Patchwork [PATCHv10,2/9] of/pci: Provide support for parsing PCI DT ranges property

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Submitter Thomas Petazzoni
Date May 16, 2013, 3:55 p.m.
Message ID <1368719725-21265-3-git-send-email-thomas.petazzoni@free-electrons.com>
Download mbox | patch
Permalink /patch/244381/
State Not Applicable
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Comments

Thomas Petazzoni - May 16, 2013, 3:55 p.m.
From: Andrew Murray <Andrew.Murray@arm.com>

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(+)
Jason - May 19, 2013, 8:31 p.m.
On Thu, May 16, 2013 at 05:55:17PM +0200, Thomas Petazzoni wrote:
> From: Andrew Murray <Andrew.Murray@arm.com>
> 
> 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(+)

patches 2, 3, and 4 applied to mvebu/of_pci to facilitate others
(LinusW) basing their work off of it.

thx,

Jason.
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Linus Walleij - May 20, 2013, 7:03 a.m.
On Sun, May 19, 2013 at 10:31 PM, Jason Cooper <jason@lakedaemon.net> wrote:

> patches 2, 3, and 4 applied to mvebu/of_pci to facilitate others
> (LinusW) basing their work off of it.

Thanks, is this going to be pulled into ARM SoC soon-ish?

I think Arnd may need this for some PCI work too.

Yours,
Linus Walleij
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Jason - May 20, 2013, 5:08 p.m.
On Mon, May 20, 2013 at 09:03:00AM +0200, Linus Walleij wrote:
> On Sun, May 19, 2013 at 10:31 PM, Jason Cooper <jason@lakedaemon.net> wrote:
> 
> > patches 2, 3, and 4 applied to mvebu/of_pci to facilitate others
> > (LinusW) basing their work off of it.
> 
> Thanks, is this going to be pulled into ARM SoC soon-ish?
> 
> I think Arnd may need this for some PCI work too.

I was half expecting -rc2 to drop yesterday.  Since it didn't, I'll go
ahead and send another round of PRs, including this one.  Probably today
or tomorrow.

thx,

Jason.
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Patch

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 */