[PATCH v9 0/3] of/pci: Provide common support for PCI DT parsing

[PATCH v9 0/3] of/pci: Provide common support for PCI DT parsing

[Andrew Murray]

This patchset factors out duplicated code associated with parsing PCI
DT "ranges" properties across the architectures and introduces a
"ranges" parser. This parser "of_pci_range_parser" can be used directly
by ARM host bridge drivers enabling them to obtain ranges from device
trees.

I've included the Reviewed-by, Tested-by and Acked-by's received from
v5/v6/v7/v8 in this patchset, earlier versions of this patchset (v3) have been
tested-by:

Thierry Reding <thierry.reding@avionic-design.de>
Jingoo Han <jg1.han@samsung.com>

I've tested that this patchset builds and runs on ARM and that it builds on
PowerPC, x86_64, MIPS and Microblaze.

Compared to the v8 sent by Andrew Murray, the following changes have been made
(please note that the MIPS patch is unchanged from v8):

 * Remove the unification of pci_process_bridge_OF_ranges between PowerPC and
   Microblaze. Feedback from Bjorn and Benjamin (along with a NAK) suggested
   that this goes against their future direction (using more of struct
   pci_host_bridge and less of arch specific struct pci_controller).

Compared to the v7 sent by Andrew Murray, the following changes have been made
(please note that the first patch is unchanged from v7):

 * Rename of_pci_range_parser to of_pci_range_parser_init and
   of_pci_process_ranges to of_pci_range_parser_one as suggested by Grant
   Likely.

 * Reverted back to using a switch statement instead of if/else in
   pci_process_bridge_OF_ranges. Grant Likely highlighted this change from
   the original code which was unnecessary.

 * Squashed in a patch provided by Gabor Juhos which fixes build errors on
   MIPS found in the last patchset.

Compared to the v6 sent by Andrew Murray, the following changes have
been made in response to build errors/warnings:

 * Inclusion of linux/of_address.h in of_pci.c as suggested by Michal
   Simek to prevent compilation failures on Microblaze (and others) and his
   ack.

 * Use of externs, static inlines and a typo in linux/of_address.h in response
   to linker errors (multiple defination) on x86_64 as spotted by a kbuild test
   robot on (jcooper/linux.git mvebu/drivers)

 * Add EXPORT_SYMBOL_GPL to of_pci_range_parser function to be consistent
   with of_pci_process_ranges function

Compared to the v5 sent by Andrew Murray, the following changes have
been made:

 * Use of CONFIG_64BIT instead of CONFIG_[a32bitarch] as suggested by
   Rob Herring in drivers/of/of_pci.c

 * Added forward declaration of struct pci_controller in linux/of_pci.h
   to prevent compiler warning as suggested by Thomas Petazzoni

 * Improved error checking (!range check), removal of unnecessary be32_to_cpup
   call, improved formatting of struct of_pci_range_parser layout and
   replacement of macro with a static inline. All suggested by Rob Herring.

Compared to the v4 (incorrectly labelled v3) sent by Andrew Murray,
the following changes have been made:

 * Split the patch as suggested by Rob Herring

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)

Andrew Murray (3):
  of/pci: Provide support for parsing PCI DT ranges property
  of/pci: mips: convert to common of_pci_range_parser
  of/pci: microblaze: convert to common of_pci_range_parser

 arch/microblaze/pci/pci-common.c |  106 ++++++++++++++------------------------
 arch/mips/pci/pci.c              |   50 ++++++-----------
 drivers/of/address.c             |   67 ++++++++++++++++++++++++
 include/linux/of_address.h       |   48 +++++++++++++++++
 4 files changed, 171 insertions(+), 100 deletions(-)

[PATCH v9 1/3] of/pci: Provide support for parsing PCI DT ranges property

[Andrew Murray]

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_init(&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).

Signed-off-by: Andrew Murray <Andrew.Murray@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
---
 drivers/of/address.c       |   67 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of_address.h |   48 +++++++++++++++++++++++++++++++
 2 files changed, 115 insertions(+), 0 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 04da786..fdd0636 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -227,6 +227,73 @@ 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_init(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;
+}
+EXPORT_SYMBOL_GPL(of_pci_range_parser_init);
+
+struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
+						struct of_pci_range *range)
+{
+	const int na = 3, ns = 2;
+
+	if (!range)
+		return NULL;
+
+	if (!parser->range || parser->range + parser->np > parser->end)
+		return NULL;
+
+	range->pci_space = parser->range[0];
+	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_range_parser_one);
+
 #endif /* CONFIG_PCI */
 
 /*
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 0506eb5..4c2e6f2 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -4,6 +4,36 @@
 #include <linux/errno.h>
 #include <linux/of.h>
 
+struct of_pci_range_parser {
+	struct device_node *node;
+	const __be32 *range;
+	const __be32 *end;
+	int np;
+	int 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_range_parser_one(parser, range);)
+
+static inline void of_pci_range_to_resource(struct of_pci_range *range,
+					    struct device_node *np,
+					    struct resource *res)
+{
+	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;
+}
+
 #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 +57,11 @@ static inline unsigned long pci_address_to_pio(phys_addr_t addr) { return -1; }
 #define pci_address_to_pio pci_address_to_pio
 #endif
 
+extern int of_pci_range_parser_init(struct of_pci_range_parser *parser,
+			struct device_node *node);
+extern struct of_pci_range *of_pci_range_parser_one(
+					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 +88,19 @@ static inline const __be32 *of_get_address(struct device_node *dev, int index,
 {
 	return NULL;
 }
+
+static inline int of_pci_range_parser_init(struct of_pci_range_parser *parser,
+			struct device_node *node)
+{
+	return -1;
+}
+
+static inline struct of_pci_range *of_pci_range_parser_one(
+					struct of_pci_range_parser *parser,
+					struct of_pci_range *range)
+{
+	return NULL;
+}
 #endif /* CONFIG_OF_ADDRESS */
 
 
-- 
1.7.0.4

[PATCH v9 2/3] of/pci: mips: convert to common of_pci_range_parser

[Andrew Murray]

This patch converts the pci_load_of_ranges function to use the new common
of_pci_range_parser.

