1 #include <common.h> 2 #include <exports.h> 3 #include <linux/compiler.h> 4 5 #define FO(x) offsetof(struct jt_funcs, x) 6 7 #if defined(CONFIG_X86) 8 /* 9 * x86 does not have a dedicated register to store the pointer to 10 * the global_data. Thus the jump table address is stored in a 11 * global variable, but such approach does not allow for execution 12 * from flash memory. The global_data address is passed as argv[-1] 13 * to the application program. 14 */ 15 static struct jt_funcs *jt; 16 gd_t *global_data; 17 18 #define EXPORT_FUNC(f, a, x, ...) \ 19 asm volatile ( \ 20 " .globl " #x "\n" \ 21 #x ":\n" \ 22 " movl %0, %%eax\n" \ 23 " movl jt, %%ecx\n" \ 24 " jmp *(%%ecx, %%eax)\n" \ 25 : : "i"(FO(x)) : "eax", "ecx"); 26 #elif defined(CONFIG_PPC) 27 /* 28 * r2 holds the pointer to the global_data, r11 is a call-clobbered 29 * register 30 */ 31 #define EXPORT_FUNC(f, a, x, ...) \ 32 asm volatile ( \ 33 " .globl " #x "\n" \ 34 #x ":\n" \ 35 " lwz %%r11, %0(%%r2)\n" \ 36 " lwz %%r11, %1(%%r11)\n" \ 37 " mtctr %%r11\n" \ 38 " bctr\n" \ 39 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r11"); 40 #elif defined(CONFIG_ARM) 41 #ifdef CONFIG_ARM64 42 /* 43 * x18 holds the pointer to the global_data, x9 is a call-clobbered 44 * register 45 */ 46 #define EXPORT_FUNC(f, a, x, ...) \ 47 asm volatile ( \ 48 " .globl " #x "\n" \ 49 #x ":\n" \ 50 " ldr x9, [x18, %0]\n" \ 51 " ldr x9, [x9, %1]\n" \ 52 " br x9\n" \ 53 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "x9"); 54 #else 55 /* 56 * r9 holds the pointer to the global_data, ip is a call-clobbered 57 * register 58 */ 59 #define EXPORT_FUNC(f, a, x, ...) \ 60 asm volatile ( \ 61 " .globl " #x "\n" \ 62 #x ":\n" \ 63 " ldr ip, [r9, %0]\n" \ 64 " ldr pc, [ip, %1]\n" \ 65 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "ip"); 66 #endif 67 #elif defined(CONFIG_MIPS) 68 #ifdef CONFIG_CPU_MIPS64 69 /* 70 * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- 71 * clobbered register that is also used to set gp ($26). Note that the 72 * jr instruction also executes the instruction immediately following 73 * it; however, GCC/mips generates an additional `nop' after each asm 74 * statement 75 */ 76 #define EXPORT_FUNC(f, a, x, ...) \ 77 asm volatile ( \ 78 " .globl " #x "\n" \ 79 #x ":\n" \ 80 " ld $25, %0($26)\n" \ 81 " ld $25, %1($25)\n" \ 82 " jr $25\n" \ 83 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9"); 84 #else 85 /* 86 * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- 87 * clobbered register that is also used to set gp ($26). Note that the 88 * jr instruction also executes the instruction immediately following 89 * it; however, GCC/mips generates an additional `nop' after each asm 90 * statement 91 */ 92 #define EXPORT_FUNC(f, a, x, ...) \ 93 asm volatile ( \ 94 " .globl " #x "\n" \ 95 #x ":\n" \ 96 " lw $25, %0($26)\n" \ 97 " lw $25, %1($25)\n" \ 98 " jr $25\n" \ 99 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9"); 100 #endif 101 #elif defined(CONFIG_NIOS2) 102 /* 103 * gp holds the pointer to the global_data, r8 is call-clobbered 104 */ 105 #define EXPORT_FUNC(f, a, x, ...) \ 106 asm volatile ( \ 107 " .globl " #x "\n" \ 108 #x ":\n" \ 109 " movhi r8, %%hi(%0)\n" \ 110 " ori r8, r0, %%lo(%0)\n" \ 111 " add r8, r8, gp\n" \ 112 " ldw r8, 0(r8)\n" \ 113 " ldw r8, %1(r8)\n" \ 114 " jmp r8\n" \ 115 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "gp"); 116 #elif defined(CONFIG_M68K) 117 /* 118 * d7 holds the pointer to the global_data, a0 is a call-clobbered 119 * register 120 */ 121 #define EXPORT_FUNC(f, a, x, ...) \ 122 asm volatile ( \ 123 " .globl " #x "\n" \ 124 #x ":\n" \ 125 " move.l %%d7, %%a0\n" \ 126 " adda.l %0, %%a0\n" \ 127 " move.l (%%a0), %%a0\n" \ 128 " adda.l %1, %%a0\n" \ 129 " move.l (%%a0), %%a0\n" \ 130 " jmp (%%a0)\n" \ 131 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "a0"); 132 #elif defined(CONFIG_MICROBLAZE) 133 /* 134 * r31 holds the pointer to the global_data. r5 is a call-clobbered. 