Patchwork [v7,2/3] of/pci: Provide support for parsing PCI DT ranges property

login
register
mail settings
Submitter Andrew Murray
Date April 16, 2013, 10:18 a.m.
Message ID <1366107508-12672-3-git-send-email-Andrew.Murray@arm.com>
Download mbox | patch
Permalink /patch/236916/
State Not Applicable
Headers show

Comments

Andrew Murray - April 16, 2013, 10:18 a.m.
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).

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>
---
 drivers/of/address.c       |   67 ++++++++++++++++++++++++++
 drivers/of/of_pci.c        |  113 ++++++++++++++++----------------------------
 include/linux/of_address.h |   46 ++++++++++++++++++
 3 files changed, 154 insertions(+), 72 deletions(-)
Grant Likely - April 18, 2013, 1:44 p.m.
On Tue, 16 Apr 2013 11:18:27 +0100, Andrew Murray <Andrew.Murray@arm.com> wrote:
> 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).
> 
> 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>

Acked-by: Grant Likely <grant.likely@secretlab.ca>

But comments below...

> ---
>  drivers/of/address.c       |   67 ++++++++++++++++++++++++++
>  drivers/of/of_pci.c        |  113 ++++++++++++++++----------------------------
>  include/linux/of_address.h |   46 ++++++++++++++++++
>  3 files changed, 154 insertions(+), 72 deletions(-)
> 
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 04da786..6eec70c 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(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);

"of_pci_range_parser_init" would be a clearer name

> +struct of_pci_range *of_pci_process_ranges(struct of_pci_range_parser *parser,
> +						struct of_pci_range *range)

Similarly, "of_pci_range_parser_one" would be more consistent.

> +{
> +	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_process_ranges);
> +
>  #endif /* CONFIG_PCI */
>  
>  /*
> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> index 1626172..e5ab604 100644
> --- a/drivers/of/of_pci.c
> +++ b/drivers/of/of_pci.c
> @@ -2,6 +2,7 @@
>  #include <linux/export.h>
>  #include <linux/of.h>
>  #include <linux/of_pci.h>
> +#include <linux/of_address.h>
>  #include <asm/prom.h>
>  
>  #if defined(CONFIG_PPC32) || defined(CONFIG_PPC64) || defined(CONFIG_MICROBLAZE)
> @@ -82,67 +83,43 @@ EXPORT_SYMBOL_GPL(of_pci_find_child_device);
>  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;
> +	u32 res_type;
>  
>  	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(&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);

Tip: the diff on this function would be a whole lot simpler if the
above locals were kept, but updated from the ranges structure. Not at
all a big problem, but it is something that makes changes like this
easier to review. The removal of the locals could also be split into a
separate patch to end up with the same result.

> -
> -		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;
> +		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);

Nit: the patch changed whitespace on the pr_debug() statements, so even
though the first line of each is identical, they look different in the
patch.

>  
>  		/* 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;

Can this also be rolled into the parsing iterator?

>  
> -		/* 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 */
> +		res_type = range.flags & IORESOURCE_TYPE_BITS;
> +		if (res_type == IORESOURCE_IO) {

Why the change from switch() to an if/else if sequence?

But those are mostly nitpicks. If this is deferred to v3.10 then I would
suggest fixing them up and posting for another round of review.

