text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * Applied Micro X-Gene SoC DMA engine Driver
   *
   * Copyright (c) 2015, Applied Micro Circuits Corporation
   * Authors: Rameshwar Prasad Sahu <rsahu@apm.com>
   *	    Loc Ho <lho@apm.com>
   *
   * NOTE: PM support is currently not available.
   */
  
  #include <linux/acpi.h>
  #include <linux/clk.h>
  #include <linux/delay.h>
  #include <linux/dma-mapping.h>
  #include <linux/dmaengine.h>
  #include <linux/dmapool.h>
  #include <linux/interrupt.h>
  #include <linux/io.h>
  #include <linux/irq.h>
  #include <linux/module.h>
  #include <linux/of_device.h>
  
  #include "dmaengine.h"
  
  /* X-Gene DMA ring csr registers and bit definations */
  #define XGENE_DMA_RING_CONFIG			0x04
  #define XGENE_DMA_RING_ENABLE			BIT(31)
  #define XGENE_DMA_RING_ID			0x08
  #define XGENE_DMA_RING_ID_SETUP(v)		((v) | BIT(31))
  #define XGENE_DMA_RING_ID_BUF			0x0C
  #define XGENE_DMA_RING_ID_BUF_SETUP(v)		(((v) << 9) | BIT(21))
  #define XGENE_DMA_RING_THRESLD0_SET1		0x30
  #define XGENE_DMA_RING_THRESLD0_SET1_VAL	0X64
  #define XGENE_DMA_RING_THRESLD1_SET1		0x34
  #define XGENE_DMA_RING_THRESLD1_SET1_VAL	0xC8
  #define XGENE_DMA_RING_HYSTERESIS		0x68
  #define XGENE_DMA_RING_HYSTERESIS_VAL		0xFFFFFFFF
  #define XGENE_DMA_RING_STATE			0x6C
  #define XGENE_DMA_RING_STATE_WR_BASE		0x70
  #define XGENE_DMA_RING_NE_INT_MODE		0x017C
  #define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)	\
  	((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
  #define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v)	\
  	((m) &= (~BIT(31 - (v))))
  #define XGENE_DMA_RING_CLKEN			0xC208
  #define XGENE_DMA_RING_SRST			0xC200
  #define XGENE_DMA_RING_MEM_RAM_SHUTDOWN		0xD070
  #define XGENE_DMA_RING_BLK_MEM_RDY		0xD074
  #define XGENE_DMA_RING_BLK_MEM_RDY_VAL		0xFFFFFFFF
  #define XGENE_DMA_RING_ID_GET(owner, num)	(((owner) << 6) | (num))
  #define XGENE_DMA_RING_DST_ID(v)		((1 << 10) | (v))
  #define XGENE_DMA_RING_CMD_OFFSET		0x2C
  #define XGENE_DMA_RING_CMD_BASE_OFFSET(v)	((v) << 6)
  #define XGENE_DMA_RING_COHERENT_SET(m)		\
  	(((u32 *)(m))[2] |= BIT(4))
  #define XGENE_DMA_RING_ADDRL_SET(m, v)		\
  	(((u32 *)(m))[2] |= (((v) >> 8) << 5))
  #define XGENE_DMA_RING_ADDRH_SET(m, v)		\
  	(((u32 *)(m))[3] |= ((v) >> 35))
  #define XGENE_DMA_RING_ACCEPTLERR_SET(m)	\
  	(((u32 *)(m))[3] |= BIT(19))
  #define XGENE_DMA_RING_SIZE_SET(m, v)		\
  	(((u32 *)(m))[3] |= ((v) << 23))
  #define XGENE_DMA_RING_RECOMBBUF_SET(m)		\
  	(((u32 *)(m))[3] |= BIT(27))
  #define XGENE_DMA_RING_RECOMTIMEOUTL_SET(m)	\
  	(((u32 *)(m))[3] |= (0x7 << 28))
  #define XGENE_DMA_RING_RECOMTIMEOUTH_SET(m)	\
  	(((u32 *)(m))[4] |= 0x3)
  #define XGENE_DMA_RING_SELTHRSH_SET(m)		\
  	(((u32 *)(m))[4] |= BIT(3))
  #define XGENE_DMA_RING_TYPE_SET(m, v)		\
  	(((u32 *)(m))[4] |= ((v) << 19))
  
  /* X-Gene DMA device csr registers and bit definitions */
  #define XGENE_DMA_IPBRR				0x0
  #define XGENE_DMA_DEV_ID_RD(v)			((v) & 0x00000FFF)
  #define XGENE_DMA_BUS_ID_RD(v)			(((v) >> 12) & 3)
  #define XGENE_DMA_REV_NO_RD(v)			(((v) >> 14) & 3)
  #define XGENE_DMA_GCR				0x10
  #define XGENE_DMA_CH_SETUP(v)			\
  	((v) = ((v) & ~0x000FFFFF) | 0x000AAFFF)
  #define XGENE_DMA_ENABLE(v)			((v) |= BIT(31))
  #define XGENE_DMA_DISABLE(v)			((v) &= ~BIT(31))
  #define XGENE_DMA_RAID6_CONT			0x14
  #define XGENE_DMA_RAID6_MULTI_CTRL(v)		((v) << 24)
  #define XGENE_DMA_INT				0x70
  #define XGENE_DMA_INT_MASK			0x74
  #define XGENE_DMA_INT_ALL_MASK			0xFFFFFFFF
  #define XGENE_DMA_INT_ALL_UNMASK		0x0
  #define XGENE_DMA_INT_MASK_SHIFT		0x14
  #define XGENE_DMA_RING_INT0_MASK		0x90A0
  #define XGENE_DMA_RING_INT1_MASK		0x90A8
  #define XGENE_DMA_RING_INT2_MASK		0x90B0
  #define XGENE_DMA_RING_INT3_MASK		0x90B8
  #define XGENE_DMA_RING_INT4_MASK		0x90C0
  #define XGENE_DMA_CFG_RING_WQ_ASSOC		0x90E0
  #define XGENE_DMA_ASSOC_RING_MNGR1		0xFFFFFFFF
  #define XGENE_DMA_MEM_RAM_SHUTDOWN		0xD070
  #define XGENE_DMA_BLK_MEM_RDY			0xD074
  #define XGENE_DMA_BLK_MEM_RDY_VAL		0xFFFFFFFF
  #define XGENE_DMA_RING_CMD_SM_OFFSET		0x8000
  
  /* X-Gene SoC EFUSE csr register and bit defination */
  #define XGENE_SOC_JTAG1_SHADOW			0x18
  #define XGENE_DMA_PQ_DISABLE_MASK		BIT(13)
  
  /* X-Gene DMA Descriptor format */
  #define XGENE_DMA_DESC_NV_BIT			BIT_ULL(50)
  #define XGENE_DMA_DESC_IN_BIT			BIT_ULL(55)
  #define XGENE_DMA_DESC_C_BIT			BIT_ULL(63)
  #define XGENE_DMA_DESC_DR_BIT			BIT_ULL(61)
  #define XGENE_DMA_DESC_ELERR_POS		46
  #define XGENE_DMA_DESC_RTYPE_POS		56
  #define XGENE_DMA_DESC_LERR_POS			60
  #define XGENE_DMA_DESC_BUFLEN_POS		48
  #define XGENE_DMA_DESC_HOENQ_NUM_POS		48
  #define XGENE_DMA_DESC_ELERR_RD(m)		\
  	(((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
  #define XGENE_DMA_DESC_LERR_RD(m)		\
  	(((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
  #define XGENE_DMA_DESC_STATUS(elerr, lerr)	\
  	(((elerr) << 4) | (lerr))
  
