Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4060 insertions, 0 deletions

diff --git a/drivers/scsi/megaraid/megaraid_mbox.c b/drivers/scsi/megaraid/megaraid_mbox.c
new file mode 100644
index 000000000..132de68c1
--- /dev/null
+++ b/drivers/scsi/megaraid/megaraid_mbox.c
@@ -0,0 +1,4060 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ *			Linux MegaRAID device driver
+ *
+ * Copyright (c) 2003-2004  LSI Logic Corporation.
+ *
+ * FILE		: megaraid_mbox.c
+ * Version	: v2.20.5.1 (Nov 16 2006)
+ *
+ * Authors:
+ * 	Atul Mukker		<Atul.Mukker@lsi.com>
+ * 	Sreenivas Bagalkote	<Sreenivas.Bagalkote@lsi.com>
+ * 	Manoj Jose		<Manoj.Jose@lsi.com>
+ * 	Seokmann Ju
+ *
+ * List of supported controllers
+ *
+ * OEM	Product Name			VID	DID	SSVID	SSID
+ * ---	------------			---	---	----	----
+ * Dell PERC3/QC			101E	1960	1028	0471
+ * Dell PERC3/DC			101E	1960	1028	0493
+ * Dell PERC3/SC			101E	1960	1028	0475
+ * Dell PERC3/Di			1028	1960	1028	0123
+ * Dell PERC4/SC			1000	1960	1028	0520
+ * Dell PERC4/DC			1000	1960	1028	0518
+ * Dell PERC4/QC			1000	0407	1028	0531
+ * Dell PERC4/Di			1028	000F	1028	014A
+ * Dell PERC 4e/Si			1028	0013	1028	016c
+ * Dell PERC 4e/Di			1028	0013	1028	016d
+ * Dell PERC 4e/Di			1028	0013	1028	016e
+ * Dell PERC 4e/Di			1028	0013	1028	016f
+ * Dell PERC 4e/Di			1028	0013	1028	0170
+ * Dell PERC 4e/DC			1000	0408	1028	0002
+ * Dell PERC 4e/SC			1000	0408	1028	0001
+ *
+ * LSI MegaRAID SCSI 320-0		1000	1960	1000	A520
+ * LSI MegaRAID SCSI 320-1		1000	1960	1000	0520
+ * LSI MegaRAID SCSI 320-2		1000	1960	1000	0518
+ * LSI MegaRAID SCSI 320-0X		1000	0407	1000	0530
+ * LSI MegaRAID SCSI 320-2X		1000	0407	1000	0532
+ * LSI MegaRAID SCSI 320-4X		1000	0407	1000	0531
+ * LSI MegaRAID SCSI 320-1E		1000	0408	1000	0001
+ * LSI MegaRAID SCSI 320-2E		1000	0408	1000	0002
+ * LSI MegaRAID SATA 150-4		1000	1960	1000	4523
+ * LSI MegaRAID SATA 150-6		1000	1960	1000	0523
+ * LSI MegaRAID SATA 300-4X		1000	0409	1000	3004
+ * LSI MegaRAID SATA 300-8X		1000	0409	1000	3008
+ *
+ * INTEL RAID Controller SRCU42X	1000	0407	8086	0532
+ * INTEL RAID Controller SRCS16		1000	1960	8086	0523
+ * INTEL RAID Controller SRCU42E	1000	0408	8086	0002
+ * INTEL RAID Controller SRCZCRX	1000	0407	8086	0530
+ * INTEL RAID Controller SRCS28X	1000	0409	8086	3008
+ * INTEL RAID Controller SROMBU42E	1000	0408	8086	3431
+ * INTEL RAID Controller SROMBU42E	1000	0408	8086	3499
+ * INTEL RAID Controller SRCU51L	1000	1960	8086	0520
+ *
+ * FSC	MegaRAID PCI Express ROMB	1000	0408	1734	1065
+ *
+ * ACER	MegaRAID ROMB-2E		1000	0408	1025	004D
+ *
+ * NEC	MegaRAID PCI Express ROMB	1000	0408	1033	8287
+ *
+ * For history of changes, see Documentation/scsi/ChangeLog.megaraid
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include "megaraid_mbox.h"
+
+static int megaraid_init(void);
+static void megaraid_exit(void);
+
+static int megaraid_probe_one(struct pci_dev*, const struct pci_device_id *);
+static void megaraid_detach_one(struct pci_dev *);
+static void megaraid_mbox_shutdown(struct pci_dev *);
+
+static int megaraid_io_attach(adapter_t *);
+static void megaraid_io_detach(adapter_t *);
+
+static int megaraid_init_mbox(adapter_t *);
+static void megaraid_fini_mbox(adapter_t *);
+
+static int megaraid_alloc_cmd_packets(adapter_t *);
+static void megaraid_free_cmd_packets(adapter_t *);
+
+static int megaraid_mbox_setup_dma_pools(adapter_t *);
+static void megaraid_mbox_teardown_dma_pools(adapter_t *);
+
+static int megaraid_sysfs_alloc_resources(adapter_t *);
+static void megaraid_sysfs_free_resources(adapter_t *);
+
+static int megaraid_abort_handler(struct scsi_cmnd *);
+static int megaraid_reset_handler(struct scsi_cmnd *);
+
+static int mbox_post_sync_cmd(adapter_t *, uint8_t []);
+static int mbox_post_sync_cmd_fast(adapter_t *, uint8_t []);
+static int megaraid_busywait_mbox(mraid_device_t *);
+static int megaraid_mbox_product_info(adapter_t *);
+static int megaraid_mbox_extended_cdb(adapter_t *);
+static int megaraid_mbox_support_ha(adapter_t *, uint16_t *);
+static int megaraid_mbox_support_random_del(adapter_t *);
+static int megaraid_mbox_get_max_sg(adapter_t *);
+static void megaraid_mbox_enum_raid_scsi(adapter_t *);
+static void megaraid_mbox_flush_cache(adapter_t *);
+static int megaraid_mbox_fire_sync_cmd(adapter_t *);
+
+static void megaraid_mbox_display_scb(adapter_t *, scb_t *);
+static void megaraid_mbox_setup_device_map(adapter_t *);
+
+static int megaraid_queue_command(struct Scsi_Host *, struct scsi_cmnd *);
+static scb_t *megaraid_mbox_build_cmd(adapter_t *, struct scsi_cmnd *, int *);
+static void megaraid_mbox_runpendq(adapter_t *, scb_t *);
+static void megaraid_mbox_prepare_pthru(adapter_t *, scb_t *,
+		struct scsi_cmnd *);
+static void megaraid_mbox_prepare_epthru(adapter_t *, scb_t *,
+		struct scsi_cmnd *);
+
+static irqreturn_t megaraid_isr(int, void *);
+
+static void megaraid_mbox_dpc(unsigned long);
+
+static ssize_t megaraid_mbox_app_hndl_show(struct device *, struct device_attribute *attr, char *);
+static ssize_t megaraid_mbox_ld_show(struct device *, struct device_attribute *attr, char *);
+
+static int megaraid_cmm_register(adapter_t *);
+static int megaraid_cmm_unregister(adapter_t *);
+static int megaraid_mbox_mm_handler(unsigned long, uioc_t *, uint32_t);
+static int megaraid_mbox_mm_command(adapter_t *, uioc_t *);
+static void megaraid_mbox_mm_done(adapter_t *, scb_t *);
+static int gather_hbainfo(adapter_t *, mraid_hba_info_t *);
+static int wait_till_fw_empty(adapter_t *);
+
+
+
+MODULE_AUTHOR("megaraidlinux@lsi.com");
+MODULE_DESCRIPTION("LSI Logic MegaRAID Mailbox Driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(MEGARAID_VERSION);
+
+/*
+ * ### modules parameters for driver ###
+ */
+
+/*
+ * Set to enable driver to expose unconfigured disk to kernel
+ */
+static int megaraid_expose_unconf_disks = 0;
+module_param_named(unconf_disks, megaraid_expose_unconf_disks, int, 0);
+MODULE_PARM_DESC(unconf_disks,
+	"Set to expose unconfigured disks to kernel (default=0)");
+
+/*
+ * driver wait time if the adapter's mailbox is busy
+ */
+static unsigned int max_mbox_busy_wait = MBOX_BUSY_WAIT;
+module_param_named(busy_wait, max_mbox_busy_wait, int, 0);
+MODULE_PARM_DESC(busy_wait,
+	"Max wait for mailbox in microseconds if busy (default=10)");
+
+/*
+ * number of sectors per IO command
+ */
+static unsigned int megaraid_max_sectors = MBOX_MAX_SECTORS;
+module_param_named(max_sectors, megaraid_max_sectors, int, 0);
+MODULE_PARM_DESC(max_sectors,
+	"Maximum number of sectors per IO command (default=128)");
+
+/*
+ * number of commands per logical unit
+ */
+static unsigned int megaraid_cmd_per_lun = MBOX_DEF_CMD_PER_LUN;
+module_param_named(cmd_per_lun, megaraid_cmd_per_lun, int, 0);
+MODULE_PARM_DESC(cmd_per_lun,
+	"Maximum number of commands per logical unit (default=64)");
+
+
+/*
+ * Fast driver load option, skip scanning for physical devices during load.
+ * This would result in non-disk devices being skipped during driver load
+ * time. These can be later added though, using /proc/scsi/scsi
+ */
+static unsigned int megaraid_fast_load;
+module_param_named(fast_load, megaraid_fast_load, int, 0);
+MODULE_PARM_DESC(fast_load,
+	"Faster loading of the driver, skips physical devices! (default=0)");
+
+
+/*
+ * mraid_debug level - threshold for amount of information to be displayed by
+ * the driver. This level can be changed through modules parameters, ioctl or
+ * sysfs/proc interface. By default, print the announcement messages only.
+ */
+int mraid_debug_level = CL_ANN;
+module_param_named(debug_level, mraid_debug_level, int, 0);
+MODULE_PARM_DESC(debug_level, "Debug level for driver (default=0)");
+
+/*
+ * PCI table for all supported controllers.
+ */
+static struct pci_device_id pci_id_table_g[] =  {
+	{
+		PCI_VENDOR_ID_DELL,
+		PCI_DEVICE_ID_PERC4_DI_DISCOVERY,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4_DI_DISCOVERY,
+	},
+	{
+		PCI_VENDOR_ID_LSI_LOGIC,
+		PCI_DEVICE_ID_PERC4_SC,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4_SC,
+	},
+	{
+		PCI_VENDOR_ID_LSI_LOGIC,
+		PCI_DEVICE_ID_PERC4_DC,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4_DC,
+	},
+	{
+		PCI_VENDOR_ID_LSI_LOGIC,
+		PCI_DEVICE_ID_VERDE,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+	},
+	{
+		PCI_VENDOR_ID_DELL,
+		PCI_DEVICE_ID_PERC4_DI_EVERGLADES,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4_DI_EVERGLADES,
+	},
+	{
+		PCI_VENDOR_ID_DELL,
+		PCI_DEVICE_ID_PERC4E_SI_BIGBEND,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4E_SI_BIGBEND,
+	},
+	{
+		PCI_VENDOR_ID_DELL,
+		PCI_DEVICE_ID_PERC4E_DI_KOBUK,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4E_DI_KOBUK,
+	},
+	{
+		PCI_VENDOR_ID_DELL,
+		PCI_DEVICE_ID_PERC4E_DI_CORVETTE,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4E_DI_CORVETTE,
+	},
+	{
+		PCI_VENDOR_ID_DELL,
+		PCI_DEVICE_ID_PERC4E_DI_EXPEDITION,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4E_DI_EXPEDITION,
+	},
+	{
+		PCI_VENDOR_ID_DELL,
+		PCI_DEVICE_ID_PERC4E_DI_GUADALUPE,
+		PCI_VENDOR_ID_DELL,
+		PCI_SUBSYS_ID_PERC4E_DI_GUADALUPE,
+	},
+	{
+		PCI_VENDOR_ID_LSI_LOGIC,
+		PCI_DEVICE_ID_DOBSON,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+	},
+	{
+		PCI_VENDOR_ID_AMI,
+		PCI_DEVICE_ID_AMI_MEGARAID3,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+	},
+	{
+		PCI_VENDOR_ID_LSI_LOGIC,
+		PCI_DEVICE_ID_AMI_MEGARAID3,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+	},
+	{
+		PCI_VENDOR_ID_LSI_LOGIC,
+		PCI_DEVICE_ID_LINDSAY,
+		PCI_ANY_ID,
+		PCI_ANY_ID,
+	},
+	{0}	/* Terminating entry */
+};
+MODULE_DEVICE_TABLE(pci, pci_id_table_g);
+
+
+static struct pci_driver megaraid_pci_driver = {
+	.name		= "megaraid",
+	.id_table	= pci_id_table_g,
+	.probe		= megaraid_probe_one,
+	.remove		= megaraid_detach_one,
+	.shutdown	= megaraid_mbox_shutdown,
+};
+
+
+
+// definitions for the device attributes for exporting logical drive number
+// for a scsi address (Host, Channel, Id, Lun)
+
+static DEVICE_ATTR_ADMIN_RO(megaraid_mbox_app_hndl);
+
+// Host template initializer for megaraid mbox sysfs device attributes
+static struct attribute *megaraid_shost_attrs[] = {
+	&dev_attr_megaraid_mbox_app_hndl.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(megaraid_shost);
+
+static DEVICE_ATTR_ADMIN_RO(megaraid_mbox_ld);
+
+// Host template initializer for megaraid mbox sysfs device attributes
+static struct attribute *megaraid_sdev_attrs[] = {
+	&dev_attr_megaraid_mbox_ld.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(megaraid_sdev);
+
+/*
+ * Scsi host template for megaraid unified driver
+ */
+static struct scsi_host_template megaraid_template_g = {
+	.module				= THIS_MODULE,
+	.name				= "LSI Logic MegaRAID driver",
+	.proc_name			= "megaraid",
+	.queuecommand			= megaraid_queue_command,
+	.eh_abort_handler		= megaraid_abort_handler,
+	.eh_host_reset_handler		= megaraid_reset_handler,
+	.change_queue_depth		= scsi_change_queue_depth,
+	.no_write_same			= 1,
+	.sdev_groups			= megaraid_sdev_groups,
+	.shost_groups			= megaraid_shost_groups,
+};
+
+
+/**
+ * megaraid_init - module load hook
+ *
+ * We register ourselves as hotplug enabled module and let PCI subsystem
+ * discover our adapters.
+ */
+static int __init
+megaraid_init(void)
+{
+	int	rval;
+
+	// Announce the driver version
+	con_log(CL_ANN, (KERN_INFO "megaraid: %s %s\n", MEGARAID_VERSION,
+		MEGARAID_EXT_VERSION));
+
+	// check validity of module parameters
+	if (megaraid_cmd_per_lun > MBOX_MAX_SCSI_CMDS) {
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid mailbox: max commands per lun reset to %d\n",
+			MBOX_MAX_SCSI_CMDS));
+
+		megaraid_cmd_per_lun = MBOX_MAX_SCSI_CMDS;
+	}
+
+
+	// register as a PCI hot-plug driver module
+	rval = pci_register_driver(&megaraid_pci_driver);
+	if (rval < 0) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: could not register hotplug support.\n"));
+	}
+
+	return rval;
+}
+
+
+/**
+ * megaraid_exit - driver unload entry point
+ *
+ * We simply unwrap the megaraid_init routine here.
+ */
+static void __exit
+megaraid_exit(void)
+{
+	con_log(CL_DLEVEL1, (KERN_NOTICE "megaraid: unloading framework\n"));
+
+	// unregister as PCI hotplug driver
+	pci_unregister_driver(&megaraid_pci_driver);
+
+	return;
+}
+
+
+/**
+ * megaraid_probe_one - PCI hotplug entry point
+ * @pdev	: handle to this controller's PCI configuration space
+ * @id		: pci device id of the class of controllers
+ *
+ * This routine should be called whenever a new adapter is detected by the
+ * PCI hotplug susbsystem.
+ */
+static int
+megaraid_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	adapter_t	*adapter;
+
+
+	// detected a new controller
+	con_log(CL_ANN, (KERN_INFO
+		"megaraid: probe new device %#4.04x:%#4.04x:%#4.04x:%#4.04x: ",
+		pdev->vendor, pdev->device, pdev->subsystem_vendor,
+		pdev->subsystem_device));
+
+	con_log(CL_ANN, ("bus %d:slot %d:func %d\n", pdev->bus->number,
+		PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn)));
+
+	if (pci_enable_device(pdev)) {
+		con_log(CL_ANN, (KERN_WARNING
+				"megaraid: pci_enable_device failed\n"));
+
+		return -ENODEV;
+	}
+
+	// Enable bus-mastering on this controller
+	pci_set_master(pdev);
+
+	// Allocate the per driver initialization structure
+	adapter = kzalloc(sizeof(adapter_t), GFP_KERNEL);
+
+	if (adapter == NULL) {
+		con_log(CL_ANN, (KERN_WARNING
+		"megaraid: out of memory, %s %d.\n", __func__, __LINE__));
+
+		goto out_probe_one;
+	}
+
+
+	// set up PCI related soft state and other pre-known parameters
+	adapter->unique_id	= pdev->bus->number << 8 | pdev->devfn;
+	adapter->irq		= pdev->irq;
+	adapter->pdev		= pdev;
+
+	atomic_set(&adapter->being_detached, 0);
+
+	// Setup the default DMA mask. This would be changed later on
+	// depending on hardware capabilities
+	if (dma_set_mask(&adapter->pdev->dev, DMA_BIT_MASK(32))) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: dma_set_mask failed:%d\n", __LINE__));
+
+		goto out_free_adapter;
+	}
+
+
+	// Initialize the synchronization lock for kernel and LLD
+	spin_lock_init(&adapter->lock);
+
+	// Initialize the command queues: the list of free SCBs and the list
+	// of pending SCBs.
