diff options
| -rw-r--r-- | arch/s390/include/asm/alternative.h | 9 | ||||
| -rw-r--r-- | arch/s390/include/asm/machine.h | 76 | ||||
| -rw-r--r-- | arch/s390/kernel/alternative.c | 7 |
3 files changed, 90 insertions, 2 deletions
diff --git a/arch/s390/include/asm/alternative.h b/arch/s390/include/asm/alternative.h index 73e781b56bfe..67abef07ac93 100644 --- a/arch/s390/include/asm/alternative.h +++ b/arch/s390/include/asm/alternative.h @@ -32,8 +32,9 @@ #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_TYPE_FEATURE 1 +#define ALT_TYPE_SPEC 2 +#define ALT_TYPE_LOWCORE 3 #define ALT_DATA_SHIFT 0 #define ALT_TYPE_SHIFT 20 @@ -43,6 +44,10 @@ ALT_TYPE_FACILITY << ALT_TYPE_SHIFT | \ (facility) << ALT_DATA_SHIFT) +#define ALT_FEATURE(feature) (ALT_CTX_EARLY << ALT_CTX_SHIFT | \ + ALT_TYPE_FEATURE << ALT_TYPE_SHIFT | \ + (feature) << ALT_DATA_SHIFT) + #define ALT_SPEC(facility) (ALT_CTX_LATE << ALT_CTX_SHIFT | \ ALT_TYPE_SPEC << ALT_TYPE_SHIFT | \ (facility) << ALT_DATA_SHIFT) diff --git a/arch/s390/include/asm/machine.h b/arch/s390/include/asm/machine.h new file mode 100644 index 000000000000..bbe6c24bfc88 --- /dev/null +++ b/arch/s390/include/asm/machine.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright IBM Corp. 2024 + */ + +#ifndef __ASM_S390_MACHINE_H +#define __ASM_S390_MACHINE_H + +#ifndef __ASSEMBLY__ + +#include <linux/bitops.h> +#include <asm/alternative.h> + +extern unsigned long machine_features[1]; + +#define MAX_MFEATURE_BIT (sizeof(machine_features) * BITS_PER_BYTE) + +static inline void __set_machine_feature(unsigned int nr, unsigned long *mfeatures) +{ + if (nr >= MAX_MFEATURE_BIT) + return; + __set_bit(nr, mfeatures); +} + +static inline void set_machine_feature(unsigned int nr) +{ + __set_machine_feature(nr, machine_features); +} + +static inline void __clear_machine_feature(unsigned int nr, unsigned long *mfeatures) +{ + if (nr >= MAX_MFEATURE_BIT) + return; + __clear_bit(nr, mfeatures); +} + +static inline void clear_machine_feature(unsigned int nr) +{ + __clear_machine_feature(nr, machine_features); +} + +static bool __test_machine_feature(unsigned int nr, unsigned long *mfeatures) +{ + if (nr >= MAX_MFEATURE_BIT) + return false; + return test_bit(nr, mfeatures); +} + +static bool test_machine_feature(unsigned int nr) +{ + return __test_machine_feature(nr, machine_features); +} + +static __always_inline bool __test_machine_feature_constant(unsigned int nr) +{ + asm goto( + ALTERNATIVE("brcl 15,%l[l_no]", "brcl 0,0", ALT_FEATURE(%[nr])) + : + : [nr] "i" (nr) + : + : l_no); + return true; +l_no: + return false; +} + +#define DEFINE_MACHINE_HAS_FEATURE(name, feature) \ +static __always_inline bool machine_has_##name(void) \ +{ \ + if (!__is_defined(__DECOMPRESSOR) && __builtin_constant_p(feature)) \ + return __test_machine_feature_constant(feature); \ + return test_machine_feature(feature); \ +} + +#endif /* __ASSEMBLY__ */ +#endif /* __ASM_S390_MACHINE_H */ diff --git a/arch/s390/kernel/alternative.c b/arch/s390/kernel/alternative.c index 8d5d0de35de0..d3839fc0543d 100644 --- a/arch/s390/kernel/alternative.c +++ b/arch/s390/kernel/alternative.c @@ -5,6 +5,10 @@ #include <asm/abs_lowcore.h> #include <asm/alternative.h> #include <asm/facility.h> +#include <asm/sections.h> +#include <asm/machine.h> + +unsigned long __bootdata_preserved(machine_features[1]); void __apply_alternatives(struct alt_instr *start, struct alt_instr *end, unsigned int ctx) { @@ -23,6 +27,9 @@ void __apply_alternatives(struct alt_instr *start, struct alt_instr *end, unsign case ALT_TYPE_FACILITY: replace = test_facility(a->data); break; + case ALT_TYPE_FEATURE: + replace = test_machine_feature(a->data); + break; case ALT_TYPE_SPEC: replace = nobp_enabled(); break; |