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 */
44static 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
52static 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
58static 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 */
69static 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
79static 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