+	INIT_LIST_HEAD(&adapter->kscb_pool);
+	spin_lock_init(SCSI_FREE_LIST_LOCK(adapter));
+
+	INIT_LIST_HEAD(&adapter->pend_list);
+	spin_lock_init(PENDING_LIST_LOCK(adapter));
+
+	INIT_LIST_HEAD(&adapter->completed_list);
+	spin_lock_init(COMPLETED_LIST_LOCK(adapter));
+
+
+	// Start the mailbox based controller
+	if (megaraid_init_mbox(adapter) != 0) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: mailbox adapter did not initialize\n"));
+
+		goto out_free_adapter;
+	}
+
+	// Register with LSI Common Management Module
+	if (megaraid_cmm_register(adapter) != 0) {
+
+		con_log(CL_ANN, (KERN_WARNING
+		"megaraid: could not register with management module\n"));
+
+		goto out_fini_mbox;
+	}
+
+	// setup adapter handle in PCI soft state
+	pci_set_drvdata(pdev, adapter);
+
+	// attach with scsi mid-layer
+	if (megaraid_io_attach(adapter) != 0) {
+
+		con_log(CL_ANN, (KERN_WARNING "megaraid: io attach failed\n"));
+
+		goto out_cmm_unreg;
+	}
+
+	return 0;
+
+out_cmm_unreg:
+	megaraid_cmm_unregister(adapter);
+out_fini_mbox:
+	megaraid_fini_mbox(adapter);
+out_free_adapter:
+	kfree(adapter);
+out_probe_one:
+	pci_disable_device(pdev);
+
+	return -ENODEV;
+}
+
+
+/**
+ * megaraid_detach_one - release framework resources and call LLD release routine
+ * @pdev	: handle for our PCI configuration space
+ *
+ * This routine is called during driver unload. We free all the allocated
+ * resources and call the corresponding LLD so that it can also release all
+ * its resources.
+ *
+ * This routine is also called from the PCI hotplug system.
+ */
+static void
+megaraid_detach_one(struct pci_dev *pdev)
+{
+	adapter_t		*adapter;
+	struct Scsi_Host	*host;
+
+
+	// Start a rollback on this adapter
+	adapter = pci_get_drvdata(pdev);
+
+	if (!adapter) {
+		con_log(CL_ANN, (KERN_CRIT
+		"megaraid: Invalid detach on %#4.04x:%#4.04x:%#4.04x:%#4.04x\n",
+			pdev->vendor, pdev->device, pdev->subsystem_vendor,
+			pdev->subsystem_device));
+
+		return;
+	}
+	else {
+		con_log(CL_ANN, (KERN_NOTICE
+		"megaraid: detaching device %#4.04x:%#4.04x:%#4.04x:%#4.04x\n",
+			pdev->vendor, pdev->device, pdev->subsystem_vendor,
+			pdev->subsystem_device));
+	}
+
+
+	host = adapter->host;
+
+	// do not allow any more requests from the management module for this
+	// adapter.
+	// FIXME: How do we account for the request which might still be
+	// pending with us?
+	atomic_set(&adapter->being_detached, 1);
+
+	// detach from the IO sub-system
+	megaraid_io_detach(adapter);
+
+	// Unregister from common management module
+	//
+	// FIXME: this must return success or failure for conditions if there
+	// is a command pending with LLD or not.
+	megaraid_cmm_unregister(adapter);
+
+	// finalize the mailbox based controller and release all resources
+	megaraid_fini_mbox(adapter);
+
+	kfree(adapter);
+
+	scsi_host_put(host);
+
+	pci_disable_device(pdev);
+
+	return;
+}
+
+
+/**
+ * megaraid_mbox_shutdown - PCI shutdown for megaraid HBA
+ * @pdev		: generic driver model device
+ *
+ * Shutdown notification, perform flush cache.
+ */
+static void
+megaraid_mbox_shutdown(struct pci_dev *pdev)
+{
+	adapter_t		*adapter = pci_get_drvdata(pdev);
+	static int		counter;
+
+	if (!adapter) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: null device in shutdown\n"));
+		return;
+	}
+
+	// flush caches now
+	con_log(CL_ANN, (KERN_INFO "megaraid: flushing adapter %d...",
+		counter++));
+
+	megaraid_mbox_flush_cache(adapter);
+
+	con_log(CL_ANN, ("done\n"));
+}
+
+
+/**
+ * megaraid_io_attach - attach a device with the IO subsystem
+ * @adapter		: controller's soft state
+ *
+ * Attach this device with the IO subsystem.
+ */
+static int
+megaraid_io_attach(adapter_t *adapter)
+{
+	struct Scsi_Host	*host;
+
+	// Initialize SCSI Host structure
+	host = scsi_host_alloc(&megaraid_template_g, 8);
+	if (!host) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid mbox: scsi_register failed\n"));
+
+		return -1;
+	}
+
+	SCSIHOST2ADAP(host)	= (caddr_t)adapter;
+	adapter->host		= host;
+
+	host->irq		= adapter->irq;
+	host->unique_id		= adapter->unique_id;
+	host->can_queue		= adapter->max_cmds;
+	host->this_id		= adapter->init_id;
+	host->sg_tablesize	= adapter->sglen;
+	host->max_sectors	= adapter->max_sectors;
+	host->cmd_per_lun	= adapter->cmd_per_lun;
+	host->max_channel	= adapter->max_channel;
+	host->max_id		= adapter->max_target;
+	host->max_lun		= adapter->max_lun;
+
+
+	// notify mid-layer about the new controller
+	if (scsi_add_host(host, &adapter->pdev->dev)) {
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid mbox: scsi_add_host failed\n"));
+
+		scsi_host_put(host);
+
+		return -1;
+	}
+
+	scsi_scan_host(host);
+
+	return 0;
+}
+
+
+/**
+ * megaraid_io_detach - detach a device from the IO subsystem
+ * @adapter		: controller's soft state
+ *
+ * Detach this device from the IO subsystem.
+ */
+static void
+megaraid_io_detach(adapter_t *adapter)
+{
+	struct Scsi_Host	*host;
+
+	con_log(CL_DLEVEL1, (KERN_INFO "megaraid: io detach\n"));
+
+	host = adapter->host;
+
+	scsi_remove_host(host);
+
+	return;
+}
+
+
+/*
+ * START: Mailbox Low Level Driver
+ *
+ * This is section specific to the single mailbox based controllers
+ */
+
+/**
+ * megaraid_init_mbox - initialize controller
+ * @adapter		: our soft state
+ *
+ * - Allocate 16-byte aligned mailbox memory for firmware handshake
+ * - Allocate controller's memory resources
+ * - Find out all initialization data
+ * - Allocate memory required for all the commands
+ * - Use internal library of FW routines, build up complete soft state
+ */
+static int
+megaraid_init_mbox(adapter_t *adapter)
+{
+	struct pci_dev		*pdev;
+	mraid_device_t		*raid_dev;
+	int			i;
+	uint32_t		magic64;
+
+
+	adapter->ito	= MBOX_TIMEOUT;
+	pdev		= adapter->pdev;
+
+	/*
+	 * Allocate and initialize the init data structure for mailbox
+	 * controllers
+	 */
+	raid_dev = kzalloc(sizeof(mraid_device_t), GFP_KERNEL);
+	if (raid_dev == NULL) return -1;
+
+
+	/*
+	 * Attach the adapter soft state to raid device soft state
+	 */
+	adapter->raid_device	= (caddr_t)raid_dev;
+	raid_dev->fast_load	= megaraid_fast_load;
+
+
+	// our baseport
+	raid_dev->baseport = pci_resource_start(pdev, 0);
+
+	if (pci_request_regions(pdev, "MegaRAID: LSI Logic Corporation") != 0) {
+
+		con_log(CL_ANN, (KERN_WARNING
+				"megaraid: mem region busy\n"));
+
+		goto out_free_raid_dev;
+	}
+
+	raid_dev->baseaddr = ioremap(raid_dev->baseport, 128);
+
+	if (!raid_dev->baseaddr) {
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: could not map hba memory\n") );
+
+		goto out_release_regions;
+	}
+
+	/* initialize the mutual exclusion lock for the mailbox */
+	spin_lock_init(&raid_dev->mailbox_lock);
+
+	/* allocate memory required for commands */
+	if (megaraid_alloc_cmd_packets(adapter) != 0)
+		goto out_iounmap;
+
+	/*
+	 * Issue SYNC cmd to flush the pending cmds in the adapter
+	 * and initialize its internal state
+	 */
+
+	if (megaraid_mbox_fire_sync_cmd(adapter))
+		con_log(CL_ANN, ("megaraid: sync cmd failed\n"));
+
+	/*
+	 * Setup the rest of the soft state using the library of
+	 * FW routines
+	 */
+
+	/* request IRQ and register the interrupt service routine */
+	if (request_irq(adapter->irq, megaraid_isr, IRQF_SHARED, "megaraid",
+		adapter)) {
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: Couldn't register IRQ %d!\n", adapter->irq));
+		goto out_alloc_cmds;
+
+	}
+
+	// Product info
+	if (megaraid_mbox_product_info(adapter) != 0)
+		goto out_free_irq;
+
+	// Do we support extended CDBs
+	adapter->max_cdb_sz = 10;
+	if (megaraid_mbox_extended_cdb(adapter) == 0) {
+		adapter->max_cdb_sz = 16;
+	}
+
+	/*
+	 * Do we support cluster environment, if we do, what is the initiator
+	 * id.
+	 * NOTE: In a non-cluster aware firmware environment, the LLD should
+	 * return 7 as initiator id.
+	 */
+	adapter->ha		= 0;
+	adapter->init_id	= -1;
+	if (megaraid_mbox_support_ha(adapter, &adapter->init_id) == 0) {
+		adapter->ha = 1;
+	}
+
+	/*
+	 * Prepare the device ids array to have the mapping between the kernel
+	 * device address and megaraid device address.
+	 * We export the physical devices on their actual addresses. The
+	 * logical drives are exported on a virtual SCSI channel
+	 */
+	megaraid_mbox_setup_device_map(adapter);
+
+	// If the firmware supports random deletion, update the device id map
+	if (megaraid_mbox_support_random_del(adapter)) {
+
+		// Change the logical drives numbers in device_ids array one
+		// slot in device_ids is reserved for target id, that's why
+		// "<=" below
+		for (i = 0; i <= MAX_LOGICAL_DRIVES_40LD; i++) {
+			adapter->device_ids[adapter->max_channel][i] += 0x80;
+		}
+		adapter->device_ids[adapter->max_channel][adapter->init_id] =
+			0xFF;
+
+		raid_dev->random_del_supported = 1;
+	}
+
+	/*
+	 * find out the maximum number of scatter-gather elements supported by
+	 * this firmware
+	 */
+	adapter->sglen = megaraid_mbox_get_max_sg(adapter);
+
+	// enumerate RAID and SCSI channels so that all devices on SCSI
+	// channels can later be exported, including disk devices
+	megaraid_mbox_enum_raid_scsi(adapter);
+
+	/*
+	 * Other parameters required by upper layer
+	 *
+	 * maximum number of sectors per IO command
+	 */
+	adapter->max_sectors = megaraid_max_sectors;
+
+	/*
+	 * number of queued commands per LUN.
+	 */
+	adapter->cmd_per_lun = megaraid_cmd_per_lun;
+
+	/*
+	 * Allocate resources required to issue FW calls, when sysfs is
+	 * accessed
+	 */
+	if (megaraid_sysfs_alloc_resources(adapter) != 0)
+		goto out_free_irq;
+
+	// Set the DMA mask to 64-bit. All supported controllers as capable of
+	// DMA in this range
+	pci_read_config_dword(adapter->pdev, PCI_CONF_AMISIG64, &magic64);
+
+	if (((magic64 == HBA_SIGNATURE_64_BIT) &&
+		((adapter->pdev->subsystem_device !=
+		PCI_SUBSYS_ID_MEGARAID_SATA_150_6) &&
+		(adapter->pdev->subsystem_device !=
+		PCI_SUBSYS_ID_MEGARAID_SATA_150_4))) ||
+		(adapter->pdev->vendor == PCI_VENDOR_ID_LSI_LOGIC &&
+		adapter->pdev->device == PCI_DEVICE_ID_VERDE) ||
+		(adapter->pdev->vendor == PCI_VENDOR_ID_LSI_LOGIC &&
+		adapter->pdev->device == PCI_DEVICE_ID_DOBSON) ||
+		(adapter->pdev->vendor == PCI_VENDOR_ID_LSI_LOGIC &&
+		adapter->pdev->device == PCI_DEVICE_ID_LINDSAY) ||
+		(adapter->pdev->vendor == PCI_VENDOR_ID_DELL &&
+		adapter->pdev->device == PCI_DEVICE_ID_PERC4_DI_EVERGLADES) ||
+		(adapter->pdev->vendor == PCI_VENDOR_ID_DELL &&
+		adapter->pdev->device == PCI_DEVICE_ID_PERC4E_DI_KOBUK)) {
+		if (dma_set_mask(&adapter->pdev->dev, DMA_BIT_MASK(64))) {
+			con_log(CL_ANN, (KERN_WARNING
+				"megaraid: DMA mask for 64-bit failed\n"));
+
+			if (dma_set_mask(&adapter->pdev->dev,
+						DMA_BIT_MASK(32))) {
+				con_log(CL_ANN, (KERN_WARNING
+					"megaraid: 32-bit DMA mask failed\n"));
+				goto out_free_sysfs_res;
+			}
+		}
+	}
+
+	// setup tasklet for DPC
+	tasklet_init(&adapter->dpc_h, megaraid_mbox_dpc,
+			(unsigned long)adapter);
+
+	con_log(CL_DLEVEL1, (KERN_INFO
+		"megaraid mbox hba successfully initialized\n"));
+
+	return 0;
+
+out_free_sysfs_res:
+	megaraid_sysfs_free_resources(adapter);
+out_free_irq:
+	free_irq(adapter->irq, adapter);
+out_alloc_cmds:
+	megaraid_free_cmd_packets(adapter);
+out_iounmap:
+	iounmap(raid_dev->baseaddr);
+out_release_regions:
+	pci_release_regions(pdev);
+out_free_raid_dev:
+	kfree(raid_dev);
+
+	return -1;
+}
+
+
+/**
+ * megaraid_fini_mbox - undo controller initialization
+ * @adapter		: our soft state
+ */
+static void
+megaraid_fini_mbox(adapter_t *adapter)
+{
+	mraid_device_t *raid_dev = ADAP2RAIDDEV(adapter);
+
+	// flush all caches
+	megaraid_mbox_flush_cache(adapter);
+
+	tasklet_kill(&adapter->dpc_h);
+
+	megaraid_sysfs_free_resources(adapter);
+
+	megaraid_free_cmd_packets(adapter);
+
+	free_irq(adapter->irq, adapter);
+
+	iounmap(raid_dev->baseaddr);
+
+	pci_release_regions(adapter->pdev);
+
+	kfree(raid_dev);
+
+	return;
+}
+
+
+/**
+ * megaraid_alloc_cmd_packets - allocate shared mailbox
+ * @adapter		: soft state of the raid controller
+ *
+ * Allocate and align the shared mailbox. This mailbox is used to issue
+ * all the commands. For IO based controllers, the mailbox is also registered
+ * with the FW. Allocate memory for all commands as well.
+ * This is our big allocator.
+ */
+static int
+megaraid_alloc_cmd_packets(adapter_t *adapter)
+{
+	mraid_device_t		*raid_dev = ADAP2RAIDDEV(adapter);
+	struct pci_dev		*pdev;
+	unsigned long		align;
+	scb_t			*scb;
+	mbox_ccb_t		*ccb;
+	struct mraid_pci_blk	*epthru_pci_blk;
+	struct mraid_pci_blk	*sg_pci_blk;
+	struct mraid_pci_blk	*mbox_pci_blk;
+	int			i;
+
+	pdev = adapter->pdev;
+
+	/*
+	 * Setup the mailbox
+	 * Allocate the common 16-byte aligned memory for the handshake
+	 * mailbox.
