Merge branch 'linus' into core/generic-dma-coherent

Conflicts:

	arch/x86/Kconfig

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1375 insertions, 0 deletions

diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
new file mode 100644
index 000000000000..a4e4494663bf
--- /dev/null
+++ b/drivers/dma/mv_xor.c
@@ -0,0 +1,1375 @@
+/*
+ * offload engine driver for the Marvell XOR engine
+ * Copyright (C) 2007, 2008, Marvell International Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/async_tx.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/memory.h>
+#include <asm/plat-orion/mv_xor.h>
+#include "mv_xor.h"
+
+static void mv_xor_issue_pending(struct dma_chan *chan);
+
+#define to_mv_xor_chan(chan)		\
+	container_of(chan, struct mv_xor_chan, common)
+
+#define to_mv_xor_device(dev)		\
+	container_of(dev, struct mv_xor_device, common)
+
+#define to_mv_xor_slot(tx)		\
+	container_of(tx, struct mv_xor_desc_slot, async_tx)
+
+static void mv_desc_init(struct mv_xor_desc_slot *desc, unsigned long flags)
+{
+	struct mv_xor_desc *hw_desc = desc->hw_desc;
+
+	hw_desc->status = (1 << 31);
+	hw_desc->phy_next_desc = 0;
+	hw_desc->desc_command = (1 << 31);
+}
+
+static u32 mv_desc_get_dest_addr(struct mv_xor_desc_slot *desc)
+{
+	struct mv_xor_desc *hw_desc = desc->hw_desc;
+	return hw_desc->phy_dest_addr;
+}
+
+static u32 mv_desc_get_src_addr(struct mv_xor_desc_slot *desc,
+				int src_idx)
+{
+	struct mv_xor_desc *hw_desc = desc->hw_desc;
+	return hw_desc->phy_src_addr[src_idx];
+}
+
+
+static void mv_desc_set_byte_count(struct mv_xor_desc_slot *desc,
+				   u32 byte_count)
+{
+	struct mv_xor_desc *hw_desc = desc->hw_desc;
+	hw_desc->byte_count = byte_count;
+}
+
+static void mv_desc_set_next_desc(struct mv_xor_desc_slot *desc,
+				  u32 next_desc_addr)
+{
+	struct mv_xor_desc *hw_desc = desc->hw_desc;
+	BUG_ON(hw_desc->phy_next_desc);
+	hw_desc->phy_next_desc = next_desc_addr;
+}
+
+static void mv_desc_clear_next_desc(struct mv_xor_desc_slot *desc)
+{
+	struct mv_xor_desc *hw_desc = desc->hw_desc;
+	hw_desc->phy_next_desc = 0;
+}
+
+static void mv_desc_set_block_fill_val(struct mv_xor_desc_slot *desc, u32 val)
+{
+	desc->value = val;
+}
+
+static void mv_desc_set_dest_addr(struct mv_xor_desc_slot *desc,
+				  dma_addr_t addr)
+{
+	struct mv_xor_desc *hw_desc = desc->hw_desc;
+	hw_desc->phy_dest_addr = addr;
+}
+
+static int mv_chan_memset_slot_count(size_t len)
+{
+	return 1;
+}
+
+#define mv_chan_memcpy_slot_count(c) mv_chan_memset_slot_count(c)
+
+static void mv_desc_set_src_addr(struct mv_xor_desc_slot *desc,
+				 int index, dma_addr_t addr)
+{
+	struct mv_xor_desc *hw_desc = desc->hw_desc;
+	hw_desc->phy_src_addr[index] = addr;
+	if (desc->type == DMA_XOR)
+		hw_desc->desc_command |= (1 << index);
+}
+
+static u32 mv_chan_get_current_desc(struct mv_xor_chan *chan)
+{
+	return __raw_readl(XOR_CURR_DESC(chan));
+}
+
+static void mv_chan_set_next_descriptor(struct mv_xor_chan *chan,
+					u32 next_desc_addr)
+{
+	__raw_writel(next_desc_addr, XOR_NEXT_DESC(chan));
+}
+
+static void mv_chan_set_dest_pointer(struct mv_xor_chan *chan, u32 desc_addr)
+{
+	__raw_writel(desc_addr, XOR_DEST_POINTER(chan));
+}
+
+static void mv_chan_set_block_size(struct mv_xor_chan *chan, u32 block_size)
+{
+	__raw_writel(block_size, XOR_BLOCK_SIZE(chan));
+}
+
+static void mv_chan_set_value(struct mv_xor_chan *chan, u32 value)
+{
+	__raw_writel(value, XOR_INIT_VALUE_LOW(chan));
+	__raw_writel(value, XOR_INIT_VALUE_HIGH(chan));
+}
+
+static void mv_chan_unmask_interrupts(struct mv_xor_chan *chan)
+{
+	u32 val = __raw_readl(XOR_INTR_MASK(chan));
+	val |= XOR_INTR_MASK_VALUE << (chan->idx * 16);
+	__raw_writel(val, XOR_INTR_MASK(chan));
+}
+
+static u32 mv_chan_get_intr_cause(struct mv_xor_chan *chan)
+{
+	u32 intr_cause = __raw_readl(XOR_INTR_CAUSE(chan));
+	intr_cause = (intr_cause >> (chan->idx * 16)) & 0xFFFF;
+	return intr_cause;
+}
+
