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