diff mbox

[v6,1/9] snic: snic module infrastructure

Message ID 1432711182-17530-2-git-send-email-nmusini@cisco.com (mailing list archive)
State New, archived
Headers show

Commit Message

Narsimhulu Musini May 27, 2015, 7:19 a.m. UTC
snic_main.c contains module load and unload, global driver context,
PCI Registration, PCI probe and remove, SCSI ML registration functionality.

snic.h contains snic structure definition, snic global context, and
prototypes.

snic_attrs.c contains device attributes to list snic state, link state,
and driver version under /sys/class/scsi_host/host<id>/

Signed-off-by: Narsimhulu Musini <nmusini@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
---
* v4
- Replaced scratch pad usage with private data structure for internal use.
- Changed cmd_per_lun to default queue depth.
- Removed snic_os.h file and replaced the wrappers with direct linux API.

* v3
- Cleaned up unused functions, structure members, and redundant comments.
- Fixed a typo in time computation.

* v2
- Added Compile time macro for debugfs dependent functionality.

 drivers/scsi/snic/snic.h       |  415 ++++++++++++++++
 drivers/scsi/snic/snic_attrs.c |   79 +++
 drivers/scsi/snic/snic_main.c  | 1039 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1533 insertions(+)
 create mode 100644 drivers/scsi/snic/snic.h
 create mode 100644 drivers/scsi/snic/snic_attrs.c
 create mode 100644 drivers/scsi/snic/snic_main.c
diff mbox

Patch

diff --git a/drivers/scsi/snic/snic.h b/drivers/scsi/snic/snic.h
new file mode 100644
index 0000000..f0231fc
--- /dev/null
+++ b/drivers/scsi/snic/snic.h
@@ -0,0 +1,415 @@ 
+/*
+ * 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.
+ */
+
+#ifndef _SNIC_H_
+#define _SNIC_H_
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/workqueue.h>
+#include <linux/bitops.h>
+#include <linux/mempool.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+
+#include "snic_disc.h"
+#include "snic_io.h"
+#include "snic_res.h"
+#include "snic_trc.h"
+#include "snic_stats.h"
+#include "vnic_dev.h"
+#include "vnic_wq.h"
+#include "vnic_cq.h"
+#include "vnic_intr.h"
+#include "vnic_stats.h"
+#include "vnic_snic.h"
+
+#define SNIC_DRV_NAME		"snic"
+#define SNIC_DRV_DESCRIPTION	"Cisco SCSI NIC Driver"
+#define SNIC_DRV_VERSION	"0.0.1.18"
+#define PFX			SNIC_DRV_NAME ":"
+#define DFX			SNIC_DRV_NAME "%d: "
+
+#define DESC_CLEAN_LOW_WATERMARK	8
+#define SNIC_UCSM_DFLT_THROTTLE_CNT_BLD 16 /* UCSM default throttle count */
+#define SNIC_MAX_IO_REQ			50 /* scsi_cmnd tag map entries */
+#define SNIC_MIN_IO_REQ			8  /* Min IO throttle count */
+#define SNIC_IO_LOCKS			64 /* IO locks: power of 2 */
+#define SNIC_DFLT_QUEUE_DEPTH		32 /* Default Queue Depth */
+#define SNIC_MAX_QUEUE_DEPTH		64 /* Max Queue Depth */
+#define SNIC_DFLT_CMD_TIMEOUT		90 /* Extended tmo for FW */
+
+/*
+ * Tag bits used for special requests.
+ */
+#define SNIC_TAG_ABORT		BIT(30)		/* Tag indicating abort */
+#define SNIC_TAG_DEV_RST	BIT(29)		/* Tag for device reset */
+#define SNIC_TAG_IOCTL_DEV_RST	BIT(28)		/* Tag for User Device Reset */
+#define SNIC_TAG_MASK		(BIT(24) - 1)	/* Mask for lookup */
+#define SNIC_NO_TAG		-1
+
+/*
+ * Command flags to identify the type of command and for other future use
+ */
+#define SNIC_NO_FLAGS			0
+#define SNIC_IO_INITIALIZED		BIT(0)
+#define SNIC_IO_ISSUED			BIT(1)
+#define SNIC_IO_DONE			BIT(2)
+#define SNIC_IO_REQ_NULL		BIT(3)
+#define SNIC_IO_ABTS_PENDING		BIT(4)
+#define SNIC_IO_ABORTED			BIT(5)
+#define SNIC_IO_ABTS_ISSUED		BIT(6)
+#define SNIC_IO_TERM_ISSUED		BIT(7)
+#define SNIC_IO_ABTS_TIMEDOUT		BIT(8)
+#define SNIC_IO_ABTS_TERM_DONE		BIT(9)
+#define SNIC_IO_ABTS_TERM_REQ_NULL	BIT(10)
+#define SNIC_IO_ABTS_TERM_TIMEDOUT	BIT(11)
+#define SNIC_IO_INTERNAL_TERM_PENDING	BIT(12)
+#define SNIC_IO_INTERNAL_TERM_ISSUED	BIT(13)
+#define SNIC_DEVICE_RESET		BIT(14)
+#define SNIC_DEV_RST_ISSUED		BIT(15)
+#define SNIC_DEV_RST_TIMEDOUT		BIT(16)
+#define SNIC_DEV_RST_ABTS_ISSUED	BIT(17)
+#define SNIC_DEV_RST_TERM_ISSUED	BIT(18)
+#define SNIC_DEV_RST_DONE		BIT(19)
+#define SNIC_DEV_RST_REQ_NULL		BIT(20)
+#define SNIC_DEV_RST_ABTS_DONE		BIT(21)
+#define SNIC_DEV_RST_TERM_DONE		BIT(22)
+#define SNIC_DEV_RST_ABTS_PENDING	BIT(23)
+#define SNIC_DEV_RST_PENDING		BIT(24)
+#define SNIC_DEV_RST_NOTSUP		BIT(25)
+#define SNIC_SCSI_CLEANUP		BIT(26)
+#define SNIC_HOST_RESET_ISSUED		BIT(27)
+
+#define SNIC_ABTS_TIMEOUT		30000		/* msec */
+#define SNIC_LUN_RESET_TIMEOUT		30000		/* msec */
+#define SNIC_HOST_RESET_TIMEOUT		30000		/* msec */
+
+
+/*
+ * These are protected by the hashed req_lock.
