diff options
Diffstat (limited to 'drivers/scsi/sd.c')
| -rw-r--r-- | drivers/scsi/sd.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index a1a44f52e0e8..c6ca3d915925 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -659,6 +659,68 @@ static int sd_sec_submit(void *data, u16 spsp, u8 secp, void *buffer, } #endif /* CONFIG_BLK_SED_OPAL */ +/* + * Look up the DIX operation based on whether the command is read or + * write and whether dix and dif are enabled. + */ +static unsigned int sd_prot_op(bool write, bool dix, bool dif) +{ + /* Lookup table: bit 2 (write), bit 1 (dix), bit 0 (dif) */ + static const unsigned int ops[] = { /* wrt dix dif */ + SCSI_PROT_NORMAL, /* 0 0 0 */ + SCSI_PROT_READ_STRIP, /* 0 0 1 */ + SCSI_PROT_READ_INSERT, /* 0 1 0 */ + SCSI_PROT_READ_PASS, /* 0 1 1 */ + SCSI_PROT_NORMAL, /* 1 0 0 */ + SCSI_PROT_WRITE_INSERT, /* 1 0 1 */ + SCSI_PROT_WRITE_STRIP, /* 1 1 0 */ + SCSI_PROT_WRITE_PASS, /* 1 1 1 */ + }; + + return ops[write << 2 | dix << 1 | dif]; +} + +/* + * Returns a mask of the protection flags that are valid for a given DIX + * operation. + */ +static unsigned int sd_prot_flag_mask(unsigned int prot_op) +{ + static const unsigned int flag_mask[] = { + [SCSI_PROT_NORMAL] = 0, + + [SCSI_PROT_READ_STRIP] = SCSI_PROT_TRANSFER_PI | + SCSI_PROT_GUARD_CHECK | + SCSI_PROT_REF_CHECK | + SCSI_PROT_REF_INCREMENT, + + [SCSI_PROT_READ_INSERT] = SCSI_PROT_REF_INCREMENT | + SCSI_PROT_IP_CHECKSUM, + + [SCSI_PROT_READ_PASS] = SCSI_PROT_TRANSFER_PI | + SCSI_PROT_GUARD_CHECK | + SCSI_PROT_REF_CHECK | + SCSI_PROT_REF_INCREMENT | + SCSI_PROT_IP_CHECKSUM, + + [SCSI_PROT_WRITE_INSERT] = SCSI_PROT_TRANSFER_PI | + SCSI_PROT_REF_INCREMENT, + + [SCSI_PROT_WRITE_STRIP] = SCSI_PROT_GUARD_CHECK | + SCSI_PROT_REF_CHECK | + SCSI_PROT_REF_INCREMENT | + SCSI_PROT_IP_CHECKSUM, + + [SCSI_PROT_WRITE_PASS] = SCSI_PROT_TRANSFER_PI | + SCSI_PROT_GUARD_CHECK | + SCSI_PROT_REF_CHECK | + SCSI_PROT_REF_INCREMENT | + SCSI_PROT_IP_CHECKSUM, + }; + + return flag_mask[prot_op]; +} + static unsigned char sd_setup_protect_cmnd(struct scsi_cmnd *scmd, unsigned int dix, unsigned int dif) { |