+	 */
+	raid_dev->una_mbox64 = dma_alloc_coherent(&adapter->pdev->dev,
+						  sizeof(mbox64_t),
+						  &raid_dev->una_mbox64_dma,
+						  GFP_KERNEL);
+
+	if (!raid_dev->una_mbox64) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: out of memory, %s %d\n", __func__,
+			__LINE__));
+		return -1;
+	}
+
+	/*
+	 * Align the mailbox at 16-byte boundary
+	 */
+	raid_dev->mbox	= &raid_dev->una_mbox64->mbox32;
+
+	raid_dev->mbox	= (mbox_t *)((((unsigned long)raid_dev->mbox) + 15) &
+				(~0UL ^ 0xFUL));
+
+	raid_dev->mbox64 = (mbox64_t *)(((unsigned long)raid_dev->mbox) - 8);
+
+	align = ((void *)raid_dev->mbox -
+			((void *)&raid_dev->una_mbox64->mbox32));
+
+	raid_dev->mbox_dma = (unsigned long)raid_dev->una_mbox64_dma + 8 +
+			align;
+
+	// Allocate memory for commands issued internally
+	adapter->ibuf = dma_alloc_coherent(&pdev->dev, MBOX_IBUF_SIZE,
+					   &adapter->ibuf_dma_h, GFP_KERNEL);
+	if (!adapter->ibuf) {
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: out of memory, %s %d\n", __func__,
+			__LINE__));
+
+		goto out_free_common_mbox;
+	}
+
+	// Allocate memory for our SCSI Command Blocks and their associated
+	// memory
+
+	/*
+	 * Allocate memory for the base list of scb. Later allocate memory for
+	 * CCBs and embedded components of each CCB and point the pointers in
+	 * scb to the allocated components
+	 * NOTE: The code to allocate SCB will be duplicated in all the LLD
+	 * since the calling routine does not yet know the number of available
+	 * commands.
+	 */
+	adapter->kscb_list = kcalloc(MBOX_MAX_SCSI_CMDS, sizeof(scb_t), GFP_KERNEL);
+
+	if (adapter->kscb_list == NULL) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: out of memory, %s %d\n", __func__,
+			__LINE__));
+		goto out_free_ibuf;
+	}
+
+	// memory allocation for our command packets
+	if (megaraid_mbox_setup_dma_pools(adapter) != 0) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: out of memory, %s %d\n", __func__,
+			__LINE__));
+		goto out_free_scb_list;
+	}
+
+	// Adjust the scb pointers and link in the free pool
+	epthru_pci_blk	= raid_dev->epthru_pool;
+	sg_pci_blk	= raid_dev->sg_pool;
+	mbox_pci_blk	= raid_dev->mbox_pool;
+
+	for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
+		scb			= adapter->kscb_list + i;
+		ccb			= raid_dev->ccb_list + i;
+
+		ccb->mbox	= (mbox_t *)(mbox_pci_blk[i].vaddr + 16);
+		ccb->raw_mbox	= (uint8_t *)ccb->mbox;
+		ccb->mbox64	= (mbox64_t *)(mbox_pci_blk[i].vaddr + 8);
+		ccb->mbox_dma_h	= (unsigned long)mbox_pci_blk[i].dma_addr + 16;
+
+		// make sure the mailbox is aligned properly
+		if (ccb->mbox_dma_h & 0x0F) {
+			con_log(CL_ANN, (KERN_CRIT
+				"megaraid mbox: not aligned on 16-bytes\n"));
+
+			goto out_teardown_dma_pools;
+		}
+
+		ccb->epthru		= (mraid_epassthru_t *)
+						epthru_pci_blk[i].vaddr;
+		ccb->epthru_dma_h	= epthru_pci_blk[i].dma_addr;
+		ccb->pthru		= (mraid_passthru_t *)ccb->epthru;
+		ccb->pthru_dma_h	= ccb->epthru_dma_h;
+
+
+		ccb->sgl64		= (mbox_sgl64 *)sg_pci_blk[i].vaddr;
+		ccb->sgl_dma_h		= sg_pci_blk[i].dma_addr;
+		ccb->sgl32		= (mbox_sgl32 *)ccb->sgl64;
+
+		scb->ccb		= (caddr_t)ccb;
+		scb->gp			= 0;
+
+		scb->sno		= i;	// command index
+
+		scb->scp		= NULL;
+		scb->state		= SCB_FREE;
+		scb->dma_direction	= DMA_NONE;
+		scb->dma_type		= MRAID_DMA_NONE;
+		scb->dev_channel	= -1;
+		scb->dev_target		= -1;
+
+		// put scb in the free pool
+		list_add_tail(&scb->list, &adapter->kscb_pool);
+	}
+
+	return 0;
+
+out_teardown_dma_pools:
+	megaraid_mbox_teardown_dma_pools(adapter);
+out_free_scb_list:
+	kfree(adapter->kscb_list);
+out_free_ibuf:
+	dma_free_coherent(&pdev->dev, MBOX_IBUF_SIZE, (void *)adapter->ibuf,
+		adapter->ibuf_dma_h);
+out_free_common_mbox:
+	dma_free_coherent(&adapter->pdev->dev, sizeof(mbox64_t),
+		(caddr_t)raid_dev->una_mbox64, raid_dev->una_mbox64_dma);
+
+	return -1;
+}
+
+
+/**
+ * megaraid_free_cmd_packets - free memory
+ * @adapter		: soft state of the raid controller
+ *
+ * Release memory resources allocated for commands.
+ */
+static void
+megaraid_free_cmd_packets(adapter_t *adapter)
+{
+	mraid_device_t *raid_dev = ADAP2RAIDDEV(adapter);
+
+	megaraid_mbox_teardown_dma_pools(adapter);
+
+	kfree(adapter->kscb_list);
+
+	dma_free_coherent(&adapter->pdev->dev, MBOX_IBUF_SIZE,
+		(void *)adapter->ibuf, adapter->ibuf_dma_h);
+
+	dma_free_coherent(&adapter->pdev->dev, sizeof(mbox64_t),
+		(caddr_t)raid_dev->una_mbox64, raid_dev->una_mbox64_dma);
+	return;
+}
+
+
+/**
+ * megaraid_mbox_setup_dma_pools - setup dma pool for command packets
+ * @adapter		: HBA soft state
+ *
+ * Setup the dma pools for mailbox, passthru and extended passthru structures,
+ * and scatter-gather lists.
+ */
+static int
+megaraid_mbox_setup_dma_pools(adapter_t *adapter)
+{
+	mraid_device_t		*raid_dev = ADAP2RAIDDEV(adapter);
+	struct mraid_pci_blk	*epthru_pci_blk;
+	struct mraid_pci_blk	*sg_pci_blk;
+	struct mraid_pci_blk	*mbox_pci_blk;
+	int			i;
+
+
+
+	// Allocate memory for 16-bytes aligned mailboxes
+	raid_dev->mbox_pool_handle = dma_pool_create("megaraid mbox pool",
+						&adapter->pdev->dev,
+						sizeof(mbox64_t) + 16,
+						16, 0);
+
+	if (raid_dev->mbox_pool_handle == NULL) {
+		goto fail_setup_dma_pool;
+	}
+
+	mbox_pci_blk = raid_dev->mbox_pool;
+	for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
+		mbox_pci_blk[i].vaddr = dma_pool_alloc(
+						raid_dev->mbox_pool_handle,
+						GFP_KERNEL,
+						&mbox_pci_blk[i].dma_addr);
+		if (!mbox_pci_blk[i].vaddr) {
+			goto fail_setup_dma_pool;
+		}
+	}
+
+	/*
+	 * Allocate memory for each embedded passthru strucuture pointer
+	 * Request for a 128 bytes aligned structure for each passthru command
+	 * structure
+	 * Since passthru and extended passthru commands are exclusive, they
+	 * share common memory pool. Passthru structures piggyback on memory
+	 * allocated to extended passthru since passthru is smaller of the two
+	 */
+	raid_dev->epthru_pool_handle = dma_pool_create("megaraid mbox pthru",
+			&adapter->pdev->dev, sizeof(mraid_epassthru_t), 128, 0);
+
+	if (raid_dev->epthru_pool_handle == NULL) {
+		goto fail_setup_dma_pool;
+	}
+
+	epthru_pci_blk = raid_dev->epthru_pool;
+	for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
+		epthru_pci_blk[i].vaddr = dma_pool_alloc(
+						raid_dev->epthru_pool_handle,
+						GFP_KERNEL,
+						&epthru_pci_blk[i].dma_addr);
+		if (!epthru_pci_blk[i].vaddr) {
+			goto fail_setup_dma_pool;
+		}
+	}
+
+
+	// Allocate memory for each scatter-gather list. Request for 512 bytes
+	// alignment for each sg list
+	raid_dev->sg_pool_handle = dma_pool_create("megaraid mbox sg",
+					&adapter->pdev->dev,
+					sizeof(mbox_sgl64) * MBOX_MAX_SG_SIZE,
+					512, 0);
+
+	if (raid_dev->sg_pool_handle == NULL) {
+		goto fail_setup_dma_pool;
+	}
+
+	sg_pci_blk = raid_dev->sg_pool;
+	for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
+		sg_pci_blk[i].vaddr = dma_pool_alloc(
+						raid_dev->sg_pool_handle,
+						GFP_KERNEL,
+						&sg_pci_blk[i].dma_addr);
+		if (!sg_pci_blk[i].vaddr) {
+			goto fail_setup_dma_pool;
+		}
+	}
+
+	return 0;
+
+fail_setup_dma_pool:
+	megaraid_mbox_teardown_dma_pools(adapter);
+	return -1;
+}
+
+
+/**
+ * megaraid_mbox_teardown_dma_pools - teardown dma pools for command packets
+ * @adapter		: HBA soft state
+ *
+ * Teardown the dma pool for mailbox, passthru and extended passthru
+ * structures, and scatter-gather lists.
+ */
+static void
+megaraid_mbox_teardown_dma_pools(adapter_t *adapter)
+{
+	mraid_device_t		*raid_dev = ADAP2RAIDDEV(adapter);
+	struct mraid_pci_blk	*epthru_pci_blk;
+	struct mraid_pci_blk	*sg_pci_blk;
+	struct mraid_pci_blk	*mbox_pci_blk;
+	int			i;
+
+
+	sg_pci_blk = raid_dev->sg_pool;
+	for (i = 0; i < MBOX_MAX_SCSI_CMDS && sg_pci_blk[i].vaddr; i++) {
+		dma_pool_free(raid_dev->sg_pool_handle, sg_pci_blk[i].vaddr,
+			sg_pci_blk[i].dma_addr);
+	}
+	dma_pool_destroy(raid_dev->sg_pool_handle);
+
+
+	epthru_pci_blk = raid_dev->epthru_pool;
+	for (i = 0; i < MBOX_MAX_SCSI_CMDS && epthru_pci_blk[i].vaddr; i++) {
+		dma_pool_free(raid_dev->epthru_pool_handle,
+			epthru_pci_blk[i].vaddr, epthru_pci_blk[i].dma_addr);
+	}
+	dma_pool_destroy(raid_dev->epthru_pool_handle);
+
+
+	mbox_pci_blk = raid_dev->mbox_pool;
+	for (i = 0; i < MBOX_MAX_SCSI_CMDS && mbox_pci_blk[i].vaddr; i++) {
+		dma_pool_free(raid_dev->mbox_pool_handle,
+			mbox_pci_blk[i].vaddr, mbox_pci_blk[i].dma_addr);
+	}
+	dma_pool_destroy(raid_dev->mbox_pool_handle);
+
+	return;
+}
+
+
+/**
+ * megaraid_alloc_scb - detach and return a scb from the free list
+ * @adapter	: controller's soft state
+ * @scp		: pointer to the scsi command to be executed
+ *
+ * Return the scb from the head of the free list. %NULL if there are none
+ * available.
+ */
+static scb_t *
+megaraid_alloc_scb(adapter_t *adapter, struct scsi_cmnd *scp)
+{
+	struct list_head	*head = &adapter->kscb_pool;
+	scb_t			*scb = NULL;
+	unsigned long		flags;
+
+	// detach scb from free pool
+	spin_lock_irqsave(SCSI_FREE_LIST_LOCK(adapter), flags);
+
+	if (list_empty(head)) {
+		spin_unlock_irqrestore(SCSI_FREE_LIST_LOCK(adapter), flags);
+		return NULL;
+	}
+
+	scb = list_entry(head->next, scb_t, list);
+	list_del_init(&scb->list);
+
+	spin_unlock_irqrestore(SCSI_FREE_LIST_LOCK(adapter), flags);
+
+	scb->state	= SCB_ACTIVE;
+	scb->scp	= scp;
+	scb->dma_type	= MRAID_DMA_NONE;
+
+	return scb;
+}
+
+
+/**
+ * megaraid_dealloc_scb - return the scb to the free pool
+ * @adapter	: controller's soft state
+ * @scb		: scb to be freed
+ *
+ * Return the scb back to the free list of scbs. The caller must 'flush' the
+ * SCB before calling us. E.g., performing pci_unamp and/or pci_sync etc.
+ * NOTE NOTE: Make sure the scb is not on any list before calling this
+ * routine.
+ */
+static inline void
+megaraid_dealloc_scb(adapter_t *adapter, scb_t *scb)
+{
+	unsigned long		flags;
+
+	// put scb in the free pool
+	scb->state	= SCB_FREE;
+	scb->scp	= NULL;
+	spin_lock_irqsave(SCSI_FREE_LIST_LOCK(adapter), flags);
+
+	list_add(&scb->list, &adapter->kscb_pool);
+
+	spin_unlock_irqrestore(SCSI_FREE_LIST_LOCK(adapter), flags);
+
+	return;
+}
+
+
+/**
+ * megaraid_mbox_mksgl - make the scatter-gather list
+ * @adapter	: controller's soft state
+ * @scb		: scsi control block
+ *
+ * Prepare the scatter-gather list.
+ */
+static int
+megaraid_mbox_mksgl(adapter_t *adapter, scb_t *scb)
+{
+	struct scatterlist	*sgl;
+	mbox_ccb_t		*ccb;
+	struct scsi_cmnd	*scp;
+	int			sgcnt;
+	int			i;
+
+
+	scp	= scb->scp;
+	ccb	= (mbox_ccb_t *)scb->ccb;
+
+	sgcnt = scsi_dma_map(scp);
+	BUG_ON(sgcnt < 0 || sgcnt > adapter->sglen);
+
+	// no mapping required if no data to be transferred
+	if (!sgcnt)
+		return 0;
+
+	scb->dma_type = MRAID_DMA_WSG;
+
+	scsi_for_each_sg(scp, sgl, sgcnt, i) {
+		ccb->sgl64[i].address	= sg_dma_address(sgl);
+		ccb->sgl64[i].length	= sg_dma_len(sgl);
+	}
+
+	// Return count of SG nodes
+	return sgcnt;
+}
+
+
+/**
+ * mbox_post_cmd - issue a mailbox command
+ * @adapter	: controller's soft state
+ * @scb		: command to be issued
+ *
+ * Post the command to the controller if mailbox is available.
+ */
+static int
+mbox_post_cmd(adapter_t *adapter, scb_t *scb)
+{
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+	mbox64_t	*mbox64;
+	mbox_t		*mbox;
+	mbox_ccb_t	*ccb;
+	unsigned long	flags;
+	unsigned int	i = 0;
+
+
+	ccb	= (mbox_ccb_t *)scb->ccb;
+	mbox	= raid_dev->mbox;
+	mbox64	= raid_dev->mbox64;
+
+	/*
+	 * Check for busy mailbox. If it is, return failure - the caller
+	 * should retry later.
+	 */
+	spin_lock_irqsave(MAILBOX_LOCK(raid_dev), flags);
+
+	if (unlikely(mbox->busy)) {
+		do {
+			udelay(1);
+			i++;
+			rmb();
+		} while(mbox->busy && (i < max_mbox_busy_wait));
+
+		if (mbox->busy) {
+
+			spin_unlock_irqrestore(MAILBOX_LOCK(raid_dev), flags);
+
+			return -1;
+		}
+	}
+
+
+	// Copy this command's mailbox data into "adapter's" mailbox
+	memcpy((caddr_t)mbox64, (caddr_t)ccb->mbox64, 22);
+	mbox->cmdid = scb->sno;
+
+	adapter->outstanding_cmds++;
+
+	mbox->busy	= 1;	// Set busy
+	mbox->poll	= 0;
+	mbox->ack	= 0;
+	wmb();
+
+	WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);
+
+	spin_unlock_irqrestore(MAILBOX_LOCK(raid_dev), flags);
+
+	return 0;
+}
+
+
+/**
+ * megaraid_queue_command_lck - generic queue entry point for all LLDs
+ * @scp		: pointer to the scsi command to be executed
+ *
+ * Queue entry point for mailbox based controllers.
