Merge tag 'dmaengine-4.5-rc1' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine updates from Vinod Koul:
 "This round we have few new features, new driver and updates to few
  drivers.

  The new features to dmaengine core are:
   - Synchronized transfer termination API to terminate the dmaengine
     transfers in synchronized and async fashion as required by users.
     We have its user now in ALSA dmaengine lib, img, at_xdma, axi_dmac
     drivers.
   - Universal API for channel request and start consolidation of
     request flows.  It's user is ompa-dma driver.
   - Introduce reuse of descriptors and use in pxa_dma driver

  Add/Remove:
   - New STM32 DMA driver
   - Removal of unused R-Car HPB-DMAC driver

  Updates:
   - ti-dma-crossbar updates for supporting eDMA
   - tegra-apb pm updates
   - idma64
   - mv_xor updates
   - ste_dma updates"

* tag 'dmaengine-4.5-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (54 commits)
  dmaengine: mv_xor: add suspend/resume support
  dmaengine: mv_xor: de-duplicate mv_chan_set_mode*()
  dmaengine: mv_xor: remove mv_xor_chan->current_type field
  dmaengine: omap-dma: Add support for DMA filter mapping to slave devices
  dmaengine: edma: Add support for DMA filter mapping to slave devices
  dmaengine: core: Introduce new, universal API to request a channel
  dmaengine: core: Move and merge the code paths using private_candidate
  dmaengine: core: Skip mask matching when it is not provided to private_candidate
  dmaengine: mdc: Correct terminate_all handling
  dmaengine: edma: Add probe callback to edma_tptc_driver
  dmaengine: dw: fix potential memory leak in dw_dma_parse_dt()
  dmaengine: stm32-dma: Fix unchecked deference of chan->desc
  dmaengine: sh: Remove unused R-Car HPB-DMAC driver
  dmaengine: usb-dmac: Document SoC specific compatibility strings
  ste_dma40: Delete an unnecessary variable initialisation in d40_probe()
  ste_dma40: Delete another unnecessary check in d40_probe()
  ste_dma40: Delete an unnecessary check before the function call "kmem_cache_destroy"
  dmaengine: tegra-apb: Free interrupts before killing tasklets
  dmaengine: tegra-apb: Update driver to use GFP_NOWAIT
  dmaengine: tegra-apb: Only save channel state for those in use
  ...

1 files changed, 40 insertions, 6 deletions

diff --git a/drivers/dma/virt-dma.c b/drivers/dma/virt-dma.c
index 6f80432a3f0a..a35c211857dd 100644
--- a/drivers/dma/virt-dma.c
+++ b/drivers/dma/virt-dma.c
@@ -29,7 +29,7 @@ dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx)
 	spin_lock_irqsave(&vc->lock, flags);
 	cookie = dma_cookie_assign(tx);
 
-	list_add_tail(&vd->node, &vc->desc_submitted);
+	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",
@@ -39,6 +39,33 @@ dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx)
 }
 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;
+}
+EXPORT_SYMBOL_GPL(vchan_tx_desc_free);
+
 struct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *vc,
 	dma_cookie_t cookie)
 {
@@ -83,8 +110,10 @@ static void vchan_complete(unsigned long arg)
 		cb_data = vd->tx.callback_param;
 
 		list_del(&vd->node);
-
-		vc->desc_free(vd);
+		if (dmaengine_desc_test_reuse(&vd->tx))
+			list_add(&vd->node, &vc->desc_allocated);
+		else
+			vc->desc_free(vd);
 
 		if (cb)
 			cb(cb_data);
@@ -96,9 +125,13 @@ 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);
-		list_del(&vd->node);
-		dev_dbg(vc->chan.device->dev, "txd %p: freeing\n", vd);
-		vc->desc_free(vd);
+		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);
+		}
 	}
 }
 EXPORT_SYMBOL_GPL(vchan_dma_desc_free_list);
@@ -108,6 +141,7 @@ 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);