+static int mv_is_err_intr(u32 intr_cause)
+{
+	if (intr_cause & ((1<<4)|(1<<5)|(1<<6)|(1<<7)|(1<<8)|(1<<9)))
+		return 1;
+
+	return 0;
+}
+
+static void mv_xor_device_clear_eoc_cause(struct mv_xor_chan *chan)
+{
+	u32 val = (1 << (1 + (chan->idx * 16)));
+	dev_dbg(chan->device->common.dev, "%s, val 0x%08x\n", __func__, val);
+	__raw_writel(val, XOR_INTR_CAUSE(chan));
+}
+
+static void mv_xor_device_clear_err_status(struct mv_xor_chan *chan)
+{
+	u32 val = 0xFFFF0000 >> (chan->idx * 16);
+	__raw_writel(val, XOR_INTR_CAUSE(chan));
+}
+
+static int mv_can_chain(struct mv_xor_desc_slot *desc)
+{
+	struct mv_xor_desc_slot *chain_old_tail = list_entry(
+		desc->chain_node.prev, struct mv_xor_desc_slot, chain_node);
+
+	if (chain_old_tail->type != desc->type)
+		return 0;
+	if (desc->type == DMA_MEMSET)
+		return 0;
+
+	return 1;
+}
+
+static void mv_set_mode(struct mv_xor_chan *chan,
+			       enum dma_transaction_type type)
+{
+	u32 op_mode;
+	u32 config = __raw_readl(XOR_CONFIG(chan));
+
+	switch (type) {
+	case DMA_XOR:
+		op_mode = XOR_OPERATION_MODE_XOR;
+		break;
+	case DMA_MEMCPY:
+		op_mode = XOR_OPERATION_MODE_MEMCPY;
+		break;
+	case DMA_MEMSET:
+		op_mode = XOR_OPERATION_MODE_MEMSET;
+		break;
+	default:
+		dev_printk(KERN_ERR, chan->device->common.dev,
+			   "error: unsupported operation %d.\n",
+			   type);
+		BUG();
+		return;
+	}
+
+	config &= ~0x7;
+	config |= op_mode;
+	__raw_writel(config, XOR_CONFIG(chan));
+	chan->current_type = type;
+}
+
+static void mv_chan_activate(struct mv_xor_chan *chan)
+{
+	u32 activation;
+
+	dev_dbg(chan->device->common.dev, " activate chan.\n");
+	activation = __raw_readl(XOR_ACTIVATION(chan));
+	activation |= 0x1;
+	__raw_writel(activation, XOR_ACTIVATION(chan));
+}
+
+static char mv_chan_is_busy(struct mv_xor_chan *chan)
+{
+	u32 state = __raw_readl(XOR_ACTIVATION(chan));
+
+	state = (state >> 4) & 0x3;
+
+	return (state == 1) ? 1 : 0;
+}
+
+static int mv_chan_xor_slot_count(size_t len, int src_cnt)
+{
+	return 1;
+}
+
+/**
+ * mv_xor_free_slots - flags descriptor slots for reuse
+ * @slot: Slot to free
+ * Caller must hold &mv_chan->lock while calling this function
+ */
+static void mv_xor_free_slots(struct mv_xor_chan *mv_chan,
+			      struct mv_xor_desc_slot *slot)
+{
+	dev_dbg(mv_chan->device->common.dev, "%s %d slot %p\n",
+		__func__, __LINE__, slot);
+
+	slot->slots_per_op = 0;
+
+}
+
+/*
+ * mv_xor_start_new_chain - program the engine to operate on new chain headed by
+ * sw_desc
+ * Caller must hold &mv_chan->lock while calling this function
+ */
+static void mv_xor_start_new_chain(struct mv_xor_chan *mv_chan,
+				   struct mv_xor_desc_slot *sw_desc)
+{
+	dev_dbg(mv_chan->device->common.dev, "%s %d: sw_desc %p\n",
+		__func__, __LINE__, sw_desc);
+	if (sw_desc->type != mv_chan->current_type)
+		mv_set_mode(mv_chan, sw_desc->type);
+
+	if (sw_desc->type == DMA_MEMSET) {
+		/* for memset requests we need to program the engine, no
+		 * descriptors used.
+		 */
+		struct mv_xor_desc *hw_desc = sw_desc->hw_desc;
+		mv_chan_set_dest_pointer(mv_chan, hw_desc->phy_dest_addr);
+		mv_chan_set_block_size(mv_chan, sw_desc->unmap_len);
+		mv_chan_set_value(mv_chan, sw_desc->value);
+	} else {
+		/* set the hardware chain */
+		mv_chan_set_next_descriptor(mv_chan, sw_desc->async_tx.phys);
+	}
+	mv_chan->pending += sw_desc->slot_cnt;
+	mv_xor_issue_pending(&mv_chan->common);
+}
+
+static dma_cookie_t
+mv_xor_run_tx_complete_actions(struct mv_xor_desc_slot *desc,
+	struct mv_xor_chan *mv_chan, dma_cookie_t cookie)
+{
+	BUG_ON(desc->async_tx.cookie < 0);
+
+	if (desc->async_tx.cookie > 0) {
+		cookie = desc->async_tx.cookie;
+
+		/* call the callback (must not sleep or submit new
+		 * operations to this channel)
+		 */
+		if (desc->async_tx.callback)
+			desc->async_tx.callback(
+				desc->async_tx.callback_param);
+
+		/* unmap dma addresses
+		 * (unmap_single vs unmap_page?)
