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#include <linux/memblock.h>
  44
  45#include <asm/pgalloc.h>
  46#include <asm/prom.h>
  47#include <asm/io.h>
  48#include <asm/mmu_context.h>
  49#include <asm/pgtable.h>
  50#include <asm/mmu.h>
  51#include <linux/uaccess.h>
  52#include <asm/smp.h>
  53#include <asm/machdep.h>
  54#include <asm/setup.h>
  55#include <asm/paca.h>
  56
  57#include "mmu_decl.h"
  58
  59unsigned int tlbcam_index;
  60
  61#define NUM_TLBCAMS     (64)
  62struct tlbcam TLBCAM[NUM_TLBCAMS];
  63
  64struct tlbcamrange {
  65        unsigned long start;
  66        unsigned long limit;
  67        phys_addr_t phys;
  68} tlbcam_addrs[NUM_TLBCAMS];
  69
  70unsigned long tlbcam_sz(int idx)
  71{
  72        return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
  73}
  74
  75#ifdef CONFIG_FSL_BOOKE
  76/*
  77 * Return PA for this VA if it is mapped by a CAM, or 0
  78 */
  79phys_addr_t v_block_mapped(unsigned long va)
  80{
  81        int b;
  82        for (b = 0; b < tlbcam_index; ++b)
  83                if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
  84                        return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
  85        return 0;
  86}
  87
  88/*
  89 * Return VA for a given PA or 0 if not mapped
  90 */
  91unsigned long p_block_mapped(phys_addr_t pa)
  92{
  93        int b;
  94        for (b = 0; b < tlbcam_index; ++b)
  95                if (pa >= tlbcam_addrs[b].phys
  96                        && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
  97                              +tlbcam_addrs[b].phys)
  98                        return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
  99        return 0;
 100}
 101#endif
 102
 103/*
 104 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
 105 * in particular size must be a power of 4 between 4k and the max supported by
 106 * an implementation; max may further be limited by what can be represented in
 107 * an unsigned long (for example, 32-bit implementations cannot support a 4GB
 108 * size).
 109 */
 110static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 111                unsigned long size, unsigned long flags, unsigned int pid)
 112{
 113        unsigned int tsize;
 114
 115        tsize = __ilog2(size) - 10;
 116
 117#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
 118        if ((flags & _PAGE_NO_CACHE) == 0)
 119                flags |= _PAGE_COHERENT;
 120#endif
 121
 122        TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
 123        TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
 124        TLBCAM[index].MAS2 = virt & PAGE_MASK;
 125
 126        TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
 127        TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
 128        TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
 129        TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
 130        TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
 131
 132        TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
 133        TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 134        if (mmu_has_feature(MMU_FTR_BIG_PHYS))
 135                TLBCAM[index].MAS7 = (u64)phys >> 32;
 136
 137        /* Below is unlikely -- only for large user pages or similar */
 138        if (pte_user(__pte(flags))) {
 139           TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 140           TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 141        }
 142
 143        tlbcam_addrs[index].start = virt;
 144        tlbcam_addrs[index].limit = virt + size - 1;
 145        tlbcam_addrs[index].phys = phys;
 146}
 147
 148unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
 149                          phys_addr_t phys)
 150{
 151        unsigned int camsize = __ilog2(ram);
 152        unsigned int align = __ffs(virt | phys);
 153        unsigned long max_cam;
 154
 155        if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
 156                /* Convert (4^max) kB to (2^max) bytes */
 157                max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
 158                camsize &= ~1U;
 159                align &= ~1U;
 160        } else {
 161                /* Convert (2^max) kB to (2^max) bytes */
 162                max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
 163        }
 164
 165        if (camsize > align)
 166                camsize = align;
 167        if (camsize > max_cam)
 168                camsize = max_cam;
 169
 170        return 1UL << camsize;
 171}
 172
 173static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
 174                                        unsigned long ram, int max_cam_idx,
 175                                        bool dryrun)
 176{
 177        int i;
 178        unsigned long amount_mapped = 0;
 179
 180        /* Calculate CAM values */
 181        for (i = 0; ram && i < max_cam_idx; i++) {
 182                unsigned long cam_sz;
 183
 184                cam_sz = calc_cam_sz(ram, virt, phys);
 185                if (!dryrun)
