[PATCH v2 16/40] xen/arm: introduce setup_mm_mappings

[Penny Zheng <Penny.Zheng@xxxxxxx>]

Function setup_pagetables is responsible for boot-time pagetable setup
in MMU system.
But in MPU system, we have already built up start-of-day Xen MPU memory region
mapping at the very beginning in assembly.

So in order to keep only one codeflow in arm/setup.c, setup_mm_mappings
, with a more generic name, is introduced and act as an empty stub in
MPU system.

Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>
Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
 xen/arch/arm/include/asm/mm.h     |  2 ++
 xen/arch/arm/include/asm/mm_mpu.h | 16 ++++++++++++++++
 xen/arch/arm/setup.c              |  2 +-
 3 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 xen/arch/arm/include/asm/mm_mpu.h

diff --git a/xen/arch/arm/include/asm/mm.h b/xen/arch/arm/include/asm/mm.h
index 1b9fdb6ff5..9b4c07d965 100644
--- a/xen/arch/arm/include/asm/mm.h
+++ b/xen/arch/arm/include/asm/mm.h
@@ -243,6 +243,8 @@ static inline void __iomem *ioremap_wc(paddr_t start, 
size_t len)
 
 #ifndef CONFIG_HAS_MPU
 #include <asm/mm_mmu.h>
+#else
+#include <asm/mm_mpu.h>
 #endif
 
 /* Page-align address and convert to frame number format */
diff --git a/xen/arch/arm/include/asm/mm_mpu.h 
b/xen/arch/arm/include/asm/mm_mpu.h
new file mode 100644
index 0000000000..1f3cff7743
--- /dev/null
+++ b/xen/arch/arm/include/asm/mm_mpu.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __ARCH_ARM_MM_MPU__
+#define __ARCH_ARM_MM_MPU__
+
+#define setup_mm_mappings(boot_phys_offset) ((void)(boot_phys_offset))
+
+#endif /* __ARCH_ARM_MM_MPU__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 1f26f67b90..d7d200179c 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -1003,7 +1003,7 @@ void __init start_xen(unsigned long boot_phys_offset,
     /* Initialize traps early allow us to get backtrace when an error occurred 
*/
     init_traps();
 
-    setup_pagetables(boot_phys_offset);
+    setup_mm_mappings(boot_phys_offset);
 
     smp_clear_cpu_maps();
 
-- 
2.25.1