[NUC472/M487] Coordinate crypto init among AES/DES/SHA/PRNG

Add counter to track crypto init among crypto sub-modules. It includes:
1. Enable crypto clock
2. Enable crypto interrupt

As counter gets zero, crypto clock is disabled to save power.

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

@@ -34,8 +34,7 @@
 #include "mbed_assert.h"
 #include "mbed_error.h"
 #include "nu_bitutil.h"
-
-
+#include "crypto-misc.h"
 
 /* Implementation that should never be optimized out by the compiler */
 static void mbedtls_zeroize( void *v, size_t n )
@@ -69,15 +68,6 @@ static bool aes_dma_buff_compat(const void *buff, unsigned buff_size)
 void mbedtls_aes_init( mbedtls_aes_context *ctx )
 {
     memset( ctx, 0, sizeof( mbedtls_aes_context ) );
-
-    /* Unlock protected registers */
-    SYS_UnlockReg();
-    CLK_EnableModuleClock(CRPT_MODULE);
-    /* Lock protected registers */
-    SYS_LockReg();
-
-    NVIC_EnableIRQ(CRPT_IRQn);
-    AES_ENABLE_INT();
 }
 
 void mbedtls_aes_free( mbedtls_aes_context *ctx )
@@ -153,6 +143,11 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
         error("Buffer for AES alter. DMA requires to be word-aligned and located in 0x20000000-0x2FFFFFFF region.");
     }
 
+    /* Init crypto module */
+    crypto_init();
+    /* Enable AES interrupt */
+    AES_ENABLE_INT();
+    
     /* We support multiple contexts with context save & restore and so needs just one 
      * H/W channel. Always use H/W channel #0. */
 
@@ -195,6 +190,11 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
     ctx->iv[1] = CRPT->AES_FDBCK[1];
     ctx->iv[2] = CRPT->AES_FDBCK[2];
     ctx->iv[3] = CRPT->AES_FDBCK[3];
+    
+    /* Disable AES interrupt */
+    AES_DISABLE_INT();
+    /* Uninit crypto module */
+    crypto_uninit();
 }
 
 /*

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

@@ -17,21 +17,62 @@
 
 #include "cmsis.h"
 #include "mbed_assert.h"
+#include "mbed_critical.h"
+#include "mbed_error.h"
+#include <limits.h>
 #include "nu_modutil.h"
 #include "nu_bitutil.h"
 #include "crypto-misc.h"
 
-static int crypto_inited = 0;
 static int crypto_sha_avail = 1;
 
+/* Crypto (AES, DES, SHA, etc.) init counter. Crypto's keeps active as it is non-zero. */
+static uint16_t crypto_init_counter = 0U;
+
+/* As crypto init counter changes from 0 to 1:
+ *
+ * 1. Enable crypto clock
+ * 2. Enable crypto interrupt
+ */
 void crypto_init(void)
 {
-    if (crypto_inited) {
-        return;
+    core_util_critical_section_enter();
+    if (crypto_init_counter == USHRT_MAX) {
+        core_util_critical_section_exit();
+        error("Crypto clock enable counter would overflow (> USHRT_MAX)");
     }
-    crypto_inited = 1;
+    core_util_atomic_incr_u16(&crypto_init_counter, 1);
+    if (crypto_init_counter == 1) {
+        SYS_UnlockReg();    // Unlock protected register
+        CLK_EnableModuleClock(CRPT_MODULE);
+        SYS_LockReg();      // Lock protected register
         
-    CLK_EnableModuleClock(CRPT_MODULE);
+        NVIC_EnableIRQ(CRPT_IRQn);
+    }
+    core_util_critical_section_exit();
+}
+
+/* As crypto init counter changes from 1 to 0:
+ *
+ * 1. Disable crypto interrupt 
+ * 2. Disable crypto clock
+ */
+void crypto_uninit(void)
+{
+    core_util_critical_section_enter();
+    if (crypto_init_counter == 0) {
+        core_util_critical_section_exit();
+        error("Crypto clock enable counter would underflow (< 0)");
+    }
+    core_util_atomic_decr_u16(&crypto_init_counter, 1);
+    if (crypto_init_counter == 0) {
+        NVIC_DisableIRQ(CRPT_IRQn);
+        
+        SYS_UnlockReg();    // Unlock protected register
+        CLK_DisableModuleClock(CRPT_MODULE);
+        SYS_LockReg();      // Lock protected register
+    }
+    core_util_critical_section_exit();
 }
 
