This patch adds GHASH routines to VMX module in order to
make use of VMX cryptographic acceleration instructions
on Power 8 CPU.
Signed-off-by: Leonidas S. Barbosa <leosilva@xxxxxxxxxxxxxxxxxx>
---
drivers/crypto/vmx/ghash.c | 214 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 214 insertions(+)
create mode 100644 drivers/crypto/vmx/ghash.c
diff --git a/drivers/crypto/vmx/ghash.c b/drivers/crypto/vmx/ghash.c
new file mode 100644
index 0000000..d0ffe27
--- /dev/null
+++ b/drivers/crypto/vmx/ghash.c
@@ -0,0 +1,214 @@
+/**
+ * GHASH routines supporting VMX instructions on the Power 8
+ *
+ * Copyright (C) 2015 International Business Machines Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 only.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Author: Marcelo Henrique Cerri <mhcerri@xxxxxxxxxx>
+ */
+
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/crypto.h>
+#include <linux/delay.h>
+#include <linux/hardirq.h>
+#include <asm/switch_to.h>
+#include <crypto/aes.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/internal/hash.h>
+#include <crypto/b128ops.h>
+
+#define IN_INTERRUPT in_interrupt()
+
+#define GHASH_BLOCK_SIZE (16)
+#define GHASH_DIGEST_SIZE (16)
+#define GHASH_KEY_LEN (16)
+
+void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
+void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
+void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
+ const u8 *in,size_t len);
+
+struct p8_ghash_ctx {
+ u128 htable[16];
+ struct crypto_shash *fallback;
+};
+
+struct p8_ghash_desc_ctx {
+ u64 shash[2];
+ u8 buffer[GHASH_DIGEST_SIZE];
+ int bytes;
+ struct shash_desc fallback_desc;
+};
+
+static int p8_ghash_init_tfm(struct crypto_tfm *tfm)
+{
+ const char *alg;
+ struct crypto_shash *fallback;
+ struct crypto_shash *shash_tfm = __crypto_shash_cast(tfm);
+ struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ if (!(alg = crypto_tfm_alg_name(tfm))) {
+ printk(KERN_ERR "Failed to get algorithm name.\n");
+ return -ENOENT;
+ }
+
+ fallback = crypto_alloc_shash(alg, 0 ,CRYPTO_ALG_NEED_FALLBACK);
+ if (IS_ERR(fallback)) {
+ printk(KERN_ERR "Failed to allocate transformation for '%s': %ld\n",
+ alg, PTR_ERR(fallback));
+ return PTR_ERR(fallback);
+ }
+ printk(KERN_INFO "Using '%s' as fallback implementation.\n",
+ crypto_tfm_alg_driver_name(crypto_shash_tfm(fallback)));
+
+ crypto_shash_set_flags(fallback,
+ crypto_shash_get_flags((struct crypto_shash *) tfm));
+ ctx->fallback = fallback;
+
+ shash_tfm->descsize = sizeof(struct p8_ghash_desc_ctx)
+ + crypto_shash_descsize(fallback);
+
+ return 0;
+}
+
+static void p8_ghash_exit_tfm(struct crypto_tfm *tfm)
+{
+ struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ if (ctx->fallback) {
+ crypto_free_shash(ctx->fallback);
+ ctx->fallback = NULL;
+ }
+}
+
+static int p8_ghash_init(struct shash_desc *desc)
+{
+ struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
+ struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+
+ dctx->bytes = 0;
+ memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
+ dctx->fallback_desc.tfm = ctx->fallback;
+ dctx->fallback_desc.flags = desc->flags;
+ return crypto_shash_init(&dctx->fallback_desc);
+}
+
+static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));
+
+ if (keylen != GHASH_KEY_LEN)
+ return -EINVAL;
+
+ pagefault_disable();
+ enable_kernel_altivec();
+ enable_kernel_fp();
+ gcm_init_p8(ctx->htable, (const u64 *) key);
+ pagefault_enable();
+ return crypto_shash_setkey(ctx->fallback, key, keylen);
+}
+
+static int p8_ghash_update(struct shash_desc *desc,
+ const u8 *src, unsigned int srclen)
+{
+ unsigned int len;
+ struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
+ struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+
+ if (IN_INTERRUPT) {
+ return crypto_shash_update(&dctx->fallback_desc, src, srclen);
+ } else {
+ if (dctx->bytes) {
+ if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
+ memcpy(dctx->buffer + dctx->bytes, src, srclen);
+ dctx->bytes += srclen;
+ return 0;
+ }
+ memcpy(dctx->buffer + dctx->bytes, src,
+ GHASH_DIGEST_SIZE - dctx->bytes);
+ pagefault_disable();
+ enable_kernel_altivec();
+ enable_kernel_fp();
+ gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
+ GHASH_DIGEST_SIZE);
+ pagefault_enable();
+ src += GHASH_DIGEST_SIZE - dctx->bytes;
+ srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
+ dctx->bytes = 0;
+ }
+ len = srclen & ~(GHASH_DIGEST_SIZE - 1);
+ if (len) {
+ pagefault_disable();
+ enable_kernel_altivec();
+ enable_kernel_fp();
+ gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
+ pagefault_enable();
+ src += len;
+ srclen -= len;
+ }
+ if (srclen) {
+ memcpy(dctx->buffer, src, srclen);
+ dctx->bytes = srclen;
+ }
+ return 0;
+ }
+}
+
+static int p8_ghash_final(struct shash_desc *desc, u8 *out)
+{
+ int i;
+ struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
+ struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+
+ if (IN_INTERRUPT) {
+ return crypto_shash_final(&dctx->fallback_desc, out);
+ } else {
+ if (dctx->bytes) {
+ for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
+ dctx->buffer[i] = 0;
+ pagefault_disable();
+ enable_kernel_altivec();
+ enable_kernel_fp();
+ gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
+ GHASH_DIGEST_SIZE);
+ pagefault_enable();
+ dctx->bytes = 0;
+ }
+ memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
+ return 0;
+ }
+}
+
+struct shash_alg p8_ghash_alg = {
+ .digestsize = GHASH_DIGEST_SIZE,
+ .init = p8_ghash_init,
+ .update = p8_ghash_update,
+ .final = p8_ghash_final,
+ .setkey = p8_ghash_setkey,
+ .descsize = sizeof(struct p8_ghash_desc_ctx),
+ .base = {
+ .cra_name = "ghash",
+ .cra_driver_name = "p8_ghash",
+ .cra_priority = 1000,
+ .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_NEED_FALLBACK,
+ .cra_blocksize = GHASH_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct p8_ghash_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_init = p8_ghash_init_tfm,
+ .cra_exit = p8_ghash_exit_tfm,
+ },
+};
--
2.1.0
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