1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * S390 version 4 * Copyright IBM Corp. 1999 5 * Author(s): Hartmut Penner (hp@de.ibm.com) 6 * 7 * Derived from "arch/i386/mm/init.c" 8 * Copyright (C) 1995 Linus Torvalds 9 */ 10 11 #include <linux/signal.h> 12 #include <linux/sched.h> 13 #include <linux/kernel.h> 14 #include <linux/errno.h> 15 #include <linux/string.h> 16 #include <linux/types.h> 17 #include <linux/ptrace.h> 18 #include <linux/mman.h> 19 #include <linux/mm.h> 20 #include <linux/swap.h> 21 #include <linux/smp.h> 22 #include <linux/init.h> 23 #include <linux/pagemap.h> 24 #include <linux/memblock.h> 25 #include <linux/memory.h> 26 #include <linux/pfn.h> 27 #include <linux/poison.h> 28 #include <linux/initrd.h> 29 #include <linux/export.h> 30 #include <linux/cma.h> 31 #include <linux/gfp.h> 32 #include <asm/processor.h> 33 #include <linux/uaccess.h> 34 #include <asm/pgtable.h> 35 #include <asm/pgalloc.h> 36 #include <asm/dma.h> 37 #include <asm/lowcore.h> 38 #include <asm/tlb.h> 39 #include <asm/tlbflush.h> 40 #include <asm/sections.h> 41 #include <asm/ctl_reg.h> 42 #include <asm/sclp.h> 43 #include <asm/set_memory.h> 44 #include <asm/kasan.h> 45 46 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir); 47 48 unsigned long empty_zero_page, zero_page_mask; 49 EXPORT_SYMBOL(empty_zero_page); 50 EXPORT_SYMBOL(zero_page_mask); 51 52 bool initmem_freed; 53 54 static void __init setup_zero_pages(void) 55 { 56 unsigned int order; 57 struct page *page; 58 int i; 59 60 /* Latest machines require a mapping granularity of 512KB */ 61 order = 7; 62 63 /* Limit number of empty zero pages for small memory sizes */ 64 while (order > 2 && (totalram_pages() >> 10) < (1UL << order)) 65 order--; 66 67 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); 68 if (!empty_zero_page) 69 panic("Out of memory in setup_zero_pages"); 70 71 page = virt_to_page((void *) empty_zero_page); 72 split_page(page, order); 73 for (i = 1 << order; i > 0; i--) { 74 mark_page_reserved(page); 75 page++; 76 } 77 78 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; 79 } 80 81 /* 82 * paging_init() sets up the page tables 83 */ 84 void __init paging_init(void) 85 { 86 unsigned long max_zone_pfns[MAX_NR_ZONES]; 87 unsigned long pgd_type, asce_bits; 88 psw_t psw; 89 90 init_mm.pgd = swapper_pg_dir; 91 if (VMALLOC_END > _REGION2_SIZE) { 92 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; 93 pgd_type = _REGION2_ENTRY_EMPTY; 94 } else { 95 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 96 pgd_type = _REGION3_ENTRY_EMPTY; 97 } 98 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits; 99 S390_lowcore.kernel_asce = init_mm.context.asce; 100 S390_lowcore.user_asce = S390_lowcore.kernel_asce; 101 crst_table_init((unsigned long *) init_mm.pgd, pgd_type); 102 vmem_map_init(); 103 kasan_copy_shadow(init_mm.pgd); 104 105 /* enable virtual mapping in kernel mode */ 106 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 107 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 108 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 109 psw.mask = __extract_psw(); 110 psw_bits(psw).dat = 1; 111 psw_bits(psw).as = PSW_BITS_AS_HOME; 112 __load_psw_mask(psw.mask); 113 kasan_free_early_identity(); 114 115 sparse_memory_present_with_active_regions(MAX_NUMNODES); 116 sparse_init(); 117 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 118 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 119 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 