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| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-04-03 13:55:01 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-04-03 14:31:00 +0200 |
| commit | 1b948d6caec4f28e3524244ca0f77c6ae8ddceef (patch) | |
| tree | bc7e1d5800f10c39979d3f47872ba7047568f8a4 /arch/s390/mm/pgtable.c | |
| parent | s390/mm,tlb: safeguard against speculative TLB creation (diff) | |
| download | linux-dev-1b948d6caec4f28e3524244ca0f77c6ae8ddceef.tar.xz linux-dev-1b948d6caec4f28e3524244ca0f77c6ae8ddceef.zip | |
s390/mm,tlb: optimize TLB flushing for zEC12
The zEC12 machines introduced the local-clearing control for the IDTE
and IPTE instruction. If the control is set only the TLB of the local
CPU is cleared of entries, either all entries of a single address space
for IDTE, or the entry for a single page-table entry for IPTE.
Without the local-clearing control the TLB flush is broadcasted to all
CPUs in the configuration, which is expensive.
The reset of the bit mask of the CPUs that need flushing after a
non-local IDTE is tricky. As TLB entries for an address space remain
in the TLB even if the address space is detached a new bit field is
required to keep track of attached CPUs vs. CPUs in the need of a
flush. After a non-local flush with IDTE the bit-field of attached CPUs
is copied to the bit-field of CPUs in need of a flush. The ordering
of operations on cpu_attach_mask, attach_count and mm_cpumask(mm) is
such that an underindication in mm_cpumask(mm) is prevented but an
overindication in mm_cpumask(mm) is possible.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm/pgtable.c')
| -rw-r--r-- | arch/s390/mm/pgtable.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 24c62900b532..c57c63380184 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -200,7 +200,7 @@ static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table) static void gmap_flush_tlb(struct gmap *gmap) { if (MACHINE_HAS_IDTE) - __tlb_flush_idte((unsigned long) gmap->table | + __tlb_flush_asce(gmap->mm, (unsigned long) gmap->table | _ASCE_TYPE_REGION1); else __tlb_flush_global(); @@ -219,7 +219,7 @@ void gmap_free(struct gmap *gmap) /* Flush tlb. */ if (MACHINE_HAS_IDTE) - __tlb_flush_idte((unsigned long) gmap->table | + __tlb_flush_asce(gmap->mm, (unsigned long) gmap->table | _ASCE_TYPE_REGION1); else __tlb_flush_global(); |