+ */
+static int megaraid_queue_command_lck(struct scsi_cmnd *scp)
+{
+	void (*done)(struct scsi_cmnd *) = scsi_done;
+	adapter_t	*adapter;
+	scb_t		*scb;
+	int		if_busy;
+
+	adapter		= SCP2ADAPTER(scp);
+	scp->result	= 0;
+
+	/*
+	 * Allocate and build a SCB request
+	 * if_busy flag will be set if megaraid_mbox_build_cmd() command could
+	 * not allocate scb. We will return non-zero status in that case.
+	 * NOTE: scb can be null even though certain commands completed
+	 * successfully, e.g., MODE_SENSE and TEST_UNIT_READY, it would
+	 * return 0 in that case, and we would do the callback right away.
+	 */
+	if_busy	= 0;
+	scb = megaraid_mbox_build_cmd(adapter, scp, &if_busy);
+	if (!scb) {	// command already completed
+		done(scp);
+		return 0;
+	}
+
+	megaraid_mbox_runpendq(adapter, scb);
+	return if_busy;
+}
+
+static DEF_SCSI_QCMD(megaraid_queue_command)
+
+/**
+ * megaraid_mbox_build_cmd - transform the mid-layer scsi commands
+ * @adapter	: controller's soft state
+ * @scp		: mid-layer scsi command pointer
+ * @busy	: set if request could not be completed because of lack of
+ *		resources
+ *
+ * Transform the mid-layer scsi command to megaraid firmware lingua.
+ * Convert the command issued by mid-layer to format understood by megaraid
+ * firmware. We also complete certain commands without sending them to firmware.
+ */
+static scb_t *
+megaraid_mbox_build_cmd(adapter_t *adapter, struct scsi_cmnd *scp, int *busy)
+{
+	mraid_device_t		*rdev = ADAP2RAIDDEV(adapter);
+	int			channel;
+	int			target;
+	int			islogical;
+	mbox_ccb_t		*ccb;
+	mraid_passthru_t	*pthru;
+	mbox64_t		*mbox64;
+	mbox_t			*mbox;
+	scb_t			*scb;
+	char			skip[] = "skipping";
+	char			scan[] = "scanning";
+	char			*ss;
+
+
+	/*
+	 * Get the appropriate device map for the device this command is
+	 * intended for
+	 */
+	MRAID_GET_DEVICE_MAP(adapter, scp, channel, target, islogical);
+
+	/*
+	 * Logical drive commands
+	 */
+	if (islogical) {
+		switch (scp->cmnd[0]) {
+		case TEST_UNIT_READY:
+			/*
+			 * Do we support clustering and is the support enabled
+			 * If no, return success always
+			 */
+			if (!adapter->ha) {
+				scp->result = (DID_OK << 16);
+				return NULL;
+			}
+
+			if (!(scb = megaraid_alloc_scb(adapter, scp))) {
+				scp->result = (DID_ERROR << 16);
+				*busy = 1;
+				return NULL;
+			}
+
+			scb->dma_direction	= scp->sc_data_direction;
+			scb->dev_channel	= 0xFF;
+			scb->dev_target		= target;
+			ccb			= (mbox_ccb_t *)scb->ccb;
+
+			/*
+			 * The command id will be provided by the command
+			 * issuance routine
+			 */
+			ccb->raw_mbox[0]	= CLUSTER_CMD;
+			ccb->raw_mbox[2]	= RESERVATION_STATUS;
+			ccb->raw_mbox[3]	= target;
+
+			return scb;
+
+		case MODE_SENSE:
+		{
+			struct scatterlist	*sgl;
+			caddr_t			vaddr;
+
+			sgl = scsi_sglist(scp);
+			if (sg_page(sgl)) {
+				vaddr = (caddr_t) sg_virt(&sgl[0]);
+
+				memset(vaddr, 0, scp->cmnd[4]);
+			}
+			else {
+				con_log(CL_ANN, (KERN_WARNING
+						 "megaraid mailbox: invalid sg:%d\n",
+						 __LINE__));
+			}
+		}
+		scp->result = (DID_OK << 16);
+		return NULL;
+
+		case INQUIRY:
+			/*
+			 * Display the channel scan for logical drives
+			 * Do not display scan for a channel if already done.
+			 */
+			if (!(rdev->last_disp & (1L << SCP2CHANNEL(scp)))) {
+
+				con_log(CL_ANN, (KERN_INFO
+					"scsi[%d]: scanning scsi channel %d",
+					adapter->host->host_no,
+					SCP2CHANNEL(scp)));
+
+				con_log(CL_ANN, (
+					" [virtual] for logical drives\n"));
+
+				rdev->last_disp |= (1L << SCP2CHANNEL(scp));
+			}
+
+			if (scp->cmnd[1] & MEGA_SCSI_INQ_EVPD) {
+				scsi_build_sense(scp, 0, ILLEGAL_REQUEST,
+						 MEGA_INVALID_FIELD_IN_CDB, 0);
+				return NULL;
+			}
+
+			fallthrough;
+
+		case READ_CAPACITY:
+			/*
+			 * Do not allow LUN > 0 for logical drives and
+			 * requests for more than 40 logical drives
+			 */
+			if (SCP2LUN(scp)) {
+				scp->result = (DID_BAD_TARGET << 16);
+				return NULL;
+			}
+			if ((target % 0x80) >= MAX_LOGICAL_DRIVES_40LD) {
+				scp->result = (DID_BAD_TARGET << 16);
+				return NULL;
+			}
+
+
+			/* Allocate a SCB and initialize passthru */
+			if (!(scb = megaraid_alloc_scb(adapter, scp))) {
+				scp->result = (DID_ERROR << 16);
+				*busy = 1;
+				return NULL;
+			}
+
+			ccb			= (mbox_ccb_t *)scb->ccb;
+			scb->dev_channel	= 0xFF;
+			scb->dev_target		= target;
+			pthru			= ccb->pthru;
+			mbox			= ccb->mbox;
+			mbox64			= ccb->mbox64;
+
+			pthru->timeout		= 0;
+			pthru->ars		= 1;
+			pthru->reqsenselen	= 14;
+			pthru->islogical	= 1;
+			pthru->logdrv		= target;
+			pthru->cdblen		= scp->cmd_len;
+			memcpy(pthru->cdb, scp->cmnd, scp->cmd_len);
+
+			mbox->cmd		= MBOXCMD_PASSTHRU64;
+			scb->dma_direction	= scp->sc_data_direction;
+
+			pthru->dataxferlen	= scsi_bufflen(scp);
+			pthru->dataxferaddr	= ccb->sgl_dma_h;
+			pthru->numsge		= megaraid_mbox_mksgl(adapter,
+							scb);
+
+			mbox->xferaddr		= 0xFFFFFFFF;
+			mbox64->xferaddr_lo	= (uint32_t )ccb->pthru_dma_h;
+			mbox64->xferaddr_hi	= 0;
+
+			return scb;
+
+		case READ_6:
+		case WRITE_6:
+		case READ_10:
+		case WRITE_10:
+		case READ_12:
+		case WRITE_12:
+
+			/*
+			 * Allocate a SCB and initialize mailbox
+			 */
+			if (!(scb = megaraid_alloc_scb(adapter, scp))) {
+				scp->result = (DID_ERROR << 16);
+				*busy = 1;
+				return NULL;
+			}
+			ccb			= (mbox_ccb_t *)scb->ccb;
+			scb->dev_channel	= 0xFF;
+			scb->dev_target		= target;
+			mbox			= ccb->mbox;
+			mbox64			= ccb->mbox64;
+			mbox->logdrv		= target;
+
+			/*
+			 * A little HACK: 2nd bit is zero for all scsi read
+			 * commands and is set for all scsi write commands
+			 */
+			mbox->cmd = (scp->cmnd[0] & 0x02) ?  MBOXCMD_LWRITE64:
+					MBOXCMD_LREAD64 ;
+
+			/*
+			 * 6-byte READ(0x08) or WRITE(0x0A) cdb
+			 */
+			if (scp->cmd_len == 6) {
+				mbox->numsectors = (uint32_t)scp->cmnd[4];
+				mbox->lba =
+					((uint32_t)scp->cmnd[1] << 16)	|
+					((uint32_t)scp->cmnd[2] << 8)	|
+					(uint32_t)scp->cmnd[3];
+
+				mbox->lba &= 0x1FFFFF;
+			}
+
+			/*
+			 * 10-byte READ(0x28) or WRITE(0x2A) cdb
+			 */
+			else if (scp->cmd_len == 10) {
+				mbox->numsectors =
+					(uint32_t)scp->cmnd[8] |
+					((uint32_t)scp->cmnd[7] << 8);
+				mbox->lba =
+					((uint32_t)scp->cmnd[2] << 24) |
+					((uint32_t)scp->cmnd[3] << 16) |
+					((uint32_t)scp->cmnd[4] << 8) |
+					(uint32_t)scp->cmnd[5];
+			}
+
+			/*
+			 * 12-byte READ(0xA8) or WRITE(0xAA) cdb
+			 */
+			else if (scp->cmd_len == 12) {
+				mbox->lba =
+					((uint32_t)scp->cmnd[2] << 24) |
+					((uint32_t)scp->cmnd[3] << 16) |
+					((uint32_t)scp->cmnd[4] << 8) |
+					(uint32_t)scp->cmnd[5];
+
+				mbox->numsectors =
+					((uint32_t)scp->cmnd[6] << 24) |
+					((uint32_t)scp->cmnd[7] << 16) |
+					((uint32_t)scp->cmnd[8] << 8) |
+					(uint32_t)scp->cmnd[9];
+			}
+			else {
+				con_log(CL_ANN, (KERN_WARNING
+					"megaraid: unsupported CDB length\n"));
+
+				megaraid_dealloc_scb(adapter, scb);
+
+				scp->result = (DID_ERROR << 16);
+				return NULL;
+			}
+
+			scb->dma_direction = scp->sc_data_direction;
+
+			// Calculate Scatter-Gather info
+			mbox64->xferaddr_lo	= (uint32_t )ccb->sgl_dma_h;
+			mbox->numsge		= megaraid_mbox_mksgl(adapter,
+							scb);
+			mbox->xferaddr		= 0xFFFFFFFF;
+			mbox64->xferaddr_hi	= 0;
+
+			return scb;
+
+		case RESERVE:
+		case RELEASE:
+			/*
+			 * Do we support clustering and is the support enabled
+			 */
+			if (!adapter->ha) {
+				scp->result = (DID_BAD_TARGET << 16);
+				return NULL;
+			}
+
+			/*
+			 * Allocate a SCB and initialize mailbox
+			 */
+			if (!(scb = megaraid_alloc_scb(adapter, scp))) {
+				scp->result = (DID_ERROR << 16);
+				*busy = 1;
+				return NULL;
+			}
+
+			ccb			= (mbox_ccb_t *)scb->ccb;
+			scb->dev_channel	= 0xFF;
+			scb->dev_target		= target;
+			ccb->raw_mbox[0]	= CLUSTER_CMD;
+			ccb->raw_mbox[2]	=  (scp->cmnd[0] == RESERVE) ?
+						RESERVE_LD : RELEASE_LD;
+
+			ccb->raw_mbox[3]	= target;
+			scb->dma_direction	= scp->sc_data_direction;
+
+			return scb;
+
+		default:
+			scp->result = (DID_BAD_TARGET << 16);
+			return NULL;
+		}
+	}
+	else { // Passthru device commands
+
+		// Do not allow access to target id > 15 or LUN > 7
+		if (target > 15 || SCP2LUN(scp) > 7) {
+			scp->result = (DID_BAD_TARGET << 16);
+			return NULL;
+		}
+
+		// if fast load option was set and scan for last device is
+		// over, reset the fast_load flag so that during a possible
+		// next scan, devices can be made available
+		if (rdev->fast_load && (target == 15) &&
+			(SCP2CHANNEL(scp) == adapter->max_channel -1)) {
+
+			con_log(CL_ANN, (KERN_INFO
+			"megaraid[%d]: physical device scan re-enabled\n",
+				adapter->host->host_no));
+			rdev->fast_load = 0;
+		}
+
+		/*
+		 * Display the channel scan for physical devices
+		 */
+		if (!(rdev->last_disp & (1L << SCP2CHANNEL(scp)))) {
+
+			ss = rdev->fast_load ? skip : scan;
+
+			con_log(CL_ANN, (KERN_INFO
+				"scsi[%d]: %s scsi channel %d [Phy %d]",
+				adapter->host->host_no, ss, SCP2CHANNEL(scp),
+				channel));
+
+			con_log(CL_ANN, (
+				" for non-raid devices\n"));
+
+			rdev->last_disp |= (1L << SCP2CHANNEL(scp));
+		}
+
+		// disable channel sweep if fast load option given
+		if (rdev->fast_load) {
+			scp->result = (DID_BAD_TARGET << 16);
+			return NULL;
+		}
+
+		// Allocate a SCB and initialize passthru
+		if (!(scb = megaraid_alloc_scb(adapter, scp))) {
+			scp->result = (DID_ERROR << 16);
+			*busy = 1;
+			return NULL;
+		}
+
+		ccb			= (mbox_ccb_t *)scb->ccb;
+		scb->dev_channel	= channel;
+		scb->dev_target		= target;
+		scb->dma_direction	= scp->sc_data_direction;
+		mbox			= ccb->mbox;
+		mbox64			= ccb->mbox64;
+
+		// Does this firmware support extended CDBs
+		if (adapter->max_cdb_sz == 16) {
+			mbox->cmd		= MBOXCMD_EXTPTHRU;
+
+			megaraid_mbox_prepare_epthru(adapter, scb, scp);
+
+			mbox64->xferaddr_lo	= (uint32_t)ccb->epthru_dma_h;
+			mbox64->xferaddr_hi	= 0;
+			mbox->xferaddr		= 0xFFFFFFFF;
+		}
+		else {
+			mbox->cmd = MBOXCMD_PASSTHRU64;
+
+			megaraid_mbox_prepare_pthru(adapter, scb, scp);
+
+			mbox64->xferaddr_lo	= (uint32_t)ccb->pthru_dma_h;
+			mbox64->xferaddr_hi	= 0;
+			mbox->xferaddr		= 0xFFFFFFFF;
+		}
+		return scb;
+	}
+
+	// NOT REACHED
+}
+
+
+/**
+ * megaraid_mbox_runpendq - execute commands queued in the pending queue
+ * @adapter	: controller's soft state
+ * @scb_q	: SCB to be queued in the pending list
+ *
+ * Scan the pending list for commands which are not yet issued and try to
+ * post to the controller. The SCB can be a null pointer, which would indicate
+ * no SCB to be queue, just try to execute the ones in the pending list.
+ *
+ * NOTE: We do not actually traverse the pending list. The SCBs are plucked
+ * out from the head of the pending list. If it is successfully issued, the
+ * next SCB is at the head now.
+ */
+static void
+megaraid_mbox_runpendq(adapter_t *adapter, scb_t *scb_q)
+{
+	scb_t			*scb;
+	unsigned long		flags;
+
+	spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);
+
+	if (scb_q) {
+		scb_q->state = SCB_PENDQ;
+		list_add_tail(&scb_q->list, &adapter->pend_list);
+	}
+
+	// if the adapter in not in quiescent mode, post the commands to FW
+	if (adapter->quiescent) {
+		spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);
+		return;
+	}
+
+	while (!list_empty(&adapter->pend_list)) {
+
+		assert_spin_locked(PENDING_LIST_LOCK(adapter));
+
+		scb = list_entry(adapter->pend_list.next, scb_t, list);
+
+		// remove the scb from the pending list and try to
+		// issue. If we are unable to issue it, put back in
+		// the pending list and return
+
+		list_del_init(&scb->list);
+
+		spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);
+
+		// if mailbox was busy, return SCB back to pending
+		// list. Make sure to add at the head, since that's
+		// where it would have been removed from
+
+		scb->state = SCB_ISSUED;
+
+		if (mbox_post_cmd(adapter, scb) != 0) {
+
+			spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);
+
+			scb->state = SCB_PENDQ;
+
+			list_add(&scb->list, &adapter->pend_list);
+
+			spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter),
+				flags);
+
+			return;
+		}
+
+		spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);
+	}
+
+	spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);
+
+
+	return;
+}
+
+
+/**
+ * megaraid_mbox_prepare_pthru - prepare a command for physical devices
+ * @adapter	: pointer to controller's soft state
+ * @scb		: scsi control block
+ * @scp		: scsi command from the mid-layer
+ *
+ * Prepare a command for the scsi physical devices.
