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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-frv/scatterlist.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-frv/scatterlist.h')
-rw-r--r--include/asm-frv/scatterlist.h32
1 files changed, 32 insertions, 0 deletions
diff --git a/include/asm-frv/scatterlist.h b/include/asm-frv/scatterlist.h
new file mode 100644
index 000000000000..fb38fd329a5f
--- /dev/null
+++ b/include/asm-frv/scatterlist.h
@@ -0,0 +1,32 @@
+#ifndef _ASM_SCATTERLIST_H
+#define _ASM_SCATTERLIST_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->page = virt_to_page(some_ptr);
+ * sg->offset = (unsigned long) some_ptr & ~PAGE_MASK;
+ *
+ * and that's it. There's no excuse for not highmem enabling YOUR driver. /jens
+ */
+struct scatterlist {
+ struct page *page; /* Location for highmem page, if any */
+ unsigned int offset; /* for highmem, page offset */
+
+ dma_addr_t dma_address;
+ unsigned int length;
+};
+
+#define ISA_DMA_THRESHOLD (0xffffffffUL)
+
+#endif /* !_ASM_SCATTERLIST_H */