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 /* 69 * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- 70 * clobbered register that is also used to set gp ($26). Note that the 71 * jr instruction also executes the instruction immediately following 72 * it; however, GCC/mips generates an additional `nop' after each asm 73 * statement 74 */ 75 #define EXPORT_FUNC(f, a, x, ...) \ 76 asm volatile ( \ 77 " .globl " #x "\n" \ 78 #x ":\n" \ 79 " lw $25, %0($26)\n" \ 80 " lw $25, %1($25)\n" \ 81 " jr $25\n" \ 82 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9"); 83 #elif defined(CONFIG_NIOS2) 84 /* 85 * gp holds the pointer to the global_data, r8 is call-clobbered 86 */ 87 #define EXPORT_FUNC(f, a, x, ...) \ 88 asm volatile ( \ 89 " .globl " #x "\n" \ 90 #x ":\n" \ 91 " movhi r8, %%hi(%0)\n" \ 92 " ori r8, r0, %%lo(%0)\n" \ 93 " add r8, r8, gp\n" \ 94 " ldw r8, 0(r8)\n" \ 95 " ldw r8, %1(r8)\n" \ 96 " jmp r8\n" \ 97 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "gp"); 98 #elif defined(CONFIG_M68K) 99 /* 100 * d7 holds the pointer to the global_data, a0 is a call-clobbered 101 * register 102 */ 103 #define EXPORT_FUNC(f, a, x, ...) \ 104 asm volatile ( \ 105 " .globl " #x "\n" \ 106 #x ":\n" \ 107 " move.l %%d7, %%a0\n" \ 108 " adda.l %0, %%a0\n" \ 109 " move.l (%%a0), %%a0\n" \ 110 " adda.l %1, %%a0\n" \ 111 " move.l (%%a0), %%a0\n" \ 112 " jmp (%%a0)\n" \ 113 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "a0"); 114 #elif defined(CONFIG_MICROBLAZE) 115 /* 116 * r31 holds the pointer to the global_data. r5 is a call-clobbered. 117 */ 118 #define EXPORT_FUNC(f, a, x, ...) \ 119 asm volatile ( \ 120 " .globl " #x "\n" \ 121 #x ":\n" \ 122 " lwi r5, r31, %0\n" \ 123 " lwi r5, r5, %1\n" \ 124 " bra r5\n" \ 125 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r5"); 126 #elif defined(CONFIG_BLACKFIN) 127 /* 128 * P3 holds the pointer to the global_data, P0 is a call-clobbered 129 * register 130 */ 131 #define EXPORT_FUNC(f, a, x, ...) \ 132 asm volatile ( \ 133 " .globl _" #x "\n_" \ 134 #x ":\n" \ 135 " P0 = [P3 + %0]\n" \ 136 " P0 = [P0 + %1]\n" \ 137 " JUMP (P0)\n" \ 138 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "P0"); 139 #elif defined(CONFIG_AVR32) 140 /* 141 * r6 holds the pointer to the global_data. r8 is call clobbered. 142 */ 143 #define EXPORT_FUNC(f, a, x, ...) \ 144 asm volatile( \ 145 " .globl\t" #x "\n" \ 146 #x ":\n" \ 147 " ld.w r8, r6[%0]\n" \ 148 " ld.w pc, r8[%1]\n" \ 149 : \ 150 : "i"(offsetof(gd_t, jt)), "i"(FO(x)) \ 151 : "r8"); 152 #elif defined(CONFIG_SH) 153 /* 154 * r13 holds the pointer to the global_data. r1 is a call clobbered. 155 */ 156 #define EXPORT_FUNC(f, a, x, ...) \ 157 asm volatile ( \ 158 " .align 2\n" \ 159 " .globl " #x "\n" \ 160 #x ":\n" \ 161 " mov r13, r1\n" \ 162 " add %0, r1\n" \ 163 " mov.l @r1, r2\n" \ 164 " add %1, r2\n" \ 165 " mov.l @r2, r1\n" \ 166 " jmp @r1\n" \ 167 " nop\n" \ 168 " nop\n" \ 169 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r1", "r2"); 170 #elif defined(CONFIG_SPARC) 171 /* 172 * g7 holds the pointer to the global_data. g1 is call clobbered. 173 */ 174 #define EXPORT_FUNC(f, a, x, ...) \ 175 asm volatile( \ 176 " .globl\t" #x "\n" \ 177 #x ":\n" \ 178 " set %0, %%g1\n" \ 179 " or %%g1, %%g7, %%g1\n" \ 180 " ld [%%g1], %%g1\n" \ 181 " ld [%%g1 + %1], %%g1\n" \ 182 " jmp %%g1\n" \ 183 " nop\n" \ 184 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "g1"); 185 #elif defined(CONFIG_NDS32) 186 /* 187 * r16 holds the pointer to the global_data. gp is call clobbered. 188 * not support reduced register (16 GPR). 189 */ 190 #define EXPORT_FUNC(f, a, x, ...) \ 191 asm volatile ( \ 192 " .globl " #x "\n" \ 193 #x ":\n" \ 194 " lwi $r16, [$gp + (%0)]\n" \ 195 " lwi $r16, [$r16 + (%1)]\n" \ 196 " jr $r16\n" \ 197 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "$r16"); 198 #elif defined(CONFIG_OPENRISC) 199 /* 200 * r10 holds the pointer to the global_data, r13 is a call-clobbered 201 * register 202 */ 203 #define EXPORT_FUNC(f, a, x, ...) \ 204 asm volatile ( \ 205 " .globl " #x "\n" \ 206 #x ":\n" \ 207 " l.lwz r13, %0(r10)\n" \ 208 " l.lwz r13, %1(r13)\n" \ 209 " l.jr r13\n" \ 210 " l.nop\n" \ 211 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r13"); 212 #elif defined(CONFIG_ARC) 213 /* 214 * r25 holds the pointer to the global_data. r10 is call clobbered. 215 */ 216 #define EXPORT_FUNC(f, a, x, ...) \ 217 asm volatile( \ 218 " .align 4\n" \ 219 " .globl " #x "\n" \ 220 #x ":\n" \ 221 " ld r10, [r25, %0]\n" \ 222 " ld r10, [r10, %1]\n" \ 223 " j [r10]\n" \ 224 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r10"); 225 #else 226 /*" addi $sp, $sp, -24\n" \ 227 " br $r16\n" \*/ 228 229 #error stubs definition missing for this architecture 230 #endif 231 232 /* This function is necessary to prevent the compiler from 233 * generating prologue/epilogue, preparing stack frame etc. 234 * The stub functions are special, they do not use the stack 235 * frame passed to them, but pass it intact to the actual 236 * implementation. On the other hand, asm() statements with 237 * arguments can be used only inside the functions (gcc limitation) 238 */ 239 #if GCC_VERSION < 30400 240 static 241 #endif /* GCC_VERSION */ 242 void __attribute__((unused)) dummy(void) 243 { 244 #include <_exports.h> 245 } 246 247 #include <asm/sections.h> 248 249 void app_startup(char * const *argv) 250 { 251 char *cp = __bss_start; 252 253 /* Zero out BSS */ 254 while (cp < _end) 255 *cp++ = 0; 256 257 #if defined(CONFIG_X86) 258 /* x86 does not have a dedicated register for passing global_data */ 259 global_data = (gd_t *)argv[-1]; 260 jt = global_data->jt; 261 #endif 262 } 263 264 #undef EXPORT_FUNC 265