[Qemu-devel] [PULL 15/33] s390x/tcg: Implement VECTOR LOAD TO BLOCK BOUNDARY

[Cornelia Huck]

From: David Hildenbrand <address@hidden>

Very similar to LOAD COUNT TO BLOCK BOUNDARY, but instead of only
calculating, the actual vector is loaded. Use a temporary vector to
not modify the real vector on exceptions. Initialize that one to zero,
to not leak any data. Provide a fast path if we're loading a full
vector.

As we don't have gvec ool handlers for single vectors, just calculate
the vector address manually.

We can reuse the helper later on for VECTOR LOAD WITH LENGTH. In fact,
we are going to name it "vll" right from the beginning, because that's
a better match.

Reviewed-by: Richard Henderson <address@hidden>
Signed-off-by: David Hildenbrand <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Cornelia Huck <address@hidden>
---
 target/s390x/Makefile.objs      |  1 +
 target/s390x/helper.h           |  3 +++
 target/s390x/insn-data.def      |  2 ++
 target/s390x/translate_vx.inc.c | 25 +++++++++++++++++++
 target/s390x/vec_helper.c       | 44 +++++++++++++++++++++++++++++++++
 5 files changed, 75 insertions(+)
 create mode 100644 target/s390x/vec_helper.c

diff --git a/target/s390x/Makefile.objs b/target/s390x/Makefile.objs
index 22a9a9927acb..68eeee3d2f9b 100644
--- a/target/s390x/Makefile.objs
+++ b/target/s390x/Makefile.objs
@@ -1,6 +1,7 @@
 obj-y += cpu.o cpu_models.o cpu_features.o gdbstub.o interrupt.o helper.o
 obj-$(CONFIG_TCG) += translate.o cc_helper.o excp_helper.o fpu_helper.o
 obj-$(CONFIG_TCG) += int_helper.o mem_helper.o misc_helper.o crypto_helper.o
+obj-$(CONFIG_TCG) += vec_helper.o
 obj-$(CONFIG_SOFTMMU) += machine.o ioinst.o arch_dump.o mmu_helper.o diag.o
 obj-$(CONFIG_SOFTMMU) += sigp.o
 obj-$(CONFIG_KVM) += kvm.o
diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index bb659257f6cd..6c745ba0f6ad 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -124,6 +124,9 @@ DEF_HELPER_5(msa, i32, env, i32, i32, i32, i32)
 DEF_HELPER_FLAGS_1(stpt, TCG_CALL_NO_RWG, i64, env)
 DEF_HELPER_FLAGS_1(stck, TCG_CALL_NO_RWG_SE, i64, env)
 
+/* === Vector Support Instructions === */
+DEF_HELPER_FLAGS_4(vll, TCG_CALL_NO_WG, void, env, ptr, i64, i64)
+
 #ifndef CONFIG_USER_ONLY
 DEF_HELPER_3(servc, i32, env, i64, i64)
 DEF_HELPER_4(diag, void, env, i32, i32, i32)
diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index fa0f3a90034d..ad8df5283cfd 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -1002,6 +1002,8 @@
     F(0xe704, VLLEZ,   VRX,   V,   la2, 0, 0, 0, vllez, 0, IF_VEC)
 /* VECTOR LOAD MULTIPLE */
     F(0xe736, VLM,     VRS_a, V,   la2, 0, 0, 0, vlm, 0, IF_VEC)
+/* VECTOR LOAD TO BLOCK BOUNDARY */
+    F(0xe707, VLBB,    VRX,   V,   la2, 0, 0, 0, vlbb, 0, IF_VEC)
 
 #ifndef CONFIG_USER_ONLY
 /* COMPARE AND SWAP AND PURGE */
diff --git a/target/s390x/translate_vx.inc.c b/target/s390x/translate_vx.inc.c
index 083f5c621334..f1eb45890201 100644
--- a/target/s390x/translate_vx.inc.c
+++ b/target/s390x/translate_vx.inc.c
@@ -446,3 +446,28 @@ static DisasJumpType op_vlm(DisasContext *s, DisasOps *o)
     tcg_temp_free_i64(t1);
     return DISAS_NEXT;
 }
+
+static DisasJumpType op_vlbb(DisasContext *s, DisasOps *o)
+{
+    const int64_t block_size = (1ull << (get_field(s->fields, m3) + 6));
+    const int v1_offs = vec_full_reg_offset(get_field(s->fields, v1));
+    TCGv_ptr a0;
+    TCGv_i64 bytes;
+
+    if (get_field(s->fields, m3) > 6) {
+        gen_program_exception(s, PGM_SPECIFICATION);
+        return DISAS_NORETURN;
+    }
+
+    bytes = tcg_temp_new_i64();
+    a0 = tcg_temp_new_ptr();
+    /* calculate the number of bytes until the next block boundary */
+    tcg_gen_ori_i64(bytes, o->addr1, -block_size);
+    tcg_gen_neg_i64(bytes, bytes);
+
+    tcg_gen_addi_ptr(a0, cpu_env, v1_offs);
+    gen_helper_vll(cpu_env, a0, o->addr1, bytes);
+    tcg_temp_free_i64(bytes);
+    tcg_temp_free_ptr(a0);
+    return DISAS_NEXT;
+}
diff --git a/target/s390x/vec_helper.c b/target/s390x/vec_helper.c
new file mode 100644
index 000000000000..5b2333a8d666
--- /dev/null
+++ b/target/s390x/vec_helper.c
@@ -0,0 +1,44 @@
+/*
+ * QEMU TCG support -- s390x vector support instructions
+ *
+ * Copyright (C) 2019 Red Hat Inc
+ *
+ * Authors:
+ *   David Hildenbrand <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "cpu.h"
+#include "internal.h"
+#include "vec.h"
+#include "tcg/tcg.h"
+#include "exec/helper-proto.h"
+#include "exec/cpu_ldst.h"
+#include "exec/exec-all.h"
+
+void HELPER(vll)(CPUS390XState *env, void *v1, uint64_t addr, uint64_t bytes)
+{
+    if (likely(bytes >= 16)) {
+        uint64_t t0, t1;
+
+        t0 = cpu_ldq_data_ra(env, addr, GETPC());
+        addr = wrap_address(env, addr + 8);
+        t1 = cpu_ldq_data_ra(env, addr, GETPC());
+        s390_vec_write_element64(v1, 0, t0);
+        s390_vec_write_element64(v1, 1, t1);
+    } else {
+        S390Vector tmp = {};
+        int i;
+
+        for (i = 0; i < bytes; i++) {
+            uint8_t byte = cpu_ldub_data_ra(env, addr, GETPC());
+
+            s390_vec_write_element8(&tmp, i, byte);
+            addr = wrap_address(env, addr + 1);
+        }
+        *(S390Vector *)v1 = tmp;
+    }
+}
-- 
2.17.2