diff --git a/drivers/crypto/padlock-aes.c b/drivers/crypto/padlock-aes.c
index bf2917d197a018d13f1bc48ad4c93c0b0a93ccde..856b3cc2558387b7b239923c37c54f9d47b250ff 100644
--- a/drivers/crypto/padlock-aes.c
+++ b/drivers/crypto/padlock-aes.c
@@ -15,6 +15,8 @@
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
+#include <linux/percpu.h>
+#include <linux/smp.h>
 #include <asm/byteorder.h>
 #include <asm/i387.h>
 #include "padlock.h"
@@ -49,6 +51,8 @@ struct aes_ctx {
 	u32 *D;
 };
 
+static DEFINE_PER_CPU(struct cword *, last_cword);
+
 /* Tells whether the ACE is capable to generate
    the extended key for a given key_len. */
 static inline int
@@ -89,6 +93,7 @@ static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 	const __le32 *key = (const __le32 *)in_key;
 	u32 *flags = &tfm->crt_flags;
 	struct crypto_aes_ctx gen_aes;
+	int cpu;
 
 	if (key_len % 8) {
 		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
@@ -118,7 +123,7 @@ static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 
 	/* Don't generate extended keys if the hardware can do it. */
 	if (aes_hw_extkey_available(key_len))
-		return 0;
+		goto ok;
 
 	ctx->D = ctx->d_data;
 	ctx->cword.encrypt.keygen = 1;
@@ -131,15 +136,30 @@ static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 
 	memcpy(ctx->E, gen_aes.key_enc, AES_MAX_KEYLENGTH);
 	memcpy(ctx->D, gen_aes.key_dec, AES_MAX_KEYLENGTH);
+
+ok:
+	for_each_online_cpu(cpu)
+		if (&ctx->cword.encrypt == per_cpu(last_cword, cpu) ||
+		    &ctx->cword.decrypt == per_cpu(last_cword, cpu))
+			per_cpu(last_cword, cpu) = NULL;
+
 	return 0;
 }
 
 /* ====== Encryption/decryption routines ====== */
 
 /* These are the real call to PadLock. */
-static inline void padlock_reset_key(void)
+static inline void padlock_reset_key(struct cword *cword)
+{
+	int cpu = raw_smp_processor_id();
+
+	if (cword != per_cpu(last_cword, cpu))
+		asm volatile ("pushfl; popfl");
+}
+
+static inline void padlock_store_cword(struct cword *cword)
 {
-	asm volatile ("pushfl; popfl");
+	per_cpu(last_cword, raw_smp_processor_id()) = cword;
 }
 
 /*
@@ -149,7 +169,7 @@ static inline void padlock_reset_key(void)
  */
 
 static inline void padlock_xcrypt(const u8 *input, u8 *output, void *key,
-				  void *control_word)
+				  struct cword *control_word)
 {
 	asm volatile (".byte 0xf3,0x0f,0xa7,0xc8"	/* rep xcryptecb */
 		      : "+S"(input), "+D"(output)
@@ -213,22 +233,24 @@ static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {
 	struct aes_ctx *ctx = aes_ctx(tfm);
 	int ts_state;
-	padlock_reset_key();
 
+	padlock_reset_key(&ctx->cword.encrypt);
 	ts_state = irq_ts_save();
 	aes_crypt(in, out, ctx->E, &ctx->cword.encrypt);
 	irq_ts_restore(ts_state);
+	padlock_store_cword(&ctx->cword.encrypt);
 }
 
 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {
 	struct aes_ctx *ctx = aes_ctx(tfm);
 	int ts_state;
-	padlock_reset_key();
 
+	padlock_reset_key(&ctx->cword.encrypt);
 	ts_state = irq_ts_save();
 	aes_crypt(in, out, ctx->D, &ctx->cword.decrypt);
 	irq_ts_restore(ts_state);
+	padlock_store_cword(&ctx->cword.encrypt);
 }
 
 static struct crypto_alg aes_alg = {
@@ -261,7 +283,7 @@ static int ecb_aes_encrypt(struct blkcipher_desc *desc,
 	int err;
 	int ts_state;
 
-	padlock_reset_key();
+	padlock_reset_key(&ctx->cword.encrypt);
 
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
@@ -276,6 +298,8 @@ static int ecb_aes_encrypt(struct blkcipher_desc *desc,
 	}
 	irq_ts_restore(ts_state);
 
+	padlock_store_cword(&ctx->cword.encrypt);
+
 	return err;
 }
 
@@ -288,7 +312,7 @@ static int ecb_aes_decrypt(struct blkcipher_desc *desc,
 	int err;
 	int ts_state;
 
-	padlock_reset_key();
+	padlock_reset_key(&ctx->cword.decrypt);
 
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
@@ -302,6 +326,9 @@ static int ecb_aes_decrypt(struct blkcipher_desc *desc,
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
 	irq_ts_restore(ts_state);
+
+	padlock_store_cword(&ctx->cword.encrypt);
+
 	return err;
 }
 
@@ -336,7 +363,7 @@ static int cbc_aes_encrypt(struct blkcipher_desc *desc,
 	int err;
 	int ts_state;
 
-	padlock_reset_key();
+	padlock_reset_key(&ctx->cword.encrypt);
 
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
@@ -353,6 +380,8 @@ static int cbc_aes_encrypt(struct blkcipher_desc *desc,
 	}
 	irq_ts_restore(ts_state);
 
+	padlock_store_cword(&ctx->cword.decrypt);
+
 	return err;
 }
 
@@ -365,7 +394,7 @@ static int cbc_aes_decrypt(struct blkcipher_desc *desc,
 	int err;
 	int ts_state;
 
-	padlock_reset_key();
+	padlock_reset_key(&ctx->cword.encrypt);
 
 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);
@@ -380,6 +409,9 @@ static int cbc_aes_decrypt(struct blkcipher_desc *desc,
 	}
 
 	irq_ts_restore(ts_state);
+
+	padlock_store_cword(&ctx->cword.encrypt);
+
 	return err;
 }