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/hugetlbpage.c | 5 +---- arch/s390/mm/init.c | 7 +++++-- arch/s390/mm/pgtable.c | 4 ++-- arch/s390/mm/vmem.c | 2 -- 4 files changed, 8 insertions(+), 10 deletions(-) (limited to 'arch/s390/mm') diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c index d261c62e40a6..0727a55d87d9 100644 --- a/arch/s390/mm/hugetlbpage.c +++ b/arch/s390/mm/hugetlbpage.c @@ -123,10 +123,7 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, pmd_t *pmdp = (pmd_t *) ptep; pte_t pte = huge_ptep_get(ptep); - if (MACHINE_HAS_IDTE) - __pmd_idte(addr, pmdp); - else - __pmd_csp(pmdp); + pmdp_flush_direct(mm, addr, pmdp); pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY; return pte; } diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index ad446b0c55b6..0c1073ed1e84 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -124,8 +124,6 @@ void __init paging_init(void) __ctl_load(S390_lowcore.kernel_asce, 13, 13); arch_local_irq_restore(4UL << (BITS_PER_LONG - 8)); - atomic_set(&init_mm.context.attach_count, 1); - sparse_memory_present_with_active_regions(MAX_NUMNODES); sparse_init(); memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); @@ -136,6 +134,11 @@ void __init paging_init(void) void __init mem_init(void) { + if (MACHINE_HAS_TLB_LC) + cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); + cpumask_set_cpu(0, mm_cpumask(&init_mm)); + atomic_set(&init_mm.context.attach_count, 1); + max_mapnr = max_low_pfn; high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 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(); diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index bcfb70b60be6..72b04de18283 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -138,7 +138,6 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro) } ret = 0; out: - flush_tlb_kernel_range(start, end); return ret; } @@ -265,7 +264,6 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) memset((void *)start, 0, end - start); ret = 0; out: - flush_tlb_kernel_range(start, end); return ret; } -- cgit v1.2.3