+ */
+#define CMD_SP(Cmnd)		\
+	(((struct snic_internal_io_state *)scsi_cmd_priv(Cmnd))->rqi)
+#define CMD_STATE(Cmnd)		\
+	(((struct snic_internal_io_state *)scsi_cmd_priv(Cmnd))->state)
+#define CMD_ABTS_STATUS(Cmnd)	\
+	(((struct snic_internal_io_state *)scsi_cmd_priv(Cmnd))->abts_status)
+#define CMD_LR_STATUS(Cmnd)	\
+	(((struct snic_internal_io_state *)scsi_cmd_priv(Cmnd))->lr_status)
+#define CMD_FLAGS(Cmnd)	\
+	(((struct snic_internal_io_state *)scsi_cmd_priv(Cmnd))->flags)
+
+#define SNIC_INVALID_CODE 0x100	/* Hdr Status val unused by firmware */
+
+#define SNIC_MAX_TARGET			256
+#define SNIC_FLAGS_NONE			(0)
+
+/* snic module params */
+extern unsigned int snic_max_qdepth;
+
+/* snic debugging */
+extern unsigned int snic_log_level;
+
+#define SNIC_MAIN_LOGGING	0x1
+#define SNIC_SCSI_LOGGING	0x2
+#define SNIC_ISR_LOGGING	0x8
+#define SNIC_DESC_LOGGING	0x10
+
+#define SNIC_CHECK_LOGGING(LEVEL, CMD)		\
+do {						\
+	if (unlikely(snic_log_level & LEVEL))	\
+		do {				\
+			CMD;			\
+		} while (0);			\
+} while (0)
+
+#define SNIC_MAIN_DBG(host, fmt, args...)	\
+	SNIC_CHECK_LOGGING(SNIC_MAIN_LOGGING,		\
+		shost_printk(KERN_INFO, host, fmt, ## args);)
+
+#define SNIC_SCSI_DBG(host, fmt, args...)	\
+	SNIC_CHECK_LOGGING(SNIC_SCSI_LOGGING,		\
+		shost_printk(KERN_INFO, host, fmt, ##args);)
+
+#define SNIC_DISC_DBG(host, fmt, args...)	\
+	SNIC_CHECK_LOGGING(SNIC_SCSI_LOGGING,		\
+		shost_printk(KERN_INFO, host, fmt, ##args);)
+
+#define SNIC_ISR_DBG(host, fmt, args...)	\
+	SNIC_CHECK_LOGGING(SNIC_ISR_LOGGING,		\
+		shost_printk(KERN_INFO, host, fmt, ##args);)
+
+#define SNIC_HOST_ERR(host, fmt, args...)		\
+	shost_printk(KERN_ERR, host, fmt, ##args)
+
+#define SNIC_HOST_INFO(host, fmt, args...)		\
+	shost_printk(KERN_INFO, host, fmt, ##args)
+
+#define SNIC_INFO(fmt, args...)				\
+	pr_info(PFX fmt, ## args)
+
+#define SNIC_DBG(fmt, args...)				\
+	pr_info(PFX fmt, ## args)
+
+#define SNIC_ERR(fmt, args...)				\
+	pr_err(PFX fmt, ## args)
+
+#ifdef DEBUG
+#define SNIC_BUG_ON(EXPR) \
+	({ \
+		if (EXPR) { \
+			SNIC_ERR("SNIC BUG(%s)\n", #EXPR); \
+			BUG_ON(EXPR); \
+		} \
+	})
+#else
+#define SNIC_BUG_ON(EXPR) \
+	({ \
+		if (EXPR) { \
+			SNIC_ERR("SNIC BUG(%s) at %s : %d\n", \
+				 #EXPR, __func__, __LINE__); \
+			WARN_ON_ONCE(EXPR); \
+		} \
+	})
+#endif
+
+/* Soft assert */
+#define SNIC_ASSERT_NOT_IMPL(EXPR) \
+	({ \
+		if (EXPR) {\
+			SNIC_INFO("Functionality not impl'ed at %s:%d\n", \
+				  __func__, __LINE__); \
+			WARN_ON_ONCE(EXPR); \
+		} \
+	 })
+
+
+extern const char *snic_state_str[];
+
+enum snic_intx_intr_index {
+	SNIC_INTX_WQ_RQ_COPYWQ,
+	SNIC_INTX_ERR,
+	SNIC_INTX_NOTIFY,
+	SNIC_INTX_INTR_MAX,
+};
+
+enum snic_msix_intr_index {
+	SNIC_MSIX_WQ,
+	SNIC_MSIX_IO_CMPL,
+	SNIC_MSIX_ERR_NOTIFY,
+	SNIC_MSIX_INTR_MAX,
+};
+
+struct snic_msix_entry {
+	int requested;
+	char devname[IFNAMSIZ];
+	irqreturn_t (*isr)(int, void *);
+	void *devid;
+};
+
+enum snic_state {
+	SNIC_INIT = 0,
+	SNIC_ERROR,
+	SNIC_ONLINE,
+	SNIC_OFFLINE,
+	SNIC_FWRESET,
+};
+
+#define SNIC_WQ_MAX		1
+#define SNIC_CQ_IO_CMPL_MAX	1
+#define SNIC_CQ_MAX		(SNIC_WQ_MAX + SNIC_CQ_IO_CMPL_MAX)
+
+/* firmware version information */
+struct snic_fw_info {
+	u32	fw_ver;
+	u32	hid;			/* u16 hid | u16 vnic id */
+	u32	max_concur_ios;		/* max concurrent ios */
+	u32	max_sgs_per_cmd;	/* max sgls per IO */
+	u32	max_io_sz;		/* max io size supported */
+	u32	hba_cap;		/* hba capabilities */
+	u32	max_tgts;		/* max tgts supported */
+	u16	io_tmo;			/* FW Extended timeout */
+	struct completion *wait;	/* protected by snic lock*/
+};
+
+/*
+ * snic_work item : defined to process asynchronous events
+ */
+struct snic_work {
+	struct work_struct work;
+	u16	ev_id;
+	u64	*ev_data;
+};
+
+/*
+ * snic structure to represent SCSI vNIC
+ */
+struct snic {
+	/* snic specific members */
+	struct list_head list;
+	char name[IFNAMSIZ];
+	atomic_t state;
+	spinlock_t snic_lock;
+	struct completion *remove_wait;
+	bool in_remove;
+	bool stop_link_events;		/* stop processing link events */
+
+	/* discovery related */
+	struct snic_disc disc;
+
+	/* Scsi Host info */
+	struct Scsi_Host *shost;
+
+	/* vnic related structures */
+	struct vnic_dev_bar bar0;
+
+	struct vnic_stats *stats;
+	unsigned long stats_time;
+	unsigned long stats_reset_time;
+
+	struct vnic_dev *vdev;
+
+	/* hw resource info */
+	unsigned int wq_count;
+	unsigned int cq_count;
+	unsigned int intr_count;
+	unsigned int err_intr_offset;
+
+	int link_status; /* retrieved from svnic_dev_link_status() */
+	u32 link_down_cnt;
+
+	/* pci related */
+	struct pci_dev *pdev;
+	struct msix_entry msix_entry[SNIC_MSIX_INTR_MAX];
+	struct snic_msix_entry msix[SNIC_MSIX_INTR_MAX];
+
+	/* io related info */
+	mempool_t *req_pool[SNIC_REQ_MAX_CACHES]; /* (??) */
+	____cacheline_aligned spinlock_t io_req_lock[SNIC_IO_LOCKS];
+
+	/* Maintain snic specific commands, cmds with no tag in spl_cmd_list */
+	____cacheline_aligned spinlock_t spl_cmd_lock;
+	struct list_head spl_cmd_list;
+
+	unsigned int max_tag_id;
+	atomic_t ios_inflight;		/* io in flight counter */
+
+	struct vnic_snic_config config;
+
+	struct work_struct link_work;
+
+	/* firmware information */
+	struct snic_fw_info fwinfo;
+
+	/* Work for processing Target related work */
+	struct work_struct tgt_work;
+
+	/* Work for processing Discovery */
+	struct work_struct disc_work;
+
+	/* stats related */
+	unsigned int reset_stats;
+	atomic64_t io_cmpl_skip;
+	struct snic_stats s_stats;	/* Per SNIC driver stats */
+
+	/* platform specific */
+#ifdef SNIC_DEBUG_FS
+	struct dentry *stats_host;	/* Per snic debugfs root */
+	struct dentry *stats_file;	/* Per snic debugfs file */
+	struct dentry *reset_stats_file;/* Per snic reset stats file */
+#endif
