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Add a quick hack to ensure that bus_dmamem_alloc properly aligns

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small allocations with large alignment requirements.

Add a panic to detect cases where we've still failed to properly align.
This commit is contained in:
Mike Silbersack 2006-05-28 18:30:36 +00:00
parent 39e2bd0bdb
commit 0d65566db8
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=159011
1 changed files with 14 additions and 2 deletions
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16
sys/i386/i386/busdma_machdep.c
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@ -495,7 +495,16 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
}
}
/*
* XXX:
* (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
* alignment guarantees of malloc need to be nailed down, and the
* code below should be rewritten to take that into account.
*
* In the meantime, we'll panic if malloc gets it wrong.
*/
if ((dmat->maxsize <= PAGE_SIZE) &&
(dmat->alignment < dmat->maxsize) &&
dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
} else {
@ -513,6 +522,8 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
__func__, dmat, dmat->flags, ENOMEM);
return (ENOMEM);
} else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) {
panic("bus_dmamem_alloc failed to align memory properly.");
}
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
__func__, dmat, dmat->flags, ENOMEM);
@ -532,8 +543,9 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
*/
if (map != NULL)
panic("bus_dmamem_free: Invalid map freed\n");
if ((dmat->maxsize <= PAGE_SIZE)
&& dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
if ((dmat->maxsize <= PAGE_SIZE) &&
(dmat->alignment < dmat->maxsize) &&
dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
free(vaddr, M_DEVBUF);
else {
contigfree(vaddr, dmat->maxsize, M_DEVBUF);