[NUC472/M487] Fix DMA input/output buffers are overlapped in AES alter.

Author: ccli8

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

@@ -160,6 +160,7 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
     AES_Open(0, ctx->encDec, ctx->opMode, ctx->keySize, AES_IN_OUT_SWAP);
     AES_SetInitVect(0, ctx->iv);
     AES_SetKey(0, ctx->keys, ctx->keySize);
+    
     /* AES DMA buffer requirements same as above */
     if (! crypto_dma_buff_compat(input, dataSize, 16)) {
         memcpy(au8InputData, input, dataSize);
@@ -174,6 +175,14 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
         pOut = output;
     }
 
+    /* Even though AES H/W has limited support for overlapped DMA input/output buffers,
+     * we still seek to one backup buffer to make them non-overlapped for simplicity. */
+    if (crypto_dma_buffs_overlap(pIn, dataSize, pOut, dataSize)) {
+        memcpy(au8InputData, input, dataSize);
+        pIn = au8InputData;
+    }
+    MBED_ASSERT(! crypto_dma_buffs_overlap(pIn, dataSize, pOut, dataSize));
+    
     AES_SetDMATransfer(0, (uint32_t)pIn, (uint32_t)pOut, dataSize);
 
     crypto_aes_prestart();

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

@@ -407,6 +407,7 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
 
         memcpy(dmabuf_in, in_pos, data_len);
 
+        /* We always use DMA backup buffers, which are guaranteed to be non-overlapped. */
         TDES_SetDMATransfer(0, (uint32_t) dmabuf_in, (uint32_t) dmabuf_out, data_len);
 
         crypto_des_prestart();

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

@@ -160,6 +160,7 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
     AES_Open(0, ctx->encDec, ctx->opMode, ctx->keySize, AES_IN_OUT_SWAP);
     AES_SetInitVect(0, ctx->iv);
     AES_SetKey(0, ctx->keys, ctx->keySize);
+    
     /* AES DMA buffer requirements same as above */
     if (! crypto_dma_buff_compat(input, dataSize, 16)) {
         memcpy(au8InputData, input, dataSize);
@@ -174,6 +175,14 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
         pOut = output;
     }
 
+    /* Even though AES H/W has limited support for overlapped DMA input/output buffers,
+     * we still seek to one backup buffer to make them non-overlapped for simplicity. */
+    if (crypto_dma_buffs_overlap(pIn, dataSize, pOut, dataSize)) {
+        memcpy(au8InputData, input, dataSize);
+        pIn = au8InputData;
+    }
+    MBED_ASSERT(! crypto_dma_buffs_overlap(pIn, dataSize, pOut, dataSize));
+    
     AES_SetDMATransfer(0, (uint32_t)pIn, (uint32_t)pOut, dataSize);
 
     crypto_aes_prestart();

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

@@ -407,6 +407,7 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
 
         memcpy(dmabuf_in, in_pos, data_len);
 
+        /* We always use DMA backup buffers, which are guaranteed to be non-overlapped. */
         TDES_SetDMATransfer(0, (uint32_t) dmabuf_in, (uint32_t) dmabuf_out, data_len);
 
         crypto_des_prestart();

targets/TARGET_NUVOTON/TARGET_M480/crypto/crypto-misc.c

@@ -171,6 +171,38 @@ bool crypto_dma_buff_compat(const void *buff, size_t buff_size, size_t size_alig
         (((buff_ >> 28) == 0x2) && (buff_size <= (0x30000000 - buff_))));   /* 0x20000000-0x2FFFFFFF */
 }
 
+/* Overlap cases
+ *
+ * 1. in_buff in front of out_buff:
+ *
+ * in             in_end
+ * |              |
+ * ||||||||||||||||
+ *     ||||||||||||||||
+ *     |              |
+ *     out            out_end
+ *
+ * 2. out_buff in front of in_buff:
+ *
+ *     in             in_end
+ *     |              |
+ *     ||||||||||||||||
+ * ||||||||||||||||
+ * |              |
+ * out            out_end
+ */
+bool crypto_dma_buffs_overlap(const void *in_buff, size_t in_buff_size, const void *out_buff, size_t out_buff_size)
+{
+    uint32_t in = (uint32_t) in_buff;
+    uint32_t in_end = in + in_buff_size;
+    uint32_t out = (uint32_t) out_buff;
+    uint32_t out_end = out + out_buff_size;
+
+    bool overlap = (in <= out && out < in_end) || (out <= in && in < out_end);
+    
+    return overlap;
+}
+
 static bool crypto_submodule_acquire(uint16_t *submodule_avail)
 {
     uint16_t expectedCurrentValue = 1;

targets/TARGET_NUVOTON/TARGET_M480/crypto/crypto-misc.h

@@ -76,6 +76,9 @@ bool crypto_des_wait(void);
  */
 bool crypto_dma_buff_compat(const void *buff, size_t buff_size, size_t size_aligned_to);
 
+/* Check if input/output buffers are overlapped */
+bool crypto_dma_buffs_overlap(const void *in_buff, size_t in_buff_size, const void *out_buff, size_t out_buff_size);
+
 #ifdef __cplusplus
 }
 #endif

targets/TARGET_NUVOTON/TARGET_NUC472/crypto/crypto-misc.c

@@ -171,6 +171,38 @@ bool crypto_dma_buff_compat(const void *buff, size_t buff_size, size_t size_alig
         (((buff_ >> 28) == 0x2) && (buff_size <= (0x30000000 - buff_))));   /* 0x20000000-0x2FFFFFFF */
 }
 
+/* Overlap cases
+ *
+ * 1. in_buff in front of out_buff:
+ *
+ * in             in_end
+ * |              |
+ * ||||||||||||||||
+ *     ||||||||||||||||
+ *     |              |
+ *     out            out_end
+ *
+ * 2. out_buff in front of in_buff:
+ *
+ *     in             in_end
+ *     |              |
+ *     ||||||||||||||||
+ * ||||||||||||||||
+ * |              |
+ * out            out_end
+ */
+bool crypto_dma_buffs_overlap(const void *in_buff, size_t in_buff_size, const void *out_buff, size_t out_buff_size)
+{
+    uint32_t in = (uint32_t) in_buff;
+    uint32_t in_end = in + in_buff_size;
+    uint32_t out = (uint32_t) out_buff;
+    uint32_t out_end = out + out_buff_size;
+
+    bool overlap = (in <= out && out < in_end) || (out <= in && in < out_end);
+    
+    return overlap;
+}
+
 static bool crypto_submodule_acquire(uint16_t *submodule_avail)
 {
     uint16_t expectedCurrentValue = 1;

targets/TARGET_NUVOTON/TARGET_NUC472/crypto/crypto-misc.h

@@ -76,6 +76,9 @@ bool crypto_des_wait(void);
  */
 bool crypto_dma_buff_compat(const void *buff, size_t buff_size, size_t size_aligned_to);
 
+/* Check if input/output buffers are overlapped */
+bool crypto_dma_buffs_overlap(const void *in_buff, size_t in_buff_size, const void *out_buff, size_t out_buff_size);
+
 #ifdef __cplusplus
 }
 #endif