+
+	/* completion queue cache line section */
+	____cacheline_aligned struct vnic_cq cq[SNIC_CQ_MAX];
+
+	/* work queue cache line section */
+	____cacheline_aligned struct vnic_wq wq[SNIC_WQ_MAX];
+	spinlock_t wq_lock[SNIC_WQ_MAX];
+
+	/* interrupt resource cache line section */
+	____cacheline_aligned struct vnic_intr intr[SNIC_MSIX_INTR_MAX];
+}; /* end of snic structure */
+
+/*
+ * SNIC Driver's Global Data
+ */
+struct snic_global {
+	struct list_head snic_list;
+	spinlock_t snic_list_lock;
+
+	struct kmem_cache *req_cache[SNIC_REQ_MAX_CACHES];
+
+	struct workqueue_struct *event_q;
+
+#ifdef SNIC_DEBUG_FS
+	/* debugfs related global data */
+	struct dentry *trc_root;
+	struct dentry *stats_root;
+
+	struct snic_trc trc ____cacheline_aligned;
+
+#endif
+};
+
+extern struct snic_global *snic_glob;
+
+int snic_glob_init(void);
+void snic_glob_cleanup(void);
+
+extern struct workqueue_struct *snic_event_queue;
+extern struct device_attribute *snic_attrs[];
+
+int snic_queuecommand(struct Scsi_Host *, struct scsi_cmnd *);
+int snic_abort_cmd(struct scsi_cmnd *);
+int snic_device_reset(struct scsi_cmnd *);
+int snic_host_reset(struct scsi_cmnd *);
+int snic_reset(struct Scsi_Host *, struct scsi_cmnd *);
+void snic_shutdown_scsi_cleanup(struct snic *);
+
+
+int snic_request_intr(struct snic *);
+void snic_free_intr(struct snic *);
+int snic_set_intr_mode(struct snic *);
+void snic_clear_intr_mode(struct snic *);
+
+int snic_fwcq_cmpl_handler(struct snic *, int);
+int snic_wq_cmpl_handler(struct snic *, int);
+void snic_free_wq_buf(struct vnic_wq *, struct vnic_wq_buf *);
+
+
+void snic_log_q_error(struct snic *);
+void snic_handle_link_event(struct snic *);
+void snic_handle_link(struct work_struct *);
+
+int snic_queue_exch_ver_req(struct snic *);
+int snic_io_exch_ver_cmpl_handler(struct snic *, struct snic_fw_req *);
+
+int snic_queue_wq_desc(struct snic *, void *os_buf, u16 len);
+
+void snic_handle_untagged_req(struct snic *, struct snic_req_info *);
+void snic_release_untagged_req(struct snic *, struct snic_req_info *);
+void snic_free_all_untagged_reqs(struct snic *);
+int snic_get_conf(struct snic *);
+void snic_set_state(struct snic *, enum snic_state);
+int snic_get_state(struct snic *);
+const char *snic_state_to_str(unsigned int);
+void snic_hex_dump(char *, char *, int);
+void snic_print_desc(const char *fn, char *os_buf, int len);
+const char *show_opcode_name(int val);
+#endif /* _SNIC_H */
diff --git a/drivers/scsi/snic/snic_attrs.c b/drivers/scsi/snic/snic_attrs.c
new file mode 100644
index 0000000..9485d88
--- /dev/null
+++ b/drivers/scsi/snic/snic_attrs.c
@@ -0,0 +1,79 @@ 
+/*
+ * 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.
+ * [Insert appropriate license here when releasing outside of Cisco]
+ *
+ */
+
+#include <linux/string.h>
+#include <linux/device.h>
+
+#include "snic.h"
+
+static ssize_t
+snic_show_sym_name(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct snic *snic = shost_priv(class_to_shost(dev));
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", snic->name);
+}
+
+static ssize_t
+snic_show_state(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct snic *snic = shost_priv(class_to_shost(dev));
+
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+			snic_state_str[snic_get_state(snic)]);
+}
+
+static ssize_t
+snic_show_drv_version(struct device *dev,
+		      struct device_attribute *attr,
+		      char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%s\n", SNIC_DRV_VERSION);
+}
+
+static ssize_t
+snic_show_link_state(struct device *dev,
+		     struct device_attribute *attr,
+		     char *buf)
+{
+	struct snic *snic = shost_priv(class_to_shost(dev));
+
+	if (snic->config.xpt_type == SNIC_DAS)
+		snic->link_status = svnic_dev_link_status(snic->vdev);
+
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+			(snic->link_status) ? "Link Up" : "Link Down");
+}
+
+static DEVICE_ATTR(snic_sym_name, S_IRUGO, snic_show_sym_name, NULL);
+static DEVICE_ATTR(snic_state, S_IRUGO, snic_show_state, NULL);
+static DEVICE_ATTR(drv_version, S_IRUGO, snic_show_drv_version, NULL);
+static DEVICE_ATTR(link_state, S_IRUGO, snic_show_link_state, NULL);
+
+struct device_attribute *snic_attrs[] = {
+	&dev_attr_snic_sym_name,
+	&dev_attr_snic_state,
+	&dev_attr_drv_version,
+	&dev_attr_link_state,
+	NULL,
+};
diff --git a/drivers/scsi/snic/snic_main.c b/drivers/scsi/snic/snic_main.c
new file mode 100644
index 0000000..4d6cfa7
--- /dev/null
+++ b/drivers/scsi/snic/snic_main.c
@@ -0,0 +1,1039 @@ 
+/*
+ * 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/module.h>
+#include <linux/mempool.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/skbuff.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_tcq.h>
+
+#include "snic.h"
+#include "snic_fwint.h"
+
+#define PCI_DEVICE_ID_CISCO_SNIC	0x0046
+
+/* Supported devices by snic module */
+static struct pci_device_id snic_id_table[] = {
+	{PCI_DEVICE(0x1137, PCI_DEVICE_ID_CISCO_SNIC) },
+	{ 0, }	/* end of table */
+};
+
+unsigned int snic_log_level = 0x0;
+module_param(snic_log_level, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(snic_log_level, "bitmask for snic logging levels");
+
+#ifdef SNIC_DEBUG_FS
+unsigned int snic_trace_max_pages = 16;
+module_param(snic_trace_max_pages, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(snic_trace_max_pages,
+		"Total allocated memory pages for snic trace buffer");
+
+#endif
+unsigned int snic_max_qdepth = SNIC_DFLT_QUEUE_DEPTH;
+module_param(snic_max_qdepth, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(snic_max_qdepth, "Queue depth to report for each LUN");
+
+/*
+ * snic_slave_alloc : callback function to SCSI Mid Layer, called on
+ * scsi device initialization.
