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/bootmem.h> 30 #include <linux/init.h> 31 #include <linux/delay.h> 32 #include <linux/blkdev.h> /* for initrd_* */ 33 #include <linux/pagemap.h> 34 #include <linux/memblock.h> 35 36 #include <asm/system.h> 37 #include <asm/segment.h> 38 #include <asm/pgalloc.h> 39 #include <asm/pgtable.h> 40 #include <asm/dma.h> 41 #include <asm/io.h> 42 #include <asm/tlb.h> 43 #include <asm/mmu_context.h> 44 #include <asm/kmap_types.h> 45 #include <asm/fixmap.h> 46 #include <asm/tlbflush.h> 47 48 int mem_init_done; 49 50 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 51 52 static void __init zone_sizes_init(void) 53 { 54 unsigned long zones_size[MAX_NR_ZONES]; 55 56 /* Clear the zone sizes */ 57 memset(zones_size, 0, sizeof(zones_size)); 58 59 /* 60 * We use only ZONE_NORMAL 61 */ 62 zones_size[ZONE_NORMAL] = max_low_pfn; 63 64 free_area_init(zones_size); 65 } 66 67 extern const char _s_kernel_ro[], _e_kernel_ro[]; 68 69 /* 70 * Map all physical memory into kernel's address space. 71 * 72 * This is explicitly coded for two-level page tables, so if you need 73 * something else then this needs to change. 74 */ 75 static void __init map_ram(void) 76 { 77 unsigned long v, p, e; 78 pgprot_t prot; 79 pgd_t *pge; 80 pud_t *pue; 81 pmd_t *pme; 82 pte_t *pte; 83 /* These mark extents of read-only kernel pages... 84 * ...from vmlinux.lds.S 85 */ 86 struct memblock_region *region; 87 88 v = PAGE_OFFSET; 89 90 for_each_memblock(memory, region) { 91 p = (u32) region->base & PAGE_MASK; 92 e = p + (u32) region->size; 93 94 v = (u32) __va(p); 95 pge = pgd_offset_k(v); 96 97 while (p < e) { 98 int j; 99 pue = pud_offset(pge, v); 100 pme = pmd_offset(pue, v); 101 102 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) { 103 panic("%s: OR1K kernel hardcoded for " 104 "two-level page tables", 105 __func__); 106 } 107 108 /* Alloc one page for holding PTE's... */ 109 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 110 set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte))); 111 112 /* Fill the newly allocated page with PTE'S */ 113 for (j = 0; p < e && j < PTRS_PER_PGD; 114 v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) { 115 if (v >= (u32) _e_kernel_ro || 116 v < (u32) _s_kernel_ro) 117 prot = PAGE_KERNEL; 118 else 119 prot = PAGE_KERNEL_RO; 120 121 set_pte(pte, mk_pte_phys(p, prot)); 122 } 123 124 pge++; 125 } 126 127 printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__, 128 region->base, region->base + region->size); 129 } 130 } 131 132 void __init paging_init(void) 133 { 134 extern void tlb_init(void); 135 136 unsigned long end; 137 int i; 138 139 printk(KERN_INFO "Setting up paging and PTEs.\n"); 140 141 /* clear out the init_mm.pgd that will contain the kernel's mappings */ 142 143 for (i = 0; i < PTRS_PER_PGD; i++) 144 swapper_pg_dir[i] = __pgd(0); 145 146 /* make sure the current pgd table points to something sane 147 * (even if it is most probably not used until the next 148 * switch_mm) 149 */ 150 current_pgd = init_mm.pgd; 151 152 end = (unsigned long)__va(max_low_pfn * PAGE_SIZE); 153 154 map_ram(); 155 156 zone_sizes_init(); 157 158 /* self modifying code ;) */ 159 /* Since the old TLB miss handler has been running up until now, 160 * the kernel pages are still all RW, so we can still modify the 161 * text directly... after this change and a TLB flush, the kernel 162 * pages will become RO. 163 */ 164 { 165 extern unsigned long dtlb_miss_handler; 166 extern unsigned long itlb_miss_handler; 167 168 unsigned long *dtlb_vector = __va(0x900); 169 unsigned long *itlb_vector = __va(0xa00); 170 171 printk(KERN_INFO "dtlb_miss_handler %p\n", &dtlb_miss_handler); 172 *dtlb_vector = ((unsigned long)&dtlb_miss_handler - 173 (unsigned long)dtlb_vector) >> 2; 174 175 printk(KERN_INFO "itlb_miss_handler %p\n", &itlb_miss_handler); 176 *itlb_vector = ((unsigned long)&itlb_miss_handler - 177 (unsigned long)itlb_vector) >> 2; 178 } 179 180 /* Invalidate instruction caches after code modification */ 181 mtspr(SPR_ICBIR, 0x900); 182 mtspr(SPR_ICBIR, 0xa00); 183 184 /* New TLB miss handlers and kernel page tables are in now place. 185 * Make sure that page flags get updated for all pages in TLB by 186 * flushing the TLB and forcing all TLB entries to be recreated 187 * from their page table flags. 188 */ 189 flush_tlb_all(); 190 } 191 192 /* References to section boundaries */ 193 194 extern char _stext, _etext, _edata, __bss_start, _end; 195 extern char __init_begin, __init_end; 196 197 static int __init free_pages_init(void) 198 { 199 int reservedpages, pfn; 200 201 /* this will put all low memory onto the freelists */ 202 totalram_pages = free_all_bootmem(); 203 204 reservedpages = 0; 205 for (pfn = 0; pfn < max_low_pfn; pfn++) { 206 /* 207 * Only count reserved RAM pages 208 */ 209 if (PageReserved(mem_map + pfn)) 210 reservedpages++; 211 } 212 213 return reservedpages; 214 } 215 216 static void __init set_max_mapnr_init(void) 217 { 218 max_mapnr = num_physpages = max_low_pfn; 219 } 220 221 void __init mem_init(void) 222 { 223 int codesize, reservedpages, datasize, initsize; 224 225 if (!mem_map) 226 BUG(); 227 228 set_max_mapnr_init(); 229 230 high_memory = (void *)__va(max_low_pfn * PAGE_SIZE); 231 232 /* clear the zero-page */ 233 memset((void *)empty_zero_page, 0, PAGE_SIZE); 234 235 reservedpages = free_pages_init(); 236 237 codesize = (unsigned long)&_etext - (unsigned long)&_stext; 238 datasize = (unsigned long)&_edata - (unsigned long)&_etext; 239 initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin; 240 241 printk(KERN_INFO 242 "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n", 243 (unsigned long)nr_free_pages() << (PAGE_SHIFT - 10), 244 max_mapnr << (PAGE_SHIFT - 10), codesize >> 10, 245 reservedpages << (PAGE_SHIFT - 10), datasize >> 10, 246 initsize >> 10, (unsigned long)(0 << (PAGE_SHIFT - 10)) 247 ); 248 249 printk("mem_init_done ...........................................\n"); 250 mem_init_done = 1; 251 return; 252 } 253 254 #ifdef CONFIG_BLK_DEV_INITRD 255 void free_initrd_mem(unsigned long start, unsigned long end) 256 { 257 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n", 258 (end - start) >> 10); 259 260 for (; start < end; start += PAGE_SIZE) { 261 ClearPageReserved(virt_to_page(start)); 262 init_page_count(virt_to_page(start)); 263 free_page(start); 264 totalram_pages++; 265 } 266 } 267 #endif 268 269 void free_initmem(void) 270 { 271 unsigned long addr; 272 273 addr = (unsigned long)(&__init_begin); 274 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 275 ClearPageReserved(virt_to_page(addr)); 276 init_page_count(virt_to_page(addr)); 277 free_page(addr); 278 totalram_pages++; 279 } 280 printk(KERN_INFO "Freeing unused kernel memory: %luk freed\n", 281 ((unsigned long)&__init_end - 282 (unsigned long)&__init_begin) >> 10); 283 } 284