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