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_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) || defined(__CORTEX_M23))
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 public:
00089     typedef void (T::*CCallbackSimple)(void);
00090     typedef void (T::*CCallback)(void *context);
00091 
00092     inline CThunk(T *instance)
00093     {
00094         init(instance, NULL, NULL);
00095     }
00096 
00097     inline CThunk(T *instance, CCallback callback)
00098     {
00099         init(instance, callback, NULL);
00100     }
00101 
00102     ~CThunk()
00103     {
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         CTHUNK_VARIABLES;
00179         volatile uint32_t instance;
00180         volatile uint32_t context;
00181         volatile uint32_t callback;
00182         volatile uint32_t trampoline;
00183     }  CThunkTrampoline;
00184 #else
00185     typedef struct {
00186         CTHUNK_VARIABLES;
00187         volatile uint32_t instance;
00188         volatile uint32_t context;
00189         volatile uint32_t callback;
00190         volatile uint32_t trampoline;
00191     } __attribute__((__packed__)) CThunkTrampoline;
00192 #endif
00193 
00194     static void trampoline(T *instance, void *context, CCallback *callback)
00195     {
00196         if (instance && *callback) {
00197             (static_cast<T *>(instance)->**callback)(context);
00198         }
00199     }
00200 
00201     volatile CThunkTrampoline m_thunk;
00202 
00203     inline void init(T *instance, CCallback callback, void *context)
00204     {
00205         /* remember callback - need to add this level of redirection
00206            as pointer size for member functions differs between platforms */
00207         m_callback = callback;
00208 
00209         /* populate thunking trampoline */
00210         CTHUNK_ASSIGMENT;
00211         m_thunk.context = (uint32_t)context;
00212         m_thunk.instance = (uint32_t)instance;
00213         m_thunk.callback = (uint32_t)&m_callback;
00214         m_thunk.trampoline = (uint32_t)&trampoline;
00215 
00216 #if defined(__CORTEX_A9)
00217         /* Data cache clean */
00218         /* Cache control */
00219         {
00220             uint32_t start_addr = (uint32_t)&m_thunk & 0xFFFFFFE0;
00221             uint32_t end_addr   = (uint32_t)&m_thunk + sizeof(m_thunk);
00222             uint32_t addr;
00223 
00224             /* Data cache clean and invalid */
00225             for (addr = start_addr; addr < end_addr; addr += 0x20) {
00226                 L1C_CleanInvalidateDCacheMVA((void *)addr);
00227             }
00228             /* Instruction cache invalid */
00229             L1C_InvalidateICacheAll();
00230             MMU_InvalidateTLB();
00231             L1C_InvalidateBTAC();
00232         }
00233 #endif
00234 #if defined(__CORTEX_M7)
00235         /* Data cache clean and invalid */
00236         SCB_CleanInvalidateDCache();
00237 
00238         /* Instruction cache invalid */
00239         SCB_InvalidateICache();
00240 #endif
00241         __ISB();
00242         __DSB();
00243     }
00244 };
00245 
00246 /**@}*/
00247 
00248 /**@}*/
00249 
00250 #endif/*__CTHUNK_H__*/
00251