 186                        settlbcam(i, virt, phys, cam_sz,
 187                                  pgprot_val(PAGE_KERNEL_X), 0);
 188
 189                ram -= cam_sz;
 190                amount_mapped += cam_sz;
 191                virt += cam_sz;
 192                phys += cam_sz;
 193        }
 194
 195        if (dryrun)
 196                return amount_mapped;
 197
 198        loadcam_multi(0, i, max_cam_idx);
 199        tlbcam_index = i;
 200
 201#ifdef CONFIG_PPC64
 202        get_paca()->tcd.esel_next = i;
 203        get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
 204        get_paca()->tcd.esel_first = i;
 205#endif
 206
 207        return amount_mapped;
 208}
 209
 210unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun)
 211{
 212        unsigned long virt = PAGE_OFFSET;
 213        phys_addr_t phys = memstart_addr;
 214
 215        return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun);
 216}
 217
 218#ifdef CONFIG_PPC32
 219
 220#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
 221#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
 222#endif
 223
 224unsigned long __init mmu_mapin_ram(unsigned long top)
 225{
 226        return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
 227}
 228
 229/*
 230 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 231 */
 232void __init MMU_init_hw(void)
 233{
 234        flush_instruction_cache();
 235}
 236
 237void __init adjust_total_lowmem(void)
 238{
 239        unsigned long ram;
 240        int i;
 241
 242        /* adjust lowmem size to __max_low_memory */
 243        ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 244
 245        i = switch_to_as1();
 246        __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false);
 247        restore_to_as0(i, 0, 0, 1);
 248
 249        pr_info("Memory CAM mapping: ");
 250        for (i = 0; i < tlbcam_index - 1; i++)
 251                pr_cont("%lu/", tlbcam_sz(i) >> 20);
 252        pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
 253                (unsigned int)((total_lowmem - __max_low_memory) >> 20));
 254
 255        memblock_set_current_limit(memstart_addr + __max_low_memory);
 256}
 257
 258void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 259                                phys_addr_t first_memblock_size)
 260{
 261        phys_addr_t limit = first_memblock_base + first_memblock_size;
 262
 263        /* 64M mapped initially according to head_fsl_booke.S */
 264        memblock_set_current_limit(min_t(u64, limit, 0x04000000));
 265}
 266
 267#ifdef CONFIG_RELOCATABLE
 268int __initdata is_second_reloc;
 269notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 270{
 271        unsigned long base = KERNELBASE;
 272
 273        kernstart_addr = start;
 274        if (is_second_reloc) {
 275                virt_phys_offset = PAGE_OFFSET - memstart_addr;
 276                return;
 277        }
 278
 279        /*
 280         * Relocatable kernel support based on processing of dynamic
 281         * relocation entries. Before we get the real memstart_addr,
 282         * We will compute the virt_phys_offset like this:
 283         * virt_phys_offset = stext.run - kernstart_addr
 284         *
 285         * stext.run = (KERNELBASE & ~0x3ffffff) +
 286         *                              (kernstart_addr & 0x3ffffff)
 287         * When we relocate, we have :
 288         *
 289         *      (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
 290         *
 291         * hence:
 292         *  virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
 293         *                              (kernstart_addr & ~0x3ffffff)
 294         *
 295         */
 296        start &= ~0x3ffffff;
 297        base &= ~0x3ffffff;
 298        virt_phys_offset = base - start;
 299        early_get_first_memblock_info(__va(dt_ptr), NULL);
 300        /*
 301         * We now get the memstart_addr, then we should check if this
 302         * address is the same as what the PAGE_OFFSET map to now. If
 303         * not we have to change the map of PAGE_OFFSET to memstart_addr
 304         * and do a second relocation.
 305         */
 306        if (start != memstart_addr) {
 307                int n;
 308                long offset = start - memstart_addr;
 309
 310                is_second_reloc = 1;
 311                n = switch_to_as1();
 312                /* map a 64M area for the second relocation */
 313                if (memstart_addr > start)
 314                        map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM,
 315                                        false);
 316                else
 317                        map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
 318                                        0x4000000, CONFIG_LOWMEM_CAM_NUM,
 319                                        false);
 320                restore_to_as0(n, offset, __va(dt_ptr), 1);
 321                /* We should never reach here */
 322                panic("Relocation error");
 323        }
 324}
 325#endif
 326#endif
 327