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 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 crst_table_init((unsigned long *) init_mm.pgd, pgd_type); 99 vmem_map_init(); 100 101 /* enable virtual mapping in kernel mode */ 102 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 103 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 104 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 105 psw.mask = __extract_psw(); 106 psw_bits(psw).dat = 1; 107 psw_bits(psw).as = PSW_BITS_AS_HOME; 108 __load_psw_mask(psw.mask); 109 110 sparse_memory_present_with_active_regions(MAX_NUMNODES); 111 sparse_init(); 112 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 113 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 114 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 115 free_area_init_nodes(max_zone_pfns); 116 } 117 118 void mark_rodata_ro(void) 119 { 120 unsigned long size = __end_ro_after_init - __start_ro_after_init; 121 122 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT); 123 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); 124 } 125 126 void __init mem_init(void) 127 { 128 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); 129 cpumask_set_cpu(0, mm_cpumask(&init_mm)); 130 131 set_max_mapnr(max_low_pfn); 132 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 133 134 /* Setup guest page hinting */ 135 cmma_init(); 136 137 /* this will put all low memory onto the freelists */ 138 free_all_bootmem(); 139 setup_zero_pages(); /* Setup zeroed pages. */ 140 141 cmma_init_nodat(); 142 143 mem_init_print_info(NULL); 144 } 145 146 void free_initmem(void) 147 { 148 __set_memory((unsigned long) _sinittext, 149 (_einittext - _sinittext) >> PAGE_SHIFT, 150 SET_MEMORY_RW | SET_MEMORY_NX); 151 free_initmem_default(POISON_FREE_INITMEM); 152 } 153 154 #ifdef CONFIG_BLK_DEV_INITRD 155 void __init free_initrd_mem(unsigned long start, unsigned long end) 156 { 157 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM, 158 "initrd"); 159 } 160 #endif 161 162 unsigned long memory_block_size_bytes(void) 163 { 164 /* 165 * Make sure the memory block size is always greater 166 * or equal than the memory increment size. 167 */ 168 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm); 169 } 170 171 #ifdef CONFIG_MEMORY_HOTPLUG 172 173 #ifdef CONFIG_CMA 174 175 /* Prevent memory blocks which contain cma regions from going offline */ 176 177 struct s390_cma_mem_data { 178 unsigned long start; 179 unsigned long end; 180 }; 181 182 static int s390_cma_check_range(struct cma *cma, void *data) 183 { 184 struct s390_cma_mem_data *mem_data; 185 unsigned long start, end; 186 187 mem_data = data; 188 start = cma_get_base(cma); 189 end = start + cma_get_size(cma); 190 if (end < mem_data->start) 191 return 0; 192 if (start >= mem_data->end) 193 return 0; 194 return -EBUSY; 195 } 196 197 static int s390_cma_mem_notifier(struct notifier_block *nb, 198 unsigned long action, void *data) 199 { 200 struct s390_cma_mem_data mem_data; 201 struct memory_notify *arg; 202 int rc = 0; 203 204 arg = data; 205 mem_data.start = arg->start_pfn << PAGE_SHIFT; 206 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT); 207 if (action == MEM_GOING_OFFLINE) 208 rc = cma_for_each_area(s390_cma_check_range, &mem_data); 209 return notifier_from_errno(rc); 210 } 211 212 static struct notifier_block s390_cma_mem_nb = { 213 .notifier_call = s390_cma_mem_notifier, 214 }; 215 216 static int __init s390_cma_mem_init(void) 217 { 218 return register_memory_notifier(&s390_cma_mem_nb); 219 } 220 device_initcall(s390_cma_mem_init); 221 222 #endif /* CONFIG_CMA */ 223 224 int arch_add_memory(int nid, u64 start, u64 size, bool want_memblock) 225 { 226 unsigned long start_pfn = PFN_DOWN(start); 227 unsigned long size_pages = PFN_DOWN(size); 228 int rc; 229 230 rc = vmem_add_mapping(start, size); 231 if (rc) 232 return rc; 233 234 rc = __add_pages(nid, start_pfn, size_pages, want_memblock); 235 if (rc) 236 vmem_remove_mapping(start, size); 237 return rc; 238 } 239 240 #ifdef CONFIG_MEMORY_HOTREMOVE 241 int arch_remove_memory(u64 start, u64 size) 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 return -EBUSY; 249 } 250 #endif 251 #endif /* CONFIG_MEMORY_HOTPLUG */ 252