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crypto: padlock-aes - work around Nano CPU errata in CBC mode

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Extend previous workarounds for the prefetch bug to cover CBC mode,
clean up the code a bit.

Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
Acked-by: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Chuck Ebbert 2009-06-18 19:31:09 +08:00 committed by Herbert Xu
parent a76c1c23d0
commit 8d8409f773
1 changed files with 65 additions and 18 deletions
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83
drivers/crypto/padlock-aes.c
View file

@ -22,11 +22,16 @@
#include <asm/i387.h>
#include "padlock.h"
/* number of data blocks actually fetched for each xcrypt insn */
/*
* Number of data blocks actually fetched for each xcrypt insn.
* Processors with prefetch errata will fetch extra blocks.
*/
static unsigned int ecb_fetch_blocks = 2;
static unsigned int cbc_fetch_blocks = 1;
#define MAX_ECB_FETCH_BLOCKS (8)
#define ecb_fetch_bytes (ecb_fetch_blocks * AES_BLOCK_SIZE)
static unsigned int cbc_fetch_blocks = 1;
#define MAX_CBC_FETCH_BLOCKS (4)
#define cbc_fetch_bytes (cbc_fetch_blocks * AES_BLOCK_SIZE)
/* Control word. */
@ -180,7 +185,7 @@ static inline void padlock_store_cword(struct cword *cword)
* should be used only inside the irq_ts_save/restore() context
*/
static inline void padlock_xcrypt(const u8 *input, u8 *output, void *key,
static inline void rep_xcrypt_ecb(const u8 *input, u8 *output, void *key,
struct cword *control_word, int count)
{
asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
@ -188,32 +193,65 @@ static inline void padlock_xcrypt(const u8 *input, u8 *output, void *key,
: "d"(control_word), "b"(key), "c"(count));
}
static void aes_crypt_copy(const u8 *in, u8 *out, u32 *key,
static inline u8 *rep_xcrypt_cbc(const u8 *input, u8 *output, void *key,
u8 *iv, struct cword *control_word, int count)
{
asm volatile (".byte 0xf3,0x0f,0xa7,0xd0" /* rep xcryptcbc */
: "+S" (input), "+D" (output), "+a" (iv)
: "d" (control_word), "b" (key), "c" (count));
return iv;
}
static void ecb_crypt_copy(const u8 *in, u8 *out, u32 *key,
struct cword *cword, int count)
{
/*
* Padlock prefetches extra data so we must provide mapped input buffers.
* Assume there are at least 16 bytes of stack already in use.
*/
u8 buf[AES_BLOCK_SIZE * 7 + PADLOCK_ALIGNMENT - 1];
u8 buf[AES_BLOCK_SIZE * (MAX_ECB_FETCH_BLOCKS - 1) + PADLOCK_ALIGNMENT - 1];
u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
memcpy(tmp, in, count * AES_BLOCK_SIZE);
padlock_xcrypt(tmp, out, key, cword, count);
rep_xcrypt_ecb(tmp, out, key, cword, count);
}
static inline void aes_crypt(const u8 *in, u8 *out, u32 *key,
static u8 *cbc_crypt_copy(const u8 *in, u8 *out, u32 *key,
u8 *iv, struct cword *cword, int count)
{
/*
* Padlock prefetches extra data so we must provide mapped input buffers.
* Assume there are at least 16 bytes of stack already in use.
*/
u8 buf[AES_BLOCK_SIZE * (MAX_CBC_FETCH_BLOCKS - 1) + PADLOCK_ALIGNMENT - 1];
u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
memcpy(tmp, in, count * AES_BLOCK_SIZE);
return rep_xcrypt_cbc(tmp, out, key, iv, cword, count);
}
static inline void ecb_crypt(const u8 *in, u8 *out, u32 *key,
struct cword *cword, int count)
{
/* Padlock in ECB mode fetches at least ecb_fetch_bytes of data.
* We could avoid some copying here but it's probably not worth it.
*/
if (unlikely(((unsigned long)in & PAGE_SIZE) + ecb_fetch_bytes > PAGE_SIZE)) {
aes_crypt_copy(in, out, key, cword, count);
ecb_crypt_copy(in, out, key, cword, count);
return;
}
padlock_xcrypt(in, out, key, cword, count);
rep_xcrypt_ecb(in, out, key, cword, count);
}
static inline u8 *cbc_crypt(const u8 *in, u8 *out, u32 *key,
u8 *iv, struct cword *cword, int count)
{
/* Padlock in CBC mode fetches at least cbc_fetch_bytes of data. */
if (unlikely(((unsigned long)in & PAGE_SIZE) + cbc_fetch_bytes > PAGE_SIZE))
return cbc_crypt_copy(in, out, key, iv, cword, count);
return rep_xcrypt_cbc(in, out, key, iv, cword, count);
}
static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key,
@ -222,7 +260,7 @@ static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key,
u32 initial = count & (ecb_fetch_blocks - 1);
if (count < ecb_fetch_blocks) {
aes_crypt(input, output, key, control_word, count);
ecb_crypt(input, output, key, control_word, count);
return;
}
@ -239,10 +277,19 @@ static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key,
static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key,
u8 *iv, void *control_word, u32 count)
{
/* rep xcryptcbc */
asm volatile (".byte 0xf3,0x0f,0xa7,0xd0"
u32 initial = count & (cbc_fetch_blocks - 1);
if (count < cbc_fetch_blocks)
return cbc_crypt(input, output, key, iv, control_word, count);
if (initial)
asm volatile (".byte 0xf3,0x0f,0xa7,0xd0" /* rep xcryptcbc */
: "+S" (input), "+D" (output), "+a" (iv)
: "d" (control_word), "b" (key), "c" (count));
asm volatile (".byte 0xf3,0x0f,0xa7,0xd0" /* rep xcryptcbc */
: "+S" (input), "+D" (output), "+a" (iv)
: "d" (control_word), "b" (key), "c" (count));
: "d" (control_word), "b" (key), "c" (count-initial));
return iv;
}
@ -253,7 +300,7 @@ static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
padlock_reset_key(&ctx->cword.encrypt);
ts_state = irq_ts_save();
aes_crypt(in, out, ctx->E, &ctx->cword.encrypt, 1);
ecb_crypt(in, out, ctx->E, &ctx->cword.encrypt, 1);
irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.encrypt);
}
@ -265,7 +312,7 @@ static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
padlock_reset_key(&ctx->cword.encrypt);
ts_state = irq_ts_save();
aes_crypt(in, out, ctx->D, &ctx->cword.decrypt, 1);
ecb_crypt(in, out, ctx->D, &ctx->cword.decrypt, 1);
irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.encrypt);
}
@ -482,8 +529,8 @@ static int __init padlock_init(void)
printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n");
if (c->x86 == 6 && c->x86_model == 15 && c->x86_mask == 2) {
ecb_fetch_blocks = 8;
cbc_fetch_blocks = 4; /* NOTE: notused */
ecb_fetch_blocks = MAX_ECB_FETCH_BLOCKS;
cbc_fetch_blocks = MAX_CBC_FETCH_BLOCKS;
printk(KERN_NOTICE PFX "VIA Nano stepping 2 detected: enabling workaround.\n");
}