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

#define ALT_COND_ALWAYS         0x80    /* always replace instruction */
#define ALT_COND_NO_SMP         0x01    /* when running UP instead of SMP */
#define ALT_COND_NO_DCACHE      0x02    /* if system has no d-cache  */
#define ALT_COND_NO_ICACHE      0x04    /* if system has no i-cache  */
#define ALT_COND_NO_SPLIT_TLB   0x08    /* if split_tlb == 0  */
#define ALT_COND_NO_IOC_FDC     0x10    /* if I/O cache does not need flushes */
#define ALT_COND_RUN_ON_QEMU    0x20    /* if running on QEMU */

#define INSN_PxTLB      0x02            /* modify pdtlb, pitlb */
#define INSN_NOP        0x08000240      /* nop */

#ifndef __ASSEMBLER__

#include <linux/init.h>
#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/stringify.h>

struct alt_instr {
        s32 orig_offset;        /* offset to original instructions */
        s16 len;                /* end of original instructions */
        u16 cond;               /* see ALT_COND_XXX */
        u32 replacement;        /* replacement instruction or code */
} __packed;

void set_kernel_text_rw(int enable_read_write);
void apply_alternatives_all(void);
void apply_alternatives(struct alt_instr *start, struct alt_instr *end,
        const char *module_name);

/* Alternative SMP implementation. */
#define ALTERNATIVE(cond, replacement)          "!0:"   \
        ".section .altinstructions, \"a\"       !"      \
        ".align 4                               !"      \
        ".word (0b-4-.)                         !"      \
        ".hword 1, " __stringify(cond) "        !"      \
        ".word " __stringify(replacement) "     !"      \
        ".previous"

#else

/* to replace one single instructions by a new instruction */
#define ALTERNATIVE(from, to, cond, replacement)\
        .section .altinstructions, "a"  !       \
        .align 4                        !       \
        .word (from - .)                !       \
        .hword (to - from)/4, cond      !       \
        .word replacement               !       \
        .previous

/* to replace multiple instructions by new code */
#define ALTERNATIVE_CODE(from, num_instructions, cond, new_instr_ptr)\
        .section .altinstructions, "a"  !       \
        .align 4                        !       \
        .word (from - .)                !       \
        .hword -num_instructions, cond  !       \
        .word (new_instr_ptr - .)       !       \
        .previous

#endif  /*  __ASSEMBLER__  */

#endif /* __ASM_PARISC_ALTERNATIVE_H */