1#include <common.h> 2#include <exports.h> 3#include <linux/compiler.h> 4 5struct cmd_tbl; 6 7#define FO(x) offsetof(struct jt_funcs, x) 8 9#if defined(CONFIG_X86) 10/* 11 * x86 does not have a dedicated register to store the pointer to 12 * the global_data. Thus the jump table address is stored in a 13 * global variable, but such approach does not allow for execution 14 * from flash memory. The global_data address is passed as argv[-1] 15 * to the application program. 16 */ 17struct jt_funcs *jt; 18gd_t *global_data; 19 20#define EXPORT_FUNC(f, a, x, ...) \ 21 asm volatile ( \ 22" .globl " #x "\n" \ 23#x ":\n" \ 24" movl %0, %%eax\n" \ 25" movl jt, %%ecx\n" \ 26" jmp *(%%ecx, %%eax)\n" \ 27 : : "i"(FO(x)) : "eax", "ecx"); 28#elif defined(CONFIG_PPC) 29/* 30 * r2 holds the pointer to the global_data, r11 is a call-clobbered 31 * register 32 */ 33#define EXPORT_FUNC(f, a, x, ...) \ 34 asm volatile ( \ 35" .globl " #x "\n" \ 36#x ":\n" \ 37" lwz %%r11, %0(%%r2)\n" \ 38" lwz %%r11, %1(%%r11)\n" \ 39" mtctr %%r11\n" \ 40" bctr\n" \ 41 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r11"); 42#elif defined(CONFIG_ARM) 43#ifdef CONFIG_ARM64 44/* 45 * x18 holds the pointer to the global_data, x9 is a call-clobbered 46 * register 47 */ 48#define EXPORT_FUNC(f, a, x, ...) \ 49 asm volatile ( \ 50" .globl " #x "\n" \ 51#x ":\n" \ 52" ldr x9, [x18, %0]\n" \ 53" ldr x9, [x9, %1]\n" \ 54" br x9\n" \ 55 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "x9"); 56#else 57/* 58 * r9 holds the pointer to the global_data, ip is a call-clobbered 59 * register 60 */ 61#define EXPORT_FUNC(f, a, x, ...) \ 62 asm volatile ( \ 63" .globl " #x "\n" \ 64#x ":\n" \ 65" ldr ip, [r9, %0]\n" \ 66" ldr pc, [ip, %1]\n" \ 67 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "ip"); 68#endif 69#elif defined(CONFIG_MIPS) 70#ifdef CONFIG_CPU_MIPS64 71/* 72 * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- 73 * clobbered register that is also used to set gp ($26). Note that the 74 * jr instruction also executes the instruction immediately following 75 * it; however, GCC/mips generates an additional `nop' after each asm 76 * statement 77 */ 78#define EXPORT_FUNC(f, a, x, ...) \ 79 asm volatile ( \ 80" .globl " #x "\n" \ 81#x ":\n" \ 82" ld $25, %0($26)\n" \ 83" ld $25, %1($25)\n" \ 84" jr $25\n" \ 85 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9"); 86#else 87/* 88 * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- 89 * clobbered register that is also used to set gp ($26). Note that the 90 * jr instruction also executes the instruction immediately following 91 * it; however, GCC/mips generates an additional `nop' after each asm 92 * statement 93 */ 94#define EXPORT_FUNC(f, a, x, ...) \ 95 asm volatile ( \ 96" .globl " #x "\n" \ 97#x ":\n" \ 98" lw $25, %0($26)\n" \ 99" lw $25, %1($25)\n" \ 100" jr $25\n" \ 101 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9"); 102#endif 103#elif defined(CONFIG_NIOS2) 104/* 105 * gp holds the pointer to the global_data, r8 is call-clobbered 106 */ 107#define EXPORT_FUNC(f, a, x, ...) \ 108 asm volatile ( \ 109" .globl " #x "\n" \ 110#x ":\n" \ 111" movhi r8, %%hi(%0)\n" \ 112" ori r8, r0, %%lo(%0)\n" \ 113" add r8, r8, gp\n" \ 114" ldw r8, 0(r8)\n" \ 115" ldw r8, %1(r8)\n" \ 116" jmp r8\n" \ 117 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "gp"); 118#elif defined(CONFIG_M68K) 119/* 120 * d7 holds the pointer to the global_data, a0 is a call-clobbered 121 * register 122 */ 123#define EXPORT_FUNC(f, a, x, ...) \ 124 asm volatile ( \ 125" .globl " #x "\n" \ 126#x ":\n" \ 127" move.l %%d7, %%a0\n" \ 128" adda.l %0, %%a0\n" \ 129" move.l (%%a0), %%a0\n" \ 130" adda.l %1, %%a0\n" \ 131" move.l (%%a0), %%a0\n" \ 132" jmp (%%a0)\n" \ 133 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "a0"); 134#elif defined(CONFIG_MICROBLAZE) 135/* 136 * r31 holds the pointer to the global_data. r5 is a call-clobbered. 