From 1b948d6caec4f28e3524244ca0f77c6ae8ddceef Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 3 Apr 2014 13:55:01 +0200 Subject: 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 --- arch/s390/mm/pgtable.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/s390/mm/pgtable.c') 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(); -- cgit v1.2.3