80 lines
1.8 KiB
C
80 lines
1.8 KiB
C
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// 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-noncoherent.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(struct device *dev, phys_addr_t paddr,
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size_t size, 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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