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| author | Hendrik Brueckner <brueckner@linux.vnet.ibm.com> | 2015-02-19 14:22:02 +0300 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-07-22 10:58:02 +0300 |
| commit | 8f00b3e28f73e712a2f82a15f66acd852f60e3ba (patch) | |
| tree | 52fe46682c01970f8750a32dead49d7861b91e6c | |
| parent | 7d0c502040a23a5924d3021651cf5326c8694a77 (diff) | |
| download | linux-8f00b3e28f73e712a2f82a15f66acd852f60e3ba.tar.xz | |
s390/module: enable generic CPU feature modalias using s390 ELF hwcaps
Add support for the generic CPU feature modalias implementation that wires
up optional CPU features to udev-based module autoprobing.
The <asm/cpufeature.h> file provides definitions to map CPU features to
s390 ELF hardware capabilities.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/Kconfig | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/cpufeature.h | 29 | ||||
| -rw-r--r-- | arch/s390/kernel/processor.c | 9 | ||||
| -rw-r--r-- | arch/s390/kernel/setup.c | 2 |
4 files changed, 40 insertions, 1 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index b06dc3839268..91e8954f1237 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -105,6 +105,7 @@ config S390 select CLONE_BACKWARDS2 select DYNAMIC_FTRACE if FUNCTION_TRACER select GENERIC_CLOCKEVENTS + select GENERIC_CPU_AUTOPROBE select GENERIC_CPU_DEVICES if !SMP select GENERIC_FIND_FIRST_BIT select GENERIC_SMP_IDLE_THREAD diff --git a/arch/s390/include/asm/cpufeature.h b/arch/s390/include/asm/cpufeature.h new file mode 100644 index 000000000000..fa7e69b7c299 --- /dev/null +++ b/arch/s390/include/asm/cpufeature.h @@ -0,0 +1,29 @@ +/* + * Module interface for CPU features + * + * Copyright IBM Corp. 2015 + * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> + */ + +#ifndef __ASM_S390_CPUFEATURE_H +#define __ASM_S390_CPUFEATURE_H + +#include <asm/elf.h> + +/* Hardware features on Linux on z Systems are indicated by facility bits that + * are mapped to the so-called machine flags. Particular machine flags are + * then used to define ELF hardware capabilities; most notably hardware flags + * that are essential for user space / glibc. + * + * Restrict the set of exposed CPU features to ELF hardware capabilities for + * now. Additional machine flags can be indicated by values larger than + * MAX_ELF_HWCAP_FEATURES. + */ +#define MAX_ELF_HWCAP_FEATURES (8 * sizeof(elf_hwcap)) +#define MAX_CPU_FEATURES MAX_ELF_HWCAP_FEATURES + +#define cpu_feature(feat) ilog2(HWCAP_S390_ ## feat) + +int cpu_have_feature(unsigned int nr); + +#endif /* __ASM_S390_CPUFEATURE_H */ diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c index dc488e13b7e3..e6e077ae3990 100644 --- a/arch/s390/kernel/processor.c +++ b/arch/s390/kernel/processor.c @@ -41,6 +41,15 @@ void cpu_init(void) } /* + * cpu_have_feature - Test CPU features on module initialization + */ +int cpu_have_feature(unsigned int num) +{ + return elf_hwcap & (1UL << num); +} +EXPORT_SYMBOL(cpu_have_feature); + +/* * show_cpuinfo - Get information on one CPU for use by procfs. */ static int show_cpuinfo(struct seq_file *m, void *v) diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index ca070d260af2..85a1d4770c9c 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -76,7 +76,7 @@ EXPORT_SYMBOL(console_devno); unsigned int console_irq = -1; EXPORT_SYMBOL(console_irq); -unsigned long elf_hwcap = 0; +unsigned long elf_hwcap __read_mostly = 0; char elf_platform[ELF_PLATFORM_SIZE]; int __initdata memory_end_set; |