arch/powerpc/mm/fsl_booke_mmu.c

   1 /*
   2  * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
   3  * E500 Book E processors.
   4  *
   5  * Copyright 2004 Freescale Semiconductor, Inc
   6  *
   7  * This file contains the routines for initializing the MMU
   8  * on the 4xx series of chips.
   9  *  -- paulus
  10  *
  11  *  Derived from arch/ppc/mm/init.c:
  12  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  13  *
  14  *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
  15  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
  16  *    Copyright (C) 1996 Paul Mackerras
  17  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
  18  *
  19  *  Derived from "arch/i386/mm/init.c"
  20  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  21  *
  22  *  This program is free software; you can redistribute it and/or
  23  *  modify it under the terms of the GNU General Public License
  24  *  as published by the Free Software Foundation; either version
  25  *  2 of the License, or (at your option) any later version.
  26  *
  27  */
  28
  29 #include <linux/config.h>
  30 #include <linux/signal.h>
  31 #include <linux/sched.h>
  32 #include <linux/kernel.h>
  33 #include <linux/errno.h>
  34 #include <linux/string.h>
  35 #include <linux/types.h>
  36 #include <linux/ptrace.h>
  37 #include <linux/mman.h>
  38 #include <linux/mm.h>
  39 #include <linux/swap.h>
  40 #include <linux/stddef.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/init.h>
  43 #include <linux/delay.h>
  44 #include <linux/highmem.h>
  45
  46 #include <asm/pgalloc.h>
  47 #include <asm/prom.h>
  48 #include <asm/io.h>
  49 #include <asm/mmu_context.h>
  50 #include <asm/pgtable.h>
  51 #include <asm/mmu.h>
  52 #include <asm/uaccess.h>
  53 #include <asm/smp.h>
  54 #include <asm/bootx.h>
  55 #include <asm/machdep.h>
  56 #include <asm/setup.h>
  57
  58 extern void loadcam_entry(unsigned int index);
  59 unsigned int tlbcam_index;
  60 unsigned int num_tlbcam_entries;
  61 static unsigned long __cam0, __cam1, __cam2;
  62 extern unsigned long total_lowmem;
  63 extern unsigned long __max_low_memory;
  64 #define MAX_LOW_MEM     CONFIG_LOWMEM_SIZE
  65
  66 #define NUM_TLBCAMS     (16)
  67
  68 struct tlbcam {
  69         u32     MAS0;
  70         u32     MAS1;
  71         u32     MAS2;
  72         u32     MAS3;
  73         u32     MAS7;
  74 } TLBCAM[NUM_TLBCAMS];
  75
  76 struct tlbcamrange {
  77         unsigned long start;
  78         unsigned long limit;
  79         phys_addr_t phys;
  80 } tlbcam_addrs[NUM_TLBCAMS];
  81
  82 extern unsigned int tlbcam_index;
  83
  84 /*
  85  * Return PA for this VA if it is mapped by a CAM, or 0
  86  */
  87 unsigned long v_mapped_by_tlbcam(unsigned long va)
  88 {
  89         int b;
  90         for (b = 0; b < tlbcam_index; ++b)
  91                 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
  92                         return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
  93         return 0;
  94 }
  95
  96 /*
  97  * Return VA for a given PA or 0 if not mapped
  98  */
  99 unsigned long p_mapped_by_tlbcam(unsigned long pa)
 100 {
 101         int b;
 102         for (b = 0; b < tlbcam_index; ++b)
 103                 if (pa >= tlbcam_addrs[b].phys
 104                     && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
 105                               +tlbcam_addrs[b].phys)
 106                         return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
 107         return 0;
 108 }
 109
 110 /*
 111  * Set up one of the I/D BAT (block address translation) register pairs.
 112  * The parameters are not checked; in particular size must be a power
 113  * of 4 between 4k and 256M.
