Prior to this change x86_64 used the pmem defines in
arch/x86/include/asm/pmem.h, and UM used the default ones at the
top of include/linux/pmem.h.  The inclusion or exclusion in linux/pmem.h
was controlled by CONFIG_ARCH_HAS_PMEM_API, but the ones in asm/pmem.h
were controlled by ARCH_HAS_NOCACHE_UACCESS.

Instead, control them both with CONFIG_ARCH_HAS_PMEM_API so that it's
clear that they are related and we don't run into the possibility where
they are both included or excluded.  Also remove a bunch of stale
function prototypes meant for UM in asm/pmem.h - these just conflicted
with the inline defaults in linux/pmem.h and gave compile errors.
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Prior to this change arch_has_wmb_pmem() was only called by
arch_has_pmem_api().  Both arch_has_wmb_pmem() and arch_has_pmem_api()
checked to make sure that CONFIG_ARCH_HAS_PMEM_API was enabled.

Instead, remove the old arch_has_wmb_pmem() wrapper to be rid of one
extra layer of indirection and the redundant CONFIG_ARCH_HAS_PMEM_API
check. Rename __arch_has_wmb_pmem() to arch_has_wmb_pmem() since we no
longer have a wrapper, and just have arch_has_pmem_api() call the
architecture specific arch_has_wmb_pmem() directly.
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Move the x86 PMEM API implementation out of asm/cacheflush.h and into
its own header asm/pmem.h.  This will allow members of the PMEM API to
be more easily identified on this and other architectures.
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>