  /* X-Gene DMA descriptor empty s/w signature */
  #define XGENE_DMA_DESC_EMPTY_SIGNATURE		~0ULL
  
  /* X-Gene DMA configurable parameters defines */
  #define XGENE_DMA_RING_NUM		512
  #define XGENE_DMA_BUFNUM		0x0
  #define XGENE_DMA_CPU_BUFNUM		0x18
  #define XGENE_DMA_RING_OWNER_DMA	0x03
  #define XGENE_DMA_RING_OWNER_CPU	0x0F
  #define XGENE_DMA_RING_TYPE_REGULAR	0x01
  #define XGENE_DMA_RING_WQ_DESC_SIZE	32	/* 32 Bytes */
  #define XGENE_DMA_RING_NUM_CONFIG	5
  #define XGENE_DMA_MAX_CHANNEL		4
  #define XGENE_DMA_XOR_CHANNEL		0
  #define XGENE_DMA_PQ_CHANNEL		1
  #define XGENE_DMA_MAX_BYTE_CNT		0x4000	/* 16 KB */
  #define XGENE_DMA_MAX_64B_DESC_BYTE_CNT	0x14000	/* 80 KB */
  #define XGENE_DMA_MAX_XOR_SRC		5
  #define XGENE_DMA_16K_BUFFER_LEN_CODE	0x0
  #define XGENE_DMA_INVALID_LEN_CODE	0x7800000000000000ULL
  
  /* X-Gene DMA descriptor error codes */
  #define ERR_DESC_AXI			0x01
  #define ERR_BAD_DESC			0x02
  #define ERR_READ_DATA_AXI		0x03
  #define ERR_WRITE_DATA_AXI		0x04
  #define ERR_FBP_TIMEOUT			0x05
  #define ERR_ECC				0x06
  #define ERR_DIFF_SIZE			0x08
  #define ERR_SCT_GAT_LEN			0x09
  #define ERR_CRC_ERR			0x11
  #define ERR_CHKSUM			0x12
  #define ERR_DIF				0x13
  
  /* X-Gene DMA error interrupt codes */
  #define ERR_DIF_SIZE_INT		0x0
  #define ERR_GS_ERR_INT			0x1
  #define ERR_FPB_TIMEO_INT		0x2
  #define ERR_WFIFO_OVF_INT		0x3
  #define ERR_RFIFO_OVF_INT		0x4
  #define ERR_WR_TIMEO_INT		0x5
  #define ERR_RD_TIMEO_INT		0x6
  #define ERR_WR_ERR_INT			0x7
  #define ERR_RD_ERR_INT			0x8
  #define ERR_BAD_DESC_INT		0x9
  #define ERR_DESC_DST_INT		0xA
  #define ERR_DESC_SRC_INT		0xB
  
  /* X-Gene DMA flyby operation code */
  #define FLYBY_2SRC_XOR			0x80
  #define FLYBY_3SRC_XOR			0x90
  #define FLYBY_4SRC_XOR			0xA0
  #define FLYBY_5SRC_XOR			0xB0
  
  /* X-Gene DMA SW descriptor flags */
  #define XGENE_DMA_FLAG_64B_DESC		BIT(0)
  
  /* Define to dump X-Gene DMA descriptor */
  #define XGENE_DMA_DESC_DUMP(desc, m)	\
  	print_hex_dump(KERN_ERR, (m),	\
  			DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
  
  #define to_dma_desc_sw(tx)		\
  	container_of(tx, struct xgene_dma_desc_sw, tx)
  #define to_dma_chan(dchan)		\
  	container_of(dchan, struct xgene_dma_chan, dma_chan)
  
  #define chan_dbg(chan, fmt, arg...)	\
  	dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
  #define chan_err(chan, fmt, arg...)	\
  	dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
  
  struct xgene_dma_desc_hw {
  	__le64 m0;
  	__le64 m1;
  	__le64 m2;
  	__le64 m3;
  };
  
  enum xgene_dma_ring_cfgsize {
  	XGENE_DMA_RING_CFG_SIZE_512B,
  	XGENE_DMA_RING_CFG_SIZE_2KB,
  	XGENE_DMA_RING_CFG_SIZE_16KB,
  	XGENE_DMA_RING_CFG_SIZE_64KB,
  	XGENE_DMA_RING_CFG_SIZE_512KB,
  	XGENE_DMA_RING_CFG_SIZE_INVALID
  };
  
  struct xgene_dma_ring {
  	struct xgene_dma *pdma;
  	u8 buf_num;
  	u16 id;
  	u16 num;
  	u16 head;
  	u16 owner;
  	u16 slots;
  	u16 dst_ring_num;
  	u32 size;
  	void __iomem *cmd;
  	void __iomem *cmd_base;
  	dma_addr_t desc_paddr;
  	u32 state[XGENE_DMA_RING_NUM_CONFIG];
  	enum xgene_dma_ring_cfgsize cfgsize;
  	union {
  		void *desc_vaddr;
  		struct xgene_dma_desc_hw *desc_hw;
  	};
  };
  
  struct xgene_dma_desc_sw {
  	struct xgene_dma_desc_hw desc1;
  	struct xgene_dma_desc_hw desc2;
  	u32 flags;
  	struct list_head node;
  	struct list_head tx_list;
  	struct dma_async_tx_descriptor tx;
  };
  
  /**
   * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
   * @dma_chan: dmaengine channel object member
   * @pdma: X-Gene DMA device structure reference
   * @dev: struct device reference for dma mapping api
   * @id: raw id of this channel
   * @rx_irq: channel IRQ
   * @name: name of X-Gene DMA channel
   * @lock: serializes enqueue/dequeue operations to the descriptor pool
   * @pending: number of transaction request pushed to DMA controller for
   *	execution, but still waiting for completion,
   * @max_outstanding: max number of outstanding request we can push to channel
   * @ld_pending: descriptors which are queued to run, but have not yet been
   *	submitted to the hardware for execution
   * @ld_running: descriptors which are currently being executing by the hardware
   * @ld_completed: descriptors which have finished execution by the hardware.
   *	These descriptors have already had their cleanup actions run. They
   *	are waiting for the ACK bit to be set by the async tx API.
   * @desc_pool: descriptor pool for DMA operations
   * @tasklet: bottom half where all completed descriptors cleans
   * @tx_ring: transmit ring descriptor that we use to prepare actual
   *	descriptors for further executions
   * @rx_ring: receive ring descriptor that we use to get completed DMA
   *	descriptors during cleanup time
   */
  struct xgene_dma_chan {
  	struct dma_chan dma_chan;
  	struct xgene_dma *pdma;
  	struct device *dev;
  	int id;
  	int rx_irq;
  	char name[10];
  	spinlock_t lock;
  	int pending;
  	int max_outstanding;
  	struct list_head ld_pending;
  	struct list_head ld_running;
  	struct list_head ld_completed;
  	struct dma_pool *desc_pool;
  	struct tasklet_struct tasklet;
  	struct xgene_dma_ring tx_ring;
  	struct xgene_dma_ring rx_ring;
  };
  
