crypto: ghash - Add PCLMULQDQ accelerated implementation
PCLMULQDQ is used to accelerate the most time-consuming part of GHASH,
carry-less multiplication. More information about PCLMULQDQ can be
found at:
http://software.intel.com/en-us/articles/carry-less-multiplication-and-its-usage-for-computing-the-gcm-mode/
Because PCLMULQDQ changes XMM state, its usage must be enclosed with
kernel_fpu_begin/end, which can be used only in process context, the
acceleration is implemented as crypto_ahash. That is, request in soft
IRQ context will be defered to the cryptd kernel thread.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/arch/x86/crypto/ghash-clmulni-intel_glue.c b/arch/x86/crypto/ghash-clmulni-intel_glue.c
new file mode 100644
index 0000000..65d4096
--- /dev/null
+++ b/arch/x86/crypto/ghash-clmulni-intel_glue.c
@@ -0,0 +1,333 @@
+/*
+ * Accelerated GHASH implementation with Intel PCLMULQDQ-NI
+ * instructions. This file contains glue code.
+ *
+ * Copyright (c) 2009 Intel Corp.
+ * Author: Huang Ying <ying.huang@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/crypto.h>
+#include <crypto/algapi.h>
+#include <crypto/cryptd.h>
+#include <crypto/gf128mul.h>
+#include <crypto/internal/hash.h>
+#include <asm/i387.h>
+
+#define GHASH_BLOCK_SIZE 16
+#define GHASH_DIGEST_SIZE 16
+
+void clmul_ghash_mul(char *dst, const be128 *shash);
+
+void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
+ const be128 *shash);
+
+void clmul_ghash_setkey(be128 *shash, const u8 *key);
+
+struct ghash_async_ctx {
+ struct cryptd_ahash *cryptd_tfm;
+};
+
+struct ghash_ctx {
+ be128 shash;
+};
+
+struct ghash_desc_ctx {
+ u8 buffer[GHASH_BLOCK_SIZE];
+ u32 bytes;
+};
+
+static int ghash_init(struct shash_desc *desc)
+{
+ struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+
+ memset(dctx, 0, sizeof(*dctx));
+
+ return 0;
+}
+
+static int ghash_setkey(struct crypto_shash *tfm,
+ const u8 *key, unsigned int keylen)
+{
+ struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
+
+ if (keylen != GHASH_BLOCK_SIZE) {
+ crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+ return -EINVAL;
+ }
+
+ clmul_ghash_setkey(&ctx->shash, key);
+
+ return 0;
+}
+
+static int ghash_update(struct shash_desc *desc,
+ const u8 *src, unsigned int srclen)
+{
+ struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+ struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
+ u8 *dst = dctx->buffer;
+
+ kernel_fpu_begin();
+ if (dctx->bytes) {
+ int n = min(srclen, dctx->bytes);
+ u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
+
+ dctx->bytes -= n;
+ srclen -= n;
+
+ while (n--)
+ *pos++ ^= *src++;
+
+ if (!dctx->bytes)
+ clmul_ghash_mul(dst, &ctx->shash);
+ }
+
+ clmul_ghash_update(dst, src, srclen, &ctx->shash);
+ kernel_fpu_end();
+
+ if (srclen & 0xf) {
+ src += srclen - (srclen & 0xf);
+ srclen &= 0xf;
+ dctx->bytes = GHASH_BLOCK_SIZE - srclen;
+ while (srclen--)
+ *dst++ ^= *src++;
+ }
+
+ return 0;
+}
+
+static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
+{
+ u8 *dst = dctx->buffer;
+
+ if (dctx->bytes) {
+ u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
+
+ while (dctx->bytes--)
+ *tmp++ ^= 0;
+
+ kernel_fpu_begin();
+ clmul_ghash_mul(dst, &ctx->shash);
+ kernel_fpu_end();
+ }
+
+ dctx->bytes = 0;
+}
+
+static int ghash_final(struct shash_desc *desc, u8 *dst)
+{
+ struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+ struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
+ u8 *buf = dctx->buffer;
+
+ ghash_flush(ctx, dctx);
+ memcpy(dst, buf, GHASH_BLOCK_SIZE);
+
+ return 0;
+}
+
+static struct shash_alg ghash_alg = {
+ .digestsize = GHASH_DIGEST_SIZE,
+ .init = ghash_init,
+ .update = ghash_update,
+ .final = ghash_final,
+ .setkey = ghash_setkey,
+ .descsize = sizeof(struct ghash_desc_ctx),
+ .base = {
+ .cra_name = "__ghash",
+ .cra_driver_name = "__ghash-pclmulqdqni",
+ .cra_priority = 0,
+ .cra_flags = CRYPTO_ALG_TYPE_SHASH,
+ .cra_blocksize = GHASH_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct ghash_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(ghash_alg.base.cra_list),
+ },
+};
+
+static int ghash_async_init(struct ahash_request *req)
+{
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+ struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct ahash_request *cryptd_req = ahash_request_ctx(req);
+ struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+ if (irq_fpu_usable()) {
+ memcpy(cryptd_req, req, sizeof(*req));
+ ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
