AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2025-02-25 16:39:39 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity
7e83747dc9
linux_dsm_epyc7002/drivers/s390/scsi
History
Steffen Maier b63195698d scsi: zfcp: fix sysfs block queue limit output for max_segment_size 
Since v2.6.35 commit 683229845f ("[SCSI] zfcp: Report scatter-gather
limits to SCSI and block layer"), zfcp set dma_parms.max_segment_size ==
PAGE_SIZE (but without using the setter dma_set_max_seg_size()) and
scsi_host_template.dma_boundary == PAGE_SIZE - 1.

v5.0-rc1 commit 50c2e9107f ("scsi: introduce a max_segment_size
host_template parameters") introduced a new field
scsi_host_template.max_segment_size. If an LLDD such as zfcp does not set
it, scsi_host_alloc() uses BLK_MAX_SEGMENT_SIZE = 65536 for
Scsi_Host.max_segment_size. __scsi_init_queue() announced the minimum of
Scsi_Host.max_segment_size and dma_parms.max_segment_size to the block
layer. For zfcp: min(65536, 4096) == 4096 which was still good.

v5.0 commit a8cf59a669 ("scsi: communicate max segment size to the DMA
mapping code") announces Scsi_Host.max_segment_size to the block layer and
overwrites dma_parms.max_segment_size with Scsi_Host.max_segment_size.  For
zfcp dma_parms.max_segment_size == Scsi_Host.max_segment_size == 65536
which is also reflected in block queue limits.

$ cd /sys/bus/ccw/drivers/zfcp
$ cd 0.0.3c40/host5/rport-5:0-4/target5:0:4/5:0:4:10/block/sdi/queue
$ cat max_segment_size
65536

Zfcp I/O still works because dma_boundary implicitly still keeps the
effective max segment size <= PAGE_SIZE.  However, dma_boundary does not
seem visible to user space, but max_segment_size is visible and shows a
misleading wrong value.  Fix it and inherit the stable tag of a8cf59a669.

Devices on our bus ccw support DMA but no DMA mapping. Of multiple device
types on the ccw bus, only zfcp needs dma_parms for SCSI limits.  So, leave
dma_parms setup in zfcp and do not move it to the bus.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 50c2e9107f ("scsi: introduce a max_segment_size host_template parameters")
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-01-29 01:14:59 -05:00
..
Makefile s390: add a few more SPDX identifiers 2017-12-05 07:51:09 +01:00
zfcp_aux.c scsi: zfcp: fix sysfs block queue limit output for max_segment_size 2019-01-29 01:14:59 -05:00
zfcp_ccw.c
zfcp_dbf.c scsi: zfcp: silence all W=1 build warnings for existing kdoc 2018-11-15 15:01:18 -05:00
zfcp_dbf.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_def.h scsi: zfcp: use enum zfcp_erp_steps for struct zfcp_erp_action.step 2018-11-15 15:01:18 -05:00
zfcp_erp.c scsi: zfcp: drop old default switch case which might paper over missing case 2018-11-15 15:01:18 -05:00
zfcp_ext.h scsi: zfcp: make DIX experimental, disabled, and independent of DIF 2018-12-07 21:36:40 -05:00
zfcp_fc.c scsi: zfcp: silence all W=1 build warnings for existing kdoc 2018-11-15 15:01:18 -05:00
zfcp_fc.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_fsf.c scsi: zfcp: silence all W=1 build warnings for existing kdoc 2018-11-15 15:01:18 -05:00
zfcp_fsf.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_qdio.c scsi: zfcp: silence all W=1 build warnings for existing kdoc 2018-11-15 15:01:18 -05:00
zfcp_qdio.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_reqlist.h scsi: zfcp: silence remaining kdoc warnings in header files 2018-11-15 15:01:18 -05:00
zfcp_scsi.c scsi: zfcp: fix sysfs block queue limit output for max_segment_size 2019-01-29 01:14:59 -05:00
zfcp_sysfs.c scsi: zfcp: support SCSI_ADAPTER_RESET via scsi_host sysfs attribute host_reset 2018-05-18 11:28:15 -04:00
zfcp_unit.c