  /**
   * struct xgene_dma - internal representation of an X-Gene DMA device
   * @dev: reference to this device's struct device
   * @clk: reference to this device's clock
   * @err_irq: DMA error irq number
   * @ring_num: start id number for DMA ring
   * @csr_dma: base for DMA register access
   * @csr_ring: base for DMA ring register access
   * @csr_ring_cmd: base for DMA ring command register access
   * @csr_efuse: base for efuse register access
   * @dma_dev: embedded struct dma_device
   * @chan: reference to X-Gene DMA channels
   */
  struct xgene_dma {
  	struct device *dev;
  	struct clk *clk;
  	int err_irq;
  	int ring_num;
  	void __iomem *csr_dma;
  	void __iomem *csr_ring;
  	void __iomem *csr_ring_cmd;
  	void __iomem *csr_efuse;
  	struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
  	struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
  };
  
  static const char * const xgene_dma_desc_err[] = {
  	[ERR_DESC_AXI] = "AXI error when reading src/dst link list",
  	[ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
  	[ERR_READ_DATA_AXI] = "AXI error when reading data",
  	[ERR_WRITE_DATA_AXI] = "AXI error when writing data",
  	[ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
  	[ERR_ECC] = "ECC double bit error",
  	[ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
  	[ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
  	[ERR_CRC_ERR] = "CRC error",
  	[ERR_CHKSUM] = "Checksum error",
  	[ERR_DIF] = "DIF error",
  };
  
  static const char * const xgene_dma_err[] = {
  	[ERR_DIF_SIZE_INT] = "DIF size error",
  	[ERR_GS_ERR_INT] = "Gather scatter not same size error",
  	[ERR_FPB_TIMEO_INT] = "Free pool time out error",
  	[ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
  	[ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
  	[ERR_WR_TIMEO_INT] = "Write time out error",
  	[ERR_RD_TIMEO_INT] = "Read time out error",
  	[ERR_WR_ERR_INT] = "HBF bus write error",
  	[ERR_RD_ERR_INT] = "HBF bus read error",
  	[ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
  	[ERR_DESC_DST_INT] = "HFB reading dst link address error",
  	[ERR_DESC_SRC_INT] = "HFB reading src link address error",
  };
  
  static bool is_pq_enabled(struct xgene_dma *pdma)
  {
  	u32 val;
  
  	val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
  	return !(val & XGENE_DMA_PQ_DISABLE_MASK);
  }
  
  static u64 xgene_dma_encode_len(size_t len)
  {
  	return (len < XGENE_DMA_MAX_BYTE_CNT) ?
  		((u64)len << XGENE_DMA_DESC_BUFLEN_POS) :
  		XGENE_DMA_16K_BUFFER_LEN_CODE;
  }
  
  static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
  {
  	static u8 flyby_type[] = {
  		FLYBY_2SRC_XOR, /* Dummy */
  		FLYBY_2SRC_XOR, /* Dummy */
  		FLYBY_2SRC_XOR,
  		FLYBY_3SRC_XOR,
  		FLYBY_4SRC_XOR,
  		FLYBY_5SRC_XOR
  	};
  
  	return flyby_type[src_cnt];
  }
  
  static void xgene_dma_set_src_buffer(__le64 *ext8, size_t *len,
  				     dma_addr_t *paddr)
  {
  	size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
  			*len : XGENE_DMA_MAX_BYTE_CNT;
  
  	*ext8 |= cpu_to_le64(*paddr);
  	*ext8 |= cpu_to_le64(xgene_dma_encode_len(nbytes));
  	*len -= nbytes;
  	*paddr += nbytes;
  }
  
  static __le64 *xgene_dma_lookup_ext8(struct xgene_dma_desc_hw *desc, int idx)
  {
  	switch (idx) {
  	case 0:
  		return &desc->m1;
  	case 1:
  		return &desc->m0;
  	case 2:
  		return &desc->m3;
  	case 3:
  		return &desc->m2;
  	default:
  		pr_err("Invalid dma descriptor index\n");
  	}
  
  	return NULL;
  }
  
  static void xgene_dma_init_desc(struct xgene_dma_desc_hw *desc,
  				u16 dst_ring_num)
  {
  	desc->m0 |= cpu_to_le64(XGENE_DMA_DESC_IN_BIT);
  	desc->m0 |= cpu_to_le64((u64)XGENE_DMA_RING_OWNER_DMA <<
  				XGENE_DMA_DESC_RTYPE_POS);
  	desc->m1 |= cpu_to_le64(XGENE_DMA_DESC_C_BIT);
  	desc->m3 |= cpu_to_le64((u64)dst_ring_num <<
  				XGENE_DMA_DESC_HOENQ_NUM_POS);
  }
  
  static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
  				    struct xgene_dma_desc_sw *desc_sw,
  				    dma_addr_t *dst, dma_addr_t *src,
  				    u32 src_cnt, size_t *nbytes,
  				    const u8 *scf)
  {
  	struct xgene_dma_desc_hw *desc1, *desc2;
  	size_t len = *nbytes;
  	int i;
  
  	desc1 = &desc_sw->desc1;
  	desc2 = &desc_sw->desc2;
  
  	/* Initialize DMA descriptor */
  	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
  
  	/* Set destination address */
  	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
  	desc1->m3 |= cpu_to_le64(*dst);
  
  	/* We have multiple source addresses, so need to set NV bit*/
  	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
  
  	/* Set flyby opcode */
  	desc1->m2 |= cpu_to_le64(xgene_dma_encode_xor_flyby(src_cnt));
  
  	/* Set 1st to 5th source addresses */
  	for (i = 0; i < src_cnt; i++) {
  		len = *nbytes;
  		xgene_dma_set_src_buffer((i == 0) ? &desc1->m1 :
  					 xgene_dma_lookup_ext8(desc2, i - 1),
  					 &len, &src[i]);
  		desc1->m2 |= cpu_to_le64((scf[i] << ((i + 1) * 8)));
  	}
  
  	/* Update meta data */
  	*nbytes = len;
  	*dst += XGENE_DMA_MAX_BYTE_CNT;
  
  	/* We need always 64B descriptor to perform xor or pq operations */
  	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
  }
  
  static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
  {
  	struct xgene_dma_desc_sw *desc;
  	struct xgene_dma_chan *chan;
  	dma_cookie_t cookie;
  
  	if (unlikely(!tx))
  		return -EINVAL;
  
  	chan = to_dma_chan(tx->chan);
  	desc = to_dma_desc_sw(tx);
  
  	spin_lock_bh(&chan->lock);
  
  	cookie = dma_cookie_assign(tx);
  
  	/* Add this transaction list onto the tail of the pending queue */
  	list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
  
  	spin_unlock_bh(&chan->lock);
  
  	return cookie;
  }
  
  static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
  				       struct xgene_dma_desc_sw *desc)
  {
  	list_del(&desc->node);
  	chan_dbg(chan, "LD %p free\n", desc);
  	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
  }
  
  static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
  				 struct xgene_dma_chan *chan)
  {
  	struct xgene_dma_desc_sw *desc;
  	dma_addr_t phys;
  
  	desc = dma_pool_zalloc(chan->desc_pool, GFP_NOWAIT, &phys);
  	if (!desc) {
  		chan_err(chan, "Failed to allocate LDs\n");
  		return NULL;
  	}
  
