linux/arch/sparc64/kernel/iommu_common.h
David S. Miller 38192d52f1 [SPARC64]: Temporarily remove IOMMU merging code.
Changeset fde6a3c82d ("iommu sg merging:
sparc64: make iommu respect the segment size limits") broke sparc64
because whilst it added the segment limiting code to the first pass of
SG mapping (in prepare_sg()) it did not add matching code to the
second pass handling (in fill_sg())

As a result the two passes disagree where the segment boundaries
should be, resulting in OOPSes, DMA corruption, and corrupted
superblocks.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-06 04:12:25 -08:00

77 lines
2 KiB
C

/* $Id: iommu_common.h,v 1.5 2001/12/11 09:41:01 davem Exp $
* iommu_common.h: UltraSparc SBUS/PCI common iommu declarations.
*
* Copyright (C) 1999 David S. Miller (davem@redhat.com)
*/
#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 <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) (((addr)+IO_PAGE_SIZE-1)&IO_PAGE_MASK)
#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 unsigned long calc_npages(struct scatterlist *sglist, int nelems)
{
unsigned long i, npages = 0;
struct scatterlist *sg;
for_each_sg(sglist, sg, nelems, i) {
unsigned long paddr = SG_ENT_PHYS_ADDRESS(sg);
npages += iommu_num_pages(paddr, sg->length);
}
return npages;
}
/* You are _strongly_ advised to enable the following debugging code
* any time you make changes to the sg code below, run it for a while
* with filesystems mounted read-only before buying the farm... -DaveM
*/
#undef VERIFY_SG
#ifdef VERIFY_SG
extern void verify_sglist(struct scatterlist *sg, int nents, iopte_t *iopte, int npages);
#endif
/* Two addresses are "virtually contiguous" if and only if:
* 1) They are equal, or...
* 2) They are both on a page boundary
*/
#define VCONTIG(__X, __Y) (((__X) == (__Y)) || \
(((__X) | (__Y)) << (64UL - PAGE_SHIFT)) == 0UL)
extern unsigned long prepare_sg(struct device *dev, struct scatterlist *sg, int nents);