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 2004,2010 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
  59 unsigned int tlbcam_index;
  60
  61 #define NUM_TLBCAMS     (64)
  62 struct tlbcam TLBCAM[NUM_TLBCAMS];
  63
  64 struct tlbcamrange {
  65         unsigned long start;
  66         unsigned long limit;
  67         phys_addr_t phys;
  68 } tlbcam_addrs[NUM_TLBCAMS];
  69
  70 unsigned 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  */
  79 phys_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  */
  91 unsigned 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  */
 110 static 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
 148 unsigned 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
 173 static 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
 210 unsigned 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
 224 unsigned 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  */
 232 void __init MMU_init_hw(void)
 233 {
 234         flush_instruction_cache();
 235 }
 236
 237 void __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
 258 void 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
 268 int __initdata is_second_reloc;
 269 notrace 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