arch/ia64/mm/tlb.c

   1 /*
   2  * TLB support routines.
   3  *
   4  * Copyright (C) 1998-2001, 2003 Hewlett-Packard Co
   5  *      David Mosberger-Tang <davidm@hpl.hp.com>
   6  *
   7  * 08/02/00 A. Mallick <asit.k.mallick@intel.com>
   8  *              Modified RID allocation for SMP
   9  *          Goutham Rao <goutham.rao@intel.com>
  10  *              IPI based ptc implementation and A-step IPI implementation.
  11  * Rohit Seth <rohit.seth@intel.com>
  12  * Ken Chen <kenneth.w.chen@intel.com>
  13  */
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/sched.h>
  18 #include <linux/smp.h>
  19 #include <linux/mm.h>
  20 #include <linux/bootmem.h>
  21
  22 #include <asm/delay.h>
  23 #include <asm/mmu_context.h>
  24 #include <asm/pgalloc.h>
  25 #include <asm/pal.h>
  26 #include <asm/tlbflush.h>
  27 #include <asm/dma.h>
  28
  29 static struct {
  30         unsigned long mask;     /* mask of supported purge page-sizes */
  31         unsigned long max_bits; /* log2 of largest supported purge page-size */
  32 } purge;
  33
  34 struct ia64_ctx ia64_ctx = {
  35         .lock = __SPIN_LOCK_UNLOCKED(ia64_ctx.lock),
  36         .next = 1,
  37         .max_ctx = ~0U
  38 };
  39
  40 DEFINE_PER_CPU(u8, ia64_need_tlb_flush);
  41
  42 /*
  43  * Initializes the ia64_ctx.bitmap array based on max_ctx+1.
  44  * Called after cpu_init() has setup ia64_ctx.max_ctx based on
  45  * maximum RID that is supported by boot CPU.
  46  */
  47 void __init
  48 mmu_context_init (void)
  49 {
  50         ia64_ctx.bitmap = alloc_bootmem((ia64_ctx.max_ctx+1)>>3);
  51         ia64_ctx.flushmap = alloc_bootmem((ia64_ctx.max_ctx+1)>>3);
  52 }
  53
  54 /*
  55  * Acquire the ia64_ctx.lock before calling this function!
  56  */
  57 void
  58 wrap_mmu_context (struct mm_struct *mm)
  59 {
  60         int i, cpu;
  61         unsigned long flush_bit;
  62
  63         for (i=0; i <= ia64_ctx.max_ctx / BITS_PER_LONG; i++) {
  64                 flush_bit = xchg(&ia64_ctx.flushmap[i], 0);
  65                 ia64_ctx.bitmap[i] ^= flush_bit;
  66         }
  67
  68         /* use offset at 300 to skip daemons */
  69         ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap,
  70                                 ia64_ctx.max_ctx, 300);
  71         ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap,
  72                                 ia64_ctx.max_ctx, ia64_ctx.next);
  73
  74         /*
  75          * can't call flush_tlb_all() here because of race condition
  76          * with O(1) scheduler [EF]
  77          */
  78         cpu = get_cpu(); /* prevent preemption/migration */
  79         for_each_online_cpu(i)
  80                 if (i != cpu)
  81                         per_cpu(ia64_need_tlb_flush, i) = 1;
  82         put_cpu();
  83         local_flush_tlb_all();
  84 }
  85
  86 void
  87 ia64_global_tlb_purge (struct mm_struct *mm, unsigned long start,
  88                        unsigned long end, unsigned long nbits)
  89 {
  90         static DEFINE_SPINLOCK(ptcg_lock);
  91
  92         if (mm != current->active_mm || !current->mm) {
  93                 flush_tlb_all();
  94                 return;
  95         }
  96
  97         /* HW requires global serialization of ptc.ga.  */
  98         spin_lock(&ptcg_lock);
  99         {
 100                 do {
 101                         /*
 102                          * Flush ALAT entries also.
