[PATCH v1 2/4] smartpqi: add support for CCISS_BIG_PASSTHRU ioctl

[David Strahan <david.strahan@microchip.com>]

From: David Strahan <David.Strahan@microchip.com>

smartpqi: add support for CCISS_BIG_PASSTHRU ioctl

Add pqi_big_passthru_ioctl() to handle CCISS_BIG_PASSTHRU ioctl
requests. The existing passthru ioctl uses a 16-bit integer for
the I/O buffer size, limiting transfers to 64KB. The big passthru
ioctl uses BIG_IOCTL_Command_struct which stores the buffer size as
a 32-bit integer, allowing larger transfers required by some
management utilities.

Add CCISS_BIG_PASSTHRU_SUPPORTED to uapi/linux/cciss_ioctl.h and
return 0 from pqi_ioctl() to advertise driver support.
Userspace tools can send this ioctl to probe whether the driver
supports CCISS_BIG_PASSTHRU before issuing it.

Co-developed-by: Mike McGowen <mike.mcgowen@microchip.com>
Signed-off-by: Mike McGowen <mike.mcgowen@microchip.com>
Signed-off-by: David Strahan <david.strahan@microchip.com>
Acked-by: Don Brace <don.brace@microchip.com>
---
 drivers/scsi/smartpqi/smartpqi_init.c | 144 ++++++++++++++++++++++++++
 include/uapi/linux/cciss_ioctl.h      |   1 +
 2 files changed, 145 insertions(+)

diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index 3a75b9f..473f1c9 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -6935,6 +6935,144 @@ out:
 	return rc;
 }
 
