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 <asm/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
  70extern unsigned int tlbcam_index;
  71
  72unsigned long tlbcam_sz(int idx)
  73{
  74        return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
  75}
  76
  77/*
  78 * Return PA for this VA if it is mapped by a CAM, or 0
  79 */
  80phys_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 */
  92unsigned 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 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#ifdef CONFIG_SMP
 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(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        loadcam_entry(index);
 148}
 149
 150unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
 151                          phys_addr_t phys)
 152{
 153        unsigned int camsize = __ilog2(ram);
 154        unsigned int align = __ffs(virt | phys);
 155        unsigned long max_cam;
 156
 157        if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
 158                /* Convert (4^max) kB to (2^max) bytes */
 159                max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
 160                camsize &= ~1U;
 161                align &= ~1U;
 162        } else {
 163                /* Convert (2^max) kB to (2^max) bytes */
 164                max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
 165        }
 166
 167        if (camsize > align)
 168                camsize = align;
 169        if (camsize > max_cam)
 170                camsize = max_cam;
 171
 172        return 1UL << camsize;
 173}
 174
 175static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
 176                                        unsigned long ram, int max_cam_idx)
 177{
 178        int i;
 179        unsigned long amount_mapped = 0;
 180
 181        /* Calculate CAM values */
 182        for (i = 0; ram && i < max_cam_idx; i++) {
 183                unsigned long cam_sz;
 184
 185                cam_sz = calc_cam_sz(ram, virt, phys);
 186                settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
 187
 188                ram -= cam_sz;
 189                amount_mapped += cam_sz;
 190                virt += cam_sz;
 191                phys += cam_sz;
 192        }
 193        tlbcam_index = i;
 194
 195#ifdef CONFIG_PPC64
 196        get_paca()->tcd.esel_next = i;
 197        get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
 198        get_paca()->tcd.esel_first = i;
 199#endif
 200
 201        return amount_mapped;
 202}
 203
 204unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
 205{
 206        unsigned long virt = PAGE_OFFSET;
 207        phys_addr_t phys = memstart_addr;
 208
 209        return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx);
 210}
 211
 212#ifdef CONFIG_PPC32
 213
 214#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
 215#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
 216#endif
 217
 218unsigned long __init mmu_mapin_ram(unsigned long top)
 219{
 220        return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
 221}
 222
 223/*
 224 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 225 */
 226void __init MMU_init_hw(void)
 227{
 228        flush_instruction_cache();
 229}
 230
 231void __init adjust_total_lowmem(void)
 232{
 233        unsigned long ram;
 234        int i;
 235
 236        /* adjust lowmem size to __max_low_memory */
 237        ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 238
 239        i = switch_to_as1();
 240        __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
 241        restore_to_as0(i, 0, 0, 1);
 242
 243        pr_info("Memory CAM mapping: ");
 244        for (i = 0; i < tlbcam_index - 1; i++)
 245                pr_cont("%lu/", tlbcam_sz(i) >> 20);
 246        pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
 247                (unsigned int)((total_lowmem - __max_low_memory) >> 20));
 248
 249        memblock_set_current_limit(memstart_addr + __max_low_memory);
 250}
 251
 252void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 253                                phys_addr_t first_memblock_size)
 254{
 255        phys_addr_t limit = first_memblock_base + first_memblock_size;
 256
 257        /* 64M mapped initially according to head_fsl_booke.S */
 258        memblock_set_current_limit(min_t(u64, limit, 0x04000000));
 259}
 260
 261#ifdef CONFIG_RELOCATABLE
 262int __initdata is_second_reloc;
 263notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 264{
 265        unsigned long base = KERNELBASE;
 266
 267        kernstart_addr = start;
 268        if (is_second_reloc) {
 269                virt_phys_offset = PAGE_OFFSET - memstart_addr;
 270                return;
 271        }
 272
 273        /*
 274         * Relocatable kernel support based on processing of dynamic
 275         * relocation entries. Before we get the real memstart_addr,
 276         * We will compute the virt_phys_offset like this:
 277         * virt_phys_offset = stext.run - kernstart_addr
 278         *
 279         * stext.run = (KERNELBASE & ~0x3ffffff) +
 280         *                              (kernstart_addr & 0x3ffffff)
 281         * When we relocate, we have :
 282         *
 283         *      (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
 284         *
 285         * hence:
 286         *  virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
 287         *                              (kernstart_addr & ~0x3ffffff)
 288         *
 289         */
 290        start &= ~0x3ffffff;
 291        base &= ~0x3ffffff;
 292        virt_phys_offset = base - start;
 293        early_get_first_memblock_info(__va(dt_ptr), NULL);
 294        /*
 295         * We now get the memstart_addr, then we should check if this
 296         * address is the same as what the PAGE_OFFSET map to now. If
 297         * not we have to change the map of PAGE_OFFSET to memstart_addr
 298         * and do a second relocation.
 299         */
 300        if (start != memstart_addr) {
 301                int n;
 302                long offset = start - memstart_addr;
 303
 304                is_second_reloc = 1;
 305                n = switch_to_as1();
 306                /* map a 64M area for the second relocation */
 307                if (memstart_addr > start)
 308                        map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM);
 309                else
 310                        map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
 311                                        0x4000000, CONFIG_LOWMEM_CAM_NUM);
 312                restore_to_as0(n, offset, __va(dt_ptr), 1);
 313                /* We should never reach here */
 314                panic("Relocation error");
 315        }
 316}
 317#endif
 318#endif
 319