scsi: core: Introduce enums for the SAM and host status codes

Make it possible for the compiler to verify whether SAM and host
status codes are used correctly.

[mkp: resolve conflicts with Hannes' SCSI result series]

Link: https://lore.kernel.org/r/20210524025457.11299-3-bvanassche@acm.org
Cc: Hannes Reinecke <hare@suse.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/constants.c

@@ -408,8 +408,8 @@ static const char * const hostbyte_table[]={
 
 const char *scsi_hostbyte_string(int result)
 {
+	enum scsi_host_status hb = host_byte(result);
 	const char *hb_string = NULL;
-	int hb = host_byte(result);
 
 	if (hb < ARRAY_SIZE(hostbyte_table))
 		hb_string = hostbyte_table[hb];

drivers/target/target_core_pscsi.c

@@ -1044,7 +1044,7 @@ static void pscsi_req_done(struct request *req, blk_status_t status)
 	struct se_cmd *cmd = req->end_io_data;
 	struct pscsi_plugin_task *pt = cmd->priv;
 	int result = scsi_req(req)->result;
-	u8 scsi_status = result & 0xff;
+	enum sam_status scsi_status = result & 0xff;
 
 	if (scsi_status != SAM_STAT_GOOD) {
 		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"

include/scsi/scsi.h

@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <scsi/scsi_common.h>
 #include <scsi/scsi_proto.h>
+#include <scsi/scsi_status.h>
 
 struct scsi_cmnd;
 
@@ -79,78 +80,14 @@ static inline int scsi_status_is_check_condition(int status)
 }
 
 /*
- *  MESSAGE CODES
+ *  Extended message codes.
  */
-
-#define COMMAND_COMPLETE    0x00
-#define EXTENDED_MESSAGE    0x01
 #define     EXTENDED_MODIFY_DATA_POINTER    0x00
 #define     EXTENDED_SDTR                   0x01
 #define     EXTENDED_EXTENDED_IDENTIFY      0x02    /* SCSI-I only */
 #define     EXTENDED_WDTR                   0x03
 #define     EXTENDED_PPR                    0x04
 #define     EXTENDED_MODIFY_BIDI_DATA_PTR   0x05
-#define SAVE_POINTERS       0x02
-#define RESTORE_POINTERS    0x03
-#define DISCONNECT          0x04
-#define INITIATOR_ERROR     0x05
-#define ABORT_TASK_SET      0x06
-#define MESSAGE_REJECT      0x07
-#define NOP                 0x08
-#define MSG_PARITY_ERROR    0x09
-#define LINKED_CMD_COMPLETE 0x0a
-#define LINKED_FLG_CMD_COMPLETE 0x0b
-#define TARGET_RESET        0x0c
-#define ABORT_TASK          0x0d
-#define CLEAR_TASK_SET      0x0e
-#define INITIATE_RECOVERY   0x0f            /* SCSI-II only */
-#define RELEASE_RECOVERY    0x10            /* SCSI-II only */
-#define TERMINATE_IO_PROC   0x11            /* SCSI-II only */
-#define CLEAR_ACA           0x16
-#define LOGICAL_UNIT_RESET  0x17
-#define SIMPLE_QUEUE_TAG    0x20
-#define HEAD_OF_QUEUE_TAG   0x21
-#define ORDERED_QUEUE_TAG   0x22
-#define IGNORE_WIDE_RESIDUE 0x23
-#define ACA                 0x24
-#define QAS_REQUEST         0x55
-
-/* Old SCSI2 names, don't use in new code */
-#define BUS_DEVICE_RESET    TARGET_RESET
-#define ABORT               ABORT_TASK_SET
-
-/*
- * Host byte codes
- */
-
-#define DID_OK          0x00	/* NO error                                */
-#define DID_NO_CONNECT  0x01	/* Couldn't connect before timeout period  */
-#define DID_BUS_BUSY    0x02	/* BUS stayed busy through time out period */
-#define DID_TIME_OUT    0x03	/* TIMED OUT for other reason              */
-#define DID_BAD_TARGET  0x04	/* BAD target.                             */
-#define DID_ABORT       0x05	/* Told to abort for some other reason     */
-#define DID_PARITY      0x06	/* Parity error                            */
-#define DID_ERROR       0x07	/* Internal error                          */
-#define DID_RESET       0x08	/* Reset by somebody.                      */
-#define DID_BAD_INTR    0x09	/* Got an interrupt we weren't expecting.  */
-#define DID_PASSTHROUGH 0x0a	/* Force command past mid-layer            */
-#define DID_SOFT_ERROR  0x0b	/* The low level driver just wish a retry  */
-#define DID_IMM_RETRY   0x0c	/* Retry without decrementing retry count  */
-#define DID_REQUEUE	0x0d	/* Requeue command (no immediate retry) also
-				 * without decrementing the retry count	   */
-#define DID_TRANSPORT_DISRUPTED 0x0e /* Transport error disrupted execution
-				      * and the driver blocked the port to
-				      * recover the link. Transport class will
-				      * retry or fail IO */
-#define DID_TRANSPORT_FAILFAST	0x0f /* Transport class fastfailed the io */
-#define DID_TARGET_FAILURE 0x10 /* Permanent target failure, do not retry on
-				 * other paths */
-#define DID_NEXUS_FAILURE 0x11  /* Permanent nexus failure, retry on other
-				 * paths might yield different results */
-#define DID_ALLOC_FAILURE 0x12  /* Space allocation on the device failed */
-#define DID_MEDIUM_ERROR  0x13  /* Medium error */
-#define DID_TRANSPORT_MARGINAL 0x14 /* Transport marginal errors */
-#define DRIVER_OK       0x00	/* Driver status                           */
 