 /* Implementation that should never be optimized out by the compiler */

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

@@ -22,6 +22,7 @@ extern "C" {
 #endif
 
 void crypto_init(void);
+void crypto_uninit(void);
 void crypto_zeroize(void *v, size_t n);
 int crypto_sha_acquire(void);
 void crypto_sha_release(void);

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

@@ -49,7 +49,6 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
 
 void mbedtls_des_init(mbedtls_des_context *ctx)
 {
-    crypto_init();
     memset(ctx, 0, sizeof(mbedtls_des_context));
 }
 
@@ -64,7 +63,6 @@ void mbedtls_des_free( mbedtls_des_context *ctx )
 
 void mbedtls_des3_init( mbedtls_des3_context *ctx )
 {
-    crypto_init();
     memset(ctx, 0, sizeof(mbedtls_des3_context));
 }
 
@@ -329,6 +327,9 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
         error("Buffer for DES alter. DMA requires to be word-aligned and located in 0x20000000-0x2FFFFFFF region.");
     }
     
+    /* Init crypto module */
+    crypto_init();
+    
     // NOTE: Don't call driver function TDES_Open in BSP because it doesn't support TDES_CTL[3KEYS] setting.
     CRPT->TDES_CTL = (0 << CRPT_TDES_CTL_CHANNEL_Pos) | (enc << CRPT_TDES_CTL_ENCRPT_Pos) |
                      tdes_opmode | (TDES_IN_OUT_WHL_SWAP << CRPT_TDES_CTL_BLKSWAP_Pos);
@@ -418,6 +419,9 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
         }
     }
 
+    /* Uninit crypto module */
+    crypto_uninit();
+    
     return 0;
 }
 

features/mbedtls/targets/TARGET_NUVOTON/TARGET_M480/sha/sha_alt_hw.c

@@ -39,6 +39,7 @@ void crypto_sha_getinternstate(unsigned char output[], size_t olen);
 
 void mbedtls_sha1_hw_init(crypto_sha_context *ctx)
 {
+    /* Init crypto module */
     crypto_init();
     memset(ctx, 0, sizeof(crypto_sha_context));
 }
@@ -49,6 +50,8 @@ void mbedtls_sha1_hw_free(crypto_sha_context *ctx)
         return;
     }
 
+    /* Uninit crypto module */
+    crypto_uninit();
     crypto_zeroize(ctx, sizeof(crypto_sha_context));
 }
 
@@ -113,6 +116,7 @@ void mbedtls_sha1_hw_process(crypto_sha_context *ctx, const unsigned char data[6
 
 void mbedtls_sha256_hw_init(crypto_sha_context *ctx)
 {
+    /* Init crypto module */
     crypto_init();
     memset(ctx, 0, sizeof(crypto_sha_context));
 }
@@ -123,6 +127,8 @@ void mbedtls_sha256_hw_free(crypto_sha_context *ctx)
         return;
     }
 
+    /* Uninit crypto module */
+    crypto_uninit();
     crypto_zeroize(ctx, sizeof(crypto_sha_context));
 }
 
@@ -189,6 +195,7 @@ void mbedtls_sha256_hw_process(crypto_sha_context *ctx, const unsigned char data
 
 void mbedtls_sha512_hw_init(crypto_sha_context *ctx)
 {
+    /* Init crypto module */
     crypto_init();
     memset(ctx, 0, sizeof(crypto_sha_context));
 }
@@ -199,6 +206,8 @@ void mbedtls_sha512_hw_free(crypto_sha_context *ctx)
         return;
     }
 
+    /* Uninit crypto module */
+    crypto_uninit();
     crypto_zeroize(ctx, sizeof(crypto_sha_context));
 }
 

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

@@ -34,8 +34,7 @@
 #include "mbed_assert.h"
 #include "mbed_error.h"
 #include "nu_bitutil.h"
-
-
+#include "crypto-misc.h"
 
 /* Implementation that should never be optimized out by the compiler */
 static void mbedtls_zeroize( void *v, size_t n )
@@ -69,15 +68,6 @@ static bool aes_dma_buff_compat(const void *buff, unsigned buff_size)
 void mbedtls_aes_init( mbedtls_aes_context *ctx )
 {
     memset( ctx, 0, sizeof( mbedtls_aes_context ) );
-
-    /* Unlock protected registers */
-    SYS_UnlockReg();
-    CLK_EnableModuleClock(CRPT_MODULE);
-    /* Lock protected registers */
-    SYS_LockReg();
-
-    NVIC_EnableIRQ(CRPT_IRQn);
-    AES_ENABLE_INT();
 }
 
 void mbedtls_aes_free( mbedtls_aes_context *ctx )
@@ -153,6 +143,11 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
         error("Buffer for AES alter. DMA requires to be word-aligned and located in 0x20000000-0x2FFFFFFF region.");
     }
 