+ */
+static int
+snic_slave_alloc(struct scsi_device *sdev)
+{
+	struct snic_tgt *tgt = starget_to_tgt(scsi_target(sdev));
+
+	if (!tgt || snic_tgt_chkready(tgt))
+		return -ENXIO;
+
+	return 0;
+}
+
+/*
+ * snic_slave_configure : callback function to SCSI Mid Layer, called on
+ * scsi device initialization.
+ */
+static int
+snic_slave_configure(struct scsi_device *sdev)
+{
+	struct snic *snic = shost_priv(sdev->host);
+	u32 qdepth = 0, max_ios = 0;
+	int tmo = SNIC_DFLT_CMD_TIMEOUT * HZ;
+
+	/* Set Queue Depth */
+	max_ios = snic_max_qdepth;
+	qdepth = min_t(u32, max_ios, SNIC_MAX_QUEUE_DEPTH);
+	scsi_change_queue_depth(sdev, qdepth);
+
+	if (snic->fwinfo.io_tmo > 1)
+		tmo = snic->fwinfo.io_tmo * HZ;
+
+	/* FW requires extended timeouts */
+	blk_queue_rq_timeout(sdev->request_queue, tmo);
+
+	return 0;
+}
+
+static int
+snic_change_queue_depth(struct scsi_device *sdev, int qdepth)
+{
+	int qsz = 0;
+
+	qsz = min_t(u32, qdepth, SNIC_MAX_QUEUE_DEPTH);
+	scsi_change_queue_depth(sdev, qsz);
+	SNIC_INFO("QDepth Changed to %d\n", sdev->queue_depth);
+
+	return sdev->queue_depth;
+}
+
+static struct scsi_host_template snic_host_template = {
+	.module = THIS_MODULE,
+	.name = SNIC_DRV_NAME,
+	.queuecommand = snic_queuecommand,
+	.eh_abort_handler = snic_abort_cmd,
+	.eh_device_reset_handler = snic_device_reset,
+	.eh_host_reset_handler = snic_host_reset,
+	.slave_alloc = snic_slave_alloc,
+	.slave_configure = snic_slave_configure,
+	.change_queue_depth = snic_change_queue_depth,
+	.this_id = -1,
+	.cmd_per_lun = SNIC_DFLT_QUEUE_DEPTH,
+	.can_queue = SNIC_MAX_IO_REQ,
+	.use_clustering = ENABLE_CLUSTERING,
+	.sg_tablesize = SNIC_MAX_SG_DESC_CNT,
+	.max_sectors = 0x800,
+	.shost_attrs = snic_attrs,
+	.use_blk_tags = 1,
+	.track_queue_depth = 1,
+	.cmd_size = sizeof(struct snic_internal_io_state),
+	.proc_name = "snic_scsi",
+};
+
+/*
+ * snic_handle_link_event : Handles link events such as link up/down/error
+ */
+void
+snic_handle_link_event(struct snic *snic)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&snic->snic_lock, flags);
+	if (snic->stop_link_events) {
+		spin_unlock_irqrestore(&snic->snic_lock, flags);
+
+		return;
+	}
+	spin_unlock_irqrestore(&snic->snic_lock, flags);
+
+	queue_work(snic_glob->event_q, &snic->link_work);
+} /* end of snic_handle_link_event */
+
+/*
+ * snic_notify_set : sets notification area
+ * This notification area is to receive events from fw
+ * Note: snic supports only MSIX interrupts, in which we can just call
+ *  svnic_dev_notify_set directly
+ */
+static int
+snic_notify_set(struct snic *snic)
+{
+	int ret = 0;
+	enum vnic_dev_intr_mode intr_mode;
+
+	intr_mode = svnic_dev_get_intr_mode(snic->vdev);
+
+	if (intr_mode == VNIC_DEV_INTR_MODE_MSIX) {
+		ret = svnic_dev_notify_set(snic->vdev, SNIC_MSIX_ERR_NOTIFY);
+	} else {
+		SNIC_HOST_ERR(snic->shost,
+			      "Interrupt mode should be setup before devcmd notify set %d\n",
+			      intr_mode);
+		ret = -1;
+	}
+
+	return ret;
+} /* end of snic_notify_set */
+
+/*
+ * snic_dev_wait : polls vnic open status.
+ */
+static int
+snic_dev_wait(struct vnic_dev *vdev,
+		int (*start)(struct vnic_dev *, int),
+		int (*finished)(struct vnic_dev *, int *),
+		int arg)
+{
+	unsigned long time;
+	int ret, done;
+	int retry_cnt = 0;
+
+	ret = start(vdev, arg);
+	if (ret)
+		return ret;
+
+	/*
+	 * Wait for func to complete...2 seconds max.
+	 *
+	 * Sometimes schedule_timeout_uninterruptible take long	time
+	 * to wakeup, which results skipping retry. The retry counter
+	 * ensures to retry at least two times.
