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 57unsigned 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) 65struct tlbcam TLBCAM[NUM_TLBCAMS]; 66 67struct tlbcamrange { 68 unsigned long start; 69 unsigned long limit; 70 phys_addr_t phys; 71} tlbcam_addrs[NUM_TLBCAMS]; 72 73extern unsigned int tlbcam_index; 74 75unsigned 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 */ 83phys_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 */ 95unsigned 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 a variable-size TLB entry (tlbcam). The parameters are not checked; 108 * in particular size must be a power of 4 between 4k and 256M (or 1G, for cpus 109 * that support extended page sizes). Note that while some cpus support a 110 * page size of 4G, we don't allow its use here. 111 */ 112static void settlbcam(int index, unsigned long virt, phys_addr_t phys, 113 unsigned long size, unsigned long flags, unsigned int pid) 114{ 115 unsigned int tsize, lz; 116 117 asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (size)); 118 tsize = 21 - lz; 119 120#ifdef CONFIG_SMP 121 if ((flags & _PAGE_NO_CACHE) == 0) 122 flags |= _PAGE_COHERENT; 123#endif 124 125 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1); 126 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid); 127 TLBCAM[index].MAS2 = virt & PAGE_MASK; 128 129 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0; 130 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0; 131 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0; 132 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0; 133 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0; 134 135 TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR; 136 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0); 137 if (mmu_has_feature(MMU_FTR_BIG_PHYS)) 138 TLBCAM[index].MAS7 = (u64)phys >> 32; 139 140 if (flags & _PAGE_USER) { 141 TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR; 142 TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0); 143 } 144 145 tlbcam_addrs[index].start = virt; 146 tlbcam_addrs[index].limit = virt + size - 1; 147 tlbcam_addrs[index].phys = phys; 148 149 loadcam_entry(index); 150} 151 152unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx) 153{ 154 int i; 155 unsigned long virt = PAGE_OFFSET; 156 phys_addr_t phys = memstart_addr; 157 unsigned long amount_mapped = 0; 158 unsigned long max_cam = (mfspr(SPRN_TLB1CFG) >> 16) & 0xf; 159 160 /* Convert (4^max) kB to (2^max) bytes */ 161 max_cam = max_cam * 2 + 10; 162 163 /* Calculate CAM values */ 164 for (i = 0; ram && i < max_cam_idx; i++) { 165 unsigned int camsize = __ilog2(ram) & ~1U; 166 unsigned int align = __ffs(virt | phys) & ~1U; 167 unsigned long cam_sz; 168 169 if (camsize > align) 170 camsize = align; 171 if (camsize > max_cam) 172 camsize = max_cam; 173 174 cam_sz = 1UL << camsize; 175 settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0); 176 177 ram -= cam_sz; 178 amount_mapped += cam_sz; 179 virt += cam_sz; 180 phys += cam_sz; 181 } 182 tlbcam_index = i; 183 184 return amount_mapped; 185} 186 187unsigned long __init mmu_mapin_ram(unsigned long top) 188{ 189 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1; 190} 191 192/* 193 * MMU_init_hw does the chip-specific initialization of the MMU hardware. 194 */ 195void __init MMU_init_hw(void) 196{ 197 flush_instruction_cache(); 198} 199 200void __init adjust_total_lowmem(void) 201{ 202 unsigned long ram; 203 int i; 204 205 /* adjust lowmem size to __max_low_memory */ 206 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem); 207 208 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM); 209 210 pr_info("Memory CAM mapping: "); 211 for (i = 0; i < tlbcam_index - 1; i++) 212 pr_cont("%lu/", tlbcam_sz(i) >> 20); 213 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20, 214 (unsigned int)((total_lowmem - __max_low_memory) >> 20)); 215 216 __initial_memory_limit_addr = memstart_addr + __max_low_memory; 217} 218