gpl-source-mybooklive-010002-update.zipgpl-source-mybooklive-010103-update.zipgpl-source-mybooklive-010002-update.zip

1 files changed, 2433 insertions, 0 deletions

diff --git a/drivers/dma/apm82181-adma.c b/drivers/dma/apm82181-adma.c
new file mode 100644
index 00000000000..5800ca15e56
--- /dev/null
+++ b/drivers/dma/apm82181-adma.c
@@ -0,0 +1,2433 @@
+/*
+ * Copyright(c) 2010 Applied Micro Circuits Corporation(AMCC). All rights reserved.
+ *
+ * Author: Tai Tri Nguyen <ttnguyen@appliedmicro.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.
+ *
+ * The full GNU General Public License is included in this distribution in the
+ * file called COPYING.
+ */
+
+/*
+ * This driver supports the asynchrounous DMA copy and RAID engines available
+ * on the AppliedMicro APM82181 Processor.
+ * Based on the Intel Xscale(R) family of I/O Processors (IOP 32x, 33x, 134x)
+ * ADMA driver written by D.Williams.
+ */
+#define ADMA_DEBUG
+#undef ADMA_DEBUG
+
+#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/uaccess.h>
+#include <linux/of_platform.h>
+#include <linux/proc_fs.h>
+#include <asm/dcr.h>
+#include <asm/dcr-regs.h>
+#include <asm/apm82181-adma.h>
+
+#define PPC4XX_EDMA "apm82181-adma: "
+#ifdef ADMA_DEBUG
+#define DBG(string, args...) \
+        printk(PPC4XX_EDMA string ,##args)
+#define INFO DBG("<%s> -- line %d\n",__func__,__LINE__);
+#define ADMA_HEXDUMP(b, l)                                              \
+  	print_hex_dump(KERN_CONT, "", DUMP_PREFIX_OFFSET,                     \
+                 16, 1, (b), (l), false);
+#else
+#define DBG(string, args...) \
+        {if (0) printk(KERN_INFO PPC4XX_EDMA string ,##args); 0; }
+#define INFO DBG("");
+#define ADMA_HEXDUMP(b, l)                                              \
+        {if (0) print_hex_dump(KERN_CONT, "", DUMP_PREFIX_OFFSET,       \
+                 8, 1, (b), (l), false); 0;}
+#endif
+
+#define MEM_HEXDUMP(b, l)                                              \
+        print_hex_dump(KERN_CONT, "", DUMP_PREFIX_OFFSET,                     \
+                 16, 1, (b), (l), false);
+
+/* The list of channels exported by apm82181 ADMA */
+struct list_head
+ppc_adma_chan_list = LIST_HEAD_INIT(ppc_adma_chan_list);
+
+/* This flag is set when want to refetch the xor chain in the interrupt
+ * handler
+ */
+static u32 do_xor_refetch = 0;
+
+/* Pointers to last submitted to DMA0/1/2/3 and XOR CDBs */
+static apm82181_desc_t *chan_last_sub[5];
+static apm82181_desc_t *chan_first_cdb[5];
+
+/* Pointer to last linked and submitted xor CB */
+static apm82181_desc_t *xor_last_linked = NULL;
+static apm82181_desc_t *xor_last_submit = NULL;
+
+/* /proc interface is used here to verify the h/w RAID 5 capabilities
+ */
+static struct proc_dir_entry *apm82181_proot;
+
+/* These are used in enable & check routines
+ */
+static u32 apm82181_xor_verified;
+static u32 apm82181_memcpy_verified[4];
+static apm82181_ch_t *apm82181_dma_tchan[5];
+static struct completion apm82181_r5_test_comp;
+
+static inline int apm82181_chan_is_busy(apm82181_ch_t *chan);
+#if 0
+static phys_addr_t fixup_bigphys_addr(phys_addr_t addr, phys_addr_t size)
+{
+	phys_addr_t page_4gb = 0;
+	 
+	return (page_4gb | addr);
+}
+#endif
+/**
+ * apm82181_adma_device_estimate - estimate the efficiency of processing
+ *      the operation given on this channel. It's assumed that 'chan' is
+ *      capable to process 'cap' type of operation.
+ * @chan: channel to use
+ * @cap: type of transaction
+ * @src_lst: array of source pointers
+ * @src_cnt: number of source operands
+ * @src_sz: size of each source operand
+ */
+int apm82181_adma_estimate (struct dma_chan *chan,
+        enum dma_transaction_type cap, struct page **src_lst,
+        int src_cnt, size_t src_sz)
+{
+        int ef = 1;
+
+        /* channel idleness increases the priority */
+        if (likely(ef) &&
+            !apm82181_chan_is_busy(to_apm82181_adma_chan(chan)))
+                ef++;
+        else { 
+		if(chan->chan_id !=APM82181_XOR_ID)
+                        ef = -1;
+	}
+        return ef;
+}
+
+/******************************************************************************
+ * Command (Descriptor) Blocks low-level routines
+ ******************************************************************************/
+/**
+ * apm82181_desc_init_interrupt - initialize the descriptor for INTERRUPT
+ * pseudo operation
+ */
+static inline void apm82181_desc_init_interrupt (apm82181_desc_t *desc,
+							apm82181_ch_t *chan)
+{
+	xor_cb_t *p;
+		
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		BUG();
+		break;
+	case APM82181_XOR_ID:
+		p = desc->hw_desc;
+                memset (desc->hw_desc, 0, sizeof(xor_cb_t));
+                /* NOP with Command Block Complete Enable */
+                p->cbc = XOR_CBCR_CBCE_BIT;
+                break;
+	default:
+		printk(KERN_ERR "Unsupported id %d in %s\n", chan->device->id,
+				__FUNCTION__);
+		break;
+	}
+}
+
+/**
+ * apm82181_desc_init_xor - initialize the descriptor for XOR operation
+ */
+static inline void apm82181_desc_init_xor(apm82181_desc_t *desc, int src_cnt,
+                unsigned long flags)
+{
+        xor_cb_t *hw_desc = desc->hw_desc;
+
+        memset (desc->hw_desc, 0, sizeof(xor_cb_t));
+        desc->hw_next = NULL;
+        desc->src_cnt = src_cnt;
+        desc->dst_cnt = 1;
+
+        hw_desc->cbc = XOR_CBCR_TGT_BIT | src_cnt;
+        if (flags & DMA_PREP_INTERRUPT)
+                /* Enable interrupt on complete */
+                hw_desc->cbc |= XOR_CBCR_CBCE_BIT;
+}
+
+/**
+ * apm82181_desc_init_memcpy - initialize the descriptor for MEMCPY operation
+ */
+static inline void apm82181_desc_init_memcpy(apm82181_desc_t *desc,
+		unsigned long flags)
+{
+	dma_cdb_t *hw_desc = desc->hw_desc;
+
+	memset(hw_desc, 0, sizeof(dma_cdb_t));
+	desc->hw_next = NULL;
+	desc->src_cnt = 1;
+	desc->dst_cnt = 1;
+	
+	if (flags & DMA_PREP_INTERRUPT)
+		set_bit(APM82181_DESC_INT, &desc->flags);
+	else
+		clear_bit(APM82181_DESC_INT, &desc->flags);
+	/* dma configuration for running */
+	hw_desc->ctrl.tm = 2; /* soft init mem-mem mode */
+	hw_desc->ctrl.pw = 4; /* transfer width 128 bytes */
+	hw_desc->ctrl.ben = 1;/* buffer enable */
+	hw_desc->ctrl.sai = 1;/* increase source addr */
+	hw_desc->ctrl.dai = 1;/* increase dest addr */
+	hw_desc->ctrl.tce = 1;/* chan stops when TC is reached */
+	hw_desc->ctrl.cp = 3; /* hinghest priority */
+	hw_desc->ctrl.sl = 0; /* source is in PLB */
+	hw_desc->ctrl.pl = 0; /* dest is in PLB */
+	hw_desc->cnt.tcie = 0;/* no interrupt on init */
+	hw_desc->cnt.etie = 0; /* enable error interrupt */
+	hw_desc->cnt.eie = 1; /* enable error interrupt */
+	hw_desc->cnt.link = 0;/* not link to next cdb */
+	hw_desc->cnt.sgl = 0;
+	hw_desc->ctrl.ce =1;  /* enable channel */
+	hw_desc->ctrl.cie =1; /* enable int channel */
+}
+
+/**
+ * apm82181_desc_init_memset - initialize the descriptor for MEMSET operation
+ */
+static inline void apm82181_desc_init_memset(apm82181_desc_t *desc, int value,
+		unsigned long flags)
+{
+	//dma_cdb_t *hw_desc = desc->hw_desc;
+
+	memset (desc->hw_desc, 0, sizeof(dma_cdb_t));
+	desc->hw_next = NULL;
+	desc->src_cnt = 1;
+	desc->dst_cnt = 1;
+
+	if (flags & DMA_PREP_INTERRUPT)
+		set_bit(APM82181_DESC_INT, &desc->flags);
+	else
+		clear_bit(APM82181_DESC_INT, &desc->flags);
+
+}
+
+
+
+/**
+ * apm82181_desc_set_src_addr - set source address into the descriptor
+ */
+static inline void apm82181_desc_set_src_addr( apm82181_desc_t *desc,
+				apm82181_ch_t *chan, int src_idx, dma_addr_t addr)
+{
+	dma_cdb_t *dma_hw_desc;
+	xor_cb_t *xor_hw_desc;
+
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		dma_hw_desc = desc->hw_desc;
+		dma_hw_desc->src_hi = (u32)(addr >> 32);
+		dma_hw_desc->src_lo = (u32)addr;
+		break;
+	case APM82181_XOR_ID:
+		xor_hw_desc = desc->hw_desc;
+                xor_hw_desc->ops[src_idx].h = (u32)(addr >>32);
+                xor_hw_desc->ops[src_idx].l = (u32)addr;
+                break;
+	}
+}
+
+static void apm82181_adma_set_src(apm82181_desc_t *sw_desc,
+                dma_addr_t addr, int index)
+{
+	apm82181_ch_t *chan = to_apm82181_adma_chan(sw_desc->async_tx.chan);
+
+        sw_desc = sw_desc->group_head;
+
+        if (likely(sw_desc))
+                apm82181_desc_set_src_addr(sw_desc, chan, index, addr);
+}
+
+/**
+ * apm82181_desc_set_dest_addr - set destination address into the descriptor
+ */
+static inline void apm82181_desc_set_dest_addr(apm82181_desc_t *desc,
+			apm82181_ch_t *chan, dma_addr_t addr, u32 index)
+{
+	dma_cdb_t *dma_hw_desc;
+	xor_cb_t *xor_hw_desc;
+
+	switch (chan->device->id) {
+        case APM82181_PDMA0_ID:
+        case APM82181_PDMA1_ID:
+        case APM82181_PDMA2_ID:
+        case APM82181_PDMA3_ID:	
+		dma_hw_desc = desc->hw_desc;
+		dma_hw_desc->dest_hi = (u32)(addr >> 32);
+		dma_hw_desc->dest_lo = (u32)addr;
+		break;
+	case APM82181_XOR_ID:
+		xor_hw_desc = desc->hw_desc;
+                xor_hw_desc->cbtah = (u32)(addr >> 32);
+                xor_hw_desc->cbtal |= (u32)addr;
+                break;
+        }
+}
+
+static int plbdma_get_transfer_width(dma_cdb_t *dma_hw_desc)
+{
+	switch (dma_hw_desc->ctrl.pw){
+                case 0:
+                        return 1; /* unit: bytes */
+                case 1:
+                        return 2;
+                case 2:
+                        return 4;
+                case 3:
+                        return 8;
+                case 4:
+                        return 16;
+        }
+	return 0;
+}
+/**
+ * apm82181_desc_set_byte_count - set number of data bytes involved
+ * into the operation
+ */
+static inline void apm82181_desc_set_byte_count(apm82181_desc_t *desc,
+					apm82181_ch_t *chan, size_t byte_count)
+{
+	dma_cdb_t *dma_hw_desc;
+	xor_cb_t *xor_hw_desc;
+	int terminal_cnt, transfer_width = 0;
+	
+	DBG("<%s> byte_count %08x\n", __func__,byte_count);
+	switch (chan->device->id){
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		dma_hw_desc = desc->hw_desc;	
+		transfer_width = plbdma_get_transfer_width(dma_hw_desc);
+		terminal_cnt = byte_count/transfer_width;
+		dma_hw_desc->cnt.tc = terminal_cnt;
+		break;
+	case APM82181_XOR_ID:
+		xor_hw_desc = desc->hw_desc;
+                xor_hw_desc->cbbc = byte_count;
+		break;
+	}
+}
+
+/**
+ * apm82181_xor_set_link - set link address in xor CB
+ */
+static inline void apm82181_xor_set_link (apm82181_desc_t *prev_desc,
+                                                apm82181_desc_t *next_desc)
+{
+        xor_cb_t *xor_hw_desc = prev_desc->hw_desc;
+
+        if (unlikely(!next_desc || !(next_desc->phys))) {
+                printk(KERN_ERR "%s: next_desc=0x%p; next_desc->phys=0x%llx\n",
+                        __func__, next_desc,
+                        next_desc ? next_desc->phys : 0);
+                BUG();
+        }
+	DBG("<%s>:next_desc->phys %llx\n", __func__,next_desc->phys);
+        xor_hw_desc->cbs = 0;
+        xor_hw_desc->cblal = (u32)next_desc->phys;
+        xor_hw_desc->cblah = (u32)(next_desc->phys >> 32);
+        xor_hw_desc->cbc |= XOR_CBCR_LNK_BIT;
+}
+
+/**
+ * apm82181_desc_set_link - set the address of descriptor following this
+ * descriptor in chain
+ */
+static inline void apm82181_desc_set_link(apm82181_ch_t *chan,
+		apm82181_desc_t *prev_desc, apm82181_desc_t *next_desc)
+{
+	unsigned long flags;
+	apm82181_desc_t *tail = next_desc;
+
+	if (unlikely(!prev_desc || !next_desc ||
+		(prev_desc->hw_next && prev_desc->hw_next != next_desc))) {
+		/* If previous next is overwritten something is wrong.
