scsi: megaraid_sas: NVMe passthrough command support

NVMe passthrough via MFI interface. Current MegaRAID product supports
different types of encapsulation via the MFI framework.

NVMe native command should be framed by application and it should be
embedded in MFI as payload. The driver will provide interface to send
the MFI frame along with the payload (in this case, payload is NVMe
native command) to the firmware. Driver already has an existing, similar
interface for SATA and SMP passthrough.

1. Driver will pass MFI command to the firmware if the latter supports
   NVMe encapsulated processing (not all SAS3.5 firmware supports this
   feature).

2. Driver exposes sysfs entry support_nvme_encapsulation. This is
   required for backward compatibility for applications using earlier
   driver versions that did not process IOCTL frames and could result in
   host hang.

   This is already fixed as part of commit 82add4e1b354 ("scsi:
   megaraid_sas: Incorrect processing of IOCTL frames for SMP/STP
   commands")

[mkp: clarified commit message]

Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 29 insertions, 1 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index d92279e..0f1d88f 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -181,6 +181,7 @@ static DECLARE_WAIT_QUEUE_HEAD(megasas_poll_wait);
 static u32 support_poll_for_event;
 u32 megasas_dbg_lvl;
 static u32 support_device_change;
+static bool support_nvme_encapsulation;
 
 /* define lock for aen poll */
 spinlock_t poll_aen_lock;
@@ -3334,6 +3335,7 @@ megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd,
 
 	case MFI_CMD_SMP:
 	case MFI_CMD_STP:
+	case MFI_CMD_NVME:
 		megasas_complete_int_cmd(instance, cmd);
 		break;
 
@@ -4721,6 +4723,8 @@ megasas_get_ctrl_info(struct megasas_instance *instance)
 			ci->adapterOperations3.useSeqNumJbodFP;
 		instance->support_morethan256jbod =
 			ci->adapter_operations4.support_pd_map_target_id;
+		instance->support_nvme_passthru =
+			ci->adapter_operations4.support_nvme_passthru;
 
 		/*Check whether controller is iMR or MR */
 		instance->is_imr = (ci->memory_size ? 0 : 1);
@@ -4737,6 +4741,8 @@ megasas_get_ctrl_info(struct megasas_instance *instance)
 			instance->disableOnlineCtrlReset ? "Disabled" : "Enabled");
 		dev_info(&instance->pdev->dev, "Secure JBOD support\t: %s\n",
 			instance->secure_jbod_support ? "Yes" : "No");
+		dev_info(&instance->pdev->dev, "NVMe passthru support\t: %s\n",
+			 instance->support_nvme_passthru ? "Yes" : "No");
 		break;
 
 	case DCMD_TIMEOUT:
@@ -7110,7 +7116,9 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
 		return -EINVAL;
 	}
 
-	if (ioc->frame.hdr.cmd >= MFI_CMD_OP_COUNT) {
+	if ((ioc->frame.hdr.cmd >= MFI_CMD_OP_COUNT) ||
+	    ((ioc->frame.hdr.cmd == MFI_CMD_NVME) &&
+	    !instance->support_nvme_passthru)) {
 		dev_err(&instance->pdev->dev,
 			"Received invalid ioctl command 0x%x\n",
 			ioc->frame.hdr.cmd);
@@ -7580,6 +7588,14 @@ static ssize_t dbg_lvl_store(struct device_driver *dd, const char *buf,
 }
 static DRIVER_ATTR_RW(dbg_lvl);
 
+static ssize_t
+support_nvme_encapsulation_show(struct device_driver *dd, char *buf)
+{
+	return sprintf(buf, "%u\n", support_nvme_encapsulation);
+}
+
+static DRIVER_ATTR_RO(support_nvme_encapsulation);
+
 static inline void megasas_remove_scsi_device(struct scsi_device *sdev)
 {
 	sdev_printk(KERN_INFO, sdev, "SCSI device is removed\n");
@@ -7768,6 +7784,7 @@ static int __init megasas_init(void)
 
 	support_poll_for_event = 2;
 	support_device_change = 1;
+	support_nvme_encapsulation = true;
 
 	memset(&megasas_mgmt_info, 0, sizeof(megasas_mgmt_info));
 
@@ -7817,8 +7834,17 @@ static int __init megasas_init(void)
 	if (rval)
 		goto err_dcf_support_device_change;
 
+	rval = driver_create_file(&megasas_pci_driver.driver,
+				  &driver_attr_support_nvme_encapsulation);
+	if (rval)
+		goto err_dcf_support_nvme_encapsulation;
+
 	return rval;
 
+err_dcf_support_nvme_encapsulation:
+	driver_remove_file(&megasas_pci_driver.driver,
+			   &driver_attr_support_device_change);
+
 err_dcf_support_device_change:
 	driver_remove_file(&megasas_pci_driver.driver,
 			   &driver_attr_dbg_lvl);
@@ -7851,6 +7877,8 @@ static void __exit megasas_exit(void)
 	driver_remove_file(&megasas_pci_driver.driver,
 			   &driver_attr_release_date);
 	driver_remove_file(&megasas_pci_driver.driver, &driver_attr_version);
+	driver_remove_file(&megasas_pci_driver.driver,
+			   &driver_attr_support_nvme_encapsulation);
 
 	pci_unregister_driver(&megasas_pci_driver);
 	unregister_chrdev(megasas_mgmt_majorno, "megaraid_sas_ioctl");