arch/arm64/include/asm/runtime-const.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_RUNTIME_CONST_H
   3 #define _ASM_RUNTIME_CONST_H
   4
   5 #include <asm/cacheflush.h>
   6
   7 /* Sigh. You can still run arm64 in BE mode */
   8 #include <asm/byteorder.h>
   9
  10 #define runtime_const_ptr(sym) ({                               \
  11         typeof(sym) __ret;                                      \
  12         asm_inline("1:\t"                                       \
  13                 "movz %0, #0xcdef\n\t"                          \
  14                 "movk %0, #0x89ab, lsl #16\n\t"                 \
  15                 "movk %0, #0x4567, lsl #32\n\t"                 \
  16                 "movk %0, #0x0123, lsl #48\n\t"                 \
  17                 ".pushsection runtime_ptr_" #sym ",\"a\"\n\t"   \
  18                 ".long 1b - .\n\t"                              \
  19                 ".popsection"                                   \
  20                 :"=r" (__ret));                                 \
  21         __ret; })
  22
  23 #define runtime_const_shift_right_32(val, sym) ({               \
  24         unsigned long __ret;                                    \
  25         asm_inline("1:\t"                                       \
  26                 "lsr %w0,%w1,#12\n\t"                           \
  27                 ".pushsection runtime_shift_" #sym ",\"a\"\n\t" \
  28                 ".long 1b - .\n\t"                              \
  29                 ".popsection"                                   \
  30                 :"=r" (__ret)                                   \
  31                 :"r" (0u+(val)));                               \
  32         __ret; })
  33
  34 #define runtime_const_init(type, sym) do {              \
  35         extern s32 __start_runtime_##type##_##sym[];    \
  36         extern s32 __stop_runtime_##type##_##sym[];     \
  37         runtime_const_fixup(__runtime_fixup_##type,     \
  38                 (unsigned long)(sym),                   \
  39                 __start_runtime_##type##_##sym,         \
  40                 __stop_runtime_##type##_##sym);         \
  41 } while (0)
  42
  43 /* 16-bit immediate for wide move (movz and movk) in bits 5..20 */
  44 static inline void __runtime_fixup_16(__le32 *p, unsigned int val)
  45 {
  46         u32 insn = le32_to_cpu(*p);
  47         insn &= 0xffe0001f;
  48         insn |= (val & 0xffff) << 5;
  49         *p = cpu_to_le32(insn);
  50 }
  51
  52 static inline void __runtime_fixup_caches(void *where, unsigned int insns)
  53 {
  54         unsigned long va = (unsigned long)where;
  55         caches_clean_inval_pou(va, va + 4*insns);
  56 }
  57
  58 static inline void __runtime_fixup_ptr(void *where, unsigned long val)
  59 {
  60         __le32 *p = lm_alias(where);
  61         __runtime_fixup_16(p, val);
  62         __runtime_fixup_16(p+1, val >> 16);
  63         __runtime_fixup_16(p+2, val >> 32);
  64         __runtime_fixup_16(p+3, val >> 48);
  65         __runtime_fixup_caches(where, 4);
  66 }
  67
  68 /* Immediate value is 6 bits starting at bit #16 */
  69 static inline void __runtime_fixup_shift(void *where, unsigned long val)
  70 {
  71         __le32 *p = lm_alias(where);
  72         u32 insn = le32_to_cpu(*p);
  73         insn &= 0xffc0ffff;
  74         insn |= (val & 63) << 16;
  75         *p = cpu_to_le32(insn);
  76         __runtime_fixup_caches(where, 1);
  77 }
  78
  79 static inline void runtime_const_fixup(void (*fn)(void *, unsigned long),
  80         unsigned long val, s32 *start, s32 *end)
  81 {
  82         while (start < end) {
  83                 fn(*start + (void *)start, val);
  84                 start++;
  85         }
  86 }
  87
  88 #endif