From db007fc5e20c00b356e9ffe2d0e007398c65c837 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Thu, 17 Jul 2008 04:28:31 -0400 Subject: [PATCH] [SCSI] Command protection operation Controllers that support DMA of protection information must be told explicitly how to handle the I/O. The controller has no knowledge of the protection capabilities of the target device so this information must be passed in the scsi_cmnd. - The protection operation tells the HBA whether to generate, strip or verify protection information. - The protection type tells the HBA which layout the target is formatted with. This is necessary because the controller must be able to correctly interpret the included protection information in order to verify it. - When a scsi_cmnd is reused for error handling the protection operation must be cleared and saved while error handling is in progress. - prot_op and prot_type are placed in an existing hole in scsi_cmnd and don't cause the structure to grow. Signed-off-by: Martin K. Petersen Signed-off-by: James Bottomley --- drivers/scsi/scsi_error.c | 3 ++ include/scsi/scsi_cmnd.h | 66 +++++++++++++++++++++++++++++++++++++++ include/scsi/scsi_eh.h | 1 + 3 files changed, 70 insertions(+) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 006a95916f72..a69397fd314a 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -664,7 +664,9 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses, ses->sdb = scmd->sdb; ses->next_rq = scmd->request->next_rq; ses->result = scmd->result; + ses->prot_op = scmd->prot_op; + scmd->prot_op = SCSI_PROT_NORMAL; scmd->cmnd = ses->eh_cmnd; memset(scmd->cmnd, 0, BLK_MAX_CDB); memset(&scmd->sdb, 0, sizeof(scmd->sdb)); @@ -722,6 +724,7 @@ void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses) scmd->sdb = ses->sdb; scmd->request->next_rq = ses->next_rq; scmd->result = ses->result; + scmd->prot_op = ses->prot_op; } EXPORT_SYMBOL(scsi_eh_restore_cmnd); diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index 66c944849d6b..402c1078d01c 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -77,6 +77,9 @@ struct scsi_cmnd { int allowed; int timeout_per_command; + unsigned char prot_op; + unsigned char prot_type; + unsigned short cmd_len; enum dma_data_direction sc_data_direction; @@ -208,4 +211,67 @@ static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *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, + + /* OS-HBA: Protected, HBA-Target: Protected, checksum conversion */ + SCSI_PROT_READ_CONVERT, + SCSI_PROT_WRITE_CONVERT, +}; + +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; +} + +/* + * 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 scmd->request->sector; +} + #endif /* _SCSI_SCSI_CMND_H */ diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h index 2a9add21267d..e5499ed0e376 100644 --- a/include/scsi/scsi_eh.h +++ b/include/scsi/scsi_eh.h @@ -75,6 +75,7 @@ struct scsi_eh_save { int result; enum dma_data_direction data_direction; unsigned char cmd_len; + unsigned char prot_op; unsigned char *cmnd; struct scsi_data_buffer sdb; struct request *next_rq;