Merge branch 'topic/bcm' into for-linus

3 files changed, 1801 insertions, 0 deletions

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 24e8597b2c3e..686ae67d7e2a 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -99,6 +99,21 @@ config AXI_DMAC
 	  controller is often used in Analog Device's reference designs for FPGA
 	  platforms.
 
+config BCM_SBA_RAID
+	tristate "Broadcom SBA RAID engine support"
+	depends on ARM64 || COMPILE_TEST
+	depends on MAILBOX && RAID6_PQ
+	select DMA_ENGINE
+	select DMA_ENGINE_RAID
+	select ASYNC_TX_DISABLE_XOR_VAL_DMA
+	select ASYNC_TX_DISABLE_PQ_VAL_DMA
+	default ARCH_BCM_IPROC
+	help
+	  Enable support for Broadcom SBA RAID Engine. The SBA RAID
+	  engine is available on most of the Broadcom iProc SoCs. It
+	  has the capability to offload memcpy, xor and pq computation
+	  for raid5/6.
+
 config COH901318
 	bool "ST-Ericsson COH901318 DMA support"
 	select DMA_ENGINE
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 0b723e94d9e6..d12ab2985ed1 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_AMCC_PPC440SPE_ADMA) += ppc4xx/
 obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
 obj-$(CONFIG_AT_XDMAC) += at_xdmac.o
 obj-$(CONFIG_AXI_DMAC) += dma-axi-dmac.o
+obj-$(CONFIG_BCM_SBA_RAID) += bcm-sba-raid.o
 obj-$(CONFIG_COH901318) += coh901318.o coh901318_lli.o
 obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o
 obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
diff --git a/drivers/dma/bcm-sba-raid.c b/drivers/dma/bcm-sba-raid.c
new file mode 100644
index 000000000000..e41bbc7cb094
--- /dev/null
+++ b/drivers/dma/bcm-sba-raid.c
@@ -0,0 +1,1785 @@
+/*
+ * Copyright (C) 2017 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * Broadcom SBA RAID Driver
+ *
+ * The Broadcom stream buffer accelerator (SBA) provides offloading
+ * capabilities for RAID operations. The SBA offload engine is accessible
+ * via Broadcom SoC specific ring manager. Two or more offload engines
+ * can share same Broadcom SoC specific ring manager due to this Broadcom
+ * SoC specific ring manager driver is implemented as a mailbox controller
+ * driver and offload engine drivers are implemented as mallbox clients.
+ *
+ * Typically, Broadcom SoC specific ring manager will implement larger
+ * number of hardware rings over one or more SBA hardware devices. By
+ * design, the internal buffer size of SBA hardware device is limited
+ * but all offload operations supported by SBA can be broken down into
+ * multiple small size requests and executed parallely on multiple SBA
+ * hardware devices for achieving high through-put.
+ *
+ * The Broadcom SBA RAID driver does not require any register programming
+ * except submitting request to SBA hardware device via mailbox channels.
+ * This driver implements a DMA device with one DMA channel using a set
+ * of mailbox channels provided by Broadcom SoC specific ring manager
+ * driver. To exploit parallelism (as described above), all DMA request
+ * coming to SBA RAID DMA channel are broken down to smaller requests
+ * and submitted to multiple mailbox channels in round-robin fashion.
+ * For having more SBA DMA channels, we can create more SBA device nodes
+ * in Broadcom SoC specific DTS based on number of hardware rings supported
+ * by Broadcom SoC ring manager.
+ */
+
+#include <linux/bitops.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/list.h>
+#include <linux/mailbox_client.h>
+#include <linux/mailbox/brcm-message.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/raid/pq.h>
+
+#include "dmaengine.h"
+
+/* SBA command related defines */
+#define SBA_TYPE_SHIFT					48
+#define SBA_TYPE_MASK					GENMASK(1, 0)
+#define SBA_TYPE_A					0x0
+#define SBA_TYPE_B					0x2
+#define SBA_TYPE_C					0x3
+#define SBA_USER_DEF_SHIFT				32
+#define SBA_USER_DEF_MASK				GENMASK(15, 0)
+#define SBA_R_MDATA_SHIFT				24
+#define SBA_R_MDATA_MASK				GENMASK(7, 0)
+#define SBA_C_MDATA_MS_SHIFT				18
+#define SBA_C_MDATA_MS_MASK				GENMASK(1, 0)
+#define SBA_INT_SHIFT					17
+#define SBA_INT_MASK					BIT(0)
+#define SBA_RESP_SHIFT					16
+#define SBA_RESP_MASK					BIT(0)
+#define SBA_C_MDATA_SHIFT				8
+#define SBA_C_MDATA_MASK				GENMASK(7, 0)
+#define SBA_C_MDATA_BNUMx_SHIFT(__bnum)			(2 * (__bnum))
+#define SBA_C_MDATA_BNUMx_MASK				GENMASK(1, 0)
+#define SBA_C_MDATA_DNUM_SHIFT				5
+#define SBA_C_MDATA_DNUM_MASK				GENMASK(4, 0)
+#define SBA_C_MDATA_LS(__v)				((__v) & 0xff)
+#define SBA_C_MDATA_MS(__v)				(((__v) >> 8) & 0x3)
+#define SBA_CMD_SHIFT					0
+#define SBA_CMD_MASK					GENMASK(3, 0)
+#define SBA_CMD_ZERO_BUFFER				0x4
+#define SBA_CMD_ZERO_ALL_BUFFERS			0x8
+#define SBA_CMD_LOAD_BUFFER				0x9
+#define SBA_CMD_XOR					0xa
+#define SBA_CMD_GALOIS_XOR				0xb
+#define SBA_CMD_WRITE_BUFFER				0xc
+#define SBA_CMD_GALOIS					0xe
+
+/* Driver helper macros */
+#define to_sba_request(tx)		\
+	container_of(tx, struct sba_request, tx)
+#define to_sba_device(dchan)		\
+	container_of(dchan, struct sba_device, dma_chan)
+
+enum sba_request_state {
+	SBA_REQUEST_STATE_FREE = 1,
+	SBA_REQUEST_STATE_ALLOCED = 2,
+	SBA_REQUEST_STATE_PENDING = 3,
+	SBA_REQUEST_STATE_ACTIVE = 4,
+	SBA_REQUEST_STATE_RECEIVED = 5,
+	SBA_REQUEST_STATE_COMPLETED = 6,
+	SBA_REQUEST_STATE_ABORTED = 7,
+};
+
+struct sba_request {
+	/* Global state */
+	struct list_head node;
+	struct sba_device *sba;
+	enum sba_request_state state;
+	bool fence;
+	/* Chained requests management */
+	struct sba_request *first;
+	struct list_head next;
+	unsigned int next_count;
+	atomic_t next_pending_count;
+	/* BRCM message data */
+	void *resp;
+	dma_addr_t resp_dma;
+	struct brcm_sba_command *cmds;
+	struct brcm_message msg;
+	struct dma_async_tx_descriptor tx;
+};
+
+enum sba_version {
+	SBA_VER_1 = 0,
+	SBA_VER_2
+};
+
+struct sba_device {
+	/* Underlying device */
+	struct device *dev;
+	/* DT configuration parameters */
+	enum sba_version ver;
+	/* Derived configuration parameters */
+	u32 max_req;
+	u32 hw_buf_size;
+	u32 hw_resp_size;
+	u32 max_pq_coefs;
+	u32 max_pq_srcs;
+	u32 max_cmd_per_req;
+	u32 max_xor_srcs;
+	u32 max_resp_pool_size;
+	u32 max_cmds_pool_size;
+	/* Maibox client and Mailbox channels */
+	struct mbox_client client;
+	int mchans_count;
+	atomic_t mchans_current;
+	struct mbox_chan **mchans;
+	struct device *mbox_dev;
+	/* DMA device and DMA channel */
+	struct dma_device dma_dev;
+	struct dma_chan dma_chan;
+	/* DMA channel resources */
+	void *resp_base;
+	dma_addr_t resp_dma_base;
+	void *cmds_base;
+	dma_addr_t cmds_dma_base;
+	spinlock_t reqs_lock;
+	struct sba_request *reqs;
+	bool reqs_fence;
+	struct list_head reqs_alloc_list;
+	struct list_head reqs_pending_list;