+	 */
+	time = jiffies + (HZ * 2);
+	do {
+		ret = finished(vdev, &done);
+		if (ret)
+			return ret;
+
+		if (done)
+			return 0;
+		schedule_timeout_uninterruptible(HZ/10);
+		++retry_cnt;
+	} while (time_after(time, jiffies) || (retry_cnt < 3));
+
+	return -ETIMEDOUT;
+} /* end of snic_dev_wait */
+
+/*
+ * snic_cleanup: called by snic_remove
+ * Stops the snic device, masks all interrupts, Completed CQ entries are
+ * drained. Posted WQ/RQ/Copy-WQ entries are cleanup
+ */
+static int
+snic_cleanup(struct snic *snic)
+{
+	unsigned int i;
+	int ret;
+
+	svnic_dev_disable(snic->vdev);
+	for (i = 0; i < snic->intr_count; i++)
+		svnic_intr_mask(&snic->intr[i]);
+
+	for (i = 0; i < snic->wq_count; i++) {
+		ret = svnic_wq_disable(&snic->wq[i]);
+		if (ret)
+			return ret;
+	}
+
+	/* Clean up completed IOs */
+	snic_fwcq_cmpl_handler(snic, -1);
+
+	snic_wq_cmpl_handler(snic, -1);
+
+	/* Clean up the IOs that have not completed */
+	for (i = 0; i < snic->wq_count; i++)
+		svnic_wq_clean(&snic->wq[i], snic_free_wq_buf);
+
+	for (i = 0; i < snic->cq_count; i++)
+		svnic_cq_clean(&snic->cq[i]);
+
+	for (i = 0; i < snic->intr_count; i++)
+		svnic_intr_clean(&snic->intr[i]);
+
+	/* Cleanup snic specific requests */
+	snic_free_all_untagged_reqs(snic);
+
+	/* Cleanup Pending SCSI commands */
+	snic_shutdown_scsi_cleanup(snic);
+
+	for (i = 0; i < SNIC_REQ_MAX_CACHES; i++)
+		mempool_destroy(snic->req_pool[i]);
+
+	return 0;
+} /* end of snic_cleanup */
+
+
+static void
+snic_iounmap(struct snic *snic)
+{
+	if (snic->bar0.vaddr)
+		iounmap(snic->bar0.vaddr);
+}
+
+/*
+ * snic_vdev_open_done : polls for svnic_dev_open cmd completion.
+ */
+static int
+snic_vdev_open_done(struct vnic_dev *vdev, int *done)
+{
+	struct snic *snic = svnic_dev_priv(vdev);
+	int ret;
+	int nretries = 5;
+
+	do {
+		ret = svnic_dev_open_done(vdev, done);
+		if (ret == 0)
+			break;
+
+		SNIC_HOST_INFO(snic->shost, "VNIC_DEV_OPEN Timedout.\n");
+	} while (nretries--);
+
+	return ret;
+} /* end of snic_vdev_open_done */
+
+/*
+ * snic_add_host : registers scsi host with ML
+ */
+static int
+snic_add_host(struct Scsi_Host *shost, struct pci_dev *pdev)
+{
+	int ret = 0;
+
+	ret = scsi_add_host(shost, &pdev->dev);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "snic: scsi_add_host failed. %d\n",
+			      ret);
+
+		return ret;
+	}
+
+	SNIC_BUG_ON(shost->work_q != NULL);
+	snprintf(shost->work_q_name, sizeof(shost->work_q_name), "scsi_wq_%d",
+		 shost->host_no);
+	shost->work_q = create_singlethread_workqueue(shost->work_q_name);
+	if (!shost->work_q) {
+		SNIC_HOST_ERR(shost, "Failed to Create ScsiHost wq.\n");
+
+		ret = -ENOMEM;
+	}
+
+	return ret;
+} /* end of snic_add_host */
+
+static void
+snic_del_host(struct Scsi_Host *shost)
+{
+	if (!shost->work_q)
+		return;
+
+	destroy_workqueue(shost->work_q);
+	shost->work_q = NULL;
+	scsi_remove_host(shost);
+}
+
+int
+snic_get_state(struct snic *snic)
+{
+	return atomic_read(&snic->state);
+}
+
+void
+snic_set_state(struct snic *snic, enum snic_state state)
+{
+	SNIC_HOST_INFO(snic->shost, "snic state change from %s to %s\n",
+		       snic_state_to_str(snic_get_state(snic)),
+		       snic_state_to_str(state));
+
+	atomic_set(&snic->state, state);
+}
+
+/*
+ * snic_probe : Initialize the snic interface.
+ */
+static int
+snic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	struct Scsi_Host *shost;
+	struct snic *snic;
+	mempool_t *pool;
+	unsigned long flags;
+	u32 max_ios = 0;
+	int ret, i;
+
+	/* Device Information */
+	SNIC_INFO("snic device %4x:%4x:%4x:%4x: ",
+		  pdev->vendor, pdev->device, pdev->subsystem_vendor,
+		  pdev->subsystem_device);
+
+	SNIC_INFO("snic device bus %x: slot %x: fn %x\n",
+		  pdev->bus->number, PCI_SLOT(pdev->devfn),
+		  PCI_FUNC(pdev->devfn));
+
+	/*
+	 * Allocate SCSI Host and setup association between host, and snic
+	 */
+	shost = scsi_host_alloc(&snic_host_template, sizeof(struct snic));
+	if (!shost) {
+		SNIC_ERR("Unable to alloc scsi_host\n");
+		ret = -ENOMEM;
+
+		goto prob_end;
+	}
+	snic = shost_priv(shost);
+	snic->shost = shost;
+
+	snprintf(snic->name, sizeof(snic->name) - 1, "%s%d", SNIC_DRV_NAME,
+		 shost->host_no);
+
+	SNIC_HOST_INFO(shost,
+		       "snic%d = %p shost = %p device bus %x: slot %x: fn %x\n",
+		       shost->host_no, snic, shost, pdev->bus->number,
+		       PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
+#ifdef SNIC_DEBUG_FS
+	/* Per snic debugfs init */
+	ret = snic_stats_debugfs_init(snic);
+	if (ret) {
+		SNIC_HOST_ERR(snic->shost,
+			      "Failed to initialize debugfs stats\n");
+		snic_stats_debugfs_remove(snic);
+	}
+#endif
+
+	/* Setup PCI Resources */
+	pci_set_drvdata(pdev, snic);
+	snic->pdev = pdev;
+
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Cannot enable PCI Resources, aborting : %d\n",
+			      ret);
+
+		goto err_free_snic;
+	}
+
+	ret = pci_request_regions(pdev, SNIC_DRV_NAME);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Cannot obtain PCI Resources, aborting : %d\n",
+			      ret);
+
+		goto err_pci_disable;
+	}
+
+	pci_set_master(pdev);
+
+	/*
+	 * Query PCI Controller on system for DMA addressing
+	 * limitation for the device. Try 43-bit first, and
+	 * fail to 32-bit.
