can only cope with one IO space range and up to 3 Memory space
- *     ranges. However, some machines (thanks Apple !) tend to split their
- *     space into lots of small contiguous ranges. So we have to coalesce.
- *
- *   - We can only cope with all memory ranges having the same offset
- *     between CPU addresses and PCI addresses. Unfortunately, some bridges
- *     are setup for a large 1:1 mapping along with a small "window" which
- *     maps PCI address 0 to some arbitrary high address of the CPU space in
- *     order to give access to the ISA memory hole.
- *     The way out of here that I've chosen for now is to always set the
- *     offset based on the first resource found, then override it if we
- *     have a different offset and the previous was set by an ISA hole.
- *
- *   - Some busses have IO space not starting at 0, which causes trouble with
- *     the way we do our IO resource renumbering. The code somewhat deals with
- *     it for 64 bits but I would expect problems on 32 bits.
- *
- *   - Some 32 bits platforms such as 4xx can have physical space larger than
- *     32 bits so we need to use 64 bits values for the parsing
- */
-void pci_process_bridge_OF_ranges(struct pci_controller *hose,
-				  struct device_node *dev, int primary)
-{
-	const u32 *ranges;
-	int rlen;
-	int pna = of_n_addr_cells(dev);
-	int np = pna + 5;
-	int memno = 0, isa_hole = -1;
-	u32 pci_space;
-	unsigned long long pci_addr, cpu_addr, pci_next, cpu_next, size;
-	unsigned long long isa_mb = 0;
-	struct resource *res;
-
-	pr_info("PCI host bridge %s %s ranges:\n",
-	       dev->full_name, primary ? "(primary)" : "");
-
-	/* Get ranges property */
-	ranges = of_get_property(dev, "ranges", &rlen);
-	if (ranges == NULL)
-		return;
-
-	/* Parse it */
-	pr_debug("Parsing ranges property...\n");
-	while ((rlen -= np * 4) >= 0) {
-		/* Read next ranges element */
-		pci_space = ranges[0];
-		pci_addr = of_read_number(ranges + 1, 2);
-		cpu_addr = of_translate_address(dev, ranges + 3);
-		size = of_read_number(ranges + pna + 3, 2);
-
-		pr_debug("pci_space: 0x%08x pci_addr:0x%016llx ",
-				pci_space, pci_addr);
-		pr_debug("cpu_addr:0x%016llx size:0x%016llx\n",
-					cpu_addr, size);
-
-		ranges += np;
-
-		/* If we failed translation or got a zero-sized region
-		 * (some FW try to feed us with non sensical zero sized regions
-		 * such as power3 which look like some kind of attempt
-		 * at exposing the VGA memory hole)
-		 */
-		if (cpu_addr == OF_BAD_ADDR || size == 0)
-			continue;
-
-		/* Now consume following elements while they are contiguous */
-		for (; rlen >= np * sizeof(u32);
-		     ranges += np, rlen -= np * 4) {
-			if (ranges[0] != pci_space)
-				break;
-			pci_next = of_read_number(ranges + 1, 2);
-			cpu_next = of_translate_address(dev, ranges + 3);
-			if (pci_next != pci_addr + size ||
-			    cpu_next != cpu_addr + size)
-				break;
-			size += of_read_number(ranges + pna + 3, 2);
-		}
-
-		/* Act based on address space type */
-		res = NULL;
-		switch ((pci_space >> 24) & 0x3) {
-		case 1:		/* PCI IO space */
-			pr_info("  IO 0x%016llx..0x%016llx -> 0x%016llx\n",
-			       cpu_addr, cpu_addr + size - 1, pci_addr);
-
-			/* We support only one IO range */
-			if (hose->pci_io_size) {
