1 files changed, 81 insertions, 18 deletions

diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
index 9aea1d6fb054..b961a30c2a22 100644
--- a/sound/core/pcm_memory.c
+++ b/sound/core/pcm_memory.c
@@ -26,6 +26,67 @@ MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA m
 
 static const size_t snd_minimum_buffer = 16384;
 
+static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
+module_param(max_alloc_per_card, ulong, 0644);
+MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
+
+static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
+{
+	card->total_pcm_alloc_bytes += bytes;
+}
+
+static void update_allocated_size(struct snd_card *card, ssize_t bytes)
+{
+	mutex_lock(&card->memory_mutex);
+	__update_allocated_size(card, bytes);
+	mutex_unlock(&card->memory_mutex);
+}
+
+static void decrease_allocated_size(struct snd_card *card, size_t bytes)
+{
+	mutex_lock(&card->memory_mutex);
+	WARN_ON(card->total_pcm_alloc_bytes < bytes);
+	__update_allocated_size(card, -(ssize_t)bytes);
+	mutex_unlock(&card->memory_mutex);
+}
+
+static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
+			  size_t size, struct snd_dma_buffer *dmab)
+{
+	int err;
+
+	/* check and reserve the requested size */
+	mutex_lock(&card->memory_mutex);
+	if (max_alloc_per_card &&
+	    card->total_pcm_alloc_bytes + size > max_alloc_per_card) {
+		mutex_unlock(&card->memory_mutex);
+		return -ENOMEM;
+	}
+	__update_allocated_size(card, size);
+	mutex_unlock(&card->memory_mutex);
+
+	err = snd_dma_alloc_pages(type, dev, size, dmab);
+	if (!err) {
+		/* the actual allocation size might be bigger than requested,
+		 * and we need to correct the account
+		 */
+		if (dmab->bytes != size)
+			update_allocated_size(card, dmab->bytes - size);
+	} else {
+		/* take back on allocation failure */
+		decrease_allocated_size(card, size);
+	}
+	return err;
+}
+
+static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
+{
+	if (!dmab->area)
+		return;
+	decrease_allocated_size(card, dmab->bytes);
+	snd_dma_free_pages(dmab);
+	dmab->area = NULL;
+}
 
 /*
  * try to allocate as the large pages as possible.
@@ -36,16 +97,15 @@ static const size_t snd_minimum_buffer = 16384;
 static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
 {
 	struct snd_dma_buffer *dmab = &substream->dma_buffer;
+	struct snd_card *card = substream->pcm->card;
 	size_t orig_size = size;
 	int err;
 
 	do {
-		if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
-					       size, dmab)) < 0) {
-			if (err != -ENOMEM)
-				return err; /* fatal error */
-		} else
-			return 0;
+		err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
+				     size, dmab);
+		if (err != -ENOMEM)
+			return err;
 		size >>= 1;
 	} while (size >= snd_minimum_buffer);
 	dmab->bytes = 0; /* tell error */
@@ -61,10 +121,7 @@ static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t siz
  */
 static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
 {
-	if (substream->dma_buffer.area == NULL)
-		return;
-	snd_dma_free_pages(&substream->dma_buffer);
-	substream->dma_buffer.area = NULL;
+	do_free_pages(substream->pcm->card, &substream->dma_buffer);
 }
 
 /**
@@ -129,6 +186,7 @@ static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
 					       struct snd_info_buffer *buffer)
 {
 	struct snd_pcm_substream *substream = entry->private_data;
+	struct snd_card *card = substream->pcm->card;
 	char line[64], str[64];
 	size_t size;
 	struct snd_dma_buffer new_dmab;
@@ -150,9 +208,10 @@ static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
 		memset(&new_dmab, 0, sizeof(new_dmab));
 		new_dmab.dev = substream->dma_buffer.dev;
 		if (size > 0) {
-			if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
-						substream->dma_buffer.dev.dev,
-						size, &new_dmab) < 0) {
+			if (do_alloc_pages(card,
+					   substream->dma_buffer.dev.type,
+					   substream->dma_buffer.dev.dev,
+					   size, &new_dmab) < 0) {
 				buffer->error = -ENOMEM;
 				goto unlock;
 			}
@@ -161,7 +220,7 @@ static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
 			substream->buffer_bytes_max = UINT_MAX;
 		}
 		if (substream->dma_buffer.area)
-			snd_dma_free_pages(&substream->dma_buffer);
+			do_free_pages(card, &substream->dma_buffer);
 		substream->dma_buffer = new_dmab;
 	} else {
 		buffer->error = -EINVAL;
@@ -289,6 +348,7 @@ EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
  */
 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
 {
+	struct snd_card *card = substream->pcm->card;
 	struct snd_pcm_runtime *runtime;
 	struct snd_dma_buffer *dmab = NULL;
 
@@ -317,9 +377,10 @@ int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
 		if (! dmab)
 			return -ENOMEM;
 		dmab->dev = substream->dma_buffer.dev;
-		if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
-					substream->dma_buffer.dev.dev,
-					size, dmab) < 0) {
+		if (do_alloc_pages(card,
+				   substream->dma_buffer.dev.type,
+				   substream->dma_buffer.dev.dev,
+				   size, dmab) < 0) {
 			kfree(dmab);
 			return -ENOMEM;
 		}
@@ -348,8 +409,10 @@ int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
 	if (runtime->dma_area == NULL)
 		return 0;
 	if (runtime->dma_buffer_p != &substream->dma_buffer) {
+		struct snd_card *card = substream->pcm->card;
+
 		/* it's a newly allocated buffer.  release it now. */
-		snd_dma_free_pages(runtime->dma_buffer_p);
+		do_free_pages(card, runtime->dma_buffer_p);
 		kfree(runtime->dma_buffer_p);
 	}
 	snd_pcm_set_runtime_buffer(substream, NULL);