+	 */
+	ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(43));
+	if (ret) {
+		ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+		if (ret) {
+			SNIC_HOST_ERR(shost,
+				      "No Usable DMA Configuration, aborting %d\n",
+				      ret);
+
+			goto err_rel_regions;
+		}
+
+		ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
+		if (ret) {
+			SNIC_HOST_ERR(shost,
+				      "Unable to obtain 32-bit DMA for consistent allocations, aborting: %d\n",
+				      ret);
+
+			goto err_rel_regions;
+		}
+	} else {
+		ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(43));
+		if (ret) {
+			SNIC_HOST_ERR(shost,
+				      "Unable to obtain 43-bit DMA for consistent allocations. aborting: %d\n",
+				      ret);
+
+			goto err_rel_regions;
+		}
+	}
+
+
+	/* Map vNIC resources from BAR0 */
+	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
+		SNIC_HOST_ERR(shost, "BAR0 not memory mappable aborting.\n");
+
+		ret = -ENODEV;
+		goto err_rel_regions;
+	}
+
+	snic->bar0.vaddr = pci_iomap(pdev, 0, 0);
+	if (!snic->bar0.vaddr) {
+		SNIC_HOST_ERR(shost,
+			      "Cannot memory map BAR0 res hdr aborting.\n");
+
+		ret = -ENODEV;
+		goto err_rel_regions;
+	}
+
+	snic->bar0.bus_addr = pci_resource_start(pdev, 0);
+	snic->bar0.len = pci_resource_len(pdev, 0);
+	SNIC_BUG_ON(snic->bar0.bus_addr == 0);
+
+	/* Devcmd2 Resource Allocation and Initialization */
+	snic->vdev = svnic_dev_alloc_discover(NULL, snic, pdev, &snic->bar0, 1);
+	if (!snic->vdev) {
+		SNIC_HOST_ERR(shost, "vNIC Resource Discovery Failed.\n");
+
+		ret = -ENODEV;
+		goto err_iounmap;
+	}
+
+	ret = svnic_dev_cmd_init(snic->vdev, 0);
+	if (ret) {
+		SNIC_HOST_INFO(shost, "Devcmd2 Init Failed. err = %d\n", ret);
+
+		goto err_vnic_unreg;
+	}
+
+	ret = snic_dev_wait(snic->vdev, svnic_dev_open, snic_vdev_open_done, 0);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "vNIC dev open failed, aborting. %d\n",
+			      ret);
+
+		goto err_vnic_unreg;
+	}
+
+	ret = svnic_dev_init(snic->vdev, 0);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "vNIC dev init failed. aborting. %d\n",
+			      ret);
+
+		goto err_dev_close;
+	}
+
+	/* Get vNIC information */
+	ret = snic_get_vnic_config(snic);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Get vNIC configuration failed, aborting. %d\n",
+			      ret);
+
+		goto err_dev_close;
+	}
+
+	/* Configure Maximum Outstanding IO reqs */
+	max_ios = snic->config.io_throttle_count;
+	if (max_ios != SNIC_UCSM_DFLT_THROTTLE_CNT_BLD)
+		shost->can_queue = min_t(u32, SNIC_MAX_IO_REQ,
+					 max_t(u32, SNIC_MIN_IO_REQ, max_ios));
+
+	snic->max_tag_id = shost->can_queue;
+
+	ret = scsi_init_shared_tag_map(shost, snic->max_tag_id);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Unable to alloc shared tag map. %d\n",
+			      ret);
+
+		goto err_dev_close;
+	}
+
+	shost->max_lun = snic->config.luns_per_tgt;
+	shost->max_id = SNIC_MAX_TARGET;
+
+	shost->max_cmd_len = MAX_COMMAND_SIZE; /*defined in scsi_cmnd.h*/
+
+	snic_get_res_counts(snic);
+
+	/*
+	 * Assumption: Only MSIx is supported
+	 */
+	ret = snic_set_intr_mode(snic);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Failed to set intr mode aborting. %d\n",
+			      ret);
+
+		goto err_dev_close;
+	}
+
+	ret = snic_alloc_vnic_res(snic);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Failed to alloc vNIC resources aborting. %d\n",
+			      ret);
+
+		goto err_clear_intr;
+	}
+
+	/* Initialize specific lists */
+	INIT_LIST_HEAD(&snic->list);
+
+	/*
+	 * spl_cmd_list for maintaining snic specific cmds
+	 * such as EXCH_VER_REQ, REPORT_TARGETS etc
+	 */
+	INIT_LIST_HEAD(&snic->spl_cmd_list);
+	spin_lock_init(&snic->spl_cmd_lock);
+
+	/* initialize all snic locks */
+	spin_lock_init(&snic->snic_lock);
+
+	for (i = 0; i < SNIC_WQ_MAX; i++)
+		spin_lock_init(&snic->wq_lock[i]);
+
+	for (i = 0; i < SNIC_IO_LOCKS; i++)
+		spin_lock_init(&snic->io_req_lock[i]);
+
+	pool = mempool_create_slab_pool(2,
+				snic_glob->req_cache[SNIC_REQ_CACHE_DFLT_SGL]);
+	if (!pool) {
+		SNIC_HOST_ERR(shost, "dflt sgl pool creation failed\n");
+
+		goto err_free_res;
+	}
+
+	snic->req_pool[SNIC_REQ_CACHE_DFLT_SGL] = pool;
+
+	pool = mempool_create_slab_pool(2,
+				snic_glob->req_cache[SNIC_REQ_CACHE_MAX_SGL]);
+	if (!pool) {
+		SNIC_HOST_ERR(shost, "max sgl pool creation failed\n");
+
+		goto err_free_dflt_sgl_pool;
+	}
+
+	snic->req_pool[SNIC_REQ_CACHE_MAX_SGL] = pool;
+
+	pool = mempool_create_slab_pool(2,
+				snic_glob->req_cache[SNIC_REQ_TM_CACHE]);
+	if (!pool) {
+		SNIC_HOST_ERR(shost, "snic tmreq info pool creation failed.\n");
+
+		goto err_free_max_sgl_pool;
+	}
+
+	snic->req_pool[SNIC_REQ_TM_CACHE] = pool;
+
+	/* Initialize snic state */
+	atomic_set(&snic->state, SNIC_INIT);
+
+	atomic_set(&snic->ios_inflight, 0);
+
+	/* Setup notification buffer area */
+	ret = snic_notify_set(snic);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Failed to alloc notify buffer aborting. %d\n",
+			      ret);
+
+		goto err_free_tmreq_pool;
+	}
+
+	/*
+	 * Initialization done with PCI system, hardware, firmware.