120 free_area_init_nodes(max_zone_pfns); 121 } 122 123 void mark_rodata_ro(void) 124 { 125 unsigned long size = __end_ro_after_init - __start_ro_after_init; 126 127 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT); 128 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); 129 } 130 131 void __init mem_init(void) 132 { 133 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); 134 cpumask_set_cpu(0, mm_cpumask(&init_mm)); 135 136 set_max_mapnr(max_low_pfn); 137 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 138 139 /* Setup guest page hinting */ 140 cmma_init(); 141 142 /* this will put all low memory onto the freelists */ 143 memblock_free_all(); 144 setup_zero_pages(); /* Setup zeroed pages. */ 145 146 cmma_init_nodat(); 147 148 mem_init_print_info(NULL); 149 } 150 151 void free_initmem(void) 152 { 153 initmem_freed = true; 154 __set_memory((unsigned long)_sinittext, 155 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT, 156 SET_MEMORY_RW | SET_MEMORY_NX); 157 free_initmem_default(POISON_FREE_INITMEM); 158 } 159 160 unsigned long memory_block_size_bytes(void) 161 { 162 /* 163 * Make sure the memory block size is always greater 164 * or equal than the memory increment size. 165 */ 166 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm); 167 } 168 169 #ifdef CONFIG_MEMORY_HOTPLUG 170 171 #ifdef CONFIG_CMA 172 173 /* Prevent memory blocks which contain cma regions from going offline */ 174 175 struct s390_cma_mem_data { 176 unsigned long start; 177 unsigned long end; 178 }; 179 180 static int s390_cma_check_range(struct cma *cma, void *data) 181 { 182 struct s390_cma_mem_data *mem_data; 183 unsigned long start, end; 184 185 mem_data = data; 186 start = cma_get_base(cma); 187 end = start + cma_get_size(cma); 188 if (end < mem_data->start) 189 return 0; 190 if (start >= mem_data->end) 191 return 0; 192 return -EBUSY; 193 } 194 195 static int s390_cma_mem_notifier(struct notifier_block *nb, 196 unsigned long action, void *data) 197 { 198 struct s390_cma_mem_data mem_data; 199 struct memory_notify *arg; 200 int rc = 0; 201 202 arg = data; 203 mem_data.start = arg->start_pfn << PAGE_SHIFT; 204 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT); 205 if (action == MEM_GOING_OFFLINE) 206 rc = cma_for_each_area(s390_cma_check_range, &mem_data); 207 return notifier_from_errno(rc); 208 } 209 210 static struct notifier_block s390_cma_mem_nb = { 211 .notifier_call = s390_cma_mem_notifier, 212 }; 213 214 static int __init s390_cma_mem_init(void) 215 { 216 return register_memory_notifier(&s390_cma_mem_nb); 217 } 218 device_initcall(s390_cma_mem_init); 219 220 #endif /* CONFIG_CMA */ 221 222 int arch_add_memory(int nid, u64 start, u64 size, 223 struct mhp_restrictions *restrictions) 224 { 225 unsigned long start_pfn = PFN_DOWN(start); 226 unsigned long size_pages = PFN_DOWN(size); 227 int rc; 228 229 rc = vmem_add_mapping(start, size); 230 if (rc) 231 return rc; 232 233 rc = __add_pages(nid, start_pfn, size_pages, restrictions); 234 if (rc) 235 vmem_remove_mapping(start, size); 236 return rc; 237 } 238 239 #ifdef CONFIG_MEMORY_HOTREMOVE 240 void arch_remove_memory(int nid, u64 start, u64 size, 241 struct vmem_altmap *altmap) 242 { 243 /* 244 * There is no hardware or firmware interface which could trigger a 245 * hot memory remove on s390. So there is nothing that needs to be 246 * implemented. 247 */ 248 BUG(); 249 } 250 #endif 251 #endif /* CONFIG_MEMORY_HOTPLUG */ 252