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Commit 88452565 authored by Ivan Kokshaysky's avatar Ivan Kokshaysky Committed by Greg Kroah-Hartman
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PCI: clean up resource alignment management 



Done per Linus' request and suggestions. Linus has explained that
better than I'll be able to explain:

On Thu, Mar 27, 2008 at 10:12:10AM -0700, Linus Torvalds wrote:
> Actually, before we go any further, there might be a less intrusive
> alternative: add just a couple of flags to the resource flags field (we
> still have something like 8 unused bits on 32-bit), and use those to
> implement a generic "resource_alignment()" routine.
>
> Two flags would do it:
>
>  - IORESOURCE_SIZEALIGN: size indicates alignment (regular PCI device
>    resources)
>
>  - IORESOURCE_STARTALIGN: start field is alignment (PCI bus resources
>    during probing)
>
> and then the case of both flags zero (or both bits set) would actually be
> "invalid", and we would also clear the IORESOURCE_STARTALIGN flag when we
> actually allocate the resource (so that we don't use the "start" field as
> alignment incorrectly when it no longer indicates alignment).
>
> That wouldn't be totally generic, but it would have the nice property of
> automatically at least add sanity checking for that whole "res->start has
> the odd meaning of 'alignment' during probing" and remove the need for a
> new field, and it would allow us to have a generic "resource_alignment()"
> routine that just gets a resource pointer.

Besides, I removed IORESOURCE_BUS_HAS_VGA flag which was unused for ages.

Signed-off-by: default avatarIvan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent d75b3052

drivers/pci/probe.c

+3 −2
Original line number Diff line number Diff line
@@ -235,7 +235,7 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) 
			res->flags |= l & ~PCI_BASE_ADDRESS_IO_MASK;

		}

		res->end = res->start + (unsigned long) sz;

		res->flags |= pci_calc_resource_flags(l);

		res->flags |= pci_calc_resource_flags(l) | IORESOURCE_SIZEALIGN;

		if (is_64bit_memory(l)) {

			u32 szhi, lhi;
@@ -288,7 +288,8 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) 
			if (sz) {

				res->flags = (l & IORESOURCE_ROM_ENABLE) |

				  IORESOURCE_MEM | IORESOURCE_PREFETCH |

				  IORESOURCE_READONLY | IORESOURCE_CACHEABLE;

				  IORESOURCE_READONLY | IORESOURCE_CACHEABLE |

				  IORESOURCE_SIZEALIGN;

				res->start = l & PCI_ROM_ADDRESS_MASK;

				res->end = res->start + (unsigned long) sz;

			}

drivers/pci/setup-bus.c

+3 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ static void pbus_assign_resources_sorted(struct pci_bus *bus) 
		res = list->res;

		idx = res - &list->dev->resource[0];

		if (pci_assign_resource(list->dev, idx)) {

			/* FIXME: get rid of this */

			res->start = 0;

			res->end = 0;

			res->flags = 0;
@@ -327,6 +328,7 @@ static void pbus_size_io(struct pci_bus *bus) 
	/* Alignment of the IO window is always 4K */

	b_res->start = 4096;

	b_res->end = b_res->start + size - 1;

	b_res->flags |= IORESOURCE_STARTALIGN;

}



/* Calculate the size of the bus and minimal alignment which
@@ -401,6 +403,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long 
	}

	b_res->start = min_align;

	b_res->end = size + min_align - 1;

	b_res->flags |= IORESOURCE_STARTALIGN;

	return 1;

}

drivers/pci/setup-res.c

+23 −19
Original line number Diff line number Diff line
@@ -137,10 +137,16 @@ int pci_assign_resource(struct pci_dev *dev, int resno) 


	size = res->end - res->start + 1;

	min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;

	/* The bridge resources are special, as their

	   size != alignment. Sizing routines return

	   required alignment in the "start" field. */

	align = (resno < PCI_BRIDGE_RESOURCES) ? size : res->start;



	align = resource_alignment(res);

	if (!align) {

		printk(KERN_ERR "PCI: Cannot allocate resource (bogus "

