kernel/linux.git/drivers/s390/block/Kconfig, branch linux-7.0.y

s390/dcssblk: Add DAX support

2025-09-16T14:56:39+00:00

With ZONE_DEVICE now available for s390, struct pages can be allocated for proper DAX support in dcssblk driver via devm_memremap_pages(). Adding struct pages for a range requires that the range is aligned to SUBSECTION_SIZE, which is defined as 2 MB in common code. Therefore, only enable DAX support and allocate struct pages for DCSS ranges that are aligned to 2 MB. Signed-off-by: Gerald Schaefer Acked-by: Heiko Carstens Reviewed-by: Alexander Gordeev Signed-off-by: Alexander Gordeev

s390/dcssblk: Fix build error with CONFIG_DAX=m and CONFIG_DCSSBLK=y

2025-05-05T13:46:34+00:00

After commit 653d7825c149 ("dcssblk: mark DAX broken, remove FS_DAX_LIMITED support") moved the "select DAX" from config DCSSBLK to the new config DCSSBLK_DAX, randconfig tests could result in build errors like this: s390-linux-ld: drivers/s390/block/dcssblk.o: in function `dcssblk_shared_store': drivers/s390/block/dcssblk.c:417: undefined reference to `kill_dax' s390-linux-ld: drivers/s390/block/dcssblk.c:418: undefined reference to `put_dax' This is because it's now possible to have CONFIG_DCSSBLK=y, but CONFIG_DAX=m. Fix this by adding "depends on DAX || DAX=n" to config DCSSBLK, to make it explicit that we want either no DAX, or the same "y/m" for both config DAX and DCSSBLK, similar to config BLK_DEV_DM. This also requires removing the "select DAX" from config DCSSBLK_DAX, or else there would be a recursive dependency detected. DCSSBLK_DAX is marked as BROKEN at the moment, and won't work well with DAX anyway, so it doesn't really matter if it is selected. Fixes: 653d7825c149 ("dcssblk: mark DAX broken, remove FS_DAX_LIMITED support") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202504291604.pvjonhWX-lkp@intel.com/ Signed-off-by: Gerald Schaefer Signed-off-by: Heiko Carstens

dcssblk: mark DAX broken, remove FS_DAX_LIMITED support

2025-03-18T05:06:40+00:00

The dcssblk driver has long needed special case supoprt to enable limited dax operation, so called CONFIG_FS_DAX_LIMITED. This mode works around the incomplete support for ZONE_DEVICE on s390 by forgoing the ability of dax-mapped pages to support GUP. Now, pending cleanups to fsdax that fix its reference counting [1] depend on the ability of all dax drivers to supply ZONE_DEVICE pages. To allow that work to move forward, dax support needs to be paused for dcssblk until ZONE_DEVICE support arrives. That work has been known for a few years [2], and the removal of "pte_devmap" requirements [3] makes the conversion easier. For now, place the support behind CONFIG_BROKEN, and remove PFN_SPECIAL (dcssblk was the only user). Link: http://lore.kernel.org/cover.9f0e45d52f5cff58807831b6b867084d0b14b61c.1725941415.git-series.apopple@nvidia.com [1] Link: http://lore.kernel.org/20210820210318.187742e8@thinkpad/ [2] Link: http://lore.kernel.org/4511465a4f8429f45e2ac70d2e65dc5e1df1eb47.1725941415.git-series.apopple@nvidia.com [3] Link: https://lkml.kernel.org/r/33eef2379c0d240f40cc15453fad2df1a4ae34c8.1740713401.git-series.apopple@nvidia.com Signed-off-by: Dan Williams Reviewed-by: Gerald Schaefer Tested-by: Alexander Gordeev Acked-by: David Hildenbrand Tested-by: Alison Schofield Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Jan Kara Cc: Matthew Wilcox Cc: Christoph Hellwig Cc: Alistair Popple Cc: Asahi Lina Cc: Balbir Singh Cc: Bjorn Helgaas Cc: Catalin Marinas Cc: Chunyan Zhang Cc: "Darrick J. Wong" Cc: Dave Chinner Cc: Dave Hansen Cc: Dave Jiang Cc: Huacai Chen Cc: Ira Weiny Cc: Jason Gunthorpe Cc: Jason Gunthorpe Cc: John Hubbard Cc: linmiaohe Cc: Logan Gunthorpe Cc: Michael "Camp Drill Sergeant" Ellerman Cc: Nicholas Piggin Cc: Peter Xu Cc: Ted Ts'o Cc: Vishal Verma Cc: Vivek Goyal Cc: WANG Xuerui Cc: Will Deacon Signed-off-by: Andrew Morton

