[Qemu-devel] [PATCH v5 2/4] target/arm: implement SHA-3 instructions

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

This implements emulation of the new SHA-3 instructions that have
been added as an optional extensions to the ARMv8 Crypto Extensions
in ARM v8.2.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 target/arm/cpu.h           |   1 +
 target/arm/translate-a64.c | 148 +++++++++++++++++++-
 2 files changed, 145 insertions(+), 4 deletions(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 32a18510e70b..d0b19e0cbc88 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1373,6 +1373,7 @@ enum arm_features {
     ARM_FEATURE_JAZELLE, /* has (trivial) Jazelle implementation */
     ARM_FEATURE_SVE, /* has Scalable Vector Extension */
     ARM_FEATURE_V8_SHA512, /* implements SHA512 part of v8 Crypto Extensions */
+    ARM_FEATURE_V8_SHA3, /* implements SHA3 part of v8 Crypto Extensions */
 };
 
 static inline int arm_feature(CPUARMState *env, int feature)
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 888f5a39a283..10f2e518f303 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -11162,9 +11162,10 @@ static void disas_crypto_three_reg_sha512(DisasContext *s, uint32_t insn)
             feature = ARM_FEATURE_V8_SHA512;
             genfn = gen_helper_crypto_sha512su1;
             break;
-        default:
-            unallocated_encoding(s);
-            return;
+        case 3: /* RAX1 */
+            feature = ARM_FEATURE_V8_SHA3;
+            genfn = NULL;
+            break;
         }
     } else {
         unallocated_encoding(s);
@@ -11193,7 +11194,28 @@ static void disas_crypto_three_reg_sha512(DisasContext *s, uint32_t insn)
         tcg_temp_free_ptr(tcg_rn_ptr);
         tcg_temp_free_ptr(tcg_rm_ptr);
     } else {
-        g_assert_not_reached();
+        TCGv_i64 tcg_op1, tcg_op2, tcg_res[2];
+        int pass;
+
+        tcg_op1 = tcg_temp_new_i64();
+        tcg_op2 = tcg_temp_new_i64();
+        tcg_res[0] = tcg_temp_new_i64();
+        tcg_res[1] = tcg_temp_new_i64();
+
+        for (pass = 0; pass < 2; pass++) {
+            read_vec_element(s, tcg_op1, rn, pass, MO_64);
+            read_vec_element(s, tcg_op2, rm, pass, MO_64);
+
+            tcg_gen_rotli_i64(tcg_res[pass], tcg_op2, 1);
+            tcg_gen_xor_i64(tcg_res[pass], tcg_res[pass], tcg_op1);
+        }
+        write_vec_element(s, tcg_res[0], rd, 0, MO_64);
+        write_vec_element(s, tcg_res[1], rd, 1, MO_64);
+
+        tcg_temp_free(tcg_op1);
+        tcg_temp_free(tcg_op2);
+        tcg_temp_free(tcg_res[0]);
+        tcg_temp_free(tcg_res[1]);
     }
 }
 
@@ -11240,6 +11262,122 @@ static void disas_crypto_two_reg_sha512(DisasContext *s, uint32_t insn)
     tcg_temp_free_ptr(tcg_rn_ptr);
 }
 
