amd64/133592: [busdma] [patch] busdma incorrectly calculates bounce buffer requirements for userspace buffers

[Kostik Belousov]

On Sun, Apr 12, 2009 at 03:20:06PM +0000, Scott Long wrote:
> The following reply was made to PR amd64/133592; it has been noted by GNATS.
> 
> From: Scott Long <scottl at samsco.org>
> To: bug-followup at FreeBSD.org, jason.harmening at gmail.com
> Cc:  
> Subject: Re: amd64/133592: [busdma] [patch] busdma incorrectly calculates
>  bounce buffer requirements for userspace buffers
> Date: Sun, 12 Apr 2009 08:53:47 -0600
> 
>  You're right, it's definitely a problem.  The patch looks correct, feel
>  free to commit to i386, amd64, and ia64.  Arm needs a similar fix, but
>  the code looks to be somewhat different.

Below is updated patch. It was compile-tested on all affected arches.
Scott, any notes ?

diff --git a/sys/amd64/amd64/busdma_machdep.c b/sys/amd64/amd64/busdma_machdep.c
index c50fcc3..de4717c 100644
--- a/sys/amd64/amd64/busdma_machdep.c
+++ b/sys/amd64/amd64/busdma_machdep.c
@@ -606,7 +606,10 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 		vendaddr = (vm_offset_t)buf + buflen;
 
 		while (vaddr < vendaddr) {
-			paddr = pmap_kextract(vaddr);
+			if (pmap)
+				paddr = pmap_extract(pmap, vaddr);
+			else
+				paddr = pmap_kextract(vaddr);
 			if (run_filter(dmat, paddr) != 0)
 				map->pagesneeded++;
 			vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
diff --git a/sys/arm/arm/busdma_machdep.c b/sys/arm/arm/busdma_machdep.c
index a738172..153d83f 100644
--- a/sys/arm/arm/busdma_machdep.c
+++ b/sys/arm/arm/busdma_machdep.c
@@ -669,8 +669,8 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 }
 
 static int
-_bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
-			bus_size_t buflen, int flags)
+_bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
+    void *buf, bus_size_t buflen, int flags)
 {
 	vm_offset_t vaddr;
 	vm_offset_t vendaddr;
@@ -689,7 +689,10 @@ _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 		vendaddr = (vm_offset_t)buf + buflen;
 
 		while (vaddr < vendaddr) {
-			paddr = pmap_kextract(vaddr);
+			if (pmap != NULL)
+				paddr = pmap_extract(pmap, vaddr);
+			else
+				paddr = pmap_kextract(vaddr);
 			if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 			    run_filter(dmat, paddr) != 0)
 				map->pagesneeded++;
@@ -745,7 +748,8 @@ bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
 	bmask = ~(dmat->boundary - 1);
 
 	if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
-		error = _bus_dmamap_count_pages(dmat, map, buf, buflen, flags);
+		error = _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen,
+		    flags);
 		if (error)
 			return (error);
 	}
diff --git a/sys/i386/i386/busdma_machdep.c b/sys/i386/i386/busdma_machdep.c
index d4aa9b5..cf0ac51 100644
--- a/sys/i386/i386/busdma_machdep.c
+++ b/sys/i386/i386/busdma_machdep.c
@@ -142,8 +142,8 @@ static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 				   vm_offset_t vaddr, bus_size_t size);
 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
-int _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
-			    bus_size_t buflen, int flags);
+int _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
+    void *buf, bus_size_t buflen, int flags);
 
 #ifdef XEN
 #undef pmap_kextract
@@ -577,8 +577,8 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 }
 
 int
-_bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
-			bus_size_t buflen, int flags)
+_bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
+    void *buf, bus_size_t buflen, int flags)
 {
 	vm_offset_t vaddr;
 	vm_offset_t vendaddr;
@@ -598,7 +598,10 @@ _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 		vendaddr = (vm_offset_t)buf + buflen;
 
 		while (vaddr < vendaddr) {
-			paddr = pmap_kextract(vaddr);
+			if (pmap)
+				paddr = pmap_extract(pmap, vaddr);
+			else
+				paddr = pmap_kextract(vaddr);
 			if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 			    run_filter(dmat, paddr) != 0) {
 				map->pagesneeded++;
@@ -660,7 +663,7 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 		map = &nobounce_dmamap;
 
 	if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
-		error = _bus_dmamap_count_pages(dmat, map, buf, buflen, flags);
+		error = _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 		if (error)
 			return (error);
 	}
diff --git a/sys/ia64/ia64/busdma_machdep.c b/sys/ia64/ia64/busdma_machdep.c
index 659db52..609a8a9 100644
--- a/sys/ia64/ia64/busdma_machdep.c
+++ b/sys/ia64/ia64/busdma_machdep.c
@@ -527,7 +527,10 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 		vendaddr = (vm_offset_t)buf + buflen;
 
 		while (vaddr < vendaddr) {
-			paddr = pmap_kextract(vaddr);
+			if (pmap != NULL)
+				paddr = pmap_extract(pmap, vaddr);
+			else
+				paddr = pmap_kextract(vaddr);
 			if (run_filter(dmat, paddr, 0) != 0)
 				map->pagesneeded++;
 			vaddr += PAGE_SIZE;
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