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/bootmem.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 <linux/memblock.h> 33 #include <asm/processor.h> 34 #include <linux/uaccess.h> 35 #include <asm/pgtable.h> 36 #include <asm/pgalloc.h> 37 #include <asm/dma.h> 38 #include <asm/lowcore.h> 39 #include <asm/tlb.h> 40 #include <asm/tlbflush.h> 41 #include <asm/sections.h> 42 #include <asm/ctl_reg.h> 43 #include <asm/sclp.h> 44 #include <asm/set_memory.h> 45 #include <asm/kasan.h> 46 47 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir); 48 49 unsigned long empty_zero_page, zero_page_mask; 50 EXPORT_SYMBOL(empty_zero_page); 51 EXPORT_SYMBOL(zero_page_mask); 52 53 static void __init setup_zero_pages(void) 54 { 55 unsigned int order; 56 struct page *page; 57 int i; 58 59 /* Latest machines require a mapping granularity of 512KB */ 60 order = 7; 61 62 /* Limit number of empty zero pages for small memory sizes */ 63 while (order > 2 && (totalram_pages >> 10) < (1UL << order)) 64 order--; 65 66 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); 67 if (!empty_zero_page) 68 panic("Out of memory in setup_zero_pages"); 69 70 page = virt_to_page((void *) empty_zero_page); 71 split_page(page, order); 72 for (i = 1 << order; i > 0; i--) { 73 mark_page_reserved(page); 74 page++; 75 } 76 77 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; 78 } 79 80 /* 81 * paging_init() sets up the page tables 82 */ 83 void __init paging_init(void) 84 { 85 unsigned long max_zone_pfns[MAX_NR_ZONES]; 86 unsigned long pgd_type, asce_bits; 87 psw_t psw; 88 89 init_mm.pgd = swapper_pg_dir; 90 if (VMALLOC_END > _REGION2_SIZE) { 91 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; 92 pgd_type = _REGION2_ENTRY_EMPTY; 93 } else { 94 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 95 pgd_type = _REGION3_ENTRY_EMPTY; 96 } 97 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits; 98 S390_lowcore.kernel_asce = init_mm.context.asce; 99 S390_lowcore.user_asce = S390_lowcore.kernel_asce; 100 crst_table_init((unsigned long *) init_mm.pgd, pgd_type); 101 vmem_map_init(); 102 kasan_copy_shadow(init_mm.pgd); 103 104 /* enable virtual mapping in kernel mode */ 105 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 106 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 107 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 108 psw.mask = __extract_psw(); 109 psw_bits(psw).dat = 1; 110 psw_bits(psw).as = PSW_BITS_AS_HOME; 111 __load_psw_mask(psw.mask); 112 kasan_free_early_identity(); 113 114 sparse_memory_present_with_active_regions(MAX_NUMNODES); 115 sparse_init(); 116 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 117 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 118 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 119 free_area_init_nodes(max_zone_pfns); 120 } 121 122 void mark_rodata_ro(void) 123 { 124 unsigned long size = __end_ro_after_init - __start_ro_after_init; 125 126 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT); 127 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); 128 } 129 130 void __init mem_init(void) 131 { 132 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); 133 cpumask_set_cpu(0, mm_cpumask(&init_mm)); 134 135 set_max_mapnr(max_low_pfn); 136 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 137 138 /* Setup guest page hinting */ 139 cmma_init(); 140 141 /* this will put all low memory onto the freelists */ 142 free_all_bootmem(); 143 setup_zero_pages(); /* Setup zeroed pages. */ 144 145 cmma_init_nodat(); 146 147 mem_init_print_info(NULL); 148 } 149 150 void free_initmem(void) 151 { 152 __set_memory((unsigned long)_sinittext, 153 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT, 154 SET_MEMORY_RW | SET_MEMORY_NX); 155 free_initmem_default(POISON_FREE_INITMEM); 156 } 157 158 #ifdef CONFIG_BLK_DEV_INITRD 159 void __init free_initrd_mem(unsigned long start, unsigned long end) 160 { 161 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM, 162 "initrd"); 163 } 164 #endif 165 166 unsigned long memory_block_size_bytes(void) 167 { 168 /* 169 * Make sure the memory block size is always greater 170 * or equal than the memory increment size. 171 */ 172 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm); 173 } 174 175 #ifdef CONFIG_MEMORY_HOTPLUG 176 177 #ifdef CONFIG_CMA 178 179 /* Prevent memory blocks which contain cma regions from going offline */ 180 181 struct s390_cma_mem_data { 182 unsigned long start; 183 unsigned long end; 184 }; 185 186 static int s390_cma_check_range(struct cma *cma, void *data) 187 { 188 struct s390_cma_mem_data *mem_data; 189 unsigned long start, end; 190 191 mem_data = data; 192 start = cma_get_base(cma); 193 end = start + cma_get_size(cma); 194 if (end < mem_data->start) 195 return 0; 196 if (start >= mem_data->end) 197 return 0; 198 return -EBUSY; 199 } 200 201 static int s390_cma_mem_notifier(struct notifier_block *nb, 202 unsigned long action, void *data) 203 { 204 struct s390_cma_mem_data mem_data; 205 struct memory_notify *arg; 206 int rc = 0; 207 208 arg = data; 209 mem_data.start = arg->start_pfn << PAGE_SHIFT; 210 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT); 211 if (action == MEM_GOING_OFFLINE) 212 rc = cma_for_each_area(s390_cma_check_range, &mem_data); 213 return notifier_from_errno(rc); 214 } 215 216 static struct notifier_block s390_cma_mem_nb = { 217 .notifier_call = s390_cma_mem_notifier, 218 }; 219 220 static int __init s390_cma_mem_init(void) 221 { 222 return register_memory_notifier(&s390_cma_mem_nb); 223 } 224 device_initcall(s390_cma_mem_init); 225 226 #endif /* CONFIG_CMA */ 227 228 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, 229 bool want_memblock) 230 { 231 unsigned long start_pfn = PFN_DOWN(start); 232 unsigned long size_pages = PFN_DOWN(size); 233 int rc; 234 235 rc = vmem_add_mapping(start, size); 236 if (rc) 237 return rc; 238 239 rc = __add_pages(nid, start_pfn, size_pages, altmap, want_memblock); 240 if (rc) 241 vmem_remove_mapping(start, size); 242 return rc; 243 } 244 245 #ifdef CONFIG_MEMORY_HOTREMOVE 246 int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) 247 { 248 /* 249 * There is no hardware or firmware interface which could trigger a 250 * hot memory remove on s390. So there is nothing that needs to be 251 * implemented. 252 */ 253 return -EBUSY; 254 } 255 #endif 256 #endif /* CONFIG_MEMORY_HOTPLUG */ 257