arch/riscv/include/asm/alternative.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2021 Sifive.
   4  */
   5
   6 #ifndef __ASM_ALTERNATIVE_H
   7 #define __ASM_ALTERNATIVE_H
   8
   9 #include <asm/alternative-macros.h>
  10
  11 #ifndef __ASSEMBLY__
  12
  13 #ifdef CONFIG_RISCV_ALTERNATIVE
  14
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/types.h>
  18 #include <linux/stddef.h>
  19 #include <asm/hwcap.h>
  20
  21 #define PATCH_ID_CPUFEATURE_ID(p)               lower_16_bits(p)
  22 #define PATCH_ID_CPUFEATURE_VALUE(p)            upper_16_bits(p)
  23
  24 #define RISCV_ALTERNATIVES_BOOT         0 /* alternatives applied during regular boot */
  25 #define RISCV_ALTERNATIVES_MODULE       1 /* alternatives applied during module-init */
  26 #define RISCV_ALTERNATIVES_EARLY_BOOT   2 /* alternatives applied before mmu start */
  27
  28 /* add the relative offset to the address of the offset to get the absolute address */
  29 #define __ALT_PTR(a, f)                 ((void *)&(a)->f + (a)->f)
  30 #define ALT_OLD_PTR(a)                  __ALT_PTR(a, old_offset)
  31 #define ALT_ALT_PTR(a)                  __ALT_PTR(a, alt_offset)
  32
  33 void __init apply_boot_alternatives(void);
  34 void __init apply_early_boot_alternatives(void);
  35 void apply_module_alternatives(void *start, size_t length);
  36
  37 void riscv_alternative_fix_offsets(void *alt_ptr, unsigned int len,
  38                                    int patch_offset);
  39
  40 struct alt_entry {
  41         s32 old_offset;         /* offset relative to original instruction or data  */
  42         s32 alt_offset;         /* offset relative to replacement instruction or data */
  43         u16 vendor_id;          /* CPU vendor ID */
  44         u16 alt_len;            /* The replacement size */
  45         u32 patch_id;           /* The patch ID (erratum ID or cpufeature ID) */
  46 };
  47
  48 void andes_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
  49                              unsigned long archid, unsigned long impid,
  50                              unsigned int stage);
  51 void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
  52                               unsigned long archid, unsigned long impid,
  53                               unsigned int stage);
  54 void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
  55                              unsigned long archid, unsigned long impid,
  56                              unsigned int stage);
  57
  58 void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end,
  59                                  unsigned int stage);
  60
  61 #else /* CONFIG_RISCV_ALTERNATIVE */
  62
  63 static inline void apply_boot_alternatives(void) { }
  64 static inline void apply_early_boot_alternatives(void) { }
  65 static inline void apply_module_alternatives(void *start, size_t length) { }
  66
  67 #endif /* CONFIG_RISCV_ALTERNATIVE */
  68
  69 #endif
  70 #endif