From 9c4d1e7bdeb1ed4dc0c3341d40662a6fbc5f2dc2 Mon Sep 17 00:00:00 2001 From: Ira Snyder Date: Thu, 3 Mar 2011 07:54:59 +0000 Subject: fsldma: support async_tx dependencies and automatic unmapping Previous to this patch, the dma_run_dependencies() function has been called while holding desc_lock. This function can call tx_submit() for other descriptors, which may try to re-grab the lock. Avoid this by moving the descriptors to be cleaned up to a temporary list, and dropping the lock before cleanup. At the same time, add support for automatic unmapping of src and dst buffers, as offered by the DMAEngine API. Signed-off-by: Ira W. Snyder Signed-off-by: Dan Williams --- drivers/dma/fsldma.c | 131 +++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 95 insertions(+), 36 deletions(-) (limited to 'drivers/dma/fsldma.c') diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 6e9ad6edc4a..526579df603 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -83,6 +83,11 @@ static void set_desc_cnt(struct fsldma_chan *chan, hw->count = CPU_TO_DMA(chan, count, 32); } +static u32 get_desc_cnt(struct fsldma_chan *chan, struct fsl_desc_sw *desc) +{ + return DMA_TO_CPU(chan, desc->hw.count, 32); +} + static void set_desc_src(struct fsldma_chan *chan, struct fsl_dma_ld_hw *hw, dma_addr_t src) { @@ -93,6 +98,16 @@ static void set_desc_src(struct fsldma_chan *chan, hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64); } +static dma_addr_t get_desc_src(struct fsldma_chan *chan, + struct fsl_desc_sw *desc) +{ + u64 snoop_bits; + + snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) + ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0; + return DMA_TO_CPU(chan, desc->hw.src_addr, 64) & ~snoop_bits; +} + static void set_desc_dst(struct fsldma_chan *chan, struct fsl_dma_ld_hw *hw, dma_addr_t dst) { @@ -103,6 +118,16 @@ static void set_desc_dst(struct fsldma_chan *chan, hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64); } +static dma_addr_t get_desc_dst(struct fsldma_chan *chan, + struct fsl_desc_sw *desc) +{ + u64 snoop_bits; + + snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) + ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0; + return DMA_TO_CPU(chan, desc->hw.dst_addr, 64) & ~snoop_bits; +} + static void set_desc_next(struct fsldma_chan *chan, struct fsl_dma_ld_hw *hw, dma_addr_t next) { @@ -805,6 +830,57 @@ static int fsl_dma_device_control(struct dma_chan *dchan, return 0; } +/** + * fsldma_cleanup_descriptor - cleanup and free a single link descriptor + * @chan: Freescale DMA channel + * @desc: descriptor to cleanup and free + * + * This function is used on a descriptor which has been executed by the DMA + * controller. It will run any callbacks, submit any dependencies, and then + * free the descriptor. + */ +static void fsldma_cleanup_descriptor(struct fsldma_chan *chan, + struct fsl_desc_sw *desc) +{ + struct dma_async_tx_descriptor *txd = &desc->async_tx; + struct device *dev = chan->common.device->dev; + dma_addr_t src = get_desc_src(chan, desc); + dma_addr_t dst = get_desc_dst(chan, desc); + u32 len = get_desc_cnt(chan, desc); + + /* Run the link descriptor callback function */ + if (txd->callback) { +#ifdef FSL_DMA_LD_DEBUG + chan_dbg(chan, "LD %p callback\n", desc); +#endif + txd->callback(txd->callback_param); + } + + /* Run any dependencies */ + dma_run_dependencies(txd); + + /* Unmap the dst buffer, if requested */ + if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) { + if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE) + dma_unmap_single(dev, dst, len, DMA_FROM_DEVICE); + else + dma_unmap_page(dev, dst, len, DMA_FROM_DEVICE); + } + + /* Unmap the src buffer, if requested */ + if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) { + if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE) + dma_unmap_single(dev, src, len, DMA_TO_DEVICE); + else + dma_unmap_page(dev, src, len, DMA_TO_DEVICE); + } + +#ifdef FSL_DMA_LD_DEBUG + chan_dbg(chan, "LD %p free\n", desc); +#endif + dma_pool_free(chan->desc_pool, desc, txd->phys); +} + /** * fsl_chan_ld_cleanup - Clean up link descriptors * @chan : Freescale DMA channel @@ -818,56 +894,39 @@ static int fsl_dma_device_control(struct dma_chan *dchan, static void fsl_chan_ld_cleanup(struct fsldma_chan *chan) { struct fsl_desc_sw *desc, *_desc; + LIST_HEAD(ld_cleanup); unsigned long flags; spin_lock_irqsave(&chan->desc_lock, flags); - /* if the ld_running list is empty, there is nothing to do */ - if (list_empty(&chan->ld_running)) { - chan_dbg(chan, "no descriptors to cleanup\n"); - goto out_unlock; + /* update the cookie if we have some descriptors to cleanup */ + if (!list_empty(&chan->ld_running)) { + dma_cookie_t cookie; + + desc = to_fsl_desc(chan->ld_running.prev); + cookie = desc->async_tx.cookie; + + chan->completed_cookie = cookie; + chan_dbg(chan, "completed cookie=%d\n", cookie); } /* - * Get the last descriptor, update the cookie to it - * - * This is done before callbacks run so that clients can check the - * status of their DMA transfer inside the callback. + * move the descriptors to a temporary list so we can drop the lock + * during the entire cleanup operation */ - desc = to_fsl_desc(chan->ld_running.prev); - chan->completed_cookie = desc->async_tx.cookie; - chan_dbg(chan, "completed_cookie = %d\n", chan->completed_cookie); + list_splice_tail_init(&chan->ld_running, &ld_cleanup); + + spin_unlock_irqrestore(&chan->desc_lock, flags); /* Run the callback for each descriptor, in order */ - list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) { - dma_async_tx_callback callback; - void *callback_param; + list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) { - /* Remove from the list of running transactions */ + /* Remove from the list of transactions */ list_del(&desc->node); - /* Run the link descriptor callback function */ - callback = desc->async_tx.callback; - callback_param = desc->async_tx.callback_param; - if (callback) { - spin_unlock_irqrestore(&chan->desc_lock, flags); -#ifdef FSL_DMA_LD_DEBUG - chan_dbg(chan, "LD %p callback\n", desc); -#endif - callback(callback_param); - spin_lock_irqsave(&chan->desc_lock, flags); - } - - /* Run any dependencies, then free the descriptor */ - dma_run_dependencies(&desc->async_tx); -#ifdef FSL_DMA_LD_DEBUG - chan_dbg(chan, "LD %p free\n", desc); -#endif - dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys); + /* Run all cleanup for this descriptor */ + fsldma_cleanup_descriptor(chan, desc); } - -out_unlock: - spin_unlock_irqrestore(&chan->desc_lock, flags); } /** -- cgit v1.2.3-18-g5258