+	struct list_head reqs_active_list;
+	struct list_head reqs_received_list;
+	struct list_head reqs_completed_list;
+	struct list_head reqs_aborted_list;
+	struct list_head reqs_free_list;
+	int reqs_free_count;
+};
+
+/* ====== SBA command helper routines ===== */
+
+static inline u64 __pure sba_cmd_enc(u64 cmd, u32 val, u32 shift, u32 mask)
+{
+	cmd &= ~((u64)mask << shift);
+	cmd |= ((u64)(val & mask) << shift);
+	return cmd;
+}
+
+static inline u32 __pure sba_cmd_load_c_mdata(u32 b0)
+{
+	return b0 & SBA_C_MDATA_BNUMx_MASK;
+}
+
+static inline u32 __pure sba_cmd_write_c_mdata(u32 b0)
+{
+	return b0 & SBA_C_MDATA_BNUMx_MASK;
+}
+
+static inline u32 __pure sba_cmd_xor_c_mdata(u32 b1, u32 b0)
+{
+	return (b0 & SBA_C_MDATA_BNUMx_MASK) |
+	       ((b1 & SBA_C_MDATA_BNUMx_MASK) << SBA_C_MDATA_BNUMx_SHIFT(1));
+}
+
+static inline u32 __pure sba_cmd_pq_c_mdata(u32 d, u32 b1, u32 b0)
+{
+	return (b0 & SBA_C_MDATA_BNUMx_MASK) |
+	       ((b1 & SBA_C_MDATA_BNUMx_MASK) << SBA_C_MDATA_BNUMx_SHIFT(1)) |
+	       ((d & SBA_C_MDATA_DNUM_MASK) << SBA_C_MDATA_DNUM_SHIFT);
+}
+
+/* ====== Channel resource management routines ===== */
+
+static struct sba_request *sba_alloc_request(struct sba_device *sba)
+{
+	unsigned long flags;
+	struct sba_request *req = NULL;
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+
+	req = list_first_entry_or_null(&sba->reqs_free_list,
+				       struct sba_request, node);
+	if (req) {
+		list_move_tail(&req->node, &sba->reqs_alloc_list);
+		req->state = SBA_REQUEST_STATE_ALLOCED;
+		req->fence = false;
+		req->first = req;
+		INIT_LIST_HEAD(&req->next);
+		req->next_count = 1;
+		atomic_set(&req->next_pending_count, 1);
+
+		sba->reqs_free_count--;
+
+		dma_async_tx_descriptor_init(&req->tx, &sba->dma_chan);
+	}
+
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+
+	return req;
+}
+
+/* Note: Must be called with sba->reqs_lock held */
+static void _sba_pending_request(struct sba_device *sba,
+				 struct sba_request *req)
+{
+	lockdep_assert_held(&sba->reqs_lock);
+	req->state = SBA_REQUEST_STATE_PENDING;
+	list_move_tail(&req->node, &sba->reqs_pending_list);
+	if (list_empty(&sba->reqs_active_list))
+		sba->reqs_fence = false;
+}
+
+/* Note: Must be called with sba->reqs_lock held */
+static bool _sba_active_request(struct sba_device *sba,
+				struct sba_request *req)
+{
+	lockdep_assert_held(&sba->reqs_lock);
+	if (list_empty(&sba->reqs_active_list))
+		sba->reqs_fence = false;
+	if (sba->reqs_fence)
+		return false;
+	req->state = SBA_REQUEST_STATE_ACTIVE;
+	list_move_tail(&req->node, &sba->reqs_active_list);
+	if (req->fence)
+		sba->reqs_fence = true;
+	return true;
+}
+
+/* Note: Must be called with sba->reqs_lock held */
+static void _sba_abort_request(struct sba_device *sba,
+			       struct sba_request *req)
+{
+	lockdep_assert_held(&sba->reqs_lock);
+	req->state = SBA_REQUEST_STATE_ABORTED;
+	list_move_tail(&req->node, &sba->reqs_aborted_list);
+	if (list_empty(&sba->reqs_active_list))
+		sba->reqs_fence = false;
+}
+
+/* Note: Must be called with sba->reqs_lock held */
+static void _sba_free_request(struct sba_device *sba,
+			      struct sba_request *req)
+{
+	lockdep_assert_held(&sba->reqs_lock);
+	req->state = SBA_REQUEST_STATE_FREE;
+	list_move_tail(&req->node, &sba->reqs_free_list);
+	if (list_empty(&sba->reqs_active_list))
+		sba->reqs_fence = false;
+	sba->reqs_free_count++;
+}
+
+static void sba_received_request(struct sba_request *req)
+{
+	unsigned long flags;
+	struct sba_device *sba = req->sba;
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+	req->state = SBA_REQUEST_STATE_RECEIVED;
+	list_move_tail(&req->node, &sba->reqs_received_list);
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+}
+
+static void sba_complete_chained_requests(struct sba_request *req)
+{
+	unsigned long flags;
+	struct sba_request *nreq;
+	struct sba_device *sba = req->sba;
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+
+	req->state = SBA_REQUEST_STATE_COMPLETED;
+	list_move_tail(&req->node, &sba->reqs_completed_list);
+	list_for_each_entry(nreq, &req->next, next) {
+		nreq->state = SBA_REQUEST_STATE_COMPLETED;
+		list_move_tail(&nreq->node, &sba->reqs_completed_list);
+	}
+	if (list_empty(&sba->reqs_active_list))
+		sba->reqs_fence = false;
+
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+}
+
+static void sba_free_chained_requests(struct sba_request *req)
+{
+	unsigned long flags;
+	struct sba_request *nreq;
+	struct sba_device *sba = req->sba;
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+
+	_sba_free_request(sba, req);
+	list_for_each_entry(nreq, &req->next, next)
+		_sba_free_request(sba, nreq);
+
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+}
+
+static void sba_chain_request(struct sba_request *first,
+			      struct sba_request *req)
+{
+	unsigned long flags;
+	struct sba_device *sba = req->sba;
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+
+	list_add_tail(&req->next, &first->next);
+	req->first = first;
+	first->next_count++;
+	atomic_set(&first->next_pending_count, first->next_count);
+
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+}
+
+static void sba_cleanup_nonpending_requests(struct sba_device *sba)
+{
+	unsigned long flags;
+	struct sba_request *req, *req1;
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+
+	/* Freeup all alloced request */
+	list_for_each_entry_safe(req, req1, &sba->reqs_alloc_list, node)
+		_sba_free_request(sba, req);
+
+	/* Freeup all received request */
+	list_for_each_entry_safe(req, req1, &sba->reqs_received_list, node)
+		_sba_free_request(sba, req);
+
+	/* Freeup all completed request */
+	list_for_each_entry_safe(req, req1, &sba->reqs_completed_list, node)
+		_sba_free_request(sba, req);
+
+	/* Set all active requests as aborted */
+	list_for_each_entry_safe(req, req1, &sba->reqs_active_list, node)
+		_sba_abort_request(sba, req);
+
+	/*
+	 * Note: We expect that aborted request will be eventually
+	 * freed by sba_receive_message()
+	 */
+
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+}
+
+static void sba_cleanup_pending_requests(struct sba_device *sba)
+{
+	unsigned long flags;
+	struct sba_request *req, *req1;
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+
+	/* Freeup all pending request */
+	list_for_each_entry_safe(req, req1, &sba->reqs_pending_list, node)
+		_sba_free_request(sba, req);
+
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+}
+
+/* ====== DMAENGINE callbacks ===== */
+
+static void sba_free_chan_resources(struct dma_chan *dchan)
+{
+	/*
+	 * Channel resources are pre-alloced so we just free-up
+	 * whatever we can so that we can re-use pre-alloced
+	 * channel resources next time.