+	 * Add shost to SCSI
+	 */
+	ret = snic_add_host(shost, pdev);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Adding scsi host Failed ... exiting. %d\n",
+			      ret);
+
+		goto err_notify_unset;
+	}
+
+	spin_lock_irqsave(&snic_glob->snic_list_lock, flags);
+	list_add_tail(&snic->list, &snic_glob->snic_list);
+	spin_unlock_irqrestore(&snic_glob->snic_list_lock, flags);
+
+	snic_disc_init(&snic->disc);
+	INIT_WORK(&snic->tgt_work, snic_handle_tgt_disc);
+	INIT_WORK(&snic->disc_work, snic_handle_disc);
+	INIT_WORK(&snic->link_work, snic_handle_link);
+
+	/* Enable all queues */
+	for (i = 0; i < snic->wq_count; i++)
+		svnic_wq_enable(&snic->wq[i]);
+
+	ret = svnic_dev_enable_wait(snic->vdev);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "vNIC dev enable failed w/ error %d\n",
+			      ret);
+
+		goto err_vdev_enable;
+	}
+
+	ret = snic_request_intr(snic);
+	if (ret) {
+		SNIC_HOST_ERR(shost, "Unable to request irq. %d\n", ret);
+
+		goto err_req_intr;
+	}
+
+	for (i = 0; i < snic->intr_count; i++)
+		svnic_intr_unmask(&snic->intr[i]);
+
+	snic_set_state(snic, SNIC_ONLINE);
+
+	/* Get snic params */
+	ret = snic_get_conf(snic);
+	if (ret) {
+		SNIC_HOST_ERR(shost,
+			      "Failed to get snic io config from FW w err %d\n",
+			      ret);
+
+		goto err_get_conf;
+	}
+
+	ret = snic_disc_start(snic);
+	if (ret) {
+		SNIC_HOST_ERR(shost, "snic_probe:Discovery Failed w err = %d\n",
+			      ret);
+
+		goto err_get_conf;
+	}
+
+	SNIC_HOST_INFO(shost, "SNIC Device Probe Successful.\n");
+
+	return 0;
+
+err_get_conf:
+	snic_free_all_untagged_reqs(snic);
+
+	for (i = 0; i < snic->intr_count; i++)
+		svnic_intr_mask(&snic->intr[i]);
+
+	snic_free_intr(snic);
+
+err_req_intr:
+	svnic_dev_disable(snic->vdev);
+
+err_vdev_enable:
+	for (i = 0; i < snic->wq_count; i++) {
+		int rc = 0;
+
+		rc = svnic_wq_disable(&snic->wq[i]);
+		if (rc) {
+			SNIC_HOST_ERR(shost,
+				      "WQ Disable Failed w/ err = %d\n", rc);
+
+			 break;
+		}
+	}
+	snic_del_host(snic->shost);
+
+err_notify_unset:
+	svnic_dev_notify_unset(snic->vdev);
+
+err_free_tmreq_pool:
+	mempool_destroy(snic->req_pool[SNIC_REQ_TM_CACHE]);
+
+err_free_max_sgl_pool:
+	mempool_destroy(snic->req_pool[SNIC_REQ_CACHE_MAX_SGL]);
+
+err_free_dflt_sgl_pool:
+	mempool_destroy(snic->req_pool[SNIC_REQ_CACHE_DFLT_SGL]);
+
+err_free_res:
+	snic_free_vnic_res(snic);
+
+err_clear_intr:
+	snic_clear_intr_mode(snic);
+
+err_dev_close:
+	svnic_dev_close(snic->vdev);
+
+err_vnic_unreg:
+	svnic_dev_unregister(snic->vdev);
+
+err_iounmap:
+	snic_iounmap(snic);
+
+err_rel_regions:
+	pci_release_regions(pdev);
+
+err_pci_disable:
+	pci_disable_device(pdev);
+
+err_free_snic:
+#ifdef SNIC_DEBUG_FS
+	snic_stats_debugfs_remove(snic);
+#endif
+	scsi_host_put(shost);
+	pci_set_drvdata(pdev, NULL);
+
+prob_end:
+	SNIC_INFO("sNIC device : bus %d: slot %d: fn %d Registration Failed.\n",
+		  pdev->bus->number, PCI_SLOT(pdev->devfn),
+		  PCI_FUNC(pdev->devfn));
+
+	return ret;
+} /* end of snic_probe */
+
+
+/*
+ * snic_remove : invoked on unbinding the interface to cleanup the
+ * resources allocated in snic_probe on initialization.
+ */
+static void
+snic_remove(struct pci_dev *pdev)
+{
+	struct snic *snic = pci_get_drvdata(pdev);
+	unsigned long flags;
+
+	if (!snic) {
+		SNIC_INFO("sNIC dev: bus %d slot %d fn %d snic inst is null.\n",
+			  pdev->bus->number, PCI_SLOT(pdev->devfn),
+			  PCI_FUNC(pdev->devfn));
+
+		return;
+	}
+
+	/*
+	 * Mark state so that the workqueue thread stops forwarding
+	 * received frames and link events. ISR and other threads
+	 * that can queue work items will also stop creating work
+	 * items on the snic workqueue
+	 */
+	snic_set_state(snic, SNIC_OFFLINE);
+	spin_lock_irqsave(&snic->snic_lock, flags);
+	snic->stop_link_events = 1;
+	spin_unlock_irqrestore(&snic->snic_lock, flags);
+
+	flush_workqueue(snic_glob->event_q);
+	snic_disc_term(snic);
+
+	spin_lock_irqsave(&snic->snic_lock, flags);
+	snic->in_remove = 1;
+	spin_unlock_irqrestore(&snic->snic_lock, flags);
+
+	/*
+	 * This stops the snic device, masks all interrupts, Completed
+	 * CQ entries are drained. Posted WQ/RQ/Copy-WQ entries are
+	 * cleanup
+	 */
+	snic_cleanup(snic);
+
+	spin_lock_irqsave(&snic_glob->snic_list_lock, flags);
+	list_del(&snic->list);
+	spin_unlock_irqrestore(&snic_glob->snic_list_lock, flags);
+
+	snic_tgt_del_all(snic);
+#ifdef SNIC_DEBUG_FS
+	snic_stats_debugfs_remove(snic);
+#endif
+	snic_del_host(snic->shost);
+
+	svnic_dev_notify_unset(snic->vdev);
+	snic_free_intr(snic);
+	snic_free_vnic_res(snic);
+	snic_clear_intr_mode(snic);
+	svnic_dev_close(snic->vdev);
+	svnic_dev_unregister(snic->vdev);
+	snic_iounmap(snic);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	pci_set_drvdata(pdev, NULL);
+
+	/* this frees Scsi_Host and snic memory (continuous chunk) */
+	scsi_host_put(snic->shost);
+} /* end of snic_remove */
+
+
+struct snic_global *snic_glob;
+
+/*
+ * snic_global_data_init: Initialize SNIC Global Data
+ * Notes: All the global lists, variables should be part of global data
+ * this helps in debugging.