  	INIT_LIST_HEAD(&desc->tx_list);
  	desc->tx.phys = phys;
  	desc->tx.tx_submit = xgene_dma_tx_submit;
  	dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
  
  	chan_dbg(chan, "LD %p allocated\n", desc);
  
  	return desc;
  }
  
  /**
   * xgene_dma_clean_completed_descriptor - free all descriptors which
   * has been completed and acked
   * @chan: X-Gene DMA channel
   *
   * This function is used on all completed and acked descriptors.
   */
  static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
  {
  	struct xgene_dma_desc_sw *desc, *_desc;
  
  	/* Run the callback for each descriptor, in order */
  	list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
  		if (async_tx_test_ack(&desc->tx))
  			xgene_dma_clean_descriptor(chan, desc);
  	}
  }
  
  /**
   * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
   * @chan: X-Gene DMA channel
   * @desc: descriptor to cleanup and free
   *
   * This function is used on a descriptor which has been executed by the DMA
   * controller. It will run any callbacks, submit any dependencies.
   */
  static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
  					      struct xgene_dma_desc_sw *desc)
  {
  	struct dma_async_tx_descriptor *tx = &desc->tx;
  
  	/*
  	 * If this is not the last transaction in the group,
  	 * then no need to complete cookie and run any callback as
  	 * this is not the tx_descriptor which had been sent to caller
  	 * of this DMA request
  	 */
  
  	if (tx->cookie == 0)
  		return;
  
  	dma_cookie_complete(tx);
  	dma_descriptor_unmap(tx);
  
  	/* Run the link descriptor callback function */
  	dmaengine_desc_get_callback_invoke(tx, NULL);
  
  	/* Run any dependencies */
  	dma_run_dependencies(tx);
  }
  
  /**
   * xgene_dma_clean_running_descriptor - move the completed descriptor from
   * ld_running to ld_completed
   * @chan: X-Gene DMA channel
   * @desc: the descriptor which is completed
   *
   * Free the descriptor directly if acked by async_tx api,
   * else move it to queue ld_completed.
   */
  static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
  					       struct xgene_dma_desc_sw *desc)
  {
  	/* Remove from the list of running transactions */
  	list_del(&desc->node);
  
  	/*
  	 * the client is allowed to attach dependent operations
  	 * until 'ack' is set
  	 */
  	if (!async_tx_test_ack(&desc->tx)) {
  		/*
  		 * Move this descriptor to the list of descriptors which is
  		 * completed, but still awaiting the 'ack' bit to be set.
  		 */
  		list_add_tail(&desc->node, &chan->ld_completed);
  		return;
  	}
  
  	chan_dbg(chan, "LD %p free\n", desc);
  	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
  }
  
  static void xgene_chan_xfer_request(struct xgene_dma_chan *chan,
  				    struct xgene_dma_desc_sw *desc_sw)
  {
  	struct xgene_dma_ring *ring = &chan->tx_ring;
  	struct xgene_dma_desc_hw *desc_hw;
  
  	/* Get hw descriptor from DMA tx ring */
  	desc_hw = &ring->desc_hw[ring->head];
  
  	/*
  	 * Increment the head count to point next
  	 * descriptor for next time
  	 */
  	if (++ring->head == ring->slots)
  		ring->head = 0;
  
  	/* Copy prepared sw descriptor data to hw descriptor */
  	memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
  
  	/*
  	 * Check if we have prepared 64B descriptor,
  	 * in this case we need one more hw descriptor
  	 */
  	if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
  		desc_hw = &ring->desc_hw[ring->head];
  
  		if (++ring->head == ring->slots)
  			ring->head = 0;
  
  		memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
  	}
  
  	/* Increment the pending transaction count */
  	chan->pending += ((desc_sw->flags &
  			  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
  
  	/* Notify the hw that we have descriptor ready for execution */
  	iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
  		  2 : 1, ring->cmd);
  }
  
  /**
   * xgene_chan_xfer_ld_pending - push any pending transactions to hw
   * @chan : X-Gene DMA channel
   *
   * LOCKING: must hold chan->lock
   */
  static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
  {
  	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
  
  	/*
  	 * If the list of pending descriptors is empty, then we
  	 * don't need to do any work at all
  	 */
  	if (list_empty(&chan->ld_pending)) {
  		chan_dbg(chan, "No pending LDs\n");
  		return;
  	}
  
  	/*
  	 * Move elements from the queue of pending transactions onto the list
  	 * of running transactions and push it to hw for further executions
  	 */
  	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
  		/*
  		 * Check if have pushed max number of transactions to hw
  		 * as capable, so let's stop here and will push remaining
  		 * elements from pening ld queue after completing some
  		 * descriptors that we have already pushed
  		 */
  		if (chan->pending >= chan->max_outstanding)
  			return;
  
  		xgene_chan_xfer_request(chan, desc_sw);
  
  		/*
  		 * Delete this element from ld pending queue and append it to
  		 * ld running queue
  		 */
  		list_move_tail(&desc_sw->node, &chan->ld_running);
  	}
  }
  
  /**
   * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
   * and move them to ld_completed to free until flag 'ack' is set
   * @chan: X-Gene DMA channel
   *
   * This function is used on descriptors which have been executed by the DMA
   * controller. It will run any callbacks, submit any dependencies, then
   * free these descriptors if flag 'ack' is set.
   */
  static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
  {
  	struct xgene_dma_ring *ring = &chan->rx_ring;
  	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
  	struct xgene_dma_desc_hw *desc_hw;
  	struct list_head ld_completed;
  	u8 status;
  
  	INIT_LIST_HEAD(&ld_completed);
  
  	spin_lock(&chan->lock);
  
  	/* Clean already completed and acked descriptors */
  	xgene_dma_clean_completed_descriptor(chan);
  
  	/* Move all completed descriptors to ld completed queue, in order */
  	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
  		/* Get subsequent hw descriptor from DMA rx ring */
  		desc_hw = &ring->desc_hw[ring->head];
  
  		/* Check if this descriptor has been completed */
  		if (unlikely(le64_to_cpu(desc_hw->m0) ==
  			     XGENE_DMA_DESC_EMPTY_SIGNATURE))
  			break;
  
  		if (++ring->head == ring->slots)
  			ring->head = 0;
  
  		/* Check if we have any error with DMA transactions */
  		status = XGENE_DMA_DESC_STATUS(
  				XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
  							desc_hw->m0)),
  				XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
  						       desc_hw->m0)));
  		if (status) {
  			/* Print the DMA error type */
  			chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
  
  			/*
  			 * We have DMA transactions error here. Dump DMA Tx
  			 * and Rx descriptors for this request */
  			XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
  					    "X-Gene DMA TX DESC1: ");
  
  			if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
  				XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
  						    "X-Gene DMA TX DESC2: ");
  
  			XGENE_DMA_DESC_DUMP(desc_hw,
  					    "X-Gene DMA RX ERR DESC: ");
  		}
  
  		/* Notify the hw about this completed descriptor */
  		iowrite32(-1, ring->cmd);
  
  		/* Mark this hw descriptor as processed */
  		desc_hw->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
  
  		/*
  		 * Decrement the pending transaction count
  		 * as we have processed one
  		 */
  		chan->pending -= ((desc_sw->flags &
  				  XGENE_DMA_FLAG_64B_DESC) ? 2 : 1);
  
  		/*
  		 * Delete this node from ld running queue and append it to
  		 * ld completed queue for further processing
  		 */
  		list_move_tail(&desc_sw->node, &ld_completed);
  	}
  
