Merge branch 'akpm' (Andrew's patch-bomb)

Merge misc patches from Andrew Morton:

 - the "misc" tree - stuff from all over the map

 - checkpatch updates

 - fatfs

 - kmod changes

 - procfs

 - cpumask

 - UML

 - kexec

 - mqueue

 - rapidio

 - pidns

 - some checkpoint-restore feature work.  Reluctantly.  Most of it
   delayed a release.  I'm still rather worried that we don't have a
   clear roadmap to completion for this work.

* emailed from Andrew Morton <akpm@linux-foundation.org>: (78 patches)
  kconfig: update compression algorithm info
  c/r: prctl: add ability to set new mm_struct::exe_file
  c/r: prctl: extend PR_SET_MM to set up more mm_struct entries
  c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat
  syscalls, x86: add __NR_kcmp syscall
  fs, proc: introduce /proc/<pid>/task/<tid>/children entry
  sysctl: make kernel.ns_last_pid control dependent on CHECKPOINT_RESTORE
  aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
  eventfd: change int to __u64 in eventfd_signal()
  fs/nls: add Apple NLS
  pidns: make killed children autoreap
  pidns: use task_active_pid_ns in do_notify_parent
  rapidio/tsi721: add DMA engine support
  rapidio: add DMA engine support for RIO data transfers
  ipc/mqueue: add rbtree node caching support
  tools/selftests: add mq_perf_tests
  ipc/mqueue: strengthen checks on mqueue creation
  ipc/mqueue: correct mq_attr_ok test
  ipc/mqueue: improve performance of send/recv
  selftests: add mq_open_tests
  ...

8 files changed, 1150 insertions, 103 deletions

diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c
index 444143e5f28c..d99db5623acf 100644
--- a/drivers/message/fusion/mptbase.c
+++ b/drivers/message/fusion/mptbase.c
@@ -1653,7 +1653,6 @@ mpt_mapresources(MPT_ADAPTER *ioc)
 	unsigned long	 port;
 	u32		 msize;
 	u32		 psize;
-	u8		 revision;
 	int		 r = -ENODEV;
 	struct pci_dev *pdev;
 
@@ -1670,8 +1669,6 @@ mpt_mapresources(MPT_ADAPTER *ioc)
 		return r;
 	}
 
-	pci_read_config_byte(pdev, PCI_CLASS_REVISION, &revision);
-
 	if (sizeof(dma_addr_t) > 4) {
 		const uint64_t required_mask = dma_get_required_mask
 		    (&pdev->dev);
@@ -1779,7 +1776,6 @@ mpt_attach(struct pci_dev *pdev, const struct pci_device_id *id)
 	MPT_ADAPTER	*ioc;
 	u8		 cb_idx;
 	int		 r = -ENODEV;
-	u8		 revision;
 	u8		 pcixcmd;
 	static int	 mpt_ids = 0;
 #ifdef CONFIG_PROC_FS
@@ -1887,8 +1883,8 @@ mpt_attach(struct pci_dev *pdev, const struct pci_device_id *id)
 	dinitprintk(ioc, printk(MYIOC_s_INFO_FMT "facts @ %p, pfacts[0] @ %p\n",
 	    ioc->name, &ioc->facts, &ioc->pfacts[0]));
 
-	pci_read_config_byte(pdev, PCI_CLASS_REVISION, &revision);
-	mpt_get_product_name(pdev->vendor, pdev->device, revision, ioc->prod_name);
+	mpt_get_product_name(pdev->vendor, pdev->device, pdev->revision,
+			     ioc->prod_name);
 
 	switch (pdev->device)
 	{
@@ -1903,7 +1899,7 @@ mpt_attach(struct pci_dev *pdev, const struct pci_device_id *id)
 		break;
 
 	case MPI_MANUFACTPAGE_DEVICEID_FC929X:
-		if (revision < XL_929) {
+		if (pdev->revision < XL_929) {
 			/* 929X Chip Fix. Set Split transactions level
 		 	* for PCIX. Set MOST bits to zero.
 		 	*/
@@ -1934,7 +1930,7 @@ mpt_attach(struct pci_dev *pdev, const struct pci_device_id *id)
 		/* 1030 Chip Fix. Disable Split transactions
 		 * for PCIX. Set MOST bits to zero if Rev < C0( = 8).
 		 */
-		if (revision < C0_1030) {
+		if (pdev->revision < C0_1030) {
 			pci_read_config_byte(pdev, 0x6a, &pcixcmd);
 			pcixcmd &= 0x8F;
 			pci_write_config_byte(pdev, 0x6a, pcixcmd);
diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c
index 6e6e16aab9da..b383b6961e59 100644
--- a/drivers/message/fusion/mptctl.c
+++ b/drivers/message/fusion/mptctl.c
@@ -1250,7 +1250,6 @@ mptctl_getiocinfo (unsigned long arg, unsigned int data_size)
 	int			iocnum;
 	unsigned int		port;
 	int			cim_rev;
-	u8			revision;
 	struct scsi_device 	*sdev;
 	VirtDevice		*vdevice;
 
@@ -1324,8 +1323,7 @@ mptctl_getiocinfo (unsigned long arg, unsigned int data_size)
 	pdev = (struct pci_dev *) ioc->pcidev;
 
 	karg->pciId = pdev->device;
-	pci_read_config_byte(pdev, PCI_CLASS_REVISION, &revision);
-	karg->hwRev = revision;
+	karg->hwRev = pdev->revision;
 	karg->subSystemDevice = pdev->subsystem_device;
 	karg->subSystemVendor = pdev->subsystem_vendor;
 
diff --git a/drivers/rapidio/Kconfig b/drivers/rapidio/Kconfig
index bc8719238793..6194d35ebb97 100644
--- a/drivers/rapidio/Kconfig
+++ b/drivers/rapidio/Kconfig
@@ -22,6 +22,20 @@ config RAPIDIO_ENABLE_RX_TX_PORTS
 	  ports for Input/Output direction to allow other traffic
 	  than Maintenance transfers.
 
+config RAPIDIO_DMA_ENGINE
+	bool "DMA Engine support for RapidIO"
+	depends on RAPIDIO
+	select DMADEVICES
+	select DMA_ENGINE
+	help
+	  Say Y here if you want to use DMA Engine frameork for RapidIO data
+	  transfers to/from target RIO devices. RapidIO uses NREAD and
+	  NWRITE (NWRITE_R, SWRITE) requests to transfer data between local
+	  memory and memory on remote target device. You need a DMA controller
+	  capable to perform data transfers to/from RapidIO.
+
+	  If you are unsure about this, say Y here.
+
 config RAPIDIO_DEBUG
 	bool "RapidIO subsystem debug messages"
 	depends on RAPIDIO
diff --git a/drivers/rapidio/devices/Makefile b/drivers/rapidio/devices/Makefile
index 3b7b4e2dff7c..7b62860f34f8 100644
--- a/drivers/rapidio/devices/Makefile
+++ b/drivers/rapidio/devices/Makefile
@@ -3,3 +3,6 @@
 #
 
 obj-$(CONFIG_RAPIDIO_TSI721)	+= tsi721.o
+ifeq ($(CONFIG_RAPIDIO_DMA_ENGINE),y)
+obj-$(CONFIG_RAPIDIO_TSI721)	+= tsi721_dma.o
+endif
diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index 30d2072f480b..722246cf20ab 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -108,6 +108,7 @@ static int tsi721_maint_dma(struct tsi721_device *priv, u32 sys_size,
 			u16 destid, u8 hopcount, u32 offset, int len,
 			u32 *data, int do_wr)
 {
+	void __iomem *regs = priv->regs + TSI721_DMAC_BASE(priv->mdma.ch_id);
 	struct tsi721_dma_desc *bd_ptr;
 	u32 rd_count, swr_ptr, ch_stat;
 	int i, err = 0;
@@ -116,10 +117,9 @@ static int tsi721_maint_dma(struct tsi721_device *priv, u32 sys_size,
 	if (offset > (RIO_MAINT_SPACE_SZ - len) || (len != sizeof(u32)))
 		return -EINVAL;
 
-	bd_ptr = priv->bdma[TSI721_DMACH_MAINT].bd_base;
+	bd_ptr = priv->mdma.bd_base;
 
-	rd_count = ioread32(
-			priv->regs + TSI721_DMAC_DRDCNT(TSI721_DMACH_MAINT));
+	rd_count = ioread32(regs + TSI721_DMAC_DRDCNT);
 
 	/* Initialize DMA descriptor */
 	bd_ptr[0].type_id = cpu_to_le32((DTYPE2 << 29) | (op << 19) | destid);
@@ -134,19 +134,18 @@ static int tsi721_maint_dma(struct tsi721_device *priv, u32 sys_size,
 	mb();
 
 	/* Start DMA operation */
-	iowrite32(rd_count + 2,
-		priv->regs + TSI721_DMAC_DWRCNT(TSI721_DMACH_MAINT));
-	ioread32(priv->regs + TSI721_DMAC_DWRCNT(TSI721_DMACH_MAINT));
+	iowrite32(rd_count + 2,	regs + TSI721_DMAC_DWRCNT);
+	ioread32(regs + TSI721_DMAC_DWRCNT);
 	i = 0;
 
