1 /* 2 * S390 version 3 * Copyright IBM Corp. 1999 4 * Author(s): Hartmut Penner (hp@de.ibm.com) 5 * 6 * Derived from "arch/i386/mm/init.c" 7 * Copyright (C) 1995 Linus Torvalds 8 */ 9 10 #include <linux/signal.h> 11 #include <linux/sched.h> 12 #include <linux/kernel.h> 13 #include <linux/errno.h> 14 #include <linux/string.h> 15 #include <linux/types.h> 16 #include <linux/ptrace.h> 17 #include <linux/mman.h> 18 #include <linux/mm.h> 19 #include <linux/swap.h> 20 #include <linux/smp.h> 21 #include <linux/init.h> 22 #include <linux/pagemap.h> 23 #include <linux/bootmem.h> 24 #include <linux/memory.h> 25 #include <linux/pfn.h> 26 #include <linux/poison.h> 27 #include <linux/initrd.h> 28 #include <linux/export.h> 29 #include <linux/gfp.h> 30 #include <asm/processor.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 #include <asm/ctl_reg.h> 40 #include <asm/sclp.h> 41 42 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE))); 43 44 unsigned long empty_zero_page, zero_page_mask; 45 EXPORT_SYMBOL(empty_zero_page); 46 47 static void __init setup_zero_pages(void) 48 { 49 struct cpuid cpu_id; 50 unsigned int order; 51 struct page *page; 52 int i; 53 54 get_cpu_id(&cpu_id); 55 switch (cpu_id.machine) { 56 case 0x9672: /* g5 */ 57 case 0x2064: /* z900 */ 58 case 0x2066: /* z900 */ 59 case 0x2084: /* z990 */ 60 case 0x2086: /* z990 */ 61 case 0x2094: /* z9-109 */ 62 case 0x2096: /* z9-109 */ 63 order = 0; 64 break; 65 case 0x2097: /* z10 */ 66 case 0x2098: /* z10 */ 67 case 0x2817: /* z196 */ 68 case 0x2818: /* z196 */ 69 order = 2; 70 break; 71 case 0x2827: /* zEC12 */ 72 case 0x2828: /* zEC12 */ 73 default: 74 order = 5; 75 break; 76 } 77 /* Limit number of empty zero pages for small memory sizes */ 78 if (order > 2 && totalram_pages <= 16384) 79 order = 2; 80 81 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); 82 if (!empty_zero_page) 83 panic("Out of memory in setup_zero_pages"); 84 85 page = virt_to_page((void *) empty_zero_page); 86 split_page(page, order); 87 for (i = 1 << order; i > 0; i--) { 88 mark_page_reserved(page); 89 page++; 90 } 91 92 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; 93 } 94 95 /* 96 * paging_init() sets up the page tables 97 */ 98 void __init paging_init(void) 99 { 100 unsigned long max_zone_pfns[MAX_NR_ZONES]; 101 unsigned long pgd_type, asce_bits; 102 103 init_mm.pgd = swapper_pg_dir; 104 #ifdef CONFIG_64BIT 105 if (VMALLOC_END > (1UL << 42)) { 106 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; 107 pgd_type = _REGION2_ENTRY_EMPTY; 108 } else { 109 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 110 pgd_type = _REGION3_ENTRY_EMPTY; 111 } 112 #else 113 asce_bits = _ASCE_TABLE_LENGTH; 114 pgd_type = _SEGMENT_ENTRY_EMPTY; 115 #endif 116 S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits; 117 clear_table((unsigned long *) init_mm.pgd, pgd_type, 118 sizeof(unsigned long)*2048); 119 vmem_map_init(); 120 121 /* enable virtual mapping in kernel mode */ 122 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 123 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 124 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 125 arch_local_irq_restore(4UL << (BITS_PER_LONG - 8)); 126 127 atomic_set(&init_mm.context.attach_count, 1); 128 129 sparse_memory_present_with_active_regions(MAX_NUMNODES); 130 sparse_init(); 131 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 132 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 133 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 134 free_area_init_nodes(max_zone_pfns); 135 } 136 137 void __init mem_init(void) 138 { 139 max_mapnr = max_low_pfn; 140 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 141 142 /* Setup guest page hinting */ 143 cmma_init(); 144 145 /* this will put all low memory onto the freelists */ 146 free_all_bootmem(); 147 setup_zero_pages(); /* Setup zeroed pages. */ 148 149 mem_init_print_info(NULL); 150 printk("Write protected kernel read-only data: %#lx - %#lx\n", 151 (unsigned long)&_stext, 152 PFN_ALIGN((unsigned long)&_eshared) - 1); 153 } 154 155 void free_initmem(void) 156 { 157 free_initmem_default(POISON_FREE_INITMEM); 158 } 159 160 #ifdef CONFIG_BLK_DEV_INITRD 161 void __init free_initrd_mem(unsigned long start, unsigned long end) 162 { 163 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM, 164 "initrd"); 165 } 166 #endif 167 168 #ifdef CONFIG_MEMORY_HOTPLUG 169 int arch_add_memory(int nid, u64 start, u64 size) 170 { 171 unsigned long zone_start_pfn, zone_end_pfn, nr_pages; 172 unsigned long start_pfn = PFN_DOWN(start); 173 unsigned long size_pages = PFN_DOWN(size); 174 struct zone *zone; 175 int rc; 176 177 rc = vmem_add_mapping(start, size); 178 if (rc) 179 return rc; 180 for_each_zone(zone) { 181 if (zone_idx(zone) != ZONE_MOVABLE) { 182 /* Add range within existing zone limits */ 183 zone_start_pfn = zone->zone_start_pfn; 184 zone_end_pfn = zone->zone_start_pfn + 185 zone->spanned_pages; 186 } else { 187 /* Add remaining range to ZONE_MOVABLE */ 188 zone_start_pfn = start_pfn; 189 zone_end_pfn = start_pfn + size_pages; 190 } 191 if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn) 192 continue; 193 nr_pages = (start_pfn + size_pages > zone_end_pfn) ? 194 zone_end_pfn - start_pfn : size_pages; 195 rc = __add_pages(nid, zone, start_pfn, nr_pages); 196 if (rc) 197 break; 198 start_pfn += nr_pages; 199 size_pages -= nr_pages; 200 if (!size_pages) 201 break; 202 } 203 if (rc) 204 vmem_remove_mapping(start, size); 205 return rc; 206 } 207 208 unsigned long memory_block_size_bytes(void) 209 { 210 /* 211 * Make sure the memory block size is always greater 212 * or equal than the memory increment size. 213 */ 214 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp_get_rzm()); 215 } 216 217 #ifdef CONFIG_MEMORY_HOTREMOVE 218 int arch_remove_memory(u64 start, u64 size) 219 { 220 /* 221 * There is no hardware or firmware interface which could trigger a 222 * hot memory remove on s390. So there is nothing that needs to be 223 * implemented. 224 */ 225 return -EBUSY; 226 } 227 #endif 228 #endif /* CONFIG_MEMORY_HOTPLUG */ 229