/*
* 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 <crypto/internal/hash.h>
#include <crypto/sha.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include <asm/i387.h>
#include "padlock.h"
struct padlock_sha_ctx {
char *data;
size_t used;
int bypass;
void (*f_sha_padlock)(const char *in, char *out, int count);
struct shash_desc *fallback;
};
static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
{
return 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 int padlock_sha_bypass(struct crypto_tfm *tfm)
{
int err = 0;
if (ctx(tfm)->bypass)
goto out;
err = crypto_shash_init(ctx(tfm)->fallback);
if (err)
goto out;
if (ctx(tfm)->data && ctx(tfm)->used)
err = crypto_shash_update(ctx(tfm)->fallback, ctx(tfm)->data,
ctx(tfm)->used);
ctx(tfm)->used = 0;
ctx(tfm)->bypass = 1;
out:
return err;
}
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)
{
int err;
/* Our buffer is always one page. */
if (unlikely(!ctx(tfm)->bypass &&
(ctx(tfm)->used + length > PAGE_SIZE))) {
err = padlock_sha_bypass(tfm);
BUG_ON(err);
}
if (unlikely(ctx(tfm)->bypass)) {
err = crypto_shash_update(ctx(tfm)->fallback, data, length);
BUG_ON(err);
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++);
}
static 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);
int ts_state;
((uint32_t *)result)[0] = SHA1_H0;
((uint32_t *)result)[1] = SHA1_H1;
((uint32_t *)result)[2] = SHA1_H2;
((uint32_t *)result)[3] = SHA1_H3;
((uint32_t *)result)[4] = SHA1_H4;
/* prevent taking the spurious DNA fault with padlock. */
ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
: "+S"(in), "+D"(result)
: "c"(count), "a"(0));
irq_ts_restore(ts_state);
padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
}
static 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);
int ts_state;
((uint32_t *)result)[0] = SHA256_H0;
((uint32_t *)result)[1] = SHA256_H1;
((uint32_t *)result)[2] = SHA256_H2;
((uint32_t *)result)[3] = SHA256_H3;
((uint32_t *)result)[4] = SHA256_H4;
((uint32_t *)result)[5] = SHA256_H5;
((uint32_t *)result)[6] = SHA256_H6;
((uint32_t *)result)[7] = SHA256_H7;
/* prevent taking the spurious DNA fault with padlock. */
ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
: "+S"(in), "+D"(result)
: "c"(count), "a"(0));
irq_ts_restore(ts_state);
padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
}
static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
{
int err;
if (unlikely(ctx(tfm)->bypass)) {
err = crypto_shash_final(ctx(tfm)->fallback, out);
BUG_ON(err);
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 = tfm->__crt_alg->cra_name;
struct crypto_shash *fallback_tfm;
int err = -ENOMEM;
/* 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)
goto out;
/* Allocate a fallback and abort if it failed. */
fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback_tfm)) {
printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
fallback_driver_name);
err = PTR_ERR(fallback_tfm);
goto out_free_page;
}
ctx(tfm)->fallback = kmalloc(sizeof(struct shash_desc) +
crypto_shash_descsize(fallback_tfm),
GFP_KERNEL);
if (!ctx(tfm)->fallback)
goto out_free_tfm;
ctx(tfm)->fallback->tfm = fallback_tfm;
ctx(tfm)->fallback->flags = 0;
return 0;
out_free_tfm:
crypto_free_shash(fallback_tfm);
out_free_page:
free_page((unsigned long)(ctx(tfm)->data));
out:
return err;
}
static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
{
ctx(tfm)->f_sha_padlock = padlock_do_sha1;
return padlock_cra_init(tfm);
}
static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
{
ctx(tfm)->f_sha_padlock = padlock_do_sha256;
return padlock_cra_init(tfm);
}
static void padlock_cra_exit(struct crypto_tfm *tfm)
{
if (ctx(tfm)->data) {
free_page((unsigned long)(ctx(tfm)->data));
ctx(tfm)->data = NULL;
}
crypto_free_shash(ctx(tfm)->fallback->tfm);
kzfree(ctx(tfm)->fallback);
}
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 |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = SHA1_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 |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = SHA256_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 int __init padlock_init(void)
{
int rc = -ENODEV;
if (!cpu_has_phe) {
printk(KERN_NOTICE PFX "VIA PadLock Hash Engine not detected.\n");
return -ENODEV;
}
if (!cpu_has_phe_enabled) {
printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
return -ENODEV;
}
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-all");
MODULE_ALIAS("sha256-all");
MODULE_ALIAS("sha1-padlock");
MODULE_ALIAS("sha256-padlock");
