LXR linux/arch/parisc/include/asm/tlbflush.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _PARISC_TLBFLUSH_H
   3#define _PARISC_TLBFLUSH_H
   4
   5/* TLB flushing routines.... */
   6
   7#include <linux/mm.h>
   8#include <linux/sched.h>
   9#include <asm/mmu_context.h>
  10
  11
  12/* This is for the serialisation of PxTLB broadcasts.  At least on the
  13 * N class systems, only one PxTLB inter processor broadcast can be
  14 * active at any one time on the Merced bus.  This tlb purge
  15 * synchronisation is fairly lightweight and harmless so we activate
  16 * it on all systems not just the N class.
  17
  18 * It is also used to ensure PTE updates are atomic and consistent
  19 * with the TLB.
  20 */
  21extern spinlock_t pa_tlb_lock;
  22
  23#define purge_tlb_start(flags)  spin_lock_irqsave(&pa_tlb_lock, flags)
  24#define purge_tlb_end(flags)    spin_unlock_irqrestore(&pa_tlb_lock, flags)
  25
  26extern void flush_tlb_all(void);
  27extern void flush_tlb_all_local(void *);
  28
  29#define smp_flush_tlb_all()     flush_tlb_all()
  30
  31int __flush_tlb_range(unsigned long sid,
  32        unsigned long start, unsigned long end);
  33
  34#define flush_tlb_range(vma, start, end) \
  35        __flush_tlb_range((vma)->vm_mm->context, start, end)
  36
  37#define flush_tlb_kernel_range(start, end) \
  38        __flush_tlb_range(0, start, end)
  39
  40/*
  41 * flush_tlb_mm()
  42 *
  43 * The code to switch to a new context is NOT valid for processes
  44 * which play with the space id's.  Thus, we have to preserve the
  45 * space and just flush the entire tlb.  However, the compilers,
  46 * dynamic linker, etc, do not manipulate space id's, so there
  47 * could be a significant performance benefit in switching contexts
  48 * and not flushing the whole tlb.
  49 */
  50
  51static inline void flush_tlb_mm(struct mm_struct *mm)
  52{
  53        BUG_ON(mm == &init_mm); /* Should never happen */
  54
  55#if 1 || defined(CONFIG_SMP)
  56        /* Except for very small threads, flushing the whole TLB is
  57         * faster than using __flush_tlb_range.  The pdtlb and pitlb
  58         * instructions are very slow because of the TLB broadcast.
  59         * It might be faster to do local range flushes on all CPUs
  60         * on PA 2.0 systems.
  61         */
  62        flush_tlb_all();
  63#else
  64        /* FIXME: currently broken, causing space id and protection ids
  65         * to go out of sync, resulting in faults on userspace accesses.
  66         * This approach needs further investigation since running many
  67         * small applications (e.g., GCC testsuite) is faster on HP-UX.
  68         */
  69        if (mm) {
  70                if (mm->context != 0)
  71                        free_sid(mm->context);
  72                mm->context = alloc_sid();
  73                if (mm == current->active_mm)
  74                        load_context(mm->context);
  75        }
  76#endif
  77}
  78
  79static inline void flush_tlb_page(struct vm_area_struct *vma,
  80        unsigned long addr)
  81{
  82        unsigned long flags, sid;
  83
  84        sid = vma->vm_mm->context;
  85        purge_tlb_start(flags);
  86        mtsp(sid, 1);
  87        pdtlb(addr);
  88        if (unlikely(split_tlb))
  89                pitlb(addr);
  90        purge_tlb_end(flags);
  91}
  92#endif
  93