arch/tile/include/asm/tlbflush.h

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #ifndef _ASM_TILE_TLBFLUSH_H
  16 #define _ASM_TILE_TLBFLUSH_H
  17
  18 #include <linux/mm.h>
  19 #include <linux/sched.h>
  20 #include <linux/smp.h>
  21 #include <asm/cacheflush.h>
  22 #include <asm/page.h>
  23 #include <hv/hypervisor.h>
  24
  25 /*
  26  * Rather than associating each mm with its own ASID, we just use
  27  * ASIDs to allow us to lazily flush the TLB when we switch mms.
  28  * This way we only have to do an actual TLB flush on mm switch
  29  * every time we wrap ASIDs, not every single time we switch.
  30  *
  31  * FIXME: We might improve performance by keeping ASIDs around
  32  * properly, though since the hypervisor direct-maps VAs to TSB
  33  * entries, we're likely to have lost at least the executable page
  34  * mappings by the time we switch back to the original mm.
  35  */
  36 DECLARE_PER_CPU(int, current_asid);
  37
  38 /* The hypervisor tells us what ASIDs are available to us. */
  39 extern int min_asid, max_asid;
  40
  41 static inline unsigned long hv_page_size(const struct vm_area_struct *vma)
  42 {
  43         return (vma->vm_flags & VM_HUGETLB) ? HPAGE_SIZE : PAGE_SIZE;
  44 }
  45
  46 /* Pass as vma pointer for non-executable mapping, if no vma available. */
  47 #define FLUSH_NONEXEC ((const struct vm_area_struct *)-1UL)
  48
  49 /* Flush a single user page on this cpu. */
  50 static inline void local_flush_tlb_page(const struct vm_area_struct *vma,
  51                                         unsigned long addr,
  52                                         unsigned long page_size)
  53 {
  54         int rc = hv_flush_page(addr, page_size);
  55         if (rc < 0)
  56                 panic("hv_flush_page(%#lx,%#lx) failed: %d",
  57                       addr, page_size, rc);
  58         if (!vma || (vma != FLUSH_NONEXEC && (vma->vm_flags & VM_EXEC)))
  59                 __flush_icache();
  60 }
  61
  62 /* Flush range of user pages on this cpu. */
  63 static inline void local_flush_tlb_pages(const struct vm_area_struct *vma,
  64                                          unsigned long addr,
  65                                          unsigned long page_size,
  66                                          unsigned long len)
  67 {
  68         int rc = hv_flush_pages(addr, page_size, len);
  69         if (rc < 0)
  70                 panic("hv_flush_pages(%#lx,%#lx,%#lx) failed: %d",
  71                       addr, page_size, len, rc);
  72         if (!vma || (vma != FLUSH_NONEXEC && (vma->vm_flags & VM_EXEC)))
  73                 __flush_icache();
  74 }
  75
  76 /* Flush all user pages on this cpu. */
  77 static inline void local_flush_tlb(void)
  78 {
  79         int rc = hv_flush_all(1);   /* preserve global mappings */
  80         if (rc < 0)
  81                 panic("hv_flush_all(1) failed: %d", rc);
  82         __flush_icache();
  83 }
  84
  85 /*
  86  * Global pages have to be flushed a bit differently. Not a real
  87  * performance problem because this does not happen often.
  88  */
  89 static inline void local_flush_tlb_all(void)
  90 {
  91         int i;
  92         for (i = 0; ; ++i) {
  93                 HV_VirtAddrRange r = hv_inquire_virtual(i);
  94                 if (r.size == 0)
  95                         break;
  96                 local_flush_tlb_pages(NULL, r.start, PAGE_SIZE, r.size);
  97                 local_flush_tlb_pages(NULL, r.start, HPAGE_SIZE, r.size);
  98         }
  99 }
 100
 101 /*
 102  * TLB flushing:
 103  *
 104  *  - flush_tlb() flushes the current mm struct TLBs
 105  *  - flush_tlb_all() flushes all processes TLBs
 106  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
 107  *  - flush_tlb_page(vma, vmaddr) flushes one page
 108  *  - flush_tlb_range(vma, start, end) flushes a range of pages
 109  *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
 110  *  - flush_tlb_others(cpumask, mm, va) flushes TLBs on other cpus
 111  *
 112  * Here (as in vm_area_struct), "end" means the first byte after
 113  * our end address.
 114  */
 115
 116 extern void flush_tlb_all(void);
 117 extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
 118 extern void flush_tlb_current_task(void);
 119 extern void flush_tlb_mm(struct mm_struct *);
 120 extern void flush_tlb_page(const struct vm_area_struct *, unsigned long);
 121 extern void flush_tlb_page_mm(const struct vm_area_struct *,
 122                               struct mm_struct *, unsigned long);
 123 extern void flush_tlb_range(const struct vm_area_struct *,
 124                             unsigned long start, unsigned long end);
 125
 126 #define flush_tlb()     flush_tlb_current_task()
 127
 128 #endif /* _ASM_TILE_TLBFLUSH_H */