linux/include/scsi/scsi_cmnd.h
Hannes Reinecke 54cf31d07a scsi: core: Drop message byte helper
The message byte is now unused, so we can drop the helper to set the
message byte and the check for message bytes during error recovery.

Link: https://lore.kernel.org/r/20210427083046.31620-38-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31 22:48:24 -04:00

375 lines
9.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _SCSI_SCSI_CMND_H
#define _SCSI_SCSI_CMND_H
#include <linux/dma-mapping.h>
#include <linux/blkdev.h>
#include <linux/t10-pi.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/scatterlist.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_request.h>
struct Scsi_Host;
struct scsi_driver;
/*
* MAX_COMMAND_SIZE is:
* The longest fixed-length SCSI CDB as per the SCSI standard.
* fixed-length means: commands that their size can be determined
* by their opcode and the CDB does not carry a length specifier, (unlike
* the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
* true and the SCSI standard also defines extended commands and
* vendor specific commands that can be bigger than 16 bytes. The kernel
* will support these using the same infrastructure used for VARLEN CDB's.
* So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
* supports without specifying a cmd_len by ULD's
*/
#define MAX_COMMAND_SIZE 16
#if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
# error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
#endif
struct scsi_data_buffer {
struct sg_table table;
unsigned length;
};
/* embedded in scsi_cmnd */
struct scsi_pointer {
char *ptr; /* data pointer */
int this_residual; /* left in this buffer */
struct scatterlist *buffer; /* which buffer */
int buffers_residual; /* how many buffers left */
dma_addr_t dma_handle;
volatile int Status;
volatile int Message;
volatile int have_data_in;
volatile int sent_command;
volatile int phase;
};
/* for scmd->flags */
#define SCMD_TAGGED (1 << 0)
#define SCMD_INITIALIZED (1 << 1)
#define SCMD_LAST (1 << 2)
/* flags preserved across unprep / reprep */
#define SCMD_PRESERVED_FLAGS (SCMD_INITIALIZED)
/* for scmd->state */
#define SCMD_STATE_COMPLETE 0
#define SCMD_STATE_INFLIGHT 1
struct scsi_cmnd {
struct scsi_request req;
struct scsi_device *device;
struct list_head eh_entry; /* entry for the host eh_cmd_q */
struct delayed_work abort_work;
struct rcu_head rcu;
int eh_eflags; /* Used by error handlr */
int budget_token;
/*
* This is set to jiffies as it was when the command was first
* allocated. It is used to time how long the command has
* been outstanding
*/
unsigned long jiffies_at_alloc;
int retries;
int allowed;
unsigned char prot_op;
unsigned char prot_type;
unsigned char prot_flags;
unsigned short cmd_len;
enum dma_data_direction sc_data_direction;
/* These elements define the operation we are about to perform */
unsigned char *cmnd;
/* These elements define the operation we ultimately want to perform */
struct scsi_data_buffer sdb;
struct scsi_data_buffer *prot_sdb;
unsigned underflow; /* Return error if less than
this amount is transferred */
unsigned transfersize; /* How much we are guaranteed to
transfer with each SCSI transfer
(ie, between disconnect /
reconnects. Probably == sector
size */
struct request *request; /* The command we are
working on */
unsigned char *sense_buffer;
/* obtained by REQUEST SENSE when
* CHECK CONDITION is received on original
* command (auto-sense). Length must be
* SCSI_SENSE_BUFFERSIZE bytes. */
/* Low-level done function - can be used by low-level driver to point
* to completion function. Not used by mid/upper level code. */
void (*scsi_done) (struct scsi_cmnd *);
/*
* The following fields can be written to by the host specific code.
* Everything else should be left alone.
*/
struct scsi_pointer SCp; /* Scratchpad used by some host adapters */
unsigned char *host_scribble; /* The host adapter is allowed to
* call scsi_malloc and get some memory
* and hang it here. The host adapter
* is also expected to call scsi_free
* to release this memory. (The memory
* obtained by scsi_malloc is guaranteed
* to be at an address < 16Mb). */
int result; /* Status code from lower level driver */
int flags; /* Command flags */
unsigned long state; /* Command completion state */
unsigned char tag; /* SCSI-II queued command tag */
unsigned int extra_len; /* length of alignment and padding */
};
/*
* Return the driver private allocation behind the command.
* Only works if cmd_size is set in the host template.