 	/* Wait until DMA transfer is finished */
-	while ((ch_stat = ioread32(priv->regs +
-		TSI721_DMAC_STS(TSI721_DMACH_MAINT))) & TSI721_DMAC_STS_RUN) {
+	while ((ch_stat = ioread32(regs + TSI721_DMAC_STS))
+							& TSI721_DMAC_STS_RUN) {
 		udelay(1);
 		if (++i >= 5000000) {
 			dev_dbg(&priv->pdev->dev,
 				"%s : DMA[%d] read timeout ch_status=%x\n",
-				__func__, TSI721_DMACH_MAINT, ch_stat);
+				__func__, priv->mdma.ch_id, ch_stat);
 			if (!do_wr)
 				*data = 0xffffffff;
 			err = -EIO;
@@ -162,13 +161,10 @@ static int tsi721_maint_dma(struct tsi721_device *priv, u32 sys_size,
 			__func__, ch_stat);
 		dev_dbg(&priv->pdev->dev, "OP=%d : destid=%x hc=%x off=%x\n",
 			do_wr ? MAINT_WR : MAINT_RD, destid, hopcount, offset);
-		iowrite32(TSI721_DMAC_INT_ALL,
-			priv->regs + TSI721_DMAC_INT(TSI721_DMACH_MAINT));
-		iowrite32(TSI721_DMAC_CTL_INIT,
-			priv->regs + TSI721_DMAC_CTL(TSI721_DMACH_MAINT));
+		iowrite32(TSI721_DMAC_INT_ALL, regs + TSI721_DMAC_INT);
+		iowrite32(TSI721_DMAC_CTL_INIT, regs + TSI721_DMAC_CTL);
 		udelay(10);
-		iowrite32(0, priv->regs +
-				TSI721_DMAC_DWRCNT(TSI721_DMACH_MAINT));
+		iowrite32(0, regs + TSI721_DMAC_DWRCNT);
 		udelay(1);
 		if (!do_wr)
 			*data = 0xffffffff;
@@ -184,8 +180,8 @@ static int tsi721_maint_dma(struct tsi721_device *priv, u32 sys_size,
 	 * NOTE: Skipping check and clear FIFO entries because we are waiting
 	 * for transfer to be completed.
 	 */
-	swr_ptr = ioread32(priv->regs + TSI721_DMAC_DSWP(TSI721_DMACH_MAINT));
-	iowrite32(swr_ptr, priv->regs + TSI721_DMAC_DSRP(TSI721_DMACH_MAINT));
+	swr_ptr = ioread32(regs + TSI721_DMAC_DSWP);
+	iowrite32(swr_ptr, regs + TSI721_DMAC_DSRP);
 err_out:
 
 	return err;
@@ -541,6 +537,22 @@ static irqreturn_t tsi721_irqhandler(int irq, void *ptr)
 			tsi721_pw_handler(mport);
 	}
 
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+	if (dev_int & TSI721_DEV_INT_BDMA_CH) {
+		int ch;
+
+		if (dev_ch_int & TSI721_INT_BDMA_CHAN_M) {
+			dev_dbg(&priv->pdev->dev,
+				"IRQ from DMA channel 0x%08x\n", dev_ch_int);
+
+			for (ch = 0; ch < TSI721_DMA_MAXCH; ch++) {
+				if (!(dev_ch_int & TSI721_INT_BDMA_CHAN(ch)))
+					continue;
+				tsi721_bdma_handler(&priv->bdma[ch]);
+			}
+		}
+	}
+#endif
 	return IRQ_HANDLED;
 }
 
@@ -553,18 +565,26 @@ static void tsi721_interrupts_init(struct tsi721_device *priv)
 		priv->regs + TSI721_SR_CHINT(IDB_QUEUE));
 	iowrite32(TSI721_SR_CHINT_IDBQRCV,
 		priv->regs + TSI721_SR_CHINTE(IDB_QUEUE));
-	iowrite32(TSI721_INT_SR2PC_CHAN(IDB_QUEUE),
-		priv->regs + TSI721_DEV_CHAN_INTE);
 
 	/* Enable SRIO MAC interrupts */
 	iowrite32(TSI721_RIO_EM_DEV_INT_EN_INT,
 		priv->regs + TSI721_RIO_EM_DEV_INT_EN);
 
+	/* Enable interrupts from channels in use */
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+	intr = TSI721_INT_SR2PC_CHAN(IDB_QUEUE) |
+		(TSI721_INT_BDMA_CHAN_M &
+		 ~TSI721_INT_BDMA_CHAN(TSI721_DMACH_MAINT));
+#else
+	intr = TSI721_INT_SR2PC_CHAN(IDB_QUEUE);
+#endif
+	iowrite32(intr,	priv->regs + TSI721_DEV_CHAN_INTE);
+
 	if (priv->flags & TSI721_USING_MSIX)
 		intr = TSI721_DEV_INT_SRIO;
 	else
 		intr = TSI721_DEV_INT_SR2PC_CH | TSI721_DEV_INT_SRIO |
-			TSI721_DEV_INT_SMSG_CH;
+			TSI721_DEV_INT_SMSG_CH | TSI721_DEV_INT_BDMA_CH;
 
 	iowrite32(intr, priv->regs + TSI721_DEV_INTE);
 	ioread32(priv->regs + TSI721_DEV_INTE);
@@ -715,12 +735,29 @@ static int tsi721_enable_msix(struct tsi721_device *priv)
 					TSI721_MSIX_OMSG_INT(i);
 	}
 
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+	/*
+	 * Initialize MSI-X entries for Block DMA Engine:
+	 * this driver supports XXX DMA channels
+	 * (one is reserved for SRIO maintenance transactions)
+	 */
+	for (i = 0; i < TSI721_DMA_CHNUM; i++) {
+		entries[TSI721_VECT_DMA0_DONE + i].entry =
+					TSI721_MSIX_DMACH_DONE(i);
+		entries[TSI721_VECT_DMA0_INT + i].entry =
+					TSI721_MSIX_DMACH_INT(i);
+	}
+#endif /* CONFIG_RAPIDIO_DMA_ENGINE */
+
 	err = pci_enable_msix(priv->pdev, entries, ARRAY_SIZE(entries));
 	if (err) {
 		if (err > 0)
 			dev_info(&priv->pdev->dev,
 				 "Only %d MSI-X vectors available, "
 				 "not using MSI-X\n", err);
+		else
+			dev_err(&priv->pdev->dev,
+				"Failed to enable MSI-X (err=%d)\n", err);
 		return err;
 	}
 
@@ -760,6 +797,22 @@ static int tsi721_enable_msix(struct tsi721_device *priv)
 			 i, pci_name(priv->pdev));
 	}
 
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+	for (i = 0; i < TSI721_DMA_CHNUM; i++) {
+		priv->msix[TSI721_VECT_DMA0_DONE + i].vector =
+				entries[TSI721_VECT_DMA0_DONE + i].vector;
+		snprintf(priv->msix[TSI721_VECT_DMA0_DONE + i].irq_name,
+			 IRQ_DEVICE_NAME_MAX, DRV_NAME "-dmad%d@pci:%s",
+			 i, pci_name(priv->pdev));
+
+		priv->msix[TSI721_VECT_DMA0_INT + i].vector =
+				entries[TSI721_VECT_DMA0_INT + i].vector;
+		snprintf(priv->msix[TSI721_VECT_DMA0_INT + i].irq_name,
+			 IRQ_DEVICE_NAME_MAX, DRV_NAME "-dmai%d@pci:%s",
+			 i, pci_name(priv->pdev));
+	}
+#endif /* CONFIG_RAPIDIO_DMA_ENGINE */
+
 	return 0;
 }
 #endif /* CONFIG_PCI_MSI */
@@ -888,20 +941,34 @@ static void tsi721_doorbell_free(struct tsi721_device *priv)
 	priv->idb_base = NULL;
 }
 
-static int tsi721_bdma_ch_init(struct tsi721_device *priv, int chnum)
+/**
+ * tsi721_bdma_maint_init - Initialize maintenance request BDMA channel.
+ * @priv: pointer to tsi721 private data
+ *
+ * Initialize BDMA channel allocated for RapidIO maintenance read/write
+ * request generation
+ * Returns %0 on success or %-ENOMEM on failure.
+ */
+static int tsi721_bdma_maint_init(struct tsi721_device *priv)
 {
 	struct tsi721_dma_desc *bd_ptr;
 	u64		*sts_ptr;
 	dma_addr_t	bd_phys, sts_phys;
 	int		sts_size;
-	int		bd_num = priv->bdma[chnum].bd_num;
+	int		bd_num = 2;
+	void __iomem	*regs;
 
-	dev_dbg(&priv->pdev->dev, "Init Block DMA Engine, CH%d\n", chnum);
+	dev_dbg(&priv->pdev->dev,
+		"Init Block DMA Engine for Maintenance requests, CH%d\n",
+		TSI721_DMACH_MAINT);
 
