Re: [PATCH v2 07/13] target/ppc: Split out helper_dbczl for 970

[BALATON Zoltan]

On Tue, 9 Jul 2024, Richard Henderson wrote:

We can determine at translation time whether the insn is or
is not dbczl.  We must retain a runtime check against the
HID5 register, but we can move that to a separate function
that never affects other ppc models.

Signed-off-by: Richard Henderson <richard.hender...@linaro.org>

Reviewed-by: BALATON Zoltan <bala...@eik.bme.hu>

Regards,
BALATON Zoltan

---
target/ppc/helper.h     |  7 +++++--
target/ppc/mem_helper.c | 34 +++++++++++++++++++++-------------
target/ppc/translate.c  | 24 ++++++++++++++----------
3 files changed, 40 insertions(+), 25 deletions(-)

diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 76b8f25c77..afc56855ff 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -46,8 +46,11 @@ DEF_HELPER_FLAGS_3(stmw, TCG_CALL_NO_WG, void, env, tl, i32)
DEF_HELPER_4(lsw, void, env, tl, i32, i32)
DEF_HELPER_5(lswx, void, env, tl, i32, i32, i32)
DEF_HELPER_FLAGS_4(stsw, TCG_CALL_NO_WG, void, env, tl, i32, i32)
-DEF_HELPER_FLAGS_3(dcbz, TCG_CALL_NO_WG, void, env, tl, i32)
-DEF_HELPER_FLAGS_3(dcbzep, TCG_CALL_NO_WG, void, env, tl, i32)
+DEF_HELPER_FLAGS_2(dcbz, TCG_CALL_NO_WG, void, env, tl)
+DEF_HELPER_FLAGS_2(dcbzep, TCG_CALL_NO_WG, void, env, tl)
+#ifdef TARGET_PPC64
+DEF_HELPER_FLAGS_2(dcbzl, TCG_CALL_NO_WG, void, env, tl)
+#endif
DEF_HELPER_FLAGS_2(icbi, TCG_CALL_NO_WG, void, env, tl)
DEF_HELPER_FLAGS_2(icbiep, TCG_CALL_NO_WG, void, env, tl)
DEF_HELPER_5(lscbx, tl, env, tl, i32, i32, i32)
diff --git a/target/ppc/mem_helper.c b/target/ppc/mem_helper.c
index 5067919ff8..d4957efd6e 100644
--- a/target/ppc/mem_helper.c
+++ b/target/ppc/mem_helper.c
@@ -296,26 +296,34 @@ static void dcbz_common(CPUPPCState *env, target_ulong 
addr,
    }
}

-void helper_dcbz(CPUPPCState *env, target_ulong addr, uint32_t opcode)
+void helper_dcbz(CPUPPCState *env, target_ulong addr)
{
-    int dcbz_size = env->dcache_line_size;
-
-#if defined(TARGET_PPC64)
-    /* Check for dcbz vs dcbzl on 970 */
-    if (env->excp_model == POWERPC_EXCP_970 &&
-        !(opcode & 0x00200000) && ((env->spr[SPR_970_HID5] >> 7) & 0x3) == 1) {
-        dcbz_size = 32;
-    }
-#endif
-
-    dcbz_common(env, addr, dcbz_size, ppc_env_mmu_index(env, false), GETPC());
+    dcbz_common(env, addr, env->dcache_line_size,
+                ppc_env_mmu_index(env, false), GETPC());
}

-void helper_dcbzep(CPUPPCState *env, target_ulong addr, uint32_t opcode)
+void helper_dcbzep(CPUPPCState *env, target_ulong addr)
{
    dcbz_common(env, addr, env->dcache_line_size, PPC_TLB_EPID_STORE, GETPC());
}

+#ifdef TARGET_PPC64
+void helper_dcbzl(CPUPPCState *env, target_ulong addr)
+{
+    int dcbz_size = env->dcache_line_size;
+
+    /*
+     * The translator checked for POWERPC_EXCP_970.
+     * All that's left is to check HID5.
+     */
+    if (((env->spr[SPR_970_HID5] >> 7) & 0x3) == 1) {
+        dcbz_size = 32;
+    }
+
+    dcbz_common(env, addr, dcbz_size, ppc_env_mmu_index(env, false), GETPC());
+}
+#endif
+
void helper_icbi(CPUPPCState *env, target_ulong addr)
{
    addr &= ~(env->dcache_line_size - 1);
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 0bc16d7251..2664c94522 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -200,6 +200,7 @@ struct DisasContext {
    uint32_t flags;
    uint64_t insns_flags;
    uint64_t insns_flags2;
+    powerpc_excp_t excp_model;
};

#define DISAS_EXIT         DISAS_TARGET_0  /* exit to main loop, pc updated */
@@ -4445,27 +4446,29 @@ static void gen_dcblc(DisasContext *ctx)
/* dcbz */
static void gen_dcbz(DisasContext *ctx)
{
-    TCGv tcgv_addr;
-    TCGv_i32 tcgv_op;
+    TCGv tcgv_addr = tcg_temp_new();

    gen_set_access_type(ctx, ACCESS_CACHE);
-    tcgv_addr = tcg_temp_new();
-    tcgv_op = tcg_constant_i32(ctx->opcode & 0x03FF000);
    gen_addr_reg_index(ctx, tcgv_addr);
-    gen_helper_dcbz(tcg_env, tcgv_addr, tcgv_op);
+
+#ifdef TARGET_PPC64
+    if (ctx->excp_model == POWERPC_EXCP_970 && !(ctx->opcode & 0x00200000)) {
+        gen_helper_dcbzl(tcg_env, tcgv_addr);
+        return;
+    }
+#endif
+
+    gen_helper_dcbz(tcg_env, tcgv_addr);
}

/* dcbzep */
static void gen_dcbzep(DisasContext *ctx)
{
-    TCGv tcgv_addr;
-    TCGv_i32 tcgv_op;
+    TCGv tcgv_addr = tcg_temp_new();

    gen_set_access_type(ctx, ACCESS_CACHE);
-    tcgv_addr = tcg_temp_new();
-    tcgv_op = tcg_constant_i32(ctx->opcode & 0x03FF000);
    gen_addr_reg_index(ctx, tcgv_addr);
-    gen_helper_dcbzep(tcg_env, tcgv_addr, tcgv_op);
+    gen_helper_dcbzep(tcg_env, tcgv_addr);
}

/* dst / dstt */
@@ -6480,6 +6483,7 @@ static void ppc_tr_init_disas_context(DisasContextBase 
*dcbase, CPUState *cs)
    ctx->hv = (hflags >> HFLAGS_HV) & 1;
    ctx->insns_flags = env->insns_flags;
    ctx->insns_flags2 = env->insns_flags2;
+    ctx->excp_model = env->excp_model;
    ctx->access_type = -1;
    ctx->need_access_type = !mmu_is_64bit(env->mmu_model);
    ctx->le_mode = (hflags >> HFLAGS_LE) & 1;