scsi: ufs: Add API to execute raw upiu commands

The UFS host software uses a combination of a host register set and
Transfer Request Descriptors in system memory to communicate with host
controller hardware. In its mmio space, a separate places are assigned
to UTP Transfer Request Descriptor ("utrd") list, and to UTP Task
Management Request Descriptor ("utmrd") list.

The provided API supports utrd-typed requests: nop out and device
management commands. It also supports utmrd-type requests:
task management requests. Other UPIU types are not supported for now.

We utilize the already existing code for tag and task work queues.
That is, all utrd-typed UPIUs are "disguised" as device management
commands. Similarly, the utmrd-typed UPUIs uses the task management
infrastructure.

It is up to the caller to fill the upiu request properly, as it will be
copied without any further input validations.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index f5800c3203b0..58087d3916d0 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -414,6 +414,7 @@ enum {
 	MASK_RSP_UPIU_DATA_SEG_LEN	= 0xFFFF,
 	MASK_RSP_EXCEPTION_EVENT        = 0x10000,
 	MASK_TM_SERVICE_RESP		= 0xFF,
+	MASK_TM_FUNC			= 0xFF,
 };
 
 /* Task management service response */