From: Vincenzo Frascino <vincenzo.frascino@arm.com>

[ Upstream commit 76950f7162cad51d2200ebd22c620c14af38f718 ]

To perform the reserve_crashkernel() operation kexec uses SECTION_SIZE to
find a memblock in a range.
SECTION_SIZE is not defined for nommu systems. Trying to compile kexec in
these conditions results in a build error:

  linux/arch/arm/kernel/setup.c: In function ‘reserve_crashkernel’:
  linux/arch/arm/kernel/setup.c:1016:25: error: ‘SECTION_SIZE’ undeclared
     (first use in this function); did you mean ‘SECTIONS_WIDTH’?
             crash_size, SECTION_SIZE);
                         ^~~~~~~~~~~~
                         SECTIONS_WIDTH
  linux/arch/arm/kernel/setup.c:1016:25: note: each undeclared identifier
     is reported only once for each function it appears in
  linux/scripts/Makefile.build:265: recipe for target 'arch/arm/kernel/setup.o'
     failed

Make KEXEC depend on MMU to fix the compilation issue.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Russell King <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ba9325fc75b85..7a8fbe9a077bb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig

@@ -2005,7 +2005,7 @@ config XIP_PHYS_ADDR
 config KEXEC
 	bool "Kexec system call (EXPERIMENTAL)"
 	depends on (!SMP || PM_SLEEP_SMP)
-	depends on !CPU_V7M
+	depends on MMU
 	select KEXEC_CORE
 	help
 	  kexec is a system call that implements the ability to shutdown your

-- 
2.20.1