Signed-off-by: Andrew Murray <Andrew.Murray@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
---
 arch/mips/pci/pci.c |   50 ++++++++++++++++++--------------------------------
 1 files changed, 18 insertions(+), 32 deletions(-)

diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
index 0872f12..0d291e9 100644
--- a/arch/mips/pci/pci.c
+++ b/arch/mips/pci/pci.c
@@ -122,51 +122,37 @@ 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;
+	struct of_pci_range_parser parser;
 
 	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_init(&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 */
+
+		switch (range.flags & IORESOURCE_TYPE_BITS) {
+		case IORESOURCE_IO:
 			pr_info("  IO 0x%016llx..0x%016llx\n",
-					addr, addr + size - 1);
+				range.cpu_addr,
+				range.cpu_addr + range.size - 1);
 			hose->io_map_base =
-				(unsigned long)ioremap(addr, size);
+				(unsigned long)ioremap(range.cpu_addr,
+						       range.size);
 			res = hose->io_resource;
-			res->flags = IORESOURCE_IO;
 			break;
-		case 2:		/* PCI Memory space */
-		case 3:		/* PCI 64 bits Memory space */
+		case IORESOURCE_MEM:
 			pr_info(" MEM 0x%016llx..0x%016llx\n",
-					addr, addr + size - 1);
+				range.cpu_addr,
+				range.cpu_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
-- 
1.7.0.4

[PATCH v9 3/3] of/pci: microblaze: convert to common of_pci_range_parser

[Andrew Murray]

This patch converts the pci_load_of_ranges function to use the new common
of_pci_range_parser.

Signed-off-by: Andrew Murray <Andrew.Murray@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
---
 arch/microblaze/pci/pci-common.c |  106 ++++++++++++++------------------------
 1 files changed, 38 insertions(+), 68 deletions(-)

diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index 9ea521e..ba9e4a1 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -658,67 +658,42 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar,
 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;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
 
 	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)
+	/* Check for ranges property */
+	if (of_pci_range_parser_init(&parser, dev))
 		return;
 
-	/* Parse it */
 	pr_debug("Parsing ranges property...\n");
-	while ((rlen -= np * 4) >= 0) {
+	for_each_of_pci_range(&parser, &range) {
 		/* 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);
+				range.pci_space, range.pci_addr);
 		pr_debug("cpu_addr:0x%016llx size:0x%016llx\n",
-					cpu_addr, size);
-
-		ranges += np;
+					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 (cpu_addr == OF_BAD_ADDR || size == 0)
+		if (range.cpu_addr == OF_BAD_ADDR || range.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 */
+		switch (range.flags & IORESOURCE_TYPE_BITS) {
+		case IORESOURCE_IO:
 			pr_info("  IO 0x%016llx..0x%016llx -> 0x%016llx\n",
-			       cpu_addr, cpu_addr + size - 1, pci_addr);
+				range.cpu_addr, range.cpu_addr + range.size - 1,
+				range.pci_addr);
 
 			/* We support only one IO range */
 			if (hose->pci_io_size) {
@@ -726,11 +701,12 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
 				continue;
 			}
 			/* On 32 bits, limit I/O space to 16MB */
-			if (size > 0x01000000)
-				size = 0x01000000;
+			if (range.size > 0x01000000)
+				range.size = 0x01000000;
 
 			/* 32 bits needs to map IOs here */
-			hose->io_base_virt = ioremap(cpu_addr, size);
+			hose->io_base_virt = ioremap(range.cpu_addr,
+						range.size);
 
 			/* Expect trouble if pci_addr is not 0 */
 			if (primary)
@@ -739,19 +715,20 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
 			/* 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;
+			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;
-			res->flags = IORESOURCE_IO;
-			res->start = pci_addr;
+			range.cpu_addr = range.pci_addr;
+
 			break;
-		case 2:		/* PCI Memory space */
-		case 3:		/* PCI 64 bits Memory space */
+		case IORESOURCE_MEM:
 			pr_info(" MEM 0x%016llx..0x%016llx -> 0x%016llx %s\n",
-			       cpu_addr, cpu_addr + size - 1, pci_addr,
-			       (pci_space & 0x40000000) ? "Prefetch" : "");
+				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) {
@@ -759,13 +736,13 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
 				continue;
 			}
 			/* Handles ISA memory hole space here */
-			if (pci_addr == 0) {
-				isa_mb = cpu_addr;
+			if (range.pci_addr == 0) {
+				isa_mb = range.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;
+					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
@@ -773,30 +750,23 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
 			 * hole. If they don't match, bugger.
 			 */
 			if (memno == 0 ||
-			    (isa_hole >= 0 && pci_addr != 0 &&
+			    (isa_hole >= 0 && range.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) {
+				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++];
-			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 (res != NULL)
+			of_pci_range_to_resource(&range, dev, res);
 	}
 
 	/* If there's an ISA hole and the pci_mem_offset is -not- matching
-- 
1.7.0.4