[PATCH v3 2/2] xen/mmu: enable SMMU subsystem only in MMU

[Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>]

From: Penny Zheng <Penny.Zheng@xxxxxxx>

In Xen, SMMU subsystem is supported for MMU system only. The reason being SMMU
driver uses the same page tables as MMU.
Thus, we make it dependent on CONFIG_MMU.

Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
---
Changes from 

v1 - 1. HAS_PASSTHROUGH is now enclosed within "config MMU".
There was a pending response on
"[PATCH v1 2/2] xen/mmu: enable SMMU subsystem only in MMU"
that it might introduce a bunch of #if-defs in arm specific common code.
However, there are alternative implementations possible to reduce
#if-defs. So, that can be decided at a later point in time and should
not block the current patch.

v2 - 1. Added Julien's A-b.

 xen/arch/arm/Kconfig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 23bbc91aad..604aba4996 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -15,9 +15,7 @@ config ARM
        select GENERIC_UART_INIT
        select HAS_ALTERNATIVE if HAS_VMAP
        select HAS_DEVICE_TREE
-       select HAS_PASSTHROUGH
        select HAS_UBSAN
-       select IOMMU_FORCE_PT_SHARE
 
 config ARCH_DEFCONFIG
        string
@@ -79,6 +77,8 @@ config MMU
        bool "MMU"
        select HAS_PMAP
        select HAS_VMAP
+       select HAS_PASSTHROUGH
+       select IOMMU_FORCE_PT_SHARE
        help
          Select it if you plan to run Xen on A-profile Armv7+
 
-- 
2.25.1