[Qemu-ppc] [PATCH v4 21/29] target-ppc: Enable FSCR facility check for TAR

[Alexey Kardashevskiy]

This makes user-privileged read/write fail if TAR facility is not enabled
in FSCR.

Since this is the very first check for enabled in FSCR facility,
this also adds gen_fscr_facility_check() for using in spr_write_tar()/
spr_read_tar().

Signed-off-by: Alexey Kardashevskiy <address@hidden>
---
 target-ppc/translate_init.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 6f0c36b..9b83d56 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -7275,6 +7275,21 @@ enum BOOK3S_CPU_TYPE {
     BOOK3S_CPU_POWER8
 };
 
+static void gen_fscr_facility_check(void *opaque, int facility_sprn, int bit,
+                                    int sprn, int cause)
+{
+    TCGv_i32 t1 = tcg_const_i32(bit);
+    TCGv_i32 t2 = tcg_const_i32(sprn);
+    TCGv_i32 t3 = tcg_const_i32(cause);
+
+    gen_update_current_nip(opaque);
+    gen_helper_fscr_facility_check(cpu_env, t1, t2, t3);
+
+    tcg_temp_free_i32(t3);
+    tcg_temp_free_i32(t2);
+    tcg_temp_free_i32(t1);
+}
+
 static int check_pow_970 (CPUPPCState *env)
 {
     if (env->spr[SPR_HID0] & 0x01C00000) {
@@ -7568,10 +7583,22 @@ static void gen_spr_power6_common(CPUPPCState *env)
                  0x00000000);
 }
 
+static void spr_read_tar(void *opaque, int gprn, int sprn)
+{
+    gen_fscr_facility_check(opaque, SPR_FSCR, FSCR_TAR, sprn, FSCR_IC_TAR);
+    spr_read_generic(opaque, gprn, sprn);
+}
+
+static void spr_write_tar(void *opaque, int sprn, int gprn)
+{
+    gen_fscr_facility_check(opaque, SPR_FSCR, FSCR_TAR, sprn, FSCR_IC_TAR);
+    spr_write_generic(opaque, sprn, gprn);
+}
+
 static void gen_spr_power8_tce_address_control(CPUPPCState *env)
 {
     spr_register(env, SPR_TAR, "TAR",
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_tar, &spr_write_tar,
                  &spr_read_generic, &spr_write_generic,
                  0x00000000);
 }
-- 
2.0.0