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authorIngo Molnar <mingo@elte.hu>2009-06-07 12:22:15 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-07 12:22:15 +0200
commit5f4457a4f62cc9d78e04c0eb12ff0540899aad89 (patch)
tree0b973d527ea6b2ae31e08da0746b4965a3c5a6d8 /arch/frv/include/asm/scatterlist.h
parent9b94b3a19b13e094c10f65f24bc358f6ffe4eacd (diff)
parentb87297fb405ef13cac375f202d114323b076a56d (diff)
Merge branch 'linus' into x86/cpu
Diffstat (limited to 'arch/frv/include/asm/scatterlist.h')
-rw-r--r--arch/frv/include/asm/scatterlist.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/arch/frv/include/asm/scatterlist.h b/arch/frv/include/asm/scatterlist.h
new file mode 100644
index 00000000000..4bca8a28546
--- /dev/null
+++ b/arch/frv/include/asm/scatterlist.h
@@ -0,0 +1,46 @@
+#ifndef _ASM_SCATTERLIST_H
+#define _ASM_SCATTERLIST_H
+
+#include <asm/types.h>
+
+/*
+ * Drivers must set either ->address or (preferred) page and ->offset
+ * to indicate where data must be transferred to/from.
+ *
+ * Using page is recommended since it handles highmem data as well as
+ * low mem. ->address is restricted to data which has a virtual mapping, and
+ * it will go away in the future. Updating to page can be automated very
+ * easily -- something like
+ *
+ * sg->address = some_ptr;
+ *
+ * can be rewritten as
+ *
+ * sg_set_buf(sg, some_ptr, length);
+ *
+ * and that's it. There's no excuse for not highmem enabling YOUR driver. /jens
+ */
+struct scatterlist {
+#ifdef CONFIG_DEBUG_SG
+ unsigned long sg_magic;
+#endif
+ unsigned long page_link;
+ unsigned int offset; /* for highmem, page offset */
+
+ dma_addr_t dma_address;
+ unsigned int length;
+};
+
+/*
+ * These macros should be used after a pci_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 pci_map_sg
+ * returns, or alternatively stop on the first sg_dma_len(sg) which
+ * is 0.
+ */
+#define sg_dma_address(sg) ((sg)->dma_address)
+#define sg_dma_len(sg) ((sg)->length)
+
+#define ISA_DMA_THRESHOLD (0xffffffffUL)
+
+#endif /* !_ASM_SCATTERLIST_H */