linux/arch/sparc64/kernel/iommu_common.h
Andrea Righi 27ac792ca0 PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
boundary. For example:

	u64 val = PAGE_ALIGN(size);

always returns a value < 4GB even if size is greater than 4GB.

The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
example):

#define PAGE_SHIFT      12
#define PAGE_SIZE       (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK       (~(PAGE_SIZE-1))
...
#define PAGE_ALIGN(addr)       (((addr)+PAGE_SIZE-1)&PAGE_MASK)

The "~" is performed on a 32-bit value, so everything in "and" with
PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
Using the ALIGN() macro seems to be the right way, because it uses
typeof(addr) for the mask.

Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
include/linux/mm.h.

See also lkml discussion: http://lkml.org/lkml/2008/6/11/237

[akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
[akpm@linux-foundation.org: fix v850]
[akpm@linux-foundation.org: fix powerpc]
[akpm@linux-foundation.org: fix arm]
[akpm@linux-foundation.org: fix mips]
[akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
[akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
[akpm@linux-foundation.org: fix powerpc]
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:21 -07:00

70 lines
1.7 KiB
C

/* iommu_common.h: UltraSparc SBUS/PCI common iommu declarations.
*
* Copyright (C) 1999, 2008 David S. Miller (davem@davemloft.net)
*/
#ifndef _IOMMU_COMMON_H
#define _IOMMU_COMMON_H
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/device.h>
#include <linux/iommu-helper.h>
#include <asm/iommu.h>
#include <asm/scatterlist.h>
/*
* These give mapping size of each iommu pte/tlb.
*/
#define IO_PAGE_SHIFT 13
#define IO_PAGE_SIZE (1UL << IO_PAGE_SHIFT)
#define IO_PAGE_MASK (~(IO_PAGE_SIZE-1))
#define IO_PAGE_ALIGN(addr) ALIGN(addr, IO_PAGE_SIZE)
#define IO_TSB_ENTRIES (128*1024)
#define IO_TSB_SIZE (IO_TSB_ENTRIES * 8)
/*
* This is the hardwired shift in the iotlb tag/data parts.
*/
#define IOMMU_PAGE_SHIFT 13
#define SG_ENT_PHYS_ADDRESS(SG) (__pa(sg_virt((SG))))
static inline unsigned long iommu_num_pages(unsigned long vaddr,
unsigned long slen)
{
unsigned long npages;
npages = IO_PAGE_ALIGN(vaddr + slen) - (vaddr & IO_PAGE_MASK);
npages >>= IO_PAGE_SHIFT;
return npages;
}
static inline int is_span_boundary(unsigned long entry,
unsigned long shift,
unsigned long boundary_size,
struct scatterlist *outs,
struct scatterlist *sg)
{
unsigned long paddr = SG_ENT_PHYS_ADDRESS(outs);
int nr = iommu_num_pages(paddr, outs->dma_length + sg->length);
return iommu_is_span_boundary(entry, nr, shift, boundary_size);
}
extern unsigned long iommu_range_alloc(struct device *dev,
struct iommu *iommu,
unsigned long npages,
unsigned long *handle);
extern void iommu_range_free(struct iommu *iommu,
dma_addr_t dma_addr,
unsigned long npages);
#endif /* _IOMMU_COMMON_H */