[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6

The attached patches provides part 6 of an architecture implementation for the
Tensilica Xtensa CPU series.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 61 insertions, 0 deletions

diff --git a/include/asm-xtensa/dma.h b/include/asm-xtensa/dma.h
new file mode 100644
index 000000000000..1c22b0234586
--- /dev/null
+++ b/include/asm-xtensa/dma.h
@@ -0,0 +1,61 @@
+/*
+ * include/asm-xtensa/dma.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2003 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_DMA_H
+#define _XTENSA_DMA_H
+
+#include <linux/config.h>
+#include <asm/io.h>             /* need byte IO */
+#include <xtensa/config/core.h>
+
+/*
+ * This is only to be defined if we have PC-like DMA.
+ * By default this is not true on an Xtensa processor,
+ * however on boards with a PCI bus, such functionality
+ * might be emulated externally.
+ *
+ * NOTE:  there still exists driver code that assumes
+ * this is defined, eg. drivers/sound/soundcard.c (as of 2.4).
+ */
+#define MAX_DMA_CHANNELS        8
+
+/*
+ * The maximum virtual address to which DMA transfers
+ * can be performed on this platform.
+ *
+ * NOTE: This is board (platform) specific, not processor-specific!
+ *
+ * NOTE: This assumes DMA transfers can only be performed on
+ *      the section of physical memory contiguously mapped in virtual
+ *      space for the kernel.  For the Xtensa architecture, this
+ *      means the maximum possible size of this DMA area is
+ *      the size of the statically mapped kernel segment
+ *      (XCHAL_KSEG_{CACHED,BYPASS}_SIZE), ie. 128 MB.
+ *
+ * NOTE: When the entire KSEG area is DMA capable, we substract
+ *      one from the max address so that the virt_to_phys() macro
+ *      works correctly on the address (otherwise the address
+ *      enters another area, and virt_to_phys() may not return
+ *      the value desired).
+ */
+#define MAX_DMA_ADDRESS         (PAGE_OFFSET + XCHAL_KSEG_CACHED_SIZE - 1)
+
+/* Reserve and release a DMA channel */
+extern int request_dma(unsigned int dmanr, const char * device_id);
+extern void free_dma(unsigned int dmanr);
+
+#ifdef CONFIG_PCI
+extern int isa_dma_bridge_buggy;
+#else
+#define isa_dma_bridge_buggy    (0)
+#endif
+
+
+#endif