+		 * though we may refetch from append to initiate list
+		 * processing; in this case - it's ok.
+		 */
+		printk(KERN_ERR "%s: prev_desc=0x%p; next_desc=0x%p; "
+			"prev->hw_next=0x%p\n", __FUNCTION__, prev_desc,
+			next_desc, prev_desc ? prev_desc->hw_next : 0);
+		BUG();
+	}
+
+	local_irq_save(flags);
+
+	/* do s/w chaining both for DMA and XOR descriptors */
+	prev_desc->hw_next = next_desc;
+
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		break;
+	 case APM82181_XOR_ID:
+                /* bind descriptor to the chain */
+                while (tail->hw_next)
+                        tail = tail->hw_next;
+                xor_last_linked = tail;
+
+                if (prev_desc == xor_last_submit)
+                        /* do not link to the last submitted CB */
+                        break;
+                apm82181_xor_set_link (prev_desc, next_desc);
+                break;
+	default:
+		BUG();
+	}
+
+	local_irq_restore(flags);
+}
+
+/**
+ * apm82181_desc_get_src_addr - extract the source address from the descriptor
+ */
+static inline u32 apm82181_desc_get_src_addr(apm82181_desc_t *desc,
+					apm82181_ch_t *chan, int src_idx)
+{
+	dma_cdb_t *dma_hw_desc;
+		
+	dma_hw_desc = desc->hw_desc;
+
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		break;
+	default:
+		return 0;
+	}
+		/* May have 0, 1, 2, or 3 sources */
+		return (dma_hw_desc->src_lo); 
+}
+
+/**
+ * apm82181_desc_get_dest_addr - extract the destination address from the
+ * descriptor
+ */
+static inline u32 apm82181_desc_get_dest_addr(apm82181_desc_t *desc,
+		apm82181_ch_t *chan, int idx)
+{
+	dma_cdb_t *dma_hw_desc;
+		
+	dma_hw_desc = desc->hw_desc;
+
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		break;
+	default:
+		return 0;
+	}
+		
+	/* May have 0, 1, 2, or 3 sources */
+	return (dma_hw_desc->dest_lo); 
+}
+
+/**
+ * apm82181_desc_get_byte_count - extract the byte count from the descriptor
+ */
+static inline u32 apm82181_desc_get_byte_count(apm82181_desc_t *desc,
+		apm82181_ch_t *chan)
+{
+	dma_cdb_t *dma_hw_desc;
+		
+	dma_hw_desc = desc->hw_desc;
+
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		break;
+	default:
+		return 0;
+	}
+		/* May have 0, 1, 2, or 3 sources */
+		//return (dma_hw_desc->cnt); 
+}
+
+
+/**
+ * apm82181_desc_get_link - get the address of the descriptor that
+ * follows this one
+ */
+static inline u32 apm82181_desc_get_link(apm82181_desc_t *desc,
+		apm82181_ch_t *chan)
+{
+	if (!desc->hw_next)
+		return 0;
+
+	return desc->hw_next->phys;
+}
+
+/**
+ * apm82181_desc_is_aligned - check alignment
+ */
+static inline int apm82181_desc_is_aligned(apm82181_desc_t *desc,
+		int num_slots)
+{
+	return (desc->idx & (num_slots - 1)) ? 0 : 1;
+}
+
+
+
+/******************************************************************************
+ * ADMA channel low-level routines
+ ******************************************************************************/
+
+static inline phys_addr_t apm82181_chan_get_current_descriptor(apm82181_ch_t *chan);
+static inline void apm82181_chan_append(apm82181_ch_t *chan);
+
+/*
+ * apm82181_adma_device_clear_eot_status - interrupt ack to XOR or DMA engine
+ */
+static inline void apm82181_adma_device_clear_eot_status (apm82181_ch_t *chan)
+{
+	u32 val ;
+	int idx = chan->device->id;
+	volatile xor_regs_t *xor_reg;
+	INFO;
+	switch (idx) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		val = mfdcr(DCR_DMA2P40_SR);
+		if(val & DMA_SR_RI(idx)){
+			printk(KERN_ERR "Err occurred, DMA%d status: 0x%x\n", idx, val);
+		}
+		/* TC reached int, write back to clear */
+		mtdcr(DCR_DMA2P40_SR, val);
+		break;
+	case APM82181_XOR_ID:
+		/* reset status bits to ack*/
+		xor_reg = chan->device->xor_base;
+
+                val = xor_reg->sr;
+		DBG("XOR engine status: 0x%08x\n", val);
+                xor_reg->sr = val;
+
+                if (val & (XOR_IE_ICBIE_BIT|XOR_IE_ICIE_BIT|XOR_IE_RPTIE_BIT)) {
+                        if (val & XOR_IE_RPTIE_BIT) {
+                                /* Read PLB Timeout Error.
+                                 * Try to resubmit the CB
+                                 */
+				INFO;
+                                xor_reg->cblalr = xor_reg->ccbalr;
+                                xor_reg->crsr |= XOR_CRSR_XAE_BIT;
+                        } else
+                                printk (KERN_ERR "XOR ERR 0x%x status\n", val);
+                        break;
+                }
+
+                /*  if the XORcore is idle, but there are unprocessed CBs
+                 * then refetch the s/w chain here
+                 */
+                if (!(xor_reg->sr & XOR_SR_XCP_BIT) && do_xor_refetch) {
+                        apm82181_chan_append(chan);
+                }
+                break;
+        }
+}
+
+/*
+ * apm82181_chan_is_busy - get the channel status
+ */
+
+static inline int apm82181_chan_is_busy(apm82181_ch_t *chan)
+{
+	int busy = 0;
+	volatile xor_regs_t *xor_reg = chan->device->xor_base;
+
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		if(mfdcr(DCR_DMA2P40_SR) & DMA_SR_CB(chan->device->id))
+                	busy = 1;
+        	else
+                	busy = 0;
+		break;
+	case APM82181_XOR_ID:
+		/* use the special status bit for the XORcore
+                 */
+                busy = (xor_reg->sr & XOR_SR_XCP_BIT) ? 1 : 0;
+                break;
+	default:
+		BUG();
+	}
+
+	return busy;
+}
+
+/**
+ * apm82181_dma_put_desc - put PLB DMA 0/1/2/3 descriptor to FIFO
+ */
+static inline void apm82181_dma_put_desc(apm82181_ch_t *chan,
+		apm82181_desc_t *desc)
+{
+	dma_cdb_t *cdb = desc->hw_desc;
+	u32 sg_cmd = 0;
+
+	/* Enable TC interrupt */
+	if(test_bit(APM82181_DESC_INT, &desc->flags))
+		cdb->cnt.tcie = 1;	
+	else
+		cdb->cnt.tcie = 0;
+	/* Not link to next cdb */
+	cdb->sg_hi = 0xffffffff;
+	cdb->sg_lo = 0xffffffff;
+
+	chan_last_sub[chan->device->id] = desc;
+
+	/* Update new cdb addr */
+	mtdcr(DCR_DMA2P40_SGHx(chan->device->id), (u32)(desc->phys >> 32));
+	mtdcr(DCR_DMA2P40_SGLx(chan->device->id), (u32)desc->phys);
+
+	INFO;
+	DBG("slot id: %d addr: %llx\n", desc->idx, desc->phys);
+	DBG("S/G addr H: %08x addr L: %08x\n",
+		mfdcr(DCR_DMA2P40_SGHx(chan->device->id)),
+		mfdcr(DCR_DMA2P40_SGLx(chan->device->id)));
+	ADMA_HEXDUMP(cdb, 96);
+	/* Enable S/G */
+	sg_cmd |= (DMA_SGC_SSG(chan->device->id) | DMA_SGC_EM_ALL);
+	sg_cmd |= DMA_SGC_SGL(chan->device->id, 0); /* S/G addr in PLB */
+		
+	mtdcr(DCR_DMA2P40_SGC, sg_cmd);
+	DBG("S/G addr H: %08x addr L: %08x\n",
+		mfdcr(DCR_DMA2P40_SGHx(chan->device->id)),
+		mfdcr(DCR_DMA2P40_SGLx(chan->device->id)));
+	/* need to use variable for logging current CDB */
+	chan->current_cdb_addr = desc->phys;
+
+}
+
+/**
+ * apm82181_chan_append - update the h/w chain in the channel
+ */
+static inline void apm82181_chan_append(apm82181_ch_t *chan)
+{
+	apm82181_desc_t *iter;
+	volatile xor_regs_t *xor_reg;
+	phys_addr_t cur_desc;
+	xor_cb_t *xcb;
+	unsigned long flags;
+	INFO;
+
+	local_irq_save(flags);
+
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		cur_desc = apm82181_chan_get_current_descriptor(chan);
+		DBG("current_desc %llx\n", cur_desc);
+		if (likely(cur_desc)) {
+			INFO;
+			iter = chan_last_sub[chan->device->id];
+			BUG_ON(!iter);
+		} else {
+			INFO;
+			/* first peer */
+			iter = chan_first_cdb[chan->device->id];
+			BUG_ON(!iter);
+			INFO;
+			apm82181_dma_put_desc(chan, iter);
+			chan->hw_chain_inited = 1;
+		}
+
+		/* is there something new to append */
+		if (!iter->hw_next)
+			break;
+
+		/* flush descriptors from the s/w queue to fifo */
+		list_for_each_entry_continue(iter, &chan->chain, chain_node) {
+			apm82181_dma_put_desc(chan, iter);
+			if (!iter->hw_next)
+				break;
+		}
+		break;
+	case APM82181_XOR_ID:
+		/* update h/w links and refetch */
+                if (!xor_last_submit->hw_next)
