tlbflush.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _S390_TLBFLUSH_H
  3#define _S390_TLBFLUSH_H
  4
  5#include <linux/cpufeature.h>
  6#include <linux/mm.h>
  7#include <linux/sched.h>
  8#include <asm/processor.h>
  9#include <asm/machine.h>
 10
 11/*
 12 * Flush all TLB entries on the local CPU.
 13 */
 14static inline void __tlb_flush_local(void)
 15{
 16	asm volatile("ptlb" : : : "memory");
 17}
 18
 19/*
 20 * Flush TLB entries for a specific ASCE on all CPUs
 21 */
 22static inline void __tlb_flush_idte(unsigned long asce)
 23{
 24	unsigned long opt;
 25
 26	opt = IDTE_PTOA;
 27	if (machine_has_tlb_guest())
 28		opt |= IDTE_GUEST_ASCE;
 29	/* Global TLB flush for the mm */
 30	asm volatile("idte 0,%1,%0" : : "a" (opt), "a" (asce) : "cc");
 31}
 32
 33/*
 34 * Flush all TLB entries on all CPUs.
 35 */
 36static inline void __tlb_flush_global(void)
 37{
 38	unsigned long dummy = 0;
 39
 40	cspg(&dummy, 0, 0);
 41}
 42
 43/*
 44 * Flush TLB entries for a specific mm on all CPUs (in case gmap is used
 45 * this implicates multiple ASCEs!).
 46 */
 47static inline void __tlb_flush_mm(struct mm_struct *mm)
 48{
 49	unsigned long gmap_asce;
 50
 51	preempt_disable();
 52	atomic_inc(&mm->context.flush_count);
 53	/* Reset TLB flush mask */
 54	cpumask_copy(mm_cpumask(mm), &mm->context.cpu_attach_mask);
 55	barrier();
 56	gmap_asce = READ_ONCE(mm->context.gmap_asce);
 57	if (gmap_asce != -1UL) {
 58		if (gmap_asce)
 59			__tlb_flush_idte(gmap_asce);
 60		__tlb_flush_idte(mm->context.asce);
 61	} else {
 62		/* Global TLB flush */
 63		__tlb_flush_global();
 64	}
 65	atomic_dec(&mm->context.flush_count);
 66	preempt_enable();
 67}
 68
 69static inline void __tlb_flush_kernel(void)
 70{
 71	__tlb_flush_idte(init_mm.context.asce);
 72}
 73
 74static inline void __tlb_flush_mm_lazy(struct mm_struct * mm)
 75{
 76	spin_lock(&mm->context.lock);
 77	if (mm->context.flush_mm) {
 78		mm->context.flush_mm = 0;
 79		__tlb_flush_mm(mm);
 80	}
 81	spin_unlock(&mm->context.lock);
 82}
 83
 84/*
 85 * TLB flushing:
 86 *  flush_tlb_all() - flushes all processes TLBs
 87 *  flush_tlb_mm(mm) - flushes the specified mm context TLB's
 88 *  flush_tlb_page(vma, vmaddr) - flushes one page
 89 *  flush_tlb_range(vma, start, end) - flushes a range of pages
 90 *  flush_tlb_kernel_range(start, end) - flushes a range of kernel pages
 91 */
 92
 93/*
 94 * flush_tlb_mm goes together with ptep_set_wrprotect for the
 95 * copy_page_range operation and flush_tlb_range is related to
 96 * ptep_get_and_clear for change_protection. ptep_set_wrprotect and
 97 * ptep_get_and_clear do not flush the TLBs directly if the mm has
 98 * only one user. At the end of the update the flush_tlb_mm and
 99 * flush_tlb_range functions need to do the flush.
100 */
101#define flush_tlb_all()				do { } while (0)
102#define flush_tlb_page(vma, addr)		do { } while (0)
103
104static inline void flush_tlb_mm(struct mm_struct *mm)
105{
106	__tlb_flush_mm_lazy(mm);
107}
108
109static inline void flush_tlb_range(struct vm_area_struct *vma,
110				   unsigned long start, unsigned long end)
111{
112	__tlb_flush_mm_lazy(vma->vm_mm);
113}
114
115static inline void flush_tlb_kernel_range(unsigned long start,
116					  unsigned long end)
117{
118	__tlb_flush_kernel();
119}
120
121#endif /* _S390_TLBFLUSH_H */