g.
Andrew Murray - April 18, 2013, 2:24 p.m.
On Thu, Apr 18, 2013 at 02:44:01PM +0100, Grant Likely wrote:
> On Tue, 16 Apr 2013 11:18:27 +0100, Andrew Murray <Andrew.Murray@arm.com> wrote:
> > 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).
> > 
> > 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>
> 
> Acked-by: Grant Likely <grant.likely@secretlab.ca>
> 
> But comments below...
> 
> > ---
> >  drivers/of/address.c       |   67 ++++++++++++++++++++++++++
> >  drivers/of/of_pci.c        |  113 ++++++++++++++++----------------------------
> >  include/linux/of_address.h |   46 ++++++++++++++++++
> >  3 files changed, 154 insertions(+), 72 deletions(-)
> > 
> > diff --git a/drivers/of/address.c b/drivers/of/address.c
> > index 04da786..6eec70c 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(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);
> 
> "of_pci_range_parser_init" would be a clearer name
> 
> > +struct of_pci_range *of_pci_process_ranges(struct of_pci_range_parser *parser,
> > +						struct of_pci_range *range)
> 
> Similarly, "of_pci_range_parser_one" would be more consistent.
> 
> > +{
> > +	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_process_ranges);
> > +
> >  #endif /* CONFIG_PCI */
> >  
> >  /*
> > diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> > index 1626172..e5ab604 100644
> > --- a/drivers/of/of_pci.c
> > +++ b/drivers/of/of_pci.c
> > @@ -2,6 +2,7 @@
> >  #include <linux/export.h>
> >  #include <linux/of.h>
> >  #include <linux/of_pci.h>
> > +#include <linux/of_address.h>
> >  #include <asm/prom.h>
> >  
> >  #if defined(CONFIG_PPC32) || defined(CONFIG_PPC64) || defined(CONFIG_MICROBLAZE)
> > @@ -82,67 +83,43 @@ EXPORT_SYMBOL_GPL(of_pci_find_child_device);
> >  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;
> > +	u32 res_type;
> >  
> >  	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(&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);
> 
> Tip: the diff on this function would be a whole lot simpler if the
> above locals were kept, but updated from the ranges structure. Not at
> all a big problem, but it is something that makes changes like this
> easier to review. The removal of the locals could also be split into a
> separate patch to end up with the same result.
> 
> > -
> > -		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;
> > +		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);
> 
> Nit: the patch changed whitespace on the pr_debug() statements, so even
> though the first line of each is identical, they look different in the
> patch.
> 
> >  
> >  		/* 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;
> 
> Can this also be rolled into the parsing iterator?
> 

Yes I think that would make sense.

> >  
> > -		/* 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 */
> > +		res_type = range.flags & IORESOURCE_TYPE_BITS;
> > +		if (res_type == IORESOURCE_IO) {
> 
> Why the change from switch() to an if/else if sequence?

Russell King suggested this change - see 
https://patchwork.kernel.org/patch/2323941/

> 
> But those are mostly nitpicks. If this is deferred to v3.10 then I would
> suggest fixing them up and posting for another round of review.

Thanks for the feedback. I'll update the patch in the future.

Andrew Murray
Grant Likely - April 18, 2013, 3:29 p.m.
On Thu, Apr 18, 2013 at 3:24 PM, Andrew Murray <andrew.murray@arm.com> wrote:
> On Thu, Apr 18, 2013 at 02:44:01PM +0100, Grant Likely wrote:
>> On Tue, 16 Apr 2013 11:18:27 +0100, Andrew Murray <Andrew.Murray@arm.com> wrote:
>> >             /* Act based on address space type */
>> >             res = NULL;
>> > -           switch ((pci_space >> 24) & 0x3) {
>> > -           case 1:         /* PCI IO space */
>> > +           res_type = range.flags & IORESOURCE_TYPE_BITS;
>> > +           if (res_type == IORESOURCE_IO) {
>>
>> Why the change from switch() to an if/else if sequence?
>
> Russell King suggested this change - see
> https://patchwork.kernel.org/patch/2323941/

Umm, that isn't what that link shows. That link shows the patch
already changing to an if/else if construct, and rmk is commenting on
that.

g.
Andrew Murray - April 18, 2013, 3:38 p.m.
On Thu, Apr 18, 2013 at 04:29:54PM +0100, Grant Likely wrote:
> On Thu, Apr 18, 2013 at 3:24 PM, Andrew Murray <andrew.murray@arm.com> wrote:
> > On Thu, Apr 18, 2013 at 02:44:01PM +0100, Grant Likely wrote:
> >> On Tue, 16 Apr 2013 11:18:27 +0100, Andrew Murray <Andrew.Murray@arm.com> wrote:
> >> >             /* Act based on address space type */
> >> >             res = NULL;
> >> > -           switch ((pci_space >> 24) & 0x3) {
> >> > -           case 1:         /* PCI IO space */
> >> > +           res_type = range.flags & IORESOURCE_TYPE_BITS;
> >> > +           if (res_type == IORESOURCE_IO) {
> >>
> >> Why the change from switch() to an if/else if sequence?
> >
> > Russell King suggested this change - see
> > https://patchwork.kernel.org/patch/2323941/
> 
> Umm, that isn't what that link shows. That link shows the patch
> already changing to an if/else if construct, and rmk is commenting on
> that.

