[PATCH v4 10/17] target/ppc: Create helper_scv

[Richard Henderson]

Perform the test against FSCR_SCV at runtime, in the helper.

This means we can remove the incorrect set against SCV in
ppc_tr_init_disas_context and do not need to add an HFLAGS bit.

Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
 target/ppc/helper.h      |  1 +
 target/ppc/excp_helper.c |  9 +++++++++
 target/ppc/translate.c   | 20 +++++++-------------
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 6a4dccf70c..513066d54d 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -13,6 +13,7 @@ DEF_HELPER_1(rfci, void, env)
 DEF_HELPER_1(rfdi, void, env)
 DEF_HELPER_1(rfmci, void, env)
 #if defined(TARGET_PPC64)
+DEF_HELPER_2(scv, noreturn, env, i32)
 DEF_HELPER_2(pminsn, void, env, i32)
 DEF_HELPER_1(rfid, void, env)
 DEF_HELPER_1(rfscv, void, env)
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index 85de7e6c90..5c95e0c103 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -1130,6 +1130,15 @@ void helper_store_msr(CPUPPCState *env, target_ulong val)
 }
 
 #if defined(TARGET_PPC64)
+void helper_scv(CPUPPCState *env, uint32_t lev)
+{
+    if (env->spr[SPR_FSCR] & (1ull << FSCR_SCV)) {
+        raise_exception_err(env, POWERPC_EXCP_SYSCALL_VECTORED, lev);
+    } else {
+        raise_exception_err(env, POWERPC_EXCP_FU, FSCR_IC_SCV);
+    }
+}
+
 void helper_pminsn(CPUPPCState *env, powerpc_pm_insn_t insn)
 {
     CPUState *cs;
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 7912495f28..d48c554290 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -173,7 +173,6 @@ struct DisasContext {
     bool vsx_enabled;
     bool spe_enabled;
     bool tm_enabled;
-    bool scv_enabled;
     bool gtse;
     ppc_spr_t *spr_cb; /* Needed to check rights for mfspr/mtspr */
     int singlestep_enabled;
@@ -4081,15 +4080,16 @@ static void gen_sc(DisasContext *ctx)
 #if !defined(CONFIG_USER_ONLY)
 static void gen_scv(DisasContext *ctx)
 {
-    uint32_t lev;
+    uint32_t lev = (ctx->opcode >> 5) & 0x7F;
 
-    if (unlikely(!ctx->scv_enabled)) {
-        gen_exception_err(ctx, POWERPC_EXCP_FU, FSCR_IC_SCV);
-        return;
+    /* Set the PC back to the faulting instruction. */
+    if (ctx->exception == POWERPC_EXCP_NONE) {
+        gen_update_nip(ctx, ctx->base.pc_next - 4);
     }
+    gen_helper_scv(cpu_env, tcg_constant_i32(lev));
 
-    lev = (ctx->opcode >> 5) & 0x7F;
-    gen_exception_err(ctx, POWERPC_SYSCALL_VECTORED, lev);
+    /* This need not be exact, just not POWERPC_EXCP_NONE */
+    ctx->exception = POWERPC_SYSCALL_VECTORED;
 }
 #endif
 #endif
@@ -7907,12 +7907,6 @@ static void ppc_tr_init_disas_context(DisasContextBase 
*dcbase, CPUState *cs)
     ctx->spe_enabled = (hflags >> HFLAGS_SPE) & 1;
     ctx->altivec_enabled = (hflags >> HFLAGS_VR) & 1;
     ctx->vsx_enabled = (hflags >> HFLAGS_VSX) & 1;
-    if ((env->flags & POWERPC_FLAG_SCV)
-        && (env->spr[SPR_FSCR] & (1ull << FSCR_SCV))) {
-        ctx->scv_enabled = true;
-    } else {
-        ctx->scv_enabled = false;
-    }
     ctx->tm_enabled = (hflags >> HFLAGS_TM) & 1;
     ctx->gtse = !!(env->spr[SPR_LPCR] & LPCR_GTSE);
 
-- 
2.25.1