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/segment.h> 37 #include <asm/pgalloc.h> 38 #include <asm/pgtable.h> 39 #include <asm/dma.h> 40 #include <asm/io.h> 41 #include <asm/tlb.h> 42 #include <asm/mmu_context.h> 43 #include <asm/kmap_types.h> 44 #include <asm/fixmap.h> 45 #include <asm/tlbflush.h> 46 47 int mem_init_done; 48 49 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 50 51 static void __init zone_sizes_init(void) 52 { 53 unsigned long zones_size[MAX_NR_ZONES]; 54 55 /* Clear the zone sizes */ 56 memset(zones_size, 0, sizeof(zones_size)); 57 58 /* 59 * We use only ZONE_NORMAL 60 */ 61 zones_size[ZONE_NORMAL] = max_low_pfn; 62 63 free_area_init(zones_size); 64 } 65 66 extern const char _s_kernel_ro[], _e_kernel_ro[]; 67 68 /* 69 * Map all physical memory into kernel's address space. 70 * 71 * This is explicitly coded for two-level page tables, so if you need 72 * something else then this needs to change. 73 */ 74 static void __init map_ram(void) 75 { 76 unsigned long v, p, e; 77 pgprot_t prot; 78 pgd_t *pge; 79 pud_t *pue; 80 pmd_t *pme; 81 pte_t *pte; 82 /* These mark extents of read-only kernel pages... 83 * ...from vmlinux.lds.S 84 */ 85 struct memblock_region *region; 86 87 v = PAGE_OFFSET; 88 89 for_each_memblock(memory, region) { 90 p = (u32) region->base & PAGE_MASK; 91 e = p + (u32) region->size; 92 93 v = (u32) __va(p); 94 pge = pgd_offset_k(v); 95 96 while (p < e) { 97 int j; 98 pue = pud_offset(pge, v); 99 pme = pmd_offset(pue, v); 100 101 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) { 102 panic("%s: OR1K kernel hardcoded for " 103 "two-level page tables", 104 __func__); 105 } 106 107 /* Alloc one page for holding PTE's... */ 108 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 109 set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte))); 110 111 /* Fill the newly allocated page with PTE'S */ 112 for (j = 0; p < e && j < PTRS_PER_PGD; 113 v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) { 114 if (v >= (u32) _e_kernel_ro || 115 v < (u32) _s_kernel_ro) 116 prot = PAGE_KERNEL; 117 else 118 prot = PAGE_KERNEL_RO; 119 120 set_pte(pte, mk_pte_phys(p, prot)); 121 } 122 123 pge++; 124 } 125 126 printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__, 127 region->base, region->base + region->size); 128 } 129 } 130 131 void __init paging_init(void) 132 { 133 extern void tlb_init(void); 134 135 unsigned long end; 136 int i; 137 138 printk(KERN_INFO "Setting up paging and PTEs.\n"); 139 140 /* clear out the init_mm.pgd that will contain the kernel's mappings */ 141 142 for (i = 0; i < PTRS_PER_PGD; i++) 143 swapper_pg_dir[i] = __pgd(0); 144 145 /* make sure the current pgd table points to something sane 146 * (even if it is most probably not used until the next 147 * switch_mm) 148 */ 149 current_pgd = init_mm.pgd; 150 151 end = (unsigned long)__va(max_low_pfn * PAGE_SIZE); 152 153 map_ram(); 154 155 zone_sizes_init(); 156 157 /* self modifying code ;) */ 158 /* Since the old TLB miss handler has been running up until now, 159 * the kernel pages are still all RW, so we can still modify the 160 * text directly... after this change and a TLB flush, the kernel 161 * pages will become RO. 162 */ 163 { 164 extern unsigned long dtlb_miss_handler; 165 extern unsigned long itlb_miss_handler; 166 167 unsigned long *dtlb_vector = __va(0x900); 168 unsigned long *itlb_vector = __va(0xa00); 169 170 printk(KERN_INFO "itlb_miss_handler %p\n", &itlb_miss_handler); 