  	/*
  	 * Start any pending transactions automatically
  	 * In the ideal case, we keep the DMA controller busy while we go
  	 * ahead and free the descriptors below.
  	 */
  	xgene_chan_xfer_ld_pending(chan);
  
  	spin_unlock(&chan->lock);
  
  	/* Run the callback for each descriptor, in order */
  	list_for_each_entry_safe(desc_sw, _desc_sw, &ld_completed, node) {
  		xgene_dma_run_tx_complete_actions(chan, desc_sw);
  		xgene_dma_clean_running_descriptor(chan, desc_sw);
  	}
  }
  
  static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
  {
  	struct xgene_dma_chan *chan = to_dma_chan(dchan);
  
  	/* Has this channel already been allocated? */
  	if (chan->desc_pool)
  		return 1;
  
  	chan->desc_pool = dma_pool_create(chan->name, chan->dev,
  					  sizeof(struct xgene_dma_desc_sw),
  					  0, 0);
  	if (!chan->desc_pool) {
  		chan_err(chan, "Failed to allocate descriptor pool\n");
  		return -ENOMEM;
  	}
  
  	chan_dbg(chan, "Allocate descriptor pool\n");
  
  	return 1;
  }
  
  /**
   * xgene_dma_free_desc_list - Free all descriptors in a queue
   * @chan: X-Gene DMA channel
   * @list: the list to free
   *
   * LOCKING: must hold chan->lock
   */
  static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
  				     struct list_head *list)
  {
  	struct xgene_dma_desc_sw *desc, *_desc;
  
  	list_for_each_entry_safe(desc, _desc, list, node)
  		xgene_dma_clean_descriptor(chan, desc);
  }
  
  static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
  {
  	struct xgene_dma_chan *chan = to_dma_chan(dchan);
  
  	chan_dbg(chan, "Free all resources\n");
  
  	if (!chan->desc_pool)
  		return;
  
  	/* Process all running descriptor */
  	xgene_dma_cleanup_descriptors(chan);
  
  	spin_lock_bh(&chan->lock);
  
  	/* Clean all link descriptor queues */
  	xgene_dma_free_desc_list(chan, &chan->ld_pending);
  	xgene_dma_free_desc_list(chan, &chan->ld_running);
  	xgene_dma_free_desc_list(chan, &chan->ld_completed);
  
  	spin_unlock_bh(&chan->lock);
  
  	/* Delete this channel DMA pool */
  	dma_pool_destroy(chan->desc_pool);
  	chan->desc_pool = NULL;
  }
  
  static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
  	struct dma_chan *dchan, dma_addr_t dst,	dma_addr_t *src,
  	u32 src_cnt, size_t len, unsigned long flags)
  {
  	struct xgene_dma_desc_sw *first = NULL, *new;
  	struct xgene_dma_chan *chan;
  	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
  				0x01, 0x01, 0x01, 0x01, 0x01};
  
  	if (unlikely(!dchan || !len))
  		return NULL;
  
  	chan = to_dma_chan(dchan);
  
  	do {
  		/* Allocate the link descriptor from DMA pool */
  		new = xgene_dma_alloc_descriptor(chan);
  		if (!new)
  			goto fail;
  
  		/* Prepare xor DMA descriptor */
  		xgene_dma_prep_xor_desc(chan, new, &dst, src,
  					src_cnt, &len, multi);
  
  		if (!first)
  			first = new;
  
  		new->tx.cookie = 0;
  		async_tx_ack(&new->tx);
  
  		/* Insert the link descriptor to the LD ring */
  		list_add_tail(&new->node, &first->tx_list);
  	} while (len);
  
  	new->tx.flags = flags; /* client is in control of this ack */
  	new->tx.cookie = -EBUSY;
  	list_splice(&first->tx_list, &new->tx_list);
  
  	return &new->tx;
  
  fail:
  	if (!first)
  		return NULL;
  
  	xgene_dma_free_desc_list(chan, &first->tx_list);
  	return NULL;
  }
  
  static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
  	struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
  	u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
  {
  	struct xgene_dma_desc_sw *first = NULL, *new;
  	struct xgene_dma_chan *chan;
  	size_t _len = len;
  	dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
  	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
  
  	if (unlikely(!dchan || !len))
  		return NULL;
  
  	chan = to_dma_chan(dchan);
  
  	/*
  	 * Save source addresses on local variable, may be we have to
  	 * prepare two descriptor to generate P and Q if both enabled
  	 * in the flags by client
  	 */
  	memcpy(_src, src, sizeof(*src) * src_cnt);
  
  	if (flags & DMA_PREP_PQ_DISABLE_P)
  		len = 0;
  
  	if (flags & DMA_PREP_PQ_DISABLE_Q)
  		_len = 0;
  
  	do {
  		/* Allocate the link descriptor from DMA pool */
  		new = xgene_dma_alloc_descriptor(chan);
  		if (!new)
  			goto fail;
  
  		if (!first)
  			first = new;
  
  		new->tx.cookie = 0;
  		async_tx_ack(&new->tx);
  
  		/* Insert the link descriptor to the LD ring */
  		list_add_tail(&new->node, &first->tx_list);
  
  		/*
  		 * Prepare DMA descriptor to generate P,
  		 * if DMA_PREP_PQ_DISABLE_P flag is not set
  		 */
  		if (len) {
  			xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
  						src_cnt, &len, multi);
  			continue;
  		}
  
  		/*
  		 * Prepare DMA descriptor to generate Q,
  		 * if DMA_PREP_PQ_DISABLE_Q flag is not set
  		 */
  		if (_len) {
  			xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
  						src_cnt, &_len, scf);
  		}
  	} while (len || _len);
  
  	new->tx.flags = flags; /* client is in control of this ack */
  	new->tx.cookie = -EBUSY;
  	list_splice(&first->tx_list, &new->tx_list);
  
  	return &new->tx;
  
  fail:
  	if (!first)
  		return NULL;
  
  	xgene_dma_free_desc_list(chan, &first->tx_list);
  	return NULL;
  }
  
  static void xgene_dma_issue_pending(struct dma_chan *dchan)
  {
  	struct xgene_dma_chan *chan = to_dma_chan(dchan);
  
  	spin_lock_bh(&chan->lock);
  	xgene_chan_xfer_ld_pending(chan);
  	spin_unlock_bh(&chan->lock);
  }
  
  static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
  					   dma_cookie_t cookie,
  					   struct dma_tx_state *txstate)
  {
  	return dma_cookie_status(dchan, cookie, txstate);
  }
  
  static void xgene_dma_tasklet_cb(struct tasklet_struct *t)
  {
  	struct xgene_dma_chan *chan = from_tasklet(chan, t, tasklet);
  
  	/* Run all cleanup for descriptors which have been completed */
  	xgene_dma_cleanup_descriptors(chan);
  
  	/* Re-enable DMA channel IRQ */
  	enable_irq(chan->rx_irq);
  }
  
  static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
  {
  	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
  
  	BUG_ON(!chan);
  
  	/*
  	 * Disable DMA channel IRQ until we process completed
  	 * descriptors
  	 */
  	disable_irq_nosync(chan->rx_irq);
  