			"alignment) %d [%llx:%llx] (flags %lx) of %s\n",

			resno, (unsigned long long)res->start,

			(unsigned long long)res->end, res->flags,

			pci_name(dev));

		return -EINVAL;

	}



	/* First, try exact prefetching match.. */

	ret = pci_bus_alloc_resource(bus, res, size, align, min,
@@ -164,7 +170,9 @@ int pci_assign_resource(struct pci_dev *dev, int resno) 
			res->flags & IORESOURCE_IO ? "I/O" : "mem",

			resno, (unsigned long long)size,

			(unsigned long long)res->start, pci_name(dev));

	} else if (resno < PCI_BRIDGE_RESOURCES) {

	} else {

		res->flags &= ~IORESOURCE_STARTALIGN;

		if (resno < PCI_BRIDGE_RESOURCES)

			pci_update_resource(dev, res, resno);

	}
@@ -226,29 +234,25 @@ void pdev_sort_resources(struct pci_dev *dev, struct resource_list *head) 
		if (r->flags & IORESOURCE_PCI_FIXED)

			continue;



		r_align = r->end - r->start;

		

		if (!(r->flags) || r->parent)

			continue;



		r_align = resource_alignment(r);

		if (!r_align) {

			printk(KERN_WARNING "PCI: Ignore bogus resource %d "

				"[%llx:%llx] of %s\n",

			printk(KERN_WARNING "PCI: bogus alignment of resource "

				"%d [%llx:%llx] (flags %lx) of %s\n",

				i, (unsigned long long)r->start,

				(unsigned long long)r->end, pci_name(dev));

				(unsigned long long)r->end, r->flags,

				pci_name(dev));

			continue;

		}

		r_align = (i < PCI_BRIDGE_RESOURCES) ? r_align + 1 : r->start;

		for (list = head; ; list = list->next) {

			resource_size_t align = 0;

			struct resource_list *ln = list->next;

			int idx;



			if (ln) {

				idx = ln->res - &ln->dev->resource[0];

				align = (idx < PCI_BRIDGE_RESOURCES) ?

					ln->res->end - ln->res->start + 1 :

					ln->res->start;

			}

			if (ln)

				align = resource_alignment(ln->res);



			if (r_align > align) {

				tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);

				if (!tmp)

include/linux/ioport.h

+4 −1
Original line number Diff line number Diff line
@@ -44,7 +44,9 @@ struct resource_list { 
#define IORESOURCE_CACHEABLE	0x00004000

#define IORESOURCE_RANGELENGTH	0x00008000

#define IORESOURCE_SHADOWABLE	0x00010000

#define IORESOURCE_BUS_HAS_VGA	0x00080000



#define IORESOURCE_SIZEALIGN	0x00020000	/* size indicates alignment */

#define IORESOURCE_STARTALIGN	0x00040000	/* start field is alignment */



#define IORESOURCE_DISABLED	0x10000000

#define IORESOURCE_UNSET	0x20000000
@@ -110,6 +112,7 @@ extern int allocate_resource(struct resource *root, struct resource *new, 
			     void *alignf_data);

int adjust_resource(struct resource *res, resource_size_t start,

		    resource_size_t size);

resource_size_t resource_alignment(struct resource *res);



/* Convenience shorthand with allocation */

#define request_region(start,n,name)	__request_region(&ioport_resource, (start), (n), (name))

kernel/resource.c

+18 −0
Original line number Diff line number Diff line
@@ -486,6 +486,24 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t 


EXPORT_SYMBOL(adjust_resource);



/**

 * resource_alignment - calculate resource's alignment

 * @res: resource pointer

 *

 * Returns alignment on success, 0 (invalid alignment) on failure.

 */

resource_size_t resource_alignment(struct resource *res)

{

	switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {

	case IORESOURCE_SIZEALIGN:

		return res->end - res->start + 1;

	case IORESOURCE_STARTALIGN:

		return res->start;

	default:

		return 0;

	}

}



/*

 * This is compatibility stuff for IO resources.

 *