Commit 80f06306 authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390/vdso: reimplement getcpu vdso syscall 



Implement the previously removed getcpu vdso syscall by using the
TOD programmable field to pass the cpu number to user space.

Reviewed-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 062e5279

arch/s390/include/asm/timex.h

+7 −0
Original line number Diff line number Diff line
@@ -49,6 +49,13 @@ static inline void set_clock_comparator(__u64 time) 
	asm volatile("sckc %0" : : "Q" (time));

}



static inline void set_tod_programmable_field(u16 val)

{

	register unsigned long reg0 asm("0") = val;



	asm volatile("sckpf" : : "d" (reg0));

}



void clock_comparator_work(void);



void __init time_early_init(void);

arch/s390/include/asm/vdso.h

+2 −0
Original line number Diff line number Diff line
@@ -14,5 +14,7 @@ 


extern struct vdso_data *vdso_data;



void vdso_getcpu_init(void);



#endif /* __ASSEMBLY__ */

#endif /* __S390_VDSO_H__ */

arch/s390/kernel/smp.c

+2 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ 
#include <asm/nmi.h>

#include <asm/stacktrace.h>

#include <asm/topology.h>

#include <asm/vdso.h>

#include "entry.h"



enum {
@@ -858,6 +859,7 @@ static void smp_init_secondary(void) 
	preempt_disable();

	init_cpu_timer();

	vtime_init();

	vdso_getcpu_init();

	pfault_init();

	notify_cpu_starting(cpu);

	if (topology_cpu_dedicated(cpu))

arch/s390/kernel/vdso.c

+7 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <asm/sections.h>

#include <asm/vdso.h>

#include <asm/facility.h>

#include <asm/timex.h>



extern char vdso64_start, vdso64_end;

static void *vdso64_kbase = &vdso64_start;
@@ -100,6 +101,11 @@ static union { 
} vdso_data_store __page_aligned_data;

struct vdso_data *vdso_data = (struct vdso_data *)&vdso_data_store.data;



void vdso_getcpu_init(void)

{

	set_tod_programmable_field(smp_processor_id());

}



/*

 * This is called from binfmt_elf, we create the special vma for the

 * vDSO and insert it into the mm struct tree
@@ -170,6 +176,7 @@ static int __init vdso_init(void) 
{

	int i;



	vdso_getcpu_init();

	/* Calculate the size of the 64 bit vDSO */

	vdso64_pages = ((&vdso64_end - &vdso64_start

			 + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;

arch/s390/kernel/vdso64/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -7,7 +7,8 @@ ARCH_REL_TYPE_ABS += R_390_GOT|R_390_PLT 


include $(srctree)/lib/vdso/Makefile

obj-vdso64 = vdso_user_wrapper.o note.o

obj-cvdso64 = vdso64_generic.o

obj-cvdso64 = vdso64_generic.o getcpu.o

CFLAGS_REMOVE_getcpu.o = -pg $(CC_FLAGS_FTRACE) $(CC_FLAGS_EXPOLINE)

CFLAGS_REMOVE_vdso64_generic.o = -pg $(CC_FLAGS_FTRACE) $(CC_FLAGS_EXPOLINE)



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