+static int pqi_big_passthru_ioctl(struct pqi_ctrl_info *ctrl_info, void __user *arg)
+{
+	int rc;
+	char *kernel_buffer = NULL;
+	u16 iu_length;
+	size_t sense_data_length;
+	BIG_IOCTL_Command_struct iocommand;
+	struct pqi_raid_path_request request;
+	struct pqi_raid_error_info pqi_error_info;
+	struct ciss_error_info ciss_error_info;
+
+	if (pqi_ctrl_offline(ctrl_info))
+		return -ENXIO;
+	if (pqi_ofa_in_progress(ctrl_info) && pqi_ctrl_blocked(ctrl_info))
+		return -EBUSY;
+	if (!arg)
+		return -EINVAL;
+	if (!capable(CAP_SYS_RAWIO))
+		return -EPERM;
+	if (copy_from_user(&iocommand, arg, sizeof(iocommand)))
+		return -EFAULT;
+	if (iocommand.buf_size < 1 &&
+		iocommand.Request.Type.Direction != XFER_NONE)
+		return -EINVAL;
+	if (iocommand.Request.CDBLen > sizeof(request.cdb))
+		return -EINVAL;
+	if (iocommand.Request.Type.Type != TYPE_CMD)
+		return -EINVAL;
+
+	switch (iocommand.Request.Type.Direction) {
+	case XFER_NONE:
+	case XFER_WRITE:
+	case XFER_READ:
+	case XFER_READ | XFER_WRITE:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (iocommand.buf_size > 0) {
+		kernel_buffer = kmalloc(iocommand.buf_size, GFP_KERNEL);
+		if (!kernel_buffer)
+			return -ENOMEM;
+		if (iocommand.Request.Type.Direction & XFER_WRITE) {
+			if (copy_from_user(kernel_buffer, iocommand.buf,
+				iocommand.buf_size)) {
+				rc = -EFAULT;
+				goto out;
+			}
+		} else {
+			memset(kernel_buffer, 0, iocommand.buf_size);
+		}
+	}
+
+	memset(&request, 0, sizeof(request));
+
+	request.header.iu_type = PQI_REQUEST_IU_RAID_PATH_IO;
+	iu_length = offsetof(struct pqi_raid_path_request, sg_descriptors) -
+		PQI_REQUEST_HEADER_LENGTH;
+	memcpy(request.lun_number, iocommand.LUN_info.LunAddrBytes, sizeof(request.lun_number));
+	memcpy(request.cdb, iocommand.Request.CDB, iocommand.Request.CDBLen);
+	request.additional_cdb_bytes_usage = SOP_ADDITIONAL_CDB_BYTES_0;
+
+	switch (iocommand.Request.Type.Direction) {
+	case XFER_NONE:
+		request.data_direction = SOP_NO_DIRECTION_FLAG;
+		break;
+	case XFER_WRITE:
+		request.data_direction = SOP_WRITE_FLAG;
+		break;
+	case XFER_READ:
+		request.data_direction = SOP_READ_FLAG;
+		break;
+	case XFER_READ | XFER_WRITE:
+		request.data_direction = SOP_BIDIRECTIONAL;
+		break;
+	}
+
+	request.task_attribute = SOP_TASK_ATTRIBUTE_SIMPLE;
+
+	if (iocommand.buf_size > 0) {
+		put_unaligned_le32(iocommand.buf_size, &request.buffer_length);
+
+		rc = pqi_map_single(ctrl_info->pci_dev,
+			&request.sg_descriptors[0], kernel_buffer,
+			iocommand.buf_size, DMA_BIDIRECTIONAL);
+		if (rc)
+			goto out;
+
+		iu_length += sizeof(request.sg_descriptors[0]);
+	}
+
+	put_unaligned_le16(iu_length, &request.header.iu_length);
+
+	if (ctrl_info->raid_iu_timeout_supported)
+		put_unaligned_le32(iocommand.Request.Timeout, &request.timeout);
+
+	rc = pqi_submit_raid_request_synchronous(ctrl_info, &request.header,
+		PQI_SYNC_FLAGS_INTERRUPTABLE, &pqi_error_info);
+
+	if (iocommand.buf_size > 0)
+		pqi_pci_unmap(ctrl_info->pci_dev, request.sg_descriptors, 1, DMA_BIDIRECTIONAL);
+
+	memset(&iocommand.error_info, 0, sizeof(iocommand.error_info));
+
+	if (rc == 0) {
+		pqi_error_info_to_ciss(&pqi_error_info, &ciss_error_info);
+		iocommand.error_info.ScsiStatus = ciss_error_info.scsi_status;
+		iocommand.error_info.CommandStatus = ciss_error_info.command_status;
+		sense_data_length = ciss_error_info.sense_data_length;
+		if (sense_data_length) {
+			if (sense_data_length > sizeof(iocommand.error_info.SenseInfo))
+				sense_data_length = sizeof(iocommand.error_info.SenseInfo);
+			memcpy(iocommand.error_info.SenseInfo,
+				pqi_error_info.data, sense_data_length);
+			iocommand.error_info.SenseLen = sense_data_length;
+		}
+	}
+
+	if (copy_to_user(arg, &iocommand, sizeof(iocommand))) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	if (rc == 0 && iocommand.buf_size > 0 &&
+		(iocommand.Request.Type.Direction & XFER_READ)) {
+		if (copy_to_user(iocommand.buf, kernel_buffer,
+			iocommand.buf_size)) {
+			rc = -EFAULT;
+		}
+	}
+
+out:
+	kfree(kernel_buffer);
+
+	return rc;
+}
+
 static int pqi_ioctl(struct scsi_device *sdev, unsigned int cmd,
 		     void __user *arg)
 {
@@ -6958,6 +7096,12 @@ static int pqi_ioctl(struct scsi_device *sdev, unsigned int cmd,
 	case CCISS_PASSTHRU:
 		rc = pqi_passthru_ioctl(ctrl_info, arg);
 		break;
+	case CCISS_BIG_PASSTHRU:
+		rc = pqi_big_passthru_ioctl(ctrl_info, arg);
+		break;
+	case CCISS_BIG_PASSTHRU_SUPPORTED:
+		rc = 0;
+		break;
 	default:
 		rc = -EINVAL;
 		break;
diff --git a/include/uapi/linux/cciss_ioctl.h b/include/uapi/linux/cciss_ioctl.h
index 5622301..8295f1b 100644
--- a/include/uapi/linux/cciss_ioctl.h
+++ b/include/uapi/linux/cciss_ioctl.h
@@ -85,5 +85,6 @@ typedef struct _LogvolInfo_struct{
 #define CCISS_RESCANDISK   _IO(CCISS_IOC_MAGIC, 16)
 #define CCISS_GETLUNINFO   _IOR(CCISS_IOC_MAGIC, 17, LogvolInfo_struct)
 #define CCISS_BIG_PASSTHRU _IOWR(CCISS_IOC_MAGIC, 18, BIG_IOCTL_Command_struct)
+#define CCISS_BIG_PASSTHRU_SUPPORTED _IO(CCISS_IOC_MAGIC, 19)
 
 #endif /* _UAPICCISS_IOCTLH */
-- 
2.52.0