+                        break;
+		xor_reg = chan->device->xor_base;
+		/* the last linked CDB has to generate an interrupt
+                 * that we'd be able to append the next lists to h/w
+                 * regardless of the XOR engine state at the moment of
+                 * appending of these next lists
+                 */
+                xcb = xor_last_linked->hw_desc;
+                xcb->cbc |= XOR_CBCR_CBCE_BIT;
+
+                if (!(xor_reg->sr & XOR_SR_XCP_BIT)) {
+                        /* XORcore is idle. Refetch now */
+                        do_xor_refetch = 0;
+                        apm82181_xor_set_link(xor_last_submit,
+                                xor_last_submit->hw_next);
+
+                        xor_last_submit = xor_last_linked;
+                        xor_reg->crsr |= XOR_CRSR_RCBE_BIT | XOR_CRSR_64BA_BIT;
+                } else {
+                        /* XORcore is running. Refetch later in the handler */
+                        do_xor_refetch = 1;
+                }
+
+		break;
+	}
+
+	local_irq_restore(flags);
+}
+
+/**
+ * apm82181_chan_get_current_descriptor - get the currently executed descriptor
+ */
+static inline phys_addr_t apm82181_chan_get_current_descriptor(apm82181_ch_t *chan)
+{
+	phys_addr_t curr_cdb_addr;
+	volatile xor_regs_t *xor_reg;
+	int idx = chan->device->id;
+
+	if (unlikely(!chan->hw_chain_inited))
+		/* h/w descriptor chain is not initialized yet */
+		return 0;
+	switch(idx){
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		curr_cdb_addr = chan->current_cdb_addr;	
+		break;
+	case APM82181_XOR_ID:
+		xor_reg = chan->device->xor_base;
+		curr_cdb_addr = (dma_addr_t)xor_reg->ccbahr; 
+		curr_cdb_addr = (curr_cdb_addr << 32) | xor_reg->ccbalr;
+		break;	
+	default:
+		BUG();
+	}
+	return curr_cdb_addr; 
+}
+
+
+/******************************************************************************
+ * ADMA device level
+ ******************************************************************************/
+
+static int apm82181_adma_alloc_chan_resources(struct dma_chan *chan);
+static dma_cookie_t apm82181_adma_tx_submit(
+		struct dma_async_tx_descriptor *tx);
+
+static void apm82181_adma_set_dest(
+		apm82181_desc_t *tx,
+		dma_addr_t addr, int index);
+
+/**
+ * apm82181_get_group_entry - get group entry with index idx
+ * @tdesc: is the last allocated slot in the group.
+ */
+static inline apm82181_desc_t *
+apm82181_get_group_entry ( apm82181_desc_t *tdesc, u32 entry_idx)
+{
+	apm82181_desc_t *iter = tdesc->group_head;
+	int i = 0;
+
+	if (entry_idx < 0 || entry_idx >= (tdesc->src_cnt + tdesc->dst_cnt)) {
+		printk("%s: entry_idx %d, src_cnt %d, dst_cnt %d\n",
+				__func__, entry_idx, tdesc->src_cnt, tdesc->dst_cnt);
+		BUG();
+	}
+	list_for_each_entry(iter, &tdesc->group_list, chain_node) {
+		if (i++ == entry_idx)
+			break;
+	}
+	return iter;
+}
+
+/**
+ * apm82181_adma_free_slots - flags descriptor slots for reuse
+ * @slot: Slot to free
+ * Caller must hold &apm82181_chan->lock while calling this function
+ */
+static void apm82181_adma_free_slots(apm82181_desc_t *slot,
+		apm82181_ch_t *chan)
+{
+	int stride = slot->slots_per_op;
+
+	while (stride--) {
+		/*async_tx_clear_ack(&slot->async_tx);*/ /* Don't need to clear. It is hack*/
+		slot->slots_per_op = 0;
+		slot = list_entry(slot->slot_node.next,
+				apm82181_desc_t,
+				slot_node);
+	}
+}
+
+static void 
+apm82181_adma_unmap(apm82181_ch_t *chan, apm82181_desc_t *desc)
+{
+	u32 src_cnt, dst_cnt;
+	dma_addr_t addr;
+	/*
+	 * get the number of sources & destination
+	 * included in this descriptor and unmap
+	 * them all
+	 */
+	src_cnt = 1; 
+	dst_cnt = 1; 
+
+	/* unmap destinations */
+	if (!(desc->async_tx.flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+		while (dst_cnt--) {
+			addr = apm82181_desc_get_dest_addr(
+				desc, chan, dst_cnt);
+			dma_unmap_page(&chan->device->ofdev->dev,
+					addr, desc->unmap_len,
+					DMA_FROM_DEVICE);
+		}
+	}
+
+	/* unmap sources */
+	if (!(desc->async_tx.flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+		while (src_cnt--) {
+			addr = apm82181_desc_get_src_addr(
+				desc, chan, src_cnt);
+			dma_unmap_page(&chan->device->ofdev->dev,
+					addr, desc->unmap_len,
+					DMA_TO_DEVICE);
+		}
+	}
+
+}
+/**
+ * apm82181_adma_run_tx_complete_actions - call functions to be called
+ * upon complete
+ */
+static dma_cookie_t apm82181_adma_run_tx_complete_actions(
+		apm82181_desc_t *desc,
+		apm82181_ch_t *chan,
+		dma_cookie_t cookie)
+{
+	int i;
+	//enum dma_data_direction dir;
+	INFO;
+	BUG_ON(desc->async_tx.cookie < 0);
+	if (desc->async_tx.cookie > 0) {
+		cookie = desc->async_tx.cookie;
+		desc->async_tx.cookie = 0;
+
+		/* 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?)
+		 *
+		 * actually, ppc's dma_unmap_page() functions are empty, so
+		 * the following code is just for the sake of completeness
+		 */
+		if (chan && chan->needs_unmap && desc->group_head &&
+		     desc->unmap_len) {
+			apm82181_desc_t *unmap = desc->group_head;
+			/* assume 1 slot per op always */
+			u32 slot_count = unmap->slot_cnt;
+
+			/* Run through the group list and unmap addresses */
+			for (i = 0; i < slot_count; i++) {
+				BUG_ON(!unmap);
+				apm82181_adma_unmap(chan, unmap);
+				unmap = unmap->hw_next;
+			}
+			desc->group_head = NULL;
+		}
+	}
+
+	/* run dependent operations */
+	dma_run_dependencies(&desc->async_tx);
+
+	return cookie;
+}
+
+/**
+ * apm82181_adma_clean_slot - clean up CDB slot (if ack is set)
+ */
+static int apm82181_adma_clean_slot(apm82181_desc_t *desc,
+		apm82181_ch_t *chan)
+{
+	/* the client is allowed to attach dependent operations
+	 * until 'ack' is set
+	 */
+	if (!async_tx_test_ack(&desc->async_tx))
+		return 0;
+
+	/* leave the last descriptor in the chain
+	 * so we can append to it
+	 */
+	if (list_is_last(&desc->chain_node, &chan->chain) ||
+	    desc->phys == apm82181_chan_get_current_descriptor(chan))
+		return 1;
+
+	dev_dbg(chan->device->common.dev, "\tfree slot %llx: %d stride: %d\n",
+		desc->phys, desc->idx, desc->slots_per_op);
+
+	list_del(&desc->chain_node);
+	apm82181_adma_free_slots(desc, chan);
+	return 0;
+}
+
+/**
+ *      __apm82181_adma_slot_cleanup - this is the common clean-up routine
+ *	which runs through the channel CDBs list until reach the descriptor
+ *	currently processed. When routine determines that all CDBs of group
+ *	are completed then corresponding callbacks (if any) are called and slots
+ *	are freed.
+ */
+static void __apm82181_adma_slot_cleanup(apm82181_ch_t *chan)
+{
+	apm82181_desc_t *iter, *_iter, *group_start = NULL;
+	dma_cookie_t cookie = 0;
+	phys_addr_t current_desc = apm82181_chan_get_current_descriptor(chan);
+	int busy = apm82181_chan_is_busy(chan);
+	int seen_current = 0, slot_cnt = 0, slots_per_op = 0;
+
+	DBG("apm82181 adma%d: %s\n",
+		chan->device->id, __FUNCTION__);
+	DBG("current_desc %llx\n", current_desc);
+
+	if (!current_desc) {
+		/*  There were no transactions yet, so
+		 * nothing to clean
+		 */
+		return;
+	}
+
+	/* free completed slots from the chain starting with
+	 * the oldest descriptor
+	 */
+	list_for_each_entry_safe(iter, _iter, &chan->chain,
+					chain_node) {
+		DBG(" cookie: %d slot: %d "
+		    "busy: %d this_desc: %llx next_desc: %x cur: %llx ack: %d\n",
+			iter->async_tx.cookie, iter->idx, busy, iter->phys,
+		    	apm82181_desc_get_link(iter, chan), current_desc,
+			async_tx_test_ack(&iter->async_tx));
+		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, or if it appears that the current descriptor
+		 * needs to be re-read (i.e. has been appended to)
+		 */
+		if (iter->phys == current_desc) {
+			BUG_ON(seen_current++);
+			if (busy || apm82181_desc_get_link(iter, chan)) {
+				/* not all descriptors of the group have
+				 * been completed; exit.
