[Qemu-devel] [PATCH 09/15] target-s390x: PER successful-branching event support

[Aurelien Jarno <aurelien@aurel32.net>]

For the PER successful-branching event support, we can't rely on any
QEMU infrastucture. We therefore call an helper in all places where
a branch can be taken. We have to pay attention to the branch to next
case, as it's still a taken branch.

We don't need to care about the cases using goto_tb, as we have disabled
them in the previous patch.

Cc: Alexander Graf <agraf@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 target-s390x/helper.h      |  1 +
 target-s390x/misc_helper.c | 11 +++++++++++
 target-s390x/translate.c   | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/target-s390x/helper.h b/target-s390x/helper.h
index 37bd4d7..8d89cff 100644
--- a/target-s390x/helper.h
+++ b/target-s390x/helper.h
@@ -117,4 +117,5 @@ DEF_HELPER_FLAGS_2(lurag, TCG_CALL_NO_WG, i64, env, i64)
 DEF_HELPER_FLAGS_3(stura, TCG_CALL_NO_WG, void, env, i64, i64)
 DEF_HELPER_FLAGS_3(sturg, TCG_CALL_NO_WG, void, env, i64, i64)
 DEF_HELPER_1(per_check_exception, void, env)
+DEF_HELPER_FLAGS_3(per_branch, TCG_CALL_NO_RWG, void, env, i64, i64)
 #endif
diff --git a/target-s390x/misc_helper.c b/target-s390x/misc_helper.c
index d19ae91..8972929 100644
--- a/target-s390x/misc_helper.c
+++ b/target-s390x/misc_helper.c
@@ -508,4 +508,15 @@ void HELPER(per_check_exception)(CPUS390XState *env)
         cpu_loop_exit(cs);
     }
 }
+
+void HELPER(per_branch)(CPUS390XState *env, uint64_t from, uint64_t to)
+{
+    if ((env->cregs[9] & PER_CR9_EVENT_BRANCH)) {
+        if (!(env->cregs[9] & PER_CR9_CONTROL_BRANCH_ADDRESS)
+            || get_per_in_range(env, to)) {
+            env->per_address = from;
+            env->per_perc_atmid = PER_CODE_EVENT_BRANCH | get_per_atmid(env);
+        }
+    }
+}
 #endif
diff --git a/target-s390x/translate.c b/target-s390x/translate.c
index ff2c4bb..897486c 100644
--- a/target-s390x/translate.c
+++ b/target-s390x/translate.c
@@ -249,6 +249,38 @@ static void update_psw_addr(DisasContext *s)
     tcg_gen_movi_i64(psw_addr, s->pc);
 }
 
+static void per_branch(DisasContext *s, bool to_next)
+{
+#ifndef CONFIG_USER_ONLY
+    if (s->tb->flags & FLAG_MASK_PER) {
+        TCGv_i64 pc = tcg_const_i64(s->pc);
+        TCGv_i64 next_pc = to_next ? tcg_const_i64(s->next_pc) : psw_addr;
+        gen_helper_per_branch(cpu_env, pc, next_pc);
+        if (to_next) {
+            tcg_temp_free_i64(next_pc);
+        }
+        tcg_temp_free_i64(pc);
+    }
+#endif
+}
+
+static void per_branch_cond(DisasContext *s, TCGCond cond,
+                            TCGv_i64 arg1, TCGv_i64 arg2)
+{
+#ifndef CONFIG_USER_ONLY
+    if (s->tb->flags & FLAG_MASK_PER) {
+        TCGLabel *lab = gen_new_label();
+        tcg_gen_brcond_i64(tcg_invert_cond(cond), arg1, arg2, lab);
+
+        TCGv_i64 pc = tcg_const_i64(s->pc);
+        gen_helper_per_branch(cpu_env, pc, psw_addr);
+        tcg_temp_free_i64(pc);
+
+        gen_set_label(lab);
+    }
+#endif
+}
+
 static void update_cc_op(DisasContext *s)
 {
     if (s->cc_op != CC_OP_DYNAMIC && s->cc_op != CC_OP_STATIC) {
@@ -1182,6 +1214,7 @@ static void help_l2_shift(DisasContext *s, DisasFields *f,
 static ExitStatus help_goto_direct(DisasContext *s, uint64_t dest)
 {
     if (dest == s->next_pc) {
+        per_branch(s, true);
         return NO_EXIT;
     }
     if (use_goto_tb(s, dest)) {
@@ -1192,6 +1225,7 @@ static ExitStatus help_goto_direct(DisasContext *s, uint64_t dest)
         return EXIT_GOTO_TB;
     } else {
         tcg_gen_movi_i64(psw_addr, dest);
+        per_branch(s, false);
         return EXIT_PC_UPDATED;
     }
 }
@@ -1211,6 +1245,7 @@ static ExitStatus help_branch(DisasContext *s, DisasCompare *c,
     if (is_imm) {
         if (dest == s->next_pc) {
             /* Branch to next.  */
+            per_branch(s, true);
             ret = NO_EXIT;
             goto egress;
         }
@@ -1226,6 +1261,7 @@ static ExitStatus help_branch(DisasContext *s, DisasCompare *c,
         }
         if (c->cond == TCG_COND_ALWAYS) {
             tcg_gen_mov_i64(psw_addr, cdest);
+            per_branch(s, false);
             ret = EXIT_PC_UPDATED;
             goto egress;
         }
@@ -1296,6 +1332,7 @@ static ExitStatus help_branch(DisasContext *s, DisasCompare *c,
         if (c->is_64) {
             tcg_gen_movcond_i64(c->cond, psw_addr, c->u.s64.a, c->u.s64.b,
                                 cdest, next);
+            per_branch_cond(s, c->cond, c->u.s64.a, c->u.s64.b);
         } else {
             TCGv_i32 t0 = tcg_temp_new_i32();
             TCGv_i64 t1 = tcg_temp_new_i64();
@@ -1304,6 +1341,7 @@ static ExitStatus help_branch(DisasContext *s, DisasCompare *c,
             tcg_gen_extu_i32_i64(t1, t0);
             tcg_temp_free_i32(t0);
             tcg_gen_movcond_i64(TCG_COND_NE, psw_addr, t1, z, cdest, next);
+            per_branch_cond(s, TCG_COND_NE, t1, z);
             tcg_temp_free_i64(t1);
             tcg_temp_free_i64(z);
         }
@@ -1436,6 +1474,7 @@ static ExitStatus op_bas(DisasContext *s, DisasOps *o)
     tcg_gen_movi_i64(o->out, pc_to_link_info(s, s->next_pc));
     if (!TCGV_IS_UNUSED_I64(o->in2)) {
         tcg_gen_mov_i64(psw_addr, o->in2);
+        per_branch(s, false);
         return EXIT_PC_UPDATED;
     } else {
         return NO_EXIT;
-- 
2.1.4