Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
host/include/generic/host/crypto/clmul.h | 15 +++++++++++++++
include/crypto/clmul.h | 19 +++++++++++++++++++
crypto/clmul.c | 17 +++++++++++++++++
3 files changed, 51 insertions(+)
create mode 100644 host/include/generic/host/crypto/clmul.h
diff --git a/host/include/generic/host/crypto/clmul.h b/host/include/generic/host/crypto/clmul.h
new file mode 100644
index 0000000000..915bfb88d3
--- /dev/null
+++ b/host/include/generic/host/crypto/clmul.h
@@ -0,0 +1,15 @@
+/*
+ * No host specific carry-less multiply acceleration.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef GENERIC_HOST_CRYPTO_CLMUL_H
+#define GENERIC_HOST_CRYPTO_CLMUL_H
+
+#define HAVE_CLMUL_ACCEL false
+#define ATTR_CLMUL_ACCEL
+
+Int128 clmul_64_accel(uint64_t, uint64_t)
+ QEMU_ERROR("unsupported accel");
+
+#endif /* GENERIC_HOST_CRYPTO_CLMUL_H */
diff --git a/include/crypto/clmul.h b/include/crypto/clmul.h
index 80de516464..446931fe05 100644
--- a/include/crypto/clmul.h
+++ b/include/crypto/clmul.h
@@ -8,6 +8,9 @@
#ifndef CRYPTO_CLMUL_H
#define CRYPTO_CLMUL_H
+#include "qemu/int128.h"
+#include "host/crypto/clmul.h"
+
/**
* clmul_8x8_low:
*
@@ -61,4 +64,20 @@ uint64_t clmul_16x2_odd(uint64_t, uint64_t);
*/
uint64_t clmul_32(uint32_t, uint32_t);
+/**
+ * clmul_64:
+ *
+ * Perform a 64x64->128 carry-less multiply.
+ */
+Int128 clmul_64_gen(uint64_t, uint64_t);
+
+static inline Int128 clmul_64(uint64_t a, uint64_t b)
+{
+ if (HAVE_CLMUL_ACCEL) {
+ return clmul_64_accel(a, b);
+ } else {
+ return clmul_64_gen(a, b);
+ }
+}
+
#endif /* CRYPTO_CLMUL_H */
diff --git a/crypto/clmul.c b/crypto/clmul.c
index 36ada1be9d..9e3e61a77d 100644
--- a/crypto/clmul.c
+++ b/crypto/clmul.c
@@ -92,3 +92,20 @@ uint64_t clmul_32(uint32_t n, uint32_t m32)
}
return r;
}
+
+Int128 clmul_64_gen(uint64_t n, uint64_t m)
+{
+ uint64_t rl = 0, rh = 0;
+
+ /* Bit 0 can only influence the low 64-bit result. */
+ if (n & 1) {
+ rl = m;
+ }
+
+ for (int i = 1; i < 64; ++i) {
+ uint64_t mask = -((n >> i) & 1);
+ rl ^= (m << i) & mask;
+ rh ^= (m >> (64 - i)) & mask;
+ }
+ return int128_make128(rl, rh);
+}
--
2.34.1