137 */ 138#define EXPORT_FUNC(f, a, x, ...) \ 139 asm volatile ( \ 140" .globl " #x "\n" \ 141#x ":\n" \ 142" lwi r5, r31, %0\n" \ 143" lwi r5, r5, %1\n" \ 144" bra r5\n" \ 145 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r5"); 146#elif defined(CONFIG_SH) 147/* 148 * r13 holds the pointer to the global_data. r1 is a call clobbered. 149 */ 150#define EXPORT_FUNC(f, a, x, ...) \ 151 asm volatile ( \ 152 " .align 2\n" \ 153 " .globl " #x "\n" \ 154 #x ":\n" \ 155 " mov r13, r1\n" \ 156 " add %0, r1\n" \ 157 " mov.l @r1, r2\n" \ 158 " add %1, r2\n" \ 159 " mov.l @r2, r1\n" \ 160 " jmp @r1\n" \ 161 " nop\n" \ 162 " nop\n" \ 163 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r1", "r2"); 164#elif defined(CONFIG_RISCV) 165/* 166 * gp holds the pointer to the global_data. t0 is call clobbered. 167 */ 168#ifdef CONFIG_ARCH_RV64I 169#define EXPORT_FUNC(f, a, x, ...) \ 170 asm volatile ( \ 171" .globl " #x "\n" \ 172#x ":\n" \ 173" ld t0, %0(gp)\n" \ 174" ld t0, %1(t0)\n" \ 175" jr t0\n" \ 176 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t0"); 177#else 178#define EXPORT_FUNC(f, a, x, ...) \ 179 asm volatile ( \ 180" .globl " #x "\n" \ 181#x ":\n" \ 182" lw t0, %0(gp)\n" \ 183" lw t0, %1(t0)\n" \ 184" jr t0\n" \ 185 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t0"); 186#endif 187#elif defined(CONFIG_ARC) 188/* 189 * r25 holds the pointer to the global_data. r10 is call clobbered. 190 */ 191#define EXPORT_FUNC(f, a, x, ...) \ 192 asm volatile( \ 193" .align 4\n" \ 194" .globl " #x "\n" \ 195#x ":\n" \ 196" ld r10, [r25, %0]\n" \ 197" ld r10, [r10, %1]\n" \ 198" j [r10]\n" \ 199 : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r10"); 200#elif defined(CONFIG_XTENSA) 201/* 202 * Global data ptr is in global_data, jump table ptr is in jt. 203 * Windowed ABI: Jump just past 'entry' in target and adjust stack frame 204 * (extract stack frame size from target 'entry' instruction). 205 */ 206 207static void **jt; 208 209#if defined(__XTENSA_CALL0_ABI__) 210#define EXPORT_FUNC(f, a, x, ...) \ 211 asm volatile ( \ 212" .extern jt\n" \ 213" .globl " #x "\n" \ 214" .align 4\n" \ 215#x ":\n" \ 216" l32i a8, %0, 0\n" \ 217" l32i a8, a8, %1\n" \ 218" jx a8\n" \ 219 : : "r"(jt), "i" (FO(x)) : "a8"); 220#elif defined(__XTENSA_WINDOWED_ABI__) 221#if XCHAL_HAVE_BE 222# define SFT "8" 223#else 224# define SFT "12" 225#endif 226#define EXPORT_FUNC(f, a, x, ...) \ 227 asm volatile ( \ 228" .extern jt\n" \ 229" .globl " #x "\n" \ 230" .align 4\n" \ 231#x ":\n" \ 232" entry sp, 16\n" \ 233" l32i a8, %0, 0\n" \ 234" l32i a8, a8, %1\n" \ 235" l32i a9, a8, 0\n" \ 236" extui a9, a9, " SFT ", 12\n" \ 237" subx8 a9, a9, sp\n" \ 238" movi a10, 16\n" \ 239" sub a9, a10, a9\n" \ 240" movsp sp, a9\n" \ 241" addi a8, a8, 3\n" \ 242" jx a8\n" \ 243 : : "r"(jt), "i" (FO(x)) : "a8", "a9", "a10"); 244#else 245#error Unsupported Xtensa ABI 246#endif 247#else 248/*" addi $sp, $sp, -24\n" \ 249" br $r16\n" \*/ 250 251#error stubs definition missing for this architecture 252#endif 253 254/* This function is necessary to prevent the compiler from 255 * generating prologue/epilogue, preparing stack frame etc. 256 * The stub functions are special, they do not use the stack 257 * frame passed to them, but pass it intact to the actual 258 * implementation. On the other hand, asm() statements with 259 * arguments can be used only inside the functions (gcc limitation) 260 */ 261#if GCC_VERSION < 30400 262static 263#endif /* GCC_VERSION */ 264void __attribute__((unused)) dummy(void) 265{ 266#include <_exports.h> 267} 268 269#include <asm/sections.h> 270 271void app_startup(char * const *argv) 272{ 273 char *cp = __bss_start; 274 275 /* Zero out BSS */ 276 while (cp < _end) 277 *cp++ = 0; 278 279#if defined(CONFIG_X86) 280 /* x86 does not have a dedicated register for passing global_data */ 281 global_data = (gd_t *)argv[-1]; 282 jt = global_data->jt; 283#endif 284} 285 286#undef EXPORT_FUNC 287