-				pr_info(" \\--> Skipped (too many) !\n");
-				continue;
-			}
-			/* On 32 bits, limit I/O space to 16MB */
-			if (size > 0x01000000)
-				size = 0x01000000;
-
-			/* 32 bits needs to map IOs here */
-			hose->io_base_virt = ioremap(cpu_addr, size);
-
-			/* Expect trouble if pci_addr is not 0 */
-			if (primary)
-				isa_io_base =
-					(unsigned long)hose->io_base_virt;
-			/* pci_io_size and io_base_phys always represent IO
-			 * space starting at 0 so we factor in pci_addr
-			 */
-			hose->pci_io_size = pci_addr + size;
-			hose->io_base_phys = cpu_addr - pci_addr;
-
-			/* Build resource */
-			res = &hose->io_resource;
-			res->flags = IORESOURCE_IO;
-			res->start = pci_addr;
-			break;
-		case 2:		/* PCI Memory space */
-		case 3:		/* PCI 64 bits Memory space */
-			pr_info(" MEM 0x%016llx..0x%016llx -> 0x%016llx %s\n",
-			       cpu_addr, cpu_addr + size - 1, pci_addr,
-			       (pci_space & 0x40000000) ? "Prefetch" : "");
-
-			/* We support only 3 memory ranges */
-			if (memno >= 3) {
-				pr_info(" \\--> Skipped (too many) !\n");
-				continue;
-			}
-			/* Handles ISA memory hole space here */
-			if (pci_addr == 0) {
-				isa_mb = cpu_addr;
-				isa_hole = memno;
-				if (primary || isa_mem_base == 0)
-					isa_mem_base = cpu_addr;
-				hose->isa_mem_phys = cpu_addr;
-				hose->isa_mem_size = size;
-			}
-
-			/* We get the PCI/Mem offset from the first range or
-			 * the, current one if the offset came from an ISA
-			 * hole. If they don't match, bugger.
-			 */
-			if (memno == 0 ||
-			    (isa_hole >= 0 && pci_addr != 0 &&
-			     hose->pci_mem_offset == isa_mb))
-				hose->pci_mem_offset = cpu_addr - pci_addr;
-			else if (pci_addr != 0 &&
-				 hose->pci_mem_offset != cpu_addr - pci_addr) {
-				pr_info(" \\--> Skipped (offset mismatch) !\n");
-				continue;
-			}
-
-			/* Build resource */
-			res = &hose->mem_resources[memno++];
-			res->flags = IORESOURCE_MEM;
-			if (pci_space & 0x40000000)
-				res->flags |= IORESOURCE_PREFETCH;
-			res->start = cpu_addr;
-			break;
-		}
-		if (res != NULL) {
-			res->name = dev->full_name;
-			res->end = res->start + size - 1;
-			res->parent = NULL;
-			res->sibling = NULL;
-			res->child = NULL;
-		}
-	}
-
-	/* If there's an ISA hole and the pci_mem_offset is -not- matching
-	 * the ISA hole offset, then we need to remove the ISA hole from
-	 * the resource list for that brige
-	 */
-	if (isa_hole >= 0 && hose->pci_mem_offset != isa_mb) {
-		unsigned int next = isa_hole + 1;
-		pr_info(" Removing ISA hole at 0x%016llx\n", isa_mb);
-		if (next < memno)
-			memmove(&hose->mem_resources[isa_hole],
-				&hose->mem_resources[next],
-				sizeof(struct resource) * (memno - next));
-		hose->mem_resources[--memno].flags = 0;
-	}
-}
-
 /* Decide whether to display the domain number in /proc */
 int pci_proc_domain(struct pci_bus *bus)
 {
diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
index 0872f12..bee49a4 100644
--- a/arch/mips/pci/pci.c
+++ b/arch/mips/pci/pci.c
@@ -122,51 +122,33 @@ static void pcibios_scanbus(struct pci_controller *hose)
 #ifdef CONFIG_OF
 void pci_load_of_ranges(struct pci_controller *hose, struct device_node *node)
 {
-	const __be32 *ranges;
-	int rlen;
-	int pna = of_n_addr_cells(node);
-	int np = pna + 5;
