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 <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
  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 extern unsigned int tlbcam_index;
  71
  72 unsigned 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  */
  80 phys_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  */
  92 unsigned 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  */
 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 #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
 150 unsigned 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
 175 static 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
 204 unsigned 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
 218 unsigned 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  */
 226 void __init MMU_init_hw(void)
 227 {
 228         flush_instruction_cache();
 229 }
 230
 231 void __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
 252 void 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
 262 int __initdata is_second_reloc;
 263 notrace 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