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-rw-r--r--lib/zinc/poly1305/poly1305-arm-glue.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/lib/zinc/poly1305/poly1305-arm-glue.c b/lib/zinc/poly1305/poly1305-arm-glue.c
new file mode 100644
index 000000000000..a80f0460ea13
--- /dev/null
+++ b/lib/zinc/poly1305/poly1305-arm-glue.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include <asm/hwcap.h>
+#include <asm/neon.h>
+
+asmlinkage void poly1305_init_arm(void *ctx, const u8 key[16]);
+asmlinkage void poly1305_blocks_arm(void *ctx, const u8 *inp, const size_t len,
+ const u32 padbit);
+asmlinkage void poly1305_emit_arm(void *ctx, u8 mac[16], const u32 nonce[4]);
+asmlinkage void poly1305_blocks_neon(void *ctx, const u8 *inp, const size_t len,
+ const u32 padbit);
+asmlinkage void poly1305_emit_neon(void *ctx, u8 mac[16], const u32 nonce[4]);
+
+static bool poly1305_use_neon __ro_after_init;
+static bool *const poly1305_nobs[] __initconst = { &poly1305_use_neon };
+
+static void __init poly1305_fpu_init(void)
+{
+#if defined(CONFIG_ZINC_ARCH_ARM64)
+ poly1305_use_neon = elf_hwcap & HWCAP_ASIMD;
+#elif defined(CONFIG_ZINC_ARCH_ARM)
+ poly1305_use_neon = elf_hwcap & HWCAP_NEON;
+#endif
+}
+
+#if defined(CONFIG_ZINC_ARCH_ARM64)
+struct poly1305_arch_internal {
+ union {
+ u32 h[5];
+ struct {
+ u64 h0, h1, h2;
+ };
+ };
+ u64 is_base2_26;
+ u64 r[2];
+};
+#elif defined(CONFIG_ZINC_ARCH_ARM)
+struct poly1305_arch_internal {
+ union {
+ u32 h[5];
+ struct {
+ u64 h0, h1;
+ u32 h2;
+ } __packed;
+ };
+ u32 r[4];
+ u32 is_base2_26;
+};
+#endif
+
+/* The NEON code uses base 2^26, while the scalar code uses base 2^64 on 64-bit
+ * and base 2^32 on 32-bit. If we hit the unfortunate situation of using NEON
+ * and then having to go back to scalar -- because the user is silly and has
+ * called the update function from two separate contexts -- then we need to
+ * convert back to the original base before proceeding. The below function is
+ * written for 64-bit integers, and so we have to swap words at the end on
+ * big-endian 32-bit. It is possible to reason that the initial reduction below
+ * is sufficient given the implementation invariants. However, for an avoidance
+ * of doubt and because this is not performance critical, we do the full
+ * reduction anyway.
+ */
+static void convert_to_base2_64(void *ctx)
+{
+ struct poly1305_arch_internal *state = ctx;
+ u32 cy;
+
+ if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !state->is_base2_26)
+ return;
+
+ cy = state->h[0] >> 26; state->h[0] &= 0x3ffffff; state->h[1] += cy;
+ cy = state->h[1] >> 26; state->h[1] &= 0x3ffffff; state->h[2] += cy;
+ cy = state->h[2] >> 26; state->h[2] &= 0x3ffffff; state->h[3] += cy;
+ cy = state->h[3] >> 26; state->h[3] &= 0x3ffffff; state->h[4] += cy;
+ state->h0 = ((u64)state->h[2] << 52) | ((u64)state->h[1] << 26) | state->h[0];
+ state->h1 = ((u64)state->h[4] << 40) | ((u64)state->h[3] << 14) | (state->h[2] >> 12);
+ state->h2 = state->h[4] >> 24;
+ if (IS_ENABLED(CONFIG_ZINC_ARCH_ARM) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
+ state->h0 = rol64(state->h0, 32);
+ state->h1 = rol64(state->h1, 32);
+ }
+#define ULT(a, b) ((a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1))
+ cy = (state->h2 >> 2) + (state->h2 & ~3ULL);
+ state->h2 &= 3;
+ state->h0 += cy;
+ state->h1 += (cy = ULT(state->h0, cy));
+ state->h2 += ULT(state->h1, cy);
+#undef ULT
+ state->is_base2_26 = 0;
+}
+
+static inline bool poly1305_init_arch(void *ctx,
+ const u8 key[POLY1305_KEY_SIZE])
+{
+ poly1305_init_arm(ctx, key);
+ return true;
+}
+
+static inline bool poly1305_blocks_arch(void *ctx, const u8 *inp,
+ size_t len, const u32 padbit,
+ simd_context_t *simd_context)
+{
+ /* SIMD disables preemption, so relax after processing each page. */
+ BUILD_BUG_ON(PAGE_SIZE < POLY1305_BLOCK_SIZE ||
+ PAGE_SIZE % POLY1305_BLOCK_SIZE);
+
+ if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !poly1305_use_neon ||
+ !simd_use(simd_context)) {
+ convert_to_base2_64(ctx);
+ poly1305_blocks_arm(ctx, inp, len, padbit);
+ return true;
+ }
+
+ for (;;) {
+ const size_t bytes = min_t(size_t, len, PAGE_SIZE);
+
+ poly1305_blocks_neon(ctx, inp, bytes, padbit);
+ len -= bytes;
+ if (!len)
+ break;
+ inp += bytes;
+ simd_relax(simd_context);
+ }
+ return true;
+}
+
+static inline bool poly1305_emit_arch(void *ctx, u8 mac[POLY1305_MAC_SIZE],
+ const u32 nonce[4],
+ simd_context_t *simd_context)
+{
+ if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !poly1305_use_neon ||
+ !simd_use(simd_context)) {
+ convert_to_base2_64(ctx);
+ poly1305_emit_arm(ctx, mac, nonce);
+ } else
+ poly1305_emit_neon(ctx, mac, nonce);
+ return true;
+}