+	 */
+	sba_cleanup_nonpending_requests(to_sba_device(dchan));
+}
+
+static int sba_device_terminate_all(struct dma_chan *dchan)
+{
+	/* Cleanup all pending requests */
+	sba_cleanup_pending_requests(to_sba_device(dchan));
+
+	return 0;
+}
+
+static int sba_send_mbox_request(struct sba_device *sba,
+				 struct sba_request *req)
+{
+	int mchans_idx, ret = 0;
+
+	/* Select mailbox channel in round-robin fashion */
+	mchans_idx = atomic_inc_return(&sba->mchans_current);
+	mchans_idx = mchans_idx % sba->mchans_count;
+
+	/* Send message for the request */
+	req->msg.error = 0;
+	ret = mbox_send_message(sba->mchans[mchans_idx], &req->msg);
+	if (ret < 0) {
+		dev_err(sba->dev, "send message failed with error %d", ret);
+		return ret;
+	}
+	ret = req->msg.error;
+	if (ret < 0) {
+		dev_err(sba->dev, "message error %d", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void sba_issue_pending(struct dma_chan *dchan)
+{
+	int ret;
+	unsigned long flags;
+	struct sba_request *req, *req1;
+	struct sba_device *sba = to_sba_device(dchan);
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+
+	/* Process all pending request */
+	list_for_each_entry_safe(req, req1, &sba->reqs_pending_list, node) {
+		/* Try to make request active */
+		if (!_sba_active_request(sba, req))
+			break;
+
+		/* Send request to mailbox channel */
+		spin_unlock_irqrestore(&sba->reqs_lock, flags);
+		ret = sba_send_mbox_request(sba, req);
+		spin_lock_irqsave(&sba->reqs_lock, flags);
+
+		/* If something went wrong then keep request pending */
+		if (ret < 0) {
+			_sba_pending_request(sba, req);
+			break;
+		}
+	}
+
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+}
+
+static dma_cookie_t sba_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	unsigned long flags;
+	dma_cookie_t cookie;
+	struct sba_device *sba;
+	struct sba_request *req, *nreq;
+
+	if (unlikely(!tx))
+		return -EINVAL;
+
+	sba = to_sba_device(tx->chan);
+	req = to_sba_request(tx);
+
+	/* Assign cookie and mark all chained requests pending */
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+	cookie = dma_cookie_assign(tx);
+	_sba_pending_request(sba, req);
+	list_for_each_entry(nreq, &req->next, next)
+		_sba_pending_request(sba, nreq);
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+
+	return cookie;
+}
+
+static enum dma_status sba_tx_status(struct dma_chan *dchan,
+				     dma_cookie_t cookie,
+				     struct dma_tx_state *txstate)
+{
+	int mchan_idx;
+	enum dma_status ret;
+	struct sba_device *sba = to_sba_device(dchan);
+
+	for (mchan_idx = 0; mchan_idx < sba->mchans_count; mchan_idx++)
+		mbox_client_peek_data(sba->mchans[mchan_idx]);
+
+	ret = dma_cookie_status(dchan, cookie, txstate);
+	if (ret == DMA_COMPLETE)
+		return ret;
+
+	return dma_cookie_status(dchan, cookie, txstate);
+}
+
+static void sba_fillup_interrupt_msg(struct sba_request *req,
+				     struct brcm_sba_command *cmds,
+				     struct brcm_message *msg)
+{
+	u64 cmd;
+	u32 c_mdata;
+	struct brcm_sba_command *cmdsp = cmds;
+
+	/* Type-B command to load dummy data into buf0 */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, req->sba->hw_resp_size,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	c_mdata = sba_cmd_load_c_mdata(0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_LOAD_BUFFER,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+	cmdsp->data = req->resp_dma;
+	cmdsp->data_len = req->sba->hw_resp_size;
+	cmdsp++;
+
+	/* Type-A command to write buf0 to dummy location */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, req->sba->hw_resp_size,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	cmd = sba_cmd_enc(cmd, 0x1,
+			  SBA_RESP_SHIFT, SBA_RESP_MASK);
+	c_mdata = sba_cmd_write_c_mdata(0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_WRITE_BUFFER,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+	if (req->sba->hw_resp_size) {
+		cmdsp->flags |= BRCM_SBA_CMD_HAS_RESP;
+		cmdsp->resp = req->resp_dma;
+		cmdsp->resp_len = req->sba->hw_resp_size;
+	}
+	cmdsp->flags |= BRCM_SBA_CMD_HAS_OUTPUT;
+	cmdsp->data = req->resp_dma;
+	cmdsp->data_len = req->sba->hw_resp_size;
+	cmdsp++;
+
+	/* Fillup brcm_message */
+	msg->type = BRCM_MESSAGE_SBA;
+	msg->sba.cmds = cmds;
+	msg->sba.cmds_count = cmdsp - cmds;
+	msg->ctx = req;
+	msg->error = 0;
+}
+
+static struct dma_async_tx_descriptor *
+sba_prep_dma_interrupt(struct dma_chan *dchan, unsigned long flags)
+{
+	struct sba_request *req = NULL;
+	struct sba_device *sba = to_sba_device(dchan);
+
+	/* Alloc new request */
+	req = sba_alloc_request(sba);
+	if (!req)
+		return NULL;
+
+	/*
+	 * Force fence so that no requests are submitted
+	 * until DMA callback for this request is invoked.
