[PATCH] MIPS: smp-cps: Ensure secondary cores start with EVA disabled

[Matt Redfearn <matt.redfearn@imgtec.com>]

The kernel currently assumes that a core will start up in legacy mode
using the exception base provided through the CM GCR registers. If a
core has been configured in hardware to start in EVA mode, these
assumptions will fail.

This patch ensures that secondary cores are initialized to meet these
assumptions.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---
 arch/mips/include/asm/mips-cm.h | 4 ++++
 arch/mips/kernel/smp-cps.c      | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
index 1f1927ab4269..0dc8618aeb5e 100644
--- a/arch/mips/include/asm/mips-cm.h
+++ b/arch/mips/include/asm/mips-cm.h
@@ -230,6 +230,10 @@ BUILD_CM_Cx_R_(tcid_8_priority,	0x80)
 #define  CM_GCR_BASE_CMDEFTGT_IOCU0		2
 #define  CM_GCR_BASE_CMDEFTGT_IOCU1		3
 
+/* GCR_RESET_EXT_BASE register fields */
+#define CM_GCR_RESET_EXT_BASE_EVARESET		BIT(31)
+#define CM_GCR_RESET_EXT_BASE_UEB		BIT(30)
+
 /* GCR_ACCESS register fields */
 #define CM_GCR_ACCESS_ACCESSEN_SHF		0
 #define CM_GCR_ACCESS_ACCESSEN_MSK		(_ULCAST_(0xff) << 0)
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index c88937745b4e..db1da4d905b4 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -201,6 +201,9 @@ static void boot_core(unsigned core)
 	/* Ensure its coherency is disabled */
 	write_gcr_co_coherence(0);
 
+	/* Start it with the legacy memory map and exception base */
+	write_gcr_co_reset_ext_base(CM_GCR_RESET_EXT_BASE_UEB);
+
 	/* Ensure the core can access the GCRs */
 	access = read_gcr_access();
 	access |= 1 << (CM_GCR_ACCESS_ACCESSEN_SHF + core);
-- 
2.1.4