+		 */
+		if (desc->group_head && desc->unmap_len) {
+			struct mv_xor_desc_slot *unmap = desc->group_head;
+			struct device *dev =
+				&mv_chan->device->pdev->dev;
+			u32 len = unmap->unmap_len;
+			enum dma_ctrl_flags flags = desc->async_tx.flags;
+			u32 src_cnt;
+			dma_addr_t addr;
+
+			if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+				addr = mv_desc_get_dest_addr(unmap);
+				dma_unmap_page(dev, addr, len, DMA_FROM_DEVICE);
+			}
+
+			if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+				src_cnt = unmap->unmap_src_cnt;
+				while (src_cnt--) {
+					addr = mv_desc_get_src_addr(unmap,
+								    src_cnt);
+					dma_unmap_page(dev, addr, len,
+						       DMA_TO_DEVICE);
+				}
+			}
+			desc->group_head = NULL;
+		}
+	}
+
+	/* run dependent operations */
+	async_tx_run_dependencies(&desc->async_tx);
+
+	return cookie;
+}
+
+static int
+mv_xor_clean_completed_slots(struct mv_xor_chan *mv_chan)
+{
+	struct mv_xor_desc_slot *iter, *_iter;
+
+	dev_dbg(mv_chan->device->common.dev, "%s %d\n", __func__, __LINE__);
+	list_for_each_entry_safe(iter, _iter, &mv_chan->completed_slots,
+				 completed_node) {
+
+		if (async_tx_test_ack(&iter->async_tx)) {
+			list_del(&iter->completed_node);
+			mv_xor_free_slots(mv_chan, iter);
+		}
+	}
+	return 0;
+}
+
+static int
+mv_xor_clean_slot(struct mv_xor_desc_slot *desc,
+	struct mv_xor_chan *mv_chan)
+{
+	dev_dbg(mv_chan->device->common.dev, "%s %d: desc %p flags %d\n",
+		__func__, __LINE__, desc, desc->async_tx.flags);
+	list_del(&desc->chain_node);
+	/* the client is allowed to attach dependent operations
+	 * until 'ack' is set
+	 */
+	if (!async_tx_test_ack(&desc->async_tx)) {
+		/* move this slot to the completed_slots */
+		list_add_tail(&desc->completed_node, &mv_chan->completed_slots);
+		return 0;
+	}
+
+	mv_xor_free_slots(mv_chan, desc);
+	return 0;
+}
+
+static void __mv_xor_slot_cleanup(struct mv_xor_chan *mv_chan)
+{
+	struct mv_xor_desc_slot *iter, *_iter;
+	dma_cookie_t cookie = 0;
+	int busy = mv_chan_is_busy(mv_chan);
+	u32 current_desc = mv_chan_get_current_desc(mv_chan);
+	int seen_current = 0;
+
+	dev_dbg(mv_chan->device->common.dev, "%s %d\n", __func__, __LINE__);
+	dev_dbg(mv_chan->device->common.dev, "current_desc %x\n", current_desc);
+	mv_xor_clean_completed_slots(mv_chan);
+
+	/* free completed slots from the chain starting with
+	 * the oldest descriptor
+	 */
+
+	list_for_each_entry_safe(iter, _iter, &mv_chan->chain,
+					chain_node) {
+		prefetch(_iter);
+		prefetch(&_iter->async_tx);
+
+		/* do not advance past the current descriptor loaded into the
+		 * hardware channel, subsequent descriptors are either in
+		 * process or have not been submitted
+		 */
+		if (seen_current)
+			break;
+
+		/* stop the search if we reach the current descriptor and the
+		 * channel is busy
+		 */
+		if (iter->async_tx.phys == current_desc) {
+			seen_current = 1;
+			if (busy)
+				break;
+		}
+
+		cookie = mv_xor_run_tx_complete_actions(iter, mv_chan, cookie);
+
+		if (mv_xor_clean_slot(iter, mv_chan))
+			break;
+	}
+
+	if ((busy == 0) && !list_empty(&mv_chan->chain)) {
+		struct mv_xor_desc_slot *chain_head;
+		chain_head = list_entry(mv_chan->chain.next,
+					struct mv_xor_desc_slot,
+					chain_node);
+
+		mv_xor_start_new_chain(mv_chan, chain_head);
+	}
+
+	if (cookie > 0)
+		mv_chan->completed_cookie = cookie;
+}
+
+static void
+mv_xor_slot_cleanup(struct mv_xor_chan *mv_chan)
+{
+	spin_lock_bh(&mv_chan->lock);
+	__mv_xor_slot_cleanup(mv_chan);
+	spin_unlock_bh(&mv_chan->lock);
+}
+
+static void mv_xor_tasklet(unsigned long data)
+{
+	struct mv_xor_chan *chan = (struct mv_xor_chan *) data;
+	__mv_xor_slot_cleanup(chan);
+}
+
+static struct mv_xor_desc_slot *
+mv_xor_alloc_slots(struct mv_xor_chan *mv_chan, int num_slots,
+		    int slots_per_op)
+{
+	struct mv_xor_desc_slot *iter, *_iter, *alloc_start = NULL;
+	LIST_HEAD(chain);
+	int slots_found, retry = 0;
+
+	/* start search from the last allocated descrtiptor
+	 * if a contiguous allocation can not be found start searching
+	 * from the beginning of the list
+	 */
+retry:
+	slots_found = 0;
+	if (retry == 0)
+		iter = mv_chan->last_used;
+	else
+		iter = list_entry(&mv_chan->all_slots,
+			struct mv_xor_desc_slot,
+			slot_node);
+
+	list_for_each_entry_safe_continue(
+		iter, _iter, &mv_chan->all_slots, slot_node) {
+		prefetch(_iter);
+		prefetch(&_iter->async_tx);
+		if (iter->slots_per_op) {
+			/* give up after finding the first busy slot
+			 * on the second pass through the list
+			 */
+			if (retry)
+				break;
+
+			slots_found = 0;
+			continue;
+		}
+
+		/* start the allocation if the slot is correctly aligned */
+		if (!slots_found++)
+			alloc_start = iter;
+
+		if (slots_found == num_slots) {
+			struct mv_xor_desc_slot *alloc_tail = NULL;
+			struct mv_xor_desc_slot *last_used = NULL;
+			iter = alloc_start;
+			while (num_slots) {
+				int i;
+
