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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 | // SPDX-License-Identifier: GPL-2.0-only /* * Port on Texas Instruments TMS320C6x architecture * * Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated * Author: Aurelien Jacquiot <aurelien.jacquiot@ti.com> * * DMA uncached mapping support. * * Using code pulled from ARM * Copyright (C) 2000-2004 Russell King */ #include <linux/slab.h> #include <linux/bitmap.h> #include <linux/bitops.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/dma-noncoherent.h> #include <linux/memblock.h> #include <asm/cacheflush.h> #include <asm/page.h> #include <asm/setup.h> /* * DMA coherent memory management, can be redefined using the memdma= * kernel command line */ /* none by default */ static phys_addr_t dma_base; static u32 dma_size; static u32 dma_pages; static unsigned long *dma_bitmap; /* bitmap lock */ static DEFINE_SPINLOCK(dma_lock); /* * Return a DMA coherent and contiguous memory chunk from the DMA memory */ static inline u32 __alloc_dma_pages(int order) { unsigned long flags; u32 pos; spin_lock_irqsave(&dma_lock, flags); pos = bitmap_find_free_region(dma_bitmap, dma_pages, order); spin_unlock_irqrestore(&dma_lock, flags); return dma_base + (pos << PAGE_SHIFT); } static void __free_dma_pages(u32 addr, int order) { unsigned long flags; u32 pos = (addr - dma_base) >> PAGE_SHIFT; if (addr < dma_base || (pos + (1 << order)) >= dma_pages) { printk(KERN_ERR "%s: freeing outside range.\n", __func__); BUG(); } spin_lock_irqsave(&dma_lock, flags); bitmap_release_region(dma_bitmap, pos, order); spin_unlock_irqrestore(&dma_lock, flags); } /* * Allocate DMA coherent memory space and return both the kernel * virtual and DMA address for that space. */ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, unsigned long attrs) { void *ret; u32 paddr; int order; if (!dma_size || !size) return NULL; order = get_count_order(((size - 1) >> PAGE_SHIFT) + 1); paddr = __alloc_dma_pages(order); if (handle) *handle = paddr; if (!paddr) return NULL; ret = phys_to_virt(paddr); memset(ret, 0, 1 << order); return ret; } /* * Free DMA coherent memory as defined by the above mapping. */ void arch_dma_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, unsigned long attrs) { int order; if (!dma_size || !size) return; order = get_count_order(((size - 1) >> PAGE_SHIFT) + 1); __free_dma_pages(virt_to_phys(vaddr), order); } /* * Initialise the coherent DMA memory allocator using the given uncached region. */ void __init coherent_mem_init(phys_addr_t start, u32 size) { if (!size) return; printk(KERN_INFO "Coherent memory (DMA) region start=0x%x size=0x%x\n", start, size); dma_base = start; dma_size = size; /* allocate bitmap */ dma_pages = dma_size >> PAGE_SHIFT; if (dma_size & (PAGE_SIZE - 1)) ++dma_pages; dma_bitmap = memblock_alloc(BITS_TO_LONGS(dma_pages) * sizeof(long), sizeof(long)); if (!dma_bitmap) panic("%s: Failed to allocate %zu bytes align=0x%zx\n", __func__, BITS_TO_LONGS(dma_pages) * sizeof(long), sizeof(long)); } static void c6x_dma_sync(phys_addr_t paddr, size_t size, enum dma_data_direction dir) { BUG_ON(!valid_dma_direction(dir)); switch (dir) { case DMA_FROM_DEVICE: L2_cache_block_invalidate(paddr, paddr + size); break; case DMA_TO_DEVICE: L2_cache_block_writeback(paddr, paddr + size); break; case DMA_BIDIRECTIONAL: L2_cache_block_writeback_invalidate(paddr, paddr + size); break; default: break; } } void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, enum dma_data_direction dir) { return c6x_dma_sync(paddr, size, dir); } void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, enum dma_data_direction dir) { return c6x_dma_sync(paddr, size, dir); } |