/*
   * Copyright 2014 Cisco Systems, Inc.  All rights reserved.
   *
   * This program is free software; you may redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; version 2 of the License.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/types.h>
  #include <linux/pci.h>
  #include <linux/delay.h>
  #include <linux/if_ether.h>
  #include <linux/slab.h>
  #include "vnic_resource.h"
  #include "vnic_devcmd.h"
  #include "vnic_dev.h"
  #include "vnic_stats.h"
  #include "vnic_wq.h"
  
  #define VNIC_DVCMD_TMO	10000	/* Devcmd Timeout value */
  #define VNIC_NOTIFY_INTR_MASK 0x0000ffff00000000ULL
  
  struct devcmd2_controller {
  	struct vnic_wq_ctrl __iomem *wq_ctrl;
  	struct vnic_dev_ring results_ring;
  	struct vnic_wq wq;
  	struct vnic_devcmd2 *cmd_ring;
  	struct devcmd2_result *result;
  	u16 next_result;
  	u16 result_size;
  	int color;
  };
  
  struct vnic_res {
  	void __iomem *vaddr;
  	unsigned int count;
  };
  
  struct vnic_dev {
  	void *priv;
  	struct pci_dev *pdev;
  	struct vnic_res res[RES_TYPE_MAX];
  	enum vnic_dev_intr_mode intr_mode;
  	struct vnic_devcmd __iomem *devcmd;
  	struct vnic_devcmd_notify *notify;
  	struct vnic_devcmd_notify notify_copy;
  	dma_addr_t notify_pa;
  	u32 *linkstatus;
  	dma_addr_t linkstatus_pa;
  	struct vnic_stats *stats;
  	dma_addr_t stats_pa;
  	struct vnic_devcmd_fw_info *fw_info;
  	dma_addr_t fw_info_pa;
  	u64 args[VNIC_DEVCMD_NARGS];
  	struct devcmd2_controller *devcmd2;
  
  	int (*devcmd_rtn)(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
  			  int wait);
  };
  
  #define VNIC_MAX_RES_HDR_SIZE \
  	(sizeof(struct vnic_resource_header) + \
  	sizeof(struct vnic_resource) * RES_TYPE_MAX)
  #define VNIC_RES_STRIDE	128
  
  void *svnic_dev_priv(struct vnic_dev *vdev)
  {
  	return vdev->priv;
  }
  
  static int vnic_dev_discover_res(struct vnic_dev *vdev,
  	struct vnic_dev_bar *bar, unsigned int num_bars)
  {
  	struct vnic_resource_header __iomem *rh;
  	struct vnic_resource __iomem *r;
  	u8 type;
  
  	if (num_bars == 0)
  		return -EINVAL;
  
  	if (bar->len < VNIC_MAX_RES_HDR_SIZE) {
  		pr_err("vNIC BAR0 res hdr length error
  ");
  
  		return -EINVAL;
  	}
  
  	rh = bar->vaddr;
  	if (!rh) {
  		pr_err("vNIC BAR0 res hdr not mem-mapped
  ");
  
  		return -EINVAL;
  	}
  
  	if (ioread32(&rh->magic) != VNIC_RES_MAGIC ||
  	    ioread32(&rh->version) != VNIC_RES_VERSION) {
  		pr_err("vNIC BAR0 res magic/version error exp (%lx/%lx) curr (%x/%x)
  ",
  			VNIC_RES_MAGIC, VNIC_RES_VERSION,
  			ioread32(&rh->magic), ioread32(&rh->version));
  
  		return -EINVAL;
  	}
  
  	r = (struct vnic_resource __iomem *)(rh + 1);
  
  	while ((type = ioread8(&r->type)) != RES_TYPE_EOL) {
  
  		u8 bar_num = ioread8(&r->bar);
  		u32 bar_offset = ioread32(&r->bar_offset);
  		u32 count = ioread32(&r->count);
  		u32 len;
  
  		r++;
  
  		if (bar_num >= num_bars)
  			continue;
  
  		if (!bar[bar_num].len || !bar[bar_num].vaddr)
  			continue;
  
