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
  23 struct 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
  30 void set_kernel_text_rw(int enable_read_write);
  31 void apply_alternatives_all(void);
  32 void 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 */