+	 */
+	req->fence = true;
+
+	/* Fillup request message */
+	sba_fillup_interrupt_msg(req, req->cmds, &req->msg);
+
+	/* Init async_tx descriptor */
+	req->tx.flags = flags;
+	req->tx.cookie = -EBUSY;
+
+	return &req->tx;
+}
+
+static void sba_fillup_memcpy_msg(struct sba_request *req,
+				  struct brcm_sba_command *cmds,
+				  struct brcm_message *msg,
+				  dma_addr_t msg_offset, size_t msg_len,
+				  dma_addr_t dst, dma_addr_t src)
+{
+	u64 cmd;
+	u32 c_mdata;
+	struct brcm_sba_command *cmdsp = cmds;
+
+	/* Type-B command to load data into buf0 */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, msg_len,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	c_mdata = sba_cmd_load_c_mdata(0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_LOAD_BUFFER,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+	cmdsp->data = src + msg_offset;
+	cmdsp->data_len = msg_len;
+	cmdsp++;
+
+	/* Type-A command to write buf0 */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, msg_len,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	cmd = sba_cmd_enc(cmd, 0x1,
+			  SBA_RESP_SHIFT, SBA_RESP_MASK);
+	c_mdata = sba_cmd_write_c_mdata(0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_WRITE_BUFFER,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+	if (req->sba->hw_resp_size) {
+		cmdsp->flags |= BRCM_SBA_CMD_HAS_RESP;
+		cmdsp->resp = req->resp_dma;
+		cmdsp->resp_len = req->sba->hw_resp_size;
+	}
+	cmdsp->flags |= BRCM_SBA_CMD_HAS_OUTPUT;
+	cmdsp->data = dst + msg_offset;
+	cmdsp->data_len = msg_len;
+	cmdsp++;
+
+	/* Fillup brcm_message */
+	msg->type = BRCM_MESSAGE_SBA;
+	msg->sba.cmds = cmds;
+	msg->sba.cmds_count = cmdsp - cmds;
+	msg->ctx = req;
+	msg->error = 0;
+}
+
+static struct sba_request *
+sba_prep_dma_memcpy_req(struct sba_device *sba,
+			dma_addr_t off, dma_addr_t dst, dma_addr_t src,
+			size_t len, unsigned long flags)
+{
+	struct sba_request *req = NULL;
+
+	/* Alloc new request */
+	req = sba_alloc_request(sba);
+	if (!req)
+		return NULL;
+	req->fence = (flags & DMA_PREP_FENCE) ? true : false;
+
+	/* Fillup request message */
+	sba_fillup_memcpy_msg(req, req->cmds, &req->msg,
+			      off, len, dst, src);
+
+	/* Init async_tx descriptor */
+	req->tx.flags = flags;
+	req->tx.cookie = -EBUSY;
+
+	return req;
+}
+
+static struct dma_async_tx_descriptor *
+sba_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
+		    size_t len, unsigned long flags)
+{
+	size_t req_len;
+	dma_addr_t off = 0;
+	struct sba_device *sba = to_sba_device(dchan);
+	struct sba_request *first = NULL, *req;
+
+	/* Create chained requests where each request is upto hw_buf_size */
+	while (len) {
+		req_len = (len < sba->hw_buf_size) ? len : sba->hw_buf_size;
+
+		req = sba_prep_dma_memcpy_req(sba, off, dst, src,
+					      req_len, flags);
+		if (!req) {
+			if (first)
+				sba_free_chained_requests(first);
+			return NULL;
+		}
+
+		if (first)
+			sba_chain_request(first, req);
+		else
+			first = req;
+
+		off += req_len;
+		len -= req_len;
+	}
+
+	return (first) ? &first->tx : NULL;
+}
+
+static void sba_fillup_xor_msg(struct sba_request *req,
+				struct brcm_sba_command *cmds,
+				struct brcm_message *msg,
+				dma_addr_t msg_offset, size_t msg_len,
+				dma_addr_t dst, dma_addr_t *src, u32 src_cnt)
+{
+	u64 cmd;
+	u32 c_mdata;
+	unsigned int i;
+	struct brcm_sba_command *cmdsp = cmds;
+
+	/* Type-B command to load data into buf0 */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, msg_len,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	c_mdata = sba_cmd_load_c_mdata(0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_LOAD_BUFFER,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+	cmdsp->data = src[0] + msg_offset;
+	cmdsp->data_len = msg_len;
+	cmdsp++;
+
+	/* Type-B commands to xor data with buf0 and put it back in buf0 */
+	for (i = 1; i < src_cnt; i++) {
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		c_mdata = sba_cmd_xor_c_mdata(0, 0);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_XOR,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+		cmdsp->data = src[i] + msg_offset;
+		cmdsp->data_len = msg_len;
+		cmdsp++;
+	}
+
+	/* Type-A command to write buf0 */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, msg_len,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	cmd = sba_cmd_enc(cmd, 0x1,
+			  SBA_RESP_SHIFT, SBA_RESP_MASK);
+	c_mdata = sba_cmd_write_c_mdata(0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_WRITE_BUFFER,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+	if (req->sba->hw_resp_size) {
+		cmdsp->flags |= BRCM_SBA_CMD_HAS_RESP;
+		cmdsp->resp = req->resp_dma;
+		cmdsp->resp_len = req->sba->hw_resp_size;
+	}
+	cmdsp->flags |= BRCM_SBA_CMD_HAS_OUTPUT;
+	cmdsp->data = dst + msg_offset;
+	cmdsp->data_len = msg_len;
+	cmdsp++;
+
+	/* Fillup brcm_message */
+	msg->type = BRCM_MESSAGE_SBA;
+	msg->sba.cmds = cmds;
+	msg->sba.cmds_count = cmdsp - cmds;
+	msg->ctx = req;
+	msg->error = 0;
+}
+
+struct sba_request *
+sba_prep_dma_xor_req(struct sba_device *sba,
+		     dma_addr_t off, dma_addr_t dst, dma_addr_t *src,
+		     u32 src_cnt, size_t len, unsigned long flags)
+{
+	struct sba_request *req = NULL;
+
+	/* Alloc new request */
+	req = sba_alloc_request(sba);
+	if (!req)
+		return NULL;
+	req->fence = (flags & DMA_PREP_FENCE) ? true : false;
+
+	/* Fillup request message */
+	sba_fillup_xor_msg(req, req->cmds, &req->msg,
+			   off, len, dst, src, src_cnt);
+
+	/* Init async_tx descriptor */
+	req->tx.flags = flags;
+	req->tx.cookie = -EBUSY;
+
+	return req;
+}
+
+static struct dma_async_tx_descriptor *
+sba_prep_dma_xor(struct dma_chan *dchan, dma_addr_t dst, dma_addr_t *src,
+		 u32 src_cnt, size_t len, unsigned long flags)
+{
+	size_t req_len;
+	dma_addr_t off = 0;
+	struct sba_device *sba = to_sba_device(dchan);
+	struct sba_request *first = NULL, *req;
+
+	/* Sanity checks */
+	if (unlikely(src_cnt > sba->max_xor_srcs))
+		return NULL;
+
+	/* Create chained requests where each request is upto hw_buf_size */
+	while (len) {
+		req_len = (len < sba->hw_buf_size) ? len : sba->hw_buf_size;
+
+		req = sba_prep_dma_xor_req(sba, off, dst, src, src_cnt,
+					   req_len, flags);
+		if (!req) {
+			if (first)
+				sba_free_chained_requests(first);
+			return NULL;
+		}
+
+		if (first)
+			sba_chain_request(first, req);
+		else
+			first = req;
+
+		off += req_len;
+		len -= req_len;
+	}
+
+	return (first) ? &first->tx : NULL;
+}
+
+static void sba_fillup_pq_msg(struct sba_request *req,
+				bool pq_continue,
+				struct brcm_sba_command *cmds,
+				struct brcm_message *msg,
+				dma_addr_t msg_offset, size_t msg_len,
+				dma_addr_t *dst_p, dma_addr_t *dst_q,
+				const u8 *scf, dma_addr_t *src, u32 src_cnt)
+{
+	u64 cmd;
+	u32 c_mdata;
+	unsigned int i;
+	struct brcm_sba_command *cmdsp = cmds;
+
+	if (pq_continue) {
+		/* Type-B command to load old P into buf0 */
+		if (dst_p) {
+			cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+				SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+			cmd = sba_cmd_enc(cmd, msg_len,