  		switch (type) {
  		case RES_TYPE_WQ:
  		case RES_TYPE_RQ:
  		case RES_TYPE_CQ:
  		case RES_TYPE_INTR_CTRL:
  			/* each count is stride bytes long */
  			len = count * VNIC_RES_STRIDE;
  			if (len + bar_offset > bar->len) {
  				pr_err("vNIC BAR0 resource %d out-of-bounds, offset 0x%x + size 0x%x > bar len 0x%lx
  ",
  					type, bar_offset,
  					len,
  					bar->len);
  
  				return -EINVAL;
  			}
  			break;
  
  		case RES_TYPE_INTR_PBA_LEGACY:
  		case RES_TYPE_DEVCMD:
  		case RES_TYPE_DEVCMD2:
  			len = count;
  			break;
  
  		default:
  			continue;
  		}
  
  		vdev->res[type].count = count;
  		vdev->res[type].vaddr = (char __iomem *)bar->vaddr + bar_offset;
  	}
  
  	return 0;
  }
  
  unsigned int svnic_dev_get_res_count(struct vnic_dev *vdev,
  	enum vnic_res_type type)
  {
  	return vdev->res[type].count;
  }
  
  void __iomem *svnic_dev_get_res(struct vnic_dev *vdev, enum vnic_res_type type,
  	unsigned int index)
  {
  	if (!vdev->res[type].vaddr)
  		return NULL;
  
  	switch (type) {
  	case RES_TYPE_WQ:
  	case RES_TYPE_RQ:
  	case RES_TYPE_CQ:
  	case RES_TYPE_INTR_CTRL:
  		return (char __iomem *)vdev->res[type].vaddr +
  					index * VNIC_RES_STRIDE;
  
  	default:
  		return (char __iomem *)vdev->res[type].vaddr;
  	}
  }
  
  unsigned int svnic_dev_desc_ring_size(struct vnic_dev_ring *ring,
  				      unsigned int desc_count,
  				      unsigned int desc_size)
  {
  	/* The base address of the desc rings must be 512 byte aligned.
  	 * Descriptor count is aligned to groups of 32 descriptors.  A
  	 * count of 0 means the maximum 4096 descriptors.  Descriptor
  	 * size is aligned to 16 bytes.
  	 */
  
  	unsigned int count_align = 32;
  	unsigned int desc_align = 16;
  
  	ring->base_align = 512;
  
  	if (desc_count == 0)
  		desc_count = 4096;
  
  	ring->desc_count = ALIGN(desc_count, count_align);
  
  	ring->desc_size = ALIGN(desc_size, desc_align);
  
  	ring->size = ring->desc_count * ring->desc_size;
  	ring->size_unaligned = ring->size + ring->base_align;
  
  	return ring->size_unaligned;
  }
  
  void svnic_dev_clear_desc_ring(struct vnic_dev_ring *ring)
  {
  	memset(ring->descs, 0, ring->size);
  }
  
  int svnic_dev_alloc_desc_ring(struct vnic_dev *vdev, struct vnic_dev_ring *ring,
  	unsigned int desc_count, unsigned int desc_size)
  {
  	svnic_dev_desc_ring_size(ring, desc_count, desc_size);
  
  	ring->descs_unaligned = pci_alloc_consistent(vdev->pdev,
  		ring->size_unaligned,
  		&ring->base_addr_unaligned);
  
  	if (!ring->descs_unaligned) {
  		pr_err("Failed to allocate ring (size=%d), aborting
  ",
  			(int)ring->size);
  
  		return -ENOMEM;
  	}
  
  	ring->base_addr = ALIGN(ring->base_addr_unaligned,
  		ring->base_align);
  	ring->descs = (u8 *)ring->descs_unaligned +
  		(ring->base_addr - ring->base_addr_unaligned);
  
  	svnic_dev_clear_desc_ring(ring);
  
  	ring->desc_avail = ring->desc_count - 1;
  
  	return 0;
  }
  
  void svnic_dev_free_desc_ring(struct vnic_dev *vdev, struct vnic_dev_ring *ring)
  {
  	if (ring->descs) {
  		pci_free_consistent(vdev->pdev,
  			ring->size_unaligned,
  			ring->descs_unaligned,
  			ring->base_addr_unaligned);
  		ring->descs = NULL;
  	}
  }
  
