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Release 4.7 drivers/dma/virt-dma.c

Directory: drivers/dma
/*
 * Virtual DMA channel support for DMAengine
 *
 * Copyright (C) 2012 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/module.h>
#include <linux/spinlock.h>

#include "virt-dma.h"


static struct virt_dma_desc *to_virt_desc(struct dma_async_tx_descriptor *tx) { return container_of(tx, struct virt_dma_desc, tx); }

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dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx) { struct virt_dma_chan *vc = to_virt_chan(tx->chan); struct virt_dma_desc *vd = to_virt_desc(tx); unsigned long flags; dma_cookie_t cookie; spin_lock_irqsave(&vc->lock, flags); cookie = dma_cookie_assign(tx); list_move_tail(&vd->node, &vc->desc_submitted); spin_unlock_irqrestore(&vc->lock, flags); dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: submitted\n", vc, vd, cookie); return cookie; }

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EXPORT_SYMBOL_GPL(vchan_tx_submit); /** * vchan_tx_desc_free - free a reusable descriptor * @tx: the transfer * * This function frees a previously allocated reusable descriptor. The only * other way is to clear the DMA_CTRL_REUSE flag and submit one last time the * transfer. * * Returns 0 upon success */
int vchan_tx_desc_free(struct dma_async_tx_descriptor *tx) { struct virt_dma_chan *vc = to_virt_chan(tx->chan); struct virt_dma_desc *vd = to_virt_desc(tx); unsigned long flags; spin_lock_irqsave(&vc->lock, flags); list_del(&vd->node); spin_unlock_irqrestore(&vc->lock, flags); dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: freeing\n", vc, vd, vd->tx.cookie); vc->desc_free(vd); return 0; }

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EXPORT_SYMBOL_GPL(vchan_tx_desc_free);
struct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *vc, dma_cookie_t cookie) { struct virt_dma_desc *vd; list_for_each_entry(vd, &vc->desc_issued, node) if (vd->tx.cookie == cookie) return vd; return NULL; }

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EXPORT_SYMBOL_GPL(vchan_find_desc); /* * This tasklet handles the completion of a DMA descriptor by * calling its callback and freeing it. */
static void vchan_complete(unsigned long arg) { struct virt_dma_chan *vc = (struct virt_dma_chan *)arg; struct virt_dma_desc *vd; dma_async_tx_callback cb = NULL; void *cb_data = NULL; LIST_HEAD(head); spin_lock_irq(&vc->lock); list_splice_tail_init(&vc->desc_completed, &head); vd = vc->cyclic; if (vd) { vc->cyclic = NULL; cb = vd->tx.callback; cb_data = vd->tx.callback_param; } spin_unlock_irq(&vc->lock); if (cb) cb(cb_data); while (!list_empty(&head)) { vd = list_first_entry(&head, struct virt_dma_desc, node); cb = vd->tx.callback; cb_data = vd->tx.callback_param; list_del(&vd->node); if (dmaengine_desc_test_reuse(&vd->tx)) list_add(&vd->node, &vc->desc_allocated); else vc->desc_free(vd); if (cb) cb(cb_data); } }

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void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head) { while (!list_empty(head)) { struct virt_dma_desc *vd = list_first_entry(head, struct virt_dma_desc, node); if (dmaengine_desc_test_reuse(&vd->tx)) { list_move_tail(&vd->node, &vc->desc_allocated); } else { dev_dbg(vc->chan.device->dev, "txd %p: freeing\n", vd); list_del(&vd->node); vc->desc_free(vd); } } }

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russell kingrussell king6970.41%150.00%
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EXPORT_SYMBOL_GPL(vchan_dma_desc_free_list);
void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev) { dma_cookie_init(&vc->chan); spin_lock_init(&vc->lock); INIT_LIST_HEAD(&vc->desc_allocated); INIT_LIST_HEAD(&vc->desc_submitted); INIT_LIST_HEAD(&vc->desc_issued); INIT_LIST_HEAD(&vc->desc_completed); tasklet_init(&vc->task, vchan_complete, (unsigned long)vc); vc->chan.device = dmadev; list_add_tail(&vc->chan.device_node, &dmadev->channels); }

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EXPORT_SYMBOL_GPL(vchan_init); MODULE_AUTHOR("Russell King"); MODULE_LICENSE("GPL");

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Directory: drivers/dma
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