[alsa-devel] [PATCH] ALSA: Replace snd_malloc_pages() and snd_free_pages() with standard helpers

Takashi Iwai tiwai at suse.de
Fri Nov 23 21:35:26 CET 2018


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.  Then we can avoid the waste of
pages by alignment to power-of-two.

Also, the __GFP_COMP flag that has been always added in the old
implementation is dropped for most of callers now.  The only one that
may still need it is the PCM buffer allocation which can be quite
large.  The rest are single page allocations, so no sense to keep that
flag.

With these conversions, snd_malloc_pages() and snd_free_pages() are
dropped altogether from the whole tree.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 include/sound/memalloc.h        |  4 ---
 sound/core/memalloc.c           | 54 +++------------------------------
 sound/core/pcm.c                | 14 ++++-----
 sound/usb/usx2y/usX2Yhwdep.c    |  3 +-
 sound/usb/usx2y/usbusx2y.c      |  3 +-
 sound/usb/usx2y/usx2yhwdeppcm.c |  6 ++--
 6 files changed, 19 insertions(+), 65 deletions(-)

diff --git a/include/sound/memalloc.h b/include/sound/memalloc.h
index af3fa577fa06..c56cb2871368 100644
--- a/include/sound/memalloc.h
+++ b/include/sound/memalloc.h
@@ -152,9 +152,5 @@ int snd_dma_alloc_pages_fallback(int type, struct device *dev, size_t size,
                                  struct snd_dma_buffer *dmab);
 void snd_dma_free_pages(struct snd_dma_buffer *dmab);
 
-/* basic memory allocation functions */
-void *snd_malloc_pages(size_t size, gfp_t gfp_flags);
-void snd_free_pages(void *ptr, size_t size);
-
 #endif /* __SOUND_MEMALLOC_H */
 
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index 59a4adc286ed..d12bf811e751 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -30,53 +30,6 @@
 #endif
 #include <sound/memalloc.h>
 
-/*
- *
- *  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
@@ -188,8 +141,9 @@ 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 |
+					       __GFP_COMP);
 		dmab->addr = 0;
 		break;
 #ifdef CONFIG_HAS_DMA
@@ -273,7 +227,7 @@ 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 fdb9b92fc8d6..1c0ecb22b1f4 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -1004,22 +1004,22 @@ 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);
@@ -1045,9 +1045,9 @@ 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 */
diff --git a/sound/usb/usx2y/usX2Yhwdep.c b/sound/usb/usx2y/usX2Yhwdep.c
index c1dd9a7b48df..bfe1108416cf 100644
--- a/sound/usb/usx2y/usX2Yhwdep.c
+++ b/sound/usb/usx2y/usX2Yhwdep.c
@@ -75,7 +75,8 @@ static int snd_us428ctls_mmap(struct snd_hwdep * hw, struct file *filp, struct v
 
 	if (!us428->us428ctls_sharedmem) {
 		init_waitqueue_head(&us428->us428ctls_wait_queue_head);
-		if(!(us428->us428ctls_sharedmem = snd_malloc_pages(sizeof(struct us428ctls_sharedmem), GFP_KERNEL)))
+		us428->us428ctls_sharedmem = alloc_pages_exact(sizeof(struct us428ctls_sharedmem), GFP_KERNEL);
+		if (!us428->us428ctls_sharedmem)
 			return -ENOMEM;
 		memset(us428->us428ctls_sharedmem, -1, sizeof(struct us428ctls_sharedmem));
 		us428->us428ctls_sharedmem->CtlSnapShotLast = -2;
diff --git a/sound/usb/usx2y/usbusx2y.c b/sound/usb/usx2y/usbusx2y.c
index da4a5a541512..9f7bbed2c0f0 100644
--- a/sound/usb/usx2y/usbusx2y.c
+++ b/sound/usb/usx2y/usbusx2y.c
@@ -437,7 +437,8 @@ static void snd_usX2Y_card_private_free(struct snd_card *card)
 	kfree(usX2Y(card)->In04Buf);
 	usb_free_urb(usX2Y(card)->In04urb);
 	if (usX2Y(card)->us428ctls_sharedmem)
-		snd_free_pages(usX2Y(card)->us428ctls_sharedmem, sizeof(*usX2Y(card)->us428ctls_sharedmem));
+		free_pages_exact(usX2Y(card)->us428ctls_sharedmem,
+				 sizeof(*usX2Y(card)->us428ctls_sharedmem));
 	if (usX2Y(card)->card_index >= 0  &&  usX2Y(card)->card_index < SNDRV_CARDS)
 		snd_usX2Y_card_used[usX2Y(card)->card_index] = 0;
 }
diff --git a/sound/usb/usx2y/usx2yhwdeppcm.c b/sound/usb/usx2y/usx2yhwdeppcm.c
index 4fd9276b8e50..4453c2b911d0 100644
--- a/sound/usb/usx2y/usx2yhwdeppcm.c
+++ b/sound/usb/usx2y/usx2yhwdeppcm.c
@@ -488,7 +488,9 @@ static int snd_usX2Y_usbpcm_prepare(struct snd_pcm_substream *substream)
 	snd_printdd("snd_usX2Y_pcm_prepare(%p)\n", substream);
 
 	if (NULL == usX2Y->hwdep_pcm_shm) {
-		if (NULL == (usX2Y->hwdep_pcm_shm = snd_malloc_pages(sizeof(struct snd_usX2Y_hwdep_pcm_shm), GFP_KERNEL)))
+		usX2Y->hwdep_pcm_shm = alloc_pages_exact(sizeof(struct snd_usX2Y_hwdep_pcm_shm),
+							 GFP_KERNEL);
+		if (!usX2Y->hwdep_pcm_shm)
 			return -ENOMEM;
 		memset(usX2Y->hwdep_pcm_shm, 0, sizeof(struct snd_usX2Y_hwdep_pcm_shm));
 	}
@@ -700,7 +702,7 @@ static void snd_usX2Y_hwdep_pcm_private_free(struct snd_hwdep *hwdep)
 {
 	struct usX2Ydev *usX2Y = hwdep->private_data;
 	if (NULL != usX2Y->hwdep_pcm_shm)
-		snd_free_pages(usX2Y->hwdep_pcm_shm, sizeof(struct snd_usX2Y_hwdep_pcm_shm));
+		free_pages_exact(usX2Y->hwdep_pcm_shm, sizeof(struct snd_usX2Y_hwdep_pcm_shm));
 }
 
 
-- 
2.19.1



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