+				/* pre-ack all but the last descriptor */
+				async_tx_ack(&iter->async_tx);
+
+				list_add_tail(&iter->chain_node, &chain);
+				alloc_tail = iter;
+				iter->async_tx.cookie = 0;
+				iter->slot_cnt = num_slots;
+				iter->xor_check_result = NULL;
+				for (i = 0; i < slots_per_op; i++) {
+					iter->slots_per_op = slots_per_op - i;
+					last_used = iter;
+					iter = list_entry(iter->slot_node.next,
+						struct mv_xor_desc_slot,
+						slot_node);
+				}
+				num_slots -= slots_per_op;
+			}
+			alloc_tail->group_head = alloc_start;
+			alloc_tail->async_tx.cookie = -EBUSY;
+			list_splice(&chain, &alloc_tail->async_tx.tx_list);
+			mv_chan->last_used = last_used;
+			mv_desc_clear_next_desc(alloc_start);
+			mv_desc_clear_next_desc(alloc_tail);
+			return alloc_tail;
+		}
+	}
+	if (!retry++)
+		goto retry;
+
+	/* try to free some slots if the allocation fails */
+	tasklet_schedule(&mv_chan->irq_tasklet);
+
+	return NULL;
+}
+
+static dma_cookie_t
+mv_desc_assign_cookie(struct mv_xor_chan *mv_chan,
+		      struct mv_xor_desc_slot *desc)
+{
+	dma_cookie_t cookie = mv_chan->common.cookie;
+
+	if (++cookie < 0)
+		cookie = 1;
+	mv_chan->common.cookie = desc->async_tx.cookie = cookie;
+	return cookie;
+}
+
+/************************ DMA engine API functions ****************************/
+static dma_cookie_t
+mv_xor_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct mv_xor_desc_slot *sw_desc = to_mv_xor_slot(tx);
+	struct mv_xor_chan *mv_chan = to_mv_xor_chan(tx->chan);
+	struct mv_xor_desc_slot *grp_start, *old_chain_tail;
+	dma_cookie_t cookie;
+	int new_hw_chain = 1;
+
+	dev_dbg(mv_chan->device->common.dev,
+		"%s sw_desc %p: async_tx %p\n",
+		__func__, sw_desc, &sw_desc->async_tx);
+
+	grp_start = sw_desc->group_head;
+
+	spin_lock_bh(&mv_chan->lock);
+	cookie = mv_desc_assign_cookie(mv_chan, sw_desc);
+
+	if (list_empty(&mv_chan->chain))
+		list_splice_init(&sw_desc->async_tx.tx_list, &mv_chan->chain);
+	else {
+		new_hw_chain = 0;
+
+		old_chain_tail = list_entry(mv_chan->chain.prev,
+					    struct mv_xor_desc_slot,
+					    chain_node);
+		list_splice_init(&grp_start->async_tx.tx_list,
+				 &old_chain_tail->chain_node);
+
+		if (!mv_can_chain(grp_start))
+			goto submit_done;
+
+		dev_dbg(mv_chan->device->common.dev, "Append to last desc %x\n",
+			old_chain_tail->async_tx.phys);
+
+		/* fix up the hardware chain */
+		mv_desc_set_next_desc(old_chain_tail, grp_start->async_tx.phys);
+
+		/* if the channel is not busy */
+		if (!mv_chan_is_busy(mv_chan)) {
+			u32 current_desc = mv_chan_get_current_desc(mv_chan);
+			/*
+			 * and the curren desc is the end of the chain before
+			 * the append, then we need to start the channel
+			 */
+			if (current_desc == old_chain_tail->async_tx.phys)
+				new_hw_chain = 1;
+		}
+	}
+
+	if (new_hw_chain)
+		mv_xor_start_new_chain(mv_chan, grp_start);
+
+submit_done:
+	spin_unlock_bh(&mv_chan->lock);
+
+	return cookie;
+}
+
+/* returns the number of allocated descriptors */
+static int mv_xor_alloc_chan_resources(struct dma_chan *chan,
+				       struct dma_client *client)
+{
+	char *hw_desc;
+	int idx;
+	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+	struct mv_xor_desc_slot *slot = NULL;
+	struct mv_xor_platform_data *plat_data =
+		mv_chan->device->pdev->dev.platform_data;
+	int num_descs_in_pool = plat_data->pool_size/MV_XOR_SLOT_SIZE;
+
+	/* Allocate descriptor slots */
+	idx = mv_chan->slots_allocated;
+	while (idx < num_descs_in_pool) {
+		slot = kzalloc(sizeof(*slot), GFP_KERNEL);
+		if (!slot) {
+			printk(KERN_INFO "MV XOR Channel only initialized"
+				" %d descriptor slots", idx);
+			break;
+		}
+		hw_desc = (char *) mv_chan->device->dma_desc_pool_virt;
+		slot->hw_desc = (void *) &hw_desc[idx * MV_XOR_SLOT_SIZE];
+
+		dma_async_tx_descriptor_init(&slot->async_tx, chan);
+		slot->async_tx.tx_submit = mv_xor_tx_submit;
+		INIT_LIST_HEAD(&slot->chain_node);
+		INIT_LIST_HEAD(&slot->slot_node);
+		INIT_LIST_HEAD(&slot->async_tx.tx_list);
+		hw_desc = (char *) mv_chan->device->dma_desc_pool;
+		slot->async_tx.phys =
+			(dma_addr_t) &hw_desc[idx * MV_XOR_SLOT_SIZE];
+		slot->idx = idx++;
+
+		spin_lock_bh(&mv_chan->lock);
+		mv_chan->slots_allocated = idx;
+		list_add_tail(&slot->slot_node, &mv_chan->all_slots);
+		spin_unlock_bh(&mv_chan->lock);
+	}
+
+	if (mv_chan->slots_allocated && !mv_chan->last_used)
+		mv_chan->last_used = list_entry(mv_chan->all_slots.next,
+					struct mv_xor_desc_slot,
+					slot_node);
+
+	dev_dbg(mv_chan->device->common.dev,
+		"allocated %d descriptor slots last_used: %p\n",
+		mv_chan->slots_allocated, mv_chan->last_used);
+
+	return mv_chan->slots_allocated ? : -ENOMEM;
+}
+
+static struct dma_async_tx_descriptor *
+mv_xor_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+		size_t len, unsigned long flags)
+{
+	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+	struct mv_xor_desc_slot *sw_desc, *grp_start;