+	struct of_pci_range_range range;
+	struct of_pci_range_parser parser;
+	u32 res_type;
 
 	pr_info("PCI host bridge %s ranges:\n", node->full_name);
-	ranges = of_get_property(node, "ranges", &rlen);
-	if (ranges == NULL)
-		return;
 	hose->of_node = node;
 
-	while ((rlen -= np * 4) >= 0) {
-		u32 pci_space;
+	if (of_pci_range_parser(&parser, node))
+		return;
+
+	for_each_of_pci_range(&parser, &range) {
 		struct resource *res = NULL;
-		u64 addr, size;
-
-		pci_space = be32_to_cpup(&ranges[0]);
-		addr = of_translate_address(node, ranges + 3);
-		size = of_read_number(ranges + pna + 3, 2);
-		ranges += np;
-		switch ((pci_space >> 24) & 0x3) {
-		case 1:		/* PCI IO space */
+
+		res_type = range.flags & IORESOURCE_TYPE_BITS;
+		if (res_type == IORESOURCE_IO) {
 			pr_info("  IO 0x%016llx..0x%016llx\n",
-					addr, addr + size - 1);
+				range.addr, range.addr + range.size - 1);
 			hose->io_map_base =
-				(unsigned long)ioremap(addr, size);
+				(unsigned long)ioremap(range.addr, range.size);
 			res = hose->io_resource;
-			res->flags = IORESOURCE_IO;
-			break;
-		case 2:		/* PCI Memory space */
-		case 3:		/* PCI 64 bits Memory space */
+		} else if (res_type == IORESOURCE_MEM) {
 			pr_info(" MEM 0x%016llx..0x%016llx\n",
-					addr, addr + size - 1);
+				range.addr, range.addr + range.size - 1);
 			res = hose->mem_resource;
-			res->flags = IORESOURCE_MEM;
-			break;
-		}
-		if (res != NULL) {
-			res->start = addr;
-			res->name = node->full_name;
-			res->end = res->start + size - 1;
-			res->parent = NULL;
-			res->sibling = NULL;
-			res->child = NULL;
 		}
+		if (res != NULL)
+			of_pci_range_to_resource(&range, node, res);
 	}
 }
 #endif
diff --git a/arch/powerpc/include/asm/pci-bridge.h b/arch/powerpc/include/asm/pci-bridge.h
index 025a130..205bfba 100644
--- a/arch/powerpc/include/asm/pci-bridge.h
+++ b/arch/powerpc/include/asm/pci-bridge.h
@@ -10,6 +10,7 @@
 #include <linux/pci.h>
 #include <linux/list.h>
 #include <linux/ioport.h>
+#include <linux/of_pci.h>
 #include <asm-generic/pci-bridge.h>
 
 struct device_node;
@@ -231,10 +232,6 @@ extern int pcibios_map_io_space(struct pci_bus *bus);
 extern struct pci_controller *pci_find_hose_for_OF_device(
 			struct device_node* node);
 
-/* Fill up host controller resources from the OF node */
-extern void pci_process_bridge_OF_ranges(struct pci_controller *hose,
-			struct device_node *dev, int primary);
-
 /* Allocate & free a PCI host bridge structure */
 extern struct pci_controller *pcibios_alloc_controller(struct device_node *dev);
 extern void pcibios_free_controller(struct pci_controller *phb);
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index fa12ae4..6edf396 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -640,198 +640,6 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar,
 	*end = rsrc->end - offset;
 }
 
-/**
- * pci_process_bridge_OF_ranges - Parse PCI bridge resources from device tree
- * @hose: newly allocated pci_controller to be setup
- * @dev: device node of the host bridge
- * @primary: set if primary bus (32 bits only, soon to be deprecated)
- *
- * This function will parse the "ranges" property of a PCI host bridge device
- * node and setup the resource mapping of a pci controller based on its
- * content.
