| #include <common.h> |
| #include <exports.h> |
| #include <linux/compiler.h> |
| |
| #define FO(x) offsetof(struct jt_funcs, x) |
| |
| #if defined(CONFIG_X86) |
| /* |
| * x86 does not have a dedicated register to store the pointer to |
| * the global_data. Thus the jump table address is stored in a |
| * global variable, but such approach does not allow for execution |
| * from flash memory. The global_data address is passed as argv[-1] |
| * to the application program. |
| */ |
| static struct jt_funcs *jt; |
| gd_t *global_data; |
| |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " movl %0, %%eax\n" \ |
| " movl jt, %%ecx\n" \ |
| " jmp *(%%ecx, %%eax)\n" \ |
| : : "i"(FO(x)) : "eax", "ecx"); |
| #elif defined(CONFIG_PPC) |
| /* |
| * r2 holds the pointer to the global_data, r11 is a call-clobbered |
| * register |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " lwz %%r11, %0(%%r2)\n" \ |
| " lwz %%r11, %1(%%r11)\n" \ |
| " mtctr %%r11\n" \ |
| " bctr\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r11"); |
| #elif defined(CONFIG_ARM) |
| #ifdef CONFIG_ARM64 |
| /* |
| * x18 holds the pointer to the global_data, x9 is a call-clobbered |
| * register |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " ldr x9, [x18, %0]\n" \ |
| " ldr x9, [x9, %1]\n" \ |
| " br x9\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "x9"); |
| #else |
| /* |
| * r9 holds the pointer to the global_data, ip is a call-clobbered |
| * register |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " ldr ip, [r9, %0]\n" \ |
| " ldr pc, [ip, %1]\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "ip"); |
| #endif |
| #elif defined(CONFIG_MIPS) |
| #ifdef CONFIG_CPU_MIPS64 |
| /* |
| * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- |
| * clobbered register that is also used to set gp ($26). Note that the |
| * jr instruction also executes the instruction immediately following |
| * it; however, GCC/mips generates an additional `nop' after each asm |
| * statement |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " ld $25, %0($26)\n" \ |
| " ld $25, %1($25)\n" \ |
| " jr $25\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9"); |
| #else |
| /* |
| * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- |
| * clobbered register that is also used to set gp ($26). Note that the |
| * jr instruction also executes the instruction immediately following |
| * it; however, GCC/mips generates an additional `nop' after each asm |
| * statement |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " lw $25, %0($26)\n" \ |
| " lw $25, %1($25)\n" \ |
| " jr $25\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9"); |
| #endif |
| #elif defined(CONFIG_NIOS2) |
| /* |
| * gp holds the pointer to the global_data, r8 is call-clobbered |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " movhi r8, %%hi(%0)\n" \ |
| " ori r8, r0, %%lo(%0)\n" \ |
| " add r8, r8, gp\n" \ |
| " ldw r8, 0(r8)\n" \ |
| " ldw r8, %1(r8)\n" \ |
| " jmp r8\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "gp"); |
| #elif defined(CONFIG_M68K) |
| /* |
| * d7 holds the pointer to the global_data, a0 is a call-clobbered |
| * register |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " move.l %%d7, %%a0\n" \ |
| " adda.l %0, %%a0\n" \ |
| " move.l (%%a0), %%a0\n" \ |
| " adda.l %1, %%a0\n" \ |
| " move.l (%%a0), %%a0\n" \ |
| " jmp (%%a0)\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "a0"); |
| #elif defined(CONFIG_MICROBLAZE) |
| /* |
| * r31 holds the pointer to the global_data. r5 is a call-clobbered. |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " lwi r5, r31, %0\n" \ |
| " lwi r5, r5, %1\n" \ |
| " bra r5\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r5"); |