  static int _svnic_dev_cmd2(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
  	int wait)
  {
  	struct devcmd2_controller *dc2c = vdev->devcmd2;
  	struct devcmd2_result *result = dc2c->result + dc2c->next_result;
  	unsigned int i;
  	int delay;
  	int err;
  	u32 posted;
  	u32 new_posted;
  
  	posted = ioread32(&dc2c->wq_ctrl->posted_index);
  
  	if (posted == 0xFFFFFFFF) { /* check for hardware gone  */
  		/* Hardware surprise removal: return error */
  		return -ENODEV;
  	}
  
  	new_posted = (posted + 1) % DEVCMD2_RING_SIZE;
  	dc2c->cmd_ring[posted].cmd = cmd;
  	dc2c->cmd_ring[posted].flags = 0;
  
  	if ((_CMD_FLAGS(cmd) & _CMD_FLAGS_NOWAIT))
  		dc2c->cmd_ring[posted].flags |= DEVCMD2_FNORESULT;
  
  	if (_CMD_DIR(cmd) & _CMD_DIR_WRITE) {
  		for (i = 0; i < VNIC_DEVCMD_NARGS; i++)
  			dc2c->cmd_ring[posted].args[i] = vdev->args[i];
  	}
  	/* Adding write memory barrier prevents compiler and/or CPU
  	 * reordering, thus avoiding descriptor posting before
  	 * descriptor is initialized. Otherwise, hardware can read
  	 * stale descriptor fields.
  	 */
  	wmb();
  	iowrite32(new_posted, &dc2c->wq_ctrl->posted_index);
  
  	if (dc2c->cmd_ring[posted].flags & DEVCMD2_FNORESULT)
  		return 0;
  
  	for (delay = 0; delay < wait; delay++) {
  		udelay(100);
  		if (result->color == dc2c->color) {
  			dc2c->next_result++;
  			if (dc2c->next_result == dc2c->result_size) {
  				dc2c->next_result = 0;
  				dc2c->color = dc2c->color ? 0 : 1;
  			}
  			if (result->error) {
  				err = (int) result->error;
  				if (err != ERR_ECMDUNKNOWN ||
  				    cmd != CMD_CAPABILITY)
  					pr_err("Error %d devcmd %d
  ",
  						err, _CMD_N(cmd));
  
  				return err;
  			}
  			if (_CMD_DIR(cmd) & _CMD_DIR_READ) {
  				/*
  				 * Adding the rmb() prevents the compiler
  				 * and/or CPU from reordering the reads which
  				 * would potentially result in reading stale
  				 * values.
  				 */
  				rmb();
  				for (i = 0; i < VNIC_DEVCMD_NARGS; i++)
  					vdev->args[i] = result->results[i];
  			}
  
  			return 0;
  		}
  	}
  
  	pr_err("Timed out devcmd %d
  ", _CMD_N(cmd));
  
  	return -ETIMEDOUT;
  }
  
  static int svnic_dev_init_devcmd2(struct vnic_dev *vdev)
  {
  	struct devcmd2_controller *dc2c = NULL;
  	unsigned int fetch_idx;
  	int ret;
  	void __iomem *p;
  
  	if (vdev->devcmd2)
  		return 0;
  
  	p = svnic_dev_get_res(vdev, RES_TYPE_DEVCMD2, 0);
  	if (!p)
  		return -ENODEV;
  
  	dc2c = kzalloc(sizeof(*dc2c), GFP_ATOMIC);
  	if (!dc2c)
  		return -ENOMEM;
  
  	vdev->devcmd2 = dc2c;
  
  	dc2c->color = 1;
  	dc2c->result_size = DEVCMD2_RING_SIZE;
  
  	ret  = vnic_wq_devcmd2_alloc(vdev,
  				     &dc2c->wq,
  				     DEVCMD2_RING_SIZE,
  				     DEVCMD2_DESC_SIZE);
  	if (ret)
  		goto err_free_devcmd2;
  
  	fetch_idx = ioread32(&dc2c->wq.ctrl->fetch_index);
  	if (fetch_idx == 0xFFFFFFFF) { /* check for hardware gone  */
  		/* Hardware surprise removal: reset fetch_index */
  		fetch_idx = 0;
  	}
  
