CThunk.h

00001 
00002 /** \addtogroup platform */
00003 /** @{*/
00004 /**
00005  * \defgroup platform_CThunk CThunk class
00006  * @{
00007  */
00008 /* General C++ Object Thunking class
00009  *
00010  * - allows direct callbacks to non-static C++ class functions
00011  * - keeps track for the corresponding class instance
00012  * - supports an optional context parameter for the called function
00013  * - ideally suited for class object receiving interrupts (NVIC_SetVector)
00014  *
00015  * Copyright (c) 2014-2015 ARM Limited
00016  *
00017  * Licensed under the Apache License, Version 2.0 (the "License");
00018  * you may not use this file except in compliance with the License.
00019  * You may obtain a copy of the License at
00020  *
00021  *     http://www.apache.org/licenses/LICENSE-2.0
00022  *
00023  * Unless required by applicable law or agreed to in writing, software
00024  * distributed under the License is distributed on an "AS IS" BASIS,
00025  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00026  * See the License for the specific language governing permissions and
00027  * limitations under the License.
00028  */
00029 
00030 /* General C++ Object Thunking class
00031  *
00032  * - allows direct callbacks to non-static C++ class functions
00033  * - keeps track for the corresponding class instance
00034  * - supports an optional context parameter for the called function
00035  * - ideally suited for class object receiving interrupts (NVIC_SetVector)
00036  */
00037 
00038 #ifndef __CTHUNK_H__
00039 #define __CTHUNK_H__
00040 
00041 #define CTHUNK_ADDRESS 1
00042 #define CTHUNK_VARIABLES volatile uint32_t code[2]
00043 
00044 #if (defined(__CORTEX_M3) || defined(__CORTEX_M4) || defined(__CORTEX_M7) || defined(__CORTEX_A9) \
00045     || defined(__CORTEX_M23) || defined(__CORTEX_M33))
00046 /**
00047 * CTHUNK disassembly for Cortex-M3/M4/M7/A9 (thumb2):
00048 * * adr  r0, #4
00049 * * ldm  r0, {r0, r1, r2, pc}
00050 *
00051 * This instruction loads the arguments for the static thunking function to r0-r2, and
00052 * branches to that function by loading its address into PC.
00053 *
00054 * This is safe for both regular calling and interrupt calling, since it only touches scratch registers
00055 * which should be saved by the caller, and are automatically saved as part of the IRQ context switch.
00056 */
00057 #define CTHUNK_ASSIGMENT do {                              \
00058                              m_thunk.code[0] = 0xE890A001; \
00059                              m_thunk.code[1] = 0x00008007; \
00060                          } while (0)
00061 
00062 #elif (defined(__CORTEX_M0PLUS) || defined(__CORTEX_M0))
00063 /*
00064 * CTHUNK disassembly for Cortex M0/M0+ (thumb):
00065 * * adr  r0, #4
00066 * * ldm  r0, {r0, r1, r2, r3}
00067 * * bx   r3
00068 */
00069 #define CTHUNK_ASSIGMENT do {                              \
00070                              m_thunk.code[0] = 0xC80FA001; \
00071                              m_thunk.code[1] = 0x00004718; \
00072                          } while (0)
00073 
00074 #else
00075 #error "Target is not currently suported."