| #elif defined(CONFIG_SH) |
| /* |
| * r13 holds the pointer to the global_data. r1 is a call clobbered. |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .align 2\n" \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " mov r13, r1\n" \ |
| " add %0, r1\n" \ |
| " mov.l @r1, r2\n" \ |
| " add %1, r2\n" \ |
| " mov.l @r2, r1\n" \ |
| " jmp @r1\n" \ |
| " nop\n" \ |
| " nop\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r1", "r2"); |
| #elif defined(CONFIG_NDS32) |
| /* |
| * r16 holds the pointer to the global_data. gp is call clobbered. |
| * not support reduced register (16 GPR). |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " lwi $r16, [$gp + (%0)]\n" \ |
| " lwi $r16, [$r16 + (%1)]\n" \ |
| " jr $r16\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "$r16"); |
| #elif defined(CONFIG_RISCV) |
| /* |
| * t7 holds the pointer to the global_data. gp is call clobbered. |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " lw x19, %0(gp)\n" \ |
| " lw x19, %1(x19)\n" \ |
| " jr x19\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "x19"); |
| #elif defined(CONFIG_ARC) |
| /* |
| * r25 holds the pointer to the global_data. r10 is call clobbered. |
| */ |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile( \ |
| " .align 4\n" \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " ld r10, [r25, %0]\n" \ |
| " ld r10, [r10, %1]\n" \ |
| " j [r10]\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r10"); |
| #elif defined(CONFIG_XTENSA) |
| /* |
| * Global data ptr is in global_data, jump table ptr is in jt. |
| * Windowed ABI: Jump just past 'entry' in target and adjust stack frame |
| * (extract stack frame size from target 'entry' instruction). |
| */ |
| |
| static void **jt; |
| |
| #if defined(__XTENSA_CALL0_ABI__) |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .extern jt\n" \ |
| " .globl " #x "\n" \ |
| " .align 4\n" \ |
| #x ":\n" \ |
| " l32i a8, %0, 0\n" \ |
| " l32i a8, a8, %1\n" \ |
| " jx a8\n" \ |
| : : "r"(jt), "i" (FO(x)) : "a8"); |
| #elif defined(__XTENSA_WINDOWED_ABI__) |
| #if XCHAL_HAVE_BE |
| # define SFT "8" |
| #else |
| # define SFT "12" |
| #endif |
| #define EXPORT_FUNC(f, a, x, ...) \ |
| asm volatile ( \ |
| " .extern jt\n" \ |
| " .globl " #x "\n" \ |
| " .align 4\n" \ |
| #x ":\n" \ |
| " entry sp, 16\n" \ |
| " l32i a8, %0, 0\n" \ |
| " l32i a8, a8, %1\n" \ |
| " l32i a9, a8, 0\n" \ |
| " extui a9, a9, " SFT ", 12\n" \ |
| " subx8 a9, a9, sp\n" \ |
| " movi a10, 16\n" \ |
| " sub a9, a10, a9\n" \ |
| " movsp sp, a9\n" \ |
| " addi a8, a8, 3\n" \ |
| " jx a8\n" \ |
| : : "r"(jt), "i" (FO(x)) : "a8", "a9", "a10"); |
| #else |
| #error Unsupported Xtensa ABI |
| #endif |
| #else |
| /*" addi $sp, $sp, -24\n" \ |
| " br $r16\n" \*/ |
| |
| #error stubs definition missing for this architecture |
| #endif |
| |
| /* This function is necessary to prevent the compiler from |
| * generating prologue/epilogue, preparing stack frame etc. |
| * The stub functions are special, they do not use the stack |
| * frame passed to them, but pass it intact to the actual |
| * implementation. On the other hand, asm() statements with |
| * arguments can be used only inside the functions (gcc limitation) |
| */ |
| #if GCC_VERSION < 30400 |
| static |
| #endif /* GCC_VERSION */ |
| void __attribute__((unused)) dummy(void) |
| { |
| #include <_exports.h> |
| } |
| |
| #include <asm/sections.h> |
| |
| void app_startup(char * const *argv) |
| { |
| char *cp = __bss_start; |
| |
| /* Zero out BSS */ |
| while (cp < _end) |
| *cp++ = 0; |
| |
| #if defined(CONFIG_X86) |
| /* x86 does not have a dedicated register for passing global_data */ |
| global_data = (gd_t *)argv[-1]; |
| jt = global_data->jt; |
| #endif |
| } |
| |
| #undef EXPORT_FUNC |
