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