Commit 8d8409f7 authored by Chuck Ebbert's avatar Chuck Ebbert Committed by Herbert Xu

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

Extend previous workarounds for the prefetch bug to cover CBC mode,
clean up the code a bit.
Signed-off-by: default avatarChuck Ebbert <cebbert@redhat.com>
Acked-by: default avatarHarald Welte <HaraldWelte@viatech.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent a76c1c23
...@@ -22,11 +22,16 @@ ...@@ -22,11 +22,16 @@
#include <asm/i387.h> #include <asm/i387.h>
#include "padlock.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 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) #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) #define cbc_fetch_bytes (cbc_fetch_blocks * AES_BLOCK_SIZE)
/* Control word. */ /* Control word. */
...@@ -180,7 +185,7 @@ static inline void padlock_store_cword(struct cword *cword) ...@@ -180,7 +185,7 @@ static inline void padlock_store_cword(struct cword *cword)
* should be used only inside the irq_ts_save/restore() context * 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) struct cword *control_word, int count)
{ {
asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */ 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, ...@@ -188,32 +193,65 @@ static inline void padlock_xcrypt(const u8 *input, u8 *output, void *key,
: "d"(control_word), "b"(key), "c"(count)); : "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) struct cword *cword, int count)
{ {
/* /*
* Padlock prefetches extra data so we must provide mapped input buffers. * Padlock prefetches extra data so we must provide mapped input buffers.
* Assume there are at least 16 bytes of stack already in use. * 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); u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
memcpy(tmp, in, count * AES_BLOCK_SIZE); 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) struct cword *cword, int count)
{ {
/* Padlock in ECB mode fetches at least ecb_fetch_bytes of data. /* 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. * 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)) { 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; 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, 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, ...@@ -222,7 +260,7 @@ static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key,
u32 initial = count & (ecb_fetch_blocks - 1); u32 initial = count & (ecb_fetch_blocks - 1);
if (count < ecb_fetch_blocks) { if (count < ecb_fetch_blocks) {
aes_crypt(input, output, key, control_word, count); ecb_crypt(input, output, key, control_word, count);
return; return;
} }
...@@ -239,10 +277,19 @@ static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key, ...@@ -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, static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key,
u8 *iv, void *control_word, u32 count) u8 *iv, void *control_word, u32 count)
{ {
/* rep xcryptcbc */ u32 initial = count & (cbc_fetch_blocks - 1);
asm volatile (".byte 0xf3,0x0f,0xa7,0xd0"
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) : "+S" (input), "+D" (output), "+a" (iv)
: "d" (control_word), "b" (key), "c" (count)); : "d" (control_word), "b" (key), "c" (count-initial));
return iv; return iv;
} }
...@@ -253,7 +300,7 @@ static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) ...@@ -253,7 +300,7 @@ static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
padlock_reset_key(&ctx->cword.encrypt); padlock_reset_key(&ctx->cword.encrypt);
ts_state = irq_ts_save(); 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); irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.encrypt); padlock_store_cword(&ctx->cword.encrypt);
} }
...@@ -265,7 +312,7 @@ static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) ...@@ -265,7 +312,7 @@ static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
padlock_reset_key(&ctx->cword.encrypt); padlock_reset_key(&ctx->cword.encrypt);
ts_state = irq_ts_save(); 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); irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.encrypt); padlock_store_cword(&ctx->cword.encrypt);
} }
...@@ -482,8 +529,8 @@ static int __init padlock_init(void) ...@@ -482,8 +529,8 @@ static int __init padlock_init(void)
printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n"); printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n");
if (c->x86 == 6 && c->x86_model == 15 && c->x86_mask == 2) { if (c->x86 == 6 && c->x86_model == 15 && c->x86_mask == 2) {
ecb_fetch_blocks = 8; ecb_fetch_blocks = MAX_ECB_FETCH_BLOCKS;
cbc_fetch_blocks = 4; /* NOTE: notused */ cbc_fetch_blocks = MAX_CBC_FETCH_BLOCKS;
printk(KERN_NOTICE PFX "VIA Nano stepping 2 detected: enabling workaround.\n"); printk(KERN_NOTICE PFX "VIA Nano stepping 2 detected: enabling workaround.\n");
} }
......
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