  	/*
  	 * Schedule the tasklet to handle all cleanup of the current
  	 * transaction. It will start a new transaction if there is
  	 * one pending.
  	 */
  	tasklet_schedule(&chan->tasklet);
  
  	return IRQ_HANDLED;
  }
  
  static irqreturn_t xgene_dma_err_isr(int irq, void *id)
  {
  	struct xgene_dma *pdma = (struct xgene_dma *)id;
  	unsigned long int_mask;
  	u32 val, i;
  
  	val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
  
  	/* Clear DMA interrupts */
  	iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
  
  	/* Print DMA error info */
  	int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
  	for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
  		dev_err(pdma->dev,
  			"Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
  
  	return IRQ_HANDLED;
  }
  
  static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
  {
  	int i;
  
  	iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
  
  	for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
  		iowrite32(ring->state[i], ring->pdma->csr_ring +
  			  XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
  }
  
  static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
  {
  	memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
  	xgene_dma_wr_ring_state(ring);
  }
  
  static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
  {
  	void *ring_cfg = ring->state;
  	u64 addr = ring->desc_paddr;
  	u32 i, val;
  
  	ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
  
  	/* Clear DMA ring state */
  	xgene_dma_clr_ring_state(ring);
  
  	/* Set DMA ring type */
  	XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
  
  	if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
  		/* Set recombination buffer and timeout */
  		XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
  		XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
  		XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
  	}
  
  	/* Initialize DMA ring state */
  	XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
  	XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
  	XGENE_DMA_RING_COHERENT_SET(ring_cfg);
  	XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
  	XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
  	XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
  
  	/* Write DMA ring configurations */
  	xgene_dma_wr_ring_state(ring);
  
  	/* Set DMA ring id */
  	iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
  		  ring->pdma->csr_ring + XGENE_DMA_RING_ID);
  
  	/* Set DMA ring buffer */
  	iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
  		  ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
  
  	if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
  		return;
  
  	/* Set empty signature to DMA Rx ring descriptors */
  	for (i = 0; i < ring->slots; i++) {
  		struct xgene_dma_desc_hw *desc;
  
  		desc = &ring->desc_hw[i];
  		desc->m0 = cpu_to_le64(XGENE_DMA_DESC_EMPTY_SIGNATURE);
  	}
  
  	/* Enable DMA Rx ring interrupt */
  	val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
  	XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
  	iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
  }
  
  static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
  {
  	u32 ring_id, val;
  
  	if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
  		/* Disable DMA Rx ring interrupt */
  		val = ioread32(ring->pdma->csr_ring +
  			       XGENE_DMA_RING_NE_INT_MODE);
  		XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
  		iowrite32(val, ring->pdma->csr_ring +
  			  XGENE_DMA_RING_NE_INT_MODE);
  	}
  
  	/* Clear DMA ring state */
  	ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
  	iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
  
  	iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
  	xgene_dma_clr_ring_state(ring);
  }
  
  static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
  {
  	ring->cmd_base = ring->pdma->csr_ring_cmd +
  				XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
  							  XGENE_DMA_RING_NUM));
  
  	ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
  }
  
  static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
  				   enum xgene_dma_ring_cfgsize cfgsize)
  {
  	int size;
  
  	switch (cfgsize) {
  	case XGENE_DMA_RING_CFG_SIZE_512B:
  		size = 0x200;
  		break;
  	case XGENE_DMA_RING_CFG_SIZE_2KB:
  		size = 0x800;
  		break;
  	case XGENE_DMA_RING_CFG_SIZE_16KB:
  		size = 0x4000;
  		break;
  	case XGENE_DMA_RING_CFG_SIZE_64KB:
  		size = 0x10000;
  		break;
  	case XGENE_DMA_RING_CFG_SIZE_512KB:
  		size = 0x80000;
  		break;
  	default:
  		chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
  		return -EINVAL;
  	}
  
  	return size;
  }
  
  static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
  {
  	/* Clear DMA ring configurations */
  	xgene_dma_clear_ring(ring);
  
  	/* De-allocate DMA ring descriptor */
  	if (ring->desc_vaddr) {
  		dma_free_coherent(ring->pdma->dev, ring->size,
  				  ring->desc_vaddr, ring->desc_paddr);
  		ring->desc_vaddr = NULL;
  	}
  }
  
  static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
  {
  	xgene_dma_delete_ring_one(&chan->rx_ring);
  	xgene_dma_delete_ring_one(&chan->tx_ring);
  }
  
  static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
  				     struct xgene_dma_ring *ring,
  				     enum xgene_dma_ring_cfgsize cfgsize)
  {
  	int ret;
  
  	/* Setup DMA ring descriptor variables */
  	ring->pdma = chan->pdma;
  	ring->cfgsize = cfgsize;
  	ring->num = chan->pdma->ring_num++;
  	ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
  
  	ret = xgene_dma_get_ring_size(chan, cfgsize);
  	if (ret <= 0)
  		return ret;
  	ring->size = ret;
  
  	/* Allocate memory for DMA ring descriptor */
  	ring->desc_vaddr = dma_alloc_coherent(chan->dev, ring->size,
  					      &ring->desc_paddr, GFP_KERNEL);
  	if (!ring->desc_vaddr) {
  		chan_err(chan, "Failed to allocate ring desc\n");
  		return -ENOMEM;
  	}
  
  	/* Configure and enable DMA ring */
  	xgene_dma_set_ring_cmd(ring);
  	xgene_dma_setup_ring(ring);
  
  	return 0;
  }
  
  static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
  {
  	struct xgene_dma_ring *rx_ring = &chan->rx_ring;
  	struct xgene_dma_ring *tx_ring = &chan->tx_ring;
  	int ret;
  
  	/* Create DMA Rx ring descriptor */
  	rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
  	rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
  
  	ret = xgene_dma_create_ring_one(chan, rx_ring,
  					XGENE_DMA_RING_CFG_SIZE_64KB);
  	if (ret)
  		return ret;
  
  	chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
  		 rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
  
  	/* Create DMA Tx ring descriptor */
  	tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
  	tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
  
  	ret = xgene_dma_create_ring_one(chan, tx_ring,
  					XGENE_DMA_RING_CFG_SIZE_64KB);
  	if (ret) {
  		xgene_dma_delete_ring_one(rx_ring);
  		return ret;
  	}
  
  	tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
  
  	chan_dbg(chan,
  		 "Tx ring id 0x%X num %d desc 0x%p\n",
  		 tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
  
  	/* Set the max outstanding request possible to this channel */
  	chan->max_outstanding = tx_ring->slots;
  
  	return ret;
  }
  
  static int xgene_dma_init_rings(struct xgene_dma *pdma)
  {
  	int ret, i, j;
  
  	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
  		ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
  		if (ret) {
  			for (j = 0; j < i; j++)
  				xgene_dma_delete_chan_rings(&pdma->chan[j]);
  			return ret;
  		}
  	}
  
  	return ret;
  }
  
  static void xgene_dma_enable(struct xgene_dma *pdma)
  {
  	u32 val;
  
  	/* Configure and enable DMA engine */
  	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
  	XGENE_DMA_CH_SETUP(val);
  	XGENE_DMA_ENABLE(val);
  	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
  }
  
  static void xgene_dma_disable(struct xgene_dma *pdma)
  {
  	u32 val;
  
  	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
  	XGENE_DMA_DISABLE(val);
  	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
  }
  
  static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
  {
  	/*
  	 * Mask DMA ring overflow, underflow and
  	 * AXI write/read error interrupts
  	 */
  	iowrite32(XGENE_DMA_INT_ALL_MASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
  	iowrite32(XGENE_DMA_INT_ALL_MASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
  	iowrite32(XGENE_DMA_INT_ALL_MASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
  	iowrite32(XGENE_DMA_INT_ALL_MASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
  	iowrite32(XGENE_DMA_INT_ALL_MASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
  
