LXR linux/arch/tile/mm/migrate

   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 * This routine is a helper for migrating the home of a set of pages to
  15 * a new cpu.  See the documentation in homecache.c for more information.
  16 */
  17
  18#include <linux/linkage.h>
  19#include <linux/threads.h>
  20#include <asm/page.h>
  21#include <asm/thread_info.h>
  22#include <asm/types.h>
  23#include <asm/asm-offsets.h>
  24#include <hv/hypervisor.h>
  25
  26        .text
  27
  28/*
  29 * First, some definitions that apply to all the code in the file.
  30 */
  31
  32/* Locals (caller-save) */
  33#define r_tmp           r10
  34#define r_save_sp       r11
  35
  36/* What we save where in the stack frame; must include all callee-saves. */
  37#define FRAME_SP        4
  38#define FRAME_R30       8
  39#define FRAME_R31       12
  40#define FRAME_R32       16
  41#define FRAME_R33       20
  42#define FRAME_R34       24
  43#define FRAME_SIZE      28
  44
  45
  46
  47
  48/*
  49 * On entry:
  50 *
  51 *   r0 low word of the new context PA to install (moved to r_context_lo)
  52 *   r1 high word of the new context PA to install (moved to r_context_hi)
  53 *   r2 low word of PTE to use for context access (moved to r_access_lo)
  54 *   r3 high word of PTE to use for context access (moved to r_access_lo)
  55 *   r4 ASID to use for new context (moved to r_asid)
  56 *   r5 pointer to cpumask with just this cpu set in it (r_my_cpumask)
  57 */
  58
  59/* Arguments (caller-save) */
  60#define r_context_lo_in r0
  61#define r_context_hi_in r1
  62#define r_access_lo_in  r2
  63#define r_access_hi_in  r3
  64#define r_asid_in       r4
  65#define r_my_cpumask    r5
  66
  67/* Locals (callee-save); must not be more than FRAME_xxx above. */
  68#define r_context_lo    r30
  69#define r_context_hi    r31
  70#define r_access_lo     r32
  71#define r_access_hi     r33
  72#define r_asid          r34
  73
  74STD_ENTRY(flush_and_install_context)
  75        /*
  76         * Create a stack frame; we can't touch it once we flush the
  77         * cache until we install the new page table and flush the TLB.
  78         */
  79        {
  80         move r_save_sp, sp
  81         sw sp, lr
  82         addi sp, sp, -FRAME_SIZE
  83        }
  84        addi r_tmp, sp, FRAME_SP
  85        {
  86         sw r_tmp, r_save_sp
  87         addi r_tmp, sp, FRAME_R30
  88        }
  89        {
  90         sw r_tmp, r30
  91         addi r_tmp, sp, FRAME_R31
  92        }
  93        {
  94         sw r_tmp, r31
  95         addi r_tmp, sp, FRAME_R32
  96        }
  97        {
  98         sw r_tmp, r32
  99         addi r_tmp, sp, FRAME_R33
 100        }
 101        {
 102         sw r_tmp, r33
 103         addi r_tmp, sp, FRAME_R34
 104        }
 105        sw r_tmp, r34
 106
 107        /* Move some arguments to callee-save registers. */
 108        {
 109         move r_context_lo, r_context_lo_in
 110         move r_context_hi, r_context_hi_in
 111        }
 112        {
 113         move r_access_lo, r_access_lo_in
 114         move r_access_hi, r_access_hi_in
 115        }
 116        move r_asid, r_asid_in
 117
 118        /* First, flush our L2 cache. */
 119        {
 120         move r0, zero  /* cache_pa */
 121         move r1, zero
 122        }
 123        {
 124         auli r2, zero, ha16(HV_FLUSH_EVICT_L2)  /* cache_control */
 125         move r3, r_my_cpumask  /* cache_cpumask */
 126        }
 127        {
 128         move r4, zero  /* tlb_va */
 129         move r5, zero  /* tlb_length */
 130        }
 131        {
 132         move r6, zero  /* tlb_pgsize */
 133         move r7, zero  /* tlb_cpumask */
 134        }
 135        {
 136         move r8, zero  /* asids */
 137         move r9, zero  /* asidcount */
 138        }
 139        jal _hv_flush_remote
 140        bnz r0, .Ldone
 141
 142        /* Now install the new page table. */
 143        {
 144         move r0, r_context_lo
 145         move r1, r_context_hi
 146        }
 147        {
 148         move r2, r_access_lo
 149         move r3, r_access_hi
 150        }
 151        {
 152         move r4, r_asid
 153         moveli r5, HV_CTX_DIRECTIO | CTX_PAGE_FLAG
 154        }
 155        jal _hv_install_context
 156        bnz r0, .Ldone
 157
 158        /* Finally, flush the TLB. */
 159        {
 160         movei r0, 0   /* preserve_global */
 161         jal hv_flush_all
 162        }
 163
 164.Ldone:
 165        /* Restore the callee-saved registers and return. */
 166        addli lr, sp, FRAME_SIZE
 167        {
 168         lw lr, lr
 169         addli r_tmp, sp, FRAME_R30
 170        }
 171        {
 172         lw r30, r_tmp
 173         addli r_tmp, sp, FRAME_R31
 174        }
 175        {
 176         lw r31, r_tmp
 177         addli r_tmp, sp, FRAME_R32
 178        }
 179        {
 180         lw r32, r_tmp
 181         addli r_tmp, sp, FRAME_R33
 182        }
 183        {
 184         lw r33, r_tmp
 185         addli r_tmp, sp, FRAME_R34
 186        }
 187        {
 188         lw r34, r_tmp
 189         addi sp, sp, FRAME_SIZE
 190        }
 191        jrp lr
 192        STD_ENDPROC(flush_and_install_context)
 193