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PCI: clean up resource alignment management

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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: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Ivan Kokshaysky
2008-03-30 19:50:14 +04:00
committed by Greg Kroah-Hartman
parent d75b305295
commit 884525655d
5 changed files with 51 additions and 22 deletions
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include/linux/ioport.h
+4 -1
View File
@@ -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))