[patch 13/18] alsa: nopage

[npiggin@suse.de]

[-- Attachment #1: alsa-nopage.patch --]
[-- Type: text/plain, Size: 4171 bytes --]

Convert ALSA from nopage to fault.
Switch from OOM to SIGBUS if the resource is not available.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: perex@perex.cz
Cc: tiwai@suse.de
Cc: alsa-devel@alsa-project.org
Cc: linux-kernel@vger.kernel.org
---
 sound/core/pcm_native.c |   59 ++++++++++++++++++++----------------------------
 1 file changed, 25 insertions(+), 34 deletions(-)

Index: linux-2.6/sound/core/pcm_native.c
===================================================================
--- linux-2.6.orig/sound/core/pcm_native.c
+++ linux-2.6/sound/core/pcm_native.c
@@ -3018,26 +3018,23 @@ static unsigned int snd_pcm_capture_poll
 /*
  * mmap status record
  */
-static struct page * snd_pcm_mmap_status_nopage(struct vm_area_struct *area,
-						unsigned long address, int *type)
+static int snd_pcm_mmap_status_fault(struct vm_area_struct *area,
+						struct vm_fault *vmf)
 {
 	struct snd_pcm_substream *substream = area->vm_private_data;
 	struct snd_pcm_runtime *runtime;
-	struct page * page;
 	
 	if (substream == NULL)
-		return NOPAGE_SIGBUS;
+		return VM_FAULT_SIGBUS;
 	runtime = substream->runtime;
-	page = virt_to_page(runtime->status);
-	get_page(page);
-	if (type)
-		*type = VM_FAULT_MINOR;
-	return page;
+	vmf->page = virt_to_page(runtime->status);
+	get_page(vmf->page);
+	return 0;
 }
 
 static struct vm_operations_struct snd_pcm_vm_ops_status =
 {
-	.nopage =	snd_pcm_mmap_status_nopage,
+	.fault =	snd_pcm_mmap_status_fault,
 };
 
 static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file *file,
@@ -3061,26 +3058,23 @@ static int snd_pcm_mmap_status(struct sn
 /*
  * mmap control record
  */
-static struct page * snd_pcm_mmap_control_nopage(struct vm_area_struct *area,
-						 unsigned long address, int *type)
+static int snd_pcm_mmap_control_fault(struct vm_area_struct *area,
+						struct vm_fault *vmf)
 {
 	struct snd_pcm_substream *substream = area->vm_private_data;
 	struct snd_pcm_runtime *runtime;
-	struct page * page;
 	
 	if (substream == NULL)
-		return NOPAGE_SIGBUS;
+		return VM_FAULT_SIGBUS;
 	runtime = substream->runtime;
-	page = virt_to_page(runtime->control);
-	get_page(page);
-	if (type)
-		*type = VM_FAULT_MINOR;
-	return page;
+	vmf->page = virt_to_page(runtime->control);
+	get_page(vmf->page);
+	return 0;
 }
 
 static struct vm_operations_struct snd_pcm_vm_ops_control =
 {
-	.nopage =	snd_pcm_mmap_control_nopage,
+	.fault =	snd_pcm_mmap_control_fault,
 };
 
 static int snd_pcm_mmap_control(struct snd_pcm_substream *substream, struct file *file,
@@ -3117,10 +3111,10 @@ static int snd_pcm_mmap_control(struct s
 #endif /* coherent mmap */
 
 /*
- * nopage callback for mmapping a RAM page
+ * fault callback for mmapping a RAM page
  */
-static struct page *snd_pcm_mmap_data_nopage(struct vm_area_struct *area,
-					     unsigned long address, int *type)
+static int snd_pcm_mmap_data_fault(struct vm_area_struct *area,
+						struct vm_fault *vmf)
 {
 	struct snd_pcm_substream *substream = area->vm_private_data;
 	struct snd_pcm_runtime *runtime;
@@ -3130,33 +3124,30 @@ static struct page *snd_pcm_mmap_data_no
 	size_t dma_bytes;
 	
 	if (substream == NULL)
-		return NOPAGE_SIGBUS;
+		return VM_FAULT_SIGBUS;
 	runtime = substream->runtime;
-	offset = area->vm_pgoff << PAGE_SHIFT;
-	offset += address - area->vm_start;
-	snd_assert((offset % PAGE_SIZE) == 0, return NOPAGE_SIGBUS);
+	offset = vmf->pgoff << PAGE_SHIFT;
 	dma_bytes = PAGE_ALIGN(runtime->dma_bytes);
 	if (offset > dma_bytes - PAGE_SIZE)
-		return NOPAGE_SIGBUS;
+		return VM_FAULT_SIGBUS;
 	if (substream->ops->page) {
 		page = substream->ops->page(substream, offset);
-		if (! page)
-			return NOPAGE_OOM; /* XXX: is this really due to OOM? */
+		if (!page)
+			return VM_FAULT_SIGBUS;
 	} else {
 		vaddr = runtime->dma_area + offset;
 		page = virt_to_page(vaddr);
 	}
 	get_page(page);
-	if (type)
-		*type = VM_FAULT_MINOR;
-	return page;
+	vmf->page = page;
+	return 0;
 }
 
 static struct vm_operations_struct snd_pcm_vm_ops_data =
 {
 	.open =		snd_pcm_mmap_data_open,
 	.close =	snd_pcm_mmap_data_close,
-	.nopage =	snd_pcm_mmap_data_nopage,
+	.fault =	snd_pcm_mmap_data_fault,
 };
 
 /*

--