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1f4e477376
linux/drivers/crypto/geode-aes.c
Sebastian Siewior 1f4e477376 [CRYPTO] geode: relax in busy loop and care about return value 
The code waits in a busy loop until the hardware finishes the encryption
or decryption process. This wants a cpu_relax() :)
The busy loop finishes either if the encryption is done or if the counter
is zero. If the latter is true than the hardware failed. Since this
should not happen, leave sith a BUG().

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11 08:16:05 +11:00

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/* 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 <crypto/aes.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);
cpu_relax();
} 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;
int ret;
if (op->len == 0)
return 0;
/* If the source and destination is the same, then
* we need to turn on the coherent flags, otherwise
* we don't need to worry
*/
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_HIDDENKEY)) {
flags |= AES_CTRL_WRKEY;
_writefield(AES_WRITEKEY0_REG, op->key);
}
ret = do_crypt(op->src, op->dst, op->len, flags);
BUG_ON(ret);
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);
memcpy(op->iv, walk.iv, AES_IV_LENGTH);
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;
ret = geode_aes_crypt(op);
nbytes -= ret;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
memcpy(walk.iv, op->iv, AES_IV_LENGTH);
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);
memcpy(op->iv, walk.iv, AES_IV_LENGTH);
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;
ret = geode_aes_crypt(op);
nbytes -= ret;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
memcpy(walk.iv, op->iv, AES_IV_LENGTH);
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,
.ivsize = AES_IV_LENGTH,
}
}
};
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);
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