 	/*
 	 * Initialize DMA channel for maintenance requests
 	 */
 
+	priv->mdma.ch_id = TSI721_DMACH_MAINT;
+	regs = priv->regs + TSI721_DMAC_BASE(TSI721_DMACH_MAINT);
+
 	/* Allocate space for DMA descriptors */
 	bd_ptr = dma_zalloc_coherent(&priv->pdev->dev,
 					bd_num * sizeof(struct tsi721_dma_desc),
@@ -909,8 +976,9 @@ static int tsi721_bdma_ch_init(struct tsi721_device *priv, int chnum)
 	if (!bd_ptr)
 		return -ENOMEM;
 
-	priv->bdma[chnum].bd_phys = bd_phys;
-	priv->bdma[chnum].bd_base = bd_ptr;
+	priv->mdma.bd_num = bd_num;
+	priv->mdma.bd_phys = bd_phys;
+	priv->mdma.bd_base = bd_ptr;
 
 	dev_dbg(&priv->pdev->dev, "DMA descriptors @ %p (phys = %llx)\n",
 		bd_ptr, (unsigned long long)bd_phys);
@@ -927,13 +995,13 @@ static int tsi721_bdma_ch_init(struct tsi721_device *priv, int chnum)
 		dma_free_coherent(&priv->pdev->dev,
 				  bd_num * sizeof(struct tsi721_dma_desc),
 				  bd_ptr, bd_phys);
-		priv->bdma[chnum].bd_base = NULL;
+		priv->mdma.bd_base = NULL;
 		return -ENOMEM;
 	}
 
-	priv->bdma[chnum].sts_phys = sts_phys;
-	priv->bdma[chnum].sts_base = sts_ptr;
-	priv->bdma[chnum].sts_size = sts_size;
+	priv->mdma.sts_phys = sts_phys;
+	priv->mdma.sts_base = sts_ptr;
+	priv->mdma.sts_size = sts_size;
 
 	dev_dbg(&priv->pdev->dev,
 		"desc status FIFO @ %p (phys = %llx) size=0x%x\n",
@@ -946,83 +1014,61 @@ static int tsi721_bdma_ch_init(struct tsi721_device *priv, int chnum)
 	bd_ptr[bd_num - 1].next_hi = cpu_to_le32((u64)bd_phys >> 32);
 
 	/* Setup DMA descriptor pointers */
-	iowrite32(((u64)bd_phys >> 32),
-		priv->regs + TSI721_DMAC_DPTRH(chnum));
+	iowrite32(((u64)bd_phys >> 32),	regs + TSI721_DMAC_DPTRH);
 	iowrite32(((u64)bd_phys & TSI721_DMAC_DPTRL_MASK),
-		priv->regs + TSI721_DMAC_DPTRL(chnum));
+		regs + TSI721_DMAC_DPTRL);
 
 	/* Setup descriptor status FIFO */
-	iowrite32(((u64)sts_phys >> 32),
-		priv->regs + TSI721_DMAC_DSBH(chnum));
+	iowrite32(((u64)sts_phys >> 32), regs + TSI721_DMAC_DSBH);
 	iowrite32(((u64)sts_phys & TSI721_DMAC_DSBL_MASK),
-		priv->regs + TSI721_DMAC_DSBL(chnum));
+		regs + TSI721_DMAC_DSBL);
 	iowrite32(TSI721_DMAC_DSSZ_SIZE(sts_size),
-		priv->regs + TSI721_DMAC_DSSZ(chnum));
+		regs + TSI721_DMAC_DSSZ);
 
 	/* Clear interrupt bits */
-	iowrite32(TSI721_DMAC_INT_ALL,
-		priv->regs + TSI721_DMAC_INT(chnum));
+	iowrite32(TSI721_DMAC_INT_ALL, regs + TSI721_DMAC_INT);
 
-	ioread32(priv->regs + TSI721_DMAC_INT(chnum));
+	ioread32(regs + TSI721_DMAC_INT);
 
 	/* Toggle DMA channel initialization */
-	iowrite32(TSI721_DMAC_CTL_INIT,	priv->regs + TSI721_DMAC_CTL(chnum));
-	ioread32(priv->regs + TSI721_DMAC_CTL(chnum));
+	iowrite32(TSI721_DMAC_CTL_INIT,	regs + TSI721_DMAC_CTL);
+	ioread32(regs + TSI721_DMAC_CTL);
 	udelay(10);
 
 	return 0;
 }
 
-static int tsi721_bdma_ch_free(struct tsi721_device *priv, int chnum)
+static int tsi721_bdma_maint_free(struct tsi721_device *priv)
 {
 	u32 ch_stat;
+	struct tsi721_bdma_maint *mdma = &priv->mdma;
+	void __iomem *regs = priv->regs + TSI721_DMAC_BASE(mdma->ch_id);
 
-	if (priv->bdma[chnum].bd_base == NULL)
+	if (mdma->bd_base == NULL)
 		return 0;
 
 	/* Check if DMA channel still running */
-	ch_stat = ioread32(priv->regs +	TSI721_DMAC_STS(chnum));
+	ch_stat = ioread32(regs + TSI721_DMAC_STS);
 	if (ch_stat & TSI721_DMAC_STS_RUN)
 		return -EFAULT;
 
 	/* Put DMA channel into init state */
-	iowrite32(TSI721_DMAC_CTL_INIT,
-		priv->regs + TSI721_DMAC_CTL(chnum));
+	iowrite32(TSI721_DMAC_CTL_INIT,	regs + TSI721_DMAC_CTL);
 
 	/* Free space allocated for DMA descriptors */
 	dma_free_coherent(&priv->pdev->dev,
-		priv->bdma[chnum].bd_num * sizeof(struct tsi721_dma_desc),
-		priv->bdma[chnum].bd_base, priv->bdma[chnum].bd_phys);
-	priv->bdma[chnum].bd_base = NULL;
+		mdma->bd_num * sizeof(struct tsi721_dma_desc),
+		mdma->bd_base, mdma->bd_phys);
+	mdma->bd_base = NULL;
 
 	/* Free space allocated for status FIFO */
 	dma_free_coherent(&priv->pdev->dev,
-		priv->bdma[chnum].sts_size * sizeof(struct tsi721_dma_sts),
-		priv->bdma[chnum].sts_base, priv->bdma[chnum].sts_phys);
-	priv->bdma[chnum].sts_base = NULL;
-	return 0;
-}
-
-static int tsi721_bdma_init(struct tsi721_device *priv)
-{
-	/* Initialize BDMA channel allocated for RapidIO maintenance read/write
-	 * request generation
-	 */
-	priv->bdma[TSI721_DMACH_MAINT].bd_num = 2;
-	if (tsi721_bdma_ch_init(priv, TSI721_DMACH_MAINT)) {
-		dev_err(&priv->pdev->dev, "Unable to initialize maintenance DMA"
-			" channel %d, aborting\n", TSI721_DMACH_MAINT);
-		return -ENOMEM;
-	}
-
+		mdma->sts_size * sizeof(struct tsi721_dma_sts),
+		mdma->sts_base, mdma->sts_phys);
+	mdma->sts_base = NULL;
 	return 0;
 }
 
-static void tsi721_bdma_free(struct tsi721_device *priv)
-{
-	tsi721_bdma_ch_free(priv, TSI721_DMACH_MAINT);
-}
-
 /* Enable Inbound Messaging Interrupts */
 static void
 tsi721_imsg_interrupt_enable(struct tsi721_device *priv, int ch,
@@ -2035,7 +2081,8 @@ static void tsi721_disable_ints(struct tsi721_device *priv)
 
 	/* Disable all BDMA Channel interrupts */
 	for (ch = 0; ch < TSI721_DMA_MAXCH; ch++)
-		iowrite32(0, priv->regs + TSI721_DMAC_INTE(ch));
+		iowrite32(0,
+			priv->regs + TSI721_DMAC_BASE(ch) + TSI721_DMAC_INTE);
 
 	/* Disable all general BDMA interrupts */
 	iowrite32(0, priv->regs + TSI721_BDMA_INTE);
@@ -2104,6 +2151,7 @@ static int __devinit tsi721_setup_mport(struct tsi721_device *priv)
 	mport->phy_type = RIO_PHY_SERIAL;
 	mport->priv = (void *)priv;
 	mport->phys_efptr = 0x100;
+	priv->mport = mport;
 
 	INIT_LIST_HEAD(&mport->dbells);
 
@@ -2129,17 +2177,21 @@ static int __devinit tsi721_setup_mport(struct tsi721_device *priv)
 	if (!err) {
 		tsi721_interrupts_init(priv);
 		ops->pwenable = tsi721_pw_enable;
-	} else
+	} else {
 		dev_err(&pdev->dev, "Unable to get assigned PCI IRQ "
 			"vector %02X err=0x%x\n", pdev->irq, err);
+		goto err_exit;
+	}
 