171 *itlb_vector = ((unsigned long)&itlb_miss_handler - 172 (unsigned long)itlb_vector) >> 2; 173 174 /* Soft ordering constraint to ensure that dtlb_vector is 175 * the last thing updated 176 */ 177 barrier(); 178 179 printk(KERN_INFO "dtlb_miss_handler %p\n", &dtlb_miss_handler); 180 *dtlb_vector = ((unsigned long)&dtlb_miss_handler - 181 (unsigned long)dtlb_vector) >> 2; 182 183 } 184 185 /* Soft ordering constraint to ensure that cache invalidation and 186 * TLB flush really happen _after_ code has been modified. 187 */ 188 barrier(); 189 190 /* Invalidate instruction caches after code modification */ 191 mtspr(SPR_ICBIR, 0x900); 192 mtspr(SPR_ICBIR, 0xa00); 193 194 /* New TLB miss handlers and kernel page tables are in now place. 195 * Make sure that page flags get updated for all pages in TLB by 196 * flushing the TLB and forcing all TLB entries to be recreated 197 * from their page table flags. 198 */ 199 flush_tlb_all(); 200 } 201 202 /* References to section boundaries */ 203 204 extern char _stext, _etext, _edata, __bss_start, _end; 205 extern char __init_begin, __init_end; 206 207 static int __init free_pages_init(void) 208 { 209 int reservedpages, pfn; 210 211 /* this will put all low memory onto the freelists */ 212 totalram_pages = free_all_bootmem(); 213 214 reservedpages = 0; 215 for (pfn = 0; pfn < max_low_pfn; pfn++) { 216 /* 217 * Only count reserved RAM pages 218 */ 219 if (PageReserved(mem_map + pfn)) 220 reservedpages++; 221 } 222 223 return reservedpages; 224 } 225 226 static void __init set_max_mapnr_init(void) 227 { 228 max_mapnr = num_physpages = max_low_pfn; 229 } 230 231 void __init mem_init(void) 232 { 233 int codesize, reservedpages, datasize, initsize; 234 235 BUG_ON(!mem_map); 236 237 set_max_mapnr_init(); 238 239 high_memory = (void *)__va(max_low_pfn * PAGE_SIZE); 240 241 /* clear the zero-page */ 242 memset((void *)empty_zero_page, 0, PAGE_SIZE); 243 244 reservedpages = free_pages_init(); 245 246 codesize = (unsigned long)&_etext - (unsigned long)&_stext; 247 datasize = (unsigned long)&_edata - (unsigned long)&_etext; 248 initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin; 249 250 printk(KERN_INFO 251 "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n", 252 (unsigned long)nr_free_pages() << (PAGE_SHIFT - 10), 253 max_mapnr << (PAGE_SHIFT - 10), codesize >> 10, 254 reservedpages << (PAGE_SHIFT - 10), datasize >> 10, 255 initsize >> 10, (unsigned long)(0 << (PAGE_SHIFT - 10)) 256 ); 257 258 printk("mem_init_done ...........................................\n"); 259 mem_init_done = 1; 260 return; 261 } 262 263 #ifdef CONFIG_BLK_DEV_INITRD 264 void free_initrd_mem(unsigned long start, unsigned long end) 265 { 266 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n", 267 (end - start) >> 10); 268 269 for (; start < end; start += PAGE_SIZE) { 270 ClearPageReserved(virt_to_page(start)); 271 init_page_count(virt_to_page(start)); 272 free_page(start); 273 totalram_pages++; 274 } 275 } 276 #endif 277 278 void free_initmem(void) 279 { 280 unsigned long addr; 281 282 addr = (unsigned long)(&__init_begin); 283 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 284 ClearPageReserved(virt_to_page(addr)); 285 init_page_count(virt_to_page(addr)); 286 free_page(addr); 287 totalram_pages++; 288 } 289 printk(KERN_INFO "Freeing unused kernel memory: %luk freed\n", 290 ((unsigned long)&__init_end - 291 (unsigned long)&__init_begin) >> 10); 292 } 293