forked from Minki/linux
09d5b702b0
This allows each virtual channel to store information about each transfer that completed, i.e. which transfer succeeded (or which failed) and if there was any residue data on each (completed) transfer. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Vinod Koul <vkoul@kernel.org>
151 lines
3.7 KiB
C
151 lines
3.7 KiB
C
/*
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* Virtual DMA channel support for DMAengine
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*
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* Copyright (C) 2012 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/device.h>
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#include <linux/dmaengine.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include "virt-dma.h"
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static struct virt_dma_desc *to_virt_desc(struct dma_async_tx_descriptor *tx)
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{
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return container_of(tx, struct virt_dma_desc, tx);
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}
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dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx)
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{
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struct virt_dma_chan *vc = to_virt_chan(tx->chan);
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struct virt_dma_desc *vd = to_virt_desc(tx);
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unsigned long flags;
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dma_cookie_t cookie;
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spin_lock_irqsave(&vc->lock, flags);
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cookie = dma_cookie_assign(tx);
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list_move_tail(&vd->node, &vc->desc_submitted);
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spin_unlock_irqrestore(&vc->lock, flags);
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dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: submitted\n",
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vc, vd, cookie);
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return cookie;
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}
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EXPORT_SYMBOL_GPL(vchan_tx_submit);
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/**
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* vchan_tx_desc_free - free a reusable descriptor
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* @tx: the transfer
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*
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* This function frees a previously allocated reusable descriptor. The only
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* other way is to clear the DMA_CTRL_REUSE flag and submit one last time the
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* transfer.
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*
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* Returns 0 upon success
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*/
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int vchan_tx_desc_free(struct dma_async_tx_descriptor *tx)
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{
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struct virt_dma_chan *vc = to_virt_chan(tx->chan);
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struct virt_dma_desc *vd = to_virt_desc(tx);
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unsigned long flags;
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spin_lock_irqsave(&vc->lock, flags);
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list_del(&vd->node);
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spin_unlock_irqrestore(&vc->lock, flags);
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dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: freeing\n",
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vc, vd, vd->tx.cookie);
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vc->desc_free(vd);
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return 0;
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}
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EXPORT_SYMBOL_GPL(vchan_tx_desc_free);
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struct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *vc,
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dma_cookie_t cookie)
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{
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struct virt_dma_desc *vd;
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list_for_each_entry(vd, &vc->desc_issued, node)
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if (vd->tx.cookie == cookie)
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return vd;
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return NULL;
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}
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EXPORT_SYMBOL_GPL(vchan_find_desc);
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/*
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* This tasklet handles the completion of a DMA descriptor by
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* calling its callback and freeing it.
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*/
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static void vchan_complete(unsigned long arg)
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{
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struct virt_dma_chan *vc = (struct virt_dma_chan *)arg;
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struct virt_dma_desc *vd, *_vd;
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struct dmaengine_desc_callback cb;
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LIST_HEAD(head);
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spin_lock_irq(&vc->lock);
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list_splice_tail_init(&vc->desc_completed, &head);
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vd = vc->cyclic;
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if (vd) {
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vc->cyclic = NULL;
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dmaengine_desc_get_callback(&vd->tx, &cb);
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} else {
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memset(&cb, 0, sizeof(cb));
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}
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spin_unlock_irq(&vc->lock);
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dmaengine_desc_callback_invoke(&cb, &vd->tx_result);
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list_for_each_entry_safe(vd, _vd, &head, node) {
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dmaengine_desc_get_callback(&vd->tx, &cb);
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list_del(&vd->node);
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vchan_vdesc_fini(vd);
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dmaengine_desc_callback_invoke(&cb, &vd->tx_result);
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}
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}
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void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head)
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{
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struct virt_dma_desc *vd, *_vd;
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list_for_each_entry_safe(vd, _vd, head, node) {
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if (dmaengine_desc_test_reuse(&vd->tx)) {
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list_move_tail(&vd->node, &vc->desc_allocated);
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} else {
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dev_dbg(vc->chan.device->dev, "txd %p: freeing\n", vd);
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list_del(&vd->node);
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vc->desc_free(vd);
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}
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}
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}
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EXPORT_SYMBOL_GPL(vchan_dma_desc_free_list);
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void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev)
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{
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dma_cookie_init(&vc->chan);
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spin_lock_init(&vc->lock);
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INIT_LIST_HEAD(&vc->desc_allocated);
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INIT_LIST_HEAD(&vc->desc_submitted);
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INIT_LIST_HEAD(&vc->desc_issued);
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INIT_LIST_HEAD(&vc->desc_completed);
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tasklet_init(&vc->task, vchan_complete, (unsigned long)vc);
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vc->chan.device = dmadev;
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list_add_tail(&vc->chan.device_node, &dmadev->channels);
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}
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EXPORT_SYMBOL_GPL(vchan_init);
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MODULE_AUTHOR("Russell King");
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MODULE_LICENSE("GPL");
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