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-rw-r--r--sys/arm/arm/busdma_machdep-v6.c108
1 files changed, 40 insertions, 68 deletions
diff --git a/sys/arm/arm/busdma_machdep-v6.c b/sys/arm/arm/busdma_machdep-v6.c
index 4c308d953f46..1e460a02b255 100644
--- a/sys/arm/arm/busdma_machdep-v6.c
+++ b/sys/arm/arm/busdma_machdep-v6.c
@@ -64,6 +64,7 @@ __FBSDID("$FreeBSD$");
#include <machine/md_var.h>
#define MAX_BPAGES 64
+#define MAX_DMA_SEGMENTS 4096
#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)
@@ -96,15 +97,6 @@ struct bus_dma_tag {
*/
struct arm32_dma_range *ranges;
int _nranges;
- /*
- * Most tags need one or two segments, and can use the local tagsegs
- * array. For tags with a larger limit, we'll allocate a bigger array
- * on first use.
- */
- bus_dma_segment_t *segments;
- bus_dma_segment_t tagsegs[2];
-
-
};
struct bounce_page {
@@ -165,6 +157,7 @@ struct bus_dmamap {
#define DMAMAP_DMAMEM_ALLOC (1 << 1)
#define DMAMAP_MBUF (1 << 2)
STAILQ_ENTRY(bus_dmamap) links;
+ bus_dma_segment_t *segments;
int sync_count;
struct sync_list slist[];
};
@@ -476,18 +469,6 @@ bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
newtag->lockfunc = dflt_lock;
newtag->lockfuncarg = NULL;
}
- /*
- * If all the segments we need fit into the local tagsegs array, set the
- * pointer now. Otherwise NULL the pointer and an array of segments
- * will be allocated later, on first use. We don't pre-allocate now
- * because some tags exist just to pass contraints to children in the
- * device hierarchy, and they tend to use BUS_SPACE_UNRESTRICTED and we
- * sure don't want to try to allocate an array for that.
- */
- if (newtag->nsegments <= nitems(newtag->tagsegs))
- newtag->segments = newtag->tagsegs;
- else
- newtag->segments = NULL;
/* Take into account any restrictions imposed by our parent tag */
if (parent != NULL) {
@@ -584,9 +565,6 @@ bus_dma_tag_destroy(bus_dma_tag_t dmat)
parent = dmat->parent;
atomic_subtract_int(&dmat->ref_count, 1);
if (dmat->ref_count == 0) {
- if (dmat->segments != NULL &&
- dmat->segments != dmat->tagsegs)
- free(dmat->segments, M_DEVBUF);
free(dmat, M_DEVBUF);
/*
* Last reference count, so
@@ -643,6 +621,31 @@ static int allocate_bz_and_pages(bus_dma_tag_t dmat, bus_dmamap_t mapp)
return (0);
}
+static bus_dmamap_t
+allocate_map(bus_dma_tag_t dmat, int mflags)
+{
+ int mapsize, segsize;
+ bus_dmamap_t map;
+
+ /*
+ * Allocate the map. The map structure ends with an embedded
+ * variable-sized array of sync_list structures. Following that
+ * we allocate enough extra space to hold the array of bus_dma_segments.
+ */
+ KASSERT(dmat->nsegments <= MAX_DMA_SEGMENTS,
+ ("cannot allocate %u dma segments (max is %u)",
+ dmat->nsegments, MAX_DMA_SEGMENTS));
+ segsize = sizeof(struct bus_dma_segment) * dmat->nsegments;
+ mapsize = sizeof(*map) + sizeof(struct sync_list) * dmat->nsegments;
+ map = malloc(mapsize + segsize, M_DEVBUF, mflags | M_ZERO);
+ if (map == NULL) {
+ CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, ENOMEM);
+ return (NULL);
+ }
+ map->segments = (bus_dma_segment_t *)((uintptr_t)map + mapsize);
+ return (map);
+}
+
/*
* Allocate a handle for mapping from kva/uva/physical
* address space into bus device space.
