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Allow static DMA allocations that allow for enough segments to do page-sized

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segments for the entire allocation to use kmem_alloc_attr() to allocate
KVM rather than using kmem_alloc_contig().  This avoids requiring
a single physically contiguous chunk in this case.

Submitted by:	Peter Jeremy (original version)
MFC after:	1 month
This commit is contained in:
John Baldwin 2012-08-17 14:14:25 +00:00
parent 9424879158
commit 2f36da87cb
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=239354
1 changed files with 7 additions and 6 deletions
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13
sys/x86/x86/busdma_machdep.c
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@ -533,13 +533,14 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
attr == VM_MEMATTR_DEFAULT) {
*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
} else if (dmat->nsegments >= btoc(dmat->maxsize) &&
dmat->alignment <= PAGE_SIZE &&
(dmat->boundary == 0 || dmat->boundary >= dmat->lowaddr)) {
/* Page-based multi-segment allocations allowed */
*vaddr = (void *)kmem_alloc_attr(kernel_map, dmat->maxsize,
mflags, 0ul, dmat->lowaddr, attr);
*mapp = &contig_dmamap;
} else {
/*
* XXX Use Contigmalloc until it is merged into this facility
* and handles multi-seg allocations. Nobody is doing
* multi-seg allocations yet though.
* XXX Certain AGP hardware does.
*/
*vaddr = (void *)kmem_alloc_contig(kernel_map, dmat->maxsize,
mflags, 0ul, dmat->lowaddr, dmat->alignment ?
dmat->alignment : 1ul, dmat->boundary, attr);