diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index 435d7daa1c0f..d3a63c866645 100644 --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -217,6 +217,10 @@ struct sun6i_dma_dev { struct clk *clk; struct clk *clk_mbus; int irq; + /* + * Physical channels, pending list and registers; nests outside vc.lock. + * virt-dma also takes vc.lock independently for its lists and cookies. + */ spinlock_t lock; struct reset_control *rstc; struct tasklet_struct task; @@ -524,11 +528,11 @@ static void sun6i_dma_tasklet(struct tasklet_struct *t) struct sun6i_dma_dev *sdev = from_tasklet(sdev, t, task); struct sun6i_vchan *vchan; struct sun6i_pchan *pchan; - unsigned int pchan_alloc = 0; unsigned int pchan_idx; + spin_lock_irq(&sdev->lock); list_for_each_entry(vchan, &sdev->slave.channels, vc.chan.device_node) { - spin_lock_irq(&vchan->vc.lock); + spin_lock(&vchan->vc.lock); pchan = vchan->phy; @@ -545,10 +549,9 @@ static void sun6i_dma_tasklet(struct tasklet_struct *t) pchan->vchan = NULL; } } - spin_unlock_irq(&vchan->vc.lock); + spin_unlock(&vchan->vc.lock); } - spin_lock_irq(&sdev->lock); for (pchan_idx = 0; pchan_idx < sdev->num_pchans; pchan_idx++) { pchan = &sdev->pchans[pchan_idx]; @@ -557,31 +560,20 @@ static void sun6i_dma_tasklet(struct tasklet_struct *t) vchan = list_first_entry(&sdev->pending, struct sun6i_vchan, node); + spin_lock(&vchan->vc.lock); /* Remove from pending channels */ list_del_init(&vchan->node); - pchan_alloc |= BIT(pchan_idx); /* Mark this channel allocated */ pchan->vchan = vchan; vchan->phy = pchan; dev_dbg(sdev->slave.dev, "pchan %u: alloc vchan %p\n", pchan->idx, &vchan->vc); + sun6i_dma_start_desc(vchan); + spin_unlock(&vchan->vc.lock); } spin_unlock_irq(&sdev->lock); - - for (pchan_idx = 0; pchan_idx < sdev->num_pchans; pchan_idx++) { - if (!(pchan_alloc & BIT(pchan_idx))) - continue; - - pchan = sdev->pchans + pchan_idx; - vchan = pchan->vchan; - if (vchan) { - spin_lock_irq(&vchan->vc.lock); - sun6i_dma_start_desc(vchan); - spin_unlock_irq(&vchan->vc.lock); - } - } } static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id) @@ -590,9 +582,11 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id) u32 channels_per_reg = sdev->cfg->num_channels_per_reg; struct sun6i_vchan *vchan; struct sun6i_pchan *pchan; + unsigned long flags; int i, j, ret = IRQ_NONE; u32 status; + spin_lock_irqsave(&sdev->lock, flags); for (i = 0; i < DIV_ROUND_UP(sdev->num_pchans, channels_per_reg); i++) { status = sun6i_read_irq_stat(sdev, i); if (!status) @@ -608,14 +602,14 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id) pchan = sdev->pchans + i * channels_per_reg + j; vchan = pchan->vchan; if (vchan && (status & vchan->irq_type)) { + spin_lock(&vchan->vc.lock); if (vchan->cyclic) { vchan_cyclic_callback(&pchan->desc->vd); } else { - spin_lock(&vchan->vc.lock); vchan_cookie_complete(&pchan->desc->vd); pchan->done = pchan->desc; - spin_unlock(&vchan->vc.lock); } + spin_unlock(&vchan->vc.lock); } status = status >> DMA_IRQ_CHAN_WIDTH; @@ -625,6 +619,7 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id) tasklet_schedule(&sdev->task); ret = IRQ_HANDLED; } + spin_unlock_irqrestore(&sdev->lock, flags); return ret; } @@ -931,19 +926,20 @@ static int sun6i_dma_pause(struct dma_chan *chan) { struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device); struct sun6i_vchan *vchan = to_sun6i_vchan(chan); - struct sun6i_pchan *pchan = vchan->phy; + struct sun6i_pchan *pchan; unsigned long flags; dev_dbg(dmaengine_chan_dev(chan), "vchan %p: pause\n", &vchan->vc); + spin_lock_irqsave(&sdev->lock, flags); + pchan = vchan->phy; if (pchan) { writel(DMA_CHAN_PAUSE_PAUSE, pchan->base + DMA_CHAN_PAUSE); } else { - spin_lock_irqsave(&sdev->lock, flags); list_del_init(&vchan->node); - spin_unlock_irqrestore(&sdev->lock, flags); } + spin_unlock_irqrestore(&sdev->lock, flags); return 0; } @@ -978,15 +974,14 @@ static int sun6i_dma_terminate_all(struct dma_chan *chan) { struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device); struct sun6i_vchan *vchan = to_sun6i_vchan(chan); - struct sun6i_pchan *pchan = vchan->phy; + struct sun6i_pchan *pchan; unsigned long flags; LIST_HEAD(head); spin_lock_irqsave(&sdev->lock, flags); + spin_lock(&vchan->vc.lock); + pchan = vchan->phy; list_del_init(&vchan->node); - spin_unlock_irqrestore(&sdev->lock, flags); - - spin_lock_irqsave(&vchan->vc.lock, flags); if (pchan && pchan->desc && pchan->desc != pchan->done) { struct virt_dma_desc *vd = &pchan->desc->vd; @@ -1007,7 +1002,8 @@ static int sun6i_dma_terminate_all(struct dma_chan *chan) pchan->done = NULL; } - spin_unlock_irqrestore(&vchan->vc.lock, flags); + spin_unlock(&vchan->vc.lock); + spin_unlock_irqrestore(&sdev->lock, flags); vchan_dma_desc_free_list(&vchan->vc, &head); @@ -1018,8 +1014,9 @@ static enum dma_status sun6i_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *state) { + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device); struct sun6i_vchan *vchan = to_sun6i_vchan(chan); - struct sun6i_pchan *pchan = vchan->phy; + struct sun6i_pchan *pchan; struct sun6i_dma_lli *lli; struct virt_dma_desc *vd; struct sun6i_desc *txd; @@ -1027,11 +1024,12 @@ static enum dma_status sun6i_dma_tx_status(struct dma_chan *chan, unsigned long flags; size_t bytes = 0; + spin_lock_irqsave(&sdev->lock, flags); + spin_lock(&vchan->vc.lock); ret = dma_cookie_status(chan, cookie, state); if (ret == DMA_COMPLETE || !state) - return ret; - - spin_lock_irqsave(&vchan->vc.lock, flags); + goto out; + pchan = vchan->phy; vd = vchan_find_desc(&vchan->vc, cookie); txd = to_sun6i_desc(&vd->tx); @@ -1045,9 +1043,10 @@ static enum dma_status sun6i_dma_tx_status(struct dma_chan *chan, bytes = sun6i_get_chan_size(pchan); } - spin_unlock_irqrestore(&vchan->vc.lock, flags); - dma_set_residue(state, bytes); +out: + spin_unlock(&vchan->vc.lock); + spin_unlock_irqrestore(&sdev->lock, flags); return ret; }