+				SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+			c_mdata = sba_cmd_load_c_mdata(0);
+			cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+			cmd = sba_cmd_enc(cmd, SBA_CMD_LOAD_BUFFER,
+				SBA_CMD_SHIFT, SBA_CMD_MASK);
+			cmdsp->cmd = cmd;
+			*cmdsp->cmd_dma = cpu_to_le64(cmd);
+			cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+			cmdsp->data = *dst_p + msg_offset;
+			cmdsp->data_len = msg_len;
+			cmdsp++;
+		}
+
+		/* Type-B command to load old Q into buf1 */
+		if (dst_q) {
+			cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+				SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+			cmd = sba_cmd_enc(cmd, msg_len,
+				SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+			c_mdata = sba_cmd_load_c_mdata(1);
+			cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+			cmd = sba_cmd_enc(cmd, SBA_CMD_LOAD_BUFFER,
+				SBA_CMD_SHIFT, SBA_CMD_MASK);
+			cmdsp->cmd = cmd;
+			*cmdsp->cmd_dma = cpu_to_le64(cmd);
+			cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+			cmdsp->data = *dst_q + msg_offset;
+			cmdsp->data_len = msg_len;
+			cmdsp++;
+		}
+	} else {
+		/* Type-A command to zero all buffers */
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_ZERO_ALL_BUFFERS,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+		cmdsp++;
+	}
+
+	/* Type-B commands for generate P onto buf0 and Q onto buf1 */
+	for (i = 0; i < src_cnt; i++) {
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		c_mdata = sba_cmd_pq_c_mdata(raid6_gflog[scf[i]], 1, 0);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_MS(c_mdata),
+				  SBA_C_MDATA_MS_SHIFT, SBA_C_MDATA_MS_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_GALOIS_XOR,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+		cmdsp->data = src[i] + msg_offset;
+		cmdsp->data_len = msg_len;
+		cmdsp++;
+	}
+
+	/* Type-A command to write buf0 */
+	if (dst_p) {
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		cmd = sba_cmd_enc(cmd, 0x1,
+				  SBA_RESP_SHIFT, SBA_RESP_MASK);
+		c_mdata = sba_cmd_write_c_mdata(0);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_WRITE_BUFFER,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+		if (req->sba->hw_resp_size) {
+			cmdsp->flags |= BRCM_SBA_CMD_HAS_RESP;
+			cmdsp->resp = req->resp_dma;
+			cmdsp->resp_len = req->sba->hw_resp_size;
+		}
+		cmdsp->flags |= BRCM_SBA_CMD_HAS_OUTPUT;
+		cmdsp->data = *dst_p + msg_offset;
+		cmdsp->data_len = msg_len;
+		cmdsp++;
+	}
+
+	/* Type-A command to write buf1 */
+	if (dst_q) {
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		cmd = sba_cmd_enc(cmd, 0x1,
+				  SBA_RESP_SHIFT, SBA_RESP_MASK);
+		c_mdata = sba_cmd_write_c_mdata(1);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_WRITE_BUFFER,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+		if (req->sba->hw_resp_size) {
+			cmdsp->flags |= BRCM_SBA_CMD_HAS_RESP;
+			cmdsp->resp = req->resp_dma;
+			cmdsp->resp_len = req->sba->hw_resp_size;
+		}
+		cmdsp->flags |= BRCM_SBA_CMD_HAS_OUTPUT;
+		cmdsp->data = *dst_q + msg_offset;
+		cmdsp->data_len = msg_len;
+		cmdsp++;
+	}
+
+	/* Fillup brcm_message */
+	msg->type = BRCM_MESSAGE_SBA;
+	msg->sba.cmds = cmds;
+	msg->sba.cmds_count = cmdsp - cmds;
+	msg->ctx = req;
+	msg->error = 0;
+}
+
+struct sba_request *
+sba_prep_dma_pq_req(struct sba_device *sba, dma_addr_t off,
+		    dma_addr_t *dst_p, dma_addr_t *dst_q, dma_addr_t *src,
+		    u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
+{
+	struct sba_request *req = NULL;
+
+	/* Alloc new request */
+	req = sba_alloc_request(sba);
+	if (!req)
+		return NULL;
+	req->fence = (flags & DMA_PREP_FENCE) ? true : false;
+
+	/* Fillup request messages */
+	sba_fillup_pq_msg(req, dmaf_continue(flags),
+			  req->cmds, &req->msg,
+			  off, len, dst_p, dst_q, scf, src, src_cnt);
+
+	/* Init async_tx descriptor */
+	req->tx.flags = flags;
+	req->tx.cookie = -EBUSY;
+
+	return req;
+}
+
+static void sba_fillup_pq_single_msg(struct sba_request *req,
+				bool pq_continue,
+				struct brcm_sba_command *cmds,
+				struct brcm_message *msg,
+				dma_addr_t msg_offset, size_t msg_len,
+				dma_addr_t *dst_p, dma_addr_t *dst_q,
+				dma_addr_t src, u8 scf)
+{
+	u64 cmd;
+	u32 c_mdata;
+	u8 pos, dpos = raid6_gflog[scf];
+	struct brcm_sba_command *cmdsp = cmds;
+
+	if (!dst_p)
+		goto skip_p;
+
+	if (pq_continue) {
+		/* Type-B command to load old P into buf0 */
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		c_mdata = sba_cmd_load_c_mdata(0);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_LOAD_BUFFER,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+		cmdsp->data = *dst_p + msg_offset;
+		cmdsp->data_len = msg_len;
+		cmdsp++;
+
+		/*
+		 * Type-B commands to xor data with buf0 and put it
+		 * back in buf0
+		 */
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		c_mdata = sba_cmd_xor_c_mdata(0, 0);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_XOR,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+		cmdsp->data = src + msg_offset;
+		cmdsp->data_len = msg_len;
+		cmdsp++;
+	} else {
+		/* Type-B command to load old P into buf0 */
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		c_mdata = sba_cmd_load_c_mdata(0);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_LOAD_BUFFER,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+		cmdsp->data = src + msg_offset;
+		cmdsp->data_len = msg_len;
+		cmdsp++;
+	}
+
+	/* Type-A command to write buf0 */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, msg_len,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	cmd = sba_cmd_enc(cmd, 0x1,
+			  SBA_RESP_SHIFT, SBA_RESP_MASK);
+	c_mdata = sba_cmd_write_c_mdata(0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_WRITE_BUFFER,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+	if (req->sba->hw_resp_size) {
+		cmdsp->flags |= BRCM_SBA_CMD_HAS_RESP;
+		cmdsp->resp = req->resp_dma;
+		cmdsp->resp_len = req->sba->hw_resp_size;
+	}
+	cmdsp->flags |= BRCM_SBA_CMD_HAS_OUTPUT;
+	cmdsp->data = *dst_p + msg_offset;
+	cmdsp->data_len = msg_len;
+	cmdsp++;
+
+skip_p:
+	if (!dst_q)
+		goto skip_q;
+
+	/* Type-A command to zero all buffers */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, msg_len,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_ZERO_ALL_BUFFERS,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+	cmdsp++;
+
+	if (dpos == 255)
+		goto skip_q_computation;
+	pos = (dpos < req->sba->max_pq_coefs) ?
+		dpos : (req->sba->max_pq_coefs - 1);
+
+	/*
+	 * Type-B command to generate initial Q from data
+	 * and store output into buf0
+	 */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, msg_len,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	c_mdata = sba_cmd_pq_c_mdata(pos, 0, 0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_MS(c_mdata),
+			  SBA_C_MDATA_MS_SHIFT, SBA_C_MDATA_MS_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_GALOIS,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+	cmdsp->data = src + msg_offset;
+	cmdsp->data_len = msg_len;
+	cmdsp++;
+
+	dpos -= pos;
+
+	/* Multiple Type-A command to generate final Q */
+	while (dpos) {
+		pos = (dpos < req->sba->max_pq_coefs) ?
