162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-only 262306a36Sopenharmony_ci/* 362306a36Sopenharmony_ci * Virtual DMA channel support for DMAengine 462306a36Sopenharmony_ci * 562306a36Sopenharmony_ci * Copyright (C) 2012 Russell King 662306a36Sopenharmony_ci */ 762306a36Sopenharmony_ci#include <linux/device.h> 862306a36Sopenharmony_ci#include <linux/dmaengine.h> 962306a36Sopenharmony_ci#include <linux/module.h> 1062306a36Sopenharmony_ci#include <linux/spinlock.h> 1162306a36Sopenharmony_ci 1262306a36Sopenharmony_ci#include "virt-dma.h" 1362306a36Sopenharmony_ci 1462306a36Sopenharmony_cistatic struct virt_dma_desc *to_virt_desc(struct dma_async_tx_descriptor *tx) 1562306a36Sopenharmony_ci{ 1662306a36Sopenharmony_ci return container_of(tx, struct virt_dma_desc, tx); 1762306a36Sopenharmony_ci} 1862306a36Sopenharmony_ci 1962306a36Sopenharmony_cidma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx) 2062306a36Sopenharmony_ci{ 2162306a36Sopenharmony_ci struct virt_dma_chan *vc = to_virt_chan(tx->chan); 2262306a36Sopenharmony_ci struct virt_dma_desc *vd = to_virt_desc(tx); 2362306a36Sopenharmony_ci unsigned long flags; 2462306a36Sopenharmony_ci dma_cookie_t cookie; 2562306a36Sopenharmony_ci 2662306a36Sopenharmony_ci spin_lock_irqsave(&vc->lock, flags); 2762306a36Sopenharmony_ci cookie = dma_cookie_assign(tx); 2862306a36Sopenharmony_ci 2962306a36Sopenharmony_ci list_move_tail(&vd->node, &vc->desc_submitted); 3062306a36Sopenharmony_ci spin_unlock_irqrestore(&vc->lock, flags); 3162306a36Sopenharmony_ci 3262306a36Sopenharmony_ci dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: submitted\n", 3362306a36Sopenharmony_ci vc, vd, cookie); 3462306a36Sopenharmony_ci 3562306a36Sopenharmony_ci return cookie; 3662306a36Sopenharmony_ci} 3762306a36Sopenharmony_ciEXPORT_SYMBOL_GPL(vchan_tx_submit); 3862306a36Sopenharmony_ci 3962306a36Sopenharmony_ci/** 4062306a36Sopenharmony_ci * vchan_tx_desc_free - free a reusable descriptor 4162306a36Sopenharmony_ci * @tx: the transfer 4262306a36Sopenharmony_ci * 4362306a36Sopenharmony_ci * This function frees a previously allocated reusable descriptor. The only 4462306a36Sopenharmony_ci * other way is to clear the DMA_CTRL_REUSE flag and submit one last time the 4562306a36Sopenharmony_ci * transfer. 4662306a36Sopenharmony_ci * 4762306a36Sopenharmony_ci * Returns 0 upon success 4862306a36Sopenharmony_ci */ 4962306a36Sopenharmony_ciint vchan_tx_desc_free(struct dma_async_tx_descriptor *tx) 5062306a36Sopenharmony_ci{ 5162306a36Sopenharmony_ci struct virt_dma_chan *vc = to_virt_chan(tx->chan); 5262306a36Sopenharmony_ci struct virt_dma_desc *vd = to_virt_desc(tx); 5362306a36Sopenharmony_ci unsigned long flags; 5462306a36Sopenharmony_ci 5562306a36Sopenharmony_ci spin_lock_irqsave(&vc->lock, flags); 5662306a36Sopenharmony_ci list_del(&vd->node); 5762306a36Sopenharmony_ci spin_unlock_irqrestore(&vc->lock, flags); 5862306a36Sopenharmony_ci 5962306a36Sopenharmony_ci dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: freeing\n", 6062306a36Sopenharmony_ci vc, vd, vd->tx.cookie); 6162306a36Sopenharmony_ci vc->desc_free(vd); 6262306a36Sopenharmony_ci return 0; 6362306a36Sopenharmony_ci} 6462306a36Sopenharmony_ciEXPORT_SYMBOL_GPL(vchan_tx_desc_free); 6562306a36Sopenharmony_ci 6662306a36Sopenharmony_cistruct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *vc, 6762306a36Sopenharmony_ci dma_cookie_t cookie) 6862306a36Sopenharmony_ci{ 6962306a36Sopenharmony_ci struct virt_dma_desc *vd; 7062306a36Sopenharmony_ci 7162306a36Sopenharmony_ci