- *
- * Life would be boring if it wasn't for a few issues that we have to deal
- * with here:
- *
- *   - We can only cope with one IO space range and up to 3 Memory space
- *     ranges. However, some machines (thanks Apple !) tend to split their
- *     space into lots of small contiguous ranges. So we have to coalesce.
- *
- *   - We can only cope with all memory ranges having the same offset
- *     between CPU addresses and PCI addresses. Unfortunately, some bridges
- *     are setup for a large 1:1 mapping along with a small "window" which
- *     maps PCI address 0 to some arbitrary high address of the CPU space in
- *     order to give access to the ISA memory hole.
- *     The way out of here that I've chosen for now is to always set the
- *     offset based on the first resource found, then override it if we
- *     have a different offset and the previous was set by an ISA hole.
- *
- *   - Some busses have IO space not starting at 0, which causes trouble with
- *     the way we do our IO resource renumbering. The code somewhat deals with
- *     it for 64 bits but I would expect problems on 32 bits.
- *
- *   - Some 32 bits platforms such as 4xx can have physical space larger than
- *     32 bits so we need to use 64 bits values for the parsing
- */
-void pci_process_bridge_OF_ranges(struct pci_controller *hose,
-				  struct device_node *dev, int primary)
-{
-	const u32 *ranges;
-	int rlen;
-	int pna = of_n_addr_cells(dev);
-	int np = pna + 5;
-	int memno = 0, isa_hole = -1;
-	u32 pci_space;
-	unsigned long long pci_addr, cpu_addr, pci_next, cpu_next, size;
-	unsigned long long isa_mb = 0;
-	struct resource *res;
-
-	printk(KERN_INFO "PCI host bridge %s %s ranges:\n",
-	       dev->full_name, primary ? "(primary)" : "");
-
-	/* Get ranges property */
-	ranges = of_get_property(dev, "ranges", &rlen);
-	if (ranges == NULL)
-		return;
-
-	/* Parse it */
-	while ((rlen -= np * 4) >= 0) {
-		/* Read next ranges element */
-		pci_space = ranges[0];
-		pci_addr = of_read_number(ranges + 1, 2);
-		cpu_addr = of_translate_address(dev, ranges + 3);
-		size = of_read_number(ranges + pna + 3, 2);
-		ranges += np;
-
-		/* If we failed translation or got a zero-sized region
-		 * (some FW try to feed us with non sensical zero sized regions
-		 * such as power3 which look like some kind of attempt at exposing
-		 * the VGA memory hole)
-		 */
-		if (cpu_addr == OF_BAD_ADDR || size == 0)
-			continue;
-
-		/* Now consume following elements while they are contiguous */
-		for (; rlen >= np * sizeof(u32);
-		     ranges += np, rlen -= np * 4) {
-			if (ranges[0] != pci_space)
-				break;
-			pci_next = of_read_number(ranges + 1, 2);
-			cpu_next = of_translate_address(dev, ranges + 3);
-			if (pci_next != pci_addr + size ||
-			    cpu_next != cpu_addr + size)
-				break;
-			size += of_read_number(ranges + pna + 3, 2);
-		}
-
-		/* Act based on address space type */
-		res = NULL;
-		switch ((pci_space >> 24) & 0x3) {
-		case 1:		/* PCI IO space */
-			printk(KERN_INFO
-			       "  IO 0x%016llx..0x%016llx -> 0x%016llx\n",
-			       cpu_addr, cpu_addr + size - 1, pci_addr);
-
-			/* We support only one IO range */
-			if (hose->pci_io_size) {
-				printk(KERN_INFO
-				       " \\--> Skipped (too many) !\n");
-				continue;
-			}
-#ifdef CONFIG_PPC32
-			/* On 32 bits, limit I/O space to 16MB */
-			if (size > 0x01000000)
-				size = 0x01000000;
-
-			/* 32 bits needs to map IOs here */
-			hose->io_base_virt = ioremap(cpu_addr, size);
