1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_RUNTIME_CONST_H 3 #define _ASM_RUNTIME_CONST_H 4 5 #ifdef __ASSEMBLY__ 6 7 .macro RUNTIME_CONST_PTR sym reg 8 movq $0x0123456789abcdef, %\reg 9 1: 10 .pushsection runtime_ptr_\sym, "a" 11 .long 1b - 8 - . 12 .popsection 13 .endm 14 15 #else /* __ASSEMBLY__ */ 16 17 #define runtime_const_ptr(sym) ({ \ 18 typeof(sym) __ret; \ 19 asm_inline("mov %1,%0\n1:\n" \ 20 ".pushsection runtime_ptr_" #sym ",\"a\"\n\t" \ 21 ".long 1b - %c2 - .\n" \ 22 ".popsection" \ 23 :"=r" (__ret) \ 24 :"i" ((unsigned long)0x0123456789abcdefull), \ 25 "i" (sizeof(long))); \ 26 __ret; }) 27 28 // The 'typeof' will create at _least_ a 32-bit type, but 29 // will happily also take a bigger type and the 'shrl' will 30 // clear the upper bits 31 #define runtime_const_shift_right_32(val, sym) ({ \ 32 typeof(0u+(val)) __ret = (val); \ 33 asm_inline("shrl $12,%k0\n1:\n" \ 34 ".pushsection runtime_shift_" #sym ",\"a\"\n\t" \ 35 ".long 1b - 1 - .\n" \ 36 ".popsection" \ 37 :"+r" (__ret)); \ 38 __ret; }) 39 40 #define runtime_const_init(type, sym) do { \ 41 extern s32 __start_runtime_##type##_##sym[]; \ 42 extern s32 __stop_runtime_##type##_##sym[]; \ 43 runtime_const_fixup(__runtime_fixup_##type, \ 44 (unsigned long)(sym), \ 45 __start_runtime_##type##_##sym, \ 46 __stop_runtime_##type##_##sym); \ 47 } while (0) 48 49 /* 50 * The text patching is trivial - you can only do this at init time, 51 * when the text section hasn't been marked RO, and before the text 52 * has ever been executed. 53 */ 54 static inline void __runtime_fixup_ptr(void *where, unsigned long val) 55 { 56 *(unsigned long *)where = val; 57 } 58 59 static inline void __runtime_fixup_shift(void *where, unsigned long val) 60 { 61 *(unsigned char *)where = val; 62 } 63 64 static inline void runtime_const_fixup(void (*fn)(void *, unsigned long), 65 unsigned long val, s32 *start, s32 *end) 66 { 67 while (start < end) { 68 fn(*start + (void *)start, val); 69 start++; 70 } 71 } 72 73 #endif /* __ASSEMBLY__ */ 74 #endif 75