linux-stable/drivers/target
Bodo Stroesser 3c58f73723 scsi: target: tcmu: Optimize use of flush_dcache_page
(scatter|gather)_data_area() need to flush dcache after writing data to or
before reading data from a page in uio data area.  The two routines are
able to handle data transfer to/from such a page in fragments and flush the
cache after each fragment was copied by calling the wrapper
tcmu_flush_dcache_range().

That means:

1) flush_dcache_page() can be called multiple times for the same page.

2) Calling flush_dcache_page() indirectly using the wrapper does not make
   sense, because each call of the wrapper is for one single page only and
   the calling routine already has the correct page pointer.

Change (scatter|gather)_data_area() such that, instead of calling
tcmu_flush_dcache_range() before/after each memcpy, it now calls
flush_dcache_page() before unmapping a page (when writing is complete for
that page) or after mapping a page (when starting to read the page).

After this change only calls to tcmu_flush_dcache_range() for addresses in
vmalloc'ed command ring are left over.

The patch was tested on ARM with kernel 4.19.118 and 5.7.2

Link: https://lore.kernel.org/r/20200618131632.32748-2-bstroesser@ts.fujitsu.com
Tested-by: JiangYu <lnsyyj@hotmail.com>
Tested-by: Daniel Meyerholt <dxm523@gmail.com>
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-06-19 23:22:47 -04:00
..
iscsi Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
loopback scsi: target: loopback: Fix READ with data and sensebytes 2020-05-11 22:20:19 -04:00
sbp treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
tcm_fc scsi: libfc: remove unnecessary assertion on ep variable 2019-12-19 22:08:55 -05:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile
target_core_alua.c scsi: target: Make transport_flags per device 2020-05-07 22:39:21 -04:00
target_core_alua.h
target_core_configfs.c scsi: target: tcmu: Make pgr_support and alua_support attributes writable 2020-05-07 22:39:22 -04:00
target_core_device.c scsi: target: Initialize LUN in transport_init_se_cmd() 2020-06-09 21:57:26 -04:00
target_core_fabric_configfs.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
target_core_fabric_lib.c scsi: target: fix PR IN / READ FULL STATUS for FC 2020-04-13 14:00:41 -04:00
target_core_file.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
target_core_file.h
target_core_hba.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
target_core_iblock.c scsi: target/iblock: fix WRITE SAME zeroing 2020-04-22 00:02:13 -04:00
target_core_iblock.h
target_core_internal.h scsi: target/core: Make ABORT and LUN RESET handling synchronous 2018-12-07 21:22:55 -05:00
target_core_pr.c scsi: target: Make transport_flags per device 2020-05-07 22:39:21 -04:00
target_core_pr.h scsi: target/core: Rework the SPC-2 reservation handling code 2019-04-12 20:20:05 -04:00
target_core_pscsi.c scsi: target: Make transport_flags per device 2020-05-07 22:39:21 -04:00
target_core_pscsi.h
target_core_rd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
target_core_rd.h
target_core_sbc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
target_core_spc.c scsi: target: use an enum to track emulate_ua_intlck_ctrl 2020-02-21 17:37:16 -05:00
target_core_stat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
target_core_tmr.c scsi: target: Initialize LUN in transport_init_se_cmd() 2020-06-09 21:57:26 -04:00
target_core_tpg.c scsi: target: Make transport_flags per device 2020-05-07 22:39:21 -04:00
target_core_transport.c SCSI misc on 20200613 2020-06-13 13:17:49 -07:00
target_core_ua.c scsi: target: use an enum to track emulate_ua_intlck_ctrl 2020-02-21 17:37:16 -05:00
target_core_ua.h
target_core_user.c scsi: target: tcmu: Optimize use of flush_dcache_page 2020-06-19 23:22:47 -04:00
target_core_xcopy.c scsi: target: Rename target_setup_cmd_from_cdb() to target_cmd_parse_cdb() 2020-06-09 21:57:26 -04:00
target_core_xcopy.h scsi: target: use the stack for XCOPY passthrough cmds 2020-03-29 18:10:59 -04:00