Honor maxsegsz of less than a page size in a DMA tag. Previously it

used to return PAGE_SIZE without respect to restrictions of a DMA tag.
This affected all of the busdma load functions that use
_bus_dmamap_loader_buffer() as their back-end.

Reviewed by:	scottl

6 files changed, 12 insertions, 0 deletions

diff --git a/sys/amd64/amd64/busdma_machdep.c b/sys/amd64/amd64/busdma_machdep.c
index a2b19d6..59495bf 100644
--- a/sys/amd64/amd64/busdma_machdep.c
+++ b/sys/amd64/amd64/busdma_machdep.c
@@ -649,6 +649,8 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 		 * Compute the segment size, and adjust counts.
 		 */
 		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
+		if (sgsize > dmat->maxsegsz)
+			sgsize = dmat->maxsegsz;
 		if (buflen < sgsize)
 			sgsize = buflen;
 
diff --git a/sys/arm/arm/busdma_machdep.c b/sys/arm/arm/busdma_machdep.c
index f8d2725..b3ee458 100644
--- a/sys/arm/arm/busdma_machdep.c
+++ b/sys/arm/arm/busdma_machdep.c
@@ -799,6 +799,8 @@ bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
 		 * Compute the segment size, and adjust counts.
 		 */
 		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
+		if (sgsize > dmat->maxsegsz)
+			sgsize = dmat->maxsegsz;
 		if (buflen < sgsize)
 			sgsize = buflen;
 
diff --git a/sys/i386/i386/busdma_machdep.c b/sys/i386/i386/busdma_machdep.c
index 813e9ca..5d7c9cd 100644
--- a/sys/i386/i386/busdma_machdep.c
+++ b/sys/i386/i386/busdma_machdep.c
@@ -674,6 +674,8 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 		 * Compute the segment size, and adjust counts.
 		 */
 		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
+		if (sgsize > dmat->maxsegsz)
+			sgsize = dmat->maxsegsz;
 		if (buflen < sgsize)
 			sgsize = buflen;
 
diff --git a/sys/ia64/ia64/busdma_machdep.c b/sys/ia64/ia64/busdma_machdep.c
index 34cc252..5ef2e53 100644
--- a/sys/ia64/ia64/busdma_machdep.c
+++ b/sys/ia64/ia64/busdma_machdep.c
@@ -578,6 +578,8 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 		 * Compute the segment size, and adjust counts.
 		 */
 		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
+		if (sgsize > dmat->maxsegsz)
+			sgsize = dmat->maxsegsz;
 		if (buflen < sgsize)
 			sgsize = buflen;
 
diff --git a/sys/sparc64/sparc64/bus_machdep.c b/sys/sparc64/sparc64/bus_machdep.c
index 165e350..0d1e926 100644
--- a/sys/sparc64/sparc64/bus_machdep.c
+++ b/sys/sparc64/sparc64/bus_machdep.c
@@ -372,6 +372,8 @@ _nexus_dmamap_load_buffer(bus_dma_tag_t dmat, void *buf, bus_size_t buflen,
 		 * Compute the segment size, and adjust counts.
 		 */
 		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
+		if (sgsize > dmat->dt_maxsegsz)
+			sgsize = dmat->dt_maxsegsz;
 		if (buflen < sgsize)
 			sgsize = buflen;
 
diff --git a/sys/sun4v/sun4v/bus_machdep.c b/sys/sun4v/sun4v/bus_machdep.c
index 06a7f35..0c76fee 100644
--- a/sys/sun4v/sun4v/bus_machdep.c
+++ b/sys/sun4v/sun4v/bus_machdep.c
@@ -381,6 +381,8 @@ _nexus_dmamap_load_buffer(bus_dma_tag_t dmat, void *buf, bus_size_t buflen,
 		 * Compute the segment size, and adjust counts.
 		 */
 		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
+		if (sgsize > dmat->dt_maxsegsz)
+			sgsize = dmat->dt_maxsegsz;
 		if (buflen < sgsize)
 			sgsize = buflen;