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