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 unsigned int tlbcam_index;
  58
  59 #define NUM_TLBCAMS     (64)
  60
  61 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
  62 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
  63 #endif
  64
  65 struct tlbcam {
  66         u32     MAS0;
  67         u32     MAS1;
  68         unsigned long   MAS2;
  69         u32     MAS3;
  70         u32     MAS7;
  71 } TLBCAM[NUM_TLBCAMS];
  72
  73 struct tlbcamrange {
  74         unsigned long start;
  75         unsigned long limit;
  76         phys_addr_t phys;
  77 } tlbcam_addrs[NUM_TLBCAMS];
  78
  79 extern unsigned int tlbcam_index;
  80
  81 unsigned long tlbcam_sz(int idx)
  82 {
  83         return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
  84 }
  85
  86 /*
  87  * Return PA for this VA if it is mapped by a CAM, or 0
  88  */
  89 phys_addr_t v_mapped_by_tlbcam(unsigned long va)
  90 {
  91         int b;
  92         for (b = 0; b < tlbcam_index; ++b)
  93                 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
  94                         return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
  95         return 0;
  96 }
  97
  98 /*
  99  * Return VA for a given PA or 0 if not mapped
 100  */
 101 unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
 102 {
 103         int b;
 104         for (b = 0; b < tlbcam_index; ++b)
 105                 if (pa >= tlbcam_addrs[b].phys
 106                         && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
 107                               +tlbcam_addrs[b].phys)
 108                         return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
 109         return 0;
 110 }
 111
 112 void loadcam_entry(int idx)
 113 {
 114         mtspr(SPRN_MAS0, TLBCAM[idx].MAS0);
 115         mtspr(SPRN_MAS1, TLBCAM[idx].MAS1);
 116         mtspr(SPRN_MAS2, TLBCAM[idx].MAS2);
 117         mtspr(SPRN_MAS3, TLBCAM[idx].MAS3);
 118
 119         if (cur_cpu_spec->cpu_features & MMU_FTR_BIG_PHYS)
 120                 mtspr(SPRN_MAS7, TLBCAM[idx].MAS7);
 121
 122         asm volatile("isync;tlbwe;isync" : : : "memory");
 123 }
 124
 125 /*
 126  * Set up one of the I/D BAT (block address translation) register pairs.
 127  * The parameters are not checked; in particular size must be a power
 128  * of 4 between 4k and 256M.
 129  */
 130 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 131                 unsigned long size, unsigned long flags, unsigned int pid)
 132 {
 133         unsigned int tsize, lz;
 134
 135         asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (size));
 136         tsize = 21 - lz;
 137
 138 #ifdef CONFIG_SMP
 139         if ((flags & _PAGE_NO_CACHE) == 0)
 140                 flags |= _PAGE_COHERENT;
 141 #endif
 142
 143         TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
 144         TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
 145         TLBCAM[index].MAS2 = virt & PAGE_MASK;
 146
 147         TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
 148         TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
 149         TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
 150         TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
 151         TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
 152
 153         TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
 154         TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 155         if (cur_cpu_spec->cpu_features & MMU_FTR_BIG_PHYS)
 156                 TLBCAM[index].MAS7 = (u64)phys >> 32;
 157
 158 #ifndef CONFIG_KGDB /* want user access for breakpoints */
 159         if (flags & _PAGE_USER) {
 160            TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 161            TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 162         }
 163 #else
 164         TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 165         TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 166 #endif
 167
 168         tlbcam_addrs[index].start = virt;
 169         tlbcam_addrs[index].limit = virt + size - 1;
 170         tlbcam_addrs[index].phys = phys;
 171
 172         loadcam_entry(index);
 173 }
 174
 175 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
 176 {
 177         int i;
 178         unsigned long virt = PAGE_OFFSET;
 179         phys_addr_t phys = memstart_addr;
 180         unsigned long amount_mapped = 0;
 181         unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf;
 182
 183         /* Convert (4^max) kB to (2^max) bytes */
 184         max_cam = max_cam * 2 + 10;
 185
 186         /* Calculate CAM values */
 187         for (i = 0; ram && i < max_cam_idx; i++) {
 188                 unsigned int camsize = __ilog2(ram) & ~1U;
 189                 unsigned int align = __ffs(virt | phys) & ~1U;
 190                 unsigned long cam_sz;
 191
 192                 if (camsize > align)
 193                         camsize = align;
 194                 if (camsize > max_cam)
 195                         camsize = max_cam;
 196
 197                 cam_sz = 1UL << camsize;
 198                 settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
 199
 200                 ram -= cam_sz;
 201                 amount_mapped += cam_sz;
 202                 virt += cam_sz;
 203                 phys += cam_sz;
 204         }
 205         tlbcam_index = i;
 206
 207         return amount_mapped;
 208 }
 209
 210 unsigned long __init mmu_mapin_ram(void)
 211 {
 212         return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
 213 }
 214
 215 /*
 216  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 217  */
 218 void __init MMU_init_hw(void)
 219 {
 220         flush_instruction_cache();
 221 }
 222
 223 void __init adjust_total_lowmem(void)
 224 {
 225         unsigned long ram;
 226         int i;
 227
 228         /* adjust lowmem size to __max_low_memory */
 229         ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 230
 231         __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
 232
 233         pr_info("Memory CAM mapping: ");
 234         for (i = 0; i < tlbcam_index - 1; i++)
 235                 pr_cont("%lu/", tlbcam_sz(i) >> 20);
 236         pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
 237                 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
 238
 239         __initial_memory_limit_addr = memstart_addr + __max_low_memory;
 240 }