135 */ 136 #define EXPORT_FUNC(f, a, x, ...) \ 137 asm volatile ( \ 138 " .globl " #x "\n" \ 139 #x ":\n" \ 140 " lwi r5, r31, %0\n" \ 141 " lwi r5, r5, %1\n" \ 142 " bra r5\n" \ 143 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r5"); 144 #elif defined(CONFIG_BLACKFIN) 145 /* 146 * P3 holds the pointer to the global_data, P0 is a call-clobbered 147 * register 148 */ 149 #define EXPORT_FUNC(f, a, x, ...) \ 150 asm volatile ( \ 151 " .globl _" #x "\n_" \ 152 #x ":\n" \ 153 " P0 = [P3 + %0]\n" \ 154 " P0 = [P0 + %1]\n" \ 155 " JUMP (P0)\n" \ 156 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "P0"); 157 #elif defined(CONFIG_AVR32) 158 /* 159 * r6 holds the pointer to the global_data. r8 is call clobbered. 160 */ 161 #define EXPORT_FUNC(f, a, x, ...) \ 162 asm volatile( \ 163 " .globl\t" #x "\n" \ 164 #x ":\n" \ 165 " ld.w r8, r6[%0]\n" \ 166 " ld.w pc, r8[%1]\n" \ 167 : \ 168 : "i"(offsetof(gd_t, jt)), "i"(FO(x)) \ 169 : "r8"); 170 #elif defined(CONFIG_SH) 171 /* 172 * r13 holds the pointer to the global_data. r1 is a call clobbered. 173 */ 174 #define EXPORT_FUNC(f, a, x, ...) \ 175 asm volatile ( \ 176 " .align 2\n" \ 177 " .globl " #x "\n" \ 178 #x ":\n" \ 179 " mov r13, r1\n" \ 180 " add %0, r1\n" \ 181 " mov.l @r1, r2\n" \ 182 " add %1, r2\n" \ 183 " mov.l @r2, r1\n" \ 184 " jmp @r1\n" \ 185 " nop\n" \ 186 " nop\n" \ 187 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r1", "r2"); 188 #elif defined(CONFIG_SPARC) 189 /* 190 * g7 holds the pointer to the global_data. g1 is call clobbered. 191 */ 192 #define EXPORT_FUNC(f, a, x, ...) \ 193 asm volatile( \ 194 " .globl\t" #x "\n" \ 195 #x ":\n" \ 196 " set %0, %%g1\n" \ 197 " or %%g1, %%g7, %%g1\n" \ 198 " ld [%%g1], %%g1\n" \ 199 " ld [%%g1 + %1], %%g1\n" \ 200 " jmp %%g1\n" \ 201 " nop\n" \ 202 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "g1"); 203 #elif defined(CONFIG_NDS32) 204 /* 205 * r16 holds the pointer to the global_data. gp is call clobbered. 206 * not support reduced register (16 GPR). 207 */ 208 #define EXPORT_FUNC(f, a, x, ...) \ 209 asm volatile ( \ 210 " .globl " #x "\n" \ 211 #x ":\n" \ 212 " lwi $r16, [$gp + (%0)]\n" \ 213 " lwi $r16, [$r16 + (%1)]\n" \ 214 " jr $r16\n" \ 215 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "$r16"); 216 #elif defined(CONFIG_OPENRISC) 217 /* 218 * r10 holds the pointer to the global_data, r13 is a call-clobbered 219 * register 220 */ 221 #define EXPORT_FUNC(f, a, x, ...) \ 222 asm volatile ( \ 223 " .globl " #x "\n" \ 224 #x ":\n" \ 225 " l.lwz r13, %0(r10)\n" \ 226 " l.lwz r13, %1(r13)\n" \ 227 " l.jr r13\n" \ 228 " l.nop\n" \ 229 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r13"); 230 #elif defined(CONFIG_ARC) 231 /* 232 * r25 holds the pointer to the global_data. r10 is call clobbered. 233 */ 234 #define EXPORT_FUNC(f, a, x, ...) \ 235 asm volatile( \ 236 " .align 4\n" \ 237 " .globl " #x "\n" \ 238 #x ":\n" \ 239 " ld r10, [r25, %0]\n" \ 240 " ld r10, [r10, %1]\n" \ 241 " j [r10]\n" \ 242 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r10"); 243 #else 244 /*" addi $sp, $sp, -24\n" \ 245 " br $r16\n" \*/ 246 247 #error stubs definition missing for this architecture 248 #endif 249 250 /* This function is necessary to prevent the compiler from 251 * generating prologue/epilogue, preparing stack frame etc. 252 * The stub functions are special, they do not use the stack 253 * frame passed to them, but pass it intact to the actual 254 * implementation. On the other hand, asm() statements with 255 * arguments can be used only inside the functions (gcc limitation) 256 */ 257 #if GCC_VERSION < 30400 258 static 259 #endif /* GCC_VERSION */ 260 void __attribute__((unused)) dummy(void) 261 { 262 #include <_exports.h> 263 } 264 265 #include <asm/sections.h> 266 267 void app_startup(char * const *argv) 268 { 269 char *cp = __bss_start; 270 271 /* Zero out BSS */ 272 while (cp < _end) 273 *cp++ = 0; 274 275 #if defined(CONFIG_X86) 276 /* x86 does not have a dedicated register for passing global_data */ 277 global_data = (gd_t *)argv[-1]; 278 jt = global_data->jt; 279 #endif 280 } 281 282 #undef EXPORT_FUNC 283