CThunk.h

00001 
00002 /** \addtogroup platform */
00003 /** @{*/
00004 /* General C++ Object Thunking class
00005  *
00006  * - allows direct callbacks to non-static C++ class functions
00007  * - keeps track for the corresponding class instance
00008  * - supports an optional context parameter for the called function
00009  * - ideally suited for class object receiving interrupts (NVIC_SetVector)
00010  *
00011  * Copyright (c) 2014-2015 ARM Limited
00012  *
00013  * Licensed under the Apache License, Version 2.0 (the "License");
00014  * you may not use this file except in compliance with the License.
00015  * You may obtain a copy of the License at
00016  *
00017  *     http://www.apache.org/licenses/LICENSE-2.0
00018  *
00019  * Unless required by applicable law or agreed to in writing, software
00020  * distributed under the License is distributed on an "AS IS" BASIS,
00021  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00022  * See the License for the specific language governing permissions and
00023  * limitations under the License.
00024  */
00025 
00026 /* General C++ Object Thunking class
00027  *
00028  * - allows direct callbacks to non-static C++ class functions
00029  * - keeps track for the corresponding class instance
00030  * - supports an optional context parameter for the called function
00031  * - ideally suited for class object receiving interrupts (NVIC_SetVector)
00032  */
00033 
00034 #ifndef __CTHUNK_H__
00035 #define __CTHUNK_H__
00036 
00037 #define CTHUNK_ADDRESS 1
00038 #define CTHUNK_VARIABLES volatile uint32_t code[2]
00039 
00040 #if (defined(__CORTEX_M3) || defined(__CORTEX_M4) || defined(__CORTEX_M7) || defined(__CORTEX_A9))
00041 /**
00042 * CTHUNK disassembly for Cortex-M3/M4/M7/A9 (thumb2):
00043 * * adr  r0, #4
00044 * * ldm  r0, {r0, r1, r2, pc}
00045 *
00046 * This instruction loads the arguments for the static thunking function to r0-r2, and
00047 * branches to that function by loading its address into PC.
00048 *
00049 * This is safe for both regular calling and interrupt calling, since it only touches scratch registers
00050 * which should be saved by the caller, and are automatically saved as part of the IRQ context switch.
00051 */
00052 #define CTHUNK_ASSIGMENT do {                              \
00053                              m_thunk.code[0] = 0xE890A001; \
00054                              m_thunk.code[1] = 0x00008007; \
00055                          } while (0)
00056 
00057 #elif (defined(__CORTEX_M0PLUS) || defined(__CORTEX_M0))
00058 /*
00059 * CTHUNK disassembly for Cortex M0/M0+ (thumb):
00060 * * adr  r0, #4
00061 * * ldm  r0, {r0, r1, r2, r3}
00062 * * bx   r3
00063 */
00064 #define CTHUNK_ASSIGMENT do {                              \
00065                              m_thunk.code[0] = 0xC80FA001; \
00066                              m_thunk.code[1] = 0x00004718; \
00067                          } while (0)
00068 
00069 #else
00070 #error "Target is not currently suported."
