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Commit 8f00b3e2 authored by Hendrik Brueckner's avatar Hendrik Brueckner Committed by Martin Schwidefsky
Browse files

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: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 7d0c5020

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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

arch/s390/include/asm/cpufeature.h

0 → 100644
+29 −0
Original line number Diff line number Diff line 
/*

 * 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 */

arch/s390/kernel/processor.c

+9 −0
Original line number Diff line number Diff line
@@ -40,6 +40,15 @@ void cpu_init(void) 
	enter_lazy_tlb(&init_mm, current);

}



/*

 * 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.

 */

arch/s390/kernel/setup.c

+1 −1
Original line number Diff line number Diff line
@@ -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;