+	int slot_cnt;
+
+	dev_dbg(mv_chan->device->common.dev,
+		"%s dest: %x src %x len: %u flags: %ld\n",
+		__func__, dest, src, len, flags);
+	if (unlikely(len < MV_XOR_MIN_BYTE_COUNT))
+		return NULL;
+
+	BUG_ON(unlikely(len > MV_XOR_MAX_BYTE_COUNT));
+
+	spin_lock_bh(&mv_chan->lock);
+	slot_cnt = mv_chan_memcpy_slot_count(len);
+	sw_desc = mv_xor_alloc_slots(mv_chan, slot_cnt, 1);
+	if (sw_desc) {
+		sw_desc->type = DMA_MEMCPY;
+		sw_desc->async_tx.flags = flags;
+		grp_start = sw_desc->group_head;
+		mv_desc_init(grp_start, flags);
+		mv_desc_set_byte_count(grp_start, len);
+		mv_desc_set_dest_addr(sw_desc->group_head, dest);
+		mv_desc_set_src_addr(grp_start, 0, src);
+		sw_desc->unmap_src_cnt = 1;
+		sw_desc->unmap_len = len;
+	}
+	spin_unlock_bh(&mv_chan->lock);
+
+	dev_dbg(mv_chan->device->common.dev,
+		"%s sw_desc %p async_tx %p\n",
+		__func__, sw_desc, sw_desc ? &sw_desc->async_tx : 0);
+
+	return sw_desc ? &sw_desc->async_tx : NULL;
+}
+
+static struct dma_async_tx_descriptor *
+mv_xor_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
+		       size_t len, unsigned long flags)
+{
+	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+	struct mv_xor_desc_slot *sw_desc, *grp_start;
+	int slot_cnt;
+
+	dev_dbg(mv_chan->device->common.dev,
+		"%s dest: %x len: %u flags: %ld\n",
+		__func__, dest, len, flags);
+	if (unlikely(len < MV_XOR_MIN_BYTE_COUNT))
+		return NULL;
+
+	BUG_ON(unlikely(len > MV_XOR_MAX_BYTE_COUNT));
+
+	spin_lock_bh(&mv_chan->lock);
+	slot_cnt = mv_chan_memset_slot_count(len);
+	sw_desc = mv_xor_alloc_slots(mv_chan, slot_cnt, 1);
+	if (sw_desc) {
+		sw_desc->type = DMA_MEMSET;
+		sw_desc->async_tx.flags = flags;
+		grp_start = sw_desc->group_head;
+		mv_desc_init(grp_start, flags);
+		mv_desc_set_byte_count(grp_start, len);
+		mv_desc_set_dest_addr(sw_desc->group_head, dest);
+		mv_desc_set_block_fill_val(grp_start, value);
+		sw_desc->unmap_src_cnt = 1;
+		sw_desc->unmap_len = len;
+	}
+	spin_unlock_bh(&mv_chan->lock);
+	dev_dbg(mv_chan->device->common.dev,
+		"%s sw_desc %p async_tx %p \n",
+		__func__, sw_desc, &sw_desc->async_tx);
+	return sw_desc ? &sw_desc->async_tx : NULL;
+}
+
+static struct dma_async_tx_descriptor *
+mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
+		    unsigned int src_cnt, size_t len, unsigned long flags)
+{
+	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+	struct mv_xor_desc_slot *sw_desc, *grp_start;
+	int slot_cnt;
+
+	if (unlikely(len < MV_XOR_MIN_BYTE_COUNT))
+		return NULL;
+
+	BUG_ON(unlikely(len > MV_XOR_MAX_BYTE_COUNT));
+
+	dev_dbg(mv_chan->device->common.dev,
+		"%s src_cnt: %d len: dest %x %u flags: %ld\n",
+		__func__, src_cnt, len, dest, flags);
+
+	spin_lock_bh(&mv_chan->lock);
+	slot_cnt = mv_chan_xor_slot_count(len, src_cnt);
+	sw_desc = mv_xor_alloc_slots(mv_chan, slot_cnt, 1);
+	if (sw_desc) {
+		sw_desc->type = DMA_XOR;
+		sw_desc->async_tx.flags = flags;
+		grp_start = sw_desc->group_head;
+		mv_desc_init(grp_start, flags);
+		/* the byte count field is the same as in memcpy desc*/
+		mv_desc_set_byte_count(grp_start, len);
+		mv_desc_set_dest_addr(sw_desc->group_head, dest);
+		sw_desc->unmap_src_cnt = src_cnt;
+		sw_desc->unmap_len = len;
+		while (src_cnt--)
+			mv_desc_set_src_addr(grp_start, src_cnt, src[src_cnt]);
+	}
+	spin_unlock_bh(&mv_chan->lock);
+	dev_dbg(mv_chan->device->common.dev,
+		"%s sw_desc %p async_tx %p \n",
+		__func__, sw_desc, &sw_desc->async_tx);
+	return sw_desc ? &sw_desc->async_tx : NULL;
+}
+
+static void mv_xor_free_chan_resources(struct dma_chan *chan)
+{
+	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+	struct mv_xor_desc_slot *iter, *_iter;
+	int in_use_descs = 0;
+
+	mv_xor_slot_cleanup(mv_chan);
+
+	spin_lock_bh(&mv_chan->lock);
+	list_for_each_entry_safe(iter, _iter, &mv_chan->chain,
+					chain_node) {
+		in_use_descs++;
+		list_del(&iter->chain_node);
+	}
+	list_for_each_entry_safe(iter, _iter, &mv_chan->completed_slots,
+				 completed_node) {
+		in_use_descs++;
+		list_del(&iter->completed_node);
+	}
+	list_for_each_entry_safe_reverse(
+		iter, _iter, &mv_chan->all_slots, slot_node) {
+		list_del(&iter->slot_node);
+		kfree(iter);
+		mv_chan->slots_allocated--;
+	}
+	mv_chan->last_used = NULL;
+
+	dev_dbg(mv_chan->device->common.dev, "%s slots_allocated %d\n",
+		__func__, mv_chan->slots_allocated);
+	spin_unlock_bh(&mv_chan->lock);
+
+	if (in_use_descs)
+		dev_err(mv_chan->device->common.dev,
+			"freeing %d in use descriptors!\n", in_use_descs);
+}
+
+/**
+ * mv_xor_is_complete - poll the status of an XOR transaction
+ * @chan: XOR channel handle
+ * @cookie: XOR transaction identifier
+ */
+static enum dma_status mv_xor_is_complete(struct dma_chan *chan,
+					  dma_cookie_t cookie,
+					  dma_cookie_t *done,
+					  dma_cookie_t *used)
+{
+	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+	dma_cookie_t last_used;
+	dma_cookie_t last_complete;