-
-			/* Expect trouble if pci_addr is not 0 */
-			if (primary)
-				isa_io_base =
-					(unsigned long)hose->io_base_virt;
-#endif /* CONFIG_PPC32 */
-			/* pci_io_size and io_base_phys always represent IO
-			 * space starting at 0 so we factor in pci_addr
-			 */
-			hose->pci_io_size = pci_addr + size;
-			hose->io_base_phys = cpu_addr - pci_addr;
-
-			/* Build resource */
-			res = &hose->io_resource;
-			res->flags = IORESOURCE_IO;
-			res->start = pci_addr;
-			break;
-		case 2:		/* PCI Memory space */
-		case 3:		/* PCI 64 bits Memory space */
-			printk(KERN_INFO
-			       " MEM 0x%016llx..0x%016llx -> 0x%016llx %s\n",
-			       cpu_addr, cpu_addr + size - 1, pci_addr,
-			       (pci_space & 0x40000000) ? "Prefetch" : "");
-
-			/* We support only 3 memory ranges */
-			if (memno >= 3) {
-				printk(KERN_INFO
-				       " \\--> Skipped (too many) !\n");
-				continue;
-			}
-			/* Handles ISA memory hole space here */
-			if (pci_addr == 0) {
-				isa_mb = cpu_addr;
-				isa_hole = memno;
-				if (primary || isa_mem_base == 0)
-					isa_mem_base = cpu_addr;
-				hose->isa_mem_phys = cpu_addr;
-				hose->isa_mem_size = size;
-			}
-
-			/* We get the PCI/Mem offset from the first range or
-			 * the, current one if the offset came from an ISA
-			 * hole. If they don't match, bugger.
-			 */
-			if (memno == 0 ||
-			    (isa_hole >= 0 && pci_addr != 0 &&
-			     hose->pci_mem_offset == isa_mb))
-				hose->pci_mem_offset = cpu_addr - pci_addr;
-			else if (pci_addr != 0 &&
-				 hose->pci_mem_offset != cpu_addr - pci_addr) {
-				printk(KERN_INFO
-				       " \\--> Skipped (offset mismatch) !\n");
-				continue;
-			}
-
-			/* Build resource */
-			res = &hose->mem_resources[memno++];
-			res->flags = IORESOURCE_MEM;
-			if (pci_space & 0x40000000)
-				res->flags |= IORESOURCE_PREFETCH;
-			res->start = cpu_addr;
-			break;
-		}
-		if (res != NULL) {
-			res->name = dev->full_name;
-			res->end = res->start + size - 1;
-			res->parent = NULL;
-			res->sibling = NULL;
-			res->child = NULL;
-		}
-	}
-
-	/* If there's an ISA hole and the pci_mem_offset is -not- matching
-	 * the ISA hole offset, then we need to remove the ISA hole from
-	 * the resource list for that brige
-	 */
-	if (isa_hole >= 0 && hose->pci_mem_offset != isa_mb) {
-		unsigned int next = isa_hole + 1;
-		printk(KERN_INFO " Removing ISA hole at 0x%016llx\n", isa_mb);
-		if (next < memno)
-			memmove(&hose->mem_resources[isa_hole],
-				&hose->mem_resources[next],
-				sizeof(struct resource) * (memno - next));
-		hose->mem_resources[--memno].flags = 0;
-	}
-}
-
 /* Decide whether to display the domain number in /proc */
 int pci_proc_domain(struct pci_bus *bus)
 {
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 04da786..e87f45e 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -227,6 +227,69 @@ int of_pci_address_to_resource(struct device_node *dev, int bar,
 	return __of_address_to_resource(dev, addrp, size, flags, NULL, r);
 }
 EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
+
+int of_pci_range_parser(struct of_pci_range_parser *parser,
+			struct device_node *node)
+{
+	const int na = 3, ns = 2;
+	int rlen;
+
+	parser->node = node;
+	parser->pna = of_n_addr_cells(node);
+	parser->np = parser->pna + na + ns;
+
+	parser->range = of_get_property(node, "ranges", &rlen);
+	if (parser->range == NULL)
+		return -ENOENT;
+
+	parser->end = parser->range + rlen / sizeof(__be32);
+
+	return 0;
