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-rw-r--r--include/linux/scatterlist.h39
1 files changed, 32 insertions, 7 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index ed8f9e7..eca1ec9 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -2,13 +2,39 @@
#define _LINUX_SCATTERLIST_H
#include <linux/string.h>
+#include <linux/types.h>
#include <linux/bug.h>
#include <linux/mm.h>
-
-#include <asm/types.h>
-#include <asm/scatterlist.h>
#include <asm/io.h>
+struct scatterlist {
+#ifdef CONFIG_DEBUG_SG
+ unsigned long sg_magic;
+#endif
+ unsigned long page_link;
+ unsigned int offset;
+ unsigned int length;
+ dma_addr_t dma_address;
+#ifdef CONFIG_NEED_SG_DMA_LENGTH
+ unsigned int dma_length;
+#endif
+};
+
+/*
+ * These macros should be used after a dma_map_sg call has been done
+ * to get bus addresses of each of the SG entries and their lengths.
+ * You should only work with the number of sg entries dma_map_sg
+ * returns, or alternatively stop on the first sg_dma_len(sg) which
+ * is 0.
+ */
+#define sg_dma_address(sg) ((sg)->dma_address)
+
+#ifdef CONFIG_NEED_SG_DMA_LENGTH
+#define sg_dma_len(sg) ((sg)->dma_length)
+#else
+#define sg_dma_len(sg) ((sg)->length)
+#endif
+
struct sg_table {
struct scatterlist *sgl; /* the list */
unsigned int nents; /* number of mapped entries */
@@ -18,10 +44,9 @@ struct sg_table {
/*
* Notes on SG table design.
*
- * Architectures must provide an unsigned long page_link field in the
- * scatterlist struct. We use that to place the page pointer AND encode
- * information about the sg table as well. The two lower bits are reserved
- * for this information.
+ * We use the unsigned long page_link field in the scatterlist struct to place
+ * the page pointer AND encode information about the sg table as well. The two
+ * lower bits are reserved for this information.
*
* If bit 0 is set, then the page_link contains a pointer to the next sg
* table list. Otherwise the next entry is at sg + 1.
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