+/* Crypto four-register
+ *  31               23 22 21 20  16 15  14  10 9    5 4    0
+ * +-------------------+-----+------+---+------+------+------+
+ * | 1 1 0 0 1 1 1 0 0 | Op0 |  Rm  | 0 |  Ra  |  Rn  |  Rd  |
+ * +-------------------+-----+------+---+------+------+------+
+ */
+static void disas_crypto_four_reg(DisasContext *s, uint32_t insn)
+{
+    int op0 = extract32(insn, 21, 2);
+    int rm = extract32(insn, 16, 5);
+    int ra = extract32(insn, 10, 5);
+    int rn = extract32(insn, 5, 5);
+    int rd = extract32(insn, 0, 5);
+    int feature;
+
+    switch (op0) {
+    case 0: /* EOR3 */
+    case 1: /* BCAX */
+        feature = ARM_FEATURE_V8_SHA3;
+        break;
+    default:
+        unallocated_encoding(s);
+        return;
+    }
+
+    if (!arm_dc_feature(s, feature)) {
+        unallocated_encoding(s);
+        return;
+    }
+
+    if (!fp_access_check(s)) {
+        return;
+    }
+
+    if (op0 < 2) {
+        TCG_i64 tcg_op1, tcg_op2, tcg_op3, tcg_res[2];
+        int pass;
+
+        tcg_op1 = tcg_temp_new_i64();
+        tcg_op2 = tcg_temp_new_i64();
+        tcg_op3 = tcg_temp_new_i64();
+        tcg_res[0] = tcg_temp_new_i64();
+        tcg_res[1] = tcg_temp_new_i64();
+
+        for (pass = 0; pass < 2; pass++) {
+            read_vec_element(s, tcg_op1, rn, pass, MO_64);
+            read_vec_element(s, tcg_op2, rm, pass, MO_64);
+            read_vec_element(s, tcg_op3, ra, pass, MO_64);
+
+            if (op0 == 0) {
+                /* EOR3 */
+                tcg_gen_xor_i64(tcg_res[pass], tcg_op2, tcg_op3);
+            } else {
+                /* BCAX */
+                tcg_gen_andc_i64(tcg_res[pass], tcg_op2, tcg_op3);
+            }
+            tcg_gen_xor_i64(tcg_res[pass], tcg_res[pass], tcg_op1);
+        }
+        write_vec_element(s, tcg_res[0], rd, 0, MO_64);
+        write_vec_element(s, tcg_res[1], rd, 1, MO_64);
+
+        tcg_temp_free(tcg_op1);
+        tcg_temp_free(tcg_op2);
+        tcg_temp_free(tcg_op3);
+        tcg_temp_free(tcg_res[0]);
+        tcg_temp_free(tcg_res[1]);
+    } else {
+        g_assert_not_reached();
+    }
+}
+
+/* Crypto XAR
+ *  31                   21 20  16 15    10 9    5 4    0
+ * +-----------------------+------+--------+------+------+
+ * | 1 1 0 0 1 1 1 0 1 0 0 |  Rm  |  imm6  |  Rn  |  Rd  |
+ * +-----------------------+------+--------+------+------+
+ */
+static void disas_crypto_xar(DisasContext *s, uint32_t insn)
+{
+    int rm = extract32(insn, 16, 5);
+    int imm6 = extract32(insn, 10, 6);
+    int rn = extract32(insn, 5, 5);
+    int rd = extract32(insn, 0, 5);
+    TCGv_i64 tcg_op1, tcg_op2, tcg_res[2];
+    int pass;
+
+    if (!arm_dc_feature(s, ARM_FEATURE_V8_SHA3)) {
+        unallocated_encoding(s);
+        return;
+    }
+
+    if (!fp_access_check(s)) {
+        return;
+    }
+
+    tcg_op1 = tcg_temp_new_i64();
+    tcg_op2 = tcg_temp_new_i64();
+    tcg_res[0] = tcg_temp_new_i64();
+    tcg_res[1] = tcg_temp_new_i64();
+
+    for (pass = 0; pass < 2; pass++) {
+        read_vec_element(s, tcg_op1, rn, pass, MO_64);
+        read_vec_element(s, tcg_op2, rm, pass, MO_64);
+
+        tcg_gen_xor_i64(tcg_res[pass], tcg_op1, tcg_op2);
+        tcg_gen_rotri_i64(tcg_res[pass], tcg_res[pass], imm6);
+    }
+    write_vec_element(s, tcg_res[0], rd, 0, MO_64);
+    write_vec_element(s, tcg_res[1], rd, 1, MO_64);
+
+    tcg_temp_free(tcg_op1);
+    tcg_temp_free(tcg_op2);
+    tcg_temp_free(tcg_res[0]);
+    tcg_temp_free(tcg_res[1]);
+}
+
 /* C3.6 Data processing - SIMD, inc Crypto
  *
  * As the decode gets a little complex we are using a table based
@@ -11271,6 +11409,8 @@ static const AArch64DecodeTable data_proc_simd[] = {
     { 0x5e280800, 0xff3e0c00, disas_crypto_two_reg_sha },
     { 0xce608000, 0xffe0b000, disas_crypto_three_reg_sha512 },
     { 0xcec08000, 0xfffff000, disas_crypto_two_reg_sha512 },
+    { 0xce000000, 0xff808000, disas_crypto_four_reg },
+    { 0xce800000, 0xffe00000, disas_crypto_xar },
     { 0x00000000, 0x00000000, NULL }
 };
 
-- 
2.11.0