 103                          */
 104                         ia64_ptcga(start, (nbits<<2));
 105                         ia64_srlz_i();
 106                         start += (1UL << nbits);
 107                 } while (start < end);
 108         }
 109         spin_unlock(&ptcg_lock);
 110 }
 111
 112 void
 113 local_flush_tlb_all (void)
 114 {
 115         unsigned long i, j, flags, count0, count1, stride0, stride1, addr;
 116
 117         addr    = local_cpu_data->ptce_base;
 118         count0  = local_cpu_data->ptce_count[0];
 119         count1  = local_cpu_data->ptce_count[1];
 120         stride0 = local_cpu_data->ptce_stride[0];
 121         stride1 = local_cpu_data->ptce_stride[1];
 122
 123         local_irq_save(flags);
 124         for (i = 0; i < count0; ++i) {
 125                 for (j = 0; j < count1; ++j) {
 126                         ia64_ptce(addr);
 127                         addr += stride1;
 128                 }
 129                 addr += stride0;
 130         }
 131         local_irq_restore(flags);
 132         ia64_srlz_i();                  /* srlz.i implies srlz.d */
 133 }
 134
 135 void
 136 flush_tlb_range (struct vm_area_struct *vma, unsigned long start,
 137                  unsigned long end)
 138 {
 139         struct mm_struct *mm = vma->vm_mm;
 140         unsigned long size = end - start;
 141         unsigned long nbits;
 142
 143 #ifndef CONFIG_SMP
 144         if (mm != current->active_mm) {
 145                 mm->context = 0;
 146                 return;
 147         }
 148 #endif
 149
 150         nbits = ia64_fls(size + 0xfff);
 151         while (unlikely (((1UL << nbits) & purge.mask) == 0) &&
 152                         (nbits < purge.max_bits))
 153                 ++nbits;
 154         if (nbits > purge.max_bits)
 155                 nbits = purge.max_bits;
 156         start &= ~((1UL << nbits) - 1);
 157
 158         preempt_disable();
 159 #ifdef CONFIG_SMP
 160         if (mm != current->active_mm || cpus_weight(mm->cpu_vm_mask) != 1) {
 161                 platform_global_tlb_purge(mm, start, end, nbits);
 162                 preempt_enable();
 163                 return;
 164         }
 165 #endif
 166         do {
 167                 ia64_ptcl(start, (nbits<<2));
 168                 start += (1UL << nbits);
 169         } while (start < end);
 170         preempt_enable();
 171         ia64_srlz_i();                  /* srlz.i implies srlz.d */
 172 }
 173 EXPORT_SYMBOL(flush_tlb_range);
 174
 175 void __devinit
 176 ia64_tlb_init (void)
 177 {
 178         ia64_ptce_info_t uninitialized_var(ptce_info); /* GCC be quiet */
 179         unsigned long tr_pgbits;
 180         long status;
 181
 182         if ((status = ia64_pal_vm_page_size(&tr_pgbits, &purge.mask)) != 0) {
 183                 printk(KERN_ERR "PAL_VM_PAGE_SIZE failed with status=%ld;"
 184                        "defaulting to architected purge page-sizes.\n", status);
 185                 purge.mask = 0x115557000UL;
 186         }
 187         purge.max_bits = ia64_fls(purge.mask);
 188
 189         ia64_get_ptce(&ptce_info);
 190         local_cpu_data->ptce_base = ptce_info.base;
 191         local_cpu_data->ptce_count[0] = ptce_info.count[0];
 192         local_cpu_data->ptce_count[1] = ptce_info.count[1];
 193         local_cpu_data->ptce_stride[0] = ptce_info.stride[0];
 194         local_cpu_data->ptce_stride[1] = ptce_info.stride[1];
 195
 196         local_flush_tlb_all();  /* nuke left overs from bootstrapping... */
 197 }