+			dpos : (req->sba->max_pq_coefs - 1);
+
+		/*
+		 * Type-A command to generate Q with buf0 and
+		 * buf1 store result in buf0
+		 */
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		c_mdata = sba_cmd_pq_c_mdata(pos, 0, 1);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_MS(c_mdata),
+				  SBA_C_MDATA_MS_SHIFT, SBA_C_MDATA_MS_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_GALOIS,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+		cmdsp++;
+
+		dpos -= pos;
+	}
+
+skip_q_computation:
+	if (pq_continue) {
+		/*
+		 * Type-B command to XOR previous output with
+		 * buf0 and write it into buf0
+		 */
+		cmd = sba_cmd_enc(0x0, SBA_TYPE_B,
+				  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+		cmd = sba_cmd_enc(cmd, msg_len,
+				  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+		c_mdata = sba_cmd_xor_c_mdata(0, 0);
+		cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+				  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+		cmd = sba_cmd_enc(cmd, SBA_CMD_XOR,
+				  SBA_CMD_SHIFT, SBA_CMD_MASK);
+		cmdsp->cmd = cmd;
+		*cmdsp->cmd_dma = cpu_to_le64(cmd);
+		cmdsp->flags = BRCM_SBA_CMD_TYPE_B;
+		cmdsp->data = *dst_q + msg_offset;
+		cmdsp->data_len = msg_len;
+		cmdsp++;
+	}
+
+	/* Type-A command to write buf0 */
+	cmd = sba_cmd_enc(0x0, SBA_TYPE_A,
+			  SBA_TYPE_SHIFT, SBA_TYPE_MASK);
+	cmd = sba_cmd_enc(cmd, msg_len,
+			  SBA_USER_DEF_SHIFT, SBA_USER_DEF_MASK);
+	cmd = sba_cmd_enc(cmd, 0x1,
+			  SBA_RESP_SHIFT, SBA_RESP_MASK);
+	c_mdata = sba_cmd_write_c_mdata(0);
+	cmd = sba_cmd_enc(cmd, SBA_C_MDATA_LS(c_mdata),
+			  SBA_C_MDATA_SHIFT, SBA_C_MDATA_MASK);
+	cmd = sba_cmd_enc(cmd, SBA_CMD_WRITE_BUFFER,
+			  SBA_CMD_SHIFT, SBA_CMD_MASK);
+	cmdsp->cmd = cmd;
+	*cmdsp->cmd_dma = cpu_to_le64(cmd);
+	cmdsp->flags = BRCM_SBA_CMD_TYPE_A;
+	if (req->sba->hw_resp_size) {
+		cmdsp->flags |= BRCM_SBA_CMD_HAS_RESP;
+		cmdsp->resp = req->resp_dma;
+		cmdsp->resp_len = req->sba->hw_resp_size;
+	}
+	cmdsp->flags |= BRCM_SBA_CMD_HAS_OUTPUT;
+	cmdsp->data = *dst_q + msg_offset;
+	cmdsp->data_len = msg_len;
+	cmdsp++;
+
+skip_q:
+	/* Fillup brcm_message */
+	msg->type = BRCM_MESSAGE_SBA;
+	msg->sba.cmds = cmds;
+	msg->sba.cmds_count = cmdsp - cmds;
+	msg->ctx = req;
+	msg->error = 0;
+}
+
+struct sba_request *
+sba_prep_dma_pq_single_req(struct sba_device *sba, dma_addr_t off,
+			   dma_addr_t *dst_p, dma_addr_t *dst_q,
+			   dma_addr_t src, u8 scf, size_t len,
+			   unsigned long flags)
+{
+	struct sba_request *req = NULL;
+
+	/* Alloc new request */
+	req = sba_alloc_request(sba);
+	if (!req)
+		return NULL;
+	req->fence = (flags & DMA_PREP_FENCE) ? true : false;
+
+	/* Fillup request messages */
+	sba_fillup_pq_single_msg(req,  dmaf_continue(flags),
+				 req->cmds, &req->msg, off, len,
+				 dst_p, dst_q, src, scf);
+
+	/* Init async_tx descriptor */
+	req->tx.flags = flags;
+	req->tx.cookie = -EBUSY;
+
+	return req;
+}
+
+static struct dma_async_tx_descriptor *
+sba_prep_dma_pq(struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
+		u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
+{
+	u32 i, dst_q_index;
+	size_t req_len;
+	bool slow = false;
+	dma_addr_t off = 0;
+	dma_addr_t *dst_p = NULL, *dst_q = NULL;
+	struct sba_device *sba = to_sba_device(dchan);
+	struct sba_request *first = NULL, *req;
+
+	/* Sanity checks */
+	if (unlikely(src_cnt > sba->max_pq_srcs))
+		return NULL;
+	for (i = 0; i < src_cnt; i++)
+		if (sba->max_pq_coefs <= raid6_gflog[scf[i]])
+			slow = true;
+
+	/* Figure-out P and Q destination addresses */
+	if (!(flags & DMA_PREP_PQ_DISABLE_P))
+		dst_p = &dst[0];
+	if (!(flags & DMA_PREP_PQ_DISABLE_Q))
+		dst_q = &dst[1];
+
+	/* Create chained requests where each request is upto hw_buf_size */
+	while (len) {
+		req_len = (len < sba->hw_buf_size) ? len : sba->hw_buf_size;
+
+		if (slow) {
+			dst_q_index = src_cnt;
+
+			if (dst_q) {
+				for (i = 0; i < src_cnt; i++) {
+					if (*dst_q == src[i]) {
+						dst_q_index = i;
+						break;
+					}
+				}
+			}
+
+			if (dst_q_index < src_cnt) {
+				i = dst_q_index;
+				req = sba_prep_dma_pq_single_req(sba,
+					off, dst_p, dst_q, src[i], scf[i],
+					req_len, flags | DMA_PREP_FENCE);
+				if (!req)
+					goto fail;
+
+				if (first)
+					sba_chain_request(first, req);
+				else
+					first = req;
+
+				flags |= DMA_PREP_CONTINUE;
+			}
+
+			for (i = 0; i < src_cnt; i++) {
+				if (dst_q_index == i)
+					continue;
+
+				req = sba_prep_dma_pq_single_req(sba,
+					off, dst_p, dst_q, src[i], scf[i],
+					req_len, flags | DMA_PREP_FENCE);
+				if (!req)
+					goto fail;
+
+				if (first)
+					sba_chain_request(first, req);
+				else
+					first = req;
+
+				flags |= DMA_PREP_CONTINUE;
+			}
+		} else {
+			req = sba_prep_dma_pq_req(sba, off,
+						  dst_p, dst_q, src, src_cnt,
+						  scf, req_len, flags);
+			if (!req)
+				goto fail;
+
+			if (first)
+				sba_chain_request(first, req);
+			else
+				first = req;
+		}
+
+		off += req_len;
+		len -= req_len;
+	}
+
+	return (first) ? &first->tx : NULL;
+
+fail:
+	if (first)
+		sba_free_chained_requests(first);
+	return NULL;
+}
+
+/* ====== Mailbox callbacks ===== */
+
+static void sba_dma_tx_actions(struct sba_request *req)
+{
+	struct dma_async_tx_descriptor *tx = &req->tx;
+
+	WARN_ON(tx->cookie < 0);
+
+	if (tx->cookie > 0) {
+		dma_cookie_complete(tx);
+
+		/*
+		 * Call the callback (must not sleep or submit new
+		 * operations to this channel)
+		 */
+		if (tx->callback)
+			tx->callback(tx->callback_param);
+
+		dma_descriptor_unmap(tx);
+	}
+
+	/* Run dependent operations */
+	dma_run_dependencies(tx);
+
+	/* If waiting for 'ack' then move to completed list */