+ */
+static int
+snic_global_data_init(void)
+{
+	int ret = 0;
+	struct kmem_cache *cachep;
+	ssize_t len = 0;
+
+	snic_glob = kzalloc(sizeof(*snic_glob), GFP_KERNEL);
+
+	if (!snic_glob) {
+		SNIC_ERR("Failed to allocate Global Context.\n");
+
+		ret = -ENOMEM;
+		goto gdi_end;
+	}
+
+#ifdef SNIC_DEBUG_FS
+	/* Debugfs related Initialization */
+	/* Create debugfs entries for snic */
+	ret = snic_debugfs_init();
+	if (ret < 0) {
+		SNIC_ERR("Failed to create sysfs dir for tracing and stats.\n");
+		snic_debugfs_term();
+		/* continue even if it fails */
+	}
+
+	/* Trace related Initialization */
+	/* Allocate memory for trace buffer */
+	ret = snic_trc_init();
+	if (ret < 0) {
+		SNIC_ERR("Trace buffer init failed, SNIC tracing disabled\n");
+		snic_trc_free();
+		/* continue even if it fails */
+	}
+
+#endif
+	INIT_LIST_HEAD(&snic_glob->snic_list);
+	spin_lock_init(&snic_glob->snic_list_lock);
+
+	/* Create a cache for allocation of snic_host_req+default size ESGLs */
+	len = sizeof(struct snic_req_info);
+	len += sizeof(struct snic_host_req) + sizeof(struct snic_dflt_sgl);
+	cachep = kmem_cache_create("snic_req_dfltsgl", len, SNIC_SG_DESC_ALIGN,
+				   SLAB_HWCACHE_ALIGN, NULL);
+	if (!cachep) {
+		SNIC_ERR("Failed to create snic default sgl slab\n");
+		ret = -ENOMEM;
+
+		goto err_dflt_req_slab;
+	}
+	snic_glob->req_cache[SNIC_REQ_CACHE_DFLT_SGL] = cachep;
+
+	/* Create a cache for allocation of max size Extended SGLs */
+	len = sizeof(struct snic_req_info);
+	len += sizeof(struct snic_host_req) + sizeof(struct snic_max_sgl);
+	cachep = kmem_cache_create("snic_req_maxsgl", len, SNIC_SG_DESC_ALIGN,
+				   SLAB_HWCACHE_ALIGN, NULL);
+	if (!cachep) {
+		SNIC_ERR("Failed to create snic max sgl slab\n");
+		ret = -ENOMEM;
+
+		goto err_max_req_slab;
+	}
+	snic_glob->req_cache[SNIC_REQ_CACHE_MAX_SGL] = cachep;
+
+	len = sizeof(struct snic_host_req);
+	cachep = kmem_cache_create("snic_req_maxsgl", len, SNIC_SG_DESC_ALIGN,
+				   SLAB_HWCACHE_ALIGN, NULL);
+	if (!cachep) {
+		SNIC_ERR("Failed to create snic tm req slab\n");
+		ret = -ENOMEM;
+
+		goto err_tmreq_slab;
+	}
+	snic_glob->req_cache[SNIC_REQ_TM_CACHE] = cachep;
+
+	/* snic_event queue */
+	snic_glob->event_q = create_singlethread_workqueue("snic_event_wq");
+	if (!snic_glob->event_q) {
+		SNIC_ERR("snic event queue create failed\n");
+		ret = -ENOMEM;
+
+		goto err_eventq;
+	}
+
+	return ret;
+
+err_eventq:
+	kmem_cache_destroy(snic_glob->req_cache[SNIC_REQ_TM_CACHE]);
+
+err_tmreq_slab:
+	kmem_cache_destroy(snic_glob->req_cache[SNIC_REQ_CACHE_MAX_SGL]);
+
+err_max_req_slab:
+	kmem_cache_destroy(snic_glob->req_cache[SNIC_REQ_CACHE_DFLT_SGL]);
+
+err_dflt_req_slab:
+#ifdef SNIC_DEBUG_FS
+	snic_trc_free();
+	snic_debugfs_term();
+#endif
+	kfree(snic_glob);
+	snic_glob = NULL;
+
+gdi_end:
+	return ret;
+} /* end of snic_glob_init */
+
+/*
+ * snic_global_data_cleanup : Frees SNIC Global Data
+ */
+static void
+snic_global_data_cleanup(void)
+{
+	SNIC_BUG_ON(snic_glob == NULL);
+
+	destroy_workqueue(snic_glob->event_q);
+	kmem_cache_destroy(snic_glob->req_cache[SNIC_REQ_TM_CACHE]);
+	kmem_cache_destroy(snic_glob->req_cache[SNIC_REQ_CACHE_MAX_SGL]);
+	kmem_cache_destroy(snic_glob->req_cache[SNIC_REQ_CACHE_DFLT_SGL]);
+
+#ifdef SNIC_DEBUG_FS
+	/* Freeing Trace Resources */
+	snic_trc_free();
+
+	/* Freeing Debugfs Resources */
+	snic_debugfs_term();
+#endif
+	kfree(snic_glob);
+	snic_glob = NULL;
+} /* end of snic_glob_cleanup */
+
+static struct pci_driver snic_driver = {
+	.name = SNIC_DRV_NAME,
+	.id_table = snic_id_table,
+	.probe = snic_probe,
+	.remove = snic_remove,
+};
+
+static int __init
+snic_init_module(void)
+{
+	int ret = 0;
+
+	SNIC_INFO("%s, ver %s\n", SNIC_DRV_DESCRIPTION, SNIC_DRV_VERSION);
+
+	ret = snic_global_data_init();
+	if (ret) {
+		SNIC_ERR("Failed to Initialize Global Data.\n");
+
+		return ret;
+	}
+
+	ret = pci_register_driver(&snic_driver);
+	if (ret < 0) {
+		SNIC_ERR("PCI driver register error\n");
+
+		goto err_pci_reg;
+	}
+
+	return ret;
+
+err_pci_reg:
+	snic_global_data_cleanup();
+
+	return ret;
+}
+
+static void __exit
+snic_cleanup_module(void)
+{
+	pci_unregister_driver(&snic_driver);
+	snic_global_data_cleanup();
+}
+
+module_init(snic_init_module);
+module_exit(snic_cleanup_module);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION(SNIC_DRV_DESCRIPTION);
+MODULE_VERSION(SNIC_DRV_VERSION);
+MODULE_DEVICE_TABLE(pci, snic_id_table);
+MODULE_AUTHOR("Narsimhulu Musini <nmusini@cisco.com>, "
+	      "Sesidhar Baddela <sebaddel@cisco.com>");