@@ -13,6 +13,7 @@
#include <linux/uio.h>
#include <linux/dax.h>
#include <linux/fs.h>
+#include <linux/cacheinfo.h>
#include "dax-private.h"
/**
@@ -456,9 +457,7 @@ struct dax_device *alloc_dax(void *priva
* except for device-dax (NULL operations pointer), which does
* not use aliased mappings from the kernel.
*/
- if (ops && (IS_ENABLED(CONFIG_ARM) ||
- IS_ENABLED(CONFIG_MIPS) ||
- IS_ENABLED(CONFIG_SPARC)))
+ if (ops && cpu_dcache_is_aliasing())
return ERR_PTR(-EOPNOTSUPP);
if (WARN_ON_ONCE(ops && !ops->zero_page_range))
The patch titled Subject: dax: Fix incorrect list of data cache aliasing architectures has been added to the -mm mm-unstable branch. Its filename is dax-fix-incorrect-list-of-data-cache-aliasing-architectures.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/dax-fix-incorrect-list-of-data-cache-aliasing-architectures.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Subject: dax: Fix incorrect list of data cache aliasing architectures Date: Thu, 15 Feb 2024 09:46:33 -0500 commit d92576f1167c ("dax: does not work correctly with virtual aliasing caches") prevents DAX from building on architectures with virtually aliased dcache with: depends on !(ARM || MIPS || SPARC) This check is too broad (e.g. recent ARMv7 don't have virtually aliased dcaches), and also misses many other architectures with virtually aliased data cache. This is a regression introduced in the v4.0 Linux kernel where the dax mount option is removed for 32-bit ARMv7 boards which have no data cache aliasing, and therefore should work fine with FS_DAX. This was turned into the following check in alloc_dax() by a preparatory change: if (ops && (IS_ENABLED(CONFIG_ARM) || IS_ENABLED(CONFIG_MIPS) || IS_ENABLED(CONFIG_SPARC))) return NULL; Use cpu_dcache_is_aliasing() instead to figure out whether the environment has aliasing data caches. Link: https://lkml.kernel.org/r/20240215144633.96437-10-mathieu.desnoyers@efficios.com Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Alasdair Kergon <agk@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: kernel test robot <lkp@intel.com> Cc: Michael Sclafani <dm-devel@lists.linux.dev> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- drivers/dax/super.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)