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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-01-05 13:29:38 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-01-11 13:01:24 +0100 |
| commit | 249c543b97e1409b13fb9539b2f880e58ddd87cf (patch) | |
| tree | 956a0719238b56b8dffa3877d3fe3eb5c27df9f4 /arch/s390/kernel/vdso.c | |
| parent | 0dab3e0e59ac3692e2f95cb37ba17d5dfb3d1e5f (diff) | |
| download | linux-249c543b97e1409b13fb9539b2f880e58ddd87cf.tar.bz2 | |
s390/vdso: optimize getcpu system call
Add the CPU number to the per-cpu vdso data page and add the
__kernel_getcpu function to the vdso object to retrieve the
CPU number in user space.
Suggested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/vdso.c')
| -rw-r--r-- | arch/s390/kernel/vdso.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index 604f4a68b524..94495cac8be3 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -80,7 +80,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data; /* * Setup vdso data page. */ -static void vdso_init_data(struct vdso_data *vd) +static void __init vdso_init_data(struct vdso_data *vd) { vd->ectg_available = test_facility(31); } @@ -93,6 +93,7 @@ static void vdso_init_data(struct vdso_data *vd) int vdso_alloc_per_cpu(struct lowcore *lowcore) { unsigned long segment_table, page_table, page_frame; + struct vdso_per_cpu_data *vd; u32 *psal, *aste; int i; @@ -107,6 +108,12 @@ int vdso_alloc_per_cpu(struct lowcore *lowcore) if (!segment_table || !page_table || !page_frame) goto out; + /* Initialize per-cpu vdso data page */ + vd = (struct vdso_per_cpu_data *) page_frame; + vd->cpu_nr = lowcore->cpu_nr; + vd->node_id = cpu_to_node(vd->cpu_nr); + + /* Set up access register mode page table */ clear_table((unsigned long *) segment_table, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE << SEGMENT_ORDER); clear_table((unsigned long *) page_table, _PAGE_INVALID, |