From: Alexey Brodkin <abrodkin@synopsys.com>
Date: Wed, 24 Dec 2014 14:00:29 +0000 (+0300)
Subject: arc: add dependences on MMU presence
X-Git-Tag: v2015.04-rc1~68^2~6
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=dcb431e723f132d0df63fb1e711042a6bbfc3a6a;p=u-boot

arc: add dependences on MMU presence

Depending on MMU presence in CPU there're differences in HW behavior.
For example address of instruction that caused exception is put in
ECR register if MMU exists and in ERET register otherwise.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Igor Guryanov <guryanov@synopsys.com>
---

diff --git a/arch/arc/config.mk b/arch/arc/config.mk
index e408800a91..5321987a56 100644
--- a/arch/arc/config.mk
+++ b/arch/arc/config.mk
@@ -21,6 +21,10 @@ ifeq ($(CROSS_COMPILE),)
 CROSS_COMPILE := $(ARC_CROSS_COMPILE)
 endif
 
+ifdef CONFIG_ARC_MMU_VER
+CONFIG_MMU = 1
+endif
+
 PLATFORM_CPPFLAGS += -ffixed-r25 -D__ARC__ -gdwarf-2
 
 # Needed for relocation
diff --git a/arch/arc/cpu/arc700/start.S b/arch/arc/cpu/arc700/start.S
index 4d505bfb7c..2318282bf4 100644
--- a/arch/arc/cpu/arc700/start.S
+++ b/arch/arc/cpu/arc700/start.S
@@ -78,6 +78,16 @@
 	PUSHAX	%erbta
 .endm
 
+.macro SAVE_EXCEPTION_SOURCE
+#ifdef CONFIG_MMU
+	/* If MMU exists exception faulting address is loaded in EFA reg */
+	lr	%r0, [%efa]
+#else
+	/* Otherwise in ERET (exception return) reg */
+	lr	%r0, [%eret]
+#endif
+.endm
+
 .align 4
 .globl _start
 _start:
@@ -102,13 +112,13 @@ _start:
 
 memory_error:
 	SAVE_ALL_SYS
-	lr	%r0, [%efa]
+	SAVE_EXCEPTION_SOURCE
 	mov	%r1, %sp
 	j	do_memory_error
 
 instruction_error:
 	SAVE_ALL_SYS
-	lr	%r0, [%efa]
+	SAVE_EXCEPTION_SOURCE
 	mov	%r1, %sp
 	j	do_instruction_error
 
@@ -119,7 +129,7 @@ interrupt_handler:
 
 EV_MachineCheck:
 	SAVE_ALL_SYS
-	lr	%r0, [%efa]
+	SAVE_EXCEPTION_SOURCE
 	mov	%r1, %sp
 	j	do_machine_check_fault
 
@@ -135,7 +145,7 @@ EV_TLBMissD:
 
 EV_TLBProtV:
 	SAVE_ALL_SYS
-	lr	%r0, [%efa]
+	SAVE_EXCEPTION_SOURCE
 	mov	%r1, %sp
 	j	do_tlb_prot_violation