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scsi: sd: Create helper functions for read/write commands
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Create a helper function for each of the 6, 10, 16 and 32-byte READ/WRITE
variants and use those when setting up reads and writes.

Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
[ bvanassche: ported this patch from kernel v4.11 to kernel v5.0 and made
  function names shorter. ]
Signed-off-by: Bart Van Assche <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
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@martinkpetersen
martinkpetersen committed Jan 23, 2019
1 parent ec02975 commit 78a02f4
Showing 1 changed file with 92 additions and 75 deletions.
167 changes: 92 additions & 75 deletions drivers/scsi/sd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1072,6 +1072,83 @@ static blk_status_t sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
return BLK_STS_OK;
}

static blk_status_t sd_setup_rw32_cmnd(struct scsi_cmnd *cmd, bool write,
sector_t lba, unsigned int nr_blocks,
unsigned char flags)
{
cmd->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);
if (unlikely(cmd->cmnd == NULL))
return BLK_STS_RESOURCE;

cmd->cmd_len = SD_EXT_CDB_SIZE;
memset(cmd->cmnd, 0, cmd->cmd_len);

cmd->cmnd[0] = VARIABLE_LENGTH_CMD;
cmd->cmnd[7] = 0x18; /* Additional CDB len */
cmd->cmnd[9] = write ? WRITE_32 : READ_32;
cmd->cmnd[10] = flags;
put_unaligned_be64(lba, &cmd->cmnd[12]);
put_unaligned_be32(lba, &cmd->cmnd[20]); /* Expected Indirect LBA */
put_unaligned_be32(nr_blocks, &cmd->cmnd[28]);

return BLK_STS_OK;
}

static blk_status_t sd_setup_rw16_cmnd(struct scsi_cmnd *cmd, bool write,
sector_t lba, unsigned int nr_blocks,
unsigned char flags)
{
cmd->cmd_len = 16;
cmd->cmnd[0] = write ? WRITE_16 : READ_16;
cmd->cmnd[1] = flags;
cmd->cmnd[14] = 0;
cmd->cmnd[15] = 0;
put_unaligned_be64(lba, &cmd->cmnd[2]);
put_unaligned_be32(nr_blocks, &cmd->cmnd[10]);

return BLK_STS_OK;
}

static blk_status_t sd_setup_rw10_cmnd(struct scsi_cmnd *cmd, bool write,
sector_t lba, unsigned int nr_blocks,
unsigned char flags)
{
cmd->cmd_len = 10;
cmd->cmnd[0] = write ? WRITE_10 : READ_10;
cmd->cmnd[1] = flags;
cmd->cmnd[6] = 0;
cmd->cmnd[9] = 0;
put_unaligned_be32(lba, &cmd->cmnd[2]);
put_unaligned_be16(nr_blocks, &cmd->cmnd[7]);

return BLK_STS_OK;
}

static blk_status_t sd_setup_rw6_cmnd(struct scsi_cmnd *cmd, bool write,
sector_t lba, unsigned int nr_blocks,
unsigned char flags)
{
if (unlikely(flags & 0x8)) {
/*
* This happens only if this drive failed 10byte rw
* command with ILLEGAL_REQUEST during operation and
* thus turned off use_10_for_rw.
*/
scmd_printk(KERN_ERR, cmd, "FUA write on READ/WRITE(6) drive\n");
return BLK_STS_IOERR;
}

cmd->cmd_len = 6;
cmd->cmnd[0] = write ? WRITE_6 : READ_6;
cmd->cmnd[1] = (lba >> 16) & 0x1f;
cmd->cmnd[2] = (lba >> 8) & 0xff;
cmd->cmnd[3] = lba & 0xff;
cmd->cmnd[4] = nr_blocks;
cmd->cmnd[5] = 0;

return BLK_STS_OK;
}

static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
{
struct request *rq = SCpnt->request;
Expand All @@ -1083,7 +1160,8 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
unsigned int nr_blocks = sectors_to_logical(sdp, blk_rq_sectors(rq));
unsigned int dif, dix;
unsigned int mask = logical_to_sectors(sdp, 1) - 1;
unsigned char protect;
bool write = rq_data_dir(rq) == WRITE;
unsigned char protect, fua;
blk_status_t ret;

ret = scsi_init_io(SCpnt);
Expand Down Expand Up @@ -1158,6 +1236,7 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
"writing" : "reading", nr_blocks,
blk_rq_sectors(rq)));

fua = rq->cmd_flags & REQ_FUA ? 0x8 : 0;
dix = scsi_prot_sg_count(SCpnt);
dif = scsi_host_dif_capable(SCpnt->device->host, sdkp->protection_type);

Expand All @@ -1167,86 +1246,24 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
protect = 0;

if (protect && sdkp->protection_type == T10_PI_TYPE2_PROTECTION) {
SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);

if (unlikely(!SCpnt->cmnd))
return BLK_STS_RESOURCE;

SCpnt->cmd_len = SD_EXT_CDB_SIZE;
memset(SCpnt->cmnd, 0, SCpnt->cmd_len);
SCpnt->cmnd[0] = VARIABLE_LENGTH_CMD;
SCpnt->cmnd[7] = 0x18;
SCpnt->cmnd[9] = (rq_data_dir(rq) == READ) ? READ_32 : WRITE_32;
SCpnt->cmnd[10] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);

