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 dcache.
This is a regression introduced in the v5.13 Linux kernel where the
dax mount option is removed for 32-bit ARMv7 boards which have no dcache
aliasing, and therefore should work fine with FS_DAX.
This was turned into the following implementation of dax_is_supported()
by a preparatory change:
return !IS_ENABLED(CONFIG_ARM) &&
!IS_ENABLED(CONFIG_MIPS) &&
!IS_ENABLED(CONFIG_SPARC);
Use dcache_is_aliasing() instead to figure out whether the environment
has aliasing dcaches.
Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing
caches")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: linux...@kvack.org
Cc: linux-a...@vger.kernel.org
Cc: Dan Williams <dan.j.willi...@intel.com>
Cc: Vishal Verma <vishal.l.ve...@intel.com>
Cc: Dave Jiang <dave.ji...@intel.com>
Cc: Matthew Wilcox <wi...@infradead.org>
Cc: Arnd Bergmann <a...@arndb.de>
Cc: Russell King <li...@armlinux.org.uk>
Cc: nvd...@lists.linux.dev
Cc: linux-...@vger.kernel.org
Cc: linux-fsde...@vger.kernel.org
---
include/linux/dax.h | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/include/linux/dax.h b/include/linux/dax.h
index cfc8cd4a3eae..f59e604662e4 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -5,6 +5,7 @@
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/radix-tree.h>
+#include <linux/cacheinfo.h>
typedef unsigned long dax_entry_t;
@@ -80,9 +81,7 @@ static inline bool daxdev_mapping_supported(struct
vm_area_struct *vma,
}
static inline bool dax_is_supported(void)
{
- return !IS_ENABLED(CONFIG_ARM) &&
- !IS_ENABLED(CONFIG_MIPS) &&
- !IS_ENABLED(CONFIG_SPARC);
+ return !dcache_is_aliasing();
}
#else
static inline void *dax_holder(struct dax_device *dax_dev)
--
2.39.2
