LXR linux/arch/powerpc/mm/fsl_booke

   1/*
   2 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
   3 * E500 Book E processors.
   4 *
   5 * Copyright 2004,2010 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
  57unsigned int tlbcam_index;
  58
  59
  60#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
  61#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
  62#endif
  63
  64#define NUM_TLBCAMS     (64)
  65struct tlbcam TLBCAM[NUM_TLBCAMS];
  66
  67struct tlbcamrange {
  68        unsigned long start;
  69        unsigned long limit;
  70        phys_addr_t phys;
  71} tlbcam_addrs[NUM_TLBCAMS];
  72
  73extern unsigned int tlbcam_index;
  74
  75unsigned long tlbcam_sz(int idx)
  76{
  77        return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
  78}
  79
  80/*
  81 * Return PA for this VA if it is mapped by a CAM, or 0
  82 */
  83phys_addr_t v_mapped_by_tlbcam(unsigned long va)
  84{
  85        int b;
  86        for (b = 0; b < tlbcam_index; ++b)
  87                if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
  88                        return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
  89        return 0;
  90}
  91
  92/*
  93 * Return VA for a given PA or 0 if not mapped
  94 */
  95unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
  96{
  97        int b;
  98        for (b = 0; b < tlbcam_index; ++b)
  99                if (pa >= tlbcam_addrs[b].phys
 100                        && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
 101                              +tlbcam_addrs[b].phys)
 102                        return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
 103        return 0;
 104}
 105
 106/*
 107 * Set up one of the I/D BAT (block address translation) register pairs.
 108 * The parameters are not checked; in particular size must be a power
 109 * of 4 between 4k and 256M.
 110 */
 111static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 112                unsigned long size, unsigned long flags, unsigned int pid)
 113{
 114        unsigned int tsize, lz;
 115
 116        asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (size));
 117        tsize = 21 - lz;
 118
 119#ifdef CONFIG_SMP
 120        if ((flags & _PAGE_NO_CACHE) == 0)
 121                flags |= _PAGE_COHERENT;
 122#endif
 123
 124        TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
 125        TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
 126        TLBCAM[index].MAS2 = virt & PAGE_MASK;
 127
 128        TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
 129        TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
 130        TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
 131        TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
 132        TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
 133
 134        TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
 135        TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 136        if (mmu_has_feature(MMU_FTR_BIG_PHYS))
 137                TLBCAM[index].MAS7 = (u64)phys >> 32;
 138
 139        if (flags & _PAGE_USER) {
 140           TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 141           TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 142        }
 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
 151unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
 152{
 153        int i;
 154        unsigned long virt = PAGE_OFFSET;
 155        phys_addr_t phys = memstart_addr;
 156        unsigned long amount_mapped = 0;
 157        unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf;
 158
 159        /* Convert (4^max) kB to (2^max) bytes */
 160        max_cam = max_cam * 2 + 10;
 161
 162        /* Calculate CAM values */
 163        for (i = 0; ram && i < max_cam_idx; i++) {
 164                unsigned int camsize = __ilog2(ram) & ~1U;
 165                unsigned int align = __ffs(virt | phys) & ~1U;
 166                unsigned long cam_sz;
 167
 168                if (camsize > align)
 169                        camsize = align;
 170                if (camsize > max_cam)
 171                        camsize = max_cam;
 172
 173                cam_sz = 1UL << camsize;
 174                settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
 175
 176                ram -= cam_sz;
 177                amount_mapped += cam_sz;
 178                virt += cam_sz;
 179                phys += cam_sz;
 180        }
 181        tlbcam_index = i;
 182
 183        return amount_mapped;
 184}
 185
 186unsigned long __init mmu_mapin_ram(unsigned long top)
 187{
 188        return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
 189}
 190
 191/*
 192 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 193 */
 194void __init MMU_init_hw(void)
 195{
 196        flush_instruction_cache();
 197}
 198
 199void __init adjust_total_lowmem(void)
 200{
 201        unsigned long ram;
 202        int i;
 203
 204        /* adjust lowmem size to __max_low_memory */
 205        ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 206
 207        __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
 208
 209        pr_info("Memory CAM mapping: ");
 210        for (i = 0; i < tlbcam_index - 1; i++)
 211                pr_cont("%lu/", tlbcam_sz(i) >> 20);
 212        pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
 213                (unsigned int)((total_lowmem - __max_low_memory) >> 20));
 214
 215        __initial_memory_limit_addr = memstart_addr + __max_low_memory;
 216}
 217