*/
static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
{
return cmd + 1;
}
/* make sure not to use it with passthrough commands */
static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
{
return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
}
extern void scsi_finish_command(struct scsi_cmnd *cmd);
extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
size_t *offset, size_t *len);
extern void scsi_kunmap_atomic_sg(void *virt);
blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
void scsi_free_sgtables(struct scsi_cmnd *cmd);
#ifdef CONFIG_SCSI_DMA
extern int scsi_dma_map(struct scsi_cmnd *cmd);
extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
#else /* !CONFIG_SCSI_DMA */
static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
#endif /* !CONFIG_SCSI_DMA */
static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
{
return cmd->sdb.table.nents;
}
static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
{
return cmd->sdb.table.sgl;
}
static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
{
return cmd->sdb.length;
}
static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
{
cmd->req.resid_len = resid;
}
static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
{
return cmd->req.resid_len;
}
#define scsi_for_each_sg(cmd, sg, nseg, __i) \
for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
void *buf, int buflen)
{
return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
buf, buflen);
}
static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
void *buf, int buflen)
{
return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
buf, buflen);
}
/*
* The operations below are hints that tell the controller driver how
* to handle I/Os with DIF or similar types of protection information.
*/
enum scsi_prot_operations {
/* Normal I/O */
SCSI_PROT_NORMAL = 0,
/* OS-HBA: Protected, HBA-Target: Unprotected */
SCSI_PROT_READ_INSERT,
SCSI_PROT_WRITE_STRIP,
/* OS-HBA: Unprotected, HBA-Target: Protected */
SCSI_PROT_READ_STRIP,
SCSI_PROT_WRITE_INSERT,
/* OS-HBA: Protected, HBA-Target: Protected */
SCSI_PROT_READ_PASS,
SCSI_PROT_WRITE_PASS,
};
static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
{
scmd->prot_op = op;
}
static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
{
return scmd->prot_op;
}
enum scsi_prot_flags {
SCSI_PROT_TRANSFER_PI = 1 << 0,
SCSI_PROT_GUARD_CHECK = 1 << 1,
SCSI_PROT_REF_CHECK = 1 << 2,
SCSI_PROT_REF_INCREMENT = 1 << 3,
SCSI_PROT_IP_CHECKSUM = 1 << 4,
};
/*
* The controller usually does not know anything about the target it
* is communicating with. However, when DIX is enabled the controller
* must be know target type so it can verify the protection
* information passed along with the I/O.
*/
enum scsi_prot_target_type {
SCSI_PROT_DIF_TYPE0 = 0,
SCSI_PROT_DIF_TYPE1,
SCSI_PROT_DIF_TYPE2,
SCSI_PROT_DIF_TYPE3,
};
static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
{
scmd->prot_type = type;
}
static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
{
return scmd->prot_type;
}
static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
{
return blk_rq_pos(scmd->request);
}
static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
{
return scmd->device->sector_size;
}
static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
{
return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
}
static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
{
return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
}
static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
{
return cmd->prot_sdb;
}
#define scsi_for_each_prot_sg(cmd, sg, nseg, __i) \
for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
{
cmd->result = (cmd->result & 0xffffff00) | status;
}
static inline u8 get_status_byte(struct scsi_cmnd *cmd)
{
return cmd->result & 0xff;
}
static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
{
cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
}
static inline u8 get_host_byte(struct scsi_cmnd *cmd)
{
return (cmd->result >> 16) & 0xff;
}
/**
* scsi_msg_to_host_byte() - translate message byte
*
* Translate the SCSI parallel message byte to a matching
* host byte setting. A message of COMMAND_COMPLETE indicates
* a successful command execution, any other message indicate
* an error. As the messages themselves only have a meaning
* for the SCSI parallel protocol this function translates
* them into a matching host byte value for SCSI EH.
*/
static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
{
switch (msg) {
case COMMAND_COMPLETE:
break;
case ABORT_TASK_SET:
set_host_byte(cmd, DID_ABORT);
break;
case TARGET_RESET:
set_host_byte(cmd, DID_RESET);
break;
default:
set_host_byte(cmd, DID_ERROR);
break;
}
}
static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
{
unsigned int xfer_len = scmd->sdb.length;
unsigned int prot_interval = scsi_prot_interval(scmd);
if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
return xfer_len;
}
extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
u8 key, u8 asc, u8 ascq);
#endif /* _SCSI_SCSI_CMND_H */