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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2006-09-25 23:32:13 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 08:48:54 -0700
commit5f97f7f9400de47ae837170bb274e90ad3934386 (patch)
tree514451e6dc6b46253293a00035d375e77b1c65ed /arch/avr32/mm/dma-coherent.c
parent53e62d3aaa60590d4a69b4e07c29f448b5151047 (diff)
downloadlinux-5f97f7f9400de47ae837170bb274e90ad3934386.tar.gz
[PATCH] avr32 architecture
This adds support for the Atmel AVR32 architecture as well as the AT32AP7000 CPU and the AT32STK1000 development board. AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for cost-sensitive embedded applications, with particular emphasis on low power consumption and high code density. The AVR32 architecture is not binary compatible with earlier 8-bit AVR architectures. The AVR32 architecture, including the instruction set, is described by the AVR32 Architecture Manual, available from http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture. It features a 7-stage pipeline, 16KB instruction and data caches and a full Memory Management Unit. It also comes with a large set of integrated peripherals, many of which are shared with the AT91 ARM-based controllers from Atmel. Full data sheet is available from http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf while the CPU core implementation including caches and MMU is documented by the AVR32 AP Technical Reference, available from http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf Information about the AT32STK1000 development board can be found at http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918 including a BSP CD image with an earlier version of this patch, development tools (binaries and source/patches) and a root filesystem image suitable for booting from SD card. Alternatively, there's a preliminary "getting started" guide available at http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links to the sources and patches you will need in order to set up a cross-compiling environment for avr32-linux. This patch, as well as the other patches included with the BSP and the toolchain patches, is actively supported by Atmel Corporation. [dmccr@us.ibm.com: Fix more pxx_page macro locations] [bunk@stusta.de: fix `make defconfig'] Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Dave McCracken <dmccr@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/avr32/mm/dma-coherent.c')
-rw-r--r--arch/avr32/mm/dma-coherent.c139
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/avr32/mm/dma-coherent.c b/arch/avr32/mm/dma-coherent.c
new file mode 100644
index 0000000..44ab8a7
--- /dev/null
+++ b/arch/avr32/mm/dma-coherent.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/dma-mapping.h>
+
+#include <asm/addrspace.h>
+#include <asm/cacheflush.h>
+
+void dma_cache_sync(void *vaddr, size_t size, int direction)
+{
+ /*
+ * No need to sync an uncached area
+ */
+ if (PXSEG(vaddr) == P2SEG)
+ return;
+
+ switch (direction) {
+ case DMA_FROM_DEVICE: /* invalidate only */
+ dma_cache_inv(vaddr, size);
+ break;
+ case DMA_TO_DEVICE: /* writeback only */
+ dma_cache_wback(vaddr, size);
+ break;
+ case DMA_BIDIRECTIONAL: /* writeback and invalidate */
+ dma_cache_wback_inv(vaddr, size);
+ break;
+ default:
+ BUG();
+ }
+}
+EXPORT_SYMBOL(dma_cache_sync);
+
+static struct page *__dma_alloc(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp)
+{
+ struct page *page, *free, *end;
+ int order;
+
+ size = PAGE_ALIGN(size);
+ order = get_order(size);
+
+ page = alloc_pages(gfp, order);
+ if (!page)
+ return NULL;
+ split_page(page, order);
+
+ /*
+ * When accessing physical memory with valid cache data, we
+ * get a cache hit even if the virtual memory region is marked
+ * as uncached.
+ *
+ * Since the memory is newly allocated, there is no point in
+ * doing a writeback. If the previous owner cares, he should
+ * have flushed the cache before releasing the memory.
+ */
+ invalidate_dcache_region(phys_to_virt(page_to_phys(page)), size);
+
+ *handle = page_to_bus(page);
+ free = page + (size >> PAGE_SHIFT);
+ end = page + (1 << order);
+
+ /*
+ * Free any unused pages
+ */
+ while (free < end) {
+ __free_page(free);
+ free++;
+ }
+
+ return page;
+}
+
+static void __dma_free(struct device *dev, size_t size,
+ struct page *page, dma_addr_t handle)
+{
+ struct page *end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
+
+ while (page < end)
+ __free_page(page++);
+}
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp)
+{
+ struct page *page;
+ void *ret = NULL;
+
+ page = __dma_alloc(dev, size, handle, gfp);
+ if (page)
+ ret = phys_to_uncached(page_to_phys(page));
+
+ return ret;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+void dma_free_coherent(struct device *dev, size_t size,
+ void *cpu_addr, dma_addr_t handle)
+{
+ void *addr = phys_to_cached(uncached_to_phys(cpu_addr));
+ struct page *page;
+
+ pr_debug("dma_free_coherent addr %p (phys %08lx) size %u\n",
+ cpu_addr, (unsigned long)handle, (unsigned)size);
+ BUG_ON(!virt_addr_valid(addr));
+ page = virt_to_page(addr);
+ __dma_free(dev, size, page, handle);
+}
+EXPORT_SYMBOL(dma_free_coherent);
+
+#if 0
+void *dma_alloc_writecombine(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp)
+{
+ struct page *page;
+
+ page = __dma_alloc(dev, size, handle, gfp);
+
+ /* Now, map the page into P3 with write-combining turned on */
+ return __ioremap(page_to_phys(page), size, _PAGE_BUFFER);
+}
+EXPORT_SYMBOL(dma_alloc_writecombine);
+
+void dma_free_writecombine(struct device *dev, size_t size,
+ void *cpu_addr, dma_addr_t handle)
+{
+ struct page *page;
+
+ iounmap(cpu_addr);
+
+ page = bus_to_page(handle);
+ __dma_free(dev, size, page, handle);
+}
+EXPORT_SYMBOL(dma_free_writecombine);
+#endif