/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_RUNTIME_CONST_H
#define _ASM_RUNTIME_CONST_H

#ifdef MODULE
  #error "Cannot use runtime-const infrastructure from modules"
#endif

#include <asm/cacheflush.h>

/* Sigh. You can still run arm64 in BE mode */
#include <asm/byteorder.h>

#define runtime_const_ptr(sym) ({                               \
        typeof(sym) __ret;                                      \
        asm_inline("1:\t"                                       \
                "movz %0, #0xcdef\n\t"                          \
                "movk %0, #0x89ab, lsl #16\n\t"                 \
                "movk %0, #0x4567, lsl #32\n\t"                 \
                "movk %0, #0x0123, lsl #48\n\t"                 \
                ".pushsection runtime_ptr_" #sym ",\"a\"\n\t"   \
                ".long 1b - .\n\t"                              \
                ".popsection"                                   \
                :"=r" (__ret));                                 \
        __ret; })

#define runtime_const_shift_right_32(val, sym) ({               \
        unsigned long __ret;                                    \
        asm_inline("1:\t"                                       \
                "lsr %w0,%w1,#12\n\t"                           \
                ".pushsection runtime_shift_" #sym ",\"a\"\n\t" \
                ".long 1b - .\n\t"                              \
                ".popsection"                                   \
                :"=r" (__ret)                                   \
                :"r" (0u+(val)));                               \
        __ret; })

#define runtime_const_init(type, sym) do {              \
        extern s32 __start_runtime_##type##_##sym[];    \
        extern s32 __stop_runtime_##type##_##sym[];     \
        runtime_const_fixup(__runtime_fixup_##type,     \
                (unsigned long)(sym),                   \
                __start_runtime_##type##_##sym,         \
                __stop_runtime_##type##_##sym);         \
} while (0)

/* 16-bit immediate for wide move (movz and movk) in bits 5..20 */
static inline void __runtime_fixup_16(__le32 *p, unsigned int val)
{
        u32 insn = le32_to_cpu(*p);
        insn &= 0xffe0001f;
        insn |= (val & 0xffff) << 5;
        *p = cpu_to_le32(insn);
}

static inline void __runtime_fixup_caches(void *where, unsigned int insns)
{
        unsigned long va = (unsigned long)where;
        caches_clean_inval_pou(va, va + 4*insns);
}

static inline void __runtime_fixup_ptr(void *where, unsigned long val)
{
        __le32 *p = lm_alias(where);
        __runtime_fixup_16(p, val);
        __runtime_fixup_16(p+1, val >> 16);
        __runtime_fixup_16(p+2, val >> 32);
        __runtime_fixup_16(p+3, val >> 48);
        __runtime_fixup_caches(where, 4);
}

/* Immediate value is 6 bits starting at bit #16 */
static inline void __runtime_fixup_shift(void *where, unsigned long val)
{
        __le32 *p = lm_alias(where);
        u32 insn = le32_to_cpu(*p);
        insn &= 0xffc0ffff;
        insn |= (val & 63) << 16;
        *p = cpu_to_le32(insn);
        __runtime_fixup_caches(where, 1);
}

static inline void runtime_const_fixup(void (*fn)(void *, unsigned long),
        unsigned long val, s32 *start, s32 *end)
{
        while (start < end) {
                fn(*start + (void *)start, val);
                start++;
        }
}

#endif