megaraid_sas: JBOD sequence number support
Implemented JBOD map which will provide quick access for JBOD path and also provide sequence number. This will help hardware to fail command to the FW in case of any sequence mismatch. Fast Path I/O for JBOD will refer JBOD map (which has sequence number per JBOD device) instead of RAID map. Previously, the driver used RAID map to get device handle for fast path I/O and this not have sequence number information. Now, driver will use JBOD map instead. As part of error handling, if JBOD map is failed/not supported by firmware, driver will continue using legacy behavior. Now there will be three IO paths for JBOD (syspd): - JBOD map with sequence number (Fast Path) - RAID map without sequence number (Fast Path) - FW path via h/w exception queue deliberately setup devhandle 0xFFFF (FW path). Relevant data structures: - Driver send new DCMD MR_DCMD_SYSTEM_PD_MAP_GET_INFO for this purpose. - struct MR_PD_CFG_SEQ- This structure represent map of single physical device. - struct MR_PD_CFG_SEQ_NUM_SYNC- This structure represent whole JBOD map in general(size, count of sysPDs configured, struct MR_PD_CFG_SEQ of syspD with 0 index). - JBOD sequence map size is: sizeof(struct MR_PD_CFG_SEQ_NUM_SYNC) + (sizeof(struct MR_PD_CFG_SEQ) * (MAX_PHYSICAL_DEVICES - 1)) which is allocated while setting up JBOD map at driver load time. Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com> Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com> Reviewed-by: Martin Petersen <martin.petersen@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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