+ */
+static void
+megaraid_mbox_prepare_pthru(adapter_t *adapter, scb_t *scb,
+		struct scsi_cmnd *scp)
+{
+	mbox_ccb_t		*ccb;
+	mraid_passthru_t	*pthru;
+	uint8_t			channel;
+	uint8_t			target;
+
+	ccb	= (mbox_ccb_t *)scb->ccb;
+	pthru	= ccb->pthru;
+	channel	= scb->dev_channel;
+	target	= scb->dev_target;
+
+	// 0=6sec, 1=60sec, 2=10min, 3=3hrs, 4=NO timeout
+	pthru->timeout		= 4;	
+	pthru->ars		= 1;
+	pthru->islogical	= 0;
+	pthru->channel		= 0;
+	pthru->target		= (channel << 4) | target;
+	pthru->logdrv		= SCP2LUN(scp);
+	pthru->reqsenselen	= 14;
+	pthru->cdblen		= scp->cmd_len;
+
+	memcpy(pthru->cdb, scp->cmnd, scp->cmd_len);
+
+	if (scsi_bufflen(scp)) {
+		pthru->dataxferlen	= scsi_bufflen(scp);
+		pthru->dataxferaddr	= ccb->sgl_dma_h;
+		pthru->numsge		= megaraid_mbox_mksgl(adapter, scb);
+	}
+	else {
+		pthru->dataxferaddr	= 0;
+		pthru->dataxferlen	= 0;
+		pthru->numsge		= 0;
+	}
+	return;
+}
+
+
+/**
+ * megaraid_mbox_prepare_epthru - prepare a command for physical devices
+ * @adapter	: pointer to controller's soft state
+ * @scb		: scsi control block
+ * @scp		: scsi command from the mid-layer
+ *
+ * Prepare a command for the scsi physical devices. This routine prepares
+ * commands for devices which can take extended CDBs (>10 bytes).
+ */
+static void
+megaraid_mbox_prepare_epthru(adapter_t *adapter, scb_t *scb,
+		struct scsi_cmnd *scp)
+{
+	mbox_ccb_t		*ccb;
+	mraid_epassthru_t	*epthru;
+	uint8_t			channel;
+	uint8_t			target;
+
+	ccb	= (mbox_ccb_t *)scb->ccb;
+	epthru	= ccb->epthru;
+	channel	= scb->dev_channel;
+	target	= scb->dev_target;
+
+	// 0=6sec, 1=60sec, 2=10min, 3=3hrs, 4=NO timeout
+	epthru->timeout		= 4;	
+	epthru->ars		= 1;
+	epthru->islogical	= 0;
+	epthru->channel		= 0;
+	epthru->target		= (channel << 4) | target;
+	epthru->logdrv		= SCP2LUN(scp);
+	epthru->reqsenselen	= 14;
+	epthru->cdblen		= scp->cmd_len;
+
+	memcpy(epthru->cdb, scp->cmnd, scp->cmd_len);
+
+	if (scsi_bufflen(scp)) {
+		epthru->dataxferlen	= scsi_bufflen(scp);
+		epthru->dataxferaddr	= ccb->sgl_dma_h;
+		epthru->numsge		= megaraid_mbox_mksgl(adapter, scb);
+	}
+	else {
+		epthru->dataxferaddr	= 0;
+		epthru->dataxferlen	= 0;
+		epthru->numsge		= 0;
+	}
+	return;
+}
+
+
+/**
+ * megaraid_ack_sequence - interrupt ack sequence for memory mapped HBAs
+ * @adapter	: controller's soft state
+ *
+ * Interrupt acknowledgement sequence for memory mapped HBAs. Find out the
+ * completed command and put them on the completed list for later processing.
+ *
+ * Returns:	1 if the interrupt is valid, 0 otherwise
+ */
+static int
+megaraid_ack_sequence(adapter_t *adapter)
+{
+	mraid_device_t		*raid_dev = ADAP2RAIDDEV(adapter);
+	mbox_t			*mbox;
+	scb_t			*scb;
+	uint8_t			nstatus;
+	uint8_t			completed[MBOX_MAX_FIRMWARE_STATUS];
+	struct list_head	clist;
+	int			handled;
+	uint32_t		dword;
+	unsigned long		flags;
+	int			i, j;
+
+
+	mbox	= raid_dev->mbox;
+
+	// move the SCBs from the firmware completed array to our local list
+	INIT_LIST_HEAD(&clist);
+
+	// loop till F/W has more commands for us to complete
+	handled = 0;
+	spin_lock_irqsave(MAILBOX_LOCK(raid_dev), flags);
+	do {
+		/*
+		 * Check if a valid interrupt is pending. If found, force the
+		 * interrupt line low.
+		 */
+		dword = RDOUTDOOR(raid_dev);
+		if (dword != 0x10001234) break;
+
+		handled = 1;
+
+		WROUTDOOR(raid_dev, 0x10001234);
+
+		nstatus = 0;
+		// wait for valid numstatus to post
+		for (i = 0; i < 0xFFFFF; i++) {
+			if (mbox->numstatus != 0xFF) {
+				nstatus = mbox->numstatus;
+				break;
+			}
+			rmb();
+		}
+		mbox->numstatus = 0xFF;
+
+		adapter->outstanding_cmds -= nstatus;
+
+		for (i = 0; i < nstatus; i++) {
+
+			// wait for valid command index to post
+			for (j = 0; j < 0xFFFFF; j++) {
+				if (mbox->completed[i] != 0xFF) break;
+				rmb();
+			}
+			completed[i]		= mbox->completed[i];
+			mbox->completed[i]	= 0xFF;
+
+			if (completed[i] == 0xFF) {
+				con_log(CL_ANN, (KERN_CRIT
+				"megaraid: command posting timed out\n"));
+
+				BUG();
+				continue;
+			}
+
+			// Get SCB associated with this command id
+			if (completed[i] >= MBOX_MAX_SCSI_CMDS) {
+				// a cmm command
+				scb = adapter->uscb_list + (completed[i] -
+						MBOX_MAX_SCSI_CMDS);
+			}
+			else {
+				// an os command
+				scb = adapter->kscb_list + completed[i];
+			}
+
+			scb->status = mbox->status;
+			list_add_tail(&scb->list, &clist);
+		}
+
+		// Acknowledge interrupt
+		WRINDOOR(raid_dev, 0x02);
+
+	} while(1);
+
+	spin_unlock_irqrestore(MAILBOX_LOCK(raid_dev), flags);
+
+
+	// put the completed commands in the completed list. DPC would
+	// complete these commands later
+	spin_lock_irqsave(COMPLETED_LIST_LOCK(adapter), flags);
+
+	list_splice(&clist, &adapter->completed_list);
+
+	spin_unlock_irqrestore(COMPLETED_LIST_LOCK(adapter), flags);
+
+
+	// schedule the DPC if there is some work for it
+	if (handled)
+		tasklet_schedule(&adapter->dpc_h);
+
+	return handled;
+}
+
+
+/**
+ * megaraid_isr - isr for memory based mailbox based controllers
+ * @irq		: irq
+ * @devp	: pointer to our soft state
+ *
+ * Interrupt service routine for memory-mapped mailbox controllers.
+ */
+static irqreturn_t
+megaraid_isr(int irq, void *devp)
+{
+	adapter_t	*adapter = devp;
+	int		handled;
+
+	handled = megaraid_ack_sequence(adapter);
+
+	/* Loop through any pending requests */
+	if (!adapter->quiescent) {
+		megaraid_mbox_runpendq(adapter, NULL);
+	}
+
+	return IRQ_RETVAL(handled);
+}
+
+
+/**
+ * megaraid_mbox_dpc - the tasklet to complete the commands from completed list
+ * @devp	: pointer to HBA soft state
+ *
+ * Pick up the commands from the completed list and send back to the owners.
+ * This is a reentrant function and does not assume any locks are held while
+ * it is being called.
+ */
+static void
+megaraid_mbox_dpc(unsigned long devp)
+{
+	adapter_t		*adapter = (adapter_t *)devp;
+	mraid_device_t		*raid_dev;
+	struct list_head	clist;
+	struct scatterlist	*sgl;
+	scb_t			*scb;
+	scb_t			*tmp;
+	struct scsi_cmnd	*scp;
+	mraid_passthru_t	*pthru;
+	mraid_epassthru_t	*epthru;
+	mbox_ccb_t		*ccb;
+	int			islogical;
+	int			pdev_index;
+	int			pdev_state;
+	mbox_t			*mbox;
+	unsigned long		flags;
+	uint8_t			c;
+	int			status;
+	uioc_t			*kioc;
+
+
+	if (!adapter) return;
+
+	raid_dev = ADAP2RAIDDEV(adapter);
+
+	// move the SCBs from the completed list to our local list
+	INIT_LIST_HEAD(&clist);
+
+	spin_lock_irqsave(COMPLETED_LIST_LOCK(adapter), flags);
+
+	list_splice_init(&adapter->completed_list, &clist);
+
+	spin_unlock_irqrestore(COMPLETED_LIST_LOCK(adapter), flags);
+
+
+	list_for_each_entry_safe(scb, tmp, &clist, list) {
+
+		status		= scb->status;
+		scp		= scb->scp;
+		ccb		= (mbox_ccb_t *)scb->ccb;
+		pthru		= ccb->pthru;
+		epthru		= ccb->epthru;
+		mbox		= ccb->mbox;
+
+		// Make sure f/w has completed a valid command
+		if (scb->state != SCB_ISSUED) {
+			con_log(CL_ANN, (KERN_CRIT
+			"megaraid critical err: invalid command %d:%d:%p\n",
+				scb->sno, scb->state, scp));
+			BUG();
+			continue;	// Must never happen!
+		}
+
+		// check for the management command and complete it right away
+		if (scb->sno >= MBOX_MAX_SCSI_CMDS) {
+			scb->state	= SCB_FREE;
+			scb->status	= status;
+
+			// remove from local clist
+			list_del_init(&scb->list);
+
+			kioc			= (uioc_t *)scb->gp;
+			kioc->status		= 0;
+
+			megaraid_mbox_mm_done(adapter, scb);
+
+			continue;
+		}
+
+		// Was an abort issued for this command earlier
+		if (scb->state & SCB_ABORT) {
+			con_log(CL_ANN, (KERN_NOTICE
+			"megaraid: aborted cmd [%x] completed\n",
+				scb->sno));
+		}
+
+		/*
+		 * If the inquiry came of a disk drive which is not part of
+		 * any RAID array, expose it to the kernel. For this to be
+		 * enabled, user must set the "megaraid_expose_unconf_disks"
+		 * flag to 1 by specifying it on module parameter list.
+		 * This would enable data migration off drives from other
+		 * configurations.
+		 */
+		islogical = MRAID_IS_LOGICAL(adapter, scp);
+		if (scp->cmnd[0] == INQUIRY && status == 0 && islogical == 0
+				&& IS_RAID_CH(raid_dev, scb->dev_channel)) {
+
+			sgl = scsi_sglist(scp);
+			if (sg_page(sgl)) {
+				c = *(unsigned char *) sg_virt(&sgl[0]);
+			} else {
+				con_log(CL_ANN, (KERN_WARNING
+						 "megaraid mailbox: invalid sg:%d\n",
+						 __LINE__));
+				c = 0;
+			}
+
+			if ((c & 0x1F ) == TYPE_DISK) {
+				pdev_index = (scb->dev_channel * 16) +
+					scb->dev_target;
+				pdev_state =
+					raid_dev->pdrv_state[pdev_index] & 0x0F;
+
+				if (pdev_state == PDRV_ONLINE		||
+					pdev_state == PDRV_FAILED	||
+					pdev_state == PDRV_RBLD		||
+					pdev_state == PDRV_HOTSPARE	||
+					megaraid_expose_unconf_disks == 0) {
+
+					status = 0xF0;
+				}
+			}
+		}
+
+		// Convert MegaRAID status to Linux error code
+		switch (status) {
+
+		case 0x00:
+
+			scp->result = (DID_OK << 16);
+			break;
+
+		case 0x02:
+
+			/* set sense_buffer and result fields */
+			if (mbox->cmd == MBOXCMD_PASSTHRU ||
+				mbox->cmd == MBOXCMD_PASSTHRU64) {
+
+				memcpy(scp->sense_buffer, pthru->reqsensearea,
+						14);
+
+				scp->result = SAM_STAT_CHECK_CONDITION;
+			}
+			else {
+				if (mbox->cmd == MBOXCMD_EXTPTHRU) {
+
+					memcpy(scp->sense_buffer,
+						epthru->reqsensearea, 14);
+
+					scp->result = SAM_STAT_CHECK_CONDITION;
+				} else
+					scsi_build_sense(scp, 0,
+							 ABORTED_COMMAND, 0, 0);
+			}
+			break;
+
+		case 0x08:
+
+			scp->result = DID_BUS_BUSY << 16 | status;
+			break;
+
+		default:
+
+			/*
+			 * If TEST_UNIT_READY fails, we know RESERVATION_STATUS
+			 * failed
+			 */
+			if (scp->cmnd[0] == TEST_UNIT_READY) {
+				scp->result = DID_ERROR << 16 |
+					SAM_STAT_RESERVATION_CONFLICT;
+			}
+			else
+			/*
+			 * Error code returned is 1 if Reserve or Release
+			 * failed or the input parameter is invalid
+			 */
+			if (status == 1 && (scp->cmnd[0] == RESERVE ||
+					 scp->cmnd[0] == RELEASE)) {
+
+				scp->result = DID_ERROR << 16 |
+					SAM_STAT_RESERVATION_CONFLICT;
+			}
+			else {
+				scp->result = DID_BAD_TARGET << 16 | status;
+			}
+		}
+
+		// print a debug message for all failed commands
+		if (status) {
+			megaraid_mbox_display_scb(adapter, scb);
+		}
+
+		scsi_dma_unmap(scp);
+
+		// remove from local clist
+		list_del_init(&scb->list);
+
+		// put back in free list
+		megaraid_dealloc_scb(adapter, scb);
+
+		// send the scsi packet back to kernel
+		scsi_done(scp);
+	}
+
+	return;
+}
+
+
+/**
+ * megaraid_abort_handler - abort the scsi command
+ * @scp		: command to be aborted
+ *
+ * Abort a previous SCSI request. Only commands on the pending list can be
+ * aborted. All the commands issued to the F/W must complete.
+ **/
+static int
+megaraid_abort_handler(struct scsi_cmnd *scp)
+{
+	adapter_t		*adapter;
+	mraid_device_t		*raid_dev;
+	scb_t			*scb;
+	scb_t			*tmp;
+	int			found;
+	unsigned long		flags;
+	int			i;
+
+
+	adapter		= SCP2ADAPTER(scp);
+	raid_dev	= ADAP2RAIDDEV(adapter);
+
+	con_log(CL_ANN, (KERN_WARNING
+		"megaraid: aborting cmd=%x <c=%d t=%d l=%d>\n",
+		scp->cmnd[0], SCP2CHANNEL(scp),
+		SCP2TARGET(scp), SCP2LUN(scp)));
+
+	// If FW has stopped responding, simply return failure
+	if (raid_dev->hw_error) {
+		con_log(CL_ANN, (KERN_NOTICE
+			"megaraid: hw error, not aborting\n"));
+		return FAILED;
+	}
+
+	// There might a race here, where the command was completed by the
+	// firmware and now it is on the completed list. Before we could
+	// complete the command to the kernel in dpc, the abort came.
+	// Find out if this is the case to avoid the race.
+	scb = NULL;
+	spin_lock_irqsave(COMPLETED_LIST_LOCK(adapter), flags);
+	list_for_each_entry_safe(scb, tmp, &adapter->completed_list, list) {
+
+		if (scb->scp == scp) {	// Found command
+
+			list_del_init(&scb->list);	// from completed list
+
+			con_log(CL_ANN, (KERN_WARNING
+			"megaraid: %d[%d:%d], abort from completed list\n",
+				scb->sno, scb->dev_channel, scb->dev_target));
+
+			scp->result = (DID_ABORT << 16);
+			scsi_done(scp);
+
+			megaraid_dealloc_scb(adapter, scb);
+
+			spin_unlock_irqrestore(COMPLETED_LIST_LOCK(adapter),
+				flags);
+
+			return SUCCESS;
+		}
+	}
+	spin_unlock_irqrestore(COMPLETED_LIST_LOCK(adapter), flags);
+
+
+	// Find out if this command is still on the pending list. If it is and
+	// was never issued, abort and return success. If the command is owned
+	// by the firmware, we must wait for it to complete by the FW.
+	spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);
+	list_for_each_entry_safe(scb, tmp, &adapter->pend_list, list) {
+
+		if (scb->scp == scp) {	// Found command
+
+			list_del_init(&scb->list);	// from pending list
+
+			ASSERT(!(scb->state & SCB_ISSUED));
+
+			con_log(CL_ANN, (KERN_WARNING
+				"megaraid abort: [%d:%d], driver owner\n",
+				scb->dev_channel, scb->dev_target));
+
+			scp->result = (DID_ABORT << 16);
+			scsi_done(scp);
+
+			megaraid_dealloc_scb(adapter, scb);
+
+			spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter),
+				flags);
+
+			return SUCCESS;
+		}
+	}
+	spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);
+
+
+	// Check do we even own this command, in which case this would be
+	// owned by the firmware. The only way to locate the FW scb is to
+	// traverse through the list of all SCB, since driver does not
+	// maintain these SCBs on any list
+	found = 0;
+	spin_lock_irq(&adapter->lock);
+	for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
+		scb = adapter->kscb_list + i;
+
+		if (scb->scp == scp) {
+
+			found = 1;
+
+			if (!(scb->state & SCB_ISSUED)) {
+				con_log(CL_ANN, (KERN_WARNING
+				"megaraid abort: %d[%d:%d], invalid state\n",
+				scb->sno, scb->dev_channel, scb->dev_target));
+				BUG();
+			}
+			else {
+				con_log(CL_ANN, (KERN_WARNING
+				"megaraid abort: %d[%d:%d], fw owner\n",
+				scb->sno, scb->dev_channel, scb->dev_target));
+			}
+		}
+	}
+	spin_unlock_irq(&adapter->lock);
+
+	if (!found) {
+		con_log(CL_ANN, (KERN_WARNING "megaraid abort: do now own\n"));
+
+		// FIXME: Should there be a callback for this command?
