/* Copyright (C) 2004-2006, Advanced Micro Devices, 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; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/crypto.h>
#include <linux/spinlock.h>
#include <crypto/algapi.h>
#include <asm/io.h>
#include <asm/delay.h>
#include "geode-aes.h"
/* Register definitions */
#define AES_CTRLA_REG 0x0000
#define AES_CTRL_START 0x01
#define AES_CTRL_DECRYPT 0x00
#define AES_CTRL_ENCRYPT 0x02
#define AES_CTRL_WRKEY 0x04
#define AES_CTRL_DCA 0x08
#define AES_CTRL_SCA 0x10
#define AES_CTRL_CBC 0x20
#define AES_INTR_REG 0x0008
#define AES_INTRA_PENDING (1 << 16)
#define AES_INTRB_PENDING (1 << 17)
#define AES_INTR_PENDING (AES_INTRA_PENDING | AES_INTRB_PENDING)
#define AES_INTR_MASK 0x07
#define AES_SOURCEA_REG 0x0010
#define AES_DSTA_REG 0x0014
#define AES_LENA_REG 0x0018
#define AES_WRITEKEY0_REG 0x0030
#define AES_WRITEIV0_REG 0x0040
/* A very large counter that is used to gracefully bail out of an
* operation in case of trouble
*/
#define AES_OP_TIMEOUT 0x50000
/* Static structures */
static void __iomem * _iobase;
static spinlock_t lock;
/* Write a 128 bit field (either a writable key or IV) */
static inline void
_writefield(u32 offset, void *value)
{
int i;
for(i = 0; i < 4; i++)
iowrite32(((u32 *) value)[i], _iobase + offset + (i * 4));
}
/* Read a 128 bit field (either a writable key or IV) */
static inline void
_readfield(u32 offset, void *value)
{
int i;
for(i = 0; i < 4; i++)
((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
}
static int
do_crypt(void *src, void *dst, int len, u32 flags)
{
u32 status;
u32 counter = AES_OP_TIMEOUT;
iowrite32(virt_to_phys(src), _iobase + AES_SOURCEA_REG);
iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
iowrite32(len, _iobase + AES_LENA_REG);
/* Start the operation */
iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
do
status = ioread32(_iobase + AES_INTR_REG);
while(!(status & AES_INTRA_PENDING) && --counter);
/* Clear the event */
iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
return counter ? 0 : 1;
}
static unsigned int
geode_aes_crypt(struct geode_aes_op *op)
{
u32 flags = 0;
unsigned long iflags;
if (op->len == 0 || op->src == op->dst)
return 0;
if (op->flags & AES_FLAGS_COHERENT)
flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
if (op->dir == AES_DIR_ENCRYPT)
flags |= AES_CTRL_ENCRYPT;
/* Start the critical section */
spin_lock_irqsave(&lock, iflags);
if (op->mode == AES_MODE_CBC) {
flags |= AES_CTRL_CBC;
_writefield(AES_WRITEIV0_REG, op->iv);
}
if (op->flags & AES_FLAGS_USRKEY) {
flags |= AES_CTRL_WRKEY;
_writefield(AES_WRITEKEY0_REG, op->key);
}
do_crypt(op->src, op->dst, op->len, flags);
if (op->mode == AES_MODE_CBC)
_readfield(AES_WRITEIV0_REG, op->iv);
spin_unlock_irqrestore(&lock, iflags);
return op->len;
}
/* CRYPTO-API Functions */
static int
geode_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int len)
{
struct geode_aes_op *op = crypto_tfm_ctx(tfm);
if (len != AES_KEY_LENGTH) {
tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
memcpy(op->key, key, len);
return 0;
}
static void
geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
struct geode_aes_op *op = crypto_tfm_ctx(tfm);
if ((out == NULL) || (in == NULL))
return;
op->src = (void *) in;
op->dst = (void *) out;
op->mode = AES_MODE_ECB;
op->flags = 0;
op->len = AES_MIN_BLOCK_SIZE;
op->dir = AES_DIR_ENCRYPT;
geode_aes_crypt(op);
}
static void
geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
struct geode_aes_op *op = crypto_tfm_ctx(tfm);
if ((out == NULL) || (in == NULL))
return;
op->src = (void *) in;
op->dst = (void *) out;
op->mode = AES_MODE_ECB;
op->flags = 0;
op->len = AES_MIN_BLOCK_SIZE;
op->dir = AES_DIR_DECRYPT;
geode_aes_crypt(op);
}
static struct crypto_alg geode_alg = {
.cra_name = "aes",
.cra_driver_name = "geode-aes-128",
.cra_priority = 300,
.cra_alignmask = 15,
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = AES_MIN_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct geode_aes_op),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(geode_alg.cra_list),
.cra_u = {
.cipher = {
.cia_min_keysize = AES_KEY_LENGTH,
.cia_max_keysize = AES_KEY_LENGTH,
.cia_setkey = geode_setkey,
.cia_encrypt = geode_encrypt,
.cia_decrypt = geode_decrypt
}
}
};
static int
geode_cbc_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err, ret;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while((nbytes = walk.nbytes)) {
op->src = walk.src.virt.addr,
op->dst = walk.dst.virt.addr;
op->mode = AES_MODE_CBC;
op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