+	enum dma_status ret;
+
+	last_used = chan->cookie;
+	last_complete = mv_chan->completed_cookie;
+	mv_chan->is_complete_cookie = cookie;
+	if (done)
+		*done = last_complete;
+	if (used)
+		*used = last_used;
+
+	ret = dma_async_is_complete(cookie, last_complete, last_used);
+	if (ret == DMA_SUCCESS) {
+		mv_xor_clean_completed_slots(mv_chan);
+		return ret;
+	}
+	mv_xor_slot_cleanup(mv_chan);
+
+	last_used = chan->cookie;
+	last_complete = mv_chan->completed_cookie;
+
+	if (done)
+		*done = last_complete;
+	if (used)
+		*used = last_used;
+
+	return dma_async_is_complete(cookie, last_complete, last_used);
+}
+
+static void mv_dump_xor_regs(struct mv_xor_chan *chan)
+{
+	u32 val;
+
+	val = __raw_readl(XOR_CONFIG(chan));
+	dev_printk(KERN_ERR, chan->device->common.dev,
+		   "config       0x%08x.\n", val);
+
+	val = __raw_readl(XOR_ACTIVATION(chan));
+	dev_printk(KERN_ERR, chan->device->common.dev,
+		   "activation   0x%08x.\n", val);
+
+	val = __raw_readl(XOR_INTR_CAUSE(chan));
+	dev_printk(KERN_ERR, chan->device->common.dev,
+		   "intr cause   0x%08x.\n", val);
+
+	val = __raw_readl(XOR_INTR_MASK(chan));
+	dev_printk(KERN_ERR, chan->device->common.dev,
+		   "intr mask    0x%08x.\n", val);
+
+	val = __raw_readl(XOR_ERROR_CAUSE(chan));
+	dev_printk(KERN_ERR, chan->device->common.dev,
+		   "error cause  0x%08x.\n", val);
+
+	val = __raw_readl(XOR_ERROR_ADDR(chan));
+	dev_printk(KERN_ERR, chan->device->common.dev,
+		   "error addr   0x%08x.\n", val);
+}
+
+static void mv_xor_err_interrupt_handler(struct mv_xor_chan *chan,
+					 u32 intr_cause)
+{
+	if (intr_cause & (1 << 4)) {
+	     dev_dbg(chan->device->common.dev,
+		     "ignore this error\n");
+	     return;
+	}
+
+	dev_printk(KERN_ERR, chan->device->common.dev,
+		   "error on chan %d. intr cause 0x%08x.\n",
+		   chan->idx, intr_cause);
+
+	mv_dump_xor_regs(chan);
+	BUG();
+}
+
+static irqreturn_t mv_xor_interrupt_handler(int irq, void *data)
+{
+	struct mv_xor_chan *chan = data;
+	u32 intr_cause = mv_chan_get_intr_cause(chan);
+
+	dev_dbg(chan->device->common.dev, "intr cause %x\n", intr_cause);
+
+	if (mv_is_err_intr(intr_cause))
+		mv_xor_err_interrupt_handler(chan, intr_cause);
+
+	tasklet_schedule(&chan->irq_tasklet);
+
+	mv_xor_device_clear_eoc_cause(chan);
+
+	return IRQ_HANDLED;
+}
+
+static void mv_xor_issue_pending(struct dma_chan *chan)
+{
+	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+
+	if (mv_chan->pending >= MV_XOR_THRESHOLD) {
+		mv_chan->pending = 0;
+		mv_chan_activate(mv_chan);
+	}
+}
+
+/*
+ * Perform a transaction to verify the HW works.
+ */
+#define MV_XOR_TEST_SIZE 2000
+
+static int __devinit mv_xor_memcpy_self_test(struct mv_xor_device *device)
+{
+	int i;
+	void *src, *dest;
+	dma_addr_t src_dma, dest_dma;
+	struct dma_chan *dma_chan;
+	dma_cookie_t cookie;
+	struct dma_async_tx_descriptor *tx;
+	int err = 0;
+	struct mv_xor_chan *mv_chan;
+
+	src = kmalloc(sizeof(u8) * MV_XOR_TEST_SIZE, GFP_KERNEL);
+	if (!src)
+		return -ENOMEM;
+
+	dest = kzalloc(sizeof(u8) * MV_XOR_TEST_SIZE, GFP_KERNEL);
+	if (!dest) {
+		kfree(src);
+		return -ENOMEM;
+	}
+
+	/* Fill in src buffer */
+	for (i = 0; i < MV_XOR_TEST_SIZE; i++)
+		((u8 *) src)[i] = (u8)i;
+
+	/* Start copy, using first DMA channel */
+	dma_chan = container_of(device->common.channels.next,
+				struct dma_chan,
+				device_node);
+	if (mv_xor_alloc_chan_resources(dma_chan, NULL) < 1) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	dest_dma = dma_map_single(dma_chan->device->dev, dest,
+				  MV_XOR_TEST_SIZE, DMA_FROM_DEVICE);
+
+	src_dma = dma_map_single(dma_chan->device->dev, src,
+				 MV_XOR_TEST_SIZE, DMA_TO_DEVICE);
+
+	tx = mv_xor_prep_dma_memcpy(dma_chan, dest_dma, src_dma,
+				    MV_XOR_TEST_SIZE, 0);
+	cookie = mv_xor_tx_submit(tx);
+	mv_xor_issue_pending(dma_chan);
+	async_tx_ack(tx);
+	msleep(1);
+
+	if (mv_xor_is_complete(dma_chan, cookie, NULL, NULL) !=
+	    DMA_SUCCESS) {
+		dev_printk(KERN_ERR, dma_chan->device->dev,
+			   "Self-test copy timed out, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+
+	mv_chan = to_mv_xor_chan(dma_chan);
+	dma_sync_single_for_cpu(&mv_chan->device->pdev->dev, dest_dma,
+				MV_XOR_TEST_SIZE, DMA_FROM_DEVICE);
+	if (memcmp(src, dest, MV_XOR_TEST_SIZE)) {
+		dev_printk(KERN_ERR, dma_chan->device->dev,
+			   "Self-test copy failed compare, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+
+free_resources:
+	mv_xor_free_chan_resources(dma_chan);
+out:
+	kfree(src);
+	kfree(dest);
+	return err;
+}
+
+#define MV_XOR_NUM_SRC_TEST 4 /* must be <= 15 */
+static int __devinit
+mv_xor_xor_self_test(struct mv_xor_device *device)
+{
+	int i, src_idx;
+	struct page *dest;
+	struct page *xor_srcs[MV_XOR_NUM_SRC_TEST];
+	dma_addr_t dma_srcs[MV_XOR_NUM_SRC_TEST];
+	dma_addr_t dest_dma;
+	struct dma_async_tx_descriptor *tx;
+	struct dma_chan *dma_chan;
+	dma_cookie_t cookie;
+	u8 cmp_byte = 0;
