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linux-next/drivers/parisc/iommu-helpers.h
FUJITA Tomonori 7c8cda625a iommu: parisc: pass struct device to iommu_alloc_range
This adds struct device argument to sba_alloc_range and ccio_alloc_range, a
preparation for modifications to fix the IOMMU segment boundary problem.  This
change enables ccio_alloc_range to access to LLD's segment boundary limits.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:17 -08:00

177 lines
4.5 KiB
C

/**
* iommu_fill_pdir - Insert coalesced scatter/gather chunks into the I/O Pdir.
* @ioc: The I/O Controller.
* @startsg: The scatter/gather list of coalesced chunks.
* @nents: The number of entries in the scatter/gather list.
* @hint: The DMA Hint.
*
* This function inserts the coalesced scatter/gather list chunks into the
* I/O Controller's I/O Pdir.
*/
static inline unsigned int
iommu_fill_pdir(struct ioc *ioc, struct scatterlist *startsg, int nents,
unsigned long hint,
void (*iommu_io_pdir_entry)(u64 *, space_t, unsigned long,
unsigned long))
{
struct scatterlist *dma_sg = startsg; /* pointer to current DMA */
unsigned int n_mappings = 0;
unsigned long dma_offset = 0, dma_len = 0;
u64 *pdirp = NULL;
/* Horrible hack. For efficiency's sake, dma_sg starts one
* entry below the true start (it is immediately incremented
* in the loop) */
dma_sg--;
while (nents-- > 0) {
unsigned long vaddr;
long size;
DBG_RUN_SG(" %d : %08lx/%05x %08lx/%05x\n", nents,
(unsigned long)sg_dma_address(startsg), cnt,
sg_virt_addr(startsg), startsg->length
);
/*
** Look for the start of a new DMA stream
*/
if (sg_dma_address(startsg) & PIDE_FLAG) {
u32 pide = sg_dma_address(startsg) & ~PIDE_FLAG;
BUG_ON(pdirp && (dma_len != sg_dma_len(dma_sg)));
dma_sg++;
dma_len = sg_dma_len(startsg);
sg_dma_len(startsg) = 0;
dma_offset = (unsigned long) pide & ~IOVP_MASK;
n_mappings++;
#if defined(ZX1_SUPPORT)
/* Pluto IOMMU IO Virt Address is not zero based */
sg_dma_address(dma_sg) = pide | ioc->ibase;
#else
/* SBA, ccio, and dino are zero based.
* Trying to save a few CPU cycles for most users.
*/
sg_dma_address(dma_sg) = pide;
#endif
pdirp = &(ioc->pdir_base[pide >> IOVP_SHIFT]);
prefetchw(pdirp);
}
BUG_ON(pdirp == NULL);
vaddr = sg_virt_addr(startsg);
sg_dma_len(dma_sg) += startsg->length;
size = startsg->length + dma_offset;
dma_offset = 0;
#ifdef IOMMU_MAP_STATS
ioc->msg_pages += startsg->length >> IOVP_SHIFT;
#endif
do {
iommu_io_pdir_entry(pdirp, KERNEL_SPACE,
vaddr, hint);
vaddr += IOVP_SIZE;
size -= IOVP_SIZE;
pdirp++;
} while(unlikely(size > 0));
startsg++;
}
return(n_mappings);
}
/*
** First pass is to walk the SG list and determine where the breaks are
** in the DMA stream. Allocates PDIR entries but does not fill them.
** Returns the number of DMA chunks.
**
** Doing the fill separate from the coalescing/allocation keeps the
** code simpler. Future enhancement could make one pass through
** the sglist do both.
*/
static inline unsigned int
iommu_coalesce_chunks(struct ioc *ioc, struct device *dev,
struct scatterlist *startsg, int nents,
int (*iommu_alloc_range)(struct ioc *, struct device *, size_t))
{
struct scatterlist *contig_sg; /* contig chunk head */
unsigned long dma_offset, dma_len; /* start/len of DMA stream */
unsigned int n_mappings = 0;
unsigned int max_seg_size = dma_get_max_seg_size(dev);
while (nents > 0) {
/*
** Prepare for first/next DMA stream
*/
contig_sg = startsg;
dma_len = startsg->length;
dma_offset = sg_virt_addr(startsg) & ~IOVP_MASK;
/* PARANOID: clear entries */
sg_dma_address(startsg) = 0;
sg_dma_len(startsg) = 0;
/*
** This loop terminates one iteration "early" since
** it's always looking one "ahead".
*/
while(--nents > 0) {
unsigned long prevstartsg_end, startsg_end;
prevstartsg_end = sg_virt_addr(startsg) +
startsg->length;
startsg++;
startsg_end = sg_virt_addr(startsg) +
startsg->length;
/* PARANOID: clear entries */
sg_dma_address(startsg) = 0;
sg_dma_len(startsg) = 0;
/*
** First make sure current dma stream won't
** exceed DMA_CHUNK_SIZE if we coalesce the
** next entry.
*/
if(unlikely(ALIGN(dma_len + dma_offset + startsg->length,
IOVP_SIZE) > DMA_CHUNK_SIZE))
break;
if (startsg->length + dma_len > max_seg_size)
break;
/*
** Next see if we can append the next chunk (i.e.
** it must end on one page and begin on another
*/
if (unlikely(((prevstartsg_end | sg_virt_addr(startsg)) & ~PAGE_MASK) != 0))
break;
dma_len += startsg->length;
}
/*
** End of DMA Stream
** Terminate last VCONTIG block.
** Allocate space for DMA stream.
*/
sg_dma_len(contig_sg) = dma_len;
dma_len = ALIGN(dma_len + dma_offset, IOVP_SIZE);
sg_dma_address(contig_sg) =
PIDE_FLAG
| (iommu_alloc_range(ioc, dev, dma_len) << IOVP_SHIFT)
| dma_offset;
n_mappings++;
}
return n_mappings;
}