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+	tsi721_register_dma(priv);
+#endif
 	/* Enable SRIO link */
 	iowrite32(ioread32(priv->regs + TSI721_DEVCTL) |
 		  TSI721_DEVCTL_SRBOOT_CMPL,
 		  priv->regs + TSI721_DEVCTL);
 
 	rio_register_mport(mport);
-	priv->mport = mport;
 
 	if (mport->host_deviceid >= 0)
 		iowrite32(RIO_PORT_GEN_HOST | RIO_PORT_GEN_MASTER |
@@ -2149,6 +2201,11 @@ static int __devinit tsi721_setup_mport(struct tsi721_device *priv)
 		iowrite32(0, priv->regs + (0x100 + RIO_PORT_GEN_CTL_CSR));
 
 	return 0;
+
+err_exit:
+	kfree(mport);
+	kfree(ops);
+	return err;
 }
 
 static int __devinit tsi721_probe(struct pci_dev *pdev,
@@ -2294,7 +2351,7 @@ static int __devinit tsi721_probe(struct pci_dev *pdev,
 	tsi721_init_pc2sr_mapping(priv);
 	tsi721_init_sr2pc_mapping(priv);
 
-	if (tsi721_bdma_init(priv)) {
+	if (tsi721_bdma_maint_init(priv)) {
 		dev_err(&pdev->dev, "BDMA initialization failed, aborting\n");
 		err = -ENOMEM;
 		goto err_unmap_bars;
@@ -2319,7 +2376,7 @@ static int __devinit tsi721_probe(struct pci_dev *pdev,
 err_free_consistent:
 	tsi721_doorbell_free(priv);
 err_free_bdma:
-	tsi721_bdma_free(priv);
+	tsi721_bdma_maint_free(priv);
 err_unmap_bars:
 	if (priv->regs)
 		iounmap(priv->regs);
diff --git a/drivers/rapidio/devices/tsi721.h b/drivers/rapidio/devices/tsi721.h
index 1c226b31af13..59de9d7be346 100644
--- a/drivers/rapidio/devices/tsi721.h
+++ b/drivers/rapidio/devices/tsi721.h
@@ -167,6 +167,8 @@
 #define TSI721_DEV_INTE		0x29840
 #define TSI721_DEV_INT		0x29844
 #define TSI721_DEV_INTSET	0x29848
+#define TSI721_DEV_INT_BDMA_CH	0x00002000
+#define TSI721_DEV_INT_BDMA_NCH	0x00001000
 #define TSI721_DEV_INT_SMSG_CH	0x00000800
 #define TSI721_DEV_INT_SMSG_NCH	0x00000400
 #define TSI721_DEV_INT_SR2PC_CH	0x00000200
@@ -181,6 +183,8 @@
 #define TSI721_INT_IMSG_CHAN(x)	(1 << (16 + (x)))
 #define TSI721_INT_OMSG_CHAN_M	0x0000ff00
 #define TSI721_INT_OMSG_CHAN(x)	(1 << (8 + (x)))
+#define TSI721_INT_BDMA_CHAN_M	0x000000ff
+#define TSI721_INT_BDMA_CHAN(x)	(1 << (x))
 
 /*
  * PC2SR block registers
@@ -235,14 +239,16 @@
  *   x = 0..7
  */
 
-#define TSI721_DMAC_DWRCNT(x)	(0x51000 + (x) * 0x1000)
-#define TSI721_DMAC_DRDCNT(x)	(0x51004 + (x) * 0x1000)
+#define TSI721_DMAC_BASE(x)	(0x51000 + (x) * 0x1000)
 
-#define TSI721_DMAC_CTL(x)	(0x51008 + (x) * 0x1000)
+#define TSI721_DMAC_DWRCNT	0x000
+#define TSI721_DMAC_DRDCNT	0x004
+
+#define TSI721_DMAC_CTL		0x008
 #define TSI721_DMAC_CTL_SUSP	0x00000002
 #define TSI721_DMAC_CTL_INIT	0x00000001
 
-#define TSI721_DMAC_INT(x)	(0x5100c + (x) * 0x1000)
+#define TSI721_DMAC_INT		0x00c
 #define TSI721_DMAC_INT_STFULL	0x00000010
 #define TSI721_DMAC_INT_DONE	0x00000008
 #define TSI721_DMAC_INT_SUSP	0x00000004
@@ -250,34 +256,33 @@
 #define TSI721_DMAC_INT_IOFDONE	0x00000001
 #define TSI721_DMAC_INT_ALL	0x0000001f
 
-#define TSI721_DMAC_INTSET(x)	(0x51010 + (x) * 0x1000)
+#define TSI721_DMAC_INTSET	0x010
 
-#define TSI721_DMAC_STS(x)	(0x51014 + (x) * 0x1000)
+#define TSI721_DMAC_STS		0x014
 #define TSI721_DMAC_STS_ABORT	0x00400000
 #define TSI721_DMAC_STS_RUN	0x00200000
 #define TSI721_DMAC_STS_CS	0x001f0000
 
-#define TSI721_DMAC_INTE(x)	(0x51018 + (x) * 0x1000)
+#define TSI721_DMAC_INTE	0x018
 
-#define TSI721_DMAC_DPTRL(x)	(0x51024 + (x) * 0x1000)
+#define TSI721_DMAC_DPTRL	0x024
 #define TSI721_DMAC_DPTRL_MASK	0xffffffe0
 
-#define TSI721_DMAC_DPTRH(x)	(0x51028 + (x) * 0x1000)
+#define TSI721_DMAC_DPTRH	0x028
 
-#define TSI721_DMAC_DSBL(x)	(0x5102c + (x) * 0x1000)
+#define TSI721_DMAC_DSBL	0x02c
 #define TSI721_DMAC_DSBL_MASK	0xffffffc0
 
-#define TSI721_DMAC_DSBH(x)	(0x51030 + (x) * 0x1000)
+#define TSI721_DMAC_DSBH	0x030
 
-#define TSI721_DMAC_DSSZ(x)	(0x51034 + (x) * 0x1000)
+#define TSI721_DMAC_DSSZ	0x034
 #define TSI721_DMAC_DSSZ_SIZE_M	0x0000000f
 #define TSI721_DMAC_DSSZ_SIZE(size)	(__fls(size) - 4)
 
-
-#define TSI721_DMAC_DSRP(x)	(0x51038 + (x) * 0x1000)
+#define TSI721_DMAC_DSRP	0x038
 #define TSI721_DMAC_DSRP_MASK	0x0007ffff
 
-#define TSI721_DMAC_DSWP(x)	(0x5103c + (x) * 0x1000)
+#define TSI721_DMAC_DSWP	0x03c
 #define TSI721_DMAC_DSWP_MASK	0x0007ffff
 
 #define TSI721_BDMA_INTE	0x5f000
@@ -612,6 +617,8 @@ enum dma_rtype {
 #define TSI721_DMACH_MAINT	0	/* DMA channel for maint requests */
 #define TSI721_DMACH_MAINT_NBD	32	/* Number of BDs for maint requests */
 
+#define TSI721_DMACH_DMA	1	/* DMA channel for data transfers */
+
 #define MSG_DMA_ENTRY_INX_TO_SIZE(x)	((0x10 << (x)) & 0xFFFF0)
 
 enum tsi721_smsg_int_flag {
@@ -626,7 +633,48 @@ enum tsi721_smsg_int_flag {
 
 /* Structures */
 
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+
+struct tsi721_tx_desc {
+	struct dma_async_tx_descriptor	txd;
+	struct tsi721_dma_desc		*hw_desc;
+	u16				destid;
+	/* low 64-bits of 66-bit RIO address */
+	u64				rio_addr;
+	/* upper 2-bits of 66-bit RIO address */
+	u8				rio_addr_u;
+	bool				interrupt;
+	struct list_head		desc_node;
+	struct list_head		tx_list;
+};
+
 struct tsi721_bdma_chan {
+	int		id;
+	void __iomem	*regs;
+	int		bd_num;		/* number of buffer descriptors */
+	void		*bd_base;	/* start of DMA descriptors */
+	dma_addr_t	bd_phys;
+	void		*sts_base;	/* start of DMA BD status FIFO */
+	dma_addr_t	sts_phys;
+	int		sts_size;
+	u32		sts_rdptr;
+	u32		wr_count;
+	u32		wr_count_next;
+
+	struct dma_chan		dchan;
+	struct tsi721_tx_desc	*tx_desc;
+	spinlock_t		lock;
+	struct list_head	active_list;
+	struct list_head	queue;
+	struct list_head	free_list;
+	dma_cookie_t		completed_cookie;
+	struct tasklet_struct	tasklet;
+};
+
+#endif /* CONFIG_RAPIDIO_DMA_ENGINE */
+
+struct tsi721_bdma_maint {
+	int		ch_id;		/* BDMA channel number */
 	int		bd_num;		/* number of buffer descriptors */
 	void		*bd_base;	/* start of DMA descriptors */
 	dma_addr_t	bd_phys;
@@ -721,6 +769,24 @@ enum tsi721_msix_vect {
 	TSI721_VECT_IMB1_INT,
 	TSI721_VECT_IMB2_INT,
 	TSI721_VECT_IMB3_INT,
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+	TSI721_VECT_DMA0_DONE,
+	TSI721_VECT_DMA1_DONE,
+	TSI721_VECT_DMA2_DONE,
+	TSI721_VECT_DMA3_DONE,
+	TSI721_VECT_DMA4_DONE,
+	TSI721_VECT_DMA5_DONE,
+	TSI721_VECT_DMA6_DONE,
+	TSI721_VECT_DMA7_DONE,
+	TSI721_VECT_DMA0_INT,
+	TSI721_VECT_DMA1_INT,
+	TSI721_VECT_DMA2_INT,
+	TSI721_VECT_DMA3_INT,
+	TSI721_VECT_DMA4_INT,
+	TSI721_VECT_DMA5_INT,
+	TSI721_VECT_DMA6_INT,
+	TSI721_VECT_DMA7_INT,
+#endif /* CONFIG_RAPIDIO_DMA_ENGINE */
 	TSI721_VECT_MAX
 };
 