  	/*
  	 * Don't change fetch_index ever and
  	 * set posted_index same as fetch_index
  	 * when setting up the WQ for devcmd2.
  	 */
  	vnic_wq_init_start(&dc2c->wq, 0, fetch_idx, fetch_idx, 0, 0);
  	svnic_wq_enable(&dc2c->wq);
  	ret = svnic_dev_alloc_desc_ring(vdev,
  					&dc2c->results_ring,
  					DEVCMD2_RING_SIZE,
  					DEVCMD2_DESC_SIZE);
  	if (ret)
  		goto err_free_wq;
  
  	dc2c->result = (struct devcmd2_result *) dc2c->results_ring.descs;
  	dc2c->cmd_ring = (struct vnic_devcmd2 *) dc2c->wq.ring.descs;
  	dc2c->wq_ctrl = dc2c->wq.ctrl;
  	vdev->args[0] = (u64) dc2c->results_ring.base_addr | VNIC_PADDR_TARGET;
  	vdev->args[1] = DEVCMD2_RING_SIZE;
  
  	ret = _svnic_dev_cmd2(vdev, CMD_INITIALIZE_DEVCMD2, VNIC_DVCMD_TMO);
  	if (ret < 0)
  		goto err_free_desc_ring;
  
  	vdev->devcmd_rtn = &_svnic_dev_cmd2;
  	pr_info("DEVCMD2 Initialized.
  ");
  
  	return ret;
  
  err_free_desc_ring:
  	svnic_dev_free_desc_ring(vdev, &dc2c->results_ring);
  
  err_free_wq:
  	svnic_wq_disable(&dc2c->wq);
  	svnic_wq_free(&dc2c->wq);
  
  err_free_devcmd2:
  	kfree(dc2c);
  	vdev->devcmd2 = NULL;
  
  	return ret;
  } /* end of svnic_dev_init_devcmd2 */
  
  static void vnic_dev_deinit_devcmd2(struct vnic_dev *vdev)
  {
  	struct devcmd2_controller *dc2c = vdev->devcmd2;
  
  	vdev->devcmd2 = NULL;
  	vdev->devcmd_rtn = NULL;
  
  	svnic_dev_free_desc_ring(vdev, &dc2c->results_ring);
  	svnic_wq_disable(&dc2c->wq);
  	svnic_wq_free(&dc2c->wq);
  	kfree(dc2c);
  }
  
  int svnic_dev_cmd(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
  	u64 *a0, u64 *a1, int wait)
  {
  	int err;
  
  	memset(vdev->args, 0, sizeof(vdev->args));
  	vdev->args[0] = *a0;
  	vdev->args[1] = *a1;
  
  	err = (*vdev->devcmd_rtn)(vdev, cmd, wait);
  
  	*a0 = vdev->args[0];
  	*a1 = vdev->args[1];
  
  	return  err;
  }
  
  int svnic_dev_fw_info(struct vnic_dev *vdev,
  	struct vnic_devcmd_fw_info **fw_info)
  {
  	u64 a0, a1 = 0;
  	int wait = VNIC_DVCMD_TMO;
  	int err = 0;
  
  	if (!vdev->fw_info) {
  		vdev->fw_info = pci_alloc_consistent(vdev->pdev,
  			sizeof(struct vnic_devcmd_fw_info),
  			&vdev->fw_info_pa);
  		if (!vdev->fw_info)
  			return -ENOMEM;
  
  		a0 = vdev->fw_info_pa;
  
  		/* only get fw_info once and cache it */
  		err = svnic_dev_cmd(vdev, CMD_MCPU_FW_INFO, &a0, &a1, wait);
  	}
  
  	*fw_info = vdev->fw_info;
  
  	return err;
  }
  
  int svnic_dev_spec(struct vnic_dev *vdev, unsigned int offset,
  	unsigned int size, void *value)
  {
  	u64 a0, a1;
  	int wait = VNIC_DVCMD_TMO;
  	int err;
  
  	a0 = offset;
  	a1 = size;
  
  	err = svnic_dev_cmd(vdev, CMD_DEV_SPEC, &a0, &a1, wait);
  
  	switch (size) {
  	case 1:
  		*(u8 *)value = (u8)a0;
  		break;
  	case 2:
  		*(u16 *)value = (u16)a0;
  		break;
  	case 4:
  		*(u32 *)value = (u32)a0;
  		break;
  	case 8:
  		*(u64 *)value = a0;
  		break;
  	default:
  		BUG();
  		break;
  	}
  