+ return crypto_ahash_init(cryptd_req);
+ } else {
+ struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+ struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
+
+ desc->tfm = child;
+ desc->flags = req->base.flags;
+ return crypto_shash_init(desc);
+ }
+}
+
+static int ghash_async_update(struct ahash_request *req)
+{
+ struct ahash_request *cryptd_req = ahash_request_ctx(req);
+
+ if (irq_fpu_usable()) {
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+ struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+ memcpy(cryptd_req, req, sizeof(*req));
+ ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
+ return crypto_ahash_update(cryptd_req);
+ } else {
+ struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+ return shash_ahash_update(req, desc);
+ }
+}
+
+static int ghash_async_final(struct ahash_request *req)
+{
+ struct ahash_request *cryptd_req = ahash_request_ctx(req);
+
+ if (irq_fpu_usable()) {
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+ struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+ memcpy(cryptd_req, req, sizeof(*req));
+ ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
+ return crypto_ahash_final(cryptd_req);
+ } else {
+ struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+ return crypto_shash_final(desc, req->result);
+ }
+}
+
+static int ghash_async_digest(struct ahash_request *req)
+{
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+ struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct ahash_request *cryptd_req = ahash_request_ctx(req);
+ struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+ if (irq_fpu_usable()) {
+ memcpy(cryptd_req, req, sizeof(*req));
+ ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
+ return crypto_ahash_digest(cryptd_req);
+ } else {
+ struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+ struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
+
+ desc->tfm = child;
+ desc->flags = req->base.flags;
+ return shash_ahash_digest(req, desc);
+ }
+}
+
+static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct crypto_ahash *child = &ctx->cryptd_tfm->base;
+ int err;
+
+ crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+ crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
+ & CRYPTO_TFM_REQ_MASK);
+ err = crypto_ahash_setkey(child, key, keylen);
+ crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
+ & CRYPTO_TFM_RES_MASK);
+
+ return 0;
+}
+
+static int ghash_async_init_tfm(struct crypto_tfm *tfm)
+{
+ struct cryptd_ahash *cryptd_tfm;
+ struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni", 0, 0);
+ if (IS_ERR(cryptd_tfm))
+ return PTR_ERR(cryptd_tfm);
+ ctx->cryptd_tfm = cryptd_tfm;
+ crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
+ sizeof(struct ahash_request) +
+ crypto_ahash_reqsize(&cryptd_tfm->base));
+
+ return 0;
+}
+
+static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
+{
+ struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ cryptd_free_ahash(ctx->cryptd_tfm);
+}
+
+static struct ahash_alg ghash_async_alg = {
+ .init = ghash_async_init,
+ .update = ghash_async_update,
+ .final = ghash_async_final,
+ .setkey = ghash_async_setkey,
+ .digest = ghash_async_digest,
+ .halg = {
+ .digestsize = GHASH_DIGEST_SIZE,
+ .base = {
+ .cra_name = "ghash",
+ .cra_driver_name = "ghash-clmulni",
+ .cra_priority = 400,
+ .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
+ .cra_blocksize = GHASH_BLOCK_SIZE,
+ .cra_type = &crypto_ahash_type,
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(ghash_async_alg.halg.base.cra_list),
+ .cra_init = ghash_async_init_tfm,
+ .cra_exit = ghash_async_exit_tfm,
+ },
+ },
+};
+
+static int __init ghash_pclmulqdqni_mod_init(void)
+{
+ int err;
+
+ if (!cpu_has_pclmulqdq) {
+ printk(KERN_INFO "Intel PCLMULQDQ-NI instructions are not"
+ " detected.\n");
+ return -ENODEV;
+ }
+
+ err = crypto_register_shash(&ghash_alg);
+ if (err)
+ goto err_out;
+ err = crypto_register_ahash(&ghash_async_alg);
+ if (err)
+ goto err_shash;
+
+ return 0;
+
+err_shash:
+ crypto_unregister_shash(&ghash_alg);
+err_out:
+ return err;
+}
+
+static void __exit ghash_pclmulqdqni_mod_exit(void)
+{
+ crypto_unregister_ahash(&ghash_async_alg);
+ crypto_unregister_shash(&ghash_alg);
+}
+
+module_init(ghash_pclmulqdqni_mod_init);
+module_exit(ghash_pclmulqdqni_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("GHASH Message Digest Algorithm, "
+ "acclerated by PCLMULQDQ-NI");
+MODULE_ALIAS("ghash");