1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_RUNTIME_CONST_H 3 #define _ASM_RUNTIME_CONST_H 4 5 #ifdef MODULE 6 #error "Cannot use runtime-const infrastructure from modules" 7 #endif 8 9 #ifdef __ASSEMBLER__ 10 11 .macro RUNTIME_CONST_PTR sym reg 12 movq $0x0123456789abcdef, %\reg 13 1: 14 .pushsection runtime_ptr_\sym, "a" 15 .long 1b - 8 - . 16 .popsection 17 .endm 18 19 #else /* __ASSEMBLER__ */ 20 21 #define runtime_const_ptr(sym) ({ \ 22 typeof(sym) __ret; \ 23 asm_inline("mov %1,%0\n1:\n" \ 24 ".pushsection runtime_ptr_" #sym ",\"a\"\n\t" \ 25 ".long 1b - %c2 - .\n" \ 26 ".popsection" \ 27 :"=r" (__ret) \ 28 :"i" ((unsigned long)0x0123456789abcdefull), \ 29 "i" (sizeof(long))); \ 30 __ret; }) 31 32 // The 'typeof' will create at _least_ a 32-bit type, but 33 // will happily also take a bigger type and the 'shrl' will 34 // clear the upper bits 35 #define runtime_const_shift_right_32(val, sym) ({ \ 36 typeof(0u+(val)) __ret = (val); \ 37 asm_inline("shrl $12,%k0\n1:\n" \ 38 ".pushsection runtime_shift_" #sym ",\"a\"\n\t" \ 39 ".long 1b - 1 - .\n" \ 40 ".popsection" \ 41 :"+r" (__ret)); \ 42 __ret; }) 43 44 #define runtime_const_mask_32(val, sym) ({ \ 45 typeof(0u+(val)) __ret = (val); \ 46 asm_inline("and $0x12345678, %k0\n1:\n" \ 47 ".pushsection runtime_mask_" #sym ",\"a\"\n\t"\ 48 ".long 1b - 4 - .\n" \ 49 ".popsection" \ 50 : "+r" (__ret)); \ 51 __ret; }) 52 53 #define runtime_const_init(type, sym) do { \ 54 extern s32 __start_runtime_##type##_##sym[]; \ 55 extern s32 __stop_runtime_##type##_##sym[]; \ 56 runtime_const_fixup(__runtime_fixup_##type, \ 57 (unsigned long)(sym), \ 58 __start_runtime_##type##_##sym, \ 59 __stop_runtime_##type##_##sym); \ 60 } while (0) 61 62 /* 63 * The text patching is trivial - you can only do this at init time, 64 * when the text section hasn't been marked RO, and before the text 65 * has ever been executed. 66 */ 67 static inline void __runtime_fixup_ptr(void *where, unsigned long val) 68 { 69 *(unsigned long *)where = val; 70 } 71 72 static inline void __runtime_fixup_shift(void *where, unsigned long val) 73 { 74 *(unsigned char *)where = val; 75 } 76 77 static inline void __runtime_fixup_mask(void *where, unsigned long val) 78 { 79 *(unsigned int *)where = val; 80 } 81 82 static inline void runtime_const_fixup(void (*fn)(void *, unsigned long), 83 unsigned long val, s32 *start, s32 *end) 84 { 85 while (start < end) { 86 fn(*start + (void *)start, val); 87 start++; 88 } 89 } 90 91 #endif /* __ASSEMBLER__ */ 92 #endif 93