[CRYPTO] padlock: Driver for SHA1 / SHA256 algorithms

Support for SHA1 / SHA256 algorithms in VIA C7 processors.

Signed-off-by: Michal Ludvig <michal@logix.cz>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 339 insertions, 0 deletions

diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c
new file mode 100644
index 0000000..f701003
--- /dev/null
+++ b/drivers/crypto/padlock-sha.c
@@ -0,0 +1,339 @@
+/*
+ * Cryptographic API.
+ *
+ * Support for VIA PadLock hardware crypto engine.
+ *
+ * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/crypto.h>
+#include <linux/cryptohash.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/scatterlist.h>
+#include "padlock.h"
+
+#define SHA1_DEFAULT_FALLBACK	"sha1-generic"
+#define SHA1_DIGEST_SIZE        20
+#define SHA1_HMAC_BLOCK_SIZE    64
+
+#define SHA256_DEFAULT_FALLBACK "sha256-generic"
+#define SHA256_DIGEST_SIZE      32
+#define SHA256_HMAC_BLOCK_SIZE  64
+
+static char *sha1_fallback = SHA1_DEFAULT_FALLBACK;
+static char *sha256_fallback = SHA256_DEFAULT_FALLBACK;
+
+module_param(sha1_fallback, charp, 0644);
+module_param(sha256_fallback, charp, 0644);
+
+MODULE_PARM_DESC(sha1_fallback, "Fallback driver for SHA1. Default is "
+		 SHA1_DEFAULT_FALLBACK);
+MODULE_PARM_DESC(sha256_fallback, "Fallback driver for SHA256. Default is "
+		 SHA256_DEFAULT_FALLBACK);
+
+struct padlock_sha_ctx {
+	char		*data;
+	size_t		used;
+	int		bypass;
+	void (*f_sha_padlock)(const char *in, char *out, int count);
+	struct crypto_tfm *fallback_tfm;
+};
+
+static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
+{
+	return (struct padlock_sha_ctx *)(crypto_tfm_ctx(tfm));
+}
+
+/* We'll need aligned address on the stack */
+#define NEAREST_ALIGNED(ptr) \
+	((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
+
+static struct crypto_alg sha1_alg, sha256_alg;
+
+static void padlock_sha_bypass(struct crypto_tfm *tfm)
+{
+	if (ctx(tfm)->bypass)
+		return;
+
+	BUG_ON(!ctx(tfm)->fallback_tfm);
+
+	crypto_digest_init(ctx(tfm)->fallback_tfm);
+	if (ctx(tfm)->data && ctx(tfm)->used) {
+		struct scatterlist sg;
+
+		sg_set_buf(&sg, ctx(tfm)->data, ctx(tfm)->used);
+		crypto_digest_update(ctx(tfm)->fallback_tfm, &sg, 1);
+	}
+
+	ctx(tfm)->used = 0;
+	ctx(tfm)->bypass = 1;
+}
+
+static void padlock_sha_init(struct crypto_tfm *tfm)
+{
+	ctx(tfm)->used = 0;
+	ctx(tfm)->bypass = 0;
+}
+
+static void padlock_sha_update(struct crypto_tfm *tfm,
+			const uint8_t *data, unsigned int length)
+{
+	/* Our buffer is always one page. */
+	if (unlikely(!ctx(tfm)->bypass &&
+		     (ctx(tfm)->used + length > PAGE_SIZE)))
+		padlock_sha_bypass(tfm);
+
+	if (unlikely(ctx(tfm)->bypass)) {
+		struct scatterlist sg;
+		BUG_ON(!ctx(tfm)->fallback_tfm);
+		sg_set_buf(&sg, (uint8_t *)data, length);
+		crypto_digest_update(ctx(tfm)->fallback_tfm, &sg, 1);
+		return;
+	}
+
+	memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
+	ctx(tfm)->used += length;
+}
+
+static inline void padlock_output_block(uint32_t *src,
+		 	uint32_t *dst, size_t count)
+{
+	while (count--)
+		*dst++ = swab32(*src++);
+}
+
+void padlock_do_sha1(const char *in, char *out, int count)
+{
+	/* We can't store directly to *out as it may be unaligned. */
+	/* BTW Don't reduce the buffer size below 128 Bytes!
