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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 111 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
98 lines
2.6 KiB
C
98 lines
2.6 KiB
C
// 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 <dan.j.williams@intel.com>
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*
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* with architecture considerations by:
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* Neil Brown <neilb@suse.de>
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* Jeff Garzik <jeff@garzik.org>
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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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