+}
+
+struct of_pci_range *of_pci_process_ranges(struct of_pci_range_parser *parser,
+						struct of_pci_range *range)
+{
+	const int na = 3, ns = 2;
+
+	if (!parser->range || parser->range + parser->np > parser->end)
+		return NULL;
+
+	range->pci_space = be32_to_cpup(parser->range);
+	range->flags = of_bus_pci_get_flags(parser->range);
+	range->pci_addr = of_read_number(parser->range + 1, ns);
+	range->cpu_addr = of_translate_address(parser->node,
+				parser->range + na);
+	range->size = of_read_number(parser->range + parser->pna + na, ns);
+
+	parser->range += parser->np;
+
+	/* Now consume following elements while they are contiguous */
+	while (parser->range + parser->np <= parser->end) {
+		u32 flags, pci_space;
+		u64 pci_addr, cpu_addr, size;
+
+		pci_space = be32_to_cpup(parser->range);
+		flags = of_bus_pci_get_flags(parser->range);
+		pci_addr = of_read_number(parser->range + 1, ns);
+		cpu_addr = of_translate_address(parser->node,
+				parser->range + na);
+		size = of_read_number(parser->range + parser->pna + na, ns);
+
+		if (flags != range->flags)
+			break;
+		if (pci_addr != range->pci_addr + range->size ||
+		    cpu_addr != range->cpu_addr + range->size)
+			break;
+
+		range->size += size;
+		parser->range += parser->np;
+	}
+
+	return range;
+}
+EXPORT_SYMBOL_GPL(of_pci_process_ranges);
+
 #endif /* CONFIG_PCI */
 
 /*
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 13e37e2..f88bd18 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -4,6 +4,10 @@
 #include <linux/of_pci.h>
 #include <asm/prom.h>
 
+#if defined(CONFIG_PPC32) || defined(CONFIG_PPC64) || defined(CONFIG_MICROBLAZE)
+#include <asm/pci-bridge.h>
+#endif
+
 static inline int __of_pci_pci_compare(struct device_node *node,
 				       unsigned int devfn)
 {
@@ -40,3 +44,167 @@ struct device_node *of_pci_find_child_device(struct device_node *parent,
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
+
+/**
+ * pci_process_bridge_OF_ranges - Parse PCI bridge resources from device tree
+ * @hose: newly allocated pci_controller to be setup
+ * @dev: device node of the host bridge
+ * @primary: set if primary bus (32 bits only, soon to be deprecated)
+ *
+ * This function will parse the "ranges" property of a PCI host bridge device
+ * node and setup the resource mapping of a pci controller based on its
+ * content.
+ *
+ * Life would be boring if it wasn't for a few issues that we have to deal
+ * with here:
+ *
+ *   - We can only cope with one IO space range and up to 3 Memory space
+ *     ranges. However, some machines (thanks Apple !) tend to split their
+ *     space into lots of small contiguous ranges. So we have to coalesce.
+ *
+ *   - We can only cope with all memory ranges having the same offset
+ *     between CPU addresses and PCI addresses. Unfortunately, some bridges
+ *     are setup for a large 1:1 mapping along with a small "window" which
+ *     maps PCI address 0 to some arbitrary high address of the CPU space in
+ *     order to give access to the ISA memory hole.
+ *     The way out of here that I've chosen for now is to always set the
+ *     offset based on the first resource found, then override it if we
+ *     have a different offset and the previous was set by an ISA hole.
+ *
+ *   - Some busses have IO space not starting at 0, which causes trouble with
+ *     the way we do our IO resource renumbering. The code somewhat deals with
+ *     it for 64 bits but I would expect problems on 32 bits.