+	 *     PadLock microcode needs it that big. */
+	char buf[128+16];
+	char *result = NEAREST_ALIGNED(buf);
+
+	((uint32_t *)result)[0] = 0x67452301;
+	((uint32_t *)result)[1] = 0xEFCDAB89;
+	((uint32_t *)result)[2] = 0x98BADCFE;
+	((uint32_t *)result)[3] = 0x10325476;
+	((uint32_t *)result)[4] = 0xC3D2E1F0;
+ 
+	asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
+		      : "+S"(in), "+D"(result)
+		      : "c"(count), "a"(0));
+
+	padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
+}
+
+void padlock_do_sha256(const char *in, char *out, int count)
+{
+	/* We can't store directly to *out as it may be unaligned. */
+	/* BTW Don't reduce the buffer size below 128 Bytes!
+	 *     PadLock microcode needs it that big. */
+	char buf[128+16];
+	char *result = NEAREST_ALIGNED(buf);
+
+	((uint32_t *)result)[0] = 0x6A09E667;
+	((uint32_t *)result)[1] = 0xBB67AE85;
+	((uint32_t *)result)[2] = 0x3C6EF372;
+	((uint32_t *)result)[3] = 0xA54FF53A;
+	((uint32_t *)result)[4] = 0x510E527F;
+	((uint32_t *)result)[5] = 0x9B05688C;
+	((uint32_t *)result)[6] = 0x1F83D9AB;
+	((uint32_t *)result)[7] = 0x5BE0CD19;
+
+	asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
+		      : "+S"(in), "+D"(result)
+		      : "c"(count), "a"(0));
+
+	padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
+}
+
+static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
+{
+	if (unlikely(ctx(tfm)->bypass)) {
+		BUG_ON(!ctx(tfm)->fallback_tfm);
+		crypto_digest_final(ctx(tfm)->fallback_tfm, out);
+		ctx(tfm)->bypass = 0;
+		return;
+	}
+
+	/* Pass the input buffer to PadLock microcode... */
+	ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
+
+	ctx(tfm)->used = 0;
+}
+
+static int padlock_cra_init(struct crypto_tfm *tfm, const char *fallback_driver_name)
+{
+	/* For now we'll allocate one page. This
+	 * could eventually be configurable one day. */
+	ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
+	if (!ctx(tfm)->data)
+		return -ENOMEM;
+
+	/* Allocate a fallback and abort if it failed. */
+	ctx(tfm)->fallback_tfm = crypto_alloc_tfm(fallback_driver_name, 0);
+	if (!ctx(tfm)->fallback_tfm) {
+		printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
+		       fallback_driver_name);
+		free_page((unsigned long)(ctx(tfm)->data));
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
+{
+	ctx(tfm)->f_sha_padlock = padlock_do_sha1;
+
+	return padlock_cra_init(tfm, sha1_fallback);
+}
+
+static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
+{
+	ctx(tfm)->f_sha_padlock = padlock_do_sha256;
+
+	return padlock_cra_init(tfm, sha256_fallback);
+}
+
+static void padlock_cra_exit(struct crypto_tfm *tfm)
+{
+	if (ctx(tfm)->data) {
+		free_page((unsigned long)(ctx(tfm)->data));
+		ctx(tfm)->data = NULL;
+	}
+
+	BUG_ON(!ctx(tfm)->fallback_tfm);
+	crypto_free_tfm(ctx(tfm)->fallback_tfm);
+	ctx(tfm)->fallback_tfm = NULL;
+}
+
+static struct crypto_alg sha1_alg = {
+	.cra_name		=	"sha1",
+	.cra_driver_name	=	"sha1-padlock",
+	.cra_priority		=	PADLOCK_CRA_PRIORITY,
+	.cra_flags		=	CRYPTO_ALG_TYPE_DIGEST,