Arh yes sorry about that. I can't find or remember any good reason why I
changed it from a switch to an if/else :\

Andrew Murray
Andrew Murray - April 22, 2013, 10:57 a.m.
On Thu, Apr 18, 2013 at 02:44:01PM +0100, Grant Likely wrote:
> On Tue, 16 Apr 2013 11:18:27 +0100, Andrew Murray <Andrew.Murray@arm.com> wrote:

> 
> Acked-by: Grant Likely <grant.likely@secretlab.ca>
> 
> But comments below...
> 

I've updated the patchset (now v8) to reflect your feedback, after a closer
look...

> > -
> > -		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;
> > +		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);
> 
> Nit: the patch changed whitespace on the pr_debug() statements, so even
> though the first line of each is identical, they look different in the
> patch.
> 

Actually the first line isn't identical, the original file was inconsistent
with its use of spaces between ':' and '0x%0' - my patch ensured that there
was always a space. I guess this could have been done as a separate patch.

> >  
> >  		/* 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;
> 
> Can this also be rolled into the parsing iterator?
> 

I decided not to do this. Mainly because ARM drivers use the parser directly
(instead of pci_process_bridge_OF_ranges function) and it seemed perfectly
valid for the parser to return a range of size 0 if that is what was present in
the DT.

> >  
> > -		/* 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 */
> > +		res_type = range.flags & IORESOURCE_TYPE_BITS;
> > +		if (res_type == IORESOURCE_IO) {
> 
> Why the change from switch() to an if/else if sequence?

I think this was an artifact of the patches evolution, I've reverted back to
the switch.

> 
> But those are mostly nitpicks. If this is deferred to v3.10 then I would
> suggest fixing them up and posting for another round of review.

Andrew Murray

Patch

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 04da786..6eec70c 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(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);
+
+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 (!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_process_ranges);
+
 #endif /* CONFIG_PCI */
 
 /*
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 1626172..e5ab604 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -2,6 +2,7 @@ 
 #include <linux/export.h>
 #include <linux/of.h>
 #include <linux/of_pci.h>
+#include <linux/of_address.h>
 #include <asm/prom.h>
 
 #if defined(CONFIG_PPC32) || defined(CONFIG_PPC64) || defined(CONFIG_MICROBLAZE)
@@ -82,67 +83,43 @@  EXPORT_SYMBOL_GPL(of_pci_find_child_device);
 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;
+	u32 res_type;
 
 	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(&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);
-		pr_debug("cpu_addr:0x%016llx size:0x%016llx\n",
-					cpu_addr, size);
-
-		ranges += np;
+		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 (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 */
+		res_type = range.flags & IORESOURCE_TYPE_BITS;
+		if (res_type == 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) {
@@ -151,11 +128,12 @@  void pci_process_bridge_OF_ranges(struct pci_controller *hose,
 			}
 #if (!IS_ENABLED(CONFIG_64BIT))
 			/* 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)
@@ -165,19 +143,18 @@  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;
-			break;
-		case 2:		/* PCI Memory space */
-		case 3:		/* PCI 64 bits Memory space */
+			range.cpu_addr = range.pci_addr;
+		} else if (res_type == 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) {
@@ -185,13 +162,13 @@  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
@@ -199,30 +176,22 @@  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
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 0506eb5..1cfb779 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_process_ranges(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 +57,10 @@  static inline unsigned long pci_address_to_pio(phys_addr_t addr) { return -1; }
 #define pci_address_to_pio pci_address_to_pio
 #endif
 
+extern int of_pci_range_parser(struct of_pci_range_parser *parser,
+			struct device_node *node);
+extern 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 +87,18 @@  static inline const __be32 *of_get_address(struct device_node *dev, int index,
 {
 	return NULL;
 }
+
+static inline int of_pci_range_parser(struct of_pci_range_parser *parser,
+			struct device_node *node)
+{
+	return -1;
+}
+
+static inline 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 */