@@ -754,7 +820,11 @@ struct tsi721_device {
 	u32		pw_discard_count;
 
 	/* BDMA Engine */
+	struct tsi721_bdma_maint mdma; /* Maintenance rd/wr request channel */
+
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
 	struct tsi721_bdma_chan bdma[TSI721_DMA_CHNUM];
+#endif
 
 	/* Inbound Messaging */
 	int		imsg_init[TSI721_IMSG_CHNUM];
@@ -765,4 +835,9 @@ struct tsi721_device {
 	struct tsi721_omsg_ring	omsg_ring[TSI721_OMSG_CHNUM];
 };
 
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+extern void tsi721_bdma_handler(struct tsi721_bdma_chan *bdma_chan);
+extern int __devinit tsi721_register_dma(struct tsi721_device *priv);
+#endif
+
 #endif
diff --git a/drivers/rapidio/devices/tsi721_dma.c b/drivers/rapidio/devices/tsi721_dma.c
new file mode 100644
index 000000000000..92e06a5c62ec
--- /dev/null
+++ b/drivers/rapidio/devices/tsi721_dma.c
@@ -0,0 +1,823 @@
+/*
+ * DMA Engine support for Tsi721 PCIExpress-to-SRIO bridge
+ *
+ * Copyright 2011 Integrated Device Technology, Inc.
+ * Alexandre Bounine <alexandre.bounine@idt.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/rio.h>
+#include <linux/rio_drv.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+#include <linux/delay.h>
+
+#include "tsi721.h"
+
+static inline struct tsi721_bdma_chan *to_tsi721_chan(struct dma_chan *chan)
+{
+	return container_of(chan, struct tsi721_bdma_chan, dchan);
+}
+
+static inline struct tsi721_device *to_tsi721(struct dma_device *ddev)
+{
+	return container_of(ddev, struct rio_mport, dma)->priv;
+}
+
+static inline
+struct tsi721_tx_desc *to_tsi721_desc(struct dma_async_tx_descriptor *txd)
+{
+	return container_of(txd, struct tsi721_tx_desc, txd);
+}
+
+static inline
+struct tsi721_tx_desc *tsi721_dma_first_active(
+				struct tsi721_bdma_chan *bdma_chan)
+{
+	return list_first_entry(&bdma_chan->active_list,
+				struct tsi721_tx_desc, desc_node);
+}
+
+static int tsi721_bdma_ch_init(struct tsi721_bdma_chan *bdma_chan)
+{
+	struct tsi721_dma_desc *bd_ptr;
+	struct device *dev = bdma_chan->dchan.device->dev;
+	u64		*sts_ptr;
+	dma_addr_t	bd_phys;
+	dma_addr_t	sts_phys;
+	int		sts_size;
+	int		bd_num = bdma_chan->bd_num;
+
+	dev_dbg(dev, "Init Block DMA Engine, CH%d\n", bdma_chan->id);
+
+	/* Allocate space for DMA descriptors */
+	bd_ptr = dma_zalloc_coherent(dev,
+				bd_num * sizeof(struct tsi721_dma_desc),
+				&bd_phys, GFP_KERNEL);
+	if (!bd_ptr)
+		return -ENOMEM;
+
+	bdma_chan->bd_phys = bd_phys;
+	bdma_chan->bd_base = bd_ptr;
+
+	dev_dbg(dev, "DMA descriptors @ %p (phys = %llx)\n",
+		bd_ptr, (unsigned long long)bd_phys);
+
+	/* Allocate space for descriptor status FIFO */
+	sts_size = (bd_num >= TSI721_DMA_MINSTSSZ) ?
+					bd_num : TSI721_DMA_MINSTSSZ;
+	sts_size = roundup_pow_of_two(sts_size);
+	sts_ptr = dma_zalloc_coherent(dev,
+				     sts_size * sizeof(struct tsi721_dma_sts),
+				     &sts_phys, GFP_KERNEL);
+	if (!sts_ptr) {
+		/* Free space allocated for DMA descriptors */
+		dma_free_coherent(dev,
+				  bd_num * sizeof(struct tsi721_dma_desc),
+				  bd_ptr, bd_phys);
+		bdma_chan->bd_base = NULL;
+		return -ENOMEM;
+	}
+
+	bdma_chan->sts_phys = sts_phys;
+	bdma_chan->sts_base = sts_ptr;
+	bdma_chan->sts_size = sts_size;
+
+	dev_dbg(dev,
+		"desc status FIFO @ %p (phys = %llx) size=0x%x\n",
+		sts_ptr, (unsigned long long)sts_phys, sts_size);
+
+	/* Initialize DMA descriptors ring */
+	bd_ptr[bd_num - 1].type_id = cpu_to_le32(DTYPE3 << 29);
+	bd_ptr[bd_num - 1].next_lo = cpu_to_le32((u64)bd_phys &
+						 TSI721_DMAC_DPTRL_MASK);
+	bd_ptr[bd_num - 1].next_hi = cpu_to_le32((u64)bd_phys >> 32);
+
+	/* Setup DMA descriptor pointers */
+	iowrite32(((u64)bd_phys >> 32),
+		bdma_chan->regs + TSI721_DMAC_DPTRH);
+	iowrite32(((u64)bd_phys & TSI721_DMAC_DPTRL_MASK),
+		bdma_chan->regs + TSI721_DMAC_DPTRL);
+
+	/* Setup descriptor status FIFO */
+	iowrite32(((u64)sts_phys >> 32),
+		bdma_chan->regs + TSI721_DMAC_DSBH);
+	iowrite32(((u64)sts_phys & TSI721_DMAC_DSBL_MASK),
+		bdma_chan->regs + TSI721_DMAC_DSBL);
+	iowrite32(TSI721_DMAC_DSSZ_SIZE(sts_size),
+		bdma_chan->regs + TSI721_DMAC_DSSZ);
+
+	/* Clear interrupt bits */
+	iowrite32(TSI721_DMAC_INT_ALL,
+		bdma_chan->regs + TSI721_DMAC_INT);
+
+	ioread32(bdma_chan->regs + TSI721_DMAC_INT);
+
+	/* Toggle DMA channel initialization */
+	iowrite32(TSI721_DMAC_CTL_INIT,	bdma_chan->regs + TSI721_DMAC_CTL);
+	ioread32(bdma_chan->regs + TSI721_DMAC_CTL);
+	bdma_chan->wr_count = bdma_chan->wr_count_next = 0;
+	bdma_chan->sts_rdptr = 0;
+	udelay(10);
+
+	return 0;
+}
+
+static int tsi721_bdma_ch_free(struct tsi721_bdma_chan *bdma_chan)
+{
+	u32 ch_stat;
+
+	if (bdma_chan->bd_base == NULL)
+		return 0;
+
+	/* Check if DMA channel still running */
+	ch_stat = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
+	if (ch_stat & TSI721_DMAC_STS_RUN)
+		return -EFAULT;
+
+	/* Put DMA channel into init state */
+	iowrite32(TSI721_DMAC_CTL_INIT,	bdma_chan->regs + TSI721_DMAC_CTL);
+
+	/* Free space allocated for DMA descriptors */
+	dma_free_coherent(bdma_chan->dchan.device->dev,
+		bdma_chan->bd_num * sizeof(struct tsi721_dma_desc),
+		bdma_chan->bd_base, bdma_chan->bd_phys);
+	bdma_chan->bd_base = NULL;
+
+	/* Free space allocated for status FIFO */
+	dma_free_coherent(bdma_chan->dchan.device->dev,
+		bdma_chan->sts_size * sizeof(struct tsi721_dma_sts),
+		bdma_chan->sts_base, bdma_chan->sts_phys);
+	bdma_chan->sts_base = NULL;
+	return 0;
+}
+
+static void
+tsi721_bdma_interrupt_enable(struct tsi721_bdma_chan *bdma_chan, int enable)
+{
+	if (enable) {
+		/* Clear pending BDMA channel interrupts */
+		iowrite32(TSI721_DMAC_INT_ALL,
+			bdma_chan->regs + TSI721_DMAC_INT);
+		ioread32(bdma_chan->regs + TSI721_DMAC_INT);
+		/* Enable BDMA channel interrupts */
+		iowrite32(TSI721_DMAC_INT_ALL,
+			bdma_chan->regs + TSI721_DMAC_INTE);
+	} else {
+		/* Disable BDMA channel interrupts */
+		iowrite32(0, bdma_chan->regs + TSI721_DMAC_INTE);
+		/* Clear pending BDMA channel interrupts */
+		iowrite32(TSI721_DMAC_INT_ALL,
+			bdma_chan->regs + TSI721_DMAC_INT);
+	}
+
+}
+
+static bool tsi721_dma_is_idle(struct tsi721_bdma_chan *bdma_chan)
+{
+	u32 sts;
+
+	sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
+	return ((sts & TSI721_DMAC_STS_RUN) == 0);
+}
+
+void tsi721_bdma_handler(struct tsi721_bdma_chan *bdma_chan)
+{
+	/* Disable BDMA channel interrupts */
+	iowrite32(0, bdma_chan->regs + TSI721_DMAC_INTE);
+
+	tasklet_schedule(&bdma_chan->tasklet);
+}
+
+#ifdef CONFIG_PCI_MSI
+/**
+ * tsi721_omsg_msix - MSI-X interrupt handler for BDMA channels
+ * @irq: Linux interrupt number
+ * @ptr: Pointer to interrupt-specific data (BDMA channel structure)
+ *
+ * Handles BDMA channel interrupts signaled using MSI-X.
+ */
+static irqreturn_t tsi721_bdma_msix(int irq, void *ptr)
+{
+	struct tsi721_bdma_chan *bdma_chan = ptr;
+
+	tsi721_bdma_handler(bdma_chan);
+	return IRQ_HANDLED;
+}
+#endif /* CONFIG_PCI_MSI */
+
+/* Must be called with the spinlock held */
+static void tsi721_start_dma(struct tsi721_bdma_chan *bdma_chan)
+{
+	if (!tsi721_dma_is_idle(bdma_chan)) {
+		dev_err(bdma_chan->dchan.device->dev,
+			"BUG: Attempt to start non-idle channel\n");
+		return;
+	}
+
+	if (bdma_chan->wr_count == bdma_chan->wr_count_next) {
+		dev_err(bdma_chan->dchan.device->dev,
+			"BUG: Attempt to start DMA with no BDs ready\n");
+		return;
+	}
+
+	dev_dbg(bdma_chan->dchan.device->dev,
+		"tx_chan: %p, chan: %d, regs: %p\n",
+		bdma_chan, bdma_chan->dchan.chan_id, bdma_chan->regs);
+
+	iowrite32(bdma_chan->wr_count_next,
+		bdma_chan->regs + TSI721_DMAC_DWRCNT);
+	ioread32(bdma_chan->regs + TSI721_DMAC_DWRCNT);
+
+	bdma_chan->wr_count = bdma_chan->wr_count_next;
+}
+
+static void tsi721_desc_put(struct tsi721_bdma_chan *bdma_chan,
+			    struct tsi721_tx_desc *desc)
+{
+	dev_dbg(bdma_chan->dchan.device->dev,
+		"Put desc: %p into free list\n", desc);
+
+	if (desc) {
