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/machdep.h>
  53 #include <asm/setup.h>
  54
  55 #include "mmu_decl.h"
  56
  57 extern void loadcam_entry(unsigned int index);
  58 unsigned int tlbcam_index;
  59 static unsigned long cam[CONFIG_LOWMEM_CAM_NUM];
  60
  61 #define NUM_TLBCAMS     (16)
  62
  63 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
  64 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
  65 #endif
  66
  67 struct tlbcam TLBCAM[NUM_TLBCAMS];
  68
  69 struct tlbcamrange {
  70         unsigned long start;
  71         unsigned long limit;
  72         phys_addr_t phys;
  73 } tlbcam_addrs[NUM_TLBCAMS];
  74
  75 extern unsigned int tlbcam_index;
  76
  77 /*
  78  * Return PA for this VA if it is mapped by a CAM, or 0
  79  */
  80 phys_addr_t v_mapped_by_tlbcam(unsigned long va)
  81 {
  82         int b;
  83         for (b = 0; b < tlbcam_index; ++b)
  84                 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
  85                         return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
  86         return 0;
  87 }
  88
  89 /*
  90  * Return VA for a given PA or 0 if not mapped
  91  */
  92 unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
  93 {
  94         int b;
  95         for (b = 0; b < tlbcam_index; ++b)
  96                 if (pa >= tlbcam_addrs[b].phys
  97                     && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
  98                               +tlbcam_addrs[b].phys)
  99                         return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
 100         return 0;
 101 }
 102
 103 /*
 104  * Set up one of the I/D BAT (block address translation) register pairs.
 105  * The parameters are not checked; in particular size must be a power
 106  * of 4 between 4k and 256M.
 107  */
 108 void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 109                 unsigned int size, int flags, unsigned int pid)
 110 {
 111         unsigned int tsize, lz;
 112
 113         asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));
 114         tsize = 21 - lz;
 115
 116 #ifdef CONFIG_SMP
 117         if ((flags & _PAGE_NO_CACHE) == 0)
 118                 flags |= _PAGE_COHERENT;
 119 #endif
 120
 121         TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
 122         TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
 123         TLBCAM[index].MAS2 = virt & PAGE_MASK;
 124
 125         TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
 126         TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
 127         TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
 128         TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
 129         TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
 130
 131         TLBCAM[index].MAS3 = (phys & PAGE_MASK) | MAS3_SX | MAS3_SR;
 132         TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 133
 134 #ifndef CONFIG_KGDB /* want user access for breakpoints */
 135         if (flags & _PAGE_USER) {
 136            TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 137            TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 138         }
 139 #else
 140         TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 141         TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 142 #endif
 143
 144         tlbcam_addrs[index].start = virt;
 145         tlbcam_addrs[index].limit = virt + size - 1;
 146         tlbcam_addrs[index].phys = phys;
 147
 148         loadcam_entry(index);
 149 }
 150
 151 void invalidate_tlbcam_entry(int index)
 152 {
 153         TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index);
 154         TLBCAM[index].MAS1 = ~MAS1_VALID;
 155
 156         loadcam_entry(index);
 157 }
 158
 159 unsigned long __init mmu_mapin_ram(void)
 160 {
 161         unsigned long virt = PAGE_OFFSET;
 162         phys_addr_t phys = memstart_addr;
 163
 164         while (cam[tlbcam_index] && tlbcam_index < ARRAY_SIZE(cam)) {
 165                 settlbcam(tlbcam_index, virt, phys, cam[tlbcam_index], PAGE_KERNEL_X, 0);
 166                 virt += cam[tlbcam_index];
 167                 phys += cam[tlbcam_index];
 168                 tlbcam_index++;
 169         }
 170
 171         return virt - PAGE_OFFSET;
 172 }
 173
 174 /*
 175  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 176  */
 177 void __init MMU_init_hw(void)
 178 {
 179         flush_instruction_cache();
 180 }
 181
 182 void __init
 183 adjust_total_lowmem(void)
 184 {
 185         phys_addr_t ram;
 186         unsigned int max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xff;
 187         char buf[ARRAY_SIZE(cam) * 5 + 1], *p = buf;
 188         int i;
 189         unsigned long virt = PAGE_OFFSET & 0xffffffffUL;
 190         unsigned long phys = memstart_addr & 0xffffffffUL;
 191
 192         /* Convert (4^max) kB to (2^max) bytes */
 193         max_cam = max_cam * 2 + 10;
 194
 195         /* adjust lowmem size to __max_low_memory */
 196         ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 197
 198         /* Calculate CAM values */
 199         __max_low_memory = 0;
 200         for (i = 0; ram && i < ARRAY_SIZE(cam); i++) {
 201                 unsigned int camsize = __ilog2(ram) & ~1U;
 202                 unsigned int align = __ffs(virt | phys) & ~1U;
 203
 204                 if (camsize > align)
 205                         camsize = align;
 206                 if (camsize > max_cam)
 207                         camsize = max_cam;
 208
 209                 cam[i] = 1UL << camsize;
 210                 ram -= cam[i];
 211                 __max_low_memory += cam[i];
 212                 virt += cam[i];
 213                 phys += cam[i];
 214
 215                 p += sprintf(p, "%lu/", cam[i] >> 20);
 216         }
 217         for (; i < ARRAY_SIZE(cam); i++)
 218                 p += sprintf(p, "0/");
 219         p[-1] = '\0';
 220
 221         pr_info("Memory CAM mapping: %s Mb, residual: %dMb\n", buf,
 222                 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
 223         __initial_memory_limit_addr = memstart_addr + __max_low_memory;
 224 }