@@ -651,33 +654,20 @@ int
bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
{
bus_dmamap_t map;
- int mapsize;
int error = 0;
- mapsize = sizeof(*map) + (sizeof(struct sync_list) * dmat->nsegments);
- *mapp = map = malloc(mapsize, M_DEVBUF, M_NOWAIT | M_ZERO);
+ *mapp = map = allocate_map(dmat, M_NOWAIT);
if (map == NULL) {
CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, ENOMEM);
return (ENOMEM);
}
- map->sync_count = 0;
- if (dmat->segments == NULL) {
- dmat->segments = (bus_dma_segment_t *)malloc(
- sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
- M_NOWAIT);
- if (dmat->segments == NULL) {
- CTR3(KTR_BUSDMA, "%s: tag %p error %d",
- __func__, dmat, ENOMEM);
- free(map, M_DEVBUF);
- *mapp = NULL;
- return (ENOMEM);
- }
- }
/*
- * Bouncing might be required if the driver asks for an active
- * exclusion region, a data alignment that is stricter than 1, and/or
- * an active address boundary.
+ * Bouncing might be required if the driver asks for an exclusion
+ * region, a data alignment that is stricter than 1, or DMA that begins
+ * or ends with a partial cacheline. Whether bouncing will actually
+ * happen can't be known until mapping time, but we need to pre-allocate
+ * resources now because we might not be allowed to at mapping time.
*/
error = allocate_bz_and_pages(dmat, map);
if (error != 0) {
@@ -723,41 +713,23 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
bus_dmamap_t map;
vm_memattr_t memattr;
int mflags;
- int mapsize;
- int error;
if (flags & BUS_DMA_NOWAIT)
mflags = M_NOWAIT;
else
mflags = M_WAITOK;
+ if (flags & BUS_DMA_ZERO)
+ mflags |= M_ZERO;
- /* ARM non-snooping caches need a map for the VA cache sync structure */
-
- mapsize = sizeof(*map) + (sizeof(struct sync_list) * dmat->nsegments);
- *mapp = map = malloc(mapsize, M_DEVBUF, M_NOWAIT | M_ZERO);
+ *mapp = map = allocate_map(dmat, mflags);
if (map == NULL) {
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
__func__, dmat, dmat->flags, ENOMEM);
return (ENOMEM);
}
map->flags = DMAMAP_DMAMEM_ALLOC;
- map->sync_count = 0;
-
- if (dmat->segments == NULL) {
- dmat->segments = (bus_dma_segment_t *)malloc(
- sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
- mflags);
- if (dmat->segments == NULL) {
- CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
- __func__, dmat, dmat->flags, ENOMEM);
- free(map, M_DEVBUF);
- *mapp = NULL;
- return (ENOMEM);
- }
- }
- if (flags & BUS_DMA_ZERO)
- mflags |= M_ZERO;
+ /* Choose a busdma buffer allocator based on memory type flags. */
if (flags & BUS_DMA_COHERENT) {
memattr = VM_MEMATTR_UNCACHEABLE;
ba = coherent_allocator;
@@ -1016,7 +988,7 @@ _bus_dmamap_load_phys(bus_dma_tag_t dmat,
int error;
if (segs == NULL)
- segs = dmat->segments;
+ segs = map->segments;
if (might_bounce(dmat, map, buflen, buflen)) {
_bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
@@ -1084,7 +1056,7 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
int error;
if (segs == NULL)
- segs = dmat->segments;
+ segs = map->segments;
if (flags & BUS_DMA_LOAD_MBUF)
map->flags |= DMAMAP_MBUF;
@@ -1179,7 +1151,7 @@ _bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
{
if (segs == NULL)
- segs = dmat->segments;
+ segs = map->segments;
return (segs);
}
generated by cgit v1.2.3 (git 2.25.1) at 2023-09-29 11:40:38 +0000