Subject: Re: [RFC/PATCH 4/14] powerpc: Fix powerpc 32 bits resource fixup for 64 bits resources

From: Vitaly Bordug <[email-masked]>
Date: Thu, 22 Nov 2007 21:31:23 +0300

On Wed, 21 Nov 2007 17:16:21 +1100
Benjamin Herrenschmidt wrote:

> The 32bits powerpc resource fixup code uses unsigned longs to do the
> offseting of resources which overflows on platforms such as 4xx where
> resources can be 64 bits.
> 
> This fixes it by using resource_size_t instead.
> 
> However, the IO stuff does rely on some 32 bits arithmetic, so we hack
> by cropping the result of the fixups for IO resources with a 32 bits
> mask.
> 
> This isn't the prettiest but should work for now until we change the
> 32 bits PCI code to do IO mappings like 64 bits does, within a
> reserved are of the kernel address space.
> 
> Signed-off-by: Benjamin Herrenschmidt <[email-masked]>
Acked-by: Vitaly Bordug <[email-masked]>
> ---
Verified on Freescale 83xx and should work for other 32bit stuff.

> This needs some regression testing.
> 
>  arch/powerpc/kernel/pci_32.c |   44
> +++++++++++++++++++++++-------------------- 1 file changed, 24
> insertions(+), 20 deletions(-)
> 
> Index: linux-work/arch/powerpc/kernel/pci_32.c
> ===================================================================
> --- linux-work.orig/arch/powerpc/kernel/pci_32.c	2007-11-16
> 15:48:27.000000000 +1100 +++
> linux-work/arch/powerpc/kernel/pci_32.c	2007-11-16
> 15:55:54.000000000 +1100 @@ -104,7 +104,7 @@
> pcibios_fixup_resources(struct pci_dev * { struct pci_controller*
> hose = (struct pci_controller *)dev->sysdata; int i;
> -	unsigned long offset;
> +	resource_size_t offset, mask;
>  
>  	if (!hose) {
>  		printk(KERN_ERR "No hose for PCI dev %s!\n",
> pci_name(dev)); @@ -123,15 +123,17 @@ pcibios_fixup_resources(struct
> pci_dev * continue;
>  		}
>  		offset = 0;
> +		mask = (resource_size_t)-1;
>  		if (res->flags & IORESOURCE_MEM) {
>  			offset = hose->pci_mem_offset;
>  		} else if (res->flags & IORESOURCE_IO) {
>  			offset = (unsigned long) hose->io_base_virt
>  				- isa_io_base;
> +			mask = 0xffffffffu;
>  		}
>  		if (offset != 0) {
> -			res->start += offset;
> -			res->end += offset;
> +			res->start = (res->start + offset) & mask;
> +			res->end = (res->end + offset) & mask;
>  			DBG("Fixup res %d (%lx) of dev %s: %llx ->
> %llx\n", i, res->flags, pci_name(dev),
>  			    (u64)res->start - offset,
> (u64)res->start); @@ -147,30 +149,32 @@
> DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID,		PC void
> pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region
> *region, struct resource *res) {
> -	unsigned long offset = 0;
> +	resource_size_t offset = 0, mask = (resource_size_t)-1;
>  	struct pci_controller *hose = dev->sysdata;
>  
> -	if (hose && res->flags & IORESOURCE_IO)
> +	if (hose && res->flags & IORESOURCE_IO) {
>  		offset = (unsigned long)hose->io_base_virt -
> isa_io_base;
> -	else if (hose && res->flags & IORESOURCE_MEM)
> +		mask = 0xffffffffu;
> +	} else if (hose && res->flags & IORESOURCE_MEM)
>  		offset = hose->pci_mem_offset;
> -	region->start = res->start - offset;
> -	region->end = res->end - offset;
> +	region->start = (res->start - offset) & mask;
> +	region->end = (res->end - offset) & mask;
>  }
>  EXPORT_SYMBOL(pcibios_resource_to_bus);
>  
>  void pcibios_bus_to_resource(struct pci_dev *dev, struct resource
> *res, struct pci_bus_region *region)
>  {
> -	unsigned long offset = 0;
> +	resource_size_t offset = 0, mask = (resource_size_t)-1;
>  	struct pci_controller *hose = dev->sysdata;
>  
> -	if (hose && res->flags & IORESOURCE_IO)
> +	if (hose && res->flags & IORESOURCE_IO) {
>  		offset = (unsigned long)hose->io_base_virt -
> isa_io_base;
> -	else if (hose && res->flags & IORESOURCE_MEM)
> +		mask = 0xffffffffu;
> +	} else if (hose && res->flags & IORESOURCE_MEM)
>  		offset = hose->pci_mem_offset;
> -	res->start = region->start + offset;
> -	res->end = region->end + offset;
> +	res->start = (region->start + offset) & mask;
> +	res->end = (region->end + offset) & mask;
>  }
>  EXPORT_SYMBOL(pcibios_bus_to_resource);
>  
> @@ -334,9 +338,9 @@ static int __init
>  pci_relocate_bridge_resource(struct pci_bus *bus, int i)
>  {
>  	struct resource *res, *pr, *conflict;
> -	unsigned long try, size;
> -	int j;
> +	resource_size_t try, size;
>  	struct pci_bus *parent = bus->parent;
> +	int j;
>  
>  	if (parent == NULL) {
>  		/* shouldn't ever happen */
> @@ -438,7 +442,7 @@ update_bridge_resource(struct pci_dev *d
>  	u8 io_base_lo, io_limit_lo;
>  	u16 mem_base, mem_limit;
>  	u16 cmd;
> -	unsigned long start, end, off;
> +	resource_size_t start, end, off;
>  	struct pci_controller *hose = dev->sysdata;
>  
>  	if (!hose) {
> @@ -1157,8 +1161,8 @@ void pcibios_fixup_bus(struct pci_bus *b
>  			res->end = IO_SPACE_LIMIT;
>  			res->flags = IORESOURCE_IO;
>  		}
> -		res->start += io_offset;
> -		res->end += io_offset;
> +		res->start = (res->start + io_offset) & 0xffffffffu;
> +		res->end = (res->end + io_offset) & 0xffffffffu;
>  
>  		for (i = 0; i < 3; ++i) {
>  			res = &hose->mem_resources[i];
> @@ -1183,8 +1187,8 @@ void pcibios_fixup_bus(struct pci_bus *b
>  			if (!res->flags || bus->self->transparent)
>  				continue;
>  			if (io_offset && (res->flags &
> IORESOURCE_IO)) {
> -				res->start += io_offset;
> -				res->end += io_offset;
> +				res->start = (res->start +
> io_offset) & 0xffffffffu;
> +				res->end = (res->end + io_offset) &
> 0xffffffffu; } else if (hose->pci_mem_offset
>  				   && (res->flags & IORESOURCE_MEM))
> { res->start += hose->pci_mem_offset;
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-- 
Sincerely, Vitaly