[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 000000000000..f7010038033b
--- /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");