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97 lines
2.6 KiB
97 lines
2.6 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* copy offload engine support |
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* |
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* Copyright © 2006, Intel Corporation. |
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* |
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* Dan Williams <[email protected]> |
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* |
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* with architecture considerations by: |
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* Neil Brown <[email protected]> |
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* Jeff Garzik <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/highmem.h> |
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#include <linux/module.h> |
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#include <linux/mm.h> |
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#include <linux/dma-mapping.h> |
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#include <linux/async_tx.h> |
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/** |
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* async_memcpy - attempt to copy memory with a dma engine. |
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* @dest: destination page |
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* @src: src page |
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* @dest_offset: offset into 'dest' to start transaction |
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* @src_offset: offset into 'src' to start transaction |
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* @len: length in bytes |
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* @submit: submission / completion modifiers |
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* |
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* honored flags: ASYNC_TX_ACK |
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*/ |
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struct dma_async_tx_descriptor * |
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async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset, |
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unsigned int src_offset, size_t len, |
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struct async_submit_ctl *submit) |
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{ |
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struct dma_chan *chan = async_tx_find_channel(submit, DMA_MEMCPY, |
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&dest, 1, &src, 1, len); |
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struct dma_device *device = chan ? chan->device : NULL; |
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struct dma_async_tx_descriptor *tx = NULL; |
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struct dmaengine_unmap_data *unmap = NULL; |
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if (device) |
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unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT); |
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if (unmap && is_dma_copy_aligned(device, src_offset, dest_offset, len)) { |
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unsigned long dma_prep_flags = 0; |
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if (submit->cb_fn) |
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dma_prep_flags |= DMA_PREP_INTERRUPT; |
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if (submit->flags & ASYNC_TX_FENCE) |
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dma_prep_flags |= DMA_PREP_FENCE; |
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unmap->to_cnt = 1; |
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unmap->addr[0] = dma_map_page(device->dev, src, src_offset, len, |
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DMA_TO_DEVICE); |
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unmap->from_cnt = 1; |
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unmap->addr[1] = dma_map_page(device->dev, dest, dest_offset, len, |
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DMA_FROM_DEVICE); |
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unmap->len = len; |
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tx = device->device_prep_dma_memcpy(chan, unmap->addr[1], |
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unmap->addr[0], len, |
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dma_prep_flags); |
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} |
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if (tx) { |
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pr_debug("%s: (async) len: %zu\n", __func__, len); |
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dma_set_unmap(tx, unmap); |
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async_tx_submit(chan, tx, submit); |
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} else { |
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void *dest_buf, *src_buf; |
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pr_debug("%s: (sync) len: %zu\n", __func__, len); |
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/* wait for any prerequisite operations */ |
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async_tx_quiesce(&submit->depend_tx); |
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dest_buf = kmap_atomic(dest) + dest_offset; |
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src_buf = kmap_atomic(src) + src_offset; |
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memcpy(dest_buf, src_buf, len); |
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kunmap_atomic(src_buf); |
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kunmap_atomic(dest_buf); |
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async_tx_sync_epilog(submit); |
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} |
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dmaengine_unmap_put(unmap); |
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return tx; |
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} |
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EXPORT_SYMBOL_GPL(async_memcpy); |
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MODULE_AUTHOR("Intel Corporation"); |
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MODULE_DESCRIPTION("asynchronous memcpy api"); |
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MODULE_LICENSE("GPL");
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