op->dir = AES_DIR_DECRYPT;
memcpy(op->iv, walk.iv, AES_IV_LENGTH);
ret = geode_aes_crypt(op);
memcpy(walk.iv, op->iv, AES_IV_LENGTH);
nbytes -= ret;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
static int
geode_cbc_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err, ret;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while((nbytes = walk.nbytes)) {
op->src = walk.src.virt.addr,
op->dst = walk.dst.virt.addr;
op->mode = AES_MODE_CBC;
op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
op->dir = AES_DIR_ENCRYPT;
memcpy(op->iv, walk.iv, AES_IV_LENGTH);
ret = geode_aes_crypt(op);
nbytes -= ret;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
static struct crypto_alg geode_cbc_alg = {
.cra_name = "cbc(aes)",
.cra_driver_name = "cbc-aes-geode-128",
.cra_priority = 400,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
.cra_blocksize = AES_MIN_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct geode_aes_op),
.cra_alignmask = 15,
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(geode_cbc_alg.cra_list),
.cra_u = {
.blkcipher = {
.min_keysize = AES_KEY_LENGTH,
.max_keysize = AES_KEY_LENGTH,
.setkey = geode_setkey,
.encrypt = geode_cbc_encrypt,
.decrypt = geode_cbc_decrypt,
}
}
};
static int
geode_ecb_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err, ret;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while((nbytes = walk.nbytes)) {
op->src = walk.src.virt.addr,
op->dst = walk.dst.virt.addr;
op->mode = AES_MODE_ECB;
op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
op->dir = AES_DIR_DECRYPT;
ret = geode_aes_crypt(op);
nbytes -= ret;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
static int
geode_ecb_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err, ret;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while((nbytes = walk.nbytes)) {
op->src = walk.src.virt.addr,
op->dst = walk.dst.virt.addr;
op->mode = AES_MODE_ECB;
op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
op->dir = AES_DIR_ENCRYPT;
ret = geode_aes_crypt(op);
nbytes -= ret;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
static struct crypto_alg geode_ecb_alg = {
.cra_name = "ecb(aes)",
.cra_driver_name = "ecb-aes-geode-128",
.cra_priority = 400,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
.cra_blocksize = AES_MIN_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct geode_aes_op),
.cra_alignmask = 15,
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(geode_ecb_alg.cra_list),
.cra_u = {
.blkcipher = {
.min_keysize = AES_KEY_LENGTH,
.max_keysize = AES_KEY_LENGTH,
.setkey = geode_setkey,
.encrypt = geode_ecb_encrypt,
.decrypt = geode_ecb_decrypt,
}
}
};
static void
geode_aes_remove(struct pci_dev *dev)
{
crypto_unregister_alg(&geode_alg);
crypto_unregister_alg(&geode_ecb_alg);
crypto_unregister_alg(&geode_cbc_alg);
pci_iounmap(dev, _iobase);
_iobase = NULL;
pci_release_regions(dev);
pci_disable_device(dev);
}
static int
geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
int ret;
if ((ret = pci_enable_device(dev)))
return ret;
if ((ret = pci_request_regions(dev, "geode-aes-128")))
goto eenable;
_iobase = pci_iomap(dev, 0, 0);
if (_iobase == NULL) {
ret = -ENOMEM;
goto erequest;
}
spin_lock_init(&lock);
/* Clear any pending activity */
iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
if ((ret = crypto_register_alg(&geode_alg)))
goto eiomap;
if ((ret = crypto_register_alg(&geode_ecb_alg)))
goto ealg;
if ((ret = crypto_register_alg(&geode_cbc_alg)))
goto eecb;
printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled.\n");
return 0;
eecb:
crypto_unregister_alg(&geode_ecb_alg);
ealg:
crypto_unregister_alg(&geode_alg);
eiomap:
pci_iounmap(dev, _iobase);
erequest:
pci_release_regions(dev);
eenable:
pci_disable_device(dev);
printk(KERN_ERR "geode-aes: GEODE AES initialization failed.\n");
return ret;
}
static struct pci_device_id geode_aes_tbl[] = {
{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES, PCI_ANY_ID, PCI_ANY_ID} ,
{ 0, }
};
MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
static struct pci_driver geode_aes_driver = {
.name = "Geode LX AES",
.id_table = geode_aes_tbl,
.probe = geode_aes_probe,
.remove = __devexit_p(geode_aes_remove)
};
static int __init
geode_aes_init(void)
{
return pci_register_driver(&geode_aes_driver);
}
static void __exit
geode_aes_exit(void)
{
pci_unregister_driver(&geode_aes_driver);
}
MODULE_AUTHOR("Advanced Micro Devices, Inc.");
MODULE_DESCRIPTION("Geode LX Hardware AES driver");
MODULE_LICENSE("GPL");
module_init(geode_aes_init);
module_exit(geode_aes_exit);