+				 */
+				break;
+			}
+		}
+
+		/* detect the start of a group transaction */
+		if (!slot_cnt && !slots_per_op) {
+			slot_cnt = iter->slot_cnt;
+			slots_per_op = iter->slots_per_op;
+			if (slot_cnt <= slots_per_op) {
+				slot_cnt = 0;
+				slots_per_op = 0;
+			}
+		}
+
+		if (slot_cnt) {
+			if (!group_start)
+				group_start = iter;
+			slot_cnt -= slots_per_op;
+		}
+
+		/* all the members of a group are complete */
+		if (slots_per_op != 0 && slot_cnt == 0) {
+			apm82181_desc_t *grp_iter, *_grp_iter;
+			int end_of_chain = 0;
+
+			/* clean up the group */
+			slot_cnt = group_start->slot_cnt;
+			grp_iter = group_start;
+			list_for_each_entry_safe_from(grp_iter, _grp_iter,
+				&chan->chain, chain_node) {
+
+				cookie = apm82181_adma_run_tx_complete_actions(
+					grp_iter, chan, cookie);
+
+				slot_cnt -= slots_per_op;
+				end_of_chain = apm82181_adma_clean_slot(
+				    grp_iter, chan);
+				if (end_of_chain && slot_cnt) {
+					/* Should wait for ZeroSum complete */
+					if (cookie > 0)
+						chan->completed_cookie = cookie;
+					return;
+				}
+
+				if (slot_cnt == 0 || end_of_chain)
+					break;
+			}
+
+			/* the group should be complete at this point */
+			BUG_ON(slot_cnt);
+
+			slots_per_op = 0;
+			group_start = NULL;
+			if (end_of_chain)
+				break;
+			else
+				continue;
+		} else if (slots_per_op) /* wait for group completion */
+			continue;
+
+		cookie = apm82181_adma_run_tx_complete_actions(iter, chan,
+		    cookie);
+
+		if (apm82181_adma_clean_slot(iter, chan))
+			break;
+	}
+
+	BUG_ON(!seen_current);
+
+	if (cookie > 0) {
+		chan->completed_cookie = cookie;
+		DBG("completed cookie %d\n", cookie);
+	}
+
+}
+
+/**
+ * apm82181_adma_tasklet - clean up watch-dog initiator
+ */
+static void apm82181_adma_tasklet (unsigned long data)
+{
+	apm82181_ch_t *chan = (apm82181_ch_t *) data;
+	spin_lock(&chan->lock);
+	INFO;
+	__apm82181_adma_slot_cleanup(chan);
+	spin_unlock(&chan->lock);
+}
+
+/**
+ * apm82181_adma_slot_cleanup - clean up scheduled initiator
+ */
+static void apm82181_adma_slot_cleanup (apm82181_ch_t *chan)
+{
+	spin_lock_bh(&chan->lock);
+	__apm82181_adma_slot_cleanup(chan);
+	spin_unlock_bh(&chan->lock);
+}
+
+/**
+ * apm82181_adma_alloc_slots - allocate free slots (if any)
+ */
+static apm82181_desc_t *apm82181_adma_alloc_slots(
+		apm82181_ch_t *chan, int num_slots,
+		int slots_per_op)
+{
+	apm82181_desc_t *iter = NULL, *_iter, *alloc_start = NULL;
+	struct list_head chain = LIST_HEAD_INIT(chain);
+	int slots_found, retry = 0;
+
+
+	BUG_ON(!num_slots || !slots_per_op);
+	/* 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 = chan->last_used;
+	else
+		iter = list_entry(&chan->all_slots, apm82181_desc_t,
+			slot_node);
+	prefetch(iter);
+	DBG("---iter at %p idx %d\n ",iter,iter->idx);
+	list_for_each_entry_safe_continue(iter, _iter, &chan->all_slots,
+	    slot_node) {
+		prefetch(_iter);
+		prefetch(&_iter->async_tx);
+		if (iter->slots_per_op) {
+			slots_found = 0;
+			continue;
+		}
+
+		/* start the allocation if the slot is correctly aligned */
+		if (!slots_found++)
+			alloc_start = iter;
+		if (slots_found == num_slots) {
+			apm82181_desc_t *alloc_tail = NULL;
+			apm82181_desc_t *last_used = NULL;
+			iter = alloc_start;
+			while (num_slots) {
+				int i;
+	
+				/* pre-ack all but the last descriptor */
+				if (num_slots != slots_per_op) {
+					async_tx_ack(&iter->async_tx); 
+				}
+				list_add_tail(&iter->chain_node, &chain);
+				alloc_tail = iter;
+				iter->async_tx.cookie = 0;
+				iter->hw_next = NULL;
+				iter->flags = 0;
+				iter->slot_cnt = num_slots;
+				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,
+						apm82181_desc_t,
+						slot_node);
+				}
+				num_slots -= slots_per_op;
+			}
+			alloc_tail->group_head = alloc_start;
+			alloc_tail->async_tx.cookie = -EBUSY;
+			list_splice(&chain, &alloc_tail->group_list);
+			chan->last_used = last_used;
+			DBG("---slot allocated at %llx idx %d, hw_desc %p tx_ack %d\n",
+                                alloc_tail->phys, alloc_tail->idx, alloc_tail->hw_desc, 
+				async_tx_test_ack(&alloc_tail->async_tx));
+			return alloc_tail;
+		}
+	}
+	if (!retry++)
+		goto retry;
+#ifdef ADMA_DEBUG
+	static int empty_slot_cnt;
+	if(!(empty_slot_cnt%100))
+		printk(KERN_INFO"No empty slots trying to free some\n");
+	empty_slot_cnt++;
+#endif
+	/* try to free some slots if the allocation fails */
+	tasklet_schedule(&chan->irq_tasklet);
+	return NULL;
+}
+
+/**
+ * apm82181_chan_xor_slot_count - get the number of slots necessary for
+ * XOR operation
+ */
+static inline int apm82181_chan_xor_slot_count(size_t len, int src_cnt,
+                int *slots_per_op)
+{
+        int slot_cnt;
+
+        /* each XOR descriptor provides up to 16 source operands */
+        slot_cnt = *slots_per_op = (src_cnt + XOR_MAX_OPS - 1)/XOR_MAX_OPS;
+
+        if (likely(len <= APM82181_ADMA_XOR_MAX_BYTE_COUNT))
+                return slot_cnt;
+
+        printk(KERN_ERR "%s: len %d > max %d !!\n",
+                __func__, len, APM82181_ADMA_XOR_MAX_BYTE_COUNT);
+        BUG();
+        return slot_cnt;
+}
+
+/**
+ * apm82181_desc_init_null_xor - initialize the descriptor for NULL XOR
+ * pseudo operation
+ */
+static inline void apm82181_desc_init_null_xor(apm82181_desc_t *desc)
+{
+        memset (desc->hw_desc, 0, sizeof(xor_cb_t));
+        desc->hw_next = NULL;
+        desc->src_cnt = 0;
+        desc->dst_cnt = 1;
+}
+/**
+ * apm82181_chan_set_first_xor_descriptor -  initi XORcore chain
+ */
+static inline void apm82181_chan_set_first_xor_descriptor(apm82181_ch_t *chan,
+                                                apm82181_desc_t *next_desc)
+{
+        volatile xor_regs_t *xor_reg;
+
+        xor_reg = chan->device->xor_base;
+
+        if (xor_reg->sr & XOR_SR_XCP_BIT)
+                printk(KERN_INFO "%s: Warn: XORcore is running "
+                        "when try to set the first CDB!\n",
+                        __func__);
+
+        xor_last_submit = xor_last_linked = next_desc;
+
+        xor_reg->crsr = XOR_CRSR_64BA_BIT;
+
+        xor_reg->cblalr = next_desc->phys;
+        xor_reg->cblahr = 0;
+        xor_reg->cbcr |= XOR_CBCR_LNK_BIT;
+
+        chan->hw_chain_inited = 1;
+}
+/**
+ * apm82181_chan_start_null_xor - initiate the first XOR operation (DMA engines
+ *      use FIFOs (as opposite to chains used in XOR) so this is a XOR
+ *      specific operation)
+ */
+static void apm82181_chan_start_null_xor(apm82181_ch_t *chan)
+{
+        apm82181_desc_t *sw_desc, *group_start;
+        dma_cookie_t cookie;
+        int slot_cnt, slots_per_op;
+        volatile xor_regs_t *xor_reg = chan->device->xor_base;
+
+        dev_dbg(chan->device->common.dev,
+                "apm82181 adma%d: %s\n", chan->device->id, __func__);
+	INFO;
+        spin_lock_bh(&chan->lock);
+        slot_cnt = apm82181_chan_xor_slot_count(0, 2, &slots_per_op);
+        sw_desc = apm82181_adma_alloc_slots(chan, slot_cnt, slots_per_op);
+        if (sw_desc) {
+		INFO;
+                group_start = sw_desc->group_head;
+                list_splice_init(&sw_desc->group_list, &chan->chain);
+                async_tx_ack(&sw_desc->async_tx);
+                apm82181_desc_init_null_xor(group_start);
+		INFO;
+
+                cookie = chan->common.cookie;
+                cookie++;
+                if (cookie <= 1)
+                        cookie = 2;
+
+                /* initialize the completed cookie to be less than
+                 * the most recently used cookie
+                 */
+                chan->completed_cookie = cookie - 1;
+                chan->common.cookie = sw_desc->async_tx.cookie = cookie;
+
+                /* channel should not be busy */
+                BUG_ON(apm82181_chan_is_busy(chan));
+
+                /* set the descriptor address */
+                apm82181_chan_set_first_xor_descriptor(chan, sw_desc);
+
+                /* run the descriptor */
+                xor_reg->crsr = XOR_CRSR_64BA_BIT | XOR_CRSR_XAE_BIT;
+        } else
+                printk(KERN_ERR "apm82181 adma%d"
+                        " failed to allocate null descriptor\n",
+                        chan->device->id);
+        spin_unlock_bh(&chan->lock);
+}
+
+/**
+ * apm82181_adma_alloc_chan_resources -  allocate pools for CDB slots
+ */
+static int apm82181_adma_alloc_chan_resources(struct dma_chan *chan)
+{
+	apm82181_ch_t *apm82181_chan = to_apm82181_adma_chan(chan);
+	apm82181_desc_t *slot = NULL;
+	char *hw_desc;
+	int i, db_sz;
+	int init = apm82181_chan->slots_allocated ? 0 : 1;
+
+	chan->chan_id = apm82181_chan->device->id;
+
+	/* Allocate descriptor slots */
+	i = apm82181_chan->slots_allocated;
+	if (apm82181_chan->device->id != APM82181_XOR_ID)
+		db_sz = sizeof (dma_cdb_t);
+	else
+		db_sz = sizeof (xor_cb_t);
+
+	for (; i < (apm82181_chan->device->pool_size/db_sz); i++) {
+		slot = kzalloc(sizeof(apm82181_desc_t), GFP_KERNEL);
+		if (!slot) {
+			printk(KERN_INFO "APM82181/GT ADMA Channel only initialized"
+				" %d descriptor slots", i--);
+			break;
+		}
+
+		hw_desc = (char *) apm82181_chan->device->dma_desc_pool_virt;
+		slot->hw_desc = (void *) &hw_desc[i * db_sz];
+		dma_async_tx_descriptor_init(&slot->async_tx, chan);
+		slot->async_tx.tx_submit = apm82181_adma_tx_submit;
+		INIT_LIST_HEAD(&slot->chain_node);
+		INIT_LIST_HEAD(&slot->slot_node);
+		INIT_LIST_HEAD(&slot->group_list);
+		slot->phys = apm82181_chan->device->dma_desc_pool + i * db_sz;