+		return SUCCESS;
+	}
+
+	// We cannot actually abort a command owned by firmware, return
+	// failure and wait for reset. In host reset handler, we will find out
+	// if the HBA is still live
+	return FAILED;
+}
+
+/**
+ * megaraid_reset_handler - device reset handler for mailbox based driver
+ * @scp		: reference command
+ *
+ * Reset handler for the mailbox based controller. First try to find out if
+ * the FW is still live, in which case the outstanding commands counter mut go
+ * down to 0. If that happens, also issue the reservation reset command to
+ * relinquish (possible) reservations on the logical drives connected to this
+ * host.
+ **/
+static int
+megaraid_reset_handler(struct scsi_cmnd *scp)
+{
+	adapter_t	*adapter;
+	scb_t		*scb;
+	scb_t		*tmp;
+	mraid_device_t	*raid_dev;
+	unsigned long	flags;
+	uint8_t		raw_mbox[sizeof(mbox_t)];
+	int		rval;
+	int		recovery_window;
+	int		i;
+	uioc_t		*kioc;
+
+	adapter		= SCP2ADAPTER(scp);
+	raid_dev	= ADAP2RAIDDEV(adapter);
+
+	// return failure if adapter is not responding
+	if (raid_dev->hw_error) {
+		con_log(CL_ANN, (KERN_NOTICE
+			"megaraid: hw error, cannot reset\n"));
+		return FAILED;
+	}
+
+	// Under exceptional conditions, FW can take up to 3 minutes to
+	// complete command processing. Wait for additional 2 minutes for the
+	// pending commands counter to go down to 0. If it doesn't, let the
+	// controller be marked offline
+	// Also, reset all the commands currently owned by the driver
+	spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);
+	list_for_each_entry_safe(scb, tmp, &adapter->pend_list, list) {
+		list_del_init(&scb->list);	// from pending list
+
+		if (scb->sno >= MBOX_MAX_SCSI_CMDS) {
+			con_log(CL_ANN, (KERN_WARNING
+			"megaraid: IOCTL packet with %d[%d:%d] being reset\n",
+			scb->sno, scb->dev_channel, scb->dev_target));
+
+			scb->status = -1;
+
+			kioc			= (uioc_t *)scb->gp;
+			kioc->status		= -EFAULT;
+
+			megaraid_mbox_mm_done(adapter, scb);
+		} else {
+			if (scb->scp == scp) {	// Found command
+				con_log(CL_ANN, (KERN_WARNING
+					"megaraid: %d[%d:%d], reset from pending list\n",
+					scb->sno, scb->dev_channel, scb->dev_target));
+			} else {
+				con_log(CL_ANN, (KERN_WARNING
+				"megaraid: IO packet with %d[%d:%d] being reset\n",
+				scb->sno, scb->dev_channel, scb->dev_target));
+			}
+
+			scb->scp->result = (DID_RESET << 16);
+			scsi_done(scb->scp);
+
+			megaraid_dealloc_scb(adapter, scb);
+		}
+	}
+	spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);
+
+	if (adapter->outstanding_cmds) {
+		con_log(CL_ANN, (KERN_NOTICE
+			"megaraid: %d outstanding commands. Max wait %d sec\n",
+			adapter->outstanding_cmds,
+			(MBOX_RESET_WAIT + MBOX_RESET_EXT_WAIT)));
+	}
+
+	recovery_window = MBOX_RESET_WAIT + MBOX_RESET_EXT_WAIT;
+
+	for (i = 0; i < recovery_window; i++) {
+
+		megaraid_ack_sequence(adapter);
+
+		// print a message once every 5 seconds only
+		if (!(i % 5)) {
+			con_log(CL_ANN, (
+			"megaraid mbox: Wait for %d commands to complete:%d\n",
+				adapter->outstanding_cmds,
+				(MBOX_RESET_WAIT + MBOX_RESET_EXT_WAIT) - i));
+		}
+
+		// bailout if no recovery happened in reset time
+		if (adapter->outstanding_cmds == 0) {
+			break;
+		}
+
+		msleep(1000);
+	}
+
+	spin_lock(&adapter->lock);
+
+	// If still outstanding commands, bail out
+	if (adapter->outstanding_cmds) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid mbox: critical hardware error!\n"));
+
+		raid_dev->hw_error = 1;
+
+		rval = FAILED;
+		goto out;
+	}
+	else {
+		con_log(CL_ANN, (KERN_NOTICE
+		"megaraid mbox: reset sequence completed successfully\n"));
+	}
+
+
+	// If the controller supports clustering, reset reservations
+	if (!adapter->ha) {
+		rval = SUCCESS;
+		goto out;
+	}
+
+	// clear reservations if any
+	raw_mbox[0] = CLUSTER_CMD;
+	raw_mbox[2] = RESET_RESERVATIONS;
+
+	rval = SUCCESS;
+	if (mbox_post_sync_cmd_fast(adapter, raw_mbox) == 0) {
+		con_log(CL_ANN,
+			(KERN_INFO "megaraid: reservation reset\n"));
+	}
+	else {
+		rval = FAILED;
+		con_log(CL_ANN, (KERN_WARNING
+				"megaraid: reservation reset failed\n"));
+	}
+
+ out:
+	spin_unlock(&adapter->lock);
+	return rval;
+}
+
+/*
+ * START: internal commands library
+ *
+ * This section of the driver has the common routine used by the driver and
+ * also has all the FW routines
+ */
+
+/**
+ * mbox_post_sync_cmd() - blocking command to the mailbox based controllers
+ * @adapter	: controller's soft state
+ * @raw_mbox	: the mailbox
+ *
+ * Issue a scb in synchronous and non-interrupt mode for mailbox based
+ * controllers.
+ */
+static int
+mbox_post_sync_cmd(adapter_t *adapter, uint8_t raw_mbox[])
+{
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+	mbox_t		*mbox;
+	uint8_t		status;
+	int		i;
+
+	mbox	= raid_dev->mbox;
+
+	/*
+	 * Wait until mailbox is free
+	 */
+	if (megaraid_busywait_mbox(raid_dev) != 0)
+		goto blocked_mailbox;
+
+	/*
+	 * Copy mailbox data into host structure
+	 */
+	memcpy((caddr_t)mbox, (caddr_t)raw_mbox, 16);
+	mbox->cmdid		= 0xFE;
+	mbox->busy		= 1;
+	mbox->poll		= 0;
+	mbox->ack		= 0;
+	mbox->numstatus		= 0xFF;
+	mbox->status		= 0xFF;
+
+	wmb();
+	WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);
+
+	// wait for maximum 1 second for status to post. If the status is not
+	// available within 1 second, assume FW is initializing and wait
+	// for an extended amount of time
+	if (mbox->numstatus == 0xFF) {	// status not yet available
+		udelay(25);
+
+		for (i = 0; mbox->numstatus == 0xFF && i < 1000; i++) {
+			rmb();
+			msleep(1);
+		}
+
+
+		if (i == 1000) {
+			con_log(CL_ANN, (KERN_NOTICE
+				"megaraid mailbox: wait for FW to boot      "));
+
+			for (i = 0; (mbox->numstatus == 0xFF) &&
+					(i < MBOX_RESET_WAIT); i++) {
+				rmb();
+				con_log(CL_ANN, ("\b\b\b\b\b[%03d]",
+							MBOX_RESET_WAIT - i));
+				msleep(1000);
+			}
+
+			if (i == MBOX_RESET_WAIT) {
+
+				con_log(CL_ANN, (
+				"\nmegaraid mailbox: status not available\n"));
+
+				return -1;
+			}
+			con_log(CL_ANN, ("\b\b\b\b\b[ok] \n"));
+		}
+	}
+
+	// wait for maximum 1 second for poll semaphore
+	if (mbox->poll != 0x77) {
+		udelay(25);
+
+		for (i = 0; (mbox->poll != 0x77) && (i < 1000); i++) {
+			rmb();
+			msleep(1);
+		}
+
+		if (i == 1000) {
+			con_log(CL_ANN, (KERN_WARNING
+			"megaraid mailbox: could not get poll semaphore\n"));
+			return -1;
+		}
+	}
+
+	WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x2);
+	wmb();
+
+	// wait for maximum 1 second for acknowledgement
+	if (RDINDOOR(raid_dev) & 0x2) {
+		udelay(25);
+
+		for (i = 0; (RDINDOOR(raid_dev) & 0x2) && (i < 1000); i++) {
+			rmb();
+			msleep(1);
+		}
+
+		if (i == 1000) {
+			con_log(CL_ANN, (KERN_WARNING
+				"megaraid mailbox: could not acknowledge\n"));
+			return -1;
+		}
+	}
+	mbox->poll	= 0;
+	mbox->ack	= 0x77;
+
+	status = mbox->status;
+
+	// invalidate the completed command id array. After command
+	// completion, firmware would write the valid id.
+	mbox->numstatus	= 0xFF;
+	mbox->status	= 0xFF;
+	for (i = 0; i < MBOX_MAX_FIRMWARE_STATUS; i++) {
+		mbox->completed[i] = 0xFF;
+	}
+
+	return status;
+
+blocked_mailbox:
+
+	con_log(CL_ANN, (KERN_WARNING "megaraid: blocked mailbox\n") );
+	return -1;
+}
+
+
+/**
+ * mbox_post_sync_cmd_fast - blocking command to the mailbox based controllers
+ * @adapter	: controller's soft state
+ * @raw_mbox	: the mailbox
+ *
+ * Issue a scb in synchronous and non-interrupt mode for mailbox based
+ * controllers. This is a faster version of the synchronous command and
+ * therefore can be called in interrupt-context as well.
+ */
+static int
+mbox_post_sync_cmd_fast(adapter_t *adapter, uint8_t raw_mbox[])
+{
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+	mbox_t		*mbox;
+	long		i;
+
+
+	mbox	= raid_dev->mbox;
+
+	// return immediately if the mailbox is busy
+	if (mbox->busy) return -1;
+
+	// Copy mailbox data into host structure
+	memcpy((caddr_t)mbox, (caddr_t)raw_mbox, 14);
+	mbox->cmdid		= 0xFE;
+	mbox->busy		= 1;
+	mbox->poll		= 0;
+	mbox->ack		= 0;
+	mbox->numstatus		= 0xFF;
+	mbox->status		= 0xFF;
+
+	wmb();
+	WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);
+
+	for (i = 0; i < MBOX_SYNC_WAIT_CNT; i++) {
+		if (mbox->numstatus != 0xFF) break;
+		rmb();
+		udelay(MBOX_SYNC_DELAY_200);
+	}
+
+	if (i == MBOX_SYNC_WAIT_CNT) {
+		// We may need to re-calibrate the counter
+		con_log(CL_ANN, (KERN_CRIT
+			"megaraid: fast sync command timed out\n"));
+	}
+
+	WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x2);
+	wmb();
+
+	return mbox->status;
+}
+
+
+/**
+ * megaraid_busywait_mbox() - Wait until the controller's mailbox is available
+ * @raid_dev	: RAID device (HBA) soft state
+ *
+ * Wait until the controller's mailbox is available to accept more commands.
+ * Wait for at most 1 second.
+ */
+static int
+megaraid_busywait_mbox(mraid_device_t *raid_dev)
+{
+	mbox_t	*mbox = raid_dev->mbox;
+	int	i = 0;
+
+	if (mbox->busy) {
+		udelay(25);
+		for (i = 0; mbox->busy && i < 1000; i++)
+			msleep(1);
+	}
+
+	if (i < 1000) return 0;
+	else return -1;
+}
+
+
+/**
+ * megaraid_mbox_product_info - some static information about the controller
+ * @adapter	: our soft state
+ *
+ * Issue commands to the controller to grab some parameters required by our
+ * caller.
+ */
+static int
+megaraid_mbox_product_info(adapter_t *adapter)
+{
+	mraid_device_t		*raid_dev = ADAP2RAIDDEV(adapter);
+	mbox_t			*mbox;
+	uint8_t			raw_mbox[sizeof(mbox_t)];
+	mraid_pinfo_t		*pinfo;
+	dma_addr_t		pinfo_dma_h;
+	mraid_inquiry3_t	*mraid_inq3;
+	int			i;
+
+
+	memset((caddr_t)raw_mbox, 0, sizeof(raw_mbox));
+	mbox = (mbox_t *)raw_mbox;
+
+	/*
+	 * Issue an ENQUIRY3 command to find out certain adapter parameters,
+	 * e.g., max channels, max commands etc.
+	 */
+	pinfo = dma_alloc_coherent(&adapter->pdev->dev, sizeof(mraid_pinfo_t),
+				   &pinfo_dma_h, GFP_KERNEL);
+	if (pinfo == NULL) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: out of memory, %s %d\n", __func__,
+			__LINE__));
+
+		return -1;
+	}
+
+	mbox->xferaddr = (uint32_t)adapter->ibuf_dma_h;
+	memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);
+
+	raw_mbox[0] = FC_NEW_CONFIG;
+	raw_mbox[2] = NC_SUBOP_ENQUIRY3;
+	raw_mbox[3] = ENQ3_GET_SOLICITED_FULL;
+
+	// Issue the command
+	if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {
+
+		con_log(CL_ANN, (KERN_WARNING "megaraid: Inquiry3 failed\n"));
+
+		dma_free_coherent(&adapter->pdev->dev, sizeof(mraid_pinfo_t),
+			pinfo, pinfo_dma_h);
+
+		return -1;
+	}
+
+	/*
+	 * Collect information about state of each physical drive
+	 * attached to the controller. We will expose all the disks
+	 * which are not part of RAID
+	 */
+	mraid_inq3 = (mraid_inquiry3_t *)adapter->ibuf;
+	for (i = 0; i < MBOX_MAX_PHYSICAL_DRIVES; i++) {
+		raid_dev->pdrv_state[i] = mraid_inq3->pdrv_state[i];
+	}
+
+	/*
+	 * Get product info for information like number of channels,
+	 * maximum commands supported.
+	 */
+	memset((caddr_t)raw_mbox, 0, sizeof(raw_mbox));
+	mbox->xferaddr = (uint32_t)pinfo_dma_h;
+
+	raw_mbox[0] = FC_NEW_CONFIG;
+	raw_mbox[2] = NC_SUBOP_PRODUCT_INFO;
+
+	if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: product info failed\n"));
+
+		dma_free_coherent(&adapter->pdev->dev, sizeof(mraid_pinfo_t),
+			pinfo, pinfo_dma_h);
+
+		return -1;
+	}
+
+	/*
+	 * Setup some parameters for host, as required by our caller
+	 */
+	adapter->max_channel = pinfo->nchannels;
+
+	/*
+	 * we will export all the logical drives on a single channel.
+	 * Add 1 since inquires do not come for inititor ID
+	 */
+	adapter->max_target	= MAX_LOGICAL_DRIVES_40LD + 1;
+	adapter->max_lun	= 8;	// up to 8 LUNs for non-disk devices
+
+	/*
+	 * These are the maximum outstanding commands for the scsi-layer
+	 */
+	adapter->max_cmds	= MBOX_MAX_SCSI_CMDS;
+
+	memset(adapter->fw_version, 0, VERSION_SIZE);
+	memset(adapter->bios_version, 0, VERSION_SIZE);
+
+	memcpy(adapter->fw_version, pinfo->fw_version, 4);
+	adapter->fw_version[4] = 0;
+
+	memcpy(adapter->bios_version, pinfo->bios_version, 4);
+	adapter->bios_version[4] = 0;
+
+	con_log(CL_ANN, (KERN_NOTICE
+		"megaraid: fw version:[%s] bios version:[%s]\n",
+		adapter->fw_version, adapter->bios_version));
+
+	dma_free_coherent(&adapter->pdev->dev, sizeof(mraid_pinfo_t), pinfo,
+			pinfo_dma_h);
+
+	return 0;
+}
+
+
+
+/**
+ * megaraid_mbox_extended_cdb - check for support for extended CDBs
+ * @adapter	: soft state for the controller
+ *
+ * This routine check whether the controller in question supports extended
+ * ( > 10 bytes ) CDBs.