+    /* Init crypto module */
+    crypto_init();
+    /* Enable AES interrupt */
+    AES_ENABLE_INT();
+    
     /* We support multiple contexts with context save & restore and so needs just one 
      * H/W channel. Always use H/W channel #0. */
 
@@ -195,6 +190,11 @@ static void __nvt_aes_crypt( mbedtls_aes_context *ctx,
     ctx->iv[1] = CRPT->AES_FDBCK1;
     ctx->iv[2] = CRPT->AES_FDBCK2;
     ctx->iv[3] = CRPT->AES_FDBCK3;
+    
+    /* Disable AES interrupt */
+    AES_DISABLE_INT();
+    /* Uninit crypto module */
+    crypto_uninit();
 }
 
 /*

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

@@ -17,21 +17,62 @@
 
 #include "cmsis.h"
 #include "mbed_assert.h"
+#include "mbed_critical.h"
+#include "mbed_error.h"
+#include <limits.h>
 #include "nu_modutil.h"
 #include "nu_bitutil.h"
 #include "crypto-misc.h"
 
-static int crypto_inited = 0;
 static int crypto_sha_avail = 1;
 
+/* Crypto (AES, DES, SHA, etc.) init counter. Crypto's keeps active as it is non-zero. */
+static uint16_t crypto_init_counter = 0U;
+
+/* As crypto init counter changes from 0 to 1:
+ *
+ * 1. Enable crypto clock
+ * 2. Enable crypto interrupt
+ */
 void crypto_init(void)
 {
-    if (crypto_inited) {
-        return;
+    core_util_critical_section_enter();
+    if (crypto_init_counter == USHRT_MAX) {
+        core_util_critical_section_exit();
+        error("Crypto clock enable counter would overflow (> USHRT_MAX)");
     }
-    crypto_inited = 1;
+    core_util_atomic_incr_u16(&crypto_init_counter, 1);
+    if (crypto_init_counter == 1) {
+        SYS_UnlockReg();    // Unlock protected register
+        CLK_EnableModuleClock(CRPT_MODULE);
+        SYS_LockReg();      // Lock protected register
         
-    CLK_EnableModuleClock(CRPT_MODULE);
+        NVIC_EnableIRQ(CRPT_IRQn);
+    }
+    core_util_critical_section_exit();
+}
+
+/* As crypto init counter changes from 1 to 0:
+ *
+ * 1. Disable crypto interrupt 
+ * 2. Disable crypto clock
+ */
+void crypto_uninit(void)
+{
+    core_util_critical_section_enter();
+    if (crypto_init_counter == 0) {
+        core_util_critical_section_exit();
+        error("Crypto clock enable counter would underflow (< 0)");
+    }
+    core_util_atomic_decr_u16(&crypto_init_counter, 1);
+    if (crypto_init_counter == 0) {
+        NVIC_DisableIRQ(CRPT_IRQn);
+        
+        SYS_UnlockReg();    // Unlock protected register
+        CLK_DisableModuleClock(CRPT_MODULE);
+        SYS_LockReg();      // Lock protected register
+    }
+    core_util_critical_section_exit();
 }
 
 /* Implementation that should never be optimized out by the compiler */

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

@@ -22,6 +22,7 @@ extern "C" {
 #endif
 
 void crypto_init(void);
+void crypto_uninit(void);
 void crypto_zeroize(void *v, size_t n);
 int crypto_sha_acquire(void);
 void crypto_sha_release(void);

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

@@ -49,7 +49,6 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
 
 void mbedtls_des_init(mbedtls_des_context *ctx)
 {
-    crypto_init();
     memset(ctx, 0, sizeof(mbedtls_des_context));
 }
 
@@ -64,7 +63,6 @@ void mbedtls_des_free( mbedtls_des_context *ctx )
 
 void mbedtls_des3_init( mbedtls_des3_context *ctx )
 {
-    crypto_init();
     memset(ctx, 0, sizeof(mbedtls_des3_context));
 }
 
@@ -329,6 +327,9 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
         error("Buffer for DES alter. DMA requires to be word-aligned and located in 0x20000000-0x2FFFFFFF region.");
     }
     
