ALSA: Replace snd_malloc_pages() and snd_free_pages() with standard helpers, take#2

snd_malloc_pages() and snd_free_pages() are merely thin wrappers of
the standard page allocator / free functions.  Even the arguments are
compatible with some standard helpers, so there is little merit of
keeping these wrappers.

This patch replaces the all existing callers of snd_malloc_pages() and
snd_free_pages() with the direct calls of the standard helper
functions.  In this version, we use a recently introduced one,
alloc_pages_exact(), which suits better than the old
snd_malloc_pages() implementation for our purposes.  Then we can avoid
the waste of pages by alignment to power-of-two.

Since alloc_pages_exact() does split pages, we need no longer
__GFP_COMP flag; or better to say, we must not pass __GFP_COMP to
alloc_pages_exact().  So the former unconditional addition of
__GFP_COMP flag in snd_malloc_pages() is dropped, as well as in most
other places.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 10 insertions, 57 deletions

diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index eb974235c92b..9f48e1d3a257 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -32,53 +32,6 @@
 
 /*
  *
- *  Generic memory allocators
- *
- */
-
-/**
- * snd_malloc_pages - allocate pages with the given size
- * @size: the size to allocate in bytes
- * @gfp_flags: the allocation conditions, GFP_XXX
- *
- * Allocates the physically contiguous pages with the given size.
- *
- * Return: The pointer of the buffer, or %NULL if no enough memory.
- */
-void *snd_malloc_pages(size_t size, gfp_t gfp_flags)
-{
-	int pg;
-
-	if (WARN_ON(!size))
-		return NULL;
-	if (WARN_ON(!gfp_flags))
-		return NULL;
-	gfp_flags |= __GFP_COMP;	/* compound page lets parts be mapped */
-	pg = get_order(size);
-	return (void *) __get_free_pages(gfp_flags, pg);
-}
-EXPORT_SYMBOL(snd_malloc_pages);
-
-/**
- * snd_free_pages - release the pages
- * @ptr: the buffer pointer to release
- * @size: the allocated buffer size
- *
- * Releases the buffer allocated via snd_malloc_pages().
- */
-void snd_free_pages(void *ptr, size_t size)
-{
-	int pg;
-
-	if (ptr == NULL)
-		return;
-	pg = get_order(size);
-	free_pages((unsigned long) ptr, pg);
-}
-EXPORT_SYMBOL(snd_free_pages);
-
-/*
- *
  *  Bus-specific memory allocators
  *
  */
@@ -190,8 +143,8 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size,
 	dmab->bytes = 0;
 	switch (type) {
 	case SNDRV_DMA_TYPE_CONTINUOUS:
-		dmab->area = snd_malloc_pages(size,
-					(__force gfp_t)(unsigned long)device);
+		dmab->area = alloc_pages_exact(size,
+					       (__force gfp_t)(unsigned long)device);
 		dmab->addr = 0;
 		break;
 #ifdef CONFIG_HAS_DMA
@@ -275,7 +228,7 @@ void snd_dma_free_pages(struct snd_dma_buffer *dmab)
 {
 	switch (dmab->dev.type) {
 	case SNDRV_DMA_TYPE_CONTINUOUS:
-		snd_free_pages(dmab->area, dmab->bytes);
+		free_pages_exact(dmab->area, dmab->bytes);
 		break;
 #ifdef CONFIG_HAS_DMA
 #ifdef CONFIG_GENERIC_ALLOCATOR
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 7b63aee124af..998e477522fd 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -959,22 +959,22 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 		return -ENOMEM;
 
 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
-	runtime->status = snd_malloc_pages(size, GFP_KERNEL);
+	runtime->status = alloc_pages_exact(size, GFP_KERNEL);
 	if (runtime->status == NULL) {
 		kfree(runtime);
 		return -ENOMEM;
 	}
-	memset((void*)runtime->status, 0, size);
+	memset(runtime->status, 0, size);
 
 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
-	runtime->control = snd_malloc_pages(size, GFP_KERNEL);
+	runtime->control = alloc_pages_exact(size, GFP_KERNEL);
 	if (runtime->control == NULL) {
-		snd_free_pages((void*)runtime->status,
+		free_pages_exact(runtime->status,
 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 		kfree(runtime);
 		return -ENOMEM;
 	}
-	memset((void*)runtime->control, 0, size);
+	memset(runtime->control, 0, size);
 
 	init_waitqueue_head(&runtime->sleep);
 	init_waitqueue_head(&runtime->tsleep);
@@ -1000,9 +1000,9 @@ void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
 	runtime = substream->runtime;
 	if (runtime->private_free != NULL)
 		runtime->private_free(runtime);
-	snd_free_pages((void*)runtime->status,
+	free_pages_exact(runtime->status,
 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
-	snd_free_pages((void*)runtime->control,
+	free_pages_exact(runtime->control,
 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
 	kfree(runtime->hw_constraints.rules);
 	/* Avoid concurrent access to runtime via PCM timer interface */