+	.cra_blocksize		=	SHA1_HMAC_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_list		=	LIST_HEAD_INIT(sha1_alg.cra_list),
+	.cra_init		=	padlock_sha1_cra_init,
+	.cra_exit		=	padlock_cra_exit,
+	.cra_u			=	{
+		.digest = {
+			.dia_digestsize	=	SHA1_DIGEST_SIZE,
+			.dia_init   	= 	padlock_sha_init,
+			.dia_update 	=	padlock_sha_update,
+			.dia_final  	=	padlock_sha_final,
+		}
+	}
+};
+
+static struct crypto_alg sha256_alg = {
+	.cra_name		=	"sha256",
+	.cra_driver_name	=	"sha256-padlock",
+	.cra_priority		=	PADLOCK_CRA_PRIORITY,
+	.cra_flags		=	CRYPTO_ALG_TYPE_DIGEST,
+	.cra_blocksize		=	SHA256_HMAC_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_list		=	LIST_HEAD_INIT(sha256_alg.cra_list),
+	.cra_init		=	padlock_sha256_cra_init,
+	.cra_exit		=	padlock_cra_exit,
+	.cra_u			=	{
+		.digest = {
+			.dia_digestsize	=	SHA256_DIGEST_SIZE,
+			.dia_init   	= 	padlock_sha_init,
+			.dia_update 	=	padlock_sha_update,
+			.dia_final  	=	padlock_sha_final,
+		}
+	}
+};
+
+static void __init padlock_sha_check_fallbacks(void)
+{
+	static struct crypto_tfm *tfm_sha1, *tfm_sha256;
+
+	/* We'll try to allocate one TFM for each fallback
+	 * to test that the modules are available. */
+	tfm_sha1 = crypto_alloc_tfm(sha1_fallback, 0);
+	if (!tfm_sha1) {
+		printk(KERN_WARNING PFX "Couldn't load fallback module for '%s'. Tried '%s'.\n",
+		       sha1_alg.cra_name, sha1_fallback);
+	} else {
+		printk(KERN_NOTICE PFX "Fallback for '%s' is driver '%s' (prio=%d)\n", sha1_alg.cra_name,
+		       crypto_tfm_alg_driver_name(tfm_sha1), crypto_tfm_alg_priority(tfm_sha1));
+		crypto_free_tfm(tfm_sha1);
+	}
+
+	tfm_sha256 = crypto_alloc_tfm(sha256_fallback, 0);
+	if (!tfm_sha256) {
+		printk(KERN_WARNING PFX "Couldn't load fallback module for '%s'. Tried '%s'.\n",
+		       sha256_alg.cra_name, sha256_fallback);
+	} else {
+		printk(KERN_NOTICE PFX "Fallback for '%s' is driver '%s' (prio=%d)\n", sha256_alg.cra_name,
+		       crypto_tfm_alg_driver_name(tfm_sha256), crypto_tfm_alg_priority(tfm_sha256));
+		crypto_free_tfm(tfm_sha256);
+	}
+}
+
+static int __init padlock_init(void)
+{
+	int rc = -ENODEV;
+
+	if (!cpu_has_phe) {
+		printk(KERN_ERR PFX "VIA PadLock Hash Engine not detected.\n");
+		return -ENODEV;
+	}
+
+	if (!cpu_has_phe_enabled) {
+		printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
+		return -ENODEV;
+	}
+
+	padlock_sha_check_fallbacks();
+
+	rc = crypto_register_alg(&sha1_alg);
+	if (rc)
+		goto out;
+
+	rc = crypto_register_alg(&sha256_alg);
+	if (rc)
+		goto out_unreg1;
+
+	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
+
+	return 0;
+
+out_unreg1:
+	crypto_unregister_alg(&sha1_alg);
+out:
+	printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
+	return rc;
+}
+
+static void __exit padlock_fini(void)
+{
+	crypto_unregister_alg(&sha1_alg);
+	crypto_unregister_alg(&sha256_alg);
+}
+
+module_init(padlock_init);
+module_exit(padlock_fini);
+
+MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michal Ludvig");
+
+MODULE_ALIAS("sha1-padlock");
+MODULE_ALIAS("sha256-padlock");