 /*
  * Internal return values.

include/scsi/scsi_proto.h

@@ -190,17 +190,19 @@ struct scsi_varlen_cdb_hdr {
  *  SCSI Architecture Model (SAM) Status codes. Taken from SAM-3 draft
  *  T10/1561-D Revision 4 Draft dated 7th November 2002.
  */
-#define SAM_STAT_GOOD            0x00
-#define SAM_STAT_CHECK_CONDITION 0x02
-#define SAM_STAT_CONDITION_MET   0x04
-#define SAM_STAT_BUSY            0x08
-#define SAM_STAT_INTERMEDIATE    0x10
-#define SAM_STAT_INTERMEDIATE_CONDITION_MET 0x14
-#define SAM_STAT_RESERVATION_CONFLICT 0x18
-#define SAM_STAT_COMMAND_TERMINATED 0x22	/* obsolete in SAM-3 */
-#define SAM_STAT_TASK_SET_FULL   0x28
-#define SAM_STAT_ACA_ACTIVE      0x30
-#define SAM_STAT_TASK_ABORTED    0x40
+enum sam_status {
+	SAM_STAT_GOOD				= 0x00,
+	SAM_STAT_CHECK_CONDITION		= 0x02,
+	SAM_STAT_CONDITION_MET			= 0x04,
+	SAM_STAT_BUSY				= 0x08,
+	SAM_STAT_INTERMEDIATE			= 0x10,
+	SAM_STAT_INTERMEDIATE_CONDITION_MET	= 0x14,
+	SAM_STAT_RESERVATION_CONFLICT		= 0x18,
+	SAM_STAT_COMMAND_TERMINATED		= 0x22,	/* obsolete in SAM-3 */
+	SAM_STAT_TASK_SET_FULL			= 0x28,
+	SAM_STAT_ACA_ACTIVE			= 0x30,
+	SAM_STAT_TASK_ABORTED			= 0x40,
+};
 
