[Qemu-devel] [PATCH 3/3] target-arm: Add support for AArch32 ARMv8 CRC32 instructions

[Will Newton <will.newton@linaro.org>]

Add support for AArch32 CRC32 and CRC32C instructions added in ARMv8.

Signed-off-by: Will Newton <will.newton@linaro.org>
---
 target-arm/helper.c    | 37 +++++++++++++++++++++++++++++++++++++
 target-arm/helper.h    |  3 +++
 target-arm/translate.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+)

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 5ae08c9..d773612 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -5,6 +5,8 @@
 #include "sysemu/arch_init.h"
 #include "sysemu/sysemu.h"
 #include "qemu/bitops.h"
+#include "qemu/crc32.h"
+#include "qemu/crc32c.h"
 
 #ifndef CONFIG_USER_ONLY
 static inline int get_phys_addr(CPUARMState *env, uint32_t address,
@@ -4468,3 +4470,38 @@ int arm_rmode_to_sf(int rmode)
     }
     return rmode;
 }
+
+static void crc_init_buffer(uint8_t *buf, uint32_t val, uint32_t bytes)
+{
+    memset(buf, 0, 4);
+
+    if (bytes == 1) {
+        buf[0] = val & 0xff;
+    } else if (bytes == 2) {
+        buf[0] = val & 0xff;
+        buf[1] = (val >> 8) & 0xff;
+    } else {
+        buf[0] = val & 0xff;
+        buf[1] = (val >> 8) & 0xff;
+        buf[2] = (val >> 16) & 0xff;
+        buf[3] = (val >> 24) & 0xff;
+    }
+}
+
+uint32_t HELPER(crc32)(uint32_t acc, uint32_t val, uint32_t bytes)
+{
+    uint8_t buf[4];
+
+    crc_init_buffer(buf, val, bytes);
+
+    return crc32(acc, buf, bytes) ^ 0xffffffff;
+}
+
+uint32_t HELPER(crc32c)(uint32_t acc, uint32_t val, uint32_t bytes)
+{
+    uint8_t buf[4];
+
+    crc_init_buffer(buf, val, bytes);
+
+    return crc32c(acc, buf, bytes) ^ 0xffffffff;
+}
diff --git a/target-arm/helper.h b/target-arm/helper.h
index 951e6ad..fb92e53 100644
--- a/target-arm/helper.h
+++ b/target-arm/helper.h
@@ -494,6 +494,9 @@ DEF_HELPER_3(neon_qzip32, void, env, i32, i32)
 DEF_HELPER_4(crypto_aese, void, env, i32, i32, i32)
 DEF_HELPER_4(crypto_aesmc, void, env, i32, i32, i32)
 
+DEF_HELPER_3(crc32, i32, i32, i32, i32)
+DEF_HELPER_3(crc32c, i32, i32, i32, i32)
+
 #ifdef TARGET_AARCH64
 #include "helper-a64.h"
 #endif
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 782aab8..9410b6a 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -7541,6 +7541,32 @@ static void disas_arm_insn(CPUARMState * env, DisasContext *s)
             store_reg(s, 14, tmp2);
             gen_bx(s, tmp);
             break;
+        case 0x4:
+        {
+            /* crc32/crc32c */
+            uint32_t c = extract32(insn, 9, 1);
+
+            /* size == 64 is UNPREDICTABLE but handle as UNDEFINED.  */
+            if (op1 == 0x3) {
+                goto illegal_op;
+            }
+
+            rn = (insn >> 16) & 0xf;
+            rd = (insn >> 12) & 0xf;
+
+            tmp = load_reg(s, rn);
+            tmp2 = load_reg(s, rm);
+            tmp3 = tcg_const_i32(1 << op1);
+            if (c) {
+                gen_helper_crc32c(tmp, tmp, tmp2, tmp3);
+            } else {
+                gen_helper_crc32(tmp, tmp, tmp2, tmp3);
+            }
+            tcg_temp_free_i32(tmp2);
+            tcg_temp_free_i32(tmp3);
+            store_reg(s, rd, tmp);
+            break;
+        }
         case 0x5: /* saturating add/subtract */
             ARCH(5TE);
             rd = (insn >> 12) & 0xf;
@@ -9125,6 +9151,28 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw
                 case 0x18: /* clz */
                     gen_helper_clz(tmp, tmp);
                     break;
+                case 0x20:
+                case 0x21:
+                case 0x22:
+                case 0x28:
+                case 0x29:
+                case 0x2a:
+                {
+                    /* crc32/crc32c */
+                    uint32_t sz = op & 0x3;
+                    uint32_t c = op & 0x8;
+
+                    tmp2 = load_reg(s, rm);
+                    tmp3 = tcg_const_i32(1 << sz);
+                    if (c) {
+                        gen_helper_crc32c(tmp, tmp, tmp2, tmp3);
+                    } else {
+                        gen_helper_crc32(tmp, tmp, tmp2, tmp3);
+                    }
+                    tcg_temp_free_i32(tmp2);
+                    tcg_temp_free_i32(tmp3);
+                    break;
+                }
                 default:
                     goto illegal_op;
                 }
-- 
1.8.1.4