+		spin_lock_bh(&bdma_chan->lock);
+		list_splice_init(&desc->tx_list, &bdma_chan->free_list);
+		list_add(&desc->desc_node, &bdma_chan->free_list);
+		bdma_chan->wr_count_next = bdma_chan->wr_count;
+		spin_unlock_bh(&bdma_chan->lock);
+	}
+}
+
+static
+struct tsi721_tx_desc *tsi721_desc_get(struct tsi721_bdma_chan *bdma_chan)
+{
+	struct tsi721_tx_desc *tx_desc, *_tx_desc;
+	struct tsi721_tx_desc *ret = NULL;
+	int i;
+
+	spin_lock_bh(&bdma_chan->lock);
+	list_for_each_entry_safe(tx_desc, _tx_desc,
+				 &bdma_chan->free_list, desc_node) {
+		if (async_tx_test_ack(&tx_desc->txd)) {
+			list_del(&tx_desc->desc_node);
+			ret = tx_desc;
+			break;
+		}
+		dev_dbg(bdma_chan->dchan.device->dev,
+			"desc %p not ACKed\n", tx_desc);
+	}
+
+	i = bdma_chan->wr_count_next % bdma_chan->bd_num;
+	if (i == bdma_chan->bd_num - 1) {
+		i = 0;
+		bdma_chan->wr_count_next++; /* skip link descriptor */
+	}
+
+	bdma_chan->wr_count_next++;
+	tx_desc->txd.phys = bdma_chan->bd_phys +
+				i * sizeof(struct tsi721_dma_desc);
+	tx_desc->hw_desc = &((struct tsi721_dma_desc *)bdma_chan->bd_base)[i];
+
+	spin_unlock_bh(&bdma_chan->lock);
+
+	return ret;
+}
+
+static int
+tsi721_fill_desc(struct tsi721_bdma_chan *bdma_chan,
+	struct tsi721_tx_desc *desc, struct scatterlist *sg,
+	enum dma_rtype rtype, u32 sys_size)
+{
+	struct tsi721_dma_desc *bd_ptr = desc->hw_desc;
+	u64 rio_addr;
+
+	if (sg_dma_len(sg) > TSI721_DMAD_BCOUNT1 + 1) {
+		dev_err(bdma_chan->dchan.device->dev,
+			"SG element is too large\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(bdma_chan->dchan.device->dev,
+		"desc: 0x%llx, addr: 0x%llx len: 0x%x\n",
+		(u64)desc->txd.phys, (unsigned long long)sg_dma_address(sg),
+		sg_dma_len(sg));
+
+	dev_dbg(bdma_chan->dchan.device->dev,
+		"bd_ptr = %p did=%d raddr=0x%llx\n",
+		bd_ptr, desc->destid, desc->rio_addr);
+
+	/* Initialize DMA descriptor */
+	bd_ptr->type_id = cpu_to_le32((DTYPE1 << 29) |
+					(rtype << 19) | desc->destid);
+	if (desc->interrupt)
+		bd_ptr->type_id |= cpu_to_le32(TSI721_DMAD_IOF);
+	bd_ptr->bcount = cpu_to_le32(((desc->rio_addr & 0x3) << 30) |
+					(sys_size << 26) | sg_dma_len(sg));
+	rio_addr = (desc->rio_addr >> 2) |
+				((u64)(desc->rio_addr_u & 0x3) << 62);
+	bd_ptr->raddr_lo = cpu_to_le32(rio_addr & 0xffffffff);
+	bd_ptr->raddr_hi = cpu_to_le32(rio_addr >> 32);
+	bd_ptr->t1.bufptr_lo = cpu_to_le32(
+					(u64)sg_dma_address(sg) & 0xffffffff);
+	bd_ptr->t1.bufptr_hi = cpu_to_le32((u64)sg_dma_address(sg) >> 32);
+	bd_ptr->t1.s_dist = 0;
+	bd_ptr->t1.s_size = 0;
+
+	return 0;
+}
+
+static void tsi721_dma_chain_complete(struct tsi721_bdma_chan *bdma_chan,
+				      struct tsi721_tx_desc *desc)
+{
+	struct dma_async_tx_descriptor *txd = &desc->txd;
+	dma_async_tx_callback callback = txd->callback;
+	void *param = txd->callback_param;
+
+	list_splice_init(&desc->tx_list, &bdma_chan->free_list);
+	list_move(&desc->desc_node, &bdma_chan->free_list);
+	bdma_chan->completed_cookie = txd->cookie;
+
+	if (callback)
+		callback(param);
+}
+
+static void tsi721_dma_complete_all(struct tsi721_bdma_chan *bdma_chan)
+{
+	struct tsi721_tx_desc *desc, *_d;
+	LIST_HEAD(list);
+
+	BUG_ON(!tsi721_dma_is_idle(bdma_chan));
+
+	if (!list_empty(&bdma_chan->queue))
+		tsi721_start_dma(bdma_chan);
+
+	list_splice_init(&bdma_chan->active_list, &list);
+	list_splice_init(&bdma_chan->queue, &bdma_chan->active_list);
+
+	list_for_each_entry_safe(desc, _d, &list, desc_node)
+		tsi721_dma_chain_complete(bdma_chan, desc);
+}
+
+static void tsi721_clr_stat(struct tsi721_bdma_chan *bdma_chan)
+{
+	u32 srd_ptr;
+	u64 *sts_ptr;
+	int i, j;
+
+	/* Check and clear descriptor status FIFO entries */
+	srd_ptr = bdma_chan->sts_rdptr;
+	sts_ptr = bdma_chan->sts_base;
+	j = srd_ptr * 8;
+	while (sts_ptr[j]) {
+		for (i = 0; i < 8 && sts_ptr[j]; i++, j++)
+			sts_ptr[j] = 0;
+
+		++srd_ptr;
+		srd_ptr %= bdma_chan->sts_size;
+		j = srd_ptr * 8;
+	}
+
+	iowrite32(srd_ptr, bdma_chan->regs + TSI721_DMAC_DSRP);
+	bdma_chan->sts_rdptr = srd_ptr;
+}
+
+static void tsi721_advance_work(struct tsi721_bdma_chan *bdma_chan)
+{
+	if (list_empty(&bdma_chan->active_list) ||
+		list_is_singular(&bdma_chan->active_list)) {
+		dev_dbg(bdma_chan->dchan.device->dev,
+			"%s: Active_list empty\n", __func__);
+		tsi721_dma_complete_all(bdma_chan);
+	} else {
+		dev_dbg(bdma_chan->dchan.device->dev,
+			"%s: Active_list NOT empty\n", __func__);
+		tsi721_dma_chain_complete(bdma_chan,
+					tsi721_dma_first_active(bdma_chan));
+		tsi721_start_dma(bdma_chan);
+	}
+}
+
+static void tsi721_dma_tasklet(unsigned long data)
+{
+	struct tsi721_bdma_chan *bdma_chan = (struct tsi721_bdma_chan *)data;
+	u32 dmac_int, dmac_sts;
+
+	dmac_int = ioread32(bdma_chan->regs + TSI721_DMAC_INT);
+	dev_dbg(bdma_chan->dchan.device->dev, "%s: DMAC%d_INT = 0x%x\n",
+		__func__, bdma_chan->id, dmac_int);
+	/* Clear channel interrupts */
+	iowrite32(dmac_int, bdma_chan->regs + TSI721_DMAC_INT);
+
+	if (dmac_int & TSI721_DMAC_INT_ERR) {
+		dmac_sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
+		dev_err(bdma_chan->dchan.device->dev,
+			"%s: DMA ERROR - DMAC%d_STS = 0x%x\n",
+			__func__, bdma_chan->id, dmac_sts);
+	}
+
+	if (dmac_int & TSI721_DMAC_INT_STFULL) {
+		dev_err(bdma_chan->dchan.device->dev,
+			"%s: DMAC%d descriptor status FIFO is full\n",
+			__func__, bdma_chan->id);
+	}
+
+	if (dmac_int & (TSI721_DMAC_INT_DONE | TSI721_DMAC_INT_IOFDONE)) {
+		tsi721_clr_stat(bdma_chan);
+		spin_lock(&bdma_chan->lock);
+		tsi721_advance_work(bdma_chan);
+		spin_unlock(&bdma_chan->lock);
+	}
+
+	/* Re-Enable BDMA channel interrupts */
+	iowrite32(TSI721_DMAC_INT_ALL, bdma_chan->regs + TSI721_DMAC_INTE);
+}
+
+static dma_cookie_t tsi721_tx_submit(struct dma_async_tx_descriptor *txd)
+{
+	struct tsi721_tx_desc *desc = to_tsi721_desc(txd);
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(txd->chan);
+	dma_cookie_t cookie;
+
+	spin_lock_bh(&bdma_chan->lock);
+
+	cookie = txd->chan->cookie;
+	if (++cookie < 0)
+		cookie = 1;
+	txd->chan->cookie = cookie;
+	txd->cookie = cookie;
+
+	if (list_empty(&bdma_chan->active_list)) {
+		list_add_tail(&desc->desc_node, &bdma_chan->active_list);
+		tsi721_start_dma(bdma_chan);
+	} else {
+		list_add_tail(&desc->desc_node, &bdma_chan->queue);
+	}
+
+	spin_unlock_bh(&bdma_chan->lock);
+	return cookie;
+}
+
+static int tsi721_alloc_chan_resources(struct dma_chan *dchan)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+#ifdef CONFIG_PCI_MSI
+	struct tsi721_device *priv = to_tsi721(dchan->device);
+#endif
+	struct tsi721_tx_desc *desc = NULL;
+	LIST_HEAD(tmp_list);
+	int i;
+	int rc;
+
+	if (bdma_chan->bd_base)
+		return bdma_chan->bd_num - 1;
+
+	/* Initialize BDMA channel */
+	if (tsi721_bdma_ch_init(bdma_chan)) {
+		dev_err(dchan->device->dev, "Unable to initialize data DMA"
+			" channel %d, aborting\n", bdma_chan->id);
+		return -ENOMEM;
+	}
+
+	/* Alocate matching number of logical descriptors */
+	desc = kcalloc((bdma_chan->bd_num - 1), sizeof(struct tsi721_tx_desc),
+			GFP_KERNEL);
+	if (!desc) {
+		dev_err(dchan->device->dev,
+			"Failed to allocate logical descriptors\n");
+		rc = -ENOMEM;
+		goto err_out;
+	}
+
+	bdma_chan->tx_desc = desc;
+
+	for (i = 0; i < bdma_chan->bd_num - 1; i++) {
+		dma_async_tx_descriptor_init(&desc[i].txd, dchan);
+		desc[i].txd.tx_submit = tsi721_tx_submit;
+		desc[i].txd.flags = DMA_CTRL_ACK;
+		INIT_LIST_HEAD(&desc[i].tx_list);
+		list_add_tail(&desc[i].desc_node, &tmp_list);
+	}
+
+	spin_lock_bh(&bdma_chan->lock);
+	list_splice(&tmp_list, &bdma_chan->free_list);
+	bdma_chan->completed_cookie = dchan->cookie = 1;
+	spin_unlock_bh(&bdma_chan->lock);
+
+#ifdef CONFIG_PCI_MSI
+	if (priv->flags & TSI721_USING_MSIX) {
+		/* Request interrupt service if we are in MSI-X mode */
+		rc = request_irq(
+			priv->msix[TSI721_VECT_DMA0_DONE +
+				   bdma_chan->id].vector,
