[PULL 03/23] target/mips: add Octeon CRC COP2 helpers

["Philippe Mathieu-Daudé" <philmd@oss.qualcomm.com>]

From: James Hilliard <james.hilliard1@gmail.com>

Add helper support for the Octeon COP2 CRC register interface. This
covers normal and reflected CRC state handling, byte/halfword/word/
doubleword/variable-width update selectors, and the reflected IV readback
operation.

Register moves that can be represented as direct TCG loads/stores do not
need helpers. Add only the side-effecting CRC helper implementation here.

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20260608-mips-octeon-missing-insns-v2-v16-3-daef7a0d8b04@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
---
 target/mips/helper.h            |  14 ++++
 target/mips/tcg/octeon_crypto.c | 131 ++++++++++++++++++++++++++++++++
 2 files changed, 145 insertions(+)

diff --git a/target/mips/helper.h b/target/mips/helper.h
index e2b83a1d19d..e802f50fd6e 100644
--- a/target/mips/helper.h
+++ b/target/mips/helper.h
@@ -25,6 +25,20 @@ DEF_HELPER_3(crc32, tl, tl, tl, i32)
 DEF_HELPER_3(crc32c, tl, tl, tl, i32)
 DEF_HELPER_FLAGS_4(rotx, TCG_CALL_NO_RWG_SE, tl, tl, i32, i32, i32)
 
+/* Octeon COP2 selector operation helpers. */
+DEF_HELPER_1(octeon_cp2_mf_crc_iv_reflect, i64, env)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_iv_reflect, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_byte, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_half, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_word, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_byte_reflect, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_half_reflect, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_word_reflect, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_dword, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_var, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_dword_reflect, void, env, i64)
+DEF_HELPER_2(octeon_cp2_mt_crc_write_var_reflect, void, env, i64)
+
 /* microMIPS functions */
 DEF_HELPER_4(lwm, void, env, tl, tl, i32)
 DEF_HELPER_4(swm, void, env, tl, tl, i32)
diff --git a/target/mips/tcg/octeon_crypto.c b/target/mips/tcg/octeon_crypto.c
index df5b0449aeb..c589077ea7c 100644
--- a/target/mips/tcg/octeon_crypto.c
+++ b/target/mips/tcg/octeon_crypto.c
@@ -14,3 +14,134 @@
 #include "crypto/sm4.h"
 #include "qemu/bitops.h"
 #include "qemu/host-utils.h"
+
+static uint32_t octeon_crc_reflect32_by_byte(uint32_t v)
+{
+    return bswap32(revbit32(v));
+}
+
+static uint32_t octeon_crc_state_reflect(const MIPSOcteonCryptoState *crypto)
+{
+    return octeon_crc_reflect32_by_byte(crypto->crc_iv);
+}
+
+static void octeon_crc_set_state_reflect(MIPSOcteonCryptoState *crypto,
+                                         uint32_t state)
+{
+    crypto->crc_iv = octeon_crc_reflect32_by_byte(state);
+}
+
+static void octeon_crc_update_normal(MIPSOcteonCryptoState *crypto,
+                                     uint64_t value, unsigned int bytes)
+{
+    uint32_t crc = crypto->crc_iv;
+    uint32_t poly = crypto->crc_poly;
+
+    for (unsigned int i = 0; i < bytes; i++) {
+        uint8_t byte = value >> ((bytes - 1 - i) * 8);
+
+        crc ^= (uint32_t)byte << 24;
+        for (int bit = 0; bit < 8; bit++) {
+            if (crc & 0x80000000U) {
+                crc = (crc << 1) ^ poly;
+            } else {
+                crc <<= 1;
+            }
+        }
+    }
+
+    crypto->crc_iv = crc;
+}
+
+static void octeon_crc_update_reflect(MIPSOcteonCryptoState *crypto,
+                                      uint64_t value, unsigned int bytes)
+{
+    uint32_t crc = octeon_crc_state_reflect(crypto);
+    uint32_t poly = bswap32(crypto->crc_poly);
+
+    for (unsigned int i = 0; i < bytes; i++) {
+        uint8_t byte = value >> ((bytes - 1 - i) * 8);
+
+        crc ^= byte;
+        for (int bit = 0; bit < 8; bit++) {
+            if (crc & 1U) {
+                crc = (crc >> 1) ^ poly;
+            } else {
+                crc >>= 1;
+            }
+        }
+    }
+
+    octeon_crc_set_state_reflect(crypto, crc);
+}
+
+uint64_t helper_octeon_cp2_mf_crc_iv_reflect(CPUMIPSState *env)
+{
+    return octeon_crc_reflect32_by_byte(env->octeon_crypto.crc_iv);
+}
+
+void helper_octeon_cp2_mt_crc_write_iv_reflect(CPUMIPSState *env,
+                                               uint64_t value)
+{
+    env->octeon_crypto.crc_iv =
+        octeon_crc_reflect32_by_byte((uint32_t)value);
+}
+
+void helper_octeon_cp2_mt_crc_write_byte(CPUMIPSState *env, uint64_t value)
+{
+    octeon_crc_update_normal(&env->octeon_crypto, value, 1);
+}
+
+void helper_octeon_cp2_mt_crc_write_half(CPUMIPSState *env, uint64_t value)
+{
+    octeon_crc_update_normal(&env->octeon_crypto, value, 2);
+}
+
+void helper_octeon_cp2_mt_crc_write_word(CPUMIPSState *env, uint64_t value)
+{
+    octeon_crc_update_normal(&env->octeon_crypto, value, 4);
+}
+
+void helper_octeon_cp2_mt_crc_write_dword(CPUMIPSState *env, uint64_t value)
+{
+    octeon_crc_update_normal(&env->octeon_crypto, value, 8);
+}
+
+void helper_octeon_cp2_mt_crc_write_var(CPUMIPSState *env, uint64_t value)
+{
+    MIPSOcteonCryptoState *crypto = &env->octeon_crypto;
+
+    octeon_crc_update_normal(crypto, value, MIN(8U, crypto->crc_len & 0xf));
+}
+
+void helper_octeon_cp2_mt_crc_write_byte_reflect(CPUMIPSState *env,
+                                                 uint64_t value)
+{
+    octeon_crc_update_reflect(&env->octeon_crypto, value, 1);
+}
+
+void helper_octeon_cp2_mt_crc_write_half_reflect(CPUMIPSState *env,
+                                                 uint64_t value)
+{
+    octeon_crc_update_reflect(&env->octeon_crypto, value, 2);
+}
+
+void helper_octeon_cp2_mt_crc_write_word_reflect(CPUMIPSState *env,
+                                                 uint64_t value)
+{
+    octeon_crc_update_reflect(&env->octeon_crypto, value, 4);
+}
+
+void helper_octeon_cp2_mt_crc_write_dword_reflect(CPUMIPSState *env,
+                                                  uint64_t value)
+{
+    octeon_crc_update_reflect(&env->octeon_crypto, value, 8);
+}
+
+void helper_octeon_cp2_mt_crc_write_var_reflect(CPUMIPSState *env,
+                                                uint64_t value)
+{
+    MIPSOcteonCryptoState *crypto = &env->octeon_crypto;
+
+    octeon_crc_update_reflect(crypto, value, MIN(8U, crypto->crc_len & 0xf));
+}
-- 
2.53.0