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/swiotlb.h> 22 #include <linux/smp.h> 23 #include <linux/init.h> 24 #include <linux/pagemap.h> 25 #include <linux/memblock.h> 26 #include <linux/memory.h> 27 #include <linux/pfn.h> 28 #include <linux/poison.h> 29 #include <linux/initrd.h> 30 #include <linux/export.h> 31 #include <linux/cma.h> 32 #include <linux/gfp.h> 33 #include <linux/dma-direct.h> 34 #include <asm/processor.h> 35 #include <linux/uaccess.h> 36 #include <asm/pgalloc.h> 37 #include <asm/ptdump.h> 38 #include <asm/dma.h> 39 #include <asm/lowcore.h> 40 #include <asm/tlb.h> 41 #include <asm/tlbflush.h> 42 #include <asm/sections.h> 43 #include <asm/ctl_reg.h> 44 #include <asm/sclp.h> 45 #include <asm/set_memory.h> 46 #include <asm/kasan.h> 47 #include <asm/dma-mapping.h> 48 #include <asm/uv.h> 49 #include <linux/virtio_config.h> 50 51 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir"); 52 53 unsigned long empty_zero_page, zero_page_mask; 54 EXPORT_SYMBOL(empty_zero_page); 55 EXPORT_SYMBOL(zero_page_mask); 56 57 bool initmem_freed; 58 59 static void __init setup_zero_pages(void) 60 { 61 unsigned int order; 62 struct page *page; 63 int i; 64 65 /* Latest machines require a mapping granularity of 512KB */ 66 order = 7; 67 68 /* Limit number of empty zero pages for small memory sizes */ 69 while (order > 2 && (totalram_pages() >> 10) < (1UL << order)) 70 order--; 71 72 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); 73 if (!empty_zero_page) 74 panic("Out of memory in setup_zero_pages"); 75 76 page = virt_to_page((void *) empty_zero_page); 77 split_page(page, order); 78 for (i = 1 << order; i > 0; i--) { 79 mark_page_reserved(page); 80 page++; 81 } 82 83 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; 84 } 85 86 /* 87 * paging_init() sets up the page tables 88 */ 89 void __init paging_init(void) 90 { 91 unsigned long max_zone_pfns[MAX_NR_ZONES]; 92 unsigned long pgd_type, asce_bits; 93 psw_t psw; 94 95 init_mm.pgd = swapper_pg_dir; 96 if (VMALLOC_END > _REGION2_SIZE) { 97 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; 98 pgd_type = _REGION2_ENTRY_EMPTY; 99 } else { 100 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 101 pgd_type = _REGION3_ENTRY_EMPTY; 102 } 103 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits; 104 S390_lowcore.kernel_asce = init_mm.context.asce; 105 S390_lowcore.user_asce = S390_lowcore.kernel_asce; 106 crst_table_init((unsigned long *) init_mm.pgd, pgd_type); 107 vmem_map_init(); 108 kasan_copy_shadow(init_mm.pgd); 109 110 /* enable virtual mapping in kernel mode */ 111 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 112 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 113 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 114 psw.mask = __extract_psw(); 115 psw_bits(psw).dat = 1; 116 psw_bits(psw).as = PSW_BITS_AS_HOME; 117 __load_psw_mask(psw.mask); 118 kasan_free_early_identity(); 119 120 sparse_init(); 121 zone_dma_bits = 31; 122 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 123 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 124 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 125 free_area_init(max_zone_pfns); 126 } 127 128 void mark_rodata_ro(void) 129 { 130 unsigned long size = __end_ro_after_init - __start_ro_after_init; 131 132 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT); 133 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); 134 debug_checkwx(); 135 } 136 137 int set_memory_encrypted(unsigned long addr, int numpages) 138 { 139 int i; 140 141 /* make specified pages unshared, (swiotlb, dma_free) */ 142 for (i = 0; i < numpages; ++i) { 143 uv_remove_shared(addr); 144 addr += PAGE_SIZE; 145 } 146 return 0; 147 } 148 149 int set_memory_decrypted(unsigned long addr, int numpages) 150 { 151 int i; 152 /* make specified pages shared (swiotlb, dma_alloca) */ 153 for (i = 0; i < numpages; ++i) { 154 uv_set_shared(addr); 155 addr += PAGE_SIZE; 156 } 157 