+ *
+ *   - Some 32 bits platforms such as 4xx can have physical space larger than
+ *     32 bits so we need to use 64 bits values for the parsing
+ */
+#if defined(CONFIG_PPC32) || defined(CONFIG_PPC64) || defined(CONFIG_MICROBLAZE)
+void pci_process_bridge_OF_ranges(struct pci_controller *hose,
+				  struct device_node *dev, int primary)
+{
+	int memno = 0, isa_hole = -1;
+	unsigned long long isa_mb = 0;
+	struct resource *res;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	u32 res_type;
+
+	pr_info("PCI host bridge %s %s ranges:\n",
+	       dev->full_name, primary ? "(primary)" : "");
+
+	/* Check for ranges property */
+	if (of_pci_range_parser(&parser, dev))
+		return;
+
+	pr_debug("Parsing ranges property...\n");
+	for_each_of_pci_range(&parser, &range) {
+		/* Read next ranges element */
+		pr_debug("pci_space: 0x%08x pci_addr: 0x%016llx ",
+				range.pci_space, range.pci_addr);
+		pr_debug("cpu_addr: 0x%016llx size: 0x%016llx\n",
+				range.cpu_addr, range.size);
+
+		/* If we failed translation or got a zero-sized region
+		 * (some FW try to feed us with non sensical zero sized regions
+		 * such as power3 which look like some kind of attempt at
+		 * exposing the VGA memory hole)
+		 */
+		if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
+			continue;
+
+		/* Act based on address space type */
+		res = NULL;
+		res_type = range.flags & IORESOURCE_TYPE_BITS;
+		if (res_type == IORESOURCE_IO) {
+			pr_info("  IO 0x%016llx..0x%016llx -> 0x%016llx\n",
+				range.cpu_addr, range.cpu_addr + range.size - 1,
+				range.pci_addr);
+
+			/* We support only one IO range */
+			if (hose->pci_io_size) {
+				pr_info(" \\--> Skipped (too many) !\n");
+				continue;
+			}
+#if defined(CONFIG_PPC32) || defined(CONFIG_MICROBLAZE)
+			/* On 32 bits, limit I/O space to 16MB */
+			if (range.size > 0x01000000)
+				range.size = 0x01000000;
+
+			/* 32 bits needs to map IOs here */
+			hose->io_base_virt = ioremap(range.cpu_addr,
+						range.size);
+
+			/* Expect trouble if pci_addr is not 0 */
+			if (primary)
+				isa_io_base =
+					(unsigned long)hose->io_base_virt;
+#endif /* CONFIG_PPC32 || CONFIG_MICROBLAZE */
+			/* pci_io_size and io_base_phys always represent IO
+			 * space starting at 0 so we factor in pci_addr
+			 */
+			hose->pci_io_size = range.pci_addr + range.size;
+			hose->io_base_phys = range.cpu_addr - range.pci_addr;
+
+			/* Build resource */
+			res = &hose->io_resource;
+			range.cpu_addr = range.pci_addr;
+		} else if (res_type == IORESOURCE_MEM) {
+			pr_info(" MEM 0x%016llx..0x%016llx -> 0x%016llx %s\n",
+				range.cpu_addr, range.cpu_addr + range.size - 1,
+				range.pci_addr,
+				(range.pci_space & 0x40000000) ?
+				"Prefetch" : "");
+
+			/* We support only 3 memory ranges */
+			if (memno >= 3) {
+				pr_info(" \\--> Skipped (too many) !\n");
+				continue;
+			}
+			/* Handles ISA memory hole space here */
+			if (range.pci_addr == 0) {
+				isa_mb = range.cpu_addr;
+				isa_hole = memno;
+				if (primary || isa_mem_base == 0)
+					isa_mem_base = range.cpu_addr;
+				hose->isa_mem_phys = range.cpu_addr;
+				hose->isa_mem_size = range.size;
+			}
+
+			/* We get the PCI/Mem offset from the first range or
+			 * the, current one if the offset came from an ISA
+			 * hole. If they don't match, bugger.