  	return err;
  }
  
  int svnic_dev_stats_clear(struct vnic_dev *vdev)
  {
  	u64 a0 = 0, a1 = 0;
  	int wait = VNIC_DVCMD_TMO;
  
  	return svnic_dev_cmd(vdev, CMD_STATS_CLEAR, &a0, &a1, wait);
  }
  
  int svnic_dev_stats_dump(struct vnic_dev *vdev, struct vnic_stats **stats)
  {
  	u64 a0, a1;
  	int wait = VNIC_DVCMD_TMO;
  
  	if (!vdev->stats) {
  		vdev->stats = pci_alloc_consistent(vdev->pdev,
  			sizeof(struct vnic_stats), &vdev->stats_pa);
  		if (!vdev->stats)
  			return -ENOMEM;
  	}
  
  	*stats = vdev->stats;
  	a0 = vdev->stats_pa;
  	a1 = sizeof(struct vnic_stats);
  
  	return svnic_dev_cmd(vdev, CMD_STATS_DUMP, &a0, &a1, wait);
  }
  
  int svnic_dev_close(struct vnic_dev *vdev)
  {
  	u64 a0 = 0, a1 = 0;
  	int wait = VNIC_DVCMD_TMO;
  
  	return svnic_dev_cmd(vdev, CMD_CLOSE, &a0, &a1, wait);
  }
  
  int svnic_dev_enable_wait(struct vnic_dev *vdev)
  {
  	u64 a0 = 0, a1 = 0;
  	int wait = VNIC_DVCMD_TMO;
  	int err = 0;
  
  	err = svnic_dev_cmd(vdev, CMD_ENABLE_WAIT, &a0, &a1, wait);
  	if (err == ERR_ECMDUNKNOWN)
  		return svnic_dev_cmd(vdev, CMD_ENABLE, &a0, &a1, wait);
  
  	return err;
  }
  
  int svnic_dev_disable(struct vnic_dev *vdev)
  {
  	u64 a0 = 0, a1 = 0;
  	int wait = VNIC_DVCMD_TMO;
  
  	return svnic_dev_cmd(vdev, CMD_DISABLE, &a0, &a1, wait);
  }
  
  int svnic_dev_open(struct vnic_dev *vdev, int arg)
  {
  	u64 a0 = (u32)arg, a1 = 0;
  	int wait = VNIC_DVCMD_TMO;
  
  	return svnic_dev_cmd(vdev, CMD_OPEN, &a0, &a1, wait);
  }
  
  int svnic_dev_open_done(struct vnic_dev *vdev, int *done)
  {
  	u64 a0 = 0, a1 = 0;
  	int wait = VNIC_DVCMD_TMO;
  	int err;
  
  	*done = 0;
  
  	err = svnic_dev_cmd(vdev, CMD_OPEN_STATUS, &a0, &a1, wait);
  	if (err)
  		return err;
  
  	*done = (a0 == 0);
  
  	return 0;
  }
  
  int svnic_dev_notify_set(struct vnic_dev *vdev, u16 intr)
  {
  	u64 a0, a1;
  	int wait = VNIC_DVCMD_TMO;
  
  	if (!vdev->notify) {
  		vdev->notify = pci_alloc_consistent(vdev->pdev,
  			sizeof(struct vnic_devcmd_notify),
  			&vdev->notify_pa);
  		if (!vdev->notify)
  			return -ENOMEM;
  	}
  
  	a0 = vdev->notify_pa;
  	a1 = ((u64)intr << 32) & VNIC_NOTIFY_INTR_MASK;
  	a1 += sizeof(struct vnic_devcmd_notify);
  
  	return svnic_dev_cmd(vdev, CMD_NOTIFY, &a0, &a1, wait);
  }
  
  void svnic_dev_notify_unset(struct vnic_dev *vdev)
  {
  	u64 a0, a1;
  	int wait = VNIC_DVCMD_TMO;
  
  	a0 = 0;  /* paddr = 0 to unset notify buffer */
  	a1 = VNIC_NOTIFY_INTR_MASK; /* intr num = -1 to unreg for intr */
  	a1 += sizeof(struct vnic_devcmd_notify);
  
