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From: Nicolas Toromanoff <nicolas.toromanoff@foss.st.com>
To: Herbert Xu <herbert@gondor.apana.org.au>,
	"David S . Miller" <davem@davemloft.net>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Marek Vasut <marex@denx.de>,
	Nicolas Toromanoff <nicolas.toromanoff@foss.st.com>,
	<linux-crypto@vger.kernel.org>,
	<linux-stm32@st-md-mailman.stormreply.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>
Subject: [PATCH 8/8] crypto: stm32/cryp - reorder hw initialization
Date: Fri, 29 Oct 2021 15:54:54 +0200	[thread overview]
Message-ID: <20211029135454.4383-9-nicolas.toromanoff@foss.st.com> (raw)
In-Reply-To: <20211029135454.4383-1-nicolas.toromanoff@foss.st.com>

The CRYP IP checks the written key depending of the configuration, it's
safer to write the whole configuration then the key to avoid unexpected
behavior.

Signed-off-by: Nicolas Toromanoff <nicolas.toromanoff@foss.st.com>
---
 drivers/crypto/stm32/stm32-cryp.c | 39 ++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/drivers/crypto/stm32/stm32-cryp.c b/drivers/crypto/stm32/stm32-cryp.c
index 54e19cbe35c9..25d0147012cb 100644
--- a/drivers/crypto/stm32/stm32-cryp.c
+++ b/drivers/crypto/stm32/stm32-cryp.c
@@ -232,6 +232,11 @@ static inline int stm32_cryp_wait_busy(struct stm32_cryp *cryp)
 			!(status & SR_BUSY), 10, 100000);
 }
 
+static inline void stm32_cryp_enable(struct stm32_cryp *cryp)
+{
+	writel_relaxed(readl_relaxed(cryp->regs + CRYP_CR) | CR_CRYPEN, cryp->regs + CRYP_CR);
+}
+
 static inline int stm32_cryp_wait_enable(struct stm32_cryp *cryp)
 {
 	u32 status;
@@ -534,9 +539,6 @@ static int stm32_cryp_hw_init(struct stm32_cryp *cryp)
 	/* Disable interrupt */
 	stm32_cryp_write(cryp, CRYP_IMSCR, 0);
 
-	/* Set key */
-	stm32_cryp_hw_write_key(cryp);
-
 	/* Set configuration */
 	cfg = CR_DATA8 | CR_FFLUSH;
 
@@ -562,23 +564,36 @@ static int stm32_cryp_hw_init(struct stm32_cryp *cryp)
 	/* AES ECB/CBC decrypt: run key preparation first */
 	if (is_decrypt(cryp) &&
 	    ((hw_mode == CR_AES_ECB) || (hw_mode == CR_AES_CBC))) {
-		stm32_cryp_write(cryp, CRYP_CR, cfg | CR_AES_KP | CR_CRYPEN);
+		/* Configure in key preparation mode */
+		stm32_cryp_write(cryp, CRYP_CR, cfg | CR_AES_KP);
 
+		/* Set key only after full configuration done */
+		stm32_cryp_hw_write_key(cryp);
+
+		/* Start prepare key */
+		stm32_cryp_enable(cryp);
 		/* Wait for end of processing */
 		ret = stm32_cryp_wait_busy(cryp);
 		if (ret) {
 			dev_err(cryp->dev, "Timeout (key preparation)\n");
 			return ret;
 		}
-	}
 
-	cfg |= hw_mode;
+		cfg |= hw_mode | CR_DEC_NOT_ENC;
 
-	if (is_decrypt(cryp))
-		cfg |= CR_DEC_NOT_ENC;
+		/* Apply updated config (Decrypt + algo) and flush */
+		stm32_cryp_write(cryp, CRYP_CR, cfg);
+	} else {
+		cfg |= hw_mode;
+		if (is_decrypt(cryp))
+			cfg |= CR_DEC_NOT_ENC;
 
-	/* Apply config and flush (valid when CRYPEN = 0) */
-	stm32_cryp_write(cryp, CRYP_CR, cfg);
+		/* Apply config and flush */
+		stm32_cryp_write(cryp, CRYP_CR, cfg);
+
+		/* Set key only after configuration done */
+		stm32_cryp_hw_write_key(cryp);
+	}
 
 	switch (hw_mode) {
 	case CR_AES_GCM:
@@ -606,9 +621,7 @@ static int stm32_cryp_hw_init(struct stm32_cryp *cryp)
 	}
 
 	/* Enable now */
-	cfg |= CR_CRYPEN;
-
-	stm32_cryp_write(cryp, CRYP_CR, cfg);
+	stm32_cryp_enable(cryp);
 
 	return 0;
 }
-- 
2.17.1


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      parent reply	other threads:[~2021-10-29 13:59 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-29 13:54 [PATCH 0/8] STM32 CRYP driver: many fixes Nicolas Toromanoff
2021-10-29 13:54 ` [PATCH 1/8] crypto: stm32/cryp - defer probe for reset controller Nicolas Toromanoff
2021-10-29 13:54 ` [PATCH 2/8] crypto: stm32/cryp - don't print error on probe deferral Nicolas Toromanoff
2021-10-29 13:54 ` [PATCH 3/8] crypto: stm32/cryp - fix CTR counter carry Nicolas Toromanoff
2021-10-31 12:28   ` Ard Biesheuvel
2021-11-02 11:12     ` Nicolas Toromanoff
2021-10-29 13:54 ` [PATCH 4/8] crypto: stm32/cryp - fix race condition Nicolas Toromanoff
2021-10-29 14:23   ` Marek Vasut
2021-10-29 15:21     ` Nicolas Toromanoff
2021-10-29 16:48       ` Marek Vasut
2021-10-29 13:54 ` [PATCH 5/8] crypto: stm32/cryp - check early input data Nicolas Toromanoff
2021-10-29 13:54 ` [PATCH 6/8] crypto: stm32/cryp - fix double pm exit Nicolas Toromanoff
2021-10-29 13:54 ` [PATCH 7/8] crypto: stm32/cryp - fix bugs and crash in tests Nicolas Toromanoff
2021-10-29 13:54 ` Nicolas Toromanoff [this message]

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