+		slot->idx = i;
+		spin_lock_bh(&apm82181_chan->lock);
+		apm82181_chan->slots_allocated++;
+		list_add_tail(&slot->slot_node, &apm82181_chan->all_slots);
+		spin_unlock_bh(&apm82181_chan->lock);
+	}
+
+	if (i && !apm82181_chan->last_used) {
+		apm82181_chan->last_used =
+			list_entry(apm82181_chan->all_slots.next,
+				apm82181_desc_t,
+				slot_node);
+	}
+
+	printk("apm82181 adma%d: allocated %d descriptor slots\n",
+		apm82181_chan->device->id, i);
+
+	/* initialize the channel and the chain with a null operation */
+	if (init) {
+		switch (apm82181_chan->device->id)
+		{
+		apm82181_chan->hw_chain_inited = 0;
+		case APM82181_PDMA0_ID:
+			apm82181_dma_tchan[0] = apm82181_chan;
+			break;
+		case APM82181_PDMA1_ID:
+			apm82181_dma_tchan[1] = apm82181_chan;
+			break;
+		case APM82181_PDMA2_ID:
+			apm82181_dma_tchan[2] = apm82181_chan;
+			break;
+		case APM82181_PDMA3_ID:
+			apm82181_dma_tchan[3] = apm82181_chan;
+			break;
+		case APM82181_XOR_ID:
+			apm82181_dma_tchan[4] = apm82181_chan;
+			apm82181_chan_start_null_xor(apm82181_chan);
+                        break;
+		default:
+			BUG();
+		}
+		apm82181_chan->needs_unmap = 1;
+	}
+
+	return (i > 0) ? i : -ENOMEM;
+}
+
+/**
+ * apm82181_desc_assign_cookie - assign a cookie
+ */
+static dma_cookie_t apm82181_desc_assign_cookie(apm82181_ch_t *chan,
+		apm82181_desc_t *desc)
+{
+	dma_cookie_t cookie = chan->common.cookie;
+	cookie++;
+	if (cookie < 0)
+		cookie = 1;
+	chan->common.cookie = desc->async_tx.cookie = cookie;
+	return cookie;
+}
+
+
+/**
+ * apm82181_adma_check_threshold - append CDBs to h/w chain if threshold
+ *	has been achieved
+ */
+static void apm82181_adma_check_threshold(apm82181_ch_t *chan)
+{
+	dev_dbg(chan->device->common.dev, "apm82181 adma%d: pending: %d\n",
+		chan->device->id, chan->pending);
+	INFO;
+	if (chan->pending >= APM82181_ADMA_THRESHOLD) {
+		chan->pending = 0;
+		apm82181_chan_append(chan);
+	}
+}
+
+/**
+ * apm82181_adma_tx_submit - submit new descriptor group to the channel
+ *	(it's not necessary that descriptors will be submitted to the h/w
+ *	chains too right now)
+ */
+static dma_cookie_t apm82181_adma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	apm82181_desc_t *sw_desc = tx_to_apm82181_adma_slot(tx);
+	apm82181_ch_t *chan = to_apm82181_adma_chan(tx->chan);
+	apm82181_desc_t *group_start, *old_chain_tail;
+	int slot_cnt;
+	int slots_per_op;
+	dma_cookie_t cookie;
+	group_start = sw_desc->group_head;
+	slot_cnt = group_start->slot_cnt;
+	slots_per_op = group_start->slots_per_op;
+	INFO;
+	spin_lock_bh(&chan->lock);
+	cookie = apm82181_desc_assign_cookie(chan, sw_desc);
+
+	if (unlikely(list_empty(&chan->chain))) {
+		/* first peer */
+		list_splice_init(&sw_desc->group_list, &chan->chain);
+		chan_first_cdb[chan->device->id] = group_start;
+	} else {
+		/* isn't first peer, bind CDBs to chain */
+		old_chain_tail = list_entry(chan->chain.prev,
+			apm82181_desc_t, chain_node);
+		list_splice_init(&sw_desc->group_list,
+		    &old_chain_tail->chain_node);
+		/* fix up the hardware chain */
+		apm82181_desc_set_link(chan, old_chain_tail, group_start);
+	}
+
+	/* increment the pending count by the number of operations */
+	chan->pending += slot_cnt / slots_per_op;
+	apm82181_adma_check_threshold(chan);
+	spin_unlock_bh(&chan->lock);
+
+	DBG("apm82181 adma%d:cookie: %d slot: %d tx %p\n",
+		chan->device->id, sw_desc->async_tx.cookie, sw_desc->idx, sw_desc);
+	return cookie;
+}
+/**
+ * apm82181_adma_prep_dma_xor - prepare CDB for a XOR operation
+ */
+static struct dma_async_tx_descriptor *apm82181_adma_prep_dma_xor(
+                struct dma_chan *chan, dma_addr_t dma_dest,
+                dma_addr_t *dma_src, unsigned int src_cnt, size_t len,
+                unsigned long flags)
+{
+	apm82181_ch_t *apm82181_chan = to_apm82181_adma_chan(chan);
+        apm82181_desc_t *sw_desc, *group_start;
+        int slot_cnt, slots_per_op;
+
+#ifdef ADMA_DEBUG
+        printk("\n%s(%d):\n\tsrc: ", __func__,
+                apm82181_chan->device->id);
+        for (slot_cnt=0; slot_cnt < src_cnt; slot_cnt++)
+                printk("0x%llx ", dma_src[slot_cnt]);
+        printk("\n\tdst: 0x%llx\n", dma_dest);
+#endif
+        if (unlikely(!len))
+                return NULL;
+        BUG_ON(unlikely(len > APM82181_ADMA_XOR_MAX_BYTE_COUNT));
+
+        dev_dbg(apm82181_chan->device->common.dev,
+                "apm82181 adma%d: %s src_cnt: %d len: %u int_en: %d\n",
+                apm82181_chan->device->id, __func__, src_cnt, len,
+                flags & DMA_PREP_INTERRUPT ? 1 : 0);
+
+        spin_lock_bh(&apm82181_chan->lock);
+        slot_cnt = apm82181_chan_xor_slot_count(len, src_cnt, &slots_per_op);
+        sw_desc = apm82181_adma_alloc_slots(apm82181_chan, slot_cnt,
+                        slots_per_op);
+        if (sw_desc) {
+                group_start = sw_desc->group_head;
+                apm82181_desc_init_xor(group_start, src_cnt, flags);
+                apm82181_adma_set_dest(group_start, dma_dest, 0);
+                while (src_cnt--)
+                        apm82181_adma_set_src(group_start,
+                                dma_src[src_cnt], src_cnt);
+                apm82181_desc_set_byte_count(group_start, apm82181_chan, len);
+                sw_desc->unmap_len = len;
+                sw_desc->async_tx.flags = flags;
+        }
+        spin_unlock_bh(&apm82181_chan->lock);
+
+        return sw_desc ? &sw_desc->async_tx : NULL;
+}
+/**
+ * apm82181_adma_prep_dma_interrupt - prepare CDB for a pseudo DMA operation
+ */
+static struct dma_async_tx_descriptor *apm82181_adma_prep_dma_interrupt(
+		struct dma_chan *chan, unsigned long flags)
+{
+	apm82181_ch_t *apm82181_chan = to_apm82181_adma_chan(chan);
+	apm82181_desc_t *sw_desc, *group_start;
+	int slot_cnt, slots_per_op;
+
+	dev_dbg(apm82181_chan->device->common.dev,
+		"apm82181 adma%d: %s\n", apm82181_chan->device->id,
+		__FUNCTION__);
+	spin_lock_bh(&apm82181_chan->lock);
+	slot_cnt = slots_per_op = 1;
+	sw_desc = apm82181_adma_alloc_slots(apm82181_chan, slot_cnt,
+			slots_per_op);
+	if (sw_desc) {
+		group_start = sw_desc->group_head;
+		apm82181_desc_init_interrupt(group_start, apm82181_chan);
+		group_start->unmap_len = 0;
+		sw_desc->async_tx.flags = flags;
+	}
+	spin_unlock_bh(&apm82181_chan->lock);
+
+	return sw_desc ? &sw_desc->async_tx : NULL;
+}
+
+/**
+ * apm82181_adma_prep_dma_memcpy - prepare CDB for a MEMCPY operation
+ */
+static struct dma_async_tx_descriptor *apm82181_adma_prep_dma_memcpy(
+		struct dma_chan *chan, dma_addr_t dma_dest,
+		dma_addr_t dma_src, size_t len, unsigned long flags)
+{
+	apm82181_ch_t *apm82181_chan = to_apm82181_adma_chan(chan);
+	apm82181_desc_t *sw_desc, *group_start;
+	int slot_cnt, slots_per_op;
+	if (unlikely(!len))
+		return NULL;
+	BUG_ON(unlikely(len > APM82181_ADMA_DMA_MAX_BYTE_COUNT));
+
+	spin_lock_bh(&apm82181_chan->lock);
+
+	dev_dbg(apm82181_chan->device->common.dev,
+		"apm82181 adma%d: %s len: %u int_en %d \n",
+		apm82181_chan->device->id, __FUNCTION__, len,
+		flags & DMA_PREP_INTERRUPT ? 1 : 0);
+
+	slot_cnt = slots_per_op = 1;
+	sw_desc = apm82181_adma_alloc_slots(apm82181_chan, slot_cnt,
+		slots_per_op);
+	if (sw_desc) {
+		group_start = sw_desc->group_head;
+		flags |= DMA_PREP_INTERRUPT;	
+		apm82181_desc_init_memcpy(group_start, flags);
+		apm82181_adma_set_dest(group_start, dma_dest, 0);
+		apm82181_adma_set_src(group_start, dma_src, 0);
+		apm82181_desc_set_byte_count(group_start, apm82181_chan, len);
+		sw_desc->unmap_len = len;
+		sw_desc->async_tx.flags = flags;
+	}
+	spin_unlock_bh(&apm82181_chan->lock);
+	return sw_desc ? &sw_desc->async_tx : NULL;
+}
+
+/**
+ * apm82181_adma_prep_dma_memset - prepare CDB for a MEMSET operation
+ */
+static struct dma_async_tx_descriptor *apm82181_adma_prep_dma_memset(
+		struct dma_chan *chan, dma_addr_t dma_dest, int value,
+		size_t len, unsigned long flags)
+{
+	apm82181_ch_t *apm82181_chan = to_apm82181_adma_chan(chan);
+	apm82181_desc_t *sw_desc, *group_start;
+	int slot_cnt, slots_per_op;
+	if (unlikely(!len))
+		return NULL;
+	BUG_ON(unlikely(len > APM82181_ADMA_DMA_MAX_BYTE_COUNT));
+
+	spin_lock_bh(&apm82181_chan->lock);
+
+	dev_dbg(apm82181_chan->device->common.dev,
+		"apm82181 adma%d: %s cal: %u len: %u int_en %d\n",
+		apm82181_chan->device->id, __FUNCTION__, value, len,
+		flags & DMA_PREP_INTERRUPT ? 1 : 0);
+
+	slot_cnt = slots_per_op = 1;
+	sw_desc = apm82181_adma_alloc_slots(apm82181_chan, slot_cnt,
+		slots_per_op);
+	if (sw_desc) {
+		group_start = sw_desc->group_head;
+		apm82181_desc_init_memset(group_start, value, flags);
+		apm82181_adma_set_dest(group_start, dma_dest, 0);
+		apm82181_desc_set_byte_count(group_start, apm82181_chan, len);
+		sw_desc->unmap_len = len;
+		sw_desc->async_tx.flags = flags;
+	}
+	spin_unlock_bh(&apm82181_chan->lock);
+
+	return sw_desc ? &sw_desc->async_tx : NULL;
+}
+
+
+/**
+ * apm82181_adma_set_dest - set destination address into descriptor
+ */
+static void apm82181_adma_set_dest(apm82181_desc_t *sw_desc,
+		dma_addr_t addr, int index)
+{
+	apm82181_ch_t *chan = to_apm82181_adma_chan(sw_desc->async_tx.chan);
+	BUG_ON(index >= sw_desc->dst_cnt);
+
+	switch (chan->device->id) {
+	case APM82181_PDMA0_ID:
+	case APM82181_PDMA1_ID:
+	case APM82181_PDMA2_ID:
+	case APM82181_PDMA3_ID:
+		/* to do: support transfers lengths >
+		 * APM82181_ADMA_DMA/XOR_MAX_BYTE_COUNT
+		 */
+		apm82181_desc_set_dest_addr(sw_desc->group_head,