dax: remove CONFIG_DAX_DRIVER

2021-12-04T16:58:51+00:00

CONFIG_DAX_DRIVER only selects CONFIG_DAX now, so remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Dan Williams Link: https://lore.kernel.org/r/20211129102203.2243509-4-hch@lst.de Signed-off-by: Dan Williams

s390: remove xpram device driver

2021-09-07T11:38:42+00:00

Support for expanded storage was only available until z13 and z/VM 6.3 respectively. However there haven't been any use cases a long time before for this device driver. Therefore remove it. Acked-by: Christian Borntraeger Signed-off-by: Heiko Carstens

s390/dasd: remove IOSCHED_DEADLINE from DASD Kconfig

2020-04-17T14:05:27+00:00

CONFIG_IOSCHED_DEADLINE was removed with commit f382fb0bcef4 ("block: remove legacy IO schedulers") and setting of the scheduler was removed with commit a5fd8ddce2af ("s390/dasd: remove setting of scheduler from driver"). So get rid of the select. Reported-by: Krzysztof Kozlowski Signed-off-by: Stefan Haberland Signed-off-by: Jens Axboe

s390/Kconfig: pedantic cleanups

2019-06-04T13:03:46+00:00

Formatting of Kconfig files doesn't look so pretty, so just take damp cloth and clean it up. Signed-off-by: Enrico Weigelt, metux IT consult Signed-off-by: Heiko Carstens

dax: introduce CONFIG_DAX_DRIVER

2018-04-03T12:41:19+00:00

In support of allowing device-mapper to compile out idle/dead code when there are no dax providers in the system, introduce the DAX_DRIVER symbol. This is selected by all leaf drivers that device-mapper might be layered on top. This allows device-mapper to conditionally 'select DAX' only when a provider is present. Cc: Martin Schwidefsky Cc: Heiko Carstens Reported-by: Bart Van Assche Reviewed-by: Mike Snitzer Signed-off-by: Dan Williams

dax: require 'struct page' by default for filesystem dax

2018-01-20T00:50:53+00:00

If a dax buffer from a device that does not map pages is passed to read(2) or write(2) as a target for direct-I/O it triggers SIGBUS. If gdb attempts to examine the contents of a dax buffer from a device that does not map pages it triggers SIGBUS. If fork(2) is called on a process with a dax mapping from a device that does not map pages it triggers SIGBUS. 'struct page' is required otherwise several kernel code paths break in surprising ways. Disable filesystem-dax on devices that do not map pages. In addition to needing pfn_to_page() to be valid we also require devmap pages. We need this to detect dax pages in the get_user_pages_fast() path and so that we can stop managing the VM_MIXEDMAP flag. For DAX drivers that have not supported get_user_pages() to date we allow them to opt-in to supporting DAX with the CONFIG_FS_DAX_LIMITED configuration option which requires ->direct_access() to return pfn_t_special() pfns. This leaves DAX support in brd disabled and scheduled for removal. Note that when the initial dax support was being merged a few years back there was concern that struct page was unsuitable for use with next generation persistent memory devices. The theoretical concern was that struct page access, being such a hotly used data structure in the kernel, would lead to media wear out. While that was a reasonable conservative starting position it has not held true in practice. We have long since committed to using devm_memremap_pages() to support higher order kernel functionality that needs get_user_pages() and pfn_to_page(). Cc: Jeff Moyer Cc: Ross Zwisler Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Martin Schwidefsky Cc: Heiko Carstens Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Reviewed-by: Gerald Schaefer Signed-off-by: Dan Williams

s390: add a few more SPDX identifiers

2017-12-05T06:51:09+00:00

Add the correct SPDX license to a few more files under arch/s390 and drivers/s390 which have been missed to far. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. Signed-off-by: Martin Schwidefsky