00076 #endif
00077 
00078 /* IRQ/Exception compatible thunk entry function */
00079 typedef void (*CThunkEntry)(void);
00080 
00081 /**
00082  * Class for created a pointer with data bound to it
00083  *
00084  * @note Synchronization level: Not protected
00085  */
00086 template<class T>
00087 class CThunk
00088 {
00089     public:
00090         typedef void (T::*CCallbackSimple)(void);
00091         typedef void (T::*CCallback)(void* context);
00092 
00093         inline CThunk(T *instance)
00094         {
00095             init(instance, NULL, NULL);
00096         }
00097 
00098         inline CThunk(T *instance, CCallback callback)
00099         {
00100             init(instance, callback, NULL);
00101         }
00102 
00103         ~CThunk() {
00104 
00105         }
00106 
00107         inline CThunk(T *instance, CCallbackSimple callback)
00108         {
00109             init(instance, (CCallback)callback, NULL);
00110         }
00111 
00112         inline CThunk(T &instance, CCallback callback)
00113         {
00114             init(instance, callback, NULL);
00115         }
00116 
00117         inline CThunk(T &instance, CCallbackSimple callback)
00118         {
00119             init(instance, (CCallback)callback, NULL);
00120         }
00121 
00122         inline CThunk(T &instance, CCallback callback, void* context)
00123         {
00124             init(instance, callback, context);
00125         }
00126 
00127         inline void callback(CCallback callback)
00128         {
00129             m_callback = callback;
00130         }
00131 
00132         inline void callback(CCallbackSimple callback)
00133         {
00134             m_callback = (CCallback)callback;
00135         }
00136 
00137         inline void context(void* context)
00138         {
00139             m_thunk.context = (uint32_t)context;
00140         }
00141 
00142         inline void context(uint32_t context)
00143         {
00144             m_thunk.context = context;
00145         }
00146         
00147         inline uint32_t entry(void)
00148         {
00149             return (((uint32_t)&m_thunk)|CTHUNK_ADDRESS);
00150         }
00151 
00152         /* get thunk entry point for connecting rhunk to an IRQ table */
00153         inline operator CThunkEntry(void)
00154         {
00155             return (CThunkEntry)entry();
00156         }
00157 
00158         /* get thunk entry point for connecting rhunk to an IRQ table */
00159         inline operator uint32_t(void)
00160         {
00161             return entry();
00162         }
00163 
00164         /* simple test function */
00165         inline void call(void)
00166         {
00167             (((CThunkEntry)(entry()))());
00168         }
00169 
00170     private:
00171         T* m_instance;
00172         volatile CCallback m_callback;
00173 
00174 // TODO: this needs proper fix, to refactor toolchain header file and all its use
00175 // PACKED there is not defined properly for IAR
00176 #if defined (__ICCARM__)
00177         typedef __packed struct
00178         {
00179             CTHUNK_VARIABLES;
00180             volatile uint32_t instance;
00181             volatile uint32_t context;
00182             volatile uint32_t callback;
00183             volatile uint32_t trampoline;
00184         }  CThunkTrampoline;
00185 #else
00186         typedef struct
00187         {
00188             CTHUNK_VARIABLES;
00189             volatile uint32_t instance;
00190             volatile uint32_t context;
00191             volatile uint32_t callback;
00192             volatile uint32_t trampoline;
00193         } __attribute__((__packed__)) CThunkTrampoline;
00194 #endif
00195 
00196         static void trampoline(T* instance, void* context, CCallback* callback)
00197         {
00198             if(instance && *callback) {
00199                 (static_cast<T*>(instance)->**callback)(context);
00200             }
00201         }
00202 
00203         volatile CThunkTrampoline m_thunk;
00204 
00205         inline void init(T *instance, CCallback callback, void* context)
00206         {
00207             /* remember callback - need to add this level of redirection
00208                as pointer size for member functions differs between platforms */
00209             m_callback = callback;
00210 
00211             /* populate thunking trampoline */
00212             CTHUNK_ASSIGMENT;
00213             m_thunk.context = (uint32_t)context;
00214             m_thunk.instance = (uint32_t)instance;
00215             m_thunk.callback = (uint32_t)&m_callback;
00216             m_thunk.trampoline = (uint32_t)&trampoline;
00217 
00218 #if defined(__CORTEX_A9)
00219             /* Data cache clean */
00220             /* Cache control */
00221             {
00222                 uint32_t start_addr = (uint32_t)&m_thunk & 0xFFFFFFE0;
00223                 uint32_t end_addr   = (uint32_t)&m_thunk + sizeof(m_thunk);
00224                 uint32_t addr;
00225 
00226                 /* Data cache clean and invalid */
00227                 for (addr = start_addr; addr < end_addr; addr += 0x20) {
00228                     L1C_CleanInvalidateDCacheMVA((void *)addr);
00229                 }
00230                 /* Instruction cache invalid */
00231                 L1C_InvalidateICacheAll();
00232                 MMU_InvalidateTLB();
00233                 L1C_InvalidateBTAC();
00234             }
00235 #endif
00236 #if defined(__CORTEX_M7)
00237             /* Data cache clean and invalid */
00238             SCB_CleanInvalidateDCache();
00239 
00240             /* Instruction cache invalid */
00241             SCB_InvalidateICache();
00242 #endif
00243             __ISB();
00244             __DSB();
00245         }
00246 };
00247 
00248 /**@}*/
00249 
00250 /**@}*/
00251 
00252 #endif/*__CTHUNK_H__*/
00253