+ */
+static int
+megaraid_mbox_extended_cdb(adapter_t *adapter)
+{
+	mbox_t		*mbox;
+	uint8_t		raw_mbox[sizeof(mbox_t)];
+	int		rval;
+
+	mbox = (mbox_t *)raw_mbox;
+
+	memset((caddr_t)raw_mbox, 0, sizeof(raw_mbox));
+	mbox->xferaddr	= (uint32_t)adapter->ibuf_dma_h;
+
+	memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);
+
+	raw_mbox[0] = MAIN_MISC_OPCODE;
+	raw_mbox[2] = SUPPORT_EXT_CDB;
+
+	/*
+	 * Issue the command
+	 */
+	rval = 0;
+	if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {
+		rval = -1;
+	}
+
+	return rval;
+}
+
+
+/**
+ * megaraid_mbox_support_ha - Do we support clustering
+ * @adapter	: soft state for the controller
+ * @init_id	: ID of the initiator
+ *
+ * Determine if the firmware supports clustering and the ID of the initiator.
+ */
+static int
+megaraid_mbox_support_ha(adapter_t *adapter, uint16_t *init_id)
+{
+	mbox_t		*mbox;
+	uint8_t		raw_mbox[sizeof(mbox_t)];
+	int		rval;
+
+
+	mbox = (mbox_t *)raw_mbox;
+
+	memset((caddr_t)raw_mbox, 0, sizeof(raw_mbox));
+
+	mbox->xferaddr = (uint32_t)adapter->ibuf_dma_h;
+
+	memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);
+
+	raw_mbox[0] = GET_TARGET_ID;
+
+	// Issue the command
+	*init_id = 7;
+	rval =  -1;
+	if (mbox_post_sync_cmd(adapter, raw_mbox) == 0) {
+
+		*init_id = *(uint8_t *)adapter->ibuf;
+
+		con_log(CL_ANN, (KERN_INFO
+			"megaraid: cluster firmware, initiator ID: %d\n",
+			*init_id));
+
+		rval =  0;
+	}
+
+	return rval;
+}
+
+
+/**
+ * megaraid_mbox_support_random_del - Do we support random deletion
+ * @adapter	: soft state for the controller
+ *
+ * Determine if the firmware supports random deletion.
+ * Return:	1 is operation supported, 0 otherwise
+ */
+static int
+megaraid_mbox_support_random_del(adapter_t *adapter)
+{
+	uint8_t		raw_mbox[sizeof(mbox_t)];
+	int		rval;
+
+	/*
+	 * Newer firmware on Dell CERC expect a different
+	 * random deletion handling, so disable it.
+	 */
+	if (adapter->pdev->vendor == PCI_VENDOR_ID_AMI &&
+	    adapter->pdev->device == PCI_DEVICE_ID_AMI_MEGARAID3 &&
+	    adapter->pdev->subsystem_vendor == PCI_VENDOR_ID_DELL &&
+	    adapter->pdev->subsystem_device == PCI_SUBSYS_ID_CERC_ATA100_4CH &&
+	    (adapter->fw_version[0] > '6' ||
+	     (adapter->fw_version[0] == '6' &&
+	      adapter->fw_version[2] > '6') ||
+	     (adapter->fw_version[0] == '6'
+	      && adapter->fw_version[2] == '6'
+	      && adapter->fw_version[3] > '1'))) {
+		con_log(CL_DLEVEL1, ("megaraid: disable random deletion\n"));
+		return 0;
+	}
+
+	memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));
+
+	raw_mbox[0] = FC_DEL_LOGDRV;
+	raw_mbox[2] = OP_SUP_DEL_LOGDRV;
+
+	// Issue the command
+	rval = 0;
+	if (mbox_post_sync_cmd(adapter, raw_mbox) == 0) {
+
+		con_log(CL_DLEVEL1, ("megaraid: supports random deletion\n"));
+
+		rval =  1;
+	}
+
+	return rval;
+}
+
+
+/**
+ * megaraid_mbox_get_max_sg - maximum sg elements supported by the firmware
+ * @adapter	: soft state for the controller
+ *
+ * Find out the maximum number of scatter-gather elements supported by the
+ * firmware.
+ */
+static int
+megaraid_mbox_get_max_sg(adapter_t *adapter)
+{
+	mbox_t		*mbox;
+	uint8_t		raw_mbox[sizeof(mbox_t)];
+	int		nsg;
+
+
+	mbox = (mbox_t *)raw_mbox;
+
+	memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));
+
+	mbox->xferaddr = (uint32_t)adapter->ibuf_dma_h;
+
+	memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);
+
+	raw_mbox[0] = MAIN_MISC_OPCODE;
+	raw_mbox[2] = GET_MAX_SG_SUPPORT;
+
+	// Issue the command
+	if (mbox_post_sync_cmd(adapter, raw_mbox) == 0) {
+		nsg =  *(uint8_t *)adapter->ibuf;
+	}
+	else {
+		nsg =  MBOX_DEFAULT_SG_SIZE;
+	}
+
+	if (nsg > MBOX_MAX_SG_SIZE) nsg = MBOX_MAX_SG_SIZE;
+
+	return nsg;
+}
+
+
+/**
+ * megaraid_mbox_enum_raid_scsi - enumerate the RAID and SCSI channels
+ * @adapter	: soft state for the controller
+ *
+ * Enumerate the RAID and SCSI channels for ROMB platforms so that channels
+ * can be exported as regular SCSI channels.
+ */
+static void
+megaraid_mbox_enum_raid_scsi(adapter_t *adapter)
+{
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+	mbox_t		*mbox;
+	uint8_t		raw_mbox[sizeof(mbox_t)];
+
+
+	mbox = (mbox_t *)raw_mbox;
+
+	memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));
+
+	mbox->xferaddr = (uint32_t)adapter->ibuf_dma_h;
+
+	memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);
+
+	raw_mbox[0] = CHNL_CLASS;
+	raw_mbox[2] = GET_CHNL_CLASS;
+
+	// Issue the command. If the command fails, all channels are RAID
+	// channels
+	raid_dev->channel_class = 0xFF;
+	if (mbox_post_sync_cmd(adapter, raw_mbox) == 0) {
+		raid_dev->channel_class =  *(uint8_t *)adapter->ibuf;
+	}
+
+	return;
+}
+
+
+/**
+ * megaraid_mbox_flush_cache - flush adapter and disks cache
+ * @adapter		: soft state for the controller
+ *
+ * Flush adapter cache followed by disks cache.
+ */
+static void
+megaraid_mbox_flush_cache(adapter_t *adapter)
+{
+	uint8_t	raw_mbox[sizeof(mbox_t)];
+
+	memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));
+
+	raw_mbox[0] = FLUSH_ADAPTER;
+
+	if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {
+		con_log(CL_ANN, ("megaraid: flush adapter failed\n"));
+	}
+
+	raw_mbox[0] = FLUSH_SYSTEM;
+
+	if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {
+		con_log(CL_ANN, ("megaraid: flush disks cache failed\n"));
+	}
+
+	return;
+}
+
+
+/**
+ * megaraid_mbox_fire_sync_cmd - fire the sync cmd
+ * @adapter		: soft state for the controller
+ *
+ * Clears the pending cmds in FW and reinits its RAID structs.
+ */
+static int
+megaraid_mbox_fire_sync_cmd(adapter_t *adapter)
+{
+	mbox_t	*mbox;
+	uint8_t	raw_mbox[sizeof(mbox_t)];
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+	int	status = 0;
+	int i;
+	uint32_t dword;
+
+	memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));
+
+	raw_mbox[0] = 0xFF;
+
+	mbox	= raid_dev->mbox;
+
+	/* Wait until mailbox is free */
+	if (megaraid_busywait_mbox(raid_dev) != 0) {
+		status = 1;
+		goto blocked_mailbox;
+	}
+
+	/* Copy mailbox data into host structure */
+	memcpy((caddr_t)mbox, (caddr_t)raw_mbox, 16);
+	mbox->cmdid		= 0xFE;
+	mbox->busy		= 1;
+	mbox->poll		= 0;
+	mbox->ack		= 0;
+	mbox->numstatus		= 0;
+	mbox->status		= 0;
+
+	wmb();
+	WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);
+
+	/* Wait for maximum 1 min for status to post.
+	 * If the Firmware SUPPORTS the ABOVE COMMAND,
+	 * mbox->cmd will be set to 0
+	 * else
+	 * the firmware will reject the command with
+	 * mbox->numstatus set to 1
+	 */
+
+	i = 0;
+	status = 0;
+	while (!mbox->numstatus && mbox->cmd == 0xFF) {
+		rmb();
+		msleep(1);
+		i++;
+		if (i > 1000 * 60) {
+			status = 1;
+			break;
+		}
+	}
+	if (mbox->numstatus == 1)
+		status = 1; /*cmd not supported*/
+
+	/* Check for interrupt line */
+	dword = RDOUTDOOR(raid_dev);
+	WROUTDOOR(raid_dev, dword);
+	WRINDOOR(raid_dev,2);
+
+	return status;
+
+blocked_mailbox:
+	con_log(CL_ANN, (KERN_WARNING "megaraid: blocked mailbox\n"));
+	return status;
+}
+
+/**
+ * megaraid_mbox_display_scb - display SCB information, mostly debug purposes
+ * @adapter		: controller's soft state
+ * @scb			: SCB to be displayed
+ *
+ * Diplay information about the given SCB iff the current debug level is
+ * verbose.
+ */
+static void
+megaraid_mbox_display_scb(adapter_t *adapter, scb_t *scb)
+{
+	mbox_ccb_t		*ccb;
+	struct scsi_cmnd	*scp;
+	mbox_t			*mbox;
+	int			level;
+	int			i;
+
+
+	ccb	= (mbox_ccb_t *)scb->ccb;
+	scp	= scb->scp;
+	mbox	= ccb->mbox;
+
+	level = CL_DLEVEL3;
+
+	con_log(level, (KERN_NOTICE
+		"megaraid mailbox: status:%#x cmd:%#x id:%#x ", scb->status,
+		mbox->cmd, scb->sno));
+
+	con_log(level, ("sec:%#x lba:%#x addr:%#x ld:%d sg:%d\n",
+		mbox->numsectors, mbox->lba, mbox->xferaddr, mbox->logdrv,
+		mbox->numsge));
+
+	if (!scp) return;
+
+	con_log(level, (KERN_NOTICE "scsi cmnd: "));
+
+	for (i = 0; i < scp->cmd_len; i++) {
+		con_log(level, ("%#2.02x ", scp->cmnd[i]));
+	}
+
+	con_log(level, ("\n"));
+
+	return;
+}
+
+
+/**
+ * megaraid_mbox_setup_device_map - manage device ids
+ * @adapter	: Driver's soft state
+ *
+ * Manage the device ids to have an appropriate mapping between the kernel
+ * scsi addresses and megaraid scsi and logical drive addresses. We export
+ * scsi devices on their actual addresses, whereas the logical drives are
+ * exported on a virtual scsi channel.
+ */
+static void
+megaraid_mbox_setup_device_map(adapter_t *adapter)
+{
+	uint8_t		c;
+	uint8_t		t;
+
+	/*
+	 * First fill the values on the logical drive channel
+	 */
+	for (t = 0; t < LSI_MAX_LOGICAL_DRIVES_64LD; t++)
+		adapter->device_ids[adapter->max_channel][t] =
+			(t < adapter->init_id) ?  t : t - 1;
+
+	adapter->device_ids[adapter->max_channel][adapter->init_id] = 0xFF;
+
+	/*
+	 * Fill the values on the physical devices channels
+	 */
+	for (c = 0; c < adapter->max_channel; c++)
+		for (t = 0; t < LSI_MAX_LOGICAL_DRIVES_64LD; t++)
+			adapter->device_ids[c][t] = (c << 8) | t;
+}
+
+
+/*
+ * END: internal commands library
+ */
+
+/*
+ * START: Interface for the common management module
+ *
+ * This is the module, which interfaces with the common management module to
+ * provide support for ioctl and sysfs
+ */
+
+/**
+ * megaraid_cmm_register - register with the management module
+ * @adapter		: HBA soft state
+ *
+ * Register with the management module, which allows applications to issue
+ * ioctl calls to the drivers. This interface is used by the management module
+ * to setup sysfs support as well.
+ */
+static int
+megaraid_cmm_register(adapter_t *adapter)
+{
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+	mraid_mmadp_t	adp;
+	scb_t		*scb;
+	mbox_ccb_t	*ccb;
+	int		rval;
+	int		i;
+
+	// Allocate memory for the base list of scb for management module.
+	adapter->uscb_list = kcalloc(MBOX_MAX_USER_CMDS, sizeof(scb_t), GFP_KERNEL);
+
+	if (adapter->uscb_list == NULL) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: out of memory, %s %d\n", __func__,
+			__LINE__));
+		return -1;
+	}
+
+
+	// Initialize the synchronization parameters for resources for
+	// commands for management module
+	INIT_LIST_HEAD(&adapter->uscb_pool);
+
+	spin_lock_init(USER_FREE_LIST_LOCK(adapter));
+
+
+
+	// link all the packets. Note, CCB for commands, coming from the
+	// commom management module, mailbox physical address are already
+	// setup by it. We just need placeholder for that in our local command
+	// control blocks
+	for (i = 0; i < MBOX_MAX_USER_CMDS; i++) {
+
+		scb			= adapter->uscb_list + i;
+		ccb			= raid_dev->uccb_list + i;
+
+		scb->ccb		= (caddr_t)ccb;
+		ccb->mbox64		= raid_dev->umbox64 + i;
+		ccb->mbox		= &ccb->mbox64->mbox32;
+		ccb->raw_mbox		= (uint8_t *)ccb->mbox;
+
+		scb->gp			= 0;
+
+		// COMMAND ID 0 - (MBOX_MAX_SCSI_CMDS-1) ARE RESERVED FOR
+		// COMMANDS COMING FROM IO SUBSYSTEM (MID-LAYER)
+		scb->sno		= i + MBOX_MAX_SCSI_CMDS;
+
+		scb->scp		= NULL;
+		scb->state		= SCB_FREE;
+		scb->dma_direction	= DMA_NONE;
+		scb->dma_type		= MRAID_DMA_NONE;
+		scb->dev_channel	= -1;
+		scb->dev_target		= -1;
+
+		// put scb in the free pool
+		list_add_tail(&scb->list, &adapter->uscb_pool);
+	}
+
+	adp.unique_id		= adapter->unique_id;
+	adp.drvr_type		= DRVRTYPE_MBOX;
+	adp.drvr_data		= (unsigned long)adapter;
+	adp.pdev		= adapter->pdev;
+	adp.issue_uioc		= megaraid_mbox_mm_handler;
+	adp.timeout		= MBOX_RESET_WAIT + MBOX_RESET_EXT_WAIT;
+	adp.max_kioc		= MBOX_MAX_USER_CMDS;
+
+	if ((rval = mraid_mm_register_adp(&adp)) != 0) {
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid mbox: did not register with CMM\n"));
+
+		kfree(adapter->uscb_list);
+	}
+
+	return rval;
+}
+
+
+/**
+ * megaraid_cmm_unregister - un-register with the management module
+ * @adapter		: HBA soft state
+ *
+ * Un-register with the management module.
+ * FIXME: mgmt module must return failure for unregister if it has pending
+ * commands in LLD.
+ */
+static int
+megaraid_cmm_unregister(adapter_t *adapter)
+{
+	kfree(adapter->uscb_list);
+	mraid_mm_unregister_adp(adapter->unique_id);
+	return 0;
+}
+
+
+/**
+ * megaraid_mbox_mm_handler - interface for CMM to issue commands to LLD
+ * @drvr_data		: LLD specific data
+ * @kioc		: CMM interface packet
+ * @action		: command action
+ *
+ * This routine is invoked whenever the Common Management Module (CMM) has a
+ * command for us. The 'action' parameter specifies if this is a new command
+ * or otherwise.
+ */
+static int
+megaraid_mbox_mm_handler(unsigned long drvr_data, uioc_t *kioc, uint32_t action)
+{
+	adapter_t *adapter;
+
+	if (action != IOCTL_ISSUE) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: unsupported management action:%#2x\n",
+			action));
+		return (-ENOTSUPP);
+	}
+
+	adapter = (adapter_t *)drvr_data;
+
+	// make sure this adapter is not being detached right now.
+	if (atomic_read(&adapter->being_detached)) {
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: reject management request, detaching\n"));
+		return (-ENODEV);
+	}
+
+	switch (kioc->opcode) {
+
+	case GET_ADAP_INFO:
+
+		kioc->status =  gather_hbainfo(adapter, (mraid_hba_info_t *)
+					(unsigned long)kioc->buf_vaddr);
+
+		kioc->done(kioc);
+
+		return kioc->status;
+
+	case MBOX_CMD:
+
+		return megaraid_mbox_mm_command(adapter, kioc);
+
+	default:
+		kioc->status = (-EINVAL);
+		kioc->done(kioc);
+		return (-EINVAL);
+	}
+
+	return 0;	// not reached
+}
+
+/**
+ * megaraid_mbox_mm_command - issues commands routed through CMM
+ * @adapter		: HBA soft state
+ * @kioc		: management command packet
+ *
+ * Issues commands, which are routed through the management module.
