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
  44 #include <asm/pgalloc.h>
  45 #include <asm/prom.h>
  46 #include <asm/io.h>
  47 #include <asm/mmu_context.h>
  48 #include <asm/pgtable.h>
  49 #include <asm/mmu.h>
  50 #include <asm/uaccess.h>
  51 #include <asm/smp.h>
  52 #include <asm/machdep.h>
  53 #include <asm/setup.h>
  54
  55 #include "mmu_decl.h"
  56
  57 unsigned int tlbcam_index;
  58
  59
  60 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
  61 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
  62 #endif
  63
  64 #define NUM_TLBCAMS     (64)
  65 struct tlbcam TLBCAM[NUM_TLBCAMS];
  66
  67 struct tlbcamrange {
  68         unsigned long start;
  69         unsigned long limit;
  70         phys_addr_t phys;
  71 } tlbcam_addrs[NUM_TLBCAMS];
  72
  73 extern unsigned int tlbcam_index;
  74
  75 unsigned long tlbcam_sz(int idx)
  76 {
  77         return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
  78 }
  79
  80 /*
  81  * Return PA for this VA if it is mapped by a CAM, or 0
  82  */
  83 phys_addr_t v_mapped_by_tlbcam(unsigned long va)
  84 {
  85         int b;
  86         for (b = 0; b < tlbcam_index; ++b)
  87                 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
  88                         return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
  89         return 0;
  90 }
  91
  92 /*
  93  * Return VA for a given PA or 0 if not mapped
  94  */
  95 unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
  96 {
  97         int b;
  98         for (b = 0; b < tlbcam_index; ++b)
  99                 if (pa >= tlbcam_addrs[b].phys
 100                         && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
 101                               +tlbcam_addrs[b].phys)
 102                         return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
 103         return 0;
 104 }
 105
 106 /*
 107  * Set up one of the I/D BAT (block address translation) register pairs.
 108  * The parameters are not checked; in particular size must be a power
 109  * of 4 between 4k and 256M.
 110  */
 111 static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 112                 unsigned long size, unsigned long flags, unsigned int pid)
 113 {
 114         unsigned int tsize, lz;
 115
 116         asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (size));
 117         tsize = 21 - lz;
 118
 119 #ifdef CONFIG_SMP
 120         if ((flags & _PAGE_NO_CACHE) == 0)
 121                 flags |= _PAGE_COHERENT;
 122 #endif
 123
 124         TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
 125         TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
 126         TLBCAM[index].MAS2 = virt & PAGE_MASK;
 127
 128         TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
 129         TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
 130         TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
 131         TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
 132         TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
 133
 134         TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
 135         TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 136         if (mmu_has_feature(MMU_FTR_BIG_PHYS))
 137                 TLBCAM[index].MAS7 = (u64)phys >> 32;
 138
 139         if (flags & _PAGE_USER) {
 140            TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 141            TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 142         }
 143
 144         tlbcam_addrs[index].start = virt;
 145         tlbcam_addrs[index].limit = virt + size - 1;
 146         tlbcam_addrs[index].phys = phys;
 147
 148         loadcam_entry(index);
 149 }
 150
 151 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
 152 {
 153         int i;
 154         unsigned long virt = PAGE_OFFSET;
 155         phys_addr_t phys = memstart_addr;
 156         unsigned long amount_mapped = 0;
 157         unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf;
 158
 159         /* Convert (4^max) kB to (2^max) bytes */
 160         max_cam = max_cam * 2 + 10;
 161
 162         /* Calculate CAM values */
 163         for (i = 0; ram && i < max_cam_idx; i++) {
 164                 unsigned int camsize = __ilog2(ram) & ~1U;
 165                 unsigned int align = __ffs(virt | phys) & ~1U;
 166                 unsigned long cam_sz;
 167
 168                 if (camsize > align)
 169                         camsize = align;
 170                 if (camsize > max_cam)
 171                         camsize = max_cam;
 172
 173                 cam_sz = 1UL << camsize;
 174                 settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
 175
 176                 ram -= cam_sz;
 177                 amount_mapped += cam_sz;
 178                 virt += cam_sz;
 179                 phys += cam_sz;
 180         }
 181         tlbcam_index = i;
 182
 183         return amount_mapped;
 184 }
 185
 186 unsigned long __init mmu_mapin_ram(unsigned long top)
 187 {
 188         return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
 189 }
 190
 191 /*
 192  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 193  */
 194 void __init MMU_init_hw(void)
 195 {
 196         flush_instruction_cache();
 197 }
 198
 199 void __init adjust_total_lowmem(void)
 200 {
 201         unsigned long ram;
 202         int i;
 203
 204         /* adjust lowmem size to __max_low_memory */
 205         ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 206
 207         __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
 208
 209         pr_info("Memory CAM mapping: ");
 210         for (i = 0; i < tlbcam_index - 1; i++)
 211                 pr_cont("%lu/", tlbcam_sz(i) >> 20);
 212         pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
 213                 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
 214
 215         __initial_memory_limit_addr = memstart_addr + __max_low_memory;
 216 }