Diff: platform/CThunk.h

Revision:

149:156823d33999

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/platform/CThunk.h	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,245 @@
+
+/** \addtogroup platform */
+/** @{*/
+/* General C++ Object Thunking class
+ *
+ * - allows direct callbacks to non-static C++ class functions
+ * - keeps track for the corresponding class instance
+ * - supports an optional context parameter for the called function
+ * - ideally suited for class object receiving interrupts (NVIC_SetVector)
+ *
+ * Copyright (c) 2014-2015 ARM Limited
+ *
+ * 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.
+ */
+
+/* General C++ Object Thunking class
+ *
+ * - allows direct callbacks to non-static C++ class functions
+ * - keeps track for the corresponding class instance
+ * - supports an optional context parameter for the called function
+ * - ideally suited for class object receiving interrupts (NVIC_SetVector)
+ */
+
+#ifndef __CTHUNK_H__
+#define __CTHUNK_H__
+
+#define CTHUNK_ADDRESS 1
+#define CTHUNK_VARIABLES volatile uint32_t code[2]
+
+#if (defined(__CORTEX_M3) || defined(__CORTEX_M4) || defined(__CORTEX_M7) || defined(__CORTEX_A9))
+/**
+* CTHUNK disassembly for Cortex-M3/M4/M7/A9 (thumb2):
+* * adr  r0, #4
+* * ldm  r0, {r0, r1, r2, pc}
+*
+* This instruction loads the arguments for the static thunking function to r0-r2, and
+* branches to that function by loading its address into PC.
+*
+* This is safe for both regular calling and interrupt calling, since it only touches scratch registers
+* which should be saved by the caller, and are automatically saved as part of the IRQ context switch.
+*/
+#define CTHUNK_ASSIGMENT do {                              \
+                             m_thunk.code[0] = 0xE890A001; \
+                             m_thunk.code[1] = 0x00008007; \
+                         } while (0)
+
+#elif (defined(__CORTEX_M0PLUS) || defined(__CORTEX_M0))
+/*
+* CTHUNK disassembly for Cortex M0/M0+ (thumb):
+* * adr  r0, #4
+* * ldm  r0, {r0, r1, r2, r3}
+* * bx   r3
+*/
+#define CTHUNK_ASSIGMENT do {                              \
+                             m_thunk.code[0] = 0xC80FA001; \
+                             m_thunk.code[1] = 0x00004718; \
+                         } while (0)
+
+#else
+#error "Target is not currently suported."
+#endif
+
+/* IRQ/Exception compatible thunk entry function */
+typedef void (*CThunkEntry)(void);
+
+/**
+ * Class for created a pointer with data bound to it
+ *
+ * @Note Synchronization level: Not protected
+ */
+template<class T>
+class CThunk
+{
+    public:
+        typedef void (T::*CCallbackSimple)(void);
+        typedef void (T::*CCallback)(void* context);
+
+        inline CThunk(T *instance)
+        {
+            init(instance, NULL, NULL);
+        }
+
+        inline CThunk(T *instance, CCallback callback)
+        {
+            init(instance, callback, NULL);
+        }
+
+        ~CThunk() {
+
+        }
+
+        inline CThunk(T *instance, CCallbackSimple callback)
+        {
+            init(instance, (CCallback)callback, NULL);
+        }
+
+        inline CThunk(T &instance, CCallback callback)
+        {
+            init(instance, callback, NULL);
+        }
+
+        inline CThunk(T &instance, CCallbackSimple callback)
+        {
+            init(instance, (CCallback)callback, NULL);
+        }
+
+        inline CThunk(T &instance, CCallback callback, void* context)
+        {
+            init(instance, callback, context);
+        }
+
+        inline void callback(CCallback callback)
+        {
+            m_callback = callback;
+        }
+
+        inline void callback(CCallbackSimple callback)
+        {
+            m_callback = (CCallback)callback;
+        }
+
+        inline void context(void* context)
+        {
+            m_thunk.context = (uint32_t)context;
+        }
+
+        inline void context(uint32_t context)
+        {
+            m_thunk.context = context;
+        }
+        
+        inline uint32_t entry(void)
+        {
+            return (((uint32_t)&m_thunk)|CTHUNK_ADDRESS);
+        }
+
+        /* get thunk entry point for connecting rhunk to an IRQ table */
+        inline operator CThunkEntry(void)
+        {
+            return (CThunkEntry)entry();
+        }
+
+        /* get thunk entry point for connecting rhunk to an IRQ table */
+        inline operator uint32_t(void)
+        {
+            return entry();
+        }
+
+        /* simple test function */
+        inline void call(void)
+        {
+            (((CThunkEntry)(entry()))());
+        }
+
+    private:
+        T* m_instance;
+        volatile CCallback m_callback;
+
+// TODO: this needs proper fix, to refactor toolchain header file and all its use
+// PACKED there is not defined properly for IAR
+#if defined (__ICCARM__)
+        typedef __packed struct
+        {
+            CTHUNK_VARIABLES;
+            volatile uint32_t instance;
+            volatile uint32_t context;
+            volatile uint32_t callback;
+            volatile uint32_t trampoline;
+        }  CThunkTrampoline;
+#else
+        typedef struct
+        {
+            CTHUNK_VARIABLES;
+            volatile uint32_t instance;
+            volatile uint32_t context;
+            volatile uint32_t callback;
+            volatile uint32_t trampoline;
+        } __attribute__((__packed__)) CThunkTrampoline;
+#endif
+
+        static void trampoline(T* instance, void* context, CCallback* callback)
+        {
+            if(instance && *callback) {
+                (static_cast<T*>(instance)->**callback)(context);
+            }
+        }
+
+        volatile CThunkTrampoline m_thunk;
+
+        inline void init(T *instance, CCallback callback, void* context)
+        {
+            /* remember callback - need to add this level of redirection
+               as pointer size for member functions differs between platforms */
+            m_callback = callback;
+
+            /* populate thunking trampoline */
+            CTHUNK_ASSIGMENT;
+            m_thunk.context = (uint32_t)context;
+            m_thunk.instance = (uint32_t)instance;
+            m_thunk.callback = (uint32_t)&m_callback;
+            m_thunk.trampoline = (uint32_t)&trampoline;
+
+#if defined(__CORTEX_A9)
+            /* Data cache clean */
+            /* Cache control */
+            {
+                uint32_t start_addr = (uint32_t)&m_thunk & 0xFFFFFFE0;
+                uint32_t end_addr   = (uint32_t)&m_thunk + sizeof(m_thunk);
+                uint32_t addr;
+                
+                /* Data cache clean and invalid */
+                for (addr = start_addr; addr < end_addr; addr += 0x20) {
+                    __v7_clean_inv_dcache_mva((void *)addr);
+                }
+                /* Instruction cache invalid */
+                __v7_inv_icache_all();
+                __ca9u_inv_tlb_all();
+                __v7_inv_btac();
+            }
+#endif
+#if defined(__CORTEX_M7)
+            /* Data cache clean and invalid */
+            SCB_CleanInvalidateDCache();
+
+            /* Instruction cache invalid */
+            SCB_InvalidateICache();
+#endif
+            __ISB();
+            __DSB();
+        }
+};
+
+#endif/*__CTHUNK_H__*/
+
+/** @}*/