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Fix a coherent bus check in the arm64 busdma

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In the arm64 busdma we have an internal flag to signal when a tag is
for a cache-coherent device. In this case we don't need to adjust the
size and alignment of allocated buffers to be within a cache line.

The cache line adjustment was incorrectly using the coherent flag
passed in to bus_dma_tag_create and not the internal flag. Fix it to
use the latter to reduce the memory usage slightly.

Reviewed by:	bz
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34763
This commit is contained in:
Andrew Turner 2022-04-04 10:28:59 +01:00
parent bcd763b642
commit 3532bcd282
1 changed files with 12 additions and 9 deletions
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21
sys/arm64/arm64/busdma_bounce.c
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@ -228,6 +228,18 @@ bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
if ((flags & BUS_DMA_COHERENT) != 0) {
newtag->bounce_flags |= BF_COHERENT;
}
if (parent != NULL) {
if ((newtag->common.filter != NULL ||
(parent->bounce_flags & BF_COULD_BOUNCE) != 0))
newtag->bounce_flags |= BF_COULD_BOUNCE;
/* Copy some flags from the parent */
newtag->bounce_flags |= parent->bounce_flags & BF_COHERENT;
}
if ((newtag->bounce_flags & BF_COHERENT) != 0) {
newtag->alloc_alignment = newtag->common.alignment;
newtag->alloc_size = newtag->common.maxsize;
} else {
@ -243,15 +255,6 @@ bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
dcache_line_size);
}
if (parent != NULL) {
if ((newtag->common.filter != NULL ||
(parent->bounce_flags & BF_COULD_BOUNCE) != 0))
newtag->bounce_flags |= BF_COULD_BOUNCE;
/* Copy some flags from the parent */
newtag->bounce_flags |= parent->bounce_flags & BF_COHERENT;
}
if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
newtag->common.alignment > 1)
newtag->bounce_flags |= BF_COULD_BOUNCE;