+    /* Init crypto module */
+    crypto_init();
+    
     // NOTE: Don't call driver function TDES_Open in BSP because it doesn't support TDES_CTL[3KEYS] setting.
     CRPT->TDES_CTL = (0 << CRPT_TDES_CTL_CHANNEL_Pos) | (enc << CRPT_TDES_CTL_ENCRPT_Pos) |
                      tdes_opmode | (TDES_IN_OUT_WHL_SWAP << CRPT_TDES_CTL_BLKSWAP_Pos);
@@ -418,6 +419,9 @@ static int mbedtls_des_docrypt(uint16_t keyopt, uint8_t key[3][MBEDTLS_DES_KEY_S
         }
     }
 
+    /* Uninit crypto module */
+    crypto_uninit();
+    
     return 0;
 }
 

features/mbedtls/targets/TARGET_NUVOTON/TARGET_NUC472/sha/sha_alt_hw.c

@@ -39,6 +39,7 @@ void crypto_sha_getinternstate(unsigned char output[], size_t olen);
 
 void mbedtls_sha1_hw_init(crypto_sha_context *ctx)
 {
+    /* Init crypto module */
     crypto_init();
     memset(ctx, 0, sizeof(crypto_sha_context));
 }
@@ -49,6 +50,8 @@ void mbedtls_sha1_hw_free(crypto_sha_context *ctx)
         return;
     }
 
+    /* Uninit crypto module */
+    crypto_uninit();
     crypto_zeroize(ctx, sizeof(crypto_sha_context));
 }
 
@@ -113,6 +116,7 @@ void mbedtls_sha1_hw_process(crypto_sha_context *ctx, const unsigned char data[6
 
 void mbedtls_sha256_hw_init(crypto_sha_context *ctx)
 {
+    /* Init crypto module */
     crypto_init();
     memset(ctx, 0, sizeof(crypto_sha_context));
 }
@@ -123,6 +127,8 @@ void mbedtls_sha256_hw_free(crypto_sha_context *ctx)
         return;
     }
 
+    /* Uninit crypto module */
+    crypto_uninit();
     crypto_zeroize(ctx, sizeof(crypto_sha_context));
 }
 

targets/TARGET_NUVOTON/TARGET_M480/trng_api.c

@@ -21,6 +21,7 @@
 #include "cmsis.h"
 #include "us_ticker_api.h"
 #include "trng_api.h"
+#include "crypto-misc.h"
 
 /*
  * Get Random number generator.
@@ -63,23 +64,21 @@ static void trng_get(unsigned char *pConversionData)
 void trng_init(trng_t *obj)
 {
     (void)obj;
-    /* Unlock protected registers */
-    SYS_UnlockReg();
-    /* Enable IP clock */
-    CLK_EnableModuleClock(CRPT_MODULE);
     
-    /* Lock protected registers */
-    SYS_LockReg();
+    /* Init crypto module */
+    crypto_init();
     
-    NVIC_EnableIRQ(CRPT_IRQn);
     PRNG_ENABLE_INT();
 }
 
 void trng_free(trng_t *obj)
 {
     (void)obj;
+    
     PRNG_DISABLE_INT();
-    NVIC_DisableIRQ(CRPT_IRQn);
+    
+    /* Uninit crypto module */
+    crypto_uninit();
 }
 
 int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)

targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c

@@ -26,6 +26,7 @@
 #include "NUC472_442.h"
 #include "us_ticker_api.h"
 #include "trng_api.h"
+#include "crypto-misc.h"
 
 /*
  * Get Random number generator.
@@ -68,23 +69,21 @@ static void trng_get(unsigned char *pConversionData)
 void trng_init(trng_t *obj)
 {
     (void)obj;
-    /* Unlock protected registers */
-    SYS_UnlockReg();    
-    /* Enable IP clock */
-    CLK_EnableModuleClock(CRPT_MODULE);
     
-    /* Lock protected registers */
-    SYS_LockReg();
+    /* Init crypto module */
+    crypto_init();
     
-    NVIC_EnableIRQ(CRPT_IRQn);
     PRNG_ENABLE_INT();
 }
 
 void trng_free(trng_t *obj)
 {
     (void)obj;
+    
     PRNG_DISABLE_INT();
-    NVIC_DisableIRQ(CRPT_IRQn);
+    
+    /* Uninit crypto module */
+    crypto_uninit();
 }
 
 int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)