target/mips: Add segmentation control registers

The optional segmentation control registers CP0_SegCtl0, CP0_SegCtl1 &
CP0_SegCtl2 control the behaviour and required privilege of the legacy
virtual memory segments.

Add them to the CP0 interface so they can be read and written when
CP0_Config3.SC=1, and initialise them to describe the standard legacy
layout so they can be used in future patches regardless of whether they
are exposed to the guest.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c
index c52a407e86..526f8e4969 100644
--- a/target/mips/op_helper.c
+++ b/target/mips/op_helper.c
@@ -1322,6 +1322,30 @@ void helper_mtc0_pagegrain(CPUMIPSState *env, target_ulong arg1)
     restore_pamask(env);
 }
 
+void helper_mtc0_segctl0(CPUMIPSState *env, target_ulong arg1)
+{
+    CPUState *cs = CPU(mips_env_get_cpu(env));
+
+    env->CP0_SegCtl0 = arg1 & CP0SC0_MASK;
+    tlb_flush(cs);
+}
+
+void helper_mtc0_segctl1(CPUMIPSState *env, target_ulong arg1)
+{
+    CPUState *cs = CPU(mips_env_get_cpu(env));
+
+    env->CP0_SegCtl1 = arg1 & CP0SC1_MASK;
+    tlb_flush(cs);
+}
+
+void helper_mtc0_segctl2(CPUMIPSState *env, target_ulong arg1)
+{
+    CPUState *cs = CPU(mips_env_get_cpu(env));
+
+    env->CP0_SegCtl2 = arg1 & CP0SC2_MASK;
+    tlb_flush(cs);
+}
+
 void helper_mtc0_wired(CPUMIPSState *env, target_ulong arg1)
 {
     if (env->insn_flags & ISA_MIPS32R6) {