 #define STATUS_MASK         0xfe
 /*

include/scsi/scsi_status.h

@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _SCSI_SCSI_STATUS_H
+#define _SCSI_SCSI_STATUS_H
+
+#include <linux/types.h>
+#include <scsi/scsi_proto.h>
+
+/* Message codes. */
+enum scsi_msg_byte {
+	COMMAND_COMPLETE	= 0x00,
+	EXTENDED_MESSAGE	= 0x01,
+	SAVE_POINTERS		= 0x02,
+	RESTORE_POINTERS	= 0x03,
+	DISCONNECT		= 0x04,
+	INITIATOR_ERROR		= 0x05,
+	ABORT_TASK_SET		= 0x06,
+	MESSAGE_REJECT		= 0x07,
+	NOP			= 0x08,
+	MSG_PARITY_ERROR	= 0x09,
+	LINKED_CMD_COMPLETE	= 0x0a,
+	LINKED_FLG_CMD_COMPLETE	= 0x0b,
+	TARGET_RESET		= 0x0c,
+	ABORT_TASK		= 0x0d,
+	CLEAR_TASK_SET		= 0x0e,
+	INITIATE_RECOVERY	= 0x0f,            /* SCSI-II only */
+	RELEASE_RECOVERY	= 0x10,            /* SCSI-II only */
+	TERMINATE_IO_PROC	= 0x11,            /* SCSI-II only */
+	CLEAR_ACA		= 0x16,
+	LOGICAL_UNIT_RESET	= 0x17,
+	SIMPLE_QUEUE_TAG	= 0x20,
+	HEAD_OF_QUEUE_TAG	= 0x21,
+	ORDERED_QUEUE_TAG	= 0x22,
+	IGNORE_WIDE_RESIDUE	= 0x23,
+	ACA			= 0x24,
+	QAS_REQUEST		= 0x55,
+
+	/* Old SCSI2 names, don't use in new code */
+	BUS_DEVICE_RESET	= TARGET_RESET,
+	ABORT			= ABORT_TASK_SET,
+};
+
+/* Host byte codes. */
+enum scsi_host_status {
+	DID_OK		= 0x00,	/* NO error                                */
+	DID_NO_CONNECT	= 0x01,	/* Couldn't connect before timeout period  */
+	DID_BUS_BUSY	= 0x02,	/* BUS stayed busy through time out period */
+	DID_TIME_OUT	= 0x03,	/* TIMED OUT for other reason              */
+	DID_BAD_TARGET	= 0x04,	/* BAD target.                             */
+	DID_ABORT	= 0x05,	/* Told to abort for some other reason     */
+	DID_PARITY	= 0x06,	/* Parity error                            */
+	DID_ERROR	= 0x07,	/* Internal error                          */
+	DID_RESET	= 0x08,	/* Reset by somebody.                      */
+	DID_BAD_INTR	= 0x09,	/* Got an interrupt we weren't expecting.  */
+	DID_PASSTHROUGH	= 0x0a,	/* Force command past mid-layer            */
+	DID_SOFT_ERROR	= 0x0b,	/* The low level driver just wish a retry  */
+	DID_IMM_RETRY	= 0x0c,	/* Retry without decrementing retry count  */
+	DID_REQUEUE	= 0x0d,	/* Requeue command (no immediate retry) also
+				 * without decrementing the retry count	   */
+	DID_TRANSPORT_DISRUPTED = 0x0e, /* Transport error disrupted execution
+					 * and the driver blocked the port to
+					 * recover the link. Transport class will
+					 * retry or fail IO */
+	DID_TRANSPORT_FAILFAST = 0x0f, /* Transport class fastfailed the io */
+	DID_TARGET_FAILURE = 0x10, /* Permanent target failure, do not retry on
+				    * other paths */
+	DID_NEXUS_FAILURE = 0x11,  /* Permanent nexus failure, retry on other
+				    * paths might yield different results */
+	DID_ALLOC_FAILURE = 0x12,  /* Space allocation on the device failed */
+	DID_MEDIUM_ERROR = 0x13,  /* Medium error */
+	DID_TRANSPORT_MARGINAL = 0x14, /* Transport marginal errors */
+};
+
+#endif /* _SCSI_SCSI_STATUS_H */