  	/* Mask DMA error interrupts */
  	iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
  }
  
  static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
  {
  	/*
  	 * Unmask DMA ring overflow, underflow and
  	 * AXI write/read error interrupts
  	 */
  	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
  	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
  	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
  	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
  	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
  		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
  
  	/* Unmask DMA error interrupts */
  	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
  		  pdma->csr_dma + XGENE_DMA_INT_MASK);
  }
  
  static void xgene_dma_init_hw(struct xgene_dma *pdma)
  {
  	u32 val;
  
  	/* Associate DMA ring to corresponding ring HW */
  	iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
  		  pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
  
  	/* Configure RAID6 polynomial control setting */
  	if (is_pq_enabled(pdma))
  		iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
  			  pdma->csr_dma + XGENE_DMA_RAID6_CONT);
  	else
  		dev_info(pdma->dev, "PQ is disabled in HW\n");
  
  	xgene_dma_enable(pdma);
  	xgene_dma_unmask_interrupts(pdma);
  
  	/* Get DMA id and version info */
  	val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
  
  	/* DMA device info */
  	dev_info(pdma->dev,
  		 "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
  		 XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
  		 XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
  }
  
  static int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
  {
  	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
  	    (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
  		return 0;
  
  	iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
  	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
  
  	/* Bring up memory */
  	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
  
  	/* Force a barrier */
  	ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
  
  	/* reset may take up to 1ms */
  	usleep_range(1000, 1100);
  
  	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
  		!= XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
  		dev_err(pdma->dev,
  			"Failed to release ring mngr memory from shutdown\n");
  		return -ENODEV;
  	}
  
  	/* program threshold set 1 and all hysteresis */
  	iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
  		  pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
  	iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
  		  pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
  	iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
  		  pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
  
  	/* Enable QPcore and assign error queue */
  	iowrite32(XGENE_DMA_RING_ENABLE,
  		  pdma->csr_ring + XGENE_DMA_RING_CONFIG);
  
  	return 0;
  }
  
  static int xgene_dma_init_mem(struct xgene_dma *pdma)
  {
  	int ret;
  
  	ret = xgene_dma_init_ring_mngr(pdma);
  	if (ret)
  		return ret;
  
  	/* Bring up memory */
  	iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
  
  	/* Force a barrier */
  	ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
  
  	/* reset may take up to 1ms */
  	usleep_range(1000, 1100);
  
  	if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
  		!= XGENE_DMA_BLK_MEM_RDY_VAL) {
  		dev_err(pdma->dev,
  			"Failed to release DMA memory from shutdown\n");
  		return -ENODEV;
  	}
  
  	return 0;
  }
  
  static int xgene_dma_request_irqs(struct xgene_dma *pdma)
  {
  	struct xgene_dma_chan *chan;
  	int ret, i, j;
  
  	/* Register DMA error irq */
  	ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
  			       0, "dma_error", pdma);
  	if (ret) {
  		dev_err(pdma->dev,
  			"Failed to register error IRQ %d\n", pdma->err_irq);
  		return ret;
  	}
  
  	/* Register DMA channel rx irq */
  	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
  		chan = &pdma->chan[i];
  		irq_set_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
  		ret = devm_request_irq(chan->dev, chan->rx_irq,
  				       xgene_dma_chan_ring_isr,
  				       0, chan->name, chan);
  		if (ret) {
  			chan_err(chan, "Failed to register Rx IRQ %d\n",
  				 chan->rx_irq);
  			devm_free_irq(pdma->dev, pdma->err_irq, pdma);
  
  			for (j = 0; j < i; j++) {
  				chan = &pdma->chan[i];
  				irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
  				devm_free_irq(chan->dev, chan->rx_irq, chan);
  			}
  
  			return ret;
  		}
  	}
  
  	return 0;
  }
  
  static void xgene_dma_free_irqs(struct xgene_dma *pdma)
  {
  	struct xgene_dma_chan *chan;
  	int i;
  
  	/* Free DMA device error irq */
  	devm_free_irq(pdma->dev, pdma->err_irq, pdma);
  
  	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
  		chan = &pdma->chan[i];
  		irq_clear_status_flags(chan->rx_irq, IRQ_DISABLE_UNLAZY);
  		devm_free_irq(chan->dev, chan->rx_irq, chan);
  	}
  }
  
  static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
  			       struct dma_device *dma_dev)
  {
  	/* Initialize DMA device capability mask */
  	dma_cap_zero(dma_dev->cap_mask);
  
  	/* Set DMA device capability */
  
  	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
  	 * and channel 1 supports XOR, PQ both. First thing here is we have
  	 * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
  	 * we can make sure this by reading SoC Efuse register.
  	 * Second thing, we have hw errata that if we run channel 0 and
  	 * channel 1 simultaneously with executing XOR and PQ request,
  	 * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
  	 * if XOR and PQ supports on channel 1 is disabled.
  	 */
  	if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
  	    is_pq_enabled(chan->pdma)) {
  		dma_cap_set(DMA_PQ, dma_dev->cap_mask);
  		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
  	} else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
  		   !is_pq_enabled(chan->pdma)) {
  		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
  	}
  
  	/* Set base and prep routines */
  	dma_dev->dev = chan->dev;
  	dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
  	dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
  	dma_dev->device_issue_pending = xgene_dma_issue_pending;
  	dma_dev->device_tx_status = xgene_dma_tx_status;
  
  	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
  		dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
  		dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
  		dma_dev->xor_align = DMAENGINE_ALIGN_64_BYTES;
  	}
  
  	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
  		dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
  		dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
  		dma_dev->pq_align = DMAENGINE_ALIGN_64_BYTES;
  	}
  }
  
  static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
  {
  	struct xgene_dma_chan *chan = &pdma->chan[id];
  	struct dma_device *dma_dev = &pdma->dma_dev[id];
  	int ret;
  
  	chan->dma_chan.device = dma_dev;
  
  	spin_lock_init(&chan->lock);
  	INIT_LIST_HEAD(&chan->ld_pending);
  	INIT_LIST_HEAD(&chan->ld_running);
  	INIT_LIST_HEAD(&chan->ld_completed);
  	tasklet_setup(&chan->tasklet, xgene_dma_tasklet_cb);
  
  	chan->pending = 0;
  	chan->desc_pool = NULL;
  	dma_cookie_init(&chan->dma_chan);
  
  	/* Setup dma device capabilities and prep routines */
  	xgene_dma_set_caps(chan, dma_dev);
  
  	/* Initialize DMA device list head */
  	INIT_LIST_HEAD(&dma_dev->channels);
  	list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
  
  	/* Register with Linux async DMA framework*/
  	ret = dma_async_device_register(dma_dev);
  	if (ret) {
  		chan_err(chan, "Failed to register async device %d", ret);
  		tasklet_kill(&chan->tasklet);
  
  		return ret;
  	}
  
  	/* DMA capability info */
  	dev_info(pdma->dev,
  		 "%s: CAPABILITY ( %s%s)\n", dma_chan_name(&chan->dma_chan),
  		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
  		 dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
  
  	return 0;
  }
  
  static int xgene_dma_init_async(struct xgene_dma *pdma)
  {
  	int ret, i, j;
  
  	for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
  		ret = xgene_dma_async_register(pdma, i);
  		if (ret) {
  			for (j = 0; j < i; j++) {
  				dma_async_device_unregister(&pdma->dma_dev[j]);
  				tasklet_kill(&pdma->chan[j].tasklet);
  			}
  
  			return ret;
  		}
  	}
  
  	return ret;
  }
  
  static void xgene_dma_async_unregister(struct xgene_dma *pdma)
  {
  	int i;
  