+	if (!async_tx_test_ack(&req->tx))
+		sba_complete_chained_requests(req);
+	else
+		sba_free_chained_requests(req);
+}
+
+static void sba_receive_message(struct mbox_client *cl, void *msg)
+{
+	unsigned long flags;
+	struct brcm_message *m = msg;
+	struct sba_request *req = m->ctx, *req1;
+	struct sba_device *sba = req->sba;
+
+	/* Error count if message has error */
+	if (m->error < 0)
+		dev_err(sba->dev, "%s got message with error %d",
+			dma_chan_name(&sba->dma_chan), m->error);
+
+	/* Mark request as received */
+	sba_received_request(req);
+
+	/* Wait for all chained requests to be completed */
+	if (atomic_dec_return(&req->first->next_pending_count))
+		goto done;
+
+	/* Point to first request */
+	req = req->first;
+
+	/* Update request */
+	if (req->state == SBA_REQUEST_STATE_RECEIVED)
+		sba_dma_tx_actions(req);
+	else
+		sba_free_chained_requests(req);
+
+	spin_lock_irqsave(&sba->reqs_lock, flags);
+
+	/* Re-check all completed request waiting for 'ack' */
+	list_for_each_entry_safe(req, req1, &sba->reqs_completed_list, node) {
+		spin_unlock_irqrestore(&sba->reqs_lock, flags);
+		sba_dma_tx_actions(req);
+		spin_lock_irqsave(&sba->reqs_lock, flags);
+	}
+
+	spin_unlock_irqrestore(&sba->reqs_lock, flags);
+
+done:
+	/* Try to submit pending request */
+	sba_issue_pending(&sba->dma_chan);
+}
+
+/* ====== Platform driver routines ===== */
+
+static int sba_prealloc_channel_resources(struct sba_device *sba)
+{
+	int i, j, p, ret = 0;
+	struct sba_request *req = NULL;
+
+	sba->resp_base = dma_alloc_coherent(sba->dma_dev.dev,
+					    sba->max_resp_pool_size,
+					    &sba->resp_dma_base, GFP_KERNEL);
+	if (!sba->resp_base)
+		return -ENOMEM;
+
+	sba->cmds_base = dma_alloc_coherent(sba->dma_dev.dev,
+					    sba->max_cmds_pool_size,
+					    &sba->cmds_dma_base, GFP_KERNEL);
+	if (!sba->cmds_base) {
+		ret = -ENOMEM;
+		goto fail_free_resp_pool;
+	}
+
+	spin_lock_init(&sba->reqs_lock);
+	sba->reqs_fence = false;
+	INIT_LIST_HEAD(&sba->reqs_alloc_list);
+	INIT_LIST_HEAD(&sba->reqs_pending_list);
+	INIT_LIST_HEAD(&sba->reqs_active_list);
+	INIT_LIST_HEAD(&sba->reqs_received_list);
+	INIT_LIST_HEAD(&sba->reqs_completed_list);
+	INIT_LIST_HEAD(&sba->reqs_aborted_list);
+	INIT_LIST_HEAD(&sba->reqs_free_list);
+
+	sba->reqs = devm_kcalloc(sba->dev, sba->max_req,
+				 sizeof(*req), GFP_KERNEL);
+	if (!sba->reqs) {
+		ret = -ENOMEM;
+		goto fail_free_cmds_pool;
+	}
+
+	for (i = 0, p = 0; i < sba->max_req; i++) {
+		req = &sba->reqs[i];
+		INIT_LIST_HEAD(&req->node);
+		req->sba = sba;
+		req->state = SBA_REQUEST_STATE_FREE;
+		INIT_LIST_HEAD(&req->next);
+		req->next_count = 1;
+		atomic_set(&req->next_pending_count, 0);
+		req->fence = false;
+		req->resp = sba->resp_base + p;
+		req->resp_dma = sba->resp_dma_base + p;
+		p += sba->hw_resp_size;
+		req->cmds = devm_kcalloc(sba->dev, sba->max_cmd_per_req,
+					 sizeof(*req->cmds), GFP_KERNEL);
+		if (!req->cmds) {
+			ret = -ENOMEM;
+			goto fail_free_cmds_pool;
+		}
+		for (j = 0; j < sba->max_cmd_per_req; j++) {
+			req->cmds[j].cmd = 0;
+			req->cmds[j].cmd_dma = sba->cmds_base +
+				(i * sba->max_cmd_per_req + j) * sizeof(u64);
+			req->cmds[j].cmd_dma_addr = sba->cmds_dma_base +
+				(i * sba->max_cmd_per_req + j) * sizeof(u64);
+			req->cmds[j].flags = 0;
+		}
+		memset(&req->msg, 0, sizeof(req->msg));
+		dma_async_tx_descriptor_init(&req->tx, &sba->dma_chan);
+		req->tx.tx_submit = sba_tx_submit;
+		req->tx.phys = req->resp_dma;
+		list_add_tail(&req->node, &sba->reqs_free_list);
+	}
+
+	sba->reqs_free_count = sba->max_req;
+
+	return 0;
+
+fail_free_cmds_pool:
+	dma_free_coherent(sba->dma_dev.dev,
+			  sba->max_cmds_pool_size,
+			  sba->cmds_base, sba->cmds_dma_base);
+fail_free_resp_pool:
+	dma_free_coherent(sba->dma_dev.dev,
+			  sba->max_resp_pool_size,
+			  sba->resp_base, sba->resp_dma_base);
+	return ret;
+}
+
+static void sba_freeup_channel_resources(struct sba_device *sba)
+{
+	dmaengine_terminate_all(&sba->dma_chan);
+	dma_free_coherent(sba->dma_dev.dev, sba->max_cmds_pool_size,
+			  sba->cmds_base, sba->cmds_dma_base);
+	dma_free_coherent(sba->dma_dev.dev, sba->max_resp_pool_size,
+			  sba->resp_base, sba->resp_dma_base);
+	sba->resp_base = NULL;
+	sba->resp_dma_base = 0;
+}
+
+static int sba_async_register(struct sba_device *sba)
+{
+	int ret;
+	struct dma_device *dma_dev = &sba->dma_dev;
+
+	/* Initialize DMA channel cookie */
+	sba->dma_chan.device = dma_dev;
+	dma_cookie_init(&sba->dma_chan);
+
+	/* Initialize DMA device capability mask */
+	dma_cap_zero(dma_dev->cap_mask);
+	dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask);
+	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
+	dma_cap_set(DMA_XOR, dma_dev->cap_mask);
+	dma_cap_set(DMA_PQ, dma_dev->cap_mask);
+
+	/*
+	 * Set mailbox channel device as the base device of
+	 * our dma_device because the actual memory accesses
+	 * will be done by mailbox controller
+	 */
+	dma_dev->dev = sba->mbox_dev;
+
+	/* Set base prep routines */
+	dma_dev->device_free_chan_resources = sba_free_chan_resources;
+	dma_dev->device_terminate_all = sba_device_terminate_all;
+	dma_dev->device_issue_pending = sba_issue_pending;
+	dma_dev->device_tx_status = sba_tx_status;
+
+	/* Set interrupt routine */
+	if (dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask))
+		dma_dev->device_prep_dma_interrupt = sba_prep_dma_interrupt;
+
+	/* Set memcpy routine */
+	if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask))
+		dma_dev->device_prep_dma_memcpy = sba_prep_dma_memcpy;
+
+	/* Set xor routine and capability */
+	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
+		dma_dev->device_prep_dma_xor = sba_prep_dma_xor;
