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124 lines
3.2 KiB
124 lines
3.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* PowerPC version derived from arch/arm/mm/consistent.c |
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* Copyright (C) 2001 Dan Malek ([email protected]) |
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* |
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* Copyright (C) 2000 Russell King |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/errno.h> |
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#include <linux/types.h> |
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#include <linux/highmem.h> |
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#include <linux/dma-direct.h> |
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#include <linux/dma-map-ops.h> |
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#include <asm/tlbflush.h> |
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#include <asm/dma.h> |
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/* |
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* make an area consistent. |
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*/ |
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static void __dma_sync(void *vaddr, size_t size, int direction) |
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{ |
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unsigned long start = (unsigned long)vaddr; |
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unsigned long end = start + size; |
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switch (direction) { |
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case DMA_NONE: |
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BUG(); |
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case DMA_FROM_DEVICE: |
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/* |
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* invalidate only when cache-line aligned otherwise there is |
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* the potential for discarding uncommitted data from the cache |
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*/ |
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if ((start | end) & (L1_CACHE_BYTES - 1)) |
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flush_dcache_range(start, end); |
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else |
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invalidate_dcache_range(start, end); |
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break; |
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case DMA_TO_DEVICE: /* writeback only */ |
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clean_dcache_range(start, end); |
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break; |
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case DMA_BIDIRECTIONAL: /* writeback and invalidate */ |
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flush_dcache_range(start, end); |
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break; |
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} |
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} |
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#ifdef CONFIG_HIGHMEM |
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/* |
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* __dma_sync_page() implementation for systems using highmem. |
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* In this case, each page of a buffer must be kmapped/kunmapped |
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* in order to have a virtual address for __dma_sync(). This must |
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* not sleep so kmap_atomic()/kunmap_atomic() are used. |
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* |
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* Note: yes, it is possible and correct to have a buffer extend |
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* beyond the first page. |
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*/ |
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static inline void __dma_sync_page_highmem(struct page *page, |
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unsigned long offset, size_t size, int direction) |
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{ |
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size_t seg_size = min((size_t)(PAGE_SIZE - offset), size); |
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size_t cur_size = seg_size; |
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unsigned long flags, start, seg_offset = offset; |
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int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE; |
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int seg_nr = 0; |
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local_irq_save(flags); |
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do { |
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start = (unsigned long)kmap_atomic(page + seg_nr) + seg_offset; |
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/* Sync this buffer segment */ |
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__dma_sync((void *)start, seg_size, direction); |
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kunmap_atomic((void *)start); |
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seg_nr++; |
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/* Calculate next buffer segment size */ |
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seg_size = min((size_t)PAGE_SIZE, size - cur_size); |
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/* Add the segment size to our running total */ |
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cur_size += seg_size; |
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seg_offset = 0; |
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} while (seg_nr < nr_segs); |
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local_irq_restore(flags); |
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} |
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#endif /* CONFIG_HIGHMEM */ |
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/* |
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* __dma_sync_page makes memory consistent. identical to __dma_sync, but |
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* takes a struct page instead of a virtual address |
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*/ |
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static void __dma_sync_page(phys_addr_t paddr, size_t size, int dir) |
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{ |
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struct page *page = pfn_to_page(paddr >> PAGE_SHIFT); |
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unsigned offset = paddr & ~PAGE_MASK; |
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#ifdef CONFIG_HIGHMEM |
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__dma_sync_page_highmem(page, offset, size, dir); |
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#else |
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unsigned long start = (unsigned long)page_address(page) + offset; |
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__dma_sync((void *)start, size, dir); |
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#endif |
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} |
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void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, |
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enum dma_data_direction dir) |
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{ |
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__dma_sync_page(paddr, size, dir); |
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} |
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void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, |
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enum dma_data_direction dir) |
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{ |
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__dma_sync_page(paddr, size, dir); |
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} |
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void arch_dma_prep_coherent(struct page *page, size_t size) |
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{ |
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unsigned long kaddr = (unsigned long)page_address(page); |
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flush_dcache_range(kaddr, kaddr + size); |
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}
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