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author | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2006-09-25 23:32:13 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 08:48:54 -0700 |
commit | 5f97f7f9400de47ae837170bb274e90ad3934386 (patch) | |
tree | 514451e6dc6b46253293a00035d375e77b1c65ed /arch/avr32/mm/dma-coherent.c | |
parent | 53e62d3aaa60590d4a69b4e07c29f448b5151047 (diff) | |
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[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.c | 139 |
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 |