+			tsi721_bdma_msix, 0,
+			priv->msix[TSI721_VECT_DMA0_DONE +
+				   bdma_chan->id].irq_name,
+			(void *)bdma_chan);
+
+		if (rc) {
+			dev_dbg(dchan->device->dev,
+				"Unable to allocate MSI-X interrupt for "
+				"BDMA%d-DONE\n", bdma_chan->id);
+			goto err_out;
+		}
+
+		rc = request_irq(priv->msix[TSI721_VECT_DMA0_INT +
+					    bdma_chan->id].vector,
+				tsi721_bdma_msix, 0,
+				priv->msix[TSI721_VECT_DMA0_INT +
+					   bdma_chan->id].irq_name,
+				(void *)bdma_chan);
+
+		if (rc)	{
+			dev_dbg(dchan->device->dev,
+				"Unable to allocate MSI-X interrupt for "
+				"BDMA%d-INT\n", bdma_chan->id);
+			free_irq(
+				priv->msix[TSI721_VECT_DMA0_DONE +
+					   bdma_chan->id].vector,
+				(void *)bdma_chan);
+			rc = -EIO;
+			goto err_out;
+		}
+	}
+#endif /* CONFIG_PCI_MSI */
+
+	tasklet_enable(&bdma_chan->tasklet);
+	tsi721_bdma_interrupt_enable(bdma_chan, 1);
+
+	return bdma_chan->bd_num - 1;
+
+err_out:
+	kfree(desc);
+	tsi721_bdma_ch_free(bdma_chan);
+	return rc;
+}
+
+static void tsi721_free_chan_resources(struct dma_chan *dchan)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+#ifdef CONFIG_PCI_MSI
+	struct tsi721_device *priv = to_tsi721(dchan->device);
+#endif
+	LIST_HEAD(list);
+
+	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
+
+	if (bdma_chan->bd_base == NULL)
+		return;
+
+	BUG_ON(!list_empty(&bdma_chan->active_list));
+	BUG_ON(!list_empty(&bdma_chan->queue));
+
+	tasklet_disable(&bdma_chan->tasklet);
+
+	spin_lock_bh(&bdma_chan->lock);
+	list_splice_init(&bdma_chan->free_list, &list);
+	spin_unlock_bh(&bdma_chan->lock);
+
+	tsi721_bdma_interrupt_enable(bdma_chan, 0);
+
+#ifdef CONFIG_PCI_MSI
+	if (priv->flags & TSI721_USING_MSIX) {
+		free_irq(priv->msix[TSI721_VECT_DMA0_DONE +
+				    bdma_chan->id].vector, (void *)bdma_chan);
+		free_irq(priv->msix[TSI721_VECT_DMA0_INT +
+				    bdma_chan->id].vector, (void *)bdma_chan);
+	}
+#endif /* CONFIG_PCI_MSI */
+
+	tsi721_bdma_ch_free(bdma_chan);
+	kfree(bdma_chan->tx_desc);
+}
+
+static
+enum dma_status tsi721_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
+				 struct dma_tx_state *txstate)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+	dma_cookie_t		last_used;
+	dma_cookie_t		last_completed;
+	int			ret;
+
+	spin_lock_bh(&bdma_chan->lock);
+	last_completed = bdma_chan->completed_cookie;
+	last_used = dchan->cookie;
+	spin_unlock_bh(&bdma_chan->lock);
+
+	ret = dma_async_is_complete(cookie, last_completed, last_used);
+
+	dma_set_tx_state(txstate, last_completed, last_used, 0);
+
+	dev_dbg(dchan->device->dev,
+		"%s: exit, ret: %d, last_completed: %d, last_used: %d\n",
+		__func__, ret, last_completed, last_used);
+
+	return ret;
+}
+
+static void tsi721_issue_pending(struct dma_chan *dchan)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+
+	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
+
+	if (tsi721_dma_is_idle(bdma_chan)) {
+		spin_lock_bh(&bdma_chan->lock);
+		tsi721_advance_work(bdma_chan);
+		spin_unlock_bh(&bdma_chan->lock);
+	} else
+		dev_dbg(dchan->device->dev,
+			"%s: DMA channel still busy\n", __func__);
+}
+
+static
+struct dma_async_tx_descriptor *tsi721_prep_rio_sg(struct dma_chan *dchan,
+			struct scatterlist *sgl, unsigned int sg_len,
+			enum dma_transfer_direction dir, unsigned long flags,
+			void *tinfo)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+	struct tsi721_tx_desc *desc = NULL;
+	struct tsi721_tx_desc *first = NULL;
+	struct scatterlist *sg;
+	struct rio_dma_ext *rext = tinfo;
+	u64 rio_addr = rext->rio_addr; /* limited to 64-bit rio_addr for now */
+	unsigned int i;
+	u32 sys_size = dma_to_mport(dchan->device)->sys_size;
+	enum dma_rtype rtype;
+
+	if (!sgl || !sg_len) {
+		dev_err(dchan->device->dev, "%s: No SG list\n", __func__);
+		return NULL;
+	}
+
+	if (dir == DMA_DEV_TO_MEM)
+		rtype = NREAD;
+	else if (dir == DMA_MEM_TO_DEV) {
+		switch (rext->wr_type) {
+		case RDW_ALL_NWRITE:
+			rtype = ALL_NWRITE;
+			break;
+		case RDW_ALL_NWRITE_R:
+			rtype = ALL_NWRITE_R;
+			break;
+		case RDW_LAST_NWRITE_R:
+		default:
+			rtype = LAST_NWRITE_R;
+			break;
+		}
+	} else {
+		dev_err(dchan->device->dev,
+			"%s: Unsupported DMA direction option\n", __func__);
+		return NULL;
+	}
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		int err;
+
+		dev_dbg(dchan->device->dev, "%s: sg #%d\n", __func__, i);
+		desc = tsi721_desc_get(bdma_chan);
+		if (!desc) {
+			dev_err(dchan->device->dev,
+				"Not enough descriptors available\n");
+			goto err_desc_get;
+		}
+
+		if (sg_is_last(sg))
+			desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
+		else
+			desc->interrupt = false;
+
+		desc->destid = rext->destid;
+		desc->rio_addr = rio_addr;
+		desc->rio_addr_u = 0;
+
+		err = tsi721_fill_desc(bdma_chan, desc, sg, rtype, sys_size);
+		if (err) {
+			dev_err(dchan->device->dev,
+				"Failed to build desc: %d\n", err);
+			goto err_desc_get;
+		}
+
+		rio_addr += sg_dma_len(sg);
+
+		if (!first)
+			first = desc;
+		else
+			list_add_tail(&desc->desc_node, &first->tx_list);
+	}
+
+	first->txd.cookie = -EBUSY;
+	desc->txd.flags = flags;
+
+	return &first->txd;
+
+err_desc_get:
+	tsi721_desc_put(bdma_chan, first);
+	return NULL;
+}
+
+static int tsi721_device_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd,
+			     unsigned long arg)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+	struct tsi721_tx_desc *desc, *_d;
+	LIST_HEAD(list);
+
+	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
+
+	if (cmd != DMA_TERMINATE_ALL)
+		return -ENXIO;
+
+	spin_lock_bh(&bdma_chan->lock);
+
+	/* make sure to stop the transfer */
+	iowrite32(TSI721_DMAC_CTL_SUSP, bdma_chan->regs + TSI721_DMAC_CTL);
+
+	list_splice_init(&bdma_chan->active_list, &list);
+	list_splice_init(&bdma_chan->queue, &list);
+
+	list_for_each_entry_safe(desc, _d, &list, desc_node)
+		tsi721_dma_chain_complete(bdma_chan, desc);
+
+	spin_unlock_bh(&bdma_chan->lock);
+
+	return 0;
+}
+
+int __devinit tsi721_register_dma(struct tsi721_device *priv)
+{
+	int i;
+	int nr_channels = TSI721_DMA_MAXCH;
+	int err;
+	struct rio_mport *mport = priv->mport;
+
+	mport->dma.dev = &priv->pdev->dev;
+	mport->dma.chancnt = nr_channels;
+
+	INIT_LIST_HEAD(&mport->dma.channels);
+
+	for (i = 0; i < nr_channels; i++) {
+		struct tsi721_bdma_chan *bdma_chan = &priv->bdma[i];
+
+		if (i == TSI721_DMACH_MAINT)
+			continue;
+
+		bdma_chan->bd_num = 64;
+		bdma_chan->regs = priv->regs + TSI721_DMAC_BASE(i);
+
+		bdma_chan->dchan.device = &mport->dma;
+		bdma_chan->dchan.cookie = 1;
+		bdma_chan->dchan.chan_id = i;
+		bdma_chan->id = i;
+
+		spin_lock_init(&bdma_chan->lock);
+
+		INIT_LIST_HEAD(&bdma_chan->active_list);
+		INIT_LIST_HEAD(&bdma_chan->queue);
+		INIT_LIST_HEAD(&bdma_chan->free_list);
+
+		tasklet_init(&bdma_chan->tasklet, tsi721_dma_tasklet,
+			     (unsigned long)bdma_chan);
+		tasklet_disable(&bdma_chan->tasklet);
+		list_add_tail(&bdma_chan->dchan.device_node,
+			      &mport->dma.channels);
+	}
+
+	dma_cap_zero(mport->dma.cap_mask);
+	dma_cap_set(DMA_PRIVATE, mport->dma.cap_mask);
+	dma_cap_set(DMA_SLAVE, mport->dma.cap_mask);
+
+	mport->dma.device_alloc_chan_resources = tsi721_alloc_chan_resources;
+	mport->dma.device_free_chan_resources = tsi721_free_chan_resources;
+	mport->dma.device_tx_status = tsi721_tx_status;
+	mport->dma.device_issue_pending = tsi721_issue_pending;
+	mport->dma.device_prep_slave_sg = tsi721_prep_rio_sg;
+	mport->dma.device_control = tsi721_device_control;
+
+	err = dma_async_device_register(&mport->dma);
+	if (err)
+		dev_err(&priv->pdev->dev, "Failed to register DMA device\n");
+
+	return err;
+}
diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index 86c9a091a2ff..c40665a4fa33 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -1121,6 +1121,87 @@ int rio_std_route_clr_table(struct rio_mport *mport, u16 destid, u8 hopcount,
 	return 0;
 }
 