+	u32 cmp_word;
+	int err = 0;
+	struct mv_xor_chan *mv_chan;
+
+	for (src_idx = 0; src_idx < MV_XOR_NUM_SRC_TEST; src_idx++) {
+		xor_srcs[src_idx] = alloc_page(GFP_KERNEL);
+		if (!xor_srcs[src_idx])
+			while (src_idx--) {
+				__free_page(xor_srcs[src_idx]);
+				return -ENOMEM;
+			}
+	}
+
+	dest = alloc_page(GFP_KERNEL);
+	if (!dest)
+		while (src_idx--) {
+			__free_page(xor_srcs[src_idx]);
+			return -ENOMEM;
+		}
+
+	/* Fill in src buffers */
+	for (src_idx = 0; src_idx < MV_XOR_NUM_SRC_TEST; src_idx++) {
+		u8 *ptr = page_address(xor_srcs[src_idx]);
+		for (i = 0; i < PAGE_SIZE; i++)
+			ptr[i] = (1 << src_idx);
+	}
+
+	for (src_idx = 0; src_idx < MV_XOR_NUM_SRC_TEST; src_idx++)
+		cmp_byte ^= (u8) (1 << src_idx);
+
+	cmp_word = (cmp_byte << 24) | (cmp_byte << 16) |
+		(cmp_byte << 8) | cmp_byte;
+
+	memset(page_address(dest), 0, PAGE_SIZE);
+
+	dma_chan = container_of(device->common.channels.next,
+				struct dma_chan,
+				device_node);
+	if (mv_xor_alloc_chan_resources(dma_chan, NULL) < 1) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	/* test xor */
+	dest_dma = dma_map_page(dma_chan->device->dev, dest, 0, PAGE_SIZE,
+				DMA_FROM_DEVICE);
+
+	for (i = 0; i < MV_XOR_NUM_SRC_TEST; i++)
+		dma_srcs[i] = dma_map_page(dma_chan->device->dev, xor_srcs[i],
+					   0, PAGE_SIZE, DMA_TO_DEVICE);
+
+	tx = mv_xor_prep_dma_xor(dma_chan, dest_dma, dma_srcs,
+				 MV_XOR_NUM_SRC_TEST, PAGE_SIZE, 0);
+
+	cookie = mv_xor_tx_submit(tx);
+	mv_xor_issue_pending(dma_chan);
+	async_tx_ack(tx);
+	msleep(8);
+
+	if (mv_xor_is_complete(dma_chan, cookie, NULL, NULL) !=
+	    DMA_SUCCESS) {
+		dev_printk(KERN_ERR, dma_chan->device->dev,
+			   "Self-test xor timed out, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+
+	mv_chan = to_mv_xor_chan(dma_chan);
+	dma_sync_single_for_cpu(&mv_chan->device->pdev->dev, dest_dma,
+				PAGE_SIZE, DMA_FROM_DEVICE);
+	for (i = 0; i < (PAGE_SIZE / sizeof(u32)); i++) {
+		u32 *ptr = page_address(dest);
+		if (ptr[i] != cmp_word) {
+			dev_printk(KERN_ERR, dma_chan->device->dev,
+				   "Self-test xor failed compare, disabling."
+				   " index %d, data %x, expected %x\n", i,
+				   ptr[i], cmp_word);
+			err = -ENODEV;
+			goto free_resources;
+		}
+	}
+
+free_resources:
+	mv_xor_free_chan_resources(dma_chan);
+out:
+	src_idx = MV_XOR_NUM_SRC_TEST;
+	while (src_idx--)
+		__free_page(xor_srcs[src_idx]);
+	__free_page(dest);
+	return err;
+}
+
+static int __devexit mv_xor_remove(struct platform_device *dev)
+{
+	struct mv_xor_device *device = platform_get_drvdata(dev);
+	struct dma_chan *chan, *_chan;
+	struct mv_xor_chan *mv_chan;
+	struct mv_xor_platform_data *plat_data = dev->dev.platform_data;
+
+	dma_async_device_unregister(&device->common);
+
+	dma_free_coherent(&dev->dev, plat_data->pool_size,
+			device->dma_desc_pool_virt, device->dma_desc_pool);
+
+	list_for_each_entry_safe(chan, _chan, &device->common.channels,
+				device_node) {
+		mv_chan = to_mv_xor_chan(chan);
+		list_del(&chan->device_node);
+	}
+
+	return 0;
+}
+
+static int __devinit mv_xor_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	int irq;
+	struct mv_xor_device *adev;
+	struct mv_xor_chan *mv_chan;
+	struct dma_device *dma_dev;
+	struct mv_xor_platform_data *plat_data = pdev->dev.platform_data;
+
+
+	adev = devm_kzalloc(&pdev->dev, sizeof(*adev), GFP_KERNEL);
+	if (!adev)
+		return -ENOMEM;
+
+	dma_dev = &adev->common;
+
+	/* allocate coherent memory for hardware descriptors
+	 * note: writecombine gives slightly better performance, but
+	 * requires that we explicitly flush the writes
+	 */
+	adev->dma_desc_pool_virt = dma_alloc_writecombine(&pdev->dev,
+							  plat_data->pool_size,
+							  &adev->dma_desc_pool,
+							  GFP_KERNEL);
+	if (!adev->dma_desc_pool_virt)
+		return -ENOMEM;
+
+	adev->id = plat_data->hw_id;
+
+	/* discover transaction capabilites from the platform data */
+	dma_dev->cap_mask = plat_data->cap_mask;
+	adev->pdev = pdev;
+	platform_set_drvdata(pdev, adev);
+
+	adev->shared = platform_get_drvdata(plat_data->shared);
+
+	INIT_LIST_HEAD(&dma_dev->channels);
+
+	/* set base routines */
+	dma_dev->device_alloc_chan_resources = mv_xor_alloc_chan_resources;
+	dma_dev->device_free_chan_resources = mv_xor_free_chan_resources;
+	dma_dev->device_is_tx_complete = mv_xor_is_complete;
+	dma_dev->device_issue_pending = mv_xor_issue_pending;
+	dma_dev->dev = &pdev->dev;
+
+	/* set prep routines based on capability */
+	if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask))
+		dma_dev->device_prep_dma_memcpy = mv_xor_prep_dma_memcpy;
+	if (dma_has_cap(DMA_MEMSET, dma_dev->cap_mask))
+		dma_dev->device_prep_dma_memset = mv_xor_prep_dma_memset;
+	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
+		dma_dev->max_xor = 8;                  ;
+		dma_dev->device_prep_dma_xor = mv_xor_prep_dma_xor;
+	}
+
+	mv_chan = devm_kzalloc(&pdev->dev, sizeof(*mv_chan), GFP_KERNEL);