 114  */
 115 void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 116                 unsigned int size, int flags, unsigned int pid)
 117 {
 118         unsigned int tsize, lz;
 119
 120         asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));
 121         tsize = (21 - lz) / 2;
 122
 123 #ifdef CONFIG_SMP
 124         if ((flags & _PAGE_NO_CACHE) == 0)
 125                 flags |= _PAGE_COHERENT;
 126 #endif
 127
 128         TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
 129         TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
 130         TLBCAM[index].MAS2 = virt & PAGE_MASK;
 131
 132         TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
 133         TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
 134         TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
 135         TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
 136         TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
 137
 138         TLBCAM[index].MAS3 = (phys & PAGE_MASK) | MAS3_SX | MAS3_SR;
 139         TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 140
 141 #ifndef CONFIG_KGDB /* want user access for breakpoints */
 142         if (flags & _PAGE_USER) {
 143            TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 144            TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 145         }
 146 #else
 147         TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 148         TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 149 #endif
 150
 151         tlbcam_addrs[index].start = virt;
 152         tlbcam_addrs[index].limit = virt + size - 1;
 153         tlbcam_addrs[index].phys = phys;
 154
 155         loadcam_entry(index);
 156 }
 157
 158 void invalidate_tlbcam_entry(int index)
 159 {
 160         TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index);
 161         TLBCAM[index].MAS1 = ~MAS1_VALID;
 162
 163         loadcam_entry(index);
 164 }
 165
 166 void __init cam_mapin_ram(unsigned long cam0, unsigned long cam1,
 167                 unsigned long cam2)
 168 {
 169         settlbcam(0, KERNELBASE, PPC_MEMSTART, cam0, _PAGE_KERNEL, 0);
 170         tlbcam_index++;
 171         if (cam1) {
 172                 tlbcam_index++;
 173                 settlbcam(1, KERNELBASE+cam0, PPC_MEMSTART+cam0, cam1, _PAGE_KERNEL, 0);
 174         }
 175         if (cam2) {
 176                 tlbcam_index++;
 177                 settlbcam(2, KERNELBASE+cam0+cam1, PPC_MEMSTART+cam0+cam1, cam2, _PAGE_KERNEL, 0);
 178         }
 179 }
 180
 181 /*
 182  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 183  */
 184 void __init MMU_init_hw(void)
 185 {
 186         flush_instruction_cache();
 187 }
 188
 189 unsigned long __init mmu_mapin_ram(void)
 190 {
 191         cam_mapin_ram(__cam0, __cam1, __cam2);
 192
 193         return __cam0 + __cam1 + __cam2;
 194 }
 195
 196
 197 void __init
 198 adjust_total_lowmem(void)
 199 {
 200         unsigned long max_low_mem = MAX_LOW_MEM;
 201         unsigned long cam_max = 0x10000000;
 202         unsigned long ram;
 203
 204         /* adjust CAM size to max_low_mem */
 205         if (max_low_mem < cam_max)
 206                 cam_max = max_low_mem;
 207
 208         /* adjust lowmem size to max_low_mem */
 209         if (max_low_mem < total_lowmem)
 210                 ram = max_low_mem;
 211         else
 212                 ram = total_lowmem;
 213
 214         /* Calculate CAM values */
 215         __cam0 = 1UL << 2 * (__ilog2(ram) / 2);
 216         if (__cam0 > cam_max)
 217                 __cam0 = cam_max;
 218         ram -= __cam0;
 219         if (ram) {
 220                 __cam1 = 1UL << 2 * (__ilog2(ram) / 2);
 221                 if (__cam1 > cam_max)
 222                         __cam1 = cam_max;
 223                 ram -= __cam1;
 224         }
 225         if (ram) {
 226                 __cam2 = 1UL << 2 * (__ilog2(ram) / 2);
 227                 if (__cam2 > cam_max)
 228                         __cam2 = cam_max;
 229                 ram -= __cam2;
 230         }
 231
 232         printk(KERN_INFO "Memory CAM mapping: CAM0=%ldMb, CAM1=%ldMb,"
 233                         " CAM2=%ldMb residual: %ldMb\n",
 234                         __cam0 >> 20, __cam1 >> 20, __cam2 >> 20,
 235                         (total_lowmem - __cam0 - __cam1 - __cam2) >> 20);
 236         __max_low_memory = max_low_mem = __cam0 + __cam1 + __cam2;
 237 }