[PATCH 2/5] Glue code for optmized Chacha20 implementation for ppc64le.
Danny Tsen
dtsen at linux.ibm.com
Tue Apr 25 04:47:23 AEST 2023
Signed-off-by: Danny Tsen <dtsen at linux.ibm.com>
---
arch/powerpc/crypto/chacha-p10-glue.c | 223 ++++++++++++++++++++++++++
1 file changed, 223 insertions(+)
create mode 100644 arch/powerpc/crypto/chacha-p10-glue.c
diff --git a/arch/powerpc/crypto/chacha-p10-glue.c b/arch/powerpc/crypto/chacha-p10-glue.c
new file mode 100644
index 000000000000..cefb150e7b3c
--- /dev/null
+++ b/arch/powerpc/crypto/chacha-p10-glue.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PowerPC P10 (ppc64le) accelerated ChaCha and XChaCha stream ciphers,
+ * including ChaCha20 (RFC7539)
+ *
+ * Copyright 2023- IBM Inc. All rights reserved.
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/internal/chacha.h>
+#include <crypto/internal/simd.h>
+#include <crypto/internal/skcipher.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/cpufeature.h>
+#include <linux/sizes.h>
+#include <asm/simd.h>
+#include <asm/switch_to.h>
+
+asmlinkage void chacha_p10le_8x(u32 *state, u8 *dst, const u8 *src,
+ unsigned int len, int nrounds);
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_p10);
+
+static void vsx_begin(void)
+{
+ preempt_disable();
+ enable_kernel_vsx();
+}
+
+static void vsx_end(void)
+{
+ disable_kernel_vsx();
+ preempt_enable();
+}
+
+static void chacha_p10_do_8x(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds)
+{
+ unsigned int l = bytes & ~0x0FF;
+
+ if (l > 0) {
+ chacha_p10le_8x(state, dst, src, l, nrounds);
+ bytes -= l;
+ src += l;
+ dst += l;
+ state[12] += l / CHACHA_BLOCK_SIZE;
+ }
+
+ if (bytes > 0)
+ chacha_crypt_generic(state, dst, src, bytes, nrounds);
+}
+
+void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
+{
+ hchacha_block_generic(state, stream, nrounds);
+}
+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 (!static_branch_likely(&have_p10) || bytes <= CHACHA_BLOCK_SIZE ||
+ !crypto_simd_usable())
+ return chacha_crypt_generic(state, dst, src, bytes, nrounds);
+
+ do {
+ unsigned int todo = min_t(unsigned int, bytes, SZ_4K);
+
+ vsx_begin();
+ chacha_p10_do_8x(state, dst, src, todo, nrounds);
+ vsx_end();
+
+ bytes -= todo;
+ src += todo;
+ dst += todo;
+ } while (bytes);
+}
+EXPORT_SYMBOL(chacha_crypt_arch);
+
+static int chacha_p10_stream_xor(struct skcipher_request *req,
+ const struct chacha_ctx *ctx, const u8 *iv)
+{
+ struct skcipher_walk walk;
+ u32 state[16];
+ int err;
+
+ err = skcipher_walk_virt(&walk, req, false);
+ if (err)
+ return err;
+
+ chacha_init_generic(state, ctx->key, iv);
+
+ while (walk.nbytes > 0) {
+ unsigned int nbytes = walk.nbytes;
+
+ if (nbytes < walk.total)
+ nbytes = rounddown(nbytes, walk.stride);
+
+ if (!static_branch_likely(&have_p10) ||
+ !crypto_simd_usable()) {
+ chacha_crypt_generic(state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes,
+ ctx->nrounds);
+ } else {
+ vsx_begin();
+ chacha_p10_do_8x(state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes, ctx->nrounds);
+ vsx_end();
+ }
+ err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+ if (err)
+ break;
+ }
+
+ return err;
+}
+
+static int chacha_p10(struct skcipher_request *req)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+ return chacha_p10_stream_xor(req, ctx, req->iv);
+}
+
+static int xchacha_p10(struct skcipher_request *req)
+{
+ 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);
+ hchacha_block_arch(state, subctx.key, ctx->nrounds);
+ subctx.nrounds = ctx->nrounds;
+
+ memcpy(&real_iv[0], req->iv + 24, 8);
+ memcpy(&real_iv[8], req->iv + 16, 8);
+ return chacha_p10_stream_xor(req, &subctx, real_iv);
+}
+
+static struct skcipher_alg algs[] = {
+ {
+ .base.cra_name = "chacha20",
+ .base.cra_driver_name = "chacha20-p10",
+ .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,
+ .setkey = chacha20_setkey,
+ .encrypt = chacha_p10,
+ .decrypt = chacha_p10,
+ }, {
+ .base.cra_name = "xchacha20",
+ .base.cra_driver_name = "xchacha20-p10",
+ .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,
+ .setkey = chacha20_setkey,
+ .encrypt = xchacha_p10,
+ .decrypt = xchacha_p10,
+ }, {
+ .base.cra_name = "xchacha12",
+ .base.cra_driver_name = "xchacha12-p10",
+ .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,
+ .setkey = chacha12_setkey,
+ .encrypt = xchacha_p10,
+ .decrypt = xchacha_p10,
+ }
+};
+
+static int __init chacha_p10_init(void)
+{
+ static_branch_enable(&have_p10);
+
+ return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
+ crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
+}
+
+static void __exit chacha_p10_exit(void)
+{
+ crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
+}
+
+module_cpu_feature_match(PPC_MODULE_FEATURE_P10, chacha_p10_init);
+module_exit(chacha_p10_exit);
+
+MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (P10 accelerated)");
+MODULE_AUTHOR("Danny Tsen <dtsen at linux.ibm.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CRYPTO("chacha20");
+MODULE_ALIAS_CRYPTO("chacha20-p10");
+MODULE_ALIAS_CRYPTO("xchacha20");
+MODULE_ALIAS_CRYPTO("xchacha20-p10");
+MODULE_ALIAS_CRYPTO("xchacha12");
+MODULE_ALIAS_CRYPTO("xchacha12-p10");
--
2.31.1
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