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
  56 #include "mmu_decl.h"
  57
  58 unsigned int tlbcam_index;
  59
  60 #define NUM_TLBCAMS     (64)
  61 struct tlbcam TLBCAM[NUM_TLBCAMS];
  62
  63 struct tlbcamrange {
  64         unsigned long start;
  65         unsigned long limit;
  66         phys_addr_t phys;
  67 } tlbcam_addrs[NUM_TLBCAMS];
  68
  69 extern unsigned int tlbcam_index;
  70
  71 unsigned long tlbcam_sz(int idx)
  72 {
  73         return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
  74 }
  75
  76 /*
  77  * Return PA for this VA if it is mapped by a CAM, or 0
  78  */
  79 phys_addr_t v_mapped_by_tlbcam(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_mapped_by_tlbcam(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
 102 /*
 103  * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
 104  * in particular size must be a power of 4 between 4k and 256M (or 1G, for cpus
 105  * that support extended page sizes).  Note that while some cpus support a
 106  * page size of 4G, we don't allow its use here.
 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, lz;
 112
 113         asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (size));
 114         tsize = 21 - lz;
 115
 116 #ifdef CONFIG_SMP
 117         if ((flags & _PAGE_NO_CACHE) == 0)
 118                 flags |= _PAGE_COHERENT;
 119 #endif
 120
 121         TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
 122         TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
 123         TLBCAM[index].MAS2 = virt & PAGE_MASK;
 124
 125         TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
 126         TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
 127         TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
 128         TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
 129         TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
 130
 131         TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
 132         TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 133         if (mmu_has_feature(MMU_FTR_BIG_PHYS))
 134                 TLBCAM[index].MAS7 = (u64)phys >> 32;
 135
 136         /* Below is unlikely -- only for large user pages or similar */
 137         if (pte_user(flags)) {
 138            TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 139            TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 140         }
 141
 142         tlbcam_addrs[index].start = virt;
 143         tlbcam_addrs[index].limit = virt + size - 1;
 144         tlbcam_addrs[index].phys = phys;
 145
 146         loadcam_entry(index);
 147 }
 148
 149 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
 150 {
 151         int i;
 152         unsigned long virt = PAGE_OFFSET;
 153         phys_addr_t phys = memstart_addr;
 154         unsigned long amount_mapped = 0;
 155         unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf;
 156
 157         /* Convert (4^max) kB to (2^max) bytes */
 158         max_cam = max_cam * 2 + 10;
 159
 160         /* Calculate CAM values */
 161         for (i = 0; ram && i < max_cam_idx; i++) {
 162                 unsigned int camsize = __ilog2(ram) & ~1U;
 163                 unsigned int align = __ffs(virt | phys) & ~1U;
 164                 unsigned long cam_sz;
 165
 166                 if (camsize > align)
 167                         camsize = align;
 168                 if (camsize > max_cam)
 169                         camsize = max_cam;
 170
 171                 cam_sz = 1UL << camsize;
 172                 settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);
 173
 174                 ram -= cam_sz;
 175                 amount_mapped += cam_sz;
 176                 virt += cam_sz;
 177                 phys += cam_sz;
 178         }
 179         tlbcam_index = i;
 180
 181         return amount_mapped;
 182 }
 183
 184 #ifdef CONFIG_PPC32
 185
 186 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
 187 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
 188 #endif
 189
 190 unsigned long __init mmu_mapin_ram(unsigned long top)
 191 {
 192         return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
 193 }
 194
 195 /*
 196  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 197  */
 198 void __init MMU_init_hw(void)
 199 {
 200         flush_instruction_cache();
 201 }
 202
 203 void __init adjust_total_lowmem(void)
 204 {
 205         unsigned long ram;
 206         int i;
 207
 208         /* adjust lowmem size to __max_low_memory */
 209         ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 210
 211         __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
 212
 213         pr_info("Memory CAM mapping: ");
 214         for (i = 0; i < tlbcam_index - 1; i++)
 215                 pr_cont("%lu/", tlbcam_sz(i) >> 20);
 216         pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
 217                 (unsigned int)((total_lowmem - __max_low_memory) >> 20));
 218
 219         memblock_set_current_limit(memstart_addr + __max_low_memory);
 220 }
 221
 222 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 223                                 phys_addr_t first_memblock_size)
 224 {
 225         phys_addr_t limit = first_memblock_base + first_memblock_size;
 226
 227         /* 64M mapped initially according to head_fsl_booke.S */
 228         memblock_set_current_limit(min_t(u64, limit, 0x04000000));
 229 }
 230 #endif