1 /* 2 * arch/s390/mm/init.c 3 * 4 * S390 version 5 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation 6 * Author(s): Hartmut Penner (hp@de.ibm.com) 7 * 8 * Derived from "arch/i386/mm/init.c" 9 * Copyright (C) 1995 Linus Torvalds 10 */ 11 12 #include <linux/signal.h> 13 #include <linux/sched.h> 14 #include <linux/kernel.h> 15 #include <linux/errno.h> 16 #include <linux/string.h> 17 #include <linux/types.h> 18 #include <linux/ptrace.h> 19 #include <linux/mman.h> 20 #include <linux/mm.h> 21 #include <linux/swap.h> 22 #include <linux/smp.h> 23 #include <linux/init.h> 24 #include <linux/pagemap.h> 25 #include <linux/bootmem.h> 26 #include <linux/pfn.h> 27 #include <linux/poison.h> 28 #include <linux/initrd.h> 29 #include <asm/processor.h> 30 #include <asm/system.h> 31 #include <asm/uaccess.h> 32 #include <asm/pgtable.h> 33 #include <asm/pgalloc.h> 34 #include <asm/dma.h> 35 #include <asm/lowcore.h> 36 #include <asm/tlb.h> 37 #include <asm/tlbflush.h> 38 #include <asm/sections.h> 39 40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 41 42 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE))); 43 char empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 44 45 void show_mem(void) 46 { 47 int i, total = 0, reserved = 0; 48 int shared = 0, cached = 0; 49 struct page *page; 50 51 printk("Mem-info:\n"); 52 show_free_areas(); 53 printk("Free swap: %6ldkB\n", nr_swap_pages << (PAGE_SHIFT - 10)); 54 i = max_mapnr; 55 while (i-- > 0) { 56 if (!pfn_valid(i)) 57 continue; 58 page = pfn_to_page(i); 59 total++; 60 if (PageReserved(page)) 61 reserved++; 62 else if (PageSwapCache(page)) 63 cached++; 64 else if (page_count(page)) 65 shared += page_count(page) - 1; 66 } 67 printk("%d pages of RAM\n", total); 68 printk("%d reserved pages\n", reserved); 69 printk("%d pages shared\n", shared); 70 printk("%d pages swap cached\n", cached); 71 72 printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY)); 73 printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK)); 74 printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED)); 75 printk("%lu pages slab\n", 76 global_page_state(NR_SLAB_RECLAIMABLE) + 77 global_page_state(NR_SLAB_UNRECLAIMABLE)); 78 printk("%lu pages pagetables\n", global_page_state(NR_PAGETABLE)); 79 } 80 81 static void __init setup_ro_region(void) 82 { 83 pgd_t *pgd; 84 pud_t *pud; 85 pmd_t *pmd; 86 pte_t *pte; 87 pte_t new_pte; 88 unsigned long address, end; 89 90 address = ((unsigned long)&_stext) & PAGE_MASK; 91 end = PFN_ALIGN((unsigned long)&_eshared); 92 93 for (; address < end; address += PAGE_SIZE) { 94 pgd = pgd_offset_k(address); 95 pud = pud_offset(pgd, address); 96 pmd = pmd_offset(pud, address); 97 pte = pte_offset_kernel(pmd, address); 98 new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO)); 99 *pte = new_pte; 100 } 101 } 102 103 /* 104 * paging_init() sets up the page tables 105 */ 106 void __init paging_init(void) 107 { 108 static const int ssm_mask = 0x04000000L; 109 unsigned long max_zone_pfns[MAX_NR_ZONES]; 110 unsigned long pgd_type; 111 112 init_mm.pgd = swapper_pg_dir; 113 S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK; 114 #ifdef CONFIG_64BIT 115 /* A three level page table (4TB) is enough for the kernel space. */ 116 S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 117 pgd_type = _REGION3_ENTRY_EMPTY; 118 #else 119 S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH; 120 pgd_type = _SEGMENT_ENTRY_EMPTY; 121 #endif 122 clear_table((unsigned long *) init_mm.pgd, pgd_type, 123 sizeof(unsigned long)*2048); 124 vmem_map_init(); 125 setup_ro_region(); 126 127 /* enable virtual mapping in kernel mode */ 128 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 129 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 130 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 131 __raw_local_irq_ssm(ssm_mask); 132 133 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 134 #ifdef CONFIG_ZONE_DMA 135 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 136 #endif 137 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 138 free_area_init_nodes(max_zone_pfns); 139 } 140 141 void __init mem_init(void) 142 { 143 unsigned long codesize, reservedpages, datasize, initsize; 144 145 max_mapnr = num_physpages = max_low_pfn; 146 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 147 148 /* clear the zero-page */ 149 memset(empty_zero_page, 0, PAGE_SIZE); 150 151 /* this will put all low memory onto the freelists */ 152 totalram_pages += free_all_bootmem(); 153 154 reservedpages = 0; 155 156 codesize = (unsigned long) &_etext - (unsigned long) &_text; 157 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 158 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 159 printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n", 160 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 161 max_mapnr << (PAGE_SHIFT-10), 162 codesize >> 10, 163 reservedpages << (PAGE_SHIFT-10), 164 datasize >>10, 165 initsize >> 10); 166 printk("Write protected kernel read-only data: %#lx - %#lx\n", 167 (unsigned long)&_stext, 168 PFN_ALIGN((unsigned long)&_eshared) - 1); 169 } 170 171 #ifdef CONFIG_DEBUG_PAGEALLOC 172 void kernel_map_pages(struct page *page, int numpages, int enable) 173 { 174 pgd_t *pgd; 175 pud_t *pud; 176 pmd_t *pmd; 177 pte_t *pte; 178 unsigned long address; 179 int i; 180 181 for (i = 0; i < numpages; i++) { 182 address = page_to_phys(page + i); 183 pgd = pgd_offset_k(address); 184 pud = pud_offset(pgd, address); 185 pmd = pmd_offset(pud, address); 186 pte = pte_offset_kernel(pmd, address); 187 if (!enable) { 188 ptep_invalidate(&init_mm, address, pte); 189 continue; 190 } 191 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW)); 192 /* Flush cpu write queue. */ 193 mb(); 194 } 195 } 196 #endif 197 198 void free_initmem(void) 199 { 200 unsigned long addr; 201 202 addr = (unsigned long)(&__init_begin); 203 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 204 ClearPageReserved(virt_to_page(addr)); 205 init_page_count(virt_to_page(addr)); 206 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); 207 free_page(addr); 208 totalram_pages++; 209 } 210 printk ("Freeing unused kernel memory: %ldk freed\n", 211 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10); 212 } 213 214 #ifdef CONFIG_BLK_DEV_INITRD 215 void free_initrd_mem(unsigned long start, unsigned long end) 216 { 217 if (start < end) 218 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 219 for (; start < end; start += PAGE_SIZE) { 220 ClearPageReserved(virt_to_page(start)); 221 init_page_count(virt_to_page(start)); 222 free_page(start); 223 totalram_pages++; 224 } 225 } 226 #endif 227