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-rw-r--r--arch/arm/crypto/chacha-glue.c343
1 files changed, 343 insertions, 0 deletions
diff --git a/arch/arm/crypto/chacha-glue.c b/arch/arm/crypto/chacha-glue.c
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index 000000000000..3f0c057aa050
--- /dev/null
+++ b/arch/arm/crypto/chacha-glue.c
@@ -0,0 +1,343 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM NEON accelerated ChaCha and XChaCha stream ciphers,
+ * including ChaCha20 (RFC7539)
+ *
+ * Copyright (C) 2016-2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
+ * Copyright (C) 2015 Martin Willi
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/internal/chacha.h>
+#include <crypto/internal/simd.h>
+#include <crypto/internal/skcipher.h>
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <asm/cputype.h>
+#include <asm/hwcap.h>
+#include <asm/neon.h>
+#include <asm/simd.h>
+
+asmlinkage void chacha_block_xor_neon(const u32 *state, u8 *dst, const u8 *src,
+ int nrounds);
+asmlinkage void chacha_4block_xor_neon(const u32 *state, u8 *dst, const u8 *src,
+ int nrounds);
+asmlinkage void hchacha_block_arm(const u32 *state, u32 *out, int nrounds);
+asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds);
+
+asmlinkage void chacha_doarm(u8 *dst, const u8 *src, unsigned int bytes,
+ const u32 *state, int nrounds);
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(use_neon);
+
+static inline bool neon_usable(void)
+{
+ return static_branch_likely(&use_neon) && crypto_simd_usable();
+}
+
+static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds)
+{
+ u8 buf[CHACHA_BLOCK_SIZE];
+
+ while (bytes >= CHACHA_BLOCK_SIZE * 4) {
+ chacha_4block_xor_neon(state, dst, src, nrounds);
+ bytes -= CHACHA_BLOCK_SIZE * 4;
+ src += CHACHA_BLOCK_SIZE * 4;
+ dst += CHACHA_BLOCK_SIZE * 4;
+ state[12] += 4;
+ }
+ while (bytes >= CHACHA_BLOCK_SIZE) {
+ chacha_block_xor_neon(state, dst, src, nrounds);
+ bytes -= CHACHA_BLOCK_SIZE;
+ src += CHACHA_BLOCK_SIZE;
+ dst += CHACHA_BLOCK_SIZE;
+ state[12]++;
+ }
+ if (bytes) {
+ memcpy(buf, src, bytes);
+ chacha_block_xor_neon(state, buf, buf, nrounds);
+ memcpy(dst, buf, bytes);
+ }
+}
+
+void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
+{
+ if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable()) {
+ hchacha_block_arm(state, stream, nrounds);
+ } else {
+ kernel_neon_begin();
+ hchacha_block_neon(state, stream, nrounds);
+ kernel_neon_end();
+ }
+}
+EXPORT_SYMBOL(hchacha_block_arch);
+
+void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv)
+{
+ chacha_init_generic(state, key, iv);
+}
+EXPORT_SYMBOL(chacha_init_arch);
+
+void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes,
+ int nrounds)
+{
+ if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable() ||
+ bytes <= CHACHA_BLOCK_SIZE) {
+ chacha_doarm(dst, src, bytes, state, nrounds);
+ state[12] += DIV_ROUND_UP(bytes, CHACHA_BLOCK_SIZE);
+ return;
+ }
+
+ kernel_neon_begin();
+ chacha_doneon(state, dst, src, bytes, nrounds);
+ kernel_neon_end();
+}
+EXPORT_SYMBOL(chacha_crypt_arch);
+
+static int chacha_stream_xor(struct skcipher_request *req,
+ const struct chacha_ctx *ctx, const u8 *iv,
+ bool neon)
+{
+ struct skcipher_walk walk;
+ u32 state[16];
+ int err;
+
+ err = skcipher_walk_virt(&walk, req, false);
+
+ chacha_init_generic(state, ctx->key, iv);
+
+ while (walk.nbytes > 0) {
+ unsigned int nbytes = walk.nbytes;
+
+ if (nbytes < walk.total)
+ nbytes = round_down(nbytes, walk.stride);
+
+ if (!neon) {
+ chacha_doarm(walk.dst.virt.addr, walk.src.virt.addr,
+ nbytes, state, ctx->nrounds);
+ state[12] += DIV_ROUND_UP(nbytes, CHACHA_BLOCK_SIZE);
+ } else {
+ kernel_neon_begin();
+ chacha_doneon(state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes, ctx->nrounds);
+ kernel_neon_end();
+ }
+ err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+ }
+
+ return err;
+}
+
+static int do_chacha(struct skcipher_request *req, bool neon)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+ return chacha_stream_xor(req, ctx, req->iv, neon);
+}
+
+static int chacha_arm(struct skcipher_request *req)
+{
+ return do_chacha(req, false);
+}
+
+static int chacha_neon(struct skcipher_request *req)
+{
+ return do_chacha(req, neon_usable());
+}
+
+static int do_xchacha(struct skcipher_request *req, bool neon)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct chacha_ctx subctx;