+		//	chan, 0x8, addr, index); // Enabling HB bus
+			chan, addr, index);
+		break;
+	case APM82181_XOR_ID:
+		sw_desc = apm82181_get_group_entry(sw_desc, index);
+		apm82181_desc_set_dest_addr(sw_desc, chan, 
+			addr, index);
+		break;
+	default:
+		BUG();
+	}
+}
+
+
+/**
+ * apm82181_adma_free_chan_resources - free the resources allocated
+ */
+static void apm82181_adma_free_chan_resources(struct dma_chan *chan)
+{
+	apm82181_ch_t *apm82181_chan = to_apm82181_adma_chan(chan);
+	apm82181_desc_t *iter, *_iter;
+	int in_use_descs = 0;
+
+	apm82181_adma_slot_cleanup(apm82181_chan);
+
+	spin_lock_bh(&apm82181_chan->lock);
+	list_for_each_entry_safe(iter, _iter, &apm82181_chan->chain,
+					chain_node) {
+		in_use_descs++;
+		list_del(&iter->chain_node);
+	}
+	list_for_each_entry_safe_reverse(iter, _iter,
+			&apm82181_chan->all_slots, slot_node) {
+		list_del(&iter->slot_node);
+		kfree(iter);
+		apm82181_chan->slots_allocated--;
+	}
+	apm82181_chan->last_used = NULL;
+
+	dev_dbg(apm82181_chan->device->common.dev,
+		"apm82181 adma%d %s slots_allocated %d\n",
+		apm82181_chan->device->id,
+		__FUNCTION__, apm82181_chan->slots_allocated);
+	spin_unlock_bh(&apm82181_chan->lock);
+
+	/* one is ok since we left it on there on purpose */
+	if (in_use_descs > 1)
+		printk(KERN_ERR "GT: Freeing %d in use descriptors!\n",
+			in_use_descs - 1);
+}
+
+/**
+ * apm82181_adma_is_complete - poll the status of an ADMA transaction
+ * @chan: ADMA channel handle
+ * @cookie: ADMA transaction identifier
+ */
+static enum dma_status apm82181_adma_is_complete(struct dma_chan *chan,
+	dma_cookie_t cookie, dma_cookie_t *done, dma_cookie_t *used)
+{
+	apm82181_ch_t *apm82181_chan = to_apm82181_adma_chan(chan);
+	dma_cookie_t last_used;
+	dma_cookie_t last_complete;
+	enum dma_status ret;
+
+	last_used = chan->cookie;
+	last_complete = apm82181_chan->completed_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)
+		return ret;
+
+	apm82181_adma_slot_cleanup(apm82181_chan);
+
+	last_used = chan->cookie;
+	last_complete = apm82181_chan->completed_cookie;
+
+	if (done)
+		*done= last_complete;
+	if (used)
+		*used = last_used;
+
+	return dma_async_is_complete(cookie, last_complete, last_used);
+}
+
+/**
+ * apm82181_adma_eot_handler - end of transfer interrupt handler
+ */
+static irqreturn_t apm82181_adma_eot_handler(int irq, void *data)
+{
+	apm82181_ch_t *chan = data;
+
+	dev_dbg(chan->device->common.dev,
+		"apm82181 adma%d: %s\n", chan->device->id, __FUNCTION__);
+	INFO;
+	if(chan->device->id == APM82181_XOR_ID)
+		tasklet_schedule(&chan->irq_tasklet);
+	apm82181_adma_device_clear_eot_status(chan);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * apm82181_adma_err_handler - DMA error interrupt handler;
+ *	do the same things as a eot handler
+ */
+#if 0
+static irqreturn_t apm82181_adma_err_handler(int irq, void *data)
+{
+	apm82181_ch_t *chan = data;
+	dev_dbg(chan->device->common.dev,
+		"apm82181 adma%d: %s\n", chan->device->id, __FUNCTION__);
+	tasklet_schedule(&chan->irq_tasklet);
+	apm82181_adma_device_clear_eot_status(chan);
+
+	return IRQ_HANDLED;
+}
+#endif
+/**
+ * apm82181_test_callback - called when test operation has been done
+ */
+static void apm82181_test_callback (void *unused)
+{
+	complete(&apm82181_r5_test_comp);
+}
+
+/**
+ * apm82181_adma_issue_pending - flush all pending descriptors to h/w
+ */
+static void apm82181_adma_issue_pending(struct dma_chan *chan)
+{
+	apm82181_ch_t *apm82181_chan = to_apm82181_adma_chan(chan);
+
+	DBG("apm82181 adma%d: %s %d \n", apm82181_chan->device->id,
+	    __FUNCTION__, apm82181_chan->pending);
+	if (apm82181_chan->pending) {
+		apm82181_chan->pending = 0;
+		apm82181_chan_append(apm82181_chan);
+	}
+}
+
+/**
+ * apm82181_adma_remove - remove the asynch device
+ */
+static int __devexit apm82181_pdma_remove(struct platform_device *dev)
+{
+	apm82181_dev_t *device = platform_get_drvdata(dev);
+	struct dma_chan *chan, *_chan;
+	struct ppc_dma_chan_ref *ref, *_ref;
+	apm82181_ch_t *apm82181_chan;
+	int i;
+
+	dma_async_device_unregister(&device->common);
+
+	for (i = 0; i < 3; i++) {
+		u32 irq;
+		irq = platform_get_irq(dev, i);
+		free_irq(irq, device);
+	}
+	
+
+	do {
+		struct resource *res;
+		res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+		release_mem_region(res->start, res->end - res->start);
+	} while (0);
+
+	list_for_each_entry_safe(chan, _chan, &device->common.channels,
+				device_node) {
+		apm82181_chan = to_apm82181_adma_chan(chan);
+		list_del(&chan->device_node);
+		kfree(apm82181_chan);
+	}
+
+	list_for_each_entry_safe(ref, _ref, &ppc_adma_chan_list, node) {
+		list_del(&ref->node);
+		kfree(ref);
+	}
+
+	kfree(device);
+
+	return 0;
+}
+
+static inline void xor_hw_init (apm82181_dev_t *adev)
+{
+	volatile xor_regs_t *xor_reg = adev->xor_base;
+	/* Reset XOR */
+        xor_reg->crsr = XOR_CRSR_XASR_BIT;
+        xor_reg->crrr = XOR_CRSR_64BA_BIT;	
+
+	/* enable XOR engine interrupts */
+        xor_reg->ier = XOR_IE_CBCIE_BIT |
+        	XOR_IE_ICBIE_BIT | XOR_IE_ICIE_BIT | XOR_IE_RPTIE_BIT;
+}
+
+/*
+ * Per channel probe
+ */
+static int __devinit apm82181_dma_per_chan_probe(struct of_device *ofdev,
+		const struct of_device_id *match)
+{
+	int ret = 0, irq;
+	const u32 *index, *dcr_regs, *pool_size;
+	apm82181_plb_dma_t *pdma;
+	apm82181_dev_t *adev;
+	apm82181_ch_t *chan;
+	struct ppc_dma_chan_ref *ref;
+        struct device_node *np = ofdev->node;
+	struct resource res;
+	int len;
+	
+	INFO;	
+	pdma = dev_get_drvdata(ofdev->dev.parent);
+	BUG_ON(!pdma);
+	if ((adev = kzalloc(sizeof(*adev), GFP_KERNEL)) == NULL) {
+		 printk("ERROR:No Free memory for allocating dma channels\n");
+		 ret = -ENOMEM;
+		 goto out;
+	}
+	adev->dev = &ofdev->dev;
+	index = of_get_property(np, "cell-index", NULL);
+        if(!index) {
+                printk(KERN_ERR "adma-channel: Device node %s has missing or invalid "
+                       "cell-index property\n", np->full_name);
+                goto err;
+        }
+	adev->id = (int)*index;
+	/* The XOR engine/PLB DMA 4 channels have different resources/pool_sizes */
+	if (adev->id != APM82181_XOR_ID){
+		dcr_regs = of_get_property(np, "dcr-reg", &len);
+        	if (!dcr_regs || (len != 2 * sizeof(u32))) {
+                	printk(KERN_ERR "plb_dma channel%d: Can't get DCR register base !",
+                        	adev->id);
+                	goto err;
+        	}
+		adev->dcr_base = dcr_regs[0];
+
+		pool_size = of_get_property(np, "pool_size", NULL);
+        	if(!pool_size) {
+                	printk(KERN_ERR "plb_dma channel%d: Device node %s has missing or "
+                       		"invalid pool_size property\n", adev->id, np->full_name);
+                	goto err;
+        	}
+        	adev->pool_size = *pool_size;
+	} else {
+		if (of_address_to_resource(np, 0, &res)) {
+                	printk(KERN_ERR "adma_xor channel%d %s: could not get resource address.\n",
+                        	adev->id,np->full_name);
+                       	goto err;
+               	}
+
+               	DBG("XOR resource start = %llx end = %llx\n", res.start, res.end);
+		adev->xor_base = ioremap(res.start, res.end - res.start + 1);
+		if (!adev->xor_base){
+			printk(KERN_ERR "XOR engine registers memory mapping failed.\n");
+			goto err;
+		}			
+		adev->pool_size = PAGE_SIZE << 1;
+	}
+
+	adev->pdma = pdma;
+	adev->ofdev = ofdev;
+	dev_set_drvdata(&(ofdev->dev),adev);
+
+	switch (adev->id){
+        case APM82181_PDMA0_ID:
+        case APM82181_PDMA1_ID:
+        case APM82181_PDMA2_ID:
+        case APM82181_PDMA3_ID:
+                dma_cap_set(DMA_MEMCPY,adev->cap_mask);
+                break;
+	case APM82181_XOR_ID:
+		dma_cap_set(DMA_XOR,adev->cap_mask);
+		dma_cap_set(DMA_INTERRUPT,adev->cap_mask);
+		break;
+        default:
+                BUG();
+        }
+	/* XOR h/w configuration */
+	if(adev->id == APM82181_XOR_ID)
+		xor_hw_init(adev);
+	/* allocate coherent memory for hardware descriptors
+         * note: writecombine gives slightly better performance, but
+         * requires that we explicitly drain the write buffer
+         */
+	if ((adev->dma_desc_pool_virt = dma_alloc_coherent(&ofdev->dev,
+		adev->pool_size, &adev->dma_desc_pool, GFP_KERNEL)) == NULL) {
+		ret = -ENOMEM;
+		goto err_dma_alloc;
+	}
+	
+	adev->common.cap_mask = adev->cap_mask;
+	INIT_LIST_HEAD(&adev->common.channels);
+        /* set base routines */
+        adev->common.device_alloc_chan_resources =
+            apm82181_adma_alloc_chan_resources;
+        adev->common.device_free_chan_resources =
+            apm82181_adma_free_chan_resources;
+        adev->common.device_is_tx_complete = apm82181_adma_is_complete;
+        adev->common.device_issue_pending = apm82181_adma_issue_pending;
+        adev->common.dev = &ofdev->dev;
+
+	/* set prep routines based on capability */
+        if (dma_has_cap(DMA_MEMCPY, adev->common.cap_mask)) {
+                adev->common.device_prep_dma_memcpy =
+                    apm82181_adma_prep_dma_memcpy;
+        }
+        if (dma_has_cap(DMA_MEMSET, adev->common.cap_mask)) {
+                adev->common.device_prep_dma_memset =
+                    apm82181_adma_prep_dma_memset;
+        }
+
+        if (dma_has_cap(DMA_INTERRUPT, adev->common.cap_mask)) {
+                adev->common.device_prep_dma_interrupt =
+                    apm82181_adma_prep_dma_interrupt;
+        }
+
+	if (dma_has_cap(DMA_XOR, adev->common.cap_mask)) {
