1 files changed, 111 insertions, 0 deletions
diff --git a/sound/core/sgbuf.c b/sound/core/sgbuf.c
new file mode 100644
index 000000000000..74745da9deb6
--- /dev/null
+++ b/sound/core/sgbuf.c
@@ -0,0 +1,111 @@
+/*
+ * Scatter-Gather buffer
+ *
+ *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <sound/memalloc.h>
+
+
+/* table entries are align to 32 */
+#define SGBUF_TBL_ALIGN		32
+#define sgbuf_align_table(tbl)	((((tbl) + SGBUF_TBL_ALIGN - 1) / SGBUF_TBL_ALIGN) * SGBUF_TBL_ALIGN)
+
+int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab)
+{
+	struct snd_sg_buf *sgbuf = dmab->private_data;
+	struct snd_dma_buffer tmpb;
+	int i;
+
+	if (! sgbuf)
+		return -EINVAL;
+
+	tmpb.dev.type = SNDRV_DMA_TYPE_DEV;
+	tmpb.dev.dev = sgbuf->dev;
+	for (i = 0; i < sgbuf->pages; i++) {
+		tmpb.area = sgbuf->table[i].buf;
+		tmpb.addr = sgbuf->table[i].addr;
+		tmpb.bytes = PAGE_SIZE;
+		snd_dma_free_pages(&tmpb);
+	}
+	if (dmab->area)
+		vunmap(dmab->area);
+	dmab->area = NULL;
+
+	kfree(sgbuf->table);
+	kfree(sgbuf->page_table);
+	kfree(sgbuf);
+	dmab->private_data = NULL;
+	
+	return 0;
+}
+
+void *snd_malloc_sgbuf_pages(struct device *device,
+			     size_t size, struct snd_dma_buffer *dmab,
+			     size_t *res_size)
+{
+	struct snd_sg_buf *sgbuf;
+	unsigned int i, pages;
+	struct snd_dma_buffer tmpb;
+
+	dmab->area = NULL;
+	dmab->addr = 0;
+	dmab->private_data = sgbuf = kmalloc(sizeof(*sgbuf), GFP_KERNEL);
+	if (! sgbuf)
+		return NULL;
+	memset(sgbuf, 0, sizeof(*sgbuf));
+	sgbuf->dev = device;
+	pages = snd_sgbuf_aligned_pages(size);
+	sgbuf->tblsize = sgbuf_align_table(pages);
+	sgbuf->table = kmalloc(sizeof(*sgbuf->table) * sgbuf->tblsize, GFP_KERNEL);
+	if (! sgbuf->table)
+		goto _failed;
+	memset(sgbuf->table, 0, sizeof(*sgbuf->table) * sgbuf->tblsize);
+	sgbuf->page_table = kmalloc(sizeof(*sgbuf->page_table) * sgbuf->tblsize, GFP_KERNEL);
+	if (! sgbuf->page_table)
+		goto _failed;
+	memset(sgbuf->page_table, 0, sizeof(*sgbuf->page_table) * sgbuf->tblsize);
+
+	/* allocate each page */
+	for (i = 0; i < pages; i++) {
+		if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, device, PAGE_SIZE, &tmpb) < 0) {
+			if (res_size == NULL)
+				goto _failed;
+			*res_size = size = sgbuf->pages * PAGE_SIZE;
+			break;
+		}
+		sgbuf->table[i].buf = tmpb.area;
+		sgbuf->table[i].addr = tmpb.addr;
+		sgbuf->page_table[i] = virt_to_page(tmpb.area);
+		sgbuf->pages++;
+	}
+
+	sgbuf->size = size;
+	dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, PAGE_KERNEL);
+	if (! dmab->area)
+		goto _failed;
+	return dmab->area;
+
+ _failed:
+	snd_free_sgbuf_pages(dmab); /* free the table */
+	return NULL;
+}