00071 #endif
00072 
00073 /* IRQ/Exception compatible thunk entry function */
00074 typedef void (*CThunkEntry)(void);
00075 /** @}*/
00076 
00077 /**
00078  * Class for created a pointer with data bound to it
00079  *
00080  * @note Synchronization level: Not protected
00081  * @ingroup platform
00082  */
00083 template<class T>
00084 class CThunk
00085 {
00086     public:
00087         typedef void (T::*CCallbackSimple)(void);
00088         typedef void (T::*CCallback)(void* context);
00089 
00090         inline CThunk(T *instance)
00091         {
00092             init(instance, NULL, NULL);
00093         }
00094 
00095         inline CThunk(T *instance, CCallback callback)
00096         {
00097             init(instance, callback, NULL);
00098         }
00099 
00100         ~CThunk() {
00101 
00102         }
00103 
00104         inline CThunk(T *instance, CCallbackSimple callback)
00105         {
00106             init(instance, (CCallback)callback, NULL);
00107         }
00108 
00109         inline CThunk(T &instance, CCallback callback)
00110         {
00111             init(instance, callback, NULL);
00112         }
00113 
00114         inline CThunk(T &instance, CCallbackSimple callback)
00115         {
00116             init(instance, (CCallback)callback, NULL);
00117         }
00118 
00119         inline CThunk(T &instance, CCallback callback, void* context)
00120         {
00121             init(instance, callback, context);
00122         }
00123 
00124         inline void callback(CCallback callback)
00125         {
00126             m_callback = callback;
00127         }
00128 
00129         inline void callback(CCallbackSimple callback)
00130         {
00131             m_callback = (CCallback)callback;
00132         }
00133 
00134         inline void context(void* context)
00135         {
00136             m_thunk.context = (uint32_t)context;
00137         }
00138 
00139         inline void context(uint32_t context)
00140         {
00141             m_thunk.context = context;
00142         }
00143         
00144         inline uint32_t entry(void)
00145         {
00146             return (((uint32_t)&m_thunk)|CTHUNK_ADDRESS);
00147         }
00148 
00149         /* get thunk entry point for connecting rhunk to an IRQ table */
00150         inline operator CThunkEntry(void)
00151         {
00152             return (CThunkEntry)entry();
00153         }
00154 
00155         /* get thunk entry point for connecting rhunk to an IRQ table */
00156         inline operator uint32_t(void)
00157         {
00158             return entry();
00159         }
00160 
00161         /* simple test function */
00162         inline void call(void)
00163         {
00164             (((CThunkEntry)(entry()))());
00165         }
00166 
00167     private:
00168         T* m_instance;
00169         volatile CCallback m_callback;
00170 
00171 // TODO: this needs proper fix, to refactor toolchain header file and all its use
00172 // PACKED there is not defined properly for IAR
00173 #if defined (__ICCARM__)
00174         typedef __packed struct
00175         {
00176             CTHUNK_VARIABLES;
00177             volatile uint32_t instance;
00178             volatile uint32_t context;
00179             volatile uint32_t callback;
00180             volatile uint32_t trampoline;
00181         }  CThunkTrampoline;
00182 #else
00183         typedef struct
00184         {
00185             CTHUNK_VARIABLES;
00186             volatile uint32_t instance;
00187             volatile uint32_t context;
00188             volatile uint32_t callback;
00189             volatile uint32_t trampoline;
00190         } __attribute__((__packed__)) CThunkTrampoline;
00191 #endif
00192 
00193         static void trampoline(T* instance, void* context, CCallback* callback)
00194         {
00195             if(instance && *callback) {
00196                 (static_cast<T*>(instance)->**callback)(context);
00197             }
00198         }
00199 
00200         volatile CThunkTrampoline m_thunk;
00201 
00202         inline void init(T *instance, CCallback callback, void* context)
00203         {
00204             /* remember callback - need to add this level of redirection
00205                as pointer size for member functions differs between platforms */
00206             m_callback = callback;
00207 
00208             /* populate thunking trampoline */
00209             CTHUNK_ASSIGMENT;
00210             m_thunk.context = (uint32_t)context;
00211             m_thunk.instance = (uint32_t)instance;
00212             m_thunk.callback = (uint32_t)&m_callback;
00213             m_thunk.trampoline = (uint32_t)&trampoline;
00214 
00215 #if defined(__CORTEX_A9)
00216             /* Data cache clean */
00217             /* Cache control */
00218             {
00219                 uint32_t start_addr = (uint32_t)&m_thunk & 0xFFFFFFE0;
00220                 uint32_t end_addr   = (uint32_t)&m_thunk + sizeof(m_thunk);
00221                 uint32_t addr;
00222                 
00223                 /* Data cache clean and invalid */
00224                 for (addr = start_addr; addr < end_addr; addr += 0x20) {
00225                     __v7_clean_inv_dcache_mva((void *)addr);
00226                 }
00227                 /* Instruction cache invalid */
00228                 __v7_inv_icache_all();
00229                 __ca9u_inv_tlb_all();
00230                 __v7_inv_btac();
00231             }
00232 #endif
00233 #if defined(__CORTEX_M7)
00234             /* Data cache clean and invalid */
00235             SCB_CleanInvalidateDCache();
00236 
00237             /* Instruction cache invalid */
00238             SCB_InvalidateICache();
00239 #endif
00240             __ISB();
00241             __DSB();
00242         }
00243 };
00244 
00245 #endif/*__CTHUNK_H__*/
00246