+                adev->common.max_xor = XOR_MAX_OPS;
+		adev->common.device_prep_dma_xor = 
+		    apm82181_adma_prep_dma_xor;
+	}
+
+	/* create a channel */
+        if ((chan = kzalloc(sizeof(*chan), GFP_KERNEL)) == NULL) {
+                ret = -ENOMEM;
+                goto err_chan_alloc;
+        }
+        tasklet_init(&chan->irq_tasklet, apm82181_adma_tasklet,
+            (unsigned long)chan);
+	
+	irq = irq_of_parse_and_map(np, 0);
+	switch (adev->id){
+        case 0:
+        	if (irq >= 0) {
+                	ret = request_irq(irq, apm82181_adma_eot_handler,
+                        	IRQF_DISABLED, "adma-chan0", chan);
+                	if (ret) {
+                        	printk("Failed to request IRQ %d\n",irq);
+                        	ret = -EIO;
+                        	goto err_irq;
+			}
+                }
+                break;
+        case 1:
+        	if (irq >= 0) {
+                	ret = request_irq(irq, apm82181_adma_eot_handler,
+                        	IRQF_DISABLED, "adma-chan1", chan);
+                	if (ret) {
+                        	printk("Failed to request IRQ %d\n",irq);
+                        	ret = -EIO;
+                        	goto err_irq;
+			}
+                }
+                break;
+        case 2:
+        	if (irq >= 0) {
+                	ret = request_irq(irq, apm82181_adma_eot_handler,
+                        	IRQF_DISABLED, "adma-chan2", chan);
+                	if (ret) {
+                        	printk("Failed to request IRQ %d\n",irq);
+                        	ret = -EIO;
+                        	goto err_irq;
+			}
+                }
+                break;
+	case 3:
+        	if (irq >= 0) {
+                	ret = request_irq(irq, apm82181_adma_eot_handler,
+                        	IRQF_DISABLED, "adma-chan3", chan);
+                	if (ret) {
+                        	printk("Failed to request IRQ %d\n",irq);
+                        	ret = -EIO;
+                        	goto err_irq;
+			}
+                }
+		break;
+	case 4:
+                if (irq >= 0) {
+                        ret = request_irq(irq, apm82181_adma_eot_handler,
+                                IRQF_DISABLED, "adma-xor", chan);
+                        if (ret) {
+                                printk("Failed to request IRQ %d\n",irq);
+                                ret = -EIO;
+                                goto err_irq;
+                        }
+                }
+                break;
+        default:
+                BUG();
+        }
+
+	spin_lock_init(&chan->lock);
+        chan->device = adev;
+	INIT_LIST_HEAD(&chan->chain);
+        INIT_LIST_HEAD(&chan->all_slots);
+        chan->common.device = &adev->common;
+        list_add_tail(&chan->common.device_node, &adev->common.channels);
+        adev->common.chancnt++;
+	
+	printk( "AMCC(R) APM82181 ADMA Engine found [%d]: "
+          "( capabilities: %s%s%s%s%s%s%s)\n",
+          adev->id,
+          dma_has_cap(DMA_PQ, adev->common.cap_mask) ? "pq_xor " : "",
+          dma_has_cap(DMA_PQ_VAL, adev->common.cap_mask) ? "pq_val " :
+            "",
+          dma_has_cap(DMA_XOR, adev->common.cap_mask) ? "xor " : "",
+          dma_has_cap(DMA_XOR_VAL, adev->common.cap_mask) ? "xor_val " :
+            "",
+          dma_has_cap(DMA_MEMSET, adev->common.cap_mask)  ? "memset " : "",
+          dma_has_cap(DMA_MEMCPY, adev->common.cap_mask) ? "memcpy " : "",
+          dma_has_cap(DMA_INTERRUPT, adev->common.cap_mask) ? "int " : "");
+	INFO;
+        ret = dma_async_device_register(&adev->common);
+        if (ret) {
+                dev_err(&ofdev->dev, "failed to register dma async device");
+                goto err_irq;
+        }
+	INFO;
+        ref = kmalloc(sizeof(*ref), GFP_KERNEL);
+        if (ref) {
+                INFO;
+                ref->chan = &chan->common;
+                INIT_LIST_HEAD(&ref->node);
+                list_add_tail(&ref->node, &ppc_adma_chan_list);
+        } else
+                dev_warn(&ofdev->dev, "failed to allocate channel reference!\n");
+
+	goto out;
+err_irq:
+	kfree(chan);
+err_chan_alloc:
+	dma_free_coherent(&ofdev->dev, adev->pool_size,
+                        adev->dma_desc_pool_virt, adev->dma_desc_pool);
+err_dma_alloc:
+	if (adev->xor_base)
+		iounmap(adev->xor_base);	
+err:
+	kfree(adev);
+out:
+	return ret;
+}
+
+static struct of_device_id dma_4chan_match[] = 
+{
+	{
+		.compatible     = "amcc,apm82181-adma",
+	},
+	{},
+};
+
+static struct of_device_id dma_per_chan_match[] = {
+	{.compatible = "amcc,apm82181-dma-4channel",},
+	{.compatible = "amcc,xor",},
+	{},
+};
+/*
+ * apm82181_adma_probe - probe the asynch device
+ */
+static int __devinit apm82181_pdma_probe(struct of_device *ofdev,
+		const struct of_device_id *match)
+{
+	int ret = 0; 
+	apm82181_plb_dma_t *pdma;
+
+	if ((pdma = kzalloc(sizeof(*pdma), GFP_KERNEL)) == NULL) {
+		 ret = -ENOMEM; 
+		 goto out;
+	}
+	pdma->dev = &ofdev->dev;
+	pdma->ofdev = ofdev;
+	printk(PPC4XX_EDMA "Probing AMCC APM82181 ADMA engines...\n");
+
+	dev_set_drvdata(&(ofdev->dev),pdma);
+	of_platform_bus_probe(ofdev->node, dma_per_chan_match,&ofdev->dev);
+
+out:
+	return ret;
+}
+
+/*
+ * apm82181_test_xor - test are RAID-5 XOR capability enabled successfully.
+ *      For this we just perform one DMA XOR operation with the 3 sources
+ *      to a destination 
+ */
+static int apm82181_test_xor (apm82181_ch_t *chan)
+{
+        apm82181_desc_t *sw_desc, *group_start;
+        struct page *pg_src[3], *pg_dest;
+        char *a;
+        dma_addr_t dma_src_addr[3];
+        dma_addr_t dma_dst_addr;
+        int rval = -EFAULT, i;
+        int len = PAGE_SIZE, src_cnt = 3;
+	int slot_cnt, slots_per_op;
+	INFO;
+        printk("ADMA channel %d XOR testing\n",chan->device->id);
+	for(i = 0; i < 3; i++){
+        	pg_src[i] = alloc_page(GFP_KERNEL);
+        	if (!pg_src[i])
+                	return -ENOMEM;
+	}
+        pg_dest = alloc_page(GFP_KERNEL);
+        if (!pg_dest)
+                return -ENOMEM;
+        /* Fill the test page with ones */
+        memset(page_address(pg_src[0]), 0xDA, len);
+        memset(page_address(pg_src[1]), 0xDA, len);
+        memset(page_address(pg_src[2]), 0x00, len);
+        memset(page_address(pg_dest), 0xA5, len);
+	for(i = 0; i < 3; i++){
+        	a = page_address(pg_src[i]);
+        	printk("The virtual addr of src %d =%x\n",i, (unsigned int)a);
+        	MEM_HEXDUMP(a,50);
+	}
+        a = page_address(pg_dest);
+        printk("The virtual addr of dest=%x\n", (unsigned int)a);
+        MEM_HEXDUMP(a,50);
+
+	for(i = 0; i < 3; i++){
+        	dma_src_addr[i] = dma_map_page(chan->device->dev, pg_src[i], 0, len,
+            		DMA_BIDIRECTIONAL);
+	}
+        dma_dst_addr = dma_map_page(chan->device->dev, pg_dest, 0, len,
+            DMA_BIDIRECTIONAL);
+        printk("dma_src_addr[0]: %llx; dma_src_addr[1]: %llx;\n "
+		"dma_src_addr[2]: %llx; dma_dst_addr %llx, len: %x\n", dma_src_addr[0],
+		dma_src_addr[1], dma_src_addr[2], dma_dst_addr, len);
+
+        spin_lock_bh(&chan->lock);
+	slot_cnt = apm82181_chan_xor_slot_count(len, src_cnt, &slots_per_op);
+        sw_desc = apm82181_adma_alloc_slots(chan, slot_cnt, slots_per_op);
+        if (sw_desc) {
+		group_start = sw_desc->group_head;
+                apm82181_desc_init_xor(group_start, src_cnt, DMA_PREP_INTERRUPT);
+                /* Setup addresses */
+		while (src_cnt--)
+                        apm82181_adma_set_src(group_start,
+                                dma_src_addr[src_cnt], src_cnt);
+                apm82181_adma_set_dest(group_start, dma_dst_addr, 0);
+                apm82181_desc_set_byte_count(group_start, chan, len);
+                sw_desc->unmap_len = PAGE_SIZE;
+        } else {
+		rval = -EFAULT;
+                spin_unlock_bh(&chan->lock);
+                goto exit;
+        }
+        spin_unlock_bh(&chan->lock);
+
+        printk("Submit CDB...\n");
+        MEM_HEXDUMP(sw_desc->hw_desc, 96);
+        async_tx_ack(&sw_desc->async_tx);
+        sw_desc->async_tx.callback = apm82181_test_callback;
+        sw_desc->async_tx.callback_param = NULL;
+
+        init_completion(&apm82181_r5_test_comp);
+        apm82181_adma_tx_submit(&sw_desc->async_tx);
+        apm82181_adma_issue_pending(&chan->common);
+        //wait_for_completion(&apm82181_r5_test_comp);
+	/* wait for a while so that dma transaction finishes */
+	mdelay(100);
+	/* Now check if the test page zeroed */
+        a = page_address(pg_dest);
+	/* XOR result at destination */
+        MEM_HEXDUMP(a,50);
+        if ((*(u32*)a) == 0x00000000 && memcmp(a, a+4, PAGE_SIZE-4)==0) {
+                /* page dest XOR is corect as expected - RAID-5 enabled */
+                rval = 0;
+        } else {
+                /* RAID-5 was not enabled */
+                rval = -EINVAL;
+        }
+
+exit:
+	dma_unmap_page(chan->device->dev, dma_src_addr[0], PAGE_SIZE, DMA_BIDIRECTIONAL);
+        dma_unmap_page(chan->device->dev, dma_src_addr[1], PAGE_SIZE, DMA_BIDIRECTIONAL);
+        dma_unmap_page(chan->device->dev, dma_src_addr[2], PAGE_SIZE, DMA_BIDIRECTIONAL);
+        dma_unmap_page(chan->device->dev, dma_dst_addr, PAGE_SIZE, DMA_BIDIRECTIONAL);
+        __free_page(pg_src[0]);
+        __free_page(pg_src[1]);
+        __free_page(pg_src[2]);
+        __free_page(pg_dest);
+        return rval;
+}
+
+
+/*
+ * apm82181_test_dma - test are RAID-5 capabilities enabled successfully.