+	if (!mv_chan) {
+		ret = -ENOMEM;
+		goto err_free_dma;
+	}
+	mv_chan->device = adev;
+	mv_chan->idx = plat_data->hw_id;
+	mv_chan->mmr_base = adev->shared->xor_base;
+
+	if (!mv_chan->mmr_base) {
+		ret = -ENOMEM;
+		goto err_free_dma;
+	}
+	tasklet_init(&mv_chan->irq_tasklet, mv_xor_tasklet, (unsigned long)
+		     mv_chan);
+
+	/* clear errors before enabling interrupts */
+	mv_xor_device_clear_err_status(mv_chan);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = irq;
+		goto err_free_dma;
+	}
+	ret = devm_request_irq(&pdev->dev, irq,
+			       mv_xor_interrupt_handler,
+			       0, dev_name(&pdev->dev), mv_chan);
+	if (ret)
+		goto err_free_dma;
+
+	mv_chan_unmask_interrupts(mv_chan);
+
+	mv_set_mode(mv_chan, DMA_MEMCPY);
+
+	spin_lock_init(&mv_chan->lock);
+	INIT_LIST_HEAD(&mv_chan->chain);
+	INIT_LIST_HEAD(&mv_chan->completed_slots);
+	INIT_LIST_HEAD(&mv_chan->all_slots);
+	INIT_RCU_HEAD(&mv_chan->common.rcu);
+	mv_chan->common.device = dma_dev;
+
+	list_add_tail(&mv_chan->common.device_node, &dma_dev->channels);
+
+	if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {
+		ret = mv_xor_memcpy_self_test(adev);
+		dev_dbg(&pdev->dev, "memcpy self test returned %d\n", ret);
+		if (ret)
+			goto err_free_dma;
+	}
+
+	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
+		ret = mv_xor_xor_self_test(adev);
+		dev_dbg(&pdev->dev, "xor self test returned %d\n", ret);
+		if (ret)
+			goto err_free_dma;
+	}
+
+	dev_printk(KERN_INFO, &pdev->dev, "Marvell XOR: "
+	  "( %s%s%s%s)\n",
+	  dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "xor " : "",
+	  dma_has_cap(DMA_MEMSET, dma_dev->cap_mask)  ? "fill " : "",
+	  dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "cpy " : "",
+	  dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask) ? "intr " : "");
+
+	dma_async_device_register(dma_dev);
+	goto out;
+
+ err_free_dma:
+	dma_free_coherent(&adev->pdev->dev, plat_data->pool_size,
+			adev->dma_desc_pool_virt, adev->dma_desc_pool);
+ out:
+	return ret;
+}
+
+static void
+mv_xor_conf_mbus_windows(struct mv_xor_shared_private *msp,
+			 struct mbus_dram_target_info *dram)
+{
+	void __iomem *base = msp->xor_base;
+	u32 win_enable = 0;
+	int i;
+
+	for (i = 0; i < 8; i++) {
+		writel(0, base + WINDOW_BASE(i));
+		writel(0, base + WINDOW_SIZE(i));
+		if (i < 4)
+			writel(0, base + WINDOW_REMAP_HIGH(i));
+	}
+
+	for (i = 0; i < dram->num_cs; i++) {
+		struct mbus_dram_window *cs = dram->cs + i;
+
+		writel((cs->base & 0xffff0000) |
+		       (cs->mbus_attr << 8) |
+		       dram->mbus_dram_target_id, base + WINDOW_BASE(i));
+		writel((cs->size - 1) & 0xffff0000, base + WINDOW_SIZE(i));
+
+		win_enable |= (1 << i);
+		win_enable |= 3 << (16 + (2 * i));
+	}
+
+	writel(win_enable, base + WINDOW_BAR_ENABLE(0));
+	writel(win_enable, base + WINDOW_BAR_ENABLE(1));
+}
+
+static struct platform_driver mv_xor_driver = {
+	.probe		= mv_xor_probe,
+	.remove		= mv_xor_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= MV_XOR_NAME,
+	},
+};
+
+static int mv_xor_shared_probe(struct platform_device *pdev)
+{
+	struct mv_xor_platform_shared_data *msd = pdev->dev.platform_data;
+	struct mv_xor_shared_private *msp;
+	struct resource *res;
+
+	dev_printk(KERN_NOTICE, &pdev->dev, "Marvell shared XOR driver\n");
+
+	msp = devm_kzalloc(&pdev->dev, sizeof(*msp), GFP_KERNEL);
+	if (!msp)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	msp->xor_base = devm_ioremap(&pdev->dev, res->start,
+				     res->end - res->start + 1);
+	if (!msp->xor_base)
+		return -EBUSY;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res)
+		return -ENODEV;
+
+	msp->xor_high_base = devm_ioremap(&pdev->dev, res->start,
+					  res->end - res->start + 1);
+	if (!msp->xor_high_base)
+		return -EBUSY;
+
+	platform_set_drvdata(pdev, msp);
+
+	/*
+	 * (Re-)program MBUS remapping windows if we are asked to.
+	 */
+	if (msd != NULL && msd->dram != NULL)
+		mv_xor_conf_mbus_windows(msp, msd->dram);
+
+	return 0;
+}
+
+static int mv_xor_shared_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver mv_xor_shared_driver = {
+	.probe		= mv_xor_shared_probe,
+	.remove		= mv_xor_shared_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= MV_XOR_SHARED_NAME,
+	},
+};
+
+
+static int __init mv_xor_init(void)
+{
+	int rc;
+
+	rc = platform_driver_register(&mv_xor_shared_driver);
+	if (!rc) {
+		rc = platform_driver_register(&mv_xor_driver);
+		if (rc)
+			platform_driver_unregister(&mv_xor_shared_driver);
+	}
+	return rc;
+}
+module_init(mv_xor_init);
+
+/* it's currently unsafe to unload this module */
+#if 0
+static void __exit mv_xor_exit(void)
+{
+	platform_driver_unregister(&mv_xor_driver);
+	platform_driver_unregister(&mv_xor_shared_driver);
+	return;
+}
+
+module_exit(mv_xor_exit);
+#endif
+
+MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
+MODULE_DESCRIPTION("DMA engine driver for Marvell's XOR engine");
+MODULE_LICENSE("GPL");