include/asm-s390/tlbflush.h

   1 #ifndef _S390_TLBFLUSH_H
   2 #define _S390_TLBFLUSH_H
   3
   4 #include <linux/mm.h>
   5 #include <asm/processor.h>
   6 #include <asm/pgalloc.h>
   7
   8 /*
   9  * Flush all tlb entries on the local cpu.
  10  */
  11 static inline void __tlb_flush_local(void)
  12 {
  13         asm volatile("ptlb" : : : "memory");
  14 }
  15
  16 /*
  17  * Flush all tlb entries on all cpus.
  18  */
  19 static inline void __tlb_flush_global(void)
  20 {
  21         extern void smp_ptlb_all(void);
  22         register unsigned long reg2 asm("2");
  23         register unsigned long reg3 asm("3");
  24         register unsigned long reg4 asm("4");
  25         long dummy;
  26
  27 #ifndef __s390x__
  28         if (!MACHINE_HAS_CSP) {
  29                 smp_ptlb_all();
  30                 return;
  31         }
  32 #endif /* __s390x__ */
  33
  34         dummy = 0;
  35         reg2 = reg3 = 0;
  36         reg4 = ((unsigned long) &dummy) + 1;
  37         asm volatile(
  38                 "       csp     %0,%2"
  39                 : : "d" (reg2), "d" (reg3), "d" (reg4), "m" (dummy) : "cc" );
  40 }
  41
  42 /*
  43  * Flush all tlb entries of a page table on all cpus.
  44  */
  45 static inline void __tlb_flush_idte(pgd_t *pgd)
  46 {
  47         asm volatile(
  48                 "       .insn   rrf,0xb98e0000,0,%0,%1,0"
  49                 : : "a" (2048), "a" (__pa(pgd) & PAGE_MASK) : "cc" );
  50 }
  51
  52 static inline void __tlb_flush_mm(struct mm_struct * mm)
  53 {
  54         cpumask_t local_cpumask;
  55
  56         if (unlikely(cpus_empty(mm->cpu_vm_mask)))
  57                 return;
  58         /*
  59          * If the machine has IDTE we prefer to do a per mm flush
  60          * on all cpus instead of doing a local flush if the mm
  61          * only ran on the local cpu.
  62          */
  63         if (MACHINE_HAS_IDTE) {
  64                 pgd_t *shadow_pgd = get_shadow_table(mm->pgd);
  65
  66                 if (shadow_pgd)
  67                         __tlb_flush_idte(shadow_pgd);
  68                 __tlb_flush_idte(mm->pgd);
  69                 return;
  70         }
  71         preempt_disable();
  72         /*
  73          * If the process only ran on the local cpu, do a local flush.
  74          */
  75         local_cpumask = cpumask_of_cpu(smp_processor_id());
  76         if (cpus_equal(mm->cpu_vm_mask, local_cpumask))
  77                 __tlb_flush_local();
  78         else
  79                 __tlb_flush_global();
  80         preempt_enable();
  81 }
  82
  83 static inline void __tlb_flush_mm_cond(struct mm_struct * mm)
  84 {
  85         if (atomic_read(&mm->mm_users) <= 1 && mm == current->active_mm)
  86                 __tlb_flush_mm(mm);
  87 }
  88
  89 /*
  90  * TLB flushing:
  91  *  flush_tlb() - flushes the current mm struct TLBs
  92  *  flush_tlb_all() - flushes all processes TLBs
  93  *  flush_tlb_mm(mm) - flushes the specified mm context TLB's
  94  *  flush_tlb_page(vma, vmaddr) - flushes one page
  95  *  flush_tlb_range(vma, start, end) - flushes a range of pages
  96  *  flush_tlb_kernel_range(start, end) - flushes a range of kernel pages
  97  */
  98
  99 /*
 100  * flush_tlb_mm goes together with ptep_set_wrprotect for the
 101  * copy_page_range operation and flush_tlb_range is related to
 102  * ptep_get_and_clear for change_protection. ptep_set_wrprotect and
 103  * ptep_get_and_clear do not flush the TLBs directly if the mm has
 104  * only one user. At the end of the update the flush_tlb_mm and
 105  * flush_tlb_range functions need to do the flush.
 106  */
 107 #define flush_tlb()                             do { } while (0)
 108 #define flush_tlb_all()                         do { } while (0)
 109 #define flush_tlb_mm(mm)                        __tlb_flush_mm_cond(mm)
 110 #define flush_tlb_page(vma, addr)               do { } while (0)
 111 #define flush_tlb_range(vma, start, end)        __tlb_flush_mm_cond(mm)
 112 #define flush_tlb_kernel_range(start, end)      __tlb_flush_mm(&init_mm)
 113
 114 #endif /* _S390_TLBFLUSH_H */