+ u32 state[16];
+ u8 real_iv[16];
+
+ chacha_init_generic(state, ctx->key, req->iv);
+
+ if (!neon) {
+ hchacha_block_arm(state, subctx.key, ctx->nrounds);
+ } else {
+ kernel_neon_begin();
+ hchacha_block_neon(state, subctx.key, ctx->nrounds);
+ kernel_neon_end();
+ }
+ subctx.nrounds = ctx->nrounds;
+
+ memcpy(&real_iv[0], req->iv + 24, 8);
+ memcpy(&real_iv[8], req->iv + 16, 8);
+ return chacha_stream_xor(req, &subctx, real_iv, neon);
+}
+
+static int xchacha_arm(struct skcipher_request *req)
+{
+ return do_xchacha(req, false);
+}
+
+static int xchacha_neon(struct skcipher_request *req)
+{
+ return do_xchacha(req, neon_usable());
+}
+
+static struct skcipher_alg arm_algs[] = {
+ {
+ .base.cra_name = "chacha20",
+ .base.cra_driver_name = "chacha20-arm",
+ .base.cra_priority = 200,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = CHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .setkey = chacha20_setkey,
+ .encrypt = chacha_arm,
+ .decrypt = chacha_arm,
+ }, {
+ .base.cra_name = "xchacha20",
+ .base.cra_driver_name = "xchacha20-arm",
+ .base.cra_priority = 200,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = XCHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .setkey = chacha20_setkey,
+ .encrypt = xchacha_arm,
+ .decrypt = xchacha_arm,
+ }, {
+ .base.cra_name = "xchacha12",
+ .base.cra_driver_name = "xchacha12-arm",
+ .base.cra_priority = 200,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = XCHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .setkey = chacha12_setkey,
+ .encrypt = xchacha_arm,
+ .decrypt = xchacha_arm,
+ },
+};
+
+static struct skcipher_alg neon_algs[] = {
+ {
+ .base.cra_name = "chacha20",
+ .base.cra_driver_name = "chacha20-neon",
+ .base.cra_priority = 300,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = CHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .walksize = 4 * CHACHA_BLOCK_SIZE,
+ .setkey = chacha20_setkey,
+ .encrypt = chacha_neon,
+ .decrypt = chacha_neon,
+ }, {
+ .base.cra_name = "xchacha20",
+ .base.cra_driver_name = "xchacha20-neon",
+ .base.cra_priority = 300,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = XCHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .walksize = 4 * CHACHA_BLOCK_SIZE,
+ .setkey = chacha20_setkey,
+ .encrypt = xchacha_neon,
+ .decrypt = xchacha_neon,
+ }, {
+ .base.cra_name = "xchacha12",
+ .base.cra_driver_name = "xchacha12-neon",
+ .base.cra_priority = 300,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = XCHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .walksize = 4 * CHACHA_BLOCK_SIZE,
+ .setkey = chacha12_setkey,
+ .encrypt = xchacha_neon,
+ .decrypt = xchacha_neon,
+ }
+};
+
+static int __init chacha_simd_mod_init(void)
+{
+ int err;
+
+ err = crypto_register_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
+ if (err)
+ return err;
+
+ if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) {
+ int i;
+
+ switch (read_cpuid_part()) {
+ case ARM_CPU_PART_CORTEX_A7:
+ case ARM_CPU_PART_CORTEX_A5:
+ /*
+ * The Cortex-A7 and Cortex-A5 do not perform well with
+ * the NEON implementation but do incredibly with the
+ * scalar one and use less power.
+ */
+ for (i = 0; i < ARRAY_SIZE(neon_algs); i++)
+ neon_algs[i].base.cra_priority = 0;
+ break;
+ default:
+ static_branch_enable(&use_neon);
+ }
+
+ err = crypto_register_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
+ if (err)
+ crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
+ }
+ return err;
+}
+
+static void __exit chacha_simd_mod_fini(void)
+{
+ crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
+ if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON))
+ crypto_unregister_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
+}
+
+module_init(chacha_simd_mod_init);
+module_exit(chacha_simd_mod_fini);
+
+MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (scalar and NEON accelerated)");
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CRYPTO("chacha20");
+MODULE_ALIAS_CRYPTO("chacha20-arm");
+MODULE_ALIAS_CRYPTO("xchacha20");
+MODULE_ALIAS_CRYPTO("xchacha20-arm");
+MODULE_ALIAS_CRYPTO("xchacha12");
+MODULE_ALIAS_CRYPTO("xchacha12-arm");
+#ifdef CONFIG_KERNEL_MODE_NEON
+MODULE_ALIAS_CRYPTO("chacha20-neon");
+MODULE_ALIAS_CRYPTO("xchacha20-neon");
+MODULE_ALIAS_CRYPTO("xchacha12-neon");
+#endif
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