diff options
Diffstat (limited to 'arch/s390/include/asm/alternative.h')
| -rw-r--r-- | arch/s390/include/asm/alternative.h | 154 |
1 files changed, 137 insertions, 17 deletions
diff --git a/arch/s390/include/asm/alternative.h b/arch/s390/include/asm/alternative.h index dd93b92c3ab6..de980c938a3e 100644 --- a/arch/s390/include/asm/alternative.h +++ b/arch/s390/include/asm/alternative.h @@ -2,6 +2,58 @@ #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_EARLY 1 +#define ALT_CTX_LATE 2 +#define ALT_CTX_ALL (ALT_CTX_EARLY | ALT_CTX_LATE) + +#define ALT_TYPE_FACILITY 0 +#define ALT_TYPE_SPEC 1 +#define ALT_TYPE_LOWCORE 2 + +#define ALT_DATA_SHIFT 0 +#define ALT_TYPE_SHIFT 20 +#define ALT_CTX_SHIFT 28 + +#define ALT_FACILITY_EARLY(facility) (ALT_CTX_EARLY << ALT_CTX_SHIFT | \ + ALT_TYPE_FACILITY << ALT_TYPE_SHIFT | \ + (facility) << ALT_DATA_SHIFT) + +#define ALT_FACILITY(facility) (ALT_CTX_LATE << ALT_CTX_SHIFT | \ + ALT_TYPE_FACILITY << ALT_TYPE_SHIFT | \ + (facility) << ALT_DATA_SHIFT) + +#define ALT_SPEC(facility) (ALT_CTX_LATE << ALT_CTX_SHIFT | \ + ALT_TYPE_SPEC << ALT_TYPE_SHIFT | \ + (facility) << ALT_DATA_SHIFT) + +#define ALT_LOWCORE (ALT_CTX_EARLY << ALT_CTX_SHIFT | \ + ALT_TYPE_LOWCORE << ALT_TYPE_SHIFT) + #ifndef __ASSEMBLY__ #include <linux/types.h> @@ -11,12 +63,30 @@ struct alt_instr { s32 instr_offset; /* original instruction */ s32 repl_offset; /* offset to replacement instruction */ - u16 facility; /* facility bit set 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); +} /* * +---------------------------------+ @@ -48,10 +118,10 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); #define OLDINSTR(oldinstr) \ "661:\n\t" oldinstr "\n662:\n" -#define ALTINSTR_ENTRY(facility, num) \ +#define ALTINSTR_ENTRY(feature, num) \ "\t.long 661b - .\n" /* old instruction */ \ "\t.long " b_altinstr(num)"b - .\n" /* alt instruction */ \ - "\t.word " __stringify(facility) "\n" /* facility bit */ \ + "\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" \ @@ -61,24 +131,24 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); b_altinstr(num)":\n\t" altinstr "\n" e_altinstr(num) ":\n" /* alternative assembly primitive: */ -#define ALTERNATIVE(oldinstr, altinstr, facility) \ +#define ALTERNATIVE(oldinstr, altinstr, feature) \ ".pushsection .altinstr_replacement, \"ax\"\n" \ ALTINSTR_REPLACEMENT(altinstr, 1) \ ".popsection\n" \ OLDINSTR(oldinstr) \ ".pushsection .altinstructions,\"a\"\n" \ - ALTINSTR_ENTRY(facility, 1) \ + ALTINSTR_ENTRY(feature, 1) \ ".popsection\n" -#define ALTERNATIVE_2(oldinstr, altinstr1, facility1, altinstr2, facility2)\ +#define ALTERNATIVE_2(oldinstr, altinstr1, feature1, altinstr2, feature2)\ ".pushsection .altinstr_replacement, \"ax\"\n" \ ALTINSTR_REPLACEMENT(altinstr1, 1) \ ALTINSTR_REPLACEMENT(altinstr2, 2) \ ".popsection\n" \ OLDINSTR(oldinstr) \ ".pushsection .altinstructions,\"a\"\n" \ - ALTINSTR_ENTRY(facility1, 1) \ - ALTINSTR_ENTRY(facility2, 2) \ + ALTINSTR_ENTRY(feature1, 1) \ + ALTINSTR_ENTRY(feature2, 2) \ ".popsection\n" /* @@ -93,12 +163,12 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); * For non barrier like inlines please define new variants * without volatile and memory clobber. */ -#define alternative(oldinstr, altinstr, facility) \ - asm_inline volatile(ALTERNATIVE(oldinstr, altinstr, facility) : : : "memory") +#define alternative(oldinstr, altinstr, feature) \ + asm_inline volatile(ALTERNATIVE(oldinstr, altinstr, feature) : : : "memory") -#define alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2) \ - asm_inline volatile(ALTERNATIVE_2(oldinstr, altinstr1, facility1, \ - altinstr2, facility2) ::: "memory") +#define alternative_2(oldinstr, altinstr1, feature1, altinstr2, feature2) \ + asm_inline volatile(ALTERNATIVE_2(oldinstr, altinstr1, feature1, \ + altinstr2, feature2) ::: "memory") /* Alternative inline assembly with input. */ #define alternative_input(oldinstr, newinstr, feature, input...) \ @@ -106,8 +176,8 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); : : input) /* Like alternative_input, but with a single output argument */ -#define alternative_io(oldinstr, altinstr, facility, output, input...) \ - asm_inline volatile(ALTERNATIVE(oldinstr, altinstr, facility) \ +#define alternative_io(oldinstr, altinstr, feature, output, input...) \ + asm_inline volatile(ALTERNATIVE(oldinstr, altinstr, feature) \ : output : input) /* Use this macro if more than one output parameter is needed. */ @@ -116,6 +186,56 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); /* Use this macro if clobbers are needed without inputs. */ #define ASM_NO_INPUT_CLOBBER(clobber...) : clobber +#else /* __ASSEMBLY__ */ + +/* + * Issue one struct alt_instr descriptor entry (need to put it into + * the section .altinstructions, see below). This entry contains + * enough information for the alternatives patching code to patch an + * instruction. See apply_alternatives(). + */ +.macro alt_entry orig_start, orig_end, alt_start, alt_end, feature + .long \orig_start - . + .long \alt_start - . + .long \feature + .byte \orig_end - \orig_start + .org . - ( \orig_end - \orig_start ) & 1 + .org . - ( \orig_end - \orig_start ) + ( \alt_end - \alt_start ) + .org . - ( \alt_end - \alt_start ) + ( \orig_end - \orig_start ) +.endm + +/* + * Define an alternative between two instructions. If @feature is + * present, early code in apply_alternatives() replaces @oldinstr with + * @newinstr. + */ +.macro ALTERNATIVE oldinstr, newinstr, feature + .pushsection .altinstr_replacement,"ax" +770: \newinstr +771: .popsection +772: \oldinstr +773: .pushsection .altinstructions,"a" + alt_entry 772b, 773b, 770b, 771b, \feature + .popsection +.endm + +/* + * Define an alternative between two instructions. If @feature is + * present, early code in apply_alternatives() replaces @oldinstr with + * @newinstr. + */ +.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2 + .pushsection .altinstr_replacement,"ax" +770: \newinstr1 +771: \newinstr2 +772: .popsection +773: \oldinstr +774: .pushsection .altinstructions,"a" + alt_entry 773b, 774b, 770b, 771b,\feature1 + alt_entry 773b, 774b, 771b, 772b,\feature2 + .popsection +.endm + #endif /* __ASSEMBLY__ */ #endif /* _ASM_S390_ALTERNATIVE_H */ |