Teach bus_dmamem_free() about contigfree(). This is a bit of a hack,

but it's better than the buggy behavior we have now. If we contigmalloc()
buffers in bus_dmamem_alloc(), then we must configfree() them in
bus_dmamem_free(). Trying to free() them is wrong, and will cause
a panic (at least, it does on the alpha.)

I tripped over this when trying to kldunload my busdma-ified if_rl
driver.

1 files changed, 4 insertions, 1 deletions

diff --git a/sys/alpha/alpha/busdma_machdep.c b/sys/alpha/alpha/busdma_machdep.c
index ea984c3..7125636 100644
--- a/sys/alpha/alpha/busdma_machdep.c
+++ b/sys/alpha/alpha/busdma_machdep.c
@@ -384,7 +384,10 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 	 */
 	if (map != &nobounce_dmamap)
 		panic("bus_dmamem_free: Invalid map freed\n");
-	free(vaddr, M_DEVBUF);
+	if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem)) {
+		free(vaddr, M_DEVBUF);
+	else
+		contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 }
 
 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)