Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block

[karo-tx-linux.git] / include / linux / scatterlist.h

diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index a0edb992c9c31a76bf314eb6f443c24c230083ce..50a8486c524bb29491bd4540afa4781596abdfdd 100644 (file)
--- 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.