+		dma_dev->max_xor = sba->max_xor_srcs;
+	}
+
+	/* Set pq routine and capability */
+	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
+		dma_dev->device_prep_dma_pq = sba_prep_dma_pq;
+		dma_set_maxpq(dma_dev, sba->max_pq_srcs, 0);
+	}
+
+	/* Initialize DMA device channel list */
+	INIT_LIST_HEAD(&dma_dev->channels);
+	list_add_tail(&sba->dma_chan.device_node, &dma_dev->channels);
+
+	/* Register with Linux async DMA framework*/
+	ret = dma_async_device_register(dma_dev);
+	if (ret) {
+		dev_err(sba->dev, "async device register error %d", ret);
+		return ret;
+	}
+
+	dev_info(sba->dev, "%s capabilities: %s%s%s%s\n",
+	dma_chan_name(&sba->dma_chan),
+	dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask) ? "interrupt " : "",
+	dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "memcpy " : "",
+	dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "xor " : "",
+	dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "pq " : "");
+
+	return 0;
+}
+
+static int sba_probe(struct platform_device *pdev)
+{
+	int i, ret = 0, mchans_count;
+	struct sba_device *sba;
+	struct platform_device *mbox_pdev;
+	struct of_phandle_args args;
+
+	/* Allocate main SBA struct */
+	sba = devm_kzalloc(&pdev->dev, sizeof(*sba), GFP_KERNEL);
+	if (!sba)
+		return -ENOMEM;
+
+	sba->dev = &pdev->dev;
+	platform_set_drvdata(pdev, sba);
+
+	/* Determine SBA version from DT compatible string */
+	if (of_device_is_compatible(sba->dev->of_node, "brcm,iproc-sba"))
+		sba->ver = SBA_VER_1;
+	else if (of_device_is_compatible(sba->dev->of_node,
+					 "brcm,iproc-sba-v2"))
+		sba->ver = SBA_VER_2;
+	else
+		return -ENODEV;
+
+	/* Derived Configuration parameters */
+	switch (sba->ver) {
+	case SBA_VER_1:
+		sba->max_req = 1024;
+		sba->hw_buf_size = 4096;
+		sba->hw_resp_size = 8;
+		sba->max_pq_coefs = 6;
+		sba->max_pq_srcs = 6;
+		break;
+	case SBA_VER_2:
+		sba->max_req = 1024;
+		sba->hw_buf_size = 4096;
+		sba->hw_resp_size = 8;
+		sba->max_pq_coefs = 30;
+		/*
+		 * We can support max_pq_srcs == max_pq_coefs because
+		 * we are limited by number of SBA commands that we can
+		 * fit in one message for underlying ring manager HW.
+		 */
+		sba->max_pq_srcs = 12;
+		break;
+	default:
+		return -EINVAL;
+	}
+	sba->max_cmd_per_req = sba->max_pq_srcs + 3;
+	sba->max_xor_srcs = sba->max_cmd_per_req - 1;
+	sba->max_resp_pool_size = sba->max_req * sba->hw_resp_size;
+	sba->max_cmds_pool_size = sba->max_req *
+				  sba->max_cmd_per_req * sizeof(u64);
+
+	/* Setup mailbox client */
+	sba->client.dev			= &pdev->dev;
+	sba->client.rx_callback		= sba_receive_message;
+	sba->client.tx_block		= false;
+	sba->client.knows_txdone	= false;
+	sba->client.tx_tout		= 0;
+
+	/* Number of channels equals number of mailbox channels */
+	ret = of_count_phandle_with_args(pdev->dev.of_node,
+					 "mboxes", "#mbox-cells");
+	if (ret <= 0)
+		return -ENODEV;
+	mchans_count = ret;
+	sba->mchans_count = 0;
+	atomic_set(&sba->mchans_current, 0);
+
+	/* Allocate mailbox channel array */
+	sba->mchans = devm_kcalloc(&pdev->dev, sba->mchans_count,
+				   sizeof(*sba->mchans), GFP_KERNEL);
+	if (!sba->mchans)
+		return -ENOMEM;
+
+	/* Request mailbox channels */
+	for (i = 0; i < mchans_count; i++) {
+		sba->mchans[i] = mbox_request_channel(&sba->client, i);
+		if (IS_ERR(sba->mchans[i])) {
+			ret = PTR_ERR(sba->mchans[i]);
+			goto fail_free_mchans;
+		}
+		sba->mchans_count++;
+	}
+
+	/* Find-out underlying mailbox device */
+	ret = of_parse_phandle_with_args(pdev->dev.of_node,
+					 "mboxes", "#mbox-cells", 0, &args);
+	if (ret)
+		goto fail_free_mchans;
+	mbox_pdev = of_find_device_by_node(args.np);
+	of_node_put(args.np);
+	if (!mbox_pdev) {
+		ret = -ENODEV;
+		goto fail_free_mchans;
+	}
+	sba->mbox_dev = &mbox_pdev->dev;
+
+	/* All mailbox channels should be of same ring manager device */
+	for (i = 1; i < mchans_count; i++) {
+		ret = of_parse_phandle_with_args(pdev->dev.of_node,
+					 "mboxes", "#mbox-cells", i, &args);
+		if (ret)
+			goto fail_free_mchans;
+		mbox_pdev = of_find_device_by_node(args.np);
+		of_node_put(args.np);
+		if (sba->mbox_dev != &mbox_pdev->dev) {
+			ret = -EINVAL;
+			goto fail_free_mchans;
+		}
+	}
+
+	/* Register DMA device with linux async framework */
+	ret = sba_async_register(sba);
+	if (ret)
+		goto fail_free_mchans;
+
+	/* Prealloc channel resource */
+	ret = sba_prealloc_channel_resources(sba);
+	if (ret)
+		goto fail_async_dev_unreg;
+
+	/* Print device info */
+	dev_info(sba->dev, "%s using SBAv%d and %d mailbox channels",
+		 dma_chan_name(&sba->dma_chan), sba->ver+1,
+		 sba->mchans_count);
+
+	return 0;
+
+fail_async_dev_unreg:
+	dma_async_device_unregister(&sba->dma_dev);
+fail_free_mchans:
+	for (i = 0; i < sba->mchans_count; i++)
+		mbox_free_channel(sba->mchans[i]);
+	return ret;
+}
+
+static int sba_remove(struct platform_device *pdev)
+{
+	int i;
+	struct sba_device *sba = platform_get_drvdata(pdev);
+
+	sba_freeup_channel_resources(sba);
+
+	dma_async_device_unregister(&sba->dma_dev);
+
+	for (i = 0; i < sba->mchans_count; i++)
+		mbox_free_channel(sba->mchans[i]);
+
+	return 0;
+}
+
+static const struct of_device_id sba_of_match[] = {
+	{ .compatible = "brcm,iproc-sba", },
+	{ .compatible = "brcm,iproc-sba-v2", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sba_of_match);
+
+static struct platform_driver sba_driver = {
+	.probe = sba_probe,
+	.remove = sba_remove,
+	.driver = {
+		.name = "bcm-sba-raid",
+		.of_match_table = sba_of_match,
+	},
+};
+module_platform_driver(sba_driver);
+
+MODULE_DESCRIPTION("Broadcom SBA RAID driver");
+MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>");
+MODULE_LICENSE("GPL v2");