/* LBA */
SCpnt->cmnd[12] = sizeof(lba) > 4 ? (unsigned char) (lba >> 56) & 0xff : 0;
SCpnt->cmnd[13] = sizeof(lba) > 4 ? (unsigned char) (lba >> 48) & 0xff : 0;
SCpnt->cmnd[14] = sizeof(lba) > 4 ? (unsigned char) (lba >> 40) & 0xff : 0;
SCpnt->cmnd[15] = sizeof(lba) > 4 ? (unsigned char) (lba >> 32) & 0xff : 0;
SCpnt->cmnd[16] = (unsigned char) (lba >> 24) & 0xff;
SCpnt->cmnd[17] = (unsigned char) (lba >> 16) & 0xff;
SCpnt->cmnd[18] = (unsigned char) (lba >> 8) & 0xff;
SCpnt->cmnd[19] = (unsigned char) lba & 0xff;

/* Expected Indirect LBA */
SCpnt->cmnd[20] = (unsigned char) (lba >> 24) & 0xff;
SCpnt->cmnd[21] = (unsigned char) (lba >> 16) & 0xff;
SCpnt->cmnd[22] = (unsigned char) (lba >> 8) & 0xff;
SCpnt->cmnd[23] = (unsigned char) lba & 0xff;

/* Transfer length */
SCpnt->cmnd[28] = (unsigned char) (nr_blocks >> 24) & 0xff;
SCpnt->cmnd[29] = (unsigned char) (nr_blocks >> 16) & 0xff;
SCpnt->cmnd[30] = (unsigned char) (nr_blocks >> 8) & 0xff;
SCpnt->cmnd[31] = (unsigned char) nr_blocks & 0xff;
ret = sd_setup_rw32_cmnd(SCpnt, write, lba, nr_blocks,
protect | fua);
} else if (sdp->use_16_for_rw || (nr_blocks > 0xffff)) {
SCpnt->cmnd[0] += READ_16 - READ_6;
SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
SCpnt->cmnd[2] = sizeof(lba) > 4 ? (unsigned char) (lba >> 56) & 0xff : 0;
SCpnt->cmnd[3] = sizeof(lba) > 4 ? (unsigned char) (lba >> 48) & 0xff : 0;
SCpnt->cmnd[4] = sizeof(lba) > 4 ? (unsigned char) (lba >> 40) & 0xff : 0;
SCpnt->cmnd[5] = sizeof(lba) > 4 ? (unsigned char) (lba >> 32) & 0xff : 0;
SCpnt->cmnd[6] = (unsigned char) (lba >> 24) & 0xff;
SCpnt->cmnd[7] = (unsigned char) (lba >> 16) & 0xff;
SCpnt->cmnd[8] = (unsigned char) (lba >> 8) & 0xff;
SCpnt->cmnd[9] = (unsigned char) lba & 0xff;
SCpnt->cmnd[10] = (unsigned char) (nr_blocks >> 24) & 0xff;
SCpnt->cmnd[11] = (unsigned char) (nr_blocks >> 16) & 0xff;
SCpnt->cmnd[12] = (unsigned char) (nr_blocks >> 8) & 0xff;
SCpnt->cmnd[13] = (unsigned char) nr_blocks & 0xff;
SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
ret = sd_setup_rw16_cmnd(SCpnt, write, lba, nr_blocks,
protect | fua);
} else if ((nr_blocks > 0xff) || (lba > 0x1fffff) ||
scsi_device_protection(SCpnt->device) ||
SCpnt->device->use_10_for_rw) {
SCpnt->cmnd[0] += READ_10 - READ_6;
SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
SCpnt->cmnd[2] = (unsigned char) (lba >> 24) & 0xff;
SCpnt->cmnd[3] = (unsigned char) (lba >> 16) & 0xff;
SCpnt->cmnd[4] = (unsigned char) (lba >> 8) & 0xff;
SCpnt->cmnd[5] = (unsigned char) lba & 0xff;
SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
SCpnt->cmnd[7] = (unsigned char) (nr_blocks >> 8) & 0xff;
SCpnt->cmnd[8] = (unsigned char) nr_blocks & 0xff;
ret = sd_setup_rw10_cmnd(SCpnt, write, lba, nr_blocks,
protect | fua);
} else {
if (unlikely(rq->cmd_flags & REQ_FUA)) {
/*
* This happens only if this drive failed
* 10byte rw command with ILLEGAL_REQUEST
* during operation and thus turned off
* use_10_for_rw.
*/
scmd_printk(KERN_ERR, SCpnt,
"FUA write on READ/WRITE(6) drive\n");
return BLK_STS_IOERR;
}

SCpnt->cmnd[1] |= (unsigned char) ((lba >> 16) & 0x1f);
SCpnt->cmnd[2] = (unsigned char) ((lba >> 8) & 0xff);
SCpnt->cmnd[3] = (unsigned char) lba & 0xff;
SCpnt->cmnd[4] = (unsigned char) nr_blocks;
SCpnt->cmnd[5] = 0;
ret = sd_setup_rw6_cmnd(SCpnt, write, lba, nr_blocks,
protect | fua);
}

if (unlikely(ret != BLK_STS_OK))
return ret;

SCpnt->sdb.length = nr_blocks * sdp->sector_size;

/*
Expand Down

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