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

Revision:

180:96ed750bd169

Child:

182:a56a73fd2a6f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NUVOTON/TARGET_M480/crypto/crypto-misc.c	Wed Jan 17 15:23:54 2018 +0000
@@ -0,0 +1,255 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2015-2016 Nuvoton
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#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"
+
+/* Track if AES H/W is available */
+static uint16_t crypto_aes_avail = 1;
+/* Track if DES H/W is available */
+static uint16_t crypto_des_avail = 1;
+/* Track if SHA H/W is available */
+static uint16_t 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;
+
+static bool crypto_submodule_acquire(uint16_t *submodule_avail);
+static void crypto_submodule_release(uint16_t *submodule_avail);
+
+/* Track if PRNG H/W operation is done */
+static volatile uint16_t crypto_prng_done;
+/* Track if AES H/W operation is done */
+static volatile uint16_t crypto_aes_done;
+/* Track if DES H/W operation is done */
+static volatile uint16_t crypto_des_done;
+
+static void crypto_submodule_prestart(volatile uint16_t *submodule_done);
+static bool crypto_submodule_wait(volatile uint16_t *submodule_done);
+
+/* As crypto init counter changes from 0 to 1:
+ *
+ * 1. Enable crypto clock
+ * 2. Enable crypto interrupt
+ */
+void crypto_init(void)
+{
+    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)");
+    }
+    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
+        
+        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 */
+void crypto_zeroize(void *v, size_t n)
+{
+    volatile unsigned char *p = (unsigned char*) v;
+    while (n--) {
+        *p++ = 0;
+    }
+}
+
+bool crypto_aes_acquire(void)
+{
+    return crypto_submodule_acquire(&crypto_aes_avail);
+}
+
+void crypto_aes_release(void)
+{
+    crypto_submodule_release(&crypto_aes_avail);
+}
+
+bool crypto_des_acquire(void)
+{
+    return crypto_submodule_acquire(&crypto_des_avail);
+}
+
+void crypto_des_release(void)
+{
+    crypto_submodule_release(&crypto_des_avail);
+}
+
+bool crypto_sha_acquire(void)
+{
+    return crypto_submodule_acquire(&crypto_sha_avail);
+}
+
+void crypto_sha_release(void)
+{
+    crypto_submodule_release(&crypto_sha_avail);
+}
+
+void crypto_prng_prestart(void)
+{
+    crypto_submodule_prestart(&crypto_prng_done);
+}
+
+bool crypto_prng_wait(void)
+{
+    return crypto_submodule_wait(&crypto_prng_done);
+}
+
+void crypto_aes_prestart(void)
+{
+    crypto_submodule_prestart(&crypto_aes_done);
+}
+
+bool crypto_aes_wait(void)
+{
+    return crypto_submodule_wait(&crypto_aes_done);
+}
+
+void crypto_des_prestart(void)
+{
+    crypto_submodule_prestart(&crypto_des_done);
+}
+
+bool crypto_des_wait(void)
+{
+    return crypto_submodule_wait(&crypto_des_done);
+}
+
+bool crypto_dma_buff_compat(const void *buff, size_t buff_size, size_t size_aligned_to)
+{
+    uint32_t buff_ = (uint32_t) buff;
+
+    return (((buff_ & 0x03) == 0) &&                                        /* Word-aligned buffer base address */
+        ((buff_size & (size_aligned_to - 1)) == 0) &&                       /* Crypto submodule dependent buffer size alignment */
+        (((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;
+    return core_util_atomic_cas_u16(submodule_avail, &expectedCurrentValue, 0);
+}
+
+static void crypto_submodule_release(uint16_t *submodule_avail)
+{
+    uint16_t expectedCurrentValue = 0;
+    while (! core_util_atomic_cas_u16(submodule_avail, &expectedCurrentValue, 1));
+}
+
+static void crypto_submodule_prestart(volatile uint16_t *submodule_done)
+{
+    *submodule_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();
+}
+
+static bool crypto_submodule_wait(volatile uint16_t *submodule_done)
+{
+    while (! *submodule_done);
+
+    /* Ensure while loop above and subsequent code are not reordered */
+    __DSB();
+
+    return true;
+}
+
+/* Crypto interrupt handler */
+void CRYPTO_IRQHandler()
+{
+    if (PRNG_GET_INT_FLAG()) {
+        crypto_prng_done = 1;
+        PRNG_CLR_INT_FLAG();
+    }  else if (AES_GET_INT_FLAG()) {
+        crypto_aes_done = 1;
+        AES_CLR_INT_FLAG();
+    } else if (TDES_GET_INT_FLAG()) {
+        crypto_des_done = 1;
+        TDES_CLR_INT_FLAG();
+    }
+}