LXR linux/arch/parisc/include/asm/alternative.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __ASM_PARISC_ALTERNATIVE_H
   3#define __ASM_PARISC_ALTERNATIVE_H
   4
   5#define ALT_COND_ALWAYS         0x80    /* always replace instruction */
   6#define ALT_COND_NO_SMP         0x01    /* when running UP instead of SMP */
   7#define ALT_COND_NO_DCACHE      0x02    /* if system has no d-cache  */
   8#define ALT_COND_NO_ICACHE      0x04    /* if system has no i-cache  */
   9#define ALT_COND_NO_SPLIT_TLB   0x08    /* if split_tlb == 0  */
  10#define ALT_COND_NO_IOC_FDC     0x10    /* if I/O cache does not need flushes */
  11#define ALT_COND_RUN_ON_QEMU    0x20    /* if running on QEMU */
  12
  13#define INSN_PxTLB      0x02            /* modify pdtlb, pitlb */
  14#define INSN_NOP        0x08000240      /* nop */
  15
  16#ifndef __ASSEMBLY__
  17
  18#include <linux/init.h>
  19#include <linux/types.h>
  20#include <linux/stddef.h>
  21#include <linux/stringify.h>
  22
  23struct alt_instr {
  24        s32 orig_offset;        /* offset to original instructions */
  25        s32 len;                /* end of original instructions */
  26        u32 cond;               /* see ALT_COND_XXX */
  27        u32 replacement;        /* replacement instruction or code */
  28};
  29
  30void set_kernel_text_rw(int enable_read_write);
  31void apply_alternatives_all(void);
  32void apply_alternatives(struct alt_instr *start, struct alt_instr *end,
  33        const char *module_name);
  34
  35/* Alternative SMP implementation. */
  36#define ALTERNATIVE(cond, replacement)          "!0:"   \
  37        ".section .altinstructions, \"aw\"      !"      \
  38        ".word (0b-4-.), 1, " __stringify(cond) ","     \
  39                __stringify(replacement) "      !"      \
  40        ".previous"
  41
  42#else
  43
  44/* to replace one single instructions by a new instruction */
  45#define ALTERNATIVE(from, to, cond, replacement)\
  46        .section .altinstructions, "aw" !       \
  47        .word (from - .), (to - from)/4 !       \
  48        .word cond, replacement         !       \
  49        .previous
  50
  51/* to replace multiple instructions by new code */
  52#define ALTERNATIVE_CODE(from, num_instructions, cond, new_instr_ptr)\
  53        .section .altinstructions, "aw" !       \
  54        .word (from - .), -num_instructions !   \
  55        .word cond, (new_instr_ptr - .) !       \
  56        .previous
  57
  58#endif  /*  __ASSEMBLY__  */
  59
  60#endif /* __ASM_PARISC_ALTERNATIVE_H */
  61