list_for_each_entry(vd, &vc->desc_issued, node) 7262306a36Sopenharmony_ci if (vd->tx.cookie == cookie) 7362306a36Sopenharmony_ci return vd; 7462306a36Sopenharmony_ci 7562306a36Sopenharmony_ci return NULL; 7662306a36Sopenharmony_ci} 7762306a36Sopenharmony_ciEXPORT_SYMBOL_GPL(vchan_find_desc); 7862306a36Sopenharmony_ci 7962306a36Sopenharmony_ci/* 8062306a36Sopenharmony_ci * This tasklet handles the completion of a DMA descriptor by 8162306a36Sopenharmony_ci * calling its callback and freeing it. 8262306a36Sopenharmony_ci */ 8362306a36Sopenharmony_cistatic void vchan_complete(struct tasklet_struct *t) 8462306a36Sopenharmony_ci{ 8562306a36Sopenharmony_ci struct virt_dma_chan *vc = from_tasklet(vc, t, task); 8662306a36Sopenharmony_ci struct virt_dma_desc *vd, *_vd; 8762306a36Sopenharmony_ci struct dmaengine_desc_callback cb; 8862306a36Sopenharmony_ci LIST_HEAD(head); 8962306a36Sopenharmony_ci 9062306a36Sopenharmony_ci spin_lock_irq(&vc->lock); 9162306a36Sopenharmony_ci list_splice_tail_init(&vc->desc_completed, &head); 9262306a36Sopenharmony_ci vd = vc->cyclic; 9362306a36Sopenharmony_ci if (vd) { 9462306a36Sopenharmony_ci vc->cyclic = NULL; 9562306a36Sopenharmony_ci dmaengine_desc_get_callback(&vd->tx, &cb); 9662306a36Sopenharmony_ci } else { 9762306a36Sopenharmony_ci memset(&cb, 0, sizeof(cb)); 9862306a36Sopenharmony_ci } 9962306a36Sopenharmony_ci spin_unlock_irq(&vc->lock); 10062306a36Sopenharmony_ci 10162306a36Sopenharmony_ci dmaengine_desc_callback_invoke(&cb, &vd->tx_result); 10262306a36Sopenharmony_ci 10362306a36Sopenharmony_ci list_for_each_entry_safe(vd, _vd, &head, node) { 10462306a36Sopenharmony_ci dmaengine_desc_get_callback(&vd->tx, &cb); 10562306a36Sopenharmony_ci 10662306a36Sopenharmony_ci list_del(&vd->node); 10762306a36Sopenharmony_ci dmaengine_desc_callback_invoke(&cb, &vd->tx_result); 10862306a36Sopenharmony_ci vchan_vdesc_fini(vd); 10962306a36Sopenharmony_ci } 11062306a36Sopenharmony_ci} 11162306a36Sopenharmony_ci 11262306a36Sopenharmony_civoid vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head) 11362306a36Sopenharmony_ci{ 11462306a36Sopenharmony_ci struct virt_dma_desc *vd, *_vd; 11562306a36Sopenharmony_ci 11662306a36Sopenharmony_ci list_for_each_entry_safe(vd, _vd, head, node) { 11762306a36Sopenharmony_ci list_del(&vd->node); 11862306a36Sopenharmony_ci vchan_vdesc_fini(vd); 11962306a36Sopenharmony_ci } 12062306a36Sopenharmony_ci} 12162306a36Sopenharmony_ciEXPORT_SYMBOL_GPL(vchan_dma_desc_free_list); 12262306a36Sopenharmony_ci 12362306a36Sopenharmony_civoid vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev) 12462306a36Sopenharmony_ci{ 12562306a36Sopenharmony_ci dma_cookie_init(&vc->chan); 12662306a36Sopenharmony_ci 12762306a36Sopenharmony_ci spin_lock_init(&vc->lock); 12862306a36Sopenharmony_ci INIT_LIST_HEAD(&vc->desc_allocated); 12962306a36Sopenharmony_ci INIT_LIST_HEAD(&vc->desc_submitted); 13062306a36Sopenharmony_ci INIT_LIST_HEAD(&vc->desc_issued); 13162306a36Sopenharmony_ci INIT_LIST_HEAD(&vc->desc_completed); 13262306a36Sopenharmony_ci INIT_LIST_HEAD(&vc->desc_terminated); 13362306a36Sopenharmony_ci 13462306a36Sopenharmony_ci tasklet_setup(&vc->task, vchan_complete); 13562306a36Sopenharmony_ci 13662306a36Sopenharmony_ci vc->chan.device = dmadev; 13762306a36Sopenharmony_ci list_add_tail(&vc->chan.device_node, &dmadev->channels); 13862306a36Sopenharmony_ci} 13962306a36Sopenharmony_ciEXPORT_SYMBOL_GPL(vchan_init); 14062306a36Sopenharmony_ci 14162306a36Sopenharmony_ciMODULE_AUTHOR("Russell King"); 14262306a36Sopenharmony_ciMODULE_LICENSE("GPL"); 143