+			 */
+			if (memno == 0 ||
+			(isa_hole >= 0 && range.pci_addr != 0 &&
+			     hose->pci_mem_offset == isa_mb))
+				hose->pci_mem_offset = range.cpu_addr -
+							range.pci_addr;
+			else if (range.pci_addr != 0 &&
+				hose->pci_mem_offset != range.cpu_addr -
+							range.pci_addr) {
+				pr_info(" \\--> Skipped (offset mismatch) !\n");
+				continue;
+			}
+
+			/* Build resource */
+			res = &hose->mem_resources[memno++];
+		}
+		if (res != NULL)
+			of_pci_range_to_resource(&range, dev, res);
+	}
+
+	/* If there's an ISA hole and the pci_mem_offset is -not- matching
+	 * the ISA hole offset, then we need to remove the ISA hole from
+	 * the resource list for that brige
+	 */
+	if (isa_hole >= 0 && hose->pci_mem_offset != isa_mb) {
+		unsigned int next = isa_hole + 1;
+		pr_info(" Removing ISA hole at 0x%016llx\n", isa_mb);
+		if (next < memno)
+			memmove(&hose->mem_resources[isa_hole],
+				&hose->mem_resources[next],
+				sizeof(struct resource) * (memno - next));
+		hose->mem_resources[--memno].flags = 0;
+	}
+}
+#endif
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 0506eb5..c7003a3 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -4,6 +4,32 @@
 #include <linux/errno.h>
 #include <linux/of.h>
 
+struct of_pci_range_parser {
+	struct device_node *node;
+	const __be32 *range, *end;
+	int np, pna;
+};
+
+struct of_pci_range {
+	u32 pci_space;
+	u64 pci_addr;
+	u64 cpu_addr;
+	u64 size;
+	u32 flags;
+};
+
+#define for_each_of_pci_range(parser, range) \
+	for (; of_pci_process_ranges(parser, range);)
+
+#define of_pci_range_to_resource(range, np, res) \
+	do { \
+		(res)->flags = (range)->flags; \
+		(res)->start = (range)->cpu_addr; \
+		(res)->end = (range)->cpu_addr + (range)->size - 1; \
+		(res)->parent = (res)->child = (res)->sibling = NULL; \
+		(res)->name = (np)->full_name; \
+	} while (0)
+
 #ifdef CONFIG_OF_ADDRESS
 extern u64 of_translate_address(struct device_node *np, const __be32 *addr);
 extern bool of_can_translate_address(struct device_node *dev);
@@ -27,6 +53,10 @@ static inline unsigned long pci_address_to_pio(phys_addr_t addr) { return -1; }
 #define pci_address_to_pio pci_address_to_pio
 #endif
 
+int of_pci_range_parser(struct of_pci_range_parser *parser,
+			struct device_node *node);
+struct of_pci_range *of_pci_process_ranges(struct of_pci_range_parser *parser,
+						struct of_pci_range *range);
 #else /* CONFIG_OF_ADDRESS */
 #ifndef of_address_to_resource
 static inline int of_address_to_resource(struct device_node *dev, int index,
@@ -53,6 +83,18 @@ static inline const __be32 *of_get_address(struct device_node *dev, int index,
 {
 	return NULL;
 }
+
+int of_pci_range_parser(struct of_pci_range_parser *parser,
+			struct device_noed *node)
+{
+	return -1;
+}
+
+struct of_pci_range *of_pci_process_ranges(struct of_pci_range_parser *parser,
+						struct of_pci_range *range)
+{
+	return NULL;
+}
 #endif /* CONFIG_OF_ADDRESS */
 
 
diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index bb115de..6852481 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -11,4 +11,7 @@ struct device_node;
 struct device_node *of_pci_find_child_device(struct device_node *parent,
 					     unsigned int devfn);
 
+void pci_process_bridge_OF_ranges(struct pci_controller *hose,
+			struct device_node *dev, int primary);
+
 #endif
-- 
1.7.0.4



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