+#ifdef CONFIG_RAPIDIO_DMA_ENGINE
+
+static bool rio_chan_filter(struct dma_chan *chan, void *arg)
+{
+	struct rio_dev *rdev = arg;
+
+	/* Check that DMA device belongs to the right MPORT */
+	return (rdev->net->hport ==
+		container_of(chan->device, struct rio_mport, dma));
+}
+
+/**
+ * rio_request_dma - request RapidIO capable DMA channel that supports
+ *   specified target RapidIO device.
+ * @rdev: RIO device control structure
+ *
+ * Returns pointer to allocated DMA channel or NULL if failed.
+ */
+struct dma_chan *rio_request_dma(struct rio_dev *rdev)
+{
+	dma_cap_mask_t mask;
+	struct dma_chan *dchan;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	dchan = dma_request_channel(mask, rio_chan_filter, rdev);
+
+	return dchan;
+}
+EXPORT_SYMBOL_GPL(rio_request_dma);
+
+/**
+ * rio_release_dma - release specified DMA channel
+ * @dchan: DMA channel to release
+ */
+void rio_release_dma(struct dma_chan *dchan)
+{
+	dma_release_channel(dchan);
+}
+EXPORT_SYMBOL_GPL(rio_release_dma);
+
+/**
+ * rio_dma_prep_slave_sg - RapidIO specific wrapper
+ *   for device_prep_slave_sg callback defined by DMAENGINE.
+ * @rdev: RIO device control structure
+ * @dchan: DMA channel to configure
+ * @data: RIO specific data descriptor
+ * @direction: DMA data transfer direction (TO or FROM the device)
+ * @flags: dmaengine defined flags
+ *
+ * Initializes RapidIO capable DMA channel for the specified data transfer.
+ * Uses DMA channel private extension to pass information related to remote
+ * target RIO device.
+ * Returns pointer to DMA transaction descriptor or NULL if failed.
+ */
+struct dma_async_tx_descriptor *rio_dma_prep_slave_sg(struct rio_dev *rdev,
+	struct dma_chan *dchan, struct rio_dma_data *data,
+	enum dma_transfer_direction direction, unsigned long flags)
+{
+	struct dma_async_tx_descriptor *txd = NULL;
+	struct rio_dma_ext rio_ext;
+
+	if (dchan->device->device_prep_slave_sg == NULL) {
+		pr_err("%s: prep_rio_sg == NULL\n", __func__);
+		return NULL;
+	}
+
+	rio_ext.destid = rdev->destid;
+	rio_ext.rio_addr_u = data->rio_addr_u;
+	rio_ext.rio_addr = data->rio_addr;
+	rio_ext.wr_type = data->wr_type;
+
+	txd = dmaengine_prep_rio_sg(dchan, data->sg, data->sg_len,
+					direction, flags, &rio_ext);
+
+	return txd;
+}
+EXPORT_SYMBOL_GPL(rio_dma_prep_slave_sg);
+
+#endif /* CONFIG_RAPIDIO_DMA_ENGINE */
+
 static void rio_fixup_device(struct rio_dev *dev)
 {
 }