  	svnic_dev_cmd(vdev, CMD_NOTIFY, &a0, &a1, wait);
  }
  
  static int vnic_dev_notify_ready(struct vnic_dev *vdev)
  {
  	u32 *words;
  	unsigned int nwords = sizeof(struct vnic_devcmd_notify) / 4;
  	unsigned int i;
  	u32 csum;
  
  	if (!vdev->notify)
  		return 0;
  
  	do {
  		csum = 0;
  		memcpy(&vdev->notify_copy, vdev->notify,
  			sizeof(struct vnic_devcmd_notify));
  		words = (u32 *)&vdev->notify_copy;
  		for (i = 1; i < nwords; i++)
  			csum += words[i];
  	} while (csum != words[0]);
  
  	return 1;
  }
  
  int svnic_dev_init(struct vnic_dev *vdev, int arg)
  {
  	u64 a0 = (u32)arg, a1 = 0;
  	int wait = VNIC_DVCMD_TMO;
  
  	return svnic_dev_cmd(vdev, CMD_INIT, &a0, &a1, wait);
  }
  
  int svnic_dev_link_status(struct vnic_dev *vdev)
  {
  	if (vdev->linkstatus)
  		return *vdev->linkstatus;
  
  	if (!vnic_dev_notify_ready(vdev))
  		return 0;
  
  	return vdev->notify_copy.link_state;
  }
  
  u32 svnic_dev_link_down_cnt(struct vnic_dev *vdev)
  {
  	if (!vnic_dev_notify_ready(vdev))
  		return 0;
  
  	return vdev->notify_copy.link_down_cnt;
  }
  
  void svnic_dev_set_intr_mode(struct vnic_dev *vdev,
  	enum vnic_dev_intr_mode intr_mode)
  {
  	vdev->intr_mode = intr_mode;
  }
  
  enum vnic_dev_intr_mode svnic_dev_get_intr_mode(struct vnic_dev *vdev)
  {
  	return vdev->intr_mode;
  }
  
  void svnic_dev_unregister(struct vnic_dev *vdev)
  {
  	if (vdev) {
  		if (vdev->notify)
  			pci_free_consistent(vdev->pdev,
  				sizeof(struct vnic_devcmd_notify),
  				vdev->notify,
  				vdev->notify_pa);
  		if (vdev->linkstatus)
  			pci_free_consistent(vdev->pdev,
  				sizeof(u32),
  				vdev->linkstatus,
  				vdev->linkstatus_pa);
  		if (vdev->stats)
  			pci_free_consistent(vdev->pdev,
  				sizeof(struct vnic_stats),
  				vdev->stats, vdev->stats_pa);
  		if (vdev->fw_info)
  			pci_free_consistent(vdev->pdev,
  				sizeof(struct vnic_devcmd_fw_info),
  				vdev->fw_info, vdev->fw_info_pa);
  		if (vdev->devcmd2)
  			vnic_dev_deinit_devcmd2(vdev);
  		kfree(vdev);
  	}
  }
  
  struct vnic_dev *svnic_dev_alloc_discover(struct vnic_dev *vdev,
  					  void *priv,
  					  struct pci_dev *pdev,
  					  struct vnic_dev_bar *bar,
  					  unsigned int num_bars)
  {
  	if (!vdev) {
  		vdev = kzalloc(sizeof(struct vnic_dev), GFP_ATOMIC);
  		if (!vdev)
  			return NULL;
  	}
  
  	vdev->priv = priv;
  	vdev->pdev = pdev;
  
  	if (vnic_dev_discover_res(vdev, bar, num_bars))
  		goto err_out;
  
  	return vdev;
  
  err_out:
  	svnic_dev_unregister(vdev);
  
  	return NULL;
  } /* end of svnic_dev_alloc_discover */
  
  /*
   * fallback option is left to keep the interface common for other vnics.
   */
  int svnic_dev_cmd_init(struct vnic_dev *vdev, int fallback)
  {
  	int err = -ENODEV;
  	void __iomem *p;
  
  	p = svnic_dev_get_res(vdev, RES_TYPE_DEVCMD2, 0);
  	if (p)
  		err = svnic_dev_init_devcmd2(vdev);
  	else
  		pr_err("DEVCMD2 resource not found.
  ");
  
  	return err;
  } /* end of svnic_dev_cmd_init */