diff options
Diffstat (limited to 'arch/s390/include/asm/alternative.h')
| -rw-r--r-- | arch/s390/include/asm/alternative.h | 66 |
1 files changed, 61 insertions, 5 deletions
diff --git a/arch/s390/include/asm/alternative.h b/arch/s390/include/asm/alternative.h index 16de33750d6c..5b931070be16 100644 --- a/arch/s390/include/asm/alternative.h +++ b/arch/s390/include/asm/alternative.h @@ -2,6 +2,44 @@ #ifndef _ASM_S390_ALTERNATIVE_H #define _ASM_S390_ALTERNATIVE_H +/* + * Each alternative comes with a 32 bit feature field: + * union { + * u32 feature; + * struct { + * u32 ctx : 4; + * u32 type : 8; + * u32 data : 20; + * }; + * } + * + * @ctx is a bitfield, where only one bit must be set. Each bit defines + * in which context an alternative is supposed to be applied to the + * kernel image: + * + * - from the decompressor before the kernel itself is executed + * - from early kernel code from within the kernel + * + * @type is a number which defines the type and with that the type + * specific alternative patching. + * + * @data is additional type specific information which defines if an + * alternative should be applied. + */ + +#define ALT_CTX_LATE 1 +#define ALT_CTX_ALL ALT_CTX_LATE + +#define ALT_TYPE_FACILITY 0 + +#define ALT_DATA_SHIFT 0 +#define ALT_TYPE_SHIFT 20 +#define ALT_CTX_SHIFT 28 + +#define ALT_FACILITY(facility) (ALT_CTX_LATE << ALT_CTX_SHIFT | \ + ALT_TYPE_FACILITY << ALT_TYPE_SHIFT | \ + (facility) << ALT_DATA_SHIFT) + #ifndef __ASSEMBLY__ #include <linux/types.h> @@ -11,12 +49,30 @@ struct alt_instr { s32 instr_offset; /* original instruction */ s32 repl_offset; /* offset to replacement instruction */ - u16 feature; /* feature required for replacement */ + union { + u32 feature; /* feature required for replacement */ + struct { + u32 ctx : 4; /* context */ + u32 type : 8; /* type of alternative */ + u32 data : 20; /* patching information */ + }; + }; u8 instrlen; /* length of original instruction */ } __packed; -void apply_alternative_instructions(void); -void apply_alternatives(struct alt_instr *start, struct alt_instr *end); +extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; + +void __apply_alternatives(struct alt_instr *start, struct alt_instr *end, unsigned int ctx); + +static inline void apply_alternative_instructions(void) +{ + __apply_alternatives(__alt_instructions, __alt_instructions_end, ALT_CTX_LATE); +} + +static inline void apply_alternatives(struct alt_instr *start, struct alt_instr *end) +{ + __apply_alternatives(start, end, ALT_CTX_ALL); +} /* * +---------------------------------+ @@ -51,7 +107,7 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); #define ALTINSTR_ENTRY(feature, num) \ "\t.long 661b - .\n" /* old instruction */ \ "\t.long " b_altinstr(num)"b - .\n" /* alt instruction */ \ - "\t.word " __stringify(feature) "\n" /* feature */ \ + "\t.long " __stringify(feature) "\n" /* feature */ \ "\t.byte " oldinstr_len "\n" /* instruction len */ \ "\t.org . - (" oldinstr_len ") & 1\n" \ "\t.org . - (" oldinstr_len ") + (" altinstr_len(num) ")\n" \ @@ -127,7 +183,7 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); .macro alt_entry orig_start, orig_end, alt_start, alt_end, feature .long \orig_start - . .long \alt_start - . - .word \feature + .long \feature .byte \orig_end - \orig_start .org . - ( \orig_end - \orig_start ) & 1 .org . - ( \orig_end - \orig_start ) + ( \alt_end - \alt_start ) |