return 0; 158 } 159 160 /* are we a protected virtualization guest? */ 161 bool force_dma_unencrypted(struct device *dev) 162 { 163 return is_prot_virt_guest(); 164 } 165 166 #ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 167 168 int arch_has_restricted_virtio_memory_access(void) 169 { 170 return is_prot_virt_guest(); 171 } 172 EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access); 173 174 #endif 175 176 /* protected virtualization */ 177 static void pv_init(void) 178 { 179 if (!is_prot_virt_guest()) 180 return; 181 182 /* make sure bounce buffers are shared */ 183 swiotlb_init(1); 184 swiotlb_update_mem_attributes(); 185 swiotlb_force = SWIOTLB_FORCE; 186 } 187 188 void __init mem_init(void) 189 { 190 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); 191 cpumask_set_cpu(0, mm_cpumask(&init_mm)); 192 193 set_max_mapnr(max_low_pfn); 194 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 195 196 pv_init(); 197 198 /* Setup guest page hinting */ 199 cmma_init(); 200 201 /* this will put all low memory onto the freelists */ 202 memblock_free_all(); 203 setup_zero_pages(); /* Setup zeroed pages. */ 204 205 cmma_init_nodat(); 206 207 mem_init_print_info(NULL); 208 } 209 210 void free_initmem(void) 211 { 212 initmem_freed = true; 213 __set_memory((unsigned long)_sinittext, 214 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT, 215 SET_MEMORY_RW | SET_MEMORY_NX); 216 free_initmem_default(POISON_FREE_INITMEM); 217 } 218 219 unsigned long memory_block_size_bytes(void) 220 { 221 /* 222 * Make sure the memory block size is always greater 223 * or equal than the memory increment size. 224 */ 225 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm); 226 } 227 228 #ifdef CONFIG_MEMORY_HOTPLUG 229 230 #ifdef CONFIG_CMA 231 232 /* Prevent memory blocks which contain cma regions from going offline */ 233 234 struct s390_cma_mem_data { 235 unsigned long start; 236 unsigned long end; 237 }; 238 239 static int s390_cma_check_range(struct cma *cma, void *data) 240 { 241 struct s390_cma_mem_data *mem_data; 242 unsigned long start, end; 243 244 mem_data = data; 245 start = cma_get_base(cma); 246 end = start + cma_get_size(cma); 247 if (end < mem_data->start) 248 return 0; 249 if (start >= mem_data->end) 250 return 0; 251 return -EBUSY; 252 } 253 254 static int s390_cma_mem_notifier(struct notifier_block *nb, 255 unsigned long action, void *data) 256 { 257 struct s390_cma_mem_data mem_data; 258 struct memory_notify *arg; 259 int rc = 0; 260 261 arg = data; 262 mem_data.start = arg->start_pfn << PAGE_SHIFT; 263 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT); 264 if (action == MEM_GOING_OFFLINE) 265 rc = cma_for_each_area(s390_cma_check_range, &mem_data); 266 return notifier_from_errno(rc); 267 } 268 269 static struct notifier_block s390_cma_mem_nb = { 270 .notifier_call = s390_cma_mem_notifier, 271 }; 272 273 static int __init s390_cma_mem_init(void) 274 { 275 return register_memory_notifier(&s390_cma_mem_nb); 276 } 277 device_initcall(s390_cma_mem_init); 278 279 #endif /* CONFIG_CMA */ 280 281 int arch_add_memory(int nid, u64 start, u64 size, 282 struct mhp_params *params) 283 { 284 unsigned long start_pfn = PFN_DOWN(start); 285 unsigned long size_pages = PFN_DOWN(size); 286 int rc; 287 288 if (WARN_ON_ONCE(params->altmap)) 289 return -EINVAL; 290 291 if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) 292 return -EINVAL; 293 294 rc = vmem_add_mapping(start, size); 295 if (rc) 296 return rc; 297 298 rc = __add_pages(nid, start_pfn, size_pages, params); 299 if (rc) 300 vmem_remove_mapping(start, size); 301 return rc; 302 } 303 304 void arch_remove_memory(int nid, u64 start, u64 size, 305 struct vmem_altmap *altmap) 306 { 307 unsigned long start_pfn = start >> PAGE_SHIFT; 308 unsigned long nr_pages = size >> PAGE_SHIFT; 309 310 __remove_pages(start_pfn, nr_pages, altmap); 311 vmem_remove_mapping(start, size); 312 } 313 #endif /* CONFIG_MEMORY_HOTPLUG */ 314