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 <linux/memblock.h> 31 #include <asm/processor.h> 32 #include <asm/uaccess.h> 33 #include <asm/pgtable.h> 34 #include <asm/pgalloc.h> 35 #include <asm/dma.h> 36 #include <asm/lowcore.h> 37 #include <asm/tlb.h> 38 #include <asm/tlbflush.h> 39 #include <asm/sections.h> 40 #include <asm/ctl_reg.h> 41 #include <asm/sclp.h> 42 43 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE))); 44 45 unsigned long empty_zero_page, zero_page_mask; 46 EXPORT_SYMBOL(empty_zero_page); 47 EXPORT_SYMBOL(zero_page_mask); 48 49 static void __init setup_zero_pages(void) 50 { 51 unsigned int order; 52 struct page *page; 53 int i; 54 55 /* Latest machines require a mapping granularity of 512KB */ 56 order = 7; 57 58 /* Limit number of empty zero pages for small memory sizes */ 59 while (order > 2 && (totalram_pages >> 10) < (1UL << order)) 60 order--; 61 62 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); 63 if (!empty_zero_page) 64 panic("Out of memory in setup_zero_pages"); 65 66 page = virt_to_page((void *) empty_zero_page); 67 split_page(page, order); 68 for (i = 1 << order; i > 0; i--) { 69 mark_page_reserved(page); 70 page++; 71 } 72 73 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; 74 } 75 76 /* 77 * paging_init() sets up the page tables 78 */ 79 void __init paging_init(void) 80 { 81 unsigned long max_zone_pfns[MAX_NR_ZONES]; 82 unsigned long pgd_type, asce_bits; 83 84 init_mm.pgd = swapper_pg_dir; 85 if (VMALLOC_END > (1UL << 42)) { 86 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; 87 pgd_type = _REGION2_ENTRY_EMPTY; 88 } else { 89 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 90 pgd_type = _REGION3_ENTRY_EMPTY; 91 } 92 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits; 93 S390_lowcore.kernel_asce = init_mm.context.asce; 94 clear_table((unsigned long *) init_mm.pgd, pgd_type, 95 sizeof(unsigned long)*2048); 96 vmem_map_init(); 97 98 /* enable virtual mapping in kernel mode */ 99 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 100 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 101 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 102 __arch_local_irq_stosm(0x04); 103 104 sparse_memory_present_with_active_regions(MAX_NUMNODES); 105 sparse_init(); 106 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 107 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 108 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 109 free_area_init_nodes(max_zone_pfns); 110 } 111 112 void mark_rodata_ro(void) 113 { 114 /* Text and rodata are already protected. Nothing to do here. */ 115 pr_info("Write protecting the kernel read-only data: %luk\n", 116 ((unsigned long)&_eshared - (unsigned long)&_stext) >> 10); 117 } 118 119 void __init mem_init(void) 120 { 121 if (MACHINE_HAS_TLB_LC) 122 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); 123 cpumask_set_cpu(0, mm_cpumask(&init_mm)); 124 atomic_set(&init_mm.context.attach_count, 1); 125 126 set_max_mapnr(max_low_pfn); 127 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 128 129 /* Setup guest page hinting */ 130 cmma_init(); 131 132 /* this will put all low memory onto the freelists */ 133 free_all_bootmem(); 134 setup_zero_pages(); /* Setup zeroed pages. */ 135 136 mem_init_print_info(NULL); 137 } 138 139 void free_initmem(void) 140 { 141 free_initmem_default(POISON_FREE_INITMEM); 142 } 143 144 #ifdef CONFIG_BLK_DEV_INITRD 145 void __init free_initrd_mem(unsigned long start, unsigned long end) 146 { 147 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM, 148 "initrd"); 149 } 150 #endif 151 152 #ifdef CONFIG_MEMORY_HOTPLUG 153 int arch_add_memory(int nid, u64 start, u64 size, bool for_device) 154 { 155 unsigned long normal_end_pfn = PFN_DOWN(memblock_end_of_DRAM()); 156 unsigned long dma_end_pfn = PFN_DOWN(MAX_DMA_ADDRESS); 157 unsigned long start_pfn = PFN_DOWN(start); 158 unsigned long size_pages = PFN_DOWN(size); 159 unsigned long nr_pages; 160 int rc, zone_enum; 161 162 rc = vmem_add_mapping(start, size); 163 if (rc) 164 return rc; 165 166 while (size_pages > 0) { 167 if (start_pfn < dma_end_pfn) { 168 nr_pages = (start_pfn + size_pages > dma_end_pfn) ? 169 dma_end_pfn - start_pfn : size_pages; 170 zone_enum = ZONE_DMA; 171 } else if (start_pfn < normal_end_pfn) { 172 nr_pages = (start_pfn + size_pages > normal_end_pfn) ? 173 normal_end_pfn - start_pfn : size_pages; 174 zone_enum = ZONE_NORMAL; 175 } else { 176 nr_pages = size_pages; 177 zone_enum = ZONE_MOVABLE; 178 } 179 rc = __add_pages(nid, NODE_DATA(nid)->node_zones + zone_enum, 180 start_pfn, size_pages); 181 if (rc) 182 break; 183 start_pfn += nr_pages; 184 size_pages -= nr_pages; 185 } 186 if (rc) 187 vmem_remove_mapping(start, size); 188 return rc; 189 } 190 191 unsigned long memory_block_size_bytes(void) 192 { 193 /* 194 * Make sure the memory block size is always greater 195 * or equal than the memory increment size. 196 */ 197 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm); 198 } 199 200 #ifdef CONFIG_MEMORY_HOTREMOVE 201 int arch_remove_memory(u64 start, u64 size) 202 { 203 /* 204 * There is no hardware or firmware interface which could trigger a 205 * hot memory remove on s390. So there is nothing that needs to be 206 * implemented. 207 */ 208 return -EBUSY; 209 } 210 #endif 211 #endif /* CONFIG_MEMORY_HOTPLUG */ 212