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The exclusion_bounce() routine compares unchanging values in the tag with

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unchanging values in the phys_avail array, so do the comparisons just once
at tag creation time and set a flag to remember the result.

Reviewed by:	cognet
This commit is contained in:
Ian Lepore 2014-07-29 02:34:32 +00:00
parent 751428ce88
commit 7c54a52475
1 changed files with 22 additions and 11 deletions
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33
sys/arm/arm/busdma_machdep-v6.c
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@ -64,7 +64,9 @@ __FBSDID("$FreeBSD$");
#include <machine/md_var.h>
#define MAX_BPAGES 64
#define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3
#define BUS_DMA_EXCL_BOUNCE BUS_DMA_BUS2
#define BUS_DMA_ALIGN_BOUNCE BUS_DMA_BUS3
#define BUS_DMA_COULD_BOUNCE (BUS_DMA_EXCL_BOUNCE | BUS_DMA_ALIGN_BOUNCE)
#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
struct bounce_zone;
@ -242,7 +244,7 @@ SYSINIT(busdma, SI_SUB_KMEM, SI_ORDER_FOURTH, busdma_init, NULL);
* express, so we take a fast out.
*/
static int
exclusion_bounce(vm_offset_t lowaddr, vm_offset_t highaddr)
exclusion_bounce_check(vm_offset_t lowaddr, vm_offset_t highaddr)
{
int i;
@ -258,6 +260,16 @@ exclusion_bounce(vm_offset_t lowaddr, vm_offset_t highaddr)
return (0);
}
/*
* Return true if the tag has an exclusion zone that could lead to bouncing.
*/
static __inline int
exclusion_bounce(bus_dma_tag_t dmat)
{
return (dmat->flags & BUS_DMA_EXCL_BOUNCE);
}
/*
* Return true if the given address does not fall on the alignment boundary.
*/
@ -436,17 +448,15 @@ bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
if (parent != NULL) {
newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
newtag->flags |= parent->flags & BUS_DMA_COULD_BOUNCE;
if (newtag->boundary == 0)
newtag->boundary = parent->boundary;
else if (parent->boundary != 0)
newtag->boundary = MIN(parent->boundary,
newtag->boundary);
if ((newtag->filter != NULL) ||
((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
newtag->flags |= BUS_DMA_COULD_BOUNCE;
if (newtag->filter == NULL) {
/*
* Short circuit looking at our parent directly
* Short circuit to looking at our parent directly
* since we have encapsulated all of its information
*/
newtag->filter = parent->filter;
@ -457,9 +467,10 @@ bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
atomic_add_int(&parent->ref_count, 1);
}
if (exclusion_bounce(newtag->lowaddr, newtag->highaddr)
|| alignment_bounce(newtag, 1))
newtag->flags |= BUS_DMA_COULD_BOUNCE;
if (exclusion_bounce_check(newtag->lowaddr, newtag->highaddr))
newtag->flags |= BUS_DMA_EXCL_BOUNCE;
if (alignment_bounce(newtag, 1))
newtag->flags |= BUS_DMA_ALIGN_BOUNCE;
/*
* Any request can auto-bounce due to cacheline alignment, in addition
@ -737,7 +748,7 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
* constraints is something that only the contig allocator can fulfill.
*/
if (bufzone != NULL && dmat->alignment <= bufzone->size &&
!exclusion_bounce(dmat->lowaddr, dmat->highaddr)) {
!exclusion_bounce(dmat)) {
*vaddr = uma_zalloc(bufzone->umazone, mflags);
} else if (dmat->nsegments >= btoc(dmat->maxsize) &&
dmat->alignment <= PAGE_SIZE && dmat->boundary == 0) {
@ -784,7 +795,7 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
bufzone = busdma_bufalloc_findzone(ba, dmat->maxsize);
if (bufzone != NULL && dmat->alignment <= bufzone->size &&
!exclusion_bounce(dmat->lowaddr, dmat->highaddr))
!exclusion_bounce(dmat))
uma_zfree(bufzone->umazone, vaddr);
else
kmem_free(kernel_arena, (vm_offset_t)vaddr, dmat->maxsize);