[NUC472/M487] Add memory barrier for DMA transfer in AES/DES alter.

Author: ccli8

features/mbedtls/targets/TARGET_NUVOTON/TARGET_M480/aes/aes_alt.c

@@ -177,6 +177,14 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
     AES_SetDMATransfer(0, (uint32_t)pIn, (uint32_t)pOut, dataSize);
 
     g_AES_done = 0;
+    /* Ensure memory accesses above are completed before DMA is started
+     *
+     * Replacing __DSB() with __DMB() is also OK in this case.
+     *
+     * Refer to "multi-master systems" section with DMA in:
+     * https://static.docs.arm.com/dai0321/a/DAI0321A_programming_guide_memory_barriers_for_m_profile.pdf
+     */
+    __DSB();
     AES_Start(0, CRYPTO_DMA_ONE_SHOT);
     while (!g_AES_done);
 

features/mbedtls/targets/TARGET_NUVOTON/TARGET_M480/des/des_alt.c

@@ -407,6 +407,14 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
 
         TDES_SetDMATransfer(0, (uint32_t) dmabuf_in, (uint32_t) dmabuf_out, data_len);
 
+        /* Ensure memory accesses above are completed before DMA is started
+         *
+         * Replacing __DSB() with __DMB() is also OK in this case.
+         *
+         * Refer to "multi-master systems" section with DMA in:
+         * https://static.docs.arm.com/dai0321/a/DAI0321A_programming_guide_memory_barriers_for_m_profile.pdf
+         */
+        __DSB();
         /* Start enc/dec */
         TDES_Start(0, CRYPTO_DMA_ONE_SHOT);
         while (CRPT->TDES_STS & CRPT_TDES_STS_BUSY_Msk);

features/mbedtls/targets/TARGET_NUVOTON/TARGET_NUC472/aes/aes_alt.c

@@ -177,6 +177,14 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
     AES_SetDMATransfer(0, (uint32_t)pIn, (uint32_t)pOut, dataSize);
 
     g_AES_done = 0;
+    /* Ensure memory accesses above are completed before DMA is started
+     *
+     * Replacing __DSB() with __DMB() is also OK in this case.
+     *
+     * Refer to "multi-master systems" section with DMA in:
+     * https://static.docs.arm.com/dai0321/a/DAI0321A_programming_guide_memory_barriers_for_m_profile.pdf
+     */
+    __DSB();
     AES_Start(0, CRYPTO_DMA_ONE_SHOT);
     while (!g_AES_done);
 

features/mbedtls/targets/TARGET_NUVOTON/TARGET_NUC472/des/des_alt.c

@@ -407,6 +407,14 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
 
         TDES_SetDMATransfer(0, (uint32_t) dmabuf_in, (uint32_t) dmabuf_out, data_len);
 
+        /* Ensure memory accesses above are completed before DMA is started
+         *
+         * Replacing __DSB() with __DMB() is also OK in this case.
+         *
+         * Refer to "multi-master systems" section with DMA in:
+         * https://static.docs.arm.com/dai0321/a/DAI0321A_programming_guide_memory_barriers_for_m_profile.pdf
+         */
+        __DSB();
         /* Start enc/dec */
         TDES_Start(0, CRYPTO_DMA_ONE_SHOT);
         while (CRPT->TDES_STS & CRPT_TDES_STS_BUSY_Msk);