d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

busdma: Add an internal BUS_DMA_FORCE_MAP flag to x86 bounce_busdma

Browse Source 
Use this flag to indicate that busdma should allocate a map structure
even no bouncing is required to satisfy the tag's constraints.  This
will be used for KMSAN.

Also fix a memory leak that can occur if the kernel fails to allocate
bounce pages in bounce_bus_dmamap_create().

Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D31338
This commit is contained in:
Mark Johnston 2021-08-10 17:11:43 -04:00
parent 1263022e39
commit 3a1802fef4
1 changed files with 25 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
sys/x86/x86/busdma_bounce.c
View File

@ -66,6 +66,7 @@ enum {
BUS_DMA_COULD_BOUNCE = 0x01,
BUS_DMA_MIN_ALLOC_COMP = 0x02,
BUS_DMA_KMEM_ALLOC = 0x04,
BUS_DMA_FORCE_MAP = 0x08,
};
struct bounce_zone;
@ -301,7 +302,7 @@ bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
error = 0;
if (dmat->segments == NULL) {
dmat->segments = (bus_dma_segment_t *)malloc_domainset(
dmat->segments = malloc_domainset(
sizeof(bus_dma_segment_t) * dmat->common.nsegments,
M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT);
if (dmat->segments == NULL) {
@ -311,6 +312,19 @@ bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
}
}
if (dmat->bounce_flags & (BUS_DMA_COULD_BOUNCE | BUS_DMA_FORCE_MAP)) {
*mapp = malloc_domainset(sizeof(**mapp), M_DEVBUF,
DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
if (*mapp == NULL) {
CTR3(KTR_BUSDMA, "%s: tag %p error %d",
__func__, dmat, ENOMEM);
return (ENOMEM);
}
STAILQ_INIT(&(*mapp)->bpages);
} else {
*mapp = NULL;
}
/*
* Bouncing might be required if the driver asks for an active
* exclusion region, a data alignment that is stricter than 1, and/or
@ -318,23 +332,11 @@ bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
*/
if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
/* Must bounce */
if (dmat->bounce_zone == NULL) {
if ((error = alloc_bounce_zone(dmat)) != 0)
return (error);
}
if (dmat->bounce_zone == NULL &&
(error = alloc_bounce_zone(dmat)) != 0)
goto out;
bz = dmat->bounce_zone;
*mapp = (bus_dmamap_t)malloc_domainset(sizeof(**mapp), M_DEVBUF,
DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
if (*mapp == NULL) {
CTR3(KTR_BUSDMA, "%s: tag %p error %d",
__func__, dmat, ENOMEM);
return (ENOMEM);
}
/* Initialize the new map */
STAILQ_INIT(&((*mapp)->bpages));
/*
* Attempt to add pages to our pool on a per-instance
* basis up to a sane limit.
@ -361,11 +363,16 @@ bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
error = 0;
}
bz->map_count++;
}
out:
if (error == 0) {
dmat->map_count++;
} else {
free(*mapp, M_DEVBUF);
*mapp = NULL;
}
if (error == 0)
dmat->map_count++;
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
__func__, dmat, dmat->common.flags, error);
return (error);