+ */
+static int
+megaraid_mbox_mm_command(adapter_t *adapter, uioc_t *kioc)
+{
+	struct list_head	*head = &adapter->uscb_pool;
+	mbox64_t		*mbox64;
+	uint8_t			*raw_mbox;
+	scb_t			*scb;
+	mbox_ccb_t		*ccb;
+	unsigned long		flags;
+
+	// detach one scb from free pool
+	spin_lock_irqsave(USER_FREE_LIST_LOCK(adapter), flags);
+
+	if (list_empty(head)) {	// should never happen because of CMM
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid mbox: bug in cmm handler, lost resources\n"));
+
+		spin_unlock_irqrestore(USER_FREE_LIST_LOCK(adapter), flags);
+
+		return (-EINVAL);
+	}
+
+	scb = list_entry(head->next, scb_t, list);
+	list_del_init(&scb->list);
+
+	spin_unlock_irqrestore(USER_FREE_LIST_LOCK(adapter), flags);
+
+	scb->state		= SCB_ACTIVE;
+	scb->dma_type		= MRAID_DMA_NONE;
+	scb->dma_direction	= DMA_NONE;
+
+	ccb		= (mbox_ccb_t *)scb->ccb;
+	mbox64		= (mbox64_t *)(unsigned long)kioc->cmdbuf;
+	raw_mbox	= (uint8_t *)&mbox64->mbox32;
+
+	memcpy(ccb->mbox64, mbox64, sizeof(mbox64_t));
+
+	scb->gp		= (unsigned long)kioc;
+
+	/*
+	 * If it is a logdrv random delete operation, we have to wait till
+	 * there are no outstanding cmds at the fw and then issue it directly
+	 */
+	if (raw_mbox[0] == FC_DEL_LOGDRV && raw_mbox[2] == OP_DEL_LOGDRV) {
+
+		if (wait_till_fw_empty(adapter)) {
+			con_log(CL_ANN, (KERN_NOTICE
+				"megaraid mbox: LD delete, timed out\n"));
+
+			kioc->status = -ETIME;
+
+			scb->status = -1;
+
+			megaraid_mbox_mm_done(adapter, scb);
+
+			return (-ETIME);
+		}
+
+		INIT_LIST_HEAD(&scb->list);
+
+		scb->state = SCB_ISSUED;
+		if (mbox_post_cmd(adapter, scb) != 0) {
+
+			con_log(CL_ANN, (KERN_NOTICE
+				"megaraid mbox: LD delete, mailbox busy\n"));
+
+			kioc->status = -EBUSY;
+
+			scb->status = -1;
+
+			megaraid_mbox_mm_done(adapter, scb);
+
+			return (-EBUSY);
+		}
+
+		return 0;
+	}
+
+	// put the command on the pending list and execute
+	megaraid_mbox_runpendq(adapter, scb);
+
+	return 0;
+}
+
+
+static int
+wait_till_fw_empty(adapter_t *adapter)
+{
+	unsigned long	flags = 0;
+	int		i;
+
+
+	/*
+	 * Set the quiescent flag to stop issuing cmds to FW.
+	 */
+	spin_lock_irqsave(&adapter->lock, flags);
+	adapter->quiescent++;
+	spin_unlock_irqrestore(&adapter->lock, flags);
+
+	/*
+	 * Wait till there are no more cmds outstanding at FW. Try for at most
+	 * 60 seconds
+	 */
+	for (i = 0; i < 60 && adapter->outstanding_cmds; i++) {
+		con_log(CL_DLEVEL1, (KERN_INFO
+			"megaraid: FW has %d pending commands\n",
+			adapter->outstanding_cmds));
+
+		msleep(1000);
+	}
+
+	return adapter->outstanding_cmds;
+}
+
+
+/**
+ * megaraid_mbox_mm_done - callback for CMM commands
+ * @adapter	: HBA soft state
+ * @scb		: completed command
+ *
+ * Callback routine for internal commands originated from the management
+ * module.
+ */
+static void
+megaraid_mbox_mm_done(adapter_t *adapter, scb_t *scb)
+{
+	uioc_t			*kioc;
+	mbox64_t		*mbox64;
+	uint8_t			*raw_mbox;
+	unsigned long		flags;
+
+	kioc			= (uioc_t *)scb->gp;
+	mbox64			= (mbox64_t *)(unsigned long)kioc->cmdbuf;
+	mbox64->mbox32.status	= scb->status;
+	raw_mbox		= (uint8_t *)&mbox64->mbox32;
+
+
+	// put scb in the free pool
+	scb->state	= SCB_FREE;
+	scb->scp	= NULL;
+
+	spin_lock_irqsave(USER_FREE_LIST_LOCK(adapter), flags);
+
+	list_add(&scb->list, &adapter->uscb_pool);
+
+	spin_unlock_irqrestore(USER_FREE_LIST_LOCK(adapter), flags);
+
+	// if a delete logical drive operation succeeded, restart the
+	// controller
+	if (raw_mbox[0] == FC_DEL_LOGDRV && raw_mbox[2] == OP_DEL_LOGDRV) {
+
+		adapter->quiescent--;
+
+		megaraid_mbox_runpendq(adapter, NULL);
+	}
+
+	kioc->done(kioc);
+
+	return;
+}
+
+
+/**
+ * gather_hbainfo - HBA characteristics for the applications
+ * @adapter		: HBA soft state
+ * @hinfo		: pointer to the caller's host info strucuture
+ */
+static int
+gather_hbainfo(adapter_t *adapter, mraid_hba_info_t *hinfo)
+{
+	hinfo->pci_vendor_id	= adapter->pdev->vendor;
+	hinfo->pci_device_id	= adapter->pdev->device;
+	hinfo->subsys_vendor_id	= adapter->pdev->subsystem_vendor;
+	hinfo->subsys_device_id	= adapter->pdev->subsystem_device;
+
+	hinfo->pci_bus		= adapter->pdev->bus->number;
+	hinfo->pci_dev_fn	= adapter->pdev->devfn;
+	hinfo->pci_slot		= PCI_SLOT(adapter->pdev->devfn);
+	hinfo->irq		= adapter->host->irq;
+	hinfo->baseport		= ADAP2RAIDDEV(adapter)->baseport;
+
+	hinfo->unique_id	= (hinfo->pci_bus << 8) | adapter->pdev->devfn;
+	hinfo->host_no		= adapter->host->host_no;
+
+	return 0;
+}
+
+/*
+ * END: Interface for the common management module
+ */
+
+
+
+/**
+ * megaraid_sysfs_alloc_resources - allocate sysfs related resources
+ * @adapter	: controller's soft state
+ *
+ * Allocate packets required to issue FW calls whenever the sysfs attributes
+ * are read. These attributes would require up-to-date information from the
+ * FW. Also set up resources for mutual exclusion to share these resources and
+ * the wait queue.
+ *
+ * Return 0 on success.
+ * Return -ERROR_CODE on failure.
+ */
+static int
+megaraid_sysfs_alloc_resources(adapter_t *adapter)
+{
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+	int		rval = 0;
+
+	raid_dev->sysfs_uioc = kmalloc(sizeof(uioc_t), GFP_KERNEL);
+
+	raid_dev->sysfs_mbox64 = kmalloc(sizeof(mbox64_t), GFP_KERNEL);
+
+	raid_dev->sysfs_buffer = dma_alloc_coherent(&adapter->pdev->dev,
+			PAGE_SIZE, &raid_dev->sysfs_buffer_dma, GFP_KERNEL);
+
+	if (!raid_dev->sysfs_uioc || !raid_dev->sysfs_mbox64 ||
+		!raid_dev->sysfs_buffer) {
+
+		con_log(CL_ANN, (KERN_WARNING
+			"megaraid: out of memory, %s %d\n", __func__,
+			__LINE__));
+
+		rval = -ENOMEM;
+
+		megaraid_sysfs_free_resources(adapter);
+	}
+
+	mutex_init(&raid_dev->sysfs_mtx);
+
+	init_waitqueue_head(&raid_dev->sysfs_wait_q);
+
+	return rval;
+}
+
+
+/**
+ * megaraid_sysfs_free_resources - free sysfs related resources
+ * @adapter	: controller's soft state
+ *
+ * Free packets allocated for sysfs FW commands
+ */
+static void
+megaraid_sysfs_free_resources(adapter_t *adapter)
+{
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+
+	kfree(raid_dev->sysfs_uioc);
+	kfree(raid_dev->sysfs_mbox64);
+
+	if (raid_dev->sysfs_buffer) {
+		dma_free_coherent(&adapter->pdev->dev, PAGE_SIZE,
+			raid_dev->sysfs_buffer, raid_dev->sysfs_buffer_dma);
+	}
+}
+
+
+/**
+ * megaraid_sysfs_get_ldmap_done - callback for get ldmap
+ * @uioc	: completed packet
+ *
+ * Callback routine called in the ISR/tasklet context for get ldmap call
+ */
+static void
+megaraid_sysfs_get_ldmap_done(uioc_t *uioc)
+{
+	adapter_t	*adapter = (adapter_t *)uioc->buf_vaddr;
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+
+	uioc->status = 0;
+
+	wake_up(&raid_dev->sysfs_wait_q);
+}
+
+/**
+ * megaraid_sysfs_get_ldmap_timeout - timeout handling for get ldmap
+ * @t	: timed out timer
+ *
+ * Timeout routine to recover and return to application, in case the adapter
+ * has stopped responding. A timeout of 60 seconds for this command seems like
+ * a good value.
+ */
+static void
+megaraid_sysfs_get_ldmap_timeout(struct timer_list *t)
+{
+	struct uioc_timeout *timeout = from_timer(timeout, t, timer);
+	uioc_t		*uioc = timeout->uioc;
+	adapter_t	*adapter = (adapter_t *)uioc->buf_vaddr;
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+
+	uioc->status = -ETIME;
+
+	wake_up(&raid_dev->sysfs_wait_q);
+}
+
+
+/**
+ * megaraid_sysfs_get_ldmap - get update logical drive map
+ * @adapter	: controller's soft state
+ *
+ * This routine will be called whenever user reads the logical drive
+ * attributes, go get the current logical drive mapping table from the
+ * firmware. We use the management API's to issue commands to the controller.
+ *
+ * NOTE: The commands issuance functionality is not generalized and
+ * implemented in context of "get ld map" command only. If required, the
+ * command issuance logical can be trivially pulled out and implemented as a
+ * standalone library. For now, this should suffice since there is no other
+ * user of this interface.
+ *
+ * Return 0 on success.
+ * Return -1 on failure.
+ */
+static int
+megaraid_sysfs_get_ldmap(adapter_t *adapter)
+{
+	mraid_device_t		*raid_dev = ADAP2RAIDDEV(adapter);
+	uioc_t			*uioc;
+	mbox64_t		*mbox64;
+	mbox_t			*mbox;
+	char			*raw_mbox;
+	struct uioc_timeout	timeout;
+	caddr_t			ldmap;
+	int			rval = 0;
+
+	/*
+	 * Allow only one read at a time to go through the sysfs attributes
+	 */
+	mutex_lock(&raid_dev->sysfs_mtx);
+
+	uioc	= raid_dev->sysfs_uioc;
+	mbox64	= raid_dev->sysfs_mbox64;
+	ldmap	= raid_dev->sysfs_buffer;
+
+	memset(uioc, 0, sizeof(uioc_t));
+	memset(mbox64, 0, sizeof(mbox64_t));
+	memset(ldmap, 0, sizeof(raid_dev->curr_ldmap));
+
+	mbox		= &mbox64->mbox32;
+	raw_mbox	= (char *)mbox;
+	uioc->cmdbuf    = (uint64_t)(unsigned long)mbox64;
+	uioc->buf_vaddr	= (caddr_t)adapter;
+	uioc->status	= -ENODATA;
+	uioc->done	= megaraid_sysfs_get_ldmap_done;
+
+	/*
+	 * Prepare the mailbox packet to get the current logical drive mapping
+	 * table
+	 */
+	mbox->xferaddr = (uint32_t)raid_dev->sysfs_buffer_dma;
+
+	raw_mbox[0] = FC_DEL_LOGDRV;
+	raw_mbox[2] = OP_GET_LDID_MAP;
+
+	/*
+	 * Setup a timer to recover from a non-responding controller
+	 */
+	timeout.uioc = uioc;
+	timer_setup_on_stack(&timeout.timer,
+			     megaraid_sysfs_get_ldmap_timeout, 0);
+
+	timeout.timer.expires		= jiffies + 60 * HZ;
+	add_timer(&timeout.timer);
+
+	/*
+	 * Send the command to the firmware
+	 */
+	rval = megaraid_mbox_mm_command(adapter, uioc);
+
+	if (rval == 0) {	// command successfully issued
+		wait_event(raid_dev->sysfs_wait_q, (uioc->status != -ENODATA));
+
+		/*
+		 * Check if the command timed out
+		 */
+		if (uioc->status == -ETIME) {
+			con_log(CL_ANN, (KERN_NOTICE
+				"megaraid: sysfs get ld map timed out\n"));
+
+			rval = -ETIME;
+		}
+		else {
+			rval = mbox->status;
+		}
+
+		if (rval == 0) {
+			memcpy(raid_dev->curr_ldmap, ldmap,
+				sizeof(raid_dev->curr_ldmap));
+		}
+		else {
+			con_log(CL_ANN, (KERN_NOTICE
+				"megaraid: get ld map failed with %x\n", rval));
+		}
+	}
+	else {
+		con_log(CL_ANN, (KERN_NOTICE
+			"megaraid: could not issue ldmap command:%x\n", rval));
+	}
+
+
+	del_timer_sync(&timeout.timer);
+	destroy_timer_on_stack(&timeout.timer);
+
+	mutex_unlock(&raid_dev->sysfs_mtx);
+
+	return rval;
+}
+
+
+/**
+ * megaraid_mbox_app_hndl_show - display application handle for this adapter
+ * @dev		: class device object representation for the host
+ * @attr	: device attribute (unused)
+ * @buf		: buffer to send data to
+ *
+ * Display the handle used by the applications while executing management
+ * tasks on the adapter. We invoke a management module API to get the adapter
+ * handle, since we do not interface with applications directly.
+ */
+static ssize_t
+megaraid_mbox_app_hndl_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	adapter_t	*adapter = (adapter_t *)SCSIHOST2ADAP(shost);
+	uint32_t	app_hndl;
+
+	app_hndl = mraid_mm_adapter_app_handle(adapter->unique_id);
+
+	return sysfs_emit(buf, "%u\n", app_hndl);
+}
+
+
+/**
+ * megaraid_mbox_ld_show - display the logical drive number for this device
+ * @dev		: device object representation for the scsi device
+ * @attr	: device attribute to show
+ * @buf		: buffer to send data to
+ *
+ * Display the logical drive number for the device in question, if it a valid
+ * logical drive. For physical devices, "-1" is returned.
+ *
+ * The logical drive number is displayed in following format:
+ *
+ * <SCSI ID> <LD NUM> <LD STICKY ID> <APP ADAPTER HANDLE>
+ *
+ *   <int>     <int>       <int>            <int>
+ */
+static ssize_t
+megaraid_mbox_ld_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	adapter_t	*adapter = (adapter_t *)SCSIHOST2ADAP(sdev->host);
+	mraid_device_t	*raid_dev = ADAP2RAIDDEV(adapter);
+	int		scsi_id = -1;
+	int		logical_drv = -1;
+	int		ldid_map = -1;
+	uint32_t	app_hndl = 0;
+	int		mapped_sdev_id;
+	int		rval;
+	int		i;
+
+	if (raid_dev->random_del_supported &&
+			MRAID_IS_LOGICAL_SDEV(adapter, sdev)) {
+
+		rval = megaraid_sysfs_get_ldmap(adapter);
+		if (rval == 0) {
+
+			for (i = 0; i < MAX_LOGICAL_DRIVES_40LD; i++) {
+
+				mapped_sdev_id = sdev->id;
+
+				if (sdev->id > adapter->init_id) {
+					mapped_sdev_id -= 1;
+				}
+
+				if (raid_dev->curr_ldmap[i] == mapped_sdev_id) {
+
+					scsi_id = sdev->id;
+
+					logical_drv = i;
+
+					ldid_map = raid_dev->curr_ldmap[i];
+
+					app_hndl = mraid_mm_adapter_app_handle(
+							adapter->unique_id);
+
+					break;
+				}
+			}
+		}
+		else {
+			con_log(CL_ANN, (KERN_NOTICE
+				"megaraid: sysfs get ld map failed: %x\n",
+				rval));
+		}
+	}
+
+	return sysfs_emit(buf, "%d %d %d %d\n", scsi_id, logical_drv,
+			ldid_map, app_hndl);
+}
+
+
+/*
+ * END: Mailbox Low Level Driver
+ */
+module_init(megaraid_init);
+module_exit(megaraid_exit);