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79 lines
1.8 KiB
79 lines
1.8 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* DMA implementation for Hexagon |
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* |
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* Copyright (c) 2010-2012, The Linux Foundation. All rights reserved. |
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*/ |
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#include <linux/dma-map-ops.h> |
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#include <linux/memblock.h> |
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#include <linux/genalloc.h> |
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#include <linux/module.h> |
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#include <asm/page.h> |
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static struct gen_pool *coherent_pool; |
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/* Allocates from a pool of uncached memory that was reserved at boot time */ |
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void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_addr, |
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gfp_t flag, unsigned long attrs) |
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{ |
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void *ret; |
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/* |
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* Our max_low_pfn should have been backed off by 16MB in |
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* mm/init.c to create DMA coherent space. Use that as the VA |
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* for the pool. |
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*/ |
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if (coherent_pool == NULL) { |
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coherent_pool = gen_pool_create(PAGE_SHIFT, -1); |
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if (coherent_pool == NULL) |
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panic("Can't create %s() memory pool!", __func__); |
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else |
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gen_pool_add(coherent_pool, |
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(unsigned long)pfn_to_virt(max_low_pfn), |
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hexagon_coherent_pool_size, -1); |
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} |
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ret = (void *) gen_pool_alloc(coherent_pool, size); |
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if (ret) { |
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memset(ret, 0, size); |
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*dma_addr = (dma_addr_t) virt_to_phys(ret); |
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} else |
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*dma_addr = ~0; |
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return ret; |
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} |
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void arch_dma_free(struct device *dev, size_t size, void *vaddr, |
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dma_addr_t dma_addr, unsigned long attrs) |
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{ |
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gen_pool_free(coherent_pool, (unsigned long) vaddr, size); |
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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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void *addr = phys_to_virt(paddr); |
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switch (dir) { |
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case DMA_TO_DEVICE: |
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hexagon_clean_dcache_range((unsigned long) addr, |
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(unsigned long) addr + size); |
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break; |
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case DMA_FROM_DEVICE: |
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hexagon_inv_dcache_range((unsigned long) addr, |
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(unsigned long) addr + size); |
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break; |
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case DMA_BIDIRECTIONAL: |
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flush_dcache_range((unsigned long) addr, |
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(unsigned long) addr + size); |
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break; |
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default: |
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BUG(); |
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} |
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}
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