a08abd8ca8
Prepare the api for the arrival of a new parameter, 'scribble'. This will allow callers to identify scratchpad memory for dma address or page address conversions. As this adds yet another parameter, take this opportunity to convert the common submission parameters (flags, dependency, callback, and callback argument) into an object that is passed by reference. Also, take this opportunity to fix up the kerneldoc and add notes about the relevant ASYNC_TX_* flags for each routine. [ Impact: moves api pass-by-value parameters to a pass-by-reference struct ] Signed-off-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
98 lines
2.6 KiB
C
98 lines
2.6 KiB
C
/*
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* memory fill 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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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/interrupt.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_memset - attempt to fill memory with a dma engine.
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* @dest: destination page
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* @val: fill value
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* @offset: offset in pages to start transaction
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* @len: length in bytes
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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_memset(struct page *dest, int val, unsigned int 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_MEMSET,
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&dest, 1, NULL, 0, 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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if (device) {
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dma_addr_t dma_dest;
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unsigned long dma_prep_flags;
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dma_prep_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0;
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dma_dest = dma_map_page(device->dev, dest, offset, len,
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DMA_FROM_DEVICE);
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tx = device->device_prep_dma_memset(chan, dma_dest, val, 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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async_tx_submit(chan, tx, submit);
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} else { /* run the memset synchronously */
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void *dest_buf;
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pr_debug("%s: (sync) len: %zu\n", __func__, len);
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dest_buf = page_address(dest) + offset;
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/* wait for any prerequisite operations */
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async_tx_quiesce(&submit->depend_tx);
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memset(dest_buf, val, len);
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async_tx_sync_epilog(submit);
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}
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return tx;
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}
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EXPORT_SYMBOL_GPL(async_memset);
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static int __init async_memset_init(void)
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{
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return 0;
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}
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static void __exit async_memset_exit(void)
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{
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do { } while (0);
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}
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module_init(async_memset_init);
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module_exit(async_memset_exit);
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MODULE_AUTHOR("Intel Corporation");
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MODULE_DESCRIPTION("asynchronous memset api");
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MODULE_LICENSE("GPL");
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