+ *	For this we just perform one WXOR operation with the same source
+ *	and destination addresses, the GF-multiplier is 1; so if RAID-5
+	o/of_platform_driver_unregister(&apm82181_pdma_driver);
+ *	capabilities are enabled then we'll get src/dst filled with zero.
+ */
+static int apm82181_test_dma (apm82181_ch_t *chan)
+{
+	apm82181_desc_t *sw_desc;
+	struct page *pg_src, *pg_dest;
+	char *a, *d;
+	dma_addr_t dma_src_addr;
+	dma_addr_t dma_dst_addr;
+	int rval = -EFAULT;
+	int len = PAGE_SIZE;
+
+	printk("PLB DMA channel %d memcpy testing\n",chan->device->id);
+	pg_src = alloc_page(GFP_KERNEL);
+	if (!pg_src)
+		return -ENOMEM;
+	pg_dest = alloc_page(GFP_KERNEL);
+	if (!pg_dest)
+		return -ENOMEM;
+	/* Fill the test page with ones */
+	memset(page_address(pg_src), 0x77, len);
+	memset(page_address(pg_dest), 0xa5, len);
+	a = page_address(pg_src);
+        printk("The virtual addr of src =%x\n", (unsigned int)a);
+        MEM_HEXDUMP(a,50);
+        a = page_address(pg_dest);
+        printk("The virtual addr of dest=%x\n", (unsigned int)a);
+        MEM_HEXDUMP(a,50);
+	dma_src_addr = dma_map_page(chan->device->dev, pg_src, 0, len,
+	    DMA_BIDIRECTIONAL);
+	dma_dst_addr = dma_map_page(chan->device->dev, pg_dest, 0, len,
+	    DMA_BIDIRECTIONAL);
+	printk("dma_src_addr: %llx; dma_dst_addr %llx\n", dma_src_addr, dma_dst_addr);
+
+	spin_lock_bh(&chan->lock);
+	sw_desc = apm82181_adma_alloc_slots(chan, 1, 1);
+	if (sw_desc) {
+		/* 1 src, 1 dst, int_ena */
+		apm82181_desc_init_memcpy(sw_desc, DMA_PREP_INTERRUPT);
+		//apm82181_desc_init_memcpy(sw_desc, 0);
+		/* Setup adresses */
+		apm82181_adma_set_src(sw_desc, dma_src_addr, 0);
+		apm82181_adma_set_dest(sw_desc, dma_dst_addr, 0);
+		apm82181_desc_set_byte_count(sw_desc, chan, len);
+		sw_desc->unmap_len = PAGE_SIZE;
+	} else {
+		rval = -EFAULT;
+		spin_unlock_bh(&chan->lock);
+		goto exit;
+	}
+	spin_unlock_bh(&chan->lock);
+
+	printk("Submit CDB...\n");
+	MEM_HEXDUMP(sw_desc->hw_desc, 96);
+	async_tx_ack(&sw_desc->async_tx);
+	sw_desc->async_tx.callback = apm82181_test_callback;
+	sw_desc->async_tx.callback_param = NULL;
+
+	init_completion(&apm82181_r5_test_comp);
+	apm82181_adma_tx_submit(&sw_desc->async_tx);
+	apm82181_adma_issue_pending(&chan->common);
+	//wait_for_completion(&apm82181_r5_test_comp);
+	
+	a = page_address(pg_src);
+        d = page_address(pg_dest);
+        if (!memcmp(a, d, len)) {
+                rval = 0;
+        } else {
+                rval = -EINVAL;
+        }
+
+        a = page_address(pg_src);
+        printk("\nAfter DMA done:");
+        printk("\nsrc %x value:\n", (unsigned int)a);
+        MEM_HEXDUMP(a,96);
+        a = page_address(pg_dest);
+        printk("\ndest%x value:\n", (unsigned int)a);
+        MEM_HEXDUMP(a,96);
+
+exit:
+	__free_page(pg_src);
+	__free_page(pg_dest);
+	return rval;
+}
+
+static struct of_platform_driver apm82181_pdma_driver = {
+	.name		= "apm82181_plb_dma",
+	.match_table = dma_4chan_match,
+
+	.probe		= apm82181_pdma_probe,
+	//.remove		= apm82181_pdma_remove,
+};
+struct of_platform_driver apm82181_dma_per_chan_driver = {
+	.name = "apm82181-dma-4channel",
+	.match_table = dma_per_chan_match,
+	.probe = apm82181_dma_per_chan_probe,
+};
+
+static int apm82181_xor_read (char *page, char **start, off_t off,
+        int count, int *eof, void *data)
+{
+        char *p = page;
+
+        p += sprintf(p, "%s\n",
+                apm82181_xor_verified ?
+                "APM82181 ASYNC XOR capability are VERIFIED.\n" :
+                "APM82181 ASYNC XOR capability are NOT VERIFIED.\n");
+
+        return p - page;
+}
+
+static int apm82181_xor_write (struct file *file, const char __user *buffer,
+        unsigned long count, void *data)
+{
+        if(count != 2)
+                return -EFAULT;
+        /* Verify does it really work now */
+        if (!apm82181_test_xor(apm82181_dma_tchan[4])) {
+                /* APM82181 RAID-5 XOR has been activated successfully */;
+                printk("APM82181 ADMA XOR engine has been verified "
+                        "successfully\n");
+                apm82181_xor_verified = 1;
+        } else {
+                /* APM82181 RAID-5 memcpy hasn't been activated! */;
+                printk("APM82181 ADMA XOR engine hasn't been "
+                        "verified yet\n");
+                apm82181_xor_verified = 0;
+        }
+
+        return count;
+}
+
+static int apm82181_dma_read (char *page, char **start, off_t off,
+	int count, int *eof, void *data)
+{
+	int i;
+
+        printk("APM82181 ASYNC MEMCPY capability\n");
+        for(i = 0; i < 4; i++){
+                printk("\tPLB DMA channel %d: %s ", i,
+                        apm82181_memcpy_verified[i] ?
+                        "VERIFIED.\n" : "NOT VERIFIED.\n");
+        }
+        return 0;
+}
+
+static int apm82181_dma_write (struct file *file, const char __user *buffer,
+	unsigned long count, void *data)
+{
+	/* e.g. 0xffffffff */
+	char tmp[2];
+	u32 val;
+
+	if(count != 2)
+		return -EFAULT;
+
+	if (copy_from_user(tmp, buffer, count))
+		return -EFAULT;
+	val = simple_strtoul(tmp, NULL, 10); /* decimal base */
+	if(!(val == 0 || val == 1 || val == 2 || val == 3 )) {
+                printk("Error! Wrong channel id, please choose 1 valid id [0/1/2/3]\n");
+                return -EFAULT;
+        }
+
+	/* Verify does it really work now */
+	if (!apm82181_test_dma(apm82181_dma_tchan[val])) {
+		/* APM82181 RAID-5 memcpy has been activated successfully */;
+		printk("APM82181 PLBDMA MEMCPY channel %d has been verified "
+			"successfully\n", val);
+		apm82181_memcpy_verified[val] = 1;
+	} else {
+		/* APM82181 RAID-5 memcpy hasn't been activated! */;
+		printk("APM82181 PLBDMA MEMCPY channel %d hasn't been "
+			"verified yet\n", val);
+		apm82181_memcpy_verified[val] = 0;
+	}
+
+	return count;
+}
+
+static int __init apm82181_adma_per_chan_init (void)
+{
+        int rval;
+	rval = of_register_platform_driver(&apm82181_dma_per_chan_driver);
+	return rval;
+}
+
+static int __init apm82181_adma_init (void)
+{
+	int rval;
+	struct proc_dir_entry *p;
+
+	rval = of_register_platform_driver(&apm82181_pdma_driver);
+
+	if (rval == 0) {
+		/* Create /proc entries */
+		apm82181_proot = proc_mkdir(APM82181_DMA_PROC_ROOT, NULL);
+		if (!apm82181_proot) {
+			printk(KERN_ERR "%s: failed to create %s proc "
+			    "directory\n",__FUNCTION__,APM82181_DMA_PROC_ROOT);
+			/* User will not be able to enable h/w RAID-6 */
+			return rval;
+		}
+
+		/* ADMA MEMCPY verification entry */
+		p = create_proc_entry("adma_memcopy_test", 0, apm82181_proot);
+		if (p) {
+			p->read_proc = apm82181_dma_read;
+			p->write_proc = apm82181_dma_write;
+		}
+		/* ADMA XOR capability verification entry */
+		p = create_proc_entry("adma_xor_test", 0, apm82181_proot);
+		if (p) {
+			p->read_proc = apm82181_xor_read;
+			p->write_proc = apm82181_xor_write;
+		}
+	}
+	return rval;
+}
+
+#if 0
+static void __exit apm82181_adma_exit (void)
+{
+	of_unregister_platform_driver(&apm82181_pdma_driver);
+	return;
+}
+module_exit(apm82181_adma_exit);
+#endif
+
+module_init(apm82181_adma_per_chan_init);
+module_init(apm82181_adma_init);
+
+MODULE_AUTHOR("Tai Tri Nguyen<ttnguyen@appliedmicro.com>");
+MODULE_DESCRIPTION("APM82181 ADMA Engine Driver");
+MODULE_LICENSE("GPL");