1 /* 2 * OpenRISC idle.c 3 * 4 * Linux architectural port borrowing liberally from similar works of 5 * others. All original copyrights apply as per the original source 6 * declaration. 7 * 8 * Modifications for the OpenRISC architecture: 9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> 10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 */ 17 18 #include <linux/signal.h> 19 #include <linux/sched.h> 20 #include <linux/kernel.h> 21 #include <linux/errno.h> 22 #include <linux/string.h> 23 #include <linux/types.h> 24 #include <linux/ptrace.h> 25 #include <linux/mman.h> 26 #include <linux/mm.h> 27 #include <linux/swap.h> 28 #include <linux/smp.h> 29 #include <linux/memblock.h> 30 #include <linux/init.h> 31 #include <linux/delay.h> 32 #include <linux/blkdev.h> /* for initrd_* */ 33 #include <linux/pagemap.h> 34 35 #include <asm/pgalloc.h> 36 #include <asm/pgtable.h> 37 #include <asm/dma.h> 38 #include <asm/io.h> 39 #include <asm/tlb.h> 40 #include <asm/mmu_context.h> 41 #include <asm/kmap_types.h> 42 #include <asm/fixmap.h> 43 #include <asm/tlbflush.h> 44 #include <asm/sections.h> 45 46 int mem_init_done; 47 48 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 49 50 static void __init zone_sizes_init(void) 51 { 52 unsigned long zones_size[MAX_NR_ZONES]; 53 54 /* Clear the zone sizes */ 55 memset(zones_size, 0, sizeof(zones_size)); 56 57 /* 58 * We use only ZONE_NORMAL 59 */ 60 zones_size[ZONE_NORMAL] = max_low_pfn; 61 62 free_area_init(zones_size); 63 } 64 65 extern const char _s_kernel_ro[], _e_kernel_ro[]; 66 67 /* 68 * Map all physical memory into kernel's address space. 69 * 70 * This is explicitly coded for two-level page tables, so if you need 71 * something else then this needs to change. 72 */ 73 static void __init map_ram(void) 74 { 75 unsigned long v, p, e; 76 pgprot_t prot; 77 pgd_t *pge; 78 pud_t *pue; 79 pmd_t *pme; 80 pte_t *pte; 81 /* These mark extents of read-only kernel pages... 82 * ...from vmlinux.lds.S 83 */ 84 struct memblock_region *region; 85 86 v = PAGE_OFFSET; 87 88 for_each_memblock(memory, region) { 89 p = (u32) region->base & PAGE_MASK; 90 e = p + (u32) region->size; 91 92 v = (u32) __va(p); 93 pge = pgd_offset_k(v); 94 95 while (p < e) { 96 int j; 97 pue = pud_offset(pge, v); 98 pme = pmd_offset(pue, v); 99 100 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) { 101 panic("%s: OR1K kernel hardcoded for " 102 "two-level page tables", 103 __func__); 104 } 105 106 /* Alloc one page for holding PTE's... */ 107 pte = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE); 108 if (!pte) 109 panic("%s: Failed to allocate page for PTEs\n", 110 __func__); 111 set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte))); 112 113 /* Fill the newly allocated page with PTE'S */ 114 for (j = 0; p < e && j < PTRS_PER_PTE; 115 v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) { 116 if (v >= (u32) _e_kernel_ro || 117 v < (u32) _s_kernel_ro) 118 prot = PAGE_KERNEL; 119 else 120 prot = PAGE_KERNEL_RO; 121 122 set_pte(pte, mk_pte_phys(p, prot)); 123 } 124 125 pge++; 126 } 127 128 printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__, 129 region->base, region->base + region->size); 130 } 131 } 132 133 void __init paging_init(void) 134 { 135 extern void tlb_init(void); 136 137 unsigned long end; 138 int i; 139 140 printk(KERN_INFO "Setting up paging and PTEs.\n"); 141 142 /* clear out the init_mm.pgd that will contain the kernel's mappings */ 143 144 for (i = 0; i < PTRS_PER_PGD; i++) 145 swapper_pg_dir[i] = __pgd(0); 146 147 /* make sure the current pgd table points to something sane 148 * (even if it is most probably not used until the next 149 * switch_mm) 150 */ 151 current_pgd[smp_processor_id()] = init_mm.pgd; 152 153 end = (unsigned long)__va(max_low_pfn * PAGE_SIZE); 154 155 map_ram(); 156 157 zone_sizes_init(); 158 159 /* self modifying code ;) */ 160 /* Since the old TLB miss handler has been running up until now, 161 * the kernel pages are still all RW, so we can still modify the 162 * text directly... after this change and a TLB flush, the kernel 163 * pages will become RO. 164 */ 165 { 166 extern unsigned long dtlb_miss_handler; 167 extern unsigned long itlb_miss_handler; 168 169 unsigned long *dtlb_vector = __va(0x900); 170 unsigned long *itlb_vector = __va(0xa00); 171 172 printk(KERN_INFO "itlb_miss_handler %p\n", &itlb_miss_handler); 173 *itlb_vector = ((unsigned long)&itlb_miss_handler - 174 (unsigned long)itlb_vector) >> 2; 175 176 /* Soft ordering constraint to ensure that dtlb_vector is 177 * the last thing updated 178 */ 179 barrier(); 180 181 printk(KERN_INFO "dtlb_miss_handler %p\n", &dtlb_miss_handler); 182 *dtlb_vector = ((unsigned long)&dtlb_miss_handler - 183 (unsigned long)dtlb_vector) >> 2; 184 185 } 186 187 /* Soft ordering constraint to ensure that cache invalidation and 188 * TLB flush really happen _after_ code has been modified. 189 */ 190 barrier(); 191 192 /* Invalidate instruction caches after code modification */ 193 mtspr(SPR_ICBIR, 0x900); 194 mtspr(SPR_ICBIR, 0xa00); 195 196 /* New TLB miss handlers and kernel page tables are in now place. 197 * Make sure that page flags get updated for all pages in TLB by 198 * flushing the TLB and forcing all TLB entries to be recreated 199 * from their page table flags. 200 */ 201 flush_tlb_all(); 202 } 203 204 /* References to section boundaries */ 205 206 void __init mem_init(void) 207 { 208 BUG_ON(!mem_map); 209 210 max_mapnr = max_low_pfn; 211 high_memory = (void *)__va(max_low_pfn * PAGE_SIZE); 212 213 /* clear the zero-page */ 214 memset((void *)empty_zero_page, 0, PAGE_SIZE); 215 216 /* this will put all low memory onto the freelists */ 217 memblock_free_all(); 218 219 mem_init_print_info(NULL); 220 221 printk("mem_init_done ...........................................\n"); 222 mem_init_done = 1; 223 return; 224 } 225