2 * Port on Texas Instruments TMS320C6x architecture
4 * Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
5 * Author: Aurelien Jacquiot <aurelien.jacquiot@ti.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * DMA uncached mapping support.
13 * Using code pulled from ARM
14 * Copyright (C) 2000-2004 Russell King
17 #include <linux/slab.h>
18 #include <linux/bitmap.h>
19 #include <linux/bitops.h>
20 #include <linux/module.h>
21 #include <linux/interrupt.h>
22 #include <linux/dma-noncoherent.h>
23 #include <linux/memblock.h>
25 #include <asm/cacheflush.h>
27 #include <asm/setup.h>
30 * DMA coherent memory management, can be redefined using the memdma=
35 static phys_addr_t dma_base;
39 static unsigned long *dma_bitmap;
42 static DEFINE_SPINLOCK(dma_lock);
45 * Return a DMA coherent and contiguous memory chunk from the DMA memory
47 static inline u32 __alloc_dma_pages(int order)
52 spin_lock_irqsave(&dma_lock, flags);
53 pos = bitmap_find_free_region(dma_bitmap, dma_pages, order);
54 spin_unlock_irqrestore(&dma_lock, flags);
56 return dma_base + (pos << PAGE_SHIFT);
59 static void __free_dma_pages(u32 addr, int order)
62 u32 pos = (addr - dma_base) >> PAGE_SHIFT;
64 if (addr < dma_base || (pos + (1 << order)) >= dma_pages) {
65 printk(KERN_ERR "%s: freeing outside range.\n", __func__);
69 spin_lock_irqsave(&dma_lock, flags);
70 bitmap_release_region(dma_bitmap, pos, order);
71 spin_unlock_irqrestore(&dma_lock, flags);
75 * Allocate DMA coherent memory space and return both the kernel
76 * virtual and DMA address for that space.
78 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
79 gfp_t gfp, unsigned long attrs)
85 if (!dma_size || !size)
88 order = get_count_order(((size - 1) >> PAGE_SHIFT) + 1);
90 paddr = __alloc_dma_pages(order);
98 ret = phys_to_virt(paddr);
99 memset(ret, 0, 1 << order);
104 * Free DMA coherent memory as defined by the above mapping.
106 void arch_dma_free(struct device *dev, size_t size, void *vaddr,
107 dma_addr_t dma_handle, unsigned long attrs)
111 if (!dma_size || !size)
114 order = get_count_order(((size - 1) >> PAGE_SHIFT) + 1);
116 __free_dma_pages(virt_to_phys(vaddr), order);
120 * Initialise the coherent DMA memory allocator using the given uncached region.
122 void __init coherent_mem_init(phys_addr_t start, u32 size)
128 "Coherent memory (DMA) region start=0x%x size=0x%x\n",
134 /* allocate bitmap */
135 dma_pages = dma_size >> PAGE_SHIFT;
136 if (dma_size & (PAGE_SIZE - 1))
139 dma_bitmap = memblock_alloc(BITS_TO_LONGS(dma_pages) * sizeof(long),
142 panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
143 __func__, BITS_TO_LONGS(dma_pages) * sizeof(long),
147 static void c6x_dma_sync(struct device *dev, phys_addr_t paddr, size_t size,
148 enum dma_data_direction dir)
150 BUG_ON(!valid_dma_direction(dir));
153 case DMA_FROM_DEVICE:
154 L2_cache_block_invalidate(paddr, paddr + size);
157 L2_cache_block_writeback(paddr, paddr + size);
159 case DMA_BIDIRECTIONAL:
160 L2_cache_block_writeback_invalidate(paddr, paddr + size);
167 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
168 size_t size, enum dma_data_direction dir)
170 return c6x_dma_sync(dev, paddr, size, dir);
173 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
174 size_t size, enum dma_data_direction dir)
176 return c6x_dma_sync(dev, paddr, size, dir);