  	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
  		dma_async_device_unregister(&pdma->dma_dev[i]);
  }
  
  static void xgene_dma_init_channels(struct xgene_dma *pdma)
  {
  	struct xgene_dma_chan *chan;
  	int i;
  
  	pdma->ring_num = XGENE_DMA_RING_NUM;
  
  	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
  		chan = &pdma->chan[i];
  		chan->dev = pdma->dev;
  		chan->pdma = pdma;
  		chan->id = i;
  		snprintf(chan->name, sizeof(chan->name), "dmachan%d", chan->id);
  	}
  }
  
  static int xgene_dma_get_resources(struct platform_device *pdev,
  				   struct xgene_dma *pdma)
  {
  	struct resource *res;
  	int irq, i;
  
  	/* Get DMA csr region */
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res) {
  		dev_err(&pdev->dev, "Failed to get csr region\n");
  		return -ENXIO;
  	}
  
  	pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
  				     resource_size(res));
  	if (!pdma->csr_dma) {
  		dev_err(&pdev->dev, "Failed to ioremap csr region");
  		return -ENOMEM;
  	}
  
  	/* Get DMA ring csr region */
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
  	if (!res) {
  		dev_err(&pdev->dev, "Failed to get ring csr region\n");
  		return -ENXIO;
  	}
  
  	pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
  				       resource_size(res));
  	if (!pdma->csr_ring) {
  		dev_err(&pdev->dev, "Failed to ioremap ring csr region");
  		return -ENOMEM;
  	}
  
  	/* Get DMA ring cmd csr region */
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
  	if (!res) {
  		dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
  		return -ENXIO;
  	}
  
  	pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
  					  resource_size(res));
  	if (!pdma->csr_ring_cmd) {
  		dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
  		return -ENOMEM;
  	}
  
  	pdma->csr_ring_cmd += XGENE_DMA_RING_CMD_SM_OFFSET;
  
  	/* Get efuse csr region */
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
  	if (!res) {
  		dev_err(&pdev->dev, "Failed to get efuse csr region\n");
  		return -ENXIO;
  	}
  
  	pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
  				       resource_size(res));
  	if (!pdma->csr_efuse) {
  		dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
  		return -ENOMEM;
  	}
  
  	/* Get DMA error interrupt */
  	irq = platform_get_irq(pdev, 0);
  	if (irq <= 0)
  		return -ENXIO;
  
  	pdma->err_irq = irq;
  
  	/* Get DMA Rx ring descriptor interrupts for all DMA channels */
  	for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
  		irq = platform_get_irq(pdev, i);
  		if (irq <= 0)
  			return -ENXIO;
  
  		pdma->chan[i - 1].rx_irq = irq;
  	}
  
  	return 0;
  }
  
  static int xgene_dma_probe(struct platform_device *pdev)
  {
  	struct xgene_dma *pdma;
  	int ret, i;
  
  	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
  	if (!pdma)
  		return -ENOMEM;
  
  	pdma->dev = &pdev->dev;
  	platform_set_drvdata(pdev, pdma);
  
  	ret = xgene_dma_get_resources(pdev, pdma);
  	if (ret)
  		return ret;
  
  	pdma->clk = devm_clk_get(&pdev->dev, NULL);
  	if (IS_ERR(pdma->clk) && !ACPI_COMPANION(&pdev->dev)) {
  		dev_err(&pdev->dev, "Failed to get clk\n");
  		return PTR_ERR(pdma->clk);
  	}
  
  	/* Enable clk before accessing registers */
  	if (!IS_ERR(pdma->clk)) {
  		ret = clk_prepare_enable(pdma->clk);
  		if (ret) {
  			dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
  			return ret;
  		}
  	}
  
  	/* Remove DMA RAM out of shutdown */
  	ret = xgene_dma_init_mem(pdma);
  	if (ret)
  		goto err_clk_enable;
  
  	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
  	if (ret) {
  		dev_err(&pdev->dev, "No usable DMA configuration\n");
  		goto err_dma_mask;
  	}
  
  	/* Initialize DMA channels software state */
  	xgene_dma_init_channels(pdma);
  
  	/* Configue DMA rings */
  	ret = xgene_dma_init_rings(pdma);
  	if (ret)
  		goto err_clk_enable;
  
  	ret = xgene_dma_request_irqs(pdma);
  	if (ret)
  		goto err_request_irq;
  
  	/* Configure and enable DMA engine */
  	xgene_dma_init_hw(pdma);
  
  	/* Register DMA device with linux async framework */
  	ret = xgene_dma_init_async(pdma);
  	if (ret)
  		goto err_async_init;
  
  	return 0;
  
  err_async_init:
  	xgene_dma_free_irqs(pdma);
  
  err_request_irq:
  	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
  		xgene_dma_delete_chan_rings(&pdma->chan[i]);
  
  err_dma_mask:
  err_clk_enable:
  	if (!IS_ERR(pdma->clk))
  		clk_disable_unprepare(pdma->clk);
  
  	return ret;
  }
  
  static int xgene_dma_remove(struct platform_device *pdev)
  {
  	struct xgene_dma *pdma = platform_get_drvdata(pdev);
  	struct xgene_dma_chan *chan;
  	int i;
  
  	xgene_dma_async_unregister(pdma);
  
  	/* Mask interrupts and disable DMA engine */
  	xgene_dma_mask_interrupts(pdma);
  	xgene_dma_disable(pdma);
  	xgene_dma_free_irqs(pdma);
  
  	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
  		chan = &pdma->chan[i];
  		tasklet_kill(&chan->tasklet);
  		xgene_dma_delete_chan_rings(chan);
  	}
  
  	if (!IS_ERR(pdma->clk))
  		clk_disable_unprepare(pdma->clk);
  
  	return 0;
  }
  
  #ifdef CONFIG_ACPI
  static const struct acpi_device_id xgene_dma_acpi_match_ptr[] = {
  	{"APMC0D43", 0},
  	{},
  };
  MODULE_DEVICE_TABLE(acpi, xgene_dma_acpi_match_ptr);
  #endif
  
  static const struct of_device_id xgene_dma_of_match_ptr[] = {
  	{.compatible = "apm,xgene-storm-dma",},
  	{},
  };
  MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
  
  static struct platform_driver xgene_dma_driver = {
  	.probe = xgene_dma_probe,
  	.remove = xgene_dma_remove,
  	.driver = {
  		.name = "X-Gene-DMA",
  		.of_match_table = xgene_dma_of_match_ptr,
  		.acpi_match_table = ACPI_PTR(xgene_dma_acpi_match_ptr),
  	},
  };
  
  module_platform_driver(xgene_dma_driver);
  
  MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
  MODULE_AUTHOR("Rameshwar Prasad Sahu <rsahu@apm.com>");
  MODULE_AUTHOR("Loc Ho <lho@apm.com>");
  MODULE_LICENSE("GPL");
  MODULE_VERSION("1.0");
  