From: Vineet Gupta <vgupta@kernel.org>
Date: Mon, 16 Sep 2019 17:54:34 +0000 (-0700)
Subject: ARC: mm: move MMU specific bits out of entry code ...
X-Git-Tag: microblaze-v5.16~88^2~8
X-Git-Url: http://git.monstr.eu/?p=linux-2.6-microblaze.git;a=commitdiff_plain;h=a79a9c765f95a73e087f11f0994297cd69987bda

ARC: mm: move MMU specific bits out of entry code ...

... to avoid polluting shared entry code (across three ISA variants)
with ISA/MMU specific code.

Cc: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
---

diff --git a/arch/arc/include/asm/mmu.h b/arch/arc/include/asm/mmu.h
index c8b490175eae..e66e1e417694 100644
--- a/arch/arc/include/asm/mmu.h
+++ b/arch/arc/include/asm/mmu.h
@@ -84,6 +84,14 @@ static inline int is_pae40_enabled(void)
 
 extern int pae40_exist_but_not_enab(void);
 
+#else
+
+.macro ARC_MMU_REENABLE reg
+	lr \reg, [ARC_REG_PID]
+	or \reg, \reg, MMU_ENABLE
+	sr \reg, [ARC_REG_PID]
+.endm
+
 #endif	/* !__ASSEMBLY__ */
 
 #endif
diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S
index 12d5f12d10d2..a7e6a2174187 100644
--- a/arch/arc/kernel/entry-arcv2.S
+++ b/arch/arc/kernel/entry-arcv2.S
@@ -10,6 +10,7 @@
 #include <asm/errno.h>
 #include <asm/arcregs.h>
 #include <asm/irqflags.h>
+#include <asm/mmu.h>
 
 ; A maximum number of supported interrupts in the core interrupt controller.
 ; This number is not equal to the maximum interrupt number (256) because
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 2cb8dfe866b6..dd77a0c8f740 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -101,11 +101,8 @@ ENTRY(EV_MachineCheck)
 	lr  r0, [efa]
 	mov r1, sp
 
-	; hardware auto-disables MMU, re-enable it to allow kernel vaddr
-	; access for say stack unwinding of modules for crash dumps
-	lr	r3, [ARC_REG_PID]
-	or	r3, r3, MMU_ENABLE
-	sr	r3, [ARC_REG_PID]
+	; MC excpetions disable MMU
+	ARC_MMU_REENABLE r3
 
 	lsr  	r3, r2, 8
 	bmsk 	r3, r3, 7