[PATCH] mm/hmm: kconfig split HMM address space mirroring from device memory

[jglisse@redhat.com]

From: Jérôme Glisse <jglisse@redhat.com>

To allow building device driver that only care about address space
mirroring (like RDMA ODP) on platform that do not have all the pre-
requisite for HMM device memory (like ZONE_DEVICE on ARM) split the
HMM_MIRROR option dependency from the HMM_DEVICE dependency.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
---
 mm/Kconfig | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/mm/Kconfig b/mm/Kconfig
index 2e6d24d783f7..00d9febbc775 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -679,12 +679,13 @@ config ZONE_DEVICE
 config ARCH_HAS_HMM
 	bool
 	default y
-	depends on (X86_64 || PPC64)
-	depends on ZONE_DEVICE
 	depends on MMU && 64BIT
-	depends on MEMORY_HOTPLUG
-	depends on MEMORY_HOTREMOVE
-	depends on SPARSEMEM_VMEMMAP
+
+config ARCH_HAS_HMM_DEVICE
+	bool
+	default y
+	depends on (X86_64 || PPC64)
+	depends on ARCH_HAS_ZONE_DEVICE
 
 config MIGRATE_VMA_HELPER
 	bool
@@ -710,7 +711,8 @@ config HMM_MIRROR
 
 config DEVICE_PRIVATE
 	bool "Unaddressable device memory (GPU memory, ...)"
-	depends on ARCH_HAS_HMM
+	depends on ARCH_HAS_HMM_DEVICE
+	depends on ZONE_DEVICE
 	select HMM
 	select DEV_PAGEMAP_OPS
 
@@ -721,7 +723,8 @@ config DEVICE_PRIVATE
 
 config DEVICE_PUBLIC
 	bool "Addressable device memory (like GPU memory)"
-	depends on ARCH_HAS_HMM
+	depends on ARCH_HAS_HMM_DEVICE
+	depends on ZONE_DEVICE
 	select HMM
 	select DEV_PAGEMAP_OPS
 
-- 
2.20.1