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/kfence.h> 38 #include <asm/ptdump.h> 39 #include <asm/dma.h> 40 #include <asm/lowcore.h> 41 #include <asm/tlb.h> 42 #include <asm/tlbflush.h> 43 #include <asm/sections.h> 44 #include <asm/ctl_reg.h> 45 #include <asm/sclp.h> 46 #include <asm/set_memory.h> 47 #include <asm/kasan.h> 48 #include <asm/dma-mapping.h> 49 #include <asm/uv.h> 50 #include <linux/virtio_config.h> 51 52 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir"); 53 static pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir"); 54 55 unsigned long s390_invalid_asce; 56 57 unsigned long empty_zero_page, zero_page_mask; 58 EXPORT_SYMBOL(empty_zero_page); 59 EXPORT_SYMBOL(zero_page_mask); 60 61 static void __init setup_zero_pages(void) 62 { 63 unsigned int order; 64 struct page *page; 65 int i; 66 67 /* Latest machines require a mapping granularity of 512KB */ 68 order = 7; 69 70 /* Limit number of empty zero pages for small memory sizes */ 71 while (order > 2 && (totalram_pages() >> 10) < (1UL << order)) 72 order--; 73 74 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); 75 if (!empty_zero_page) 76 panic("Out of memory in setup_zero_pages"); 77 78 page = virt_to_page((void *) empty_zero_page); 79 split_page(page, order); 80 for (i = 1 << order; i > 0; i--) { 81 mark_page_reserved(page); 82 page++; 83 } 84 85 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; 86 } 87 88 /* 89 * paging_init() sets up the page tables 90 */ 91 void __init paging_init(void) 92 { 93 unsigned long max_zone_pfns[MAX_NR_ZONES]; 94 unsigned long pgd_type, asce_bits; 95 psw_t psw; 96 97 s390_invalid_asce = (unsigned long)invalid_pg_dir; 98 s390_invalid_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 99 crst_table_init((unsigned long *)invalid_pg_dir, _REGION3_ENTRY_EMPTY); 100 init_mm.pgd = swapper_pg_dir; 101 if (VMALLOC_END > _REGION2_SIZE) { 102 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; 103 pgd_type = _REGION2_ENTRY_EMPTY; 104 } else { 105 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 106 pgd_type = _REGION3_ENTRY_EMPTY; 107 } 108 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits; 109 S390_lowcore.kernel_asce = init_mm.context.asce; 110 S390_lowcore.user_asce = s390_invalid_asce; 111 crst_table_init((unsigned long *) init_mm.pgd, pgd_type); 112 vmem_map_init(); 113 kasan_copy_shadow_mapping(); 114 115 /* enable virtual mapping in kernel mode */ 116 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 117 __ctl_load(S390_lowcore.user_asce, 7, 7); 118 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 119 psw.mask = __extract_psw(); 120 psw_bits(psw).dat = 1; 121 psw_bits(psw).as = PSW_BITS_AS_HOME; 122 __load_psw_mask(psw.mask); 123 kasan_free_early_identity(); 124 125 sparse_init(); 126 zone_dma_bits = 31; 127 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 128 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 129 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 130 free_area_init(max_zone_pfns); 131 } 132 133 void mark_rodata_ro(void) 134 { 135 unsigned long size = __end_ro_after_init - __start_ro_after_init; 136 137 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT); 138 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); 139 debug_checkwx(); 140 } 141 142 int set_memory_encrypted(unsigned long addr, int numpages) 143 { 144 int i; 145 146 /* make specified pages unshared, (swiotlb, dma_free) */ 147 for (i = 0; i < numpages; ++i) { 148 uv_remove_shared(addr); 149 addr += PAGE_SIZE; 150 } 151 return 0; 152 } 153 154 int set_memory_decrypted(unsigned long addr, int numpages) 155 { 156 int i; 157 /* make specified pages shared (swiotlb, dma_alloca) */ 158 for (i = 0; i < numpages; ++i) { 159 uv_set_shared(addr); 160 addr += PAGE_SIZE; 161 } 162 return 0; 163 } 164 165 /* are we a protected virtualization guest? */ 166 bool force_dma_unencrypted(struct device *dev) 167 { 168 return is_prot_virt_guest(); 169 } 170 171 #ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 172 173 int arch_has_restricted_virtio_memory_access(void) 174 { 175 return is_prot_virt_guest(); 176 } 177 EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access); 178 179 #endif 180 181 /* protected virtualization */ 182 static void pv_init(void) 183 { 184 if (!is_prot_virt_guest()) 185 return; 186 187 /* make sure bounce buffers are shared */ 188 swiotlb_force = SWIOTLB_FORCE; 189 swiotlb_init(1); 190 swiotlb_update_mem_attributes(); 191 } 192 193 void __init mem_init(void) 194 { 195 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); 196 cpumask_set_cpu(0, mm_cpumask(&init_mm)); 197 198 set_max_mapnr(max_low_pfn); 199 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 200 201 pv_init(); 202 kfence_split_mapping(); 203 /* Setup guest page hinting */ 204 cmma_init(); 205 206 /* this will put all low memory onto the freelists */ 207 memblock_free_all(); 208 setup_zero_pages(); /* Setup zeroed pages. */ 209 210 cmma_init_nodat(); 211 } 212 213 void free_initmem(void) 214 { 215 __set_memory((unsigned long)_sinittext, 216 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT, 217 SET_MEMORY_RW | SET_MEMORY_NX); 218 free_reserved_area(sclp_early_sccb, 219 sclp_early_sccb + EXT_SCCB_READ_SCP, 220 POISON_FREE_INITMEM, "unused early sccb"); 221 free_initmem_default(POISON_FREE_INITMEM); 222 } 223 224 unsigned long memory_block_size_bytes(void) 225 { 226 /* 227 * Make sure the memory block size is always greater 228 * or equal than the memory increment size. 229 */ 230 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm); 231 } 232 233 #ifdef CONFIG_MEMORY_HOTPLUG 234 235 #ifdef CONFIG_CMA 236 237 /* Prevent memory blocks which contain cma regions from going offline */ 238 239 struct s390_cma_mem_data { 240 unsigned long start; 241 unsigned long end; 242 }; 243 244 static int s390_cma_check_range(struct cma *cma, void *data) 245 { 246 struct s390_cma_mem_data *mem_data; 247 unsigned long start, end; 248 249 mem_data = data; 250 start = cma_get_base(cma); 251 end = start + cma_get_size(cma); 252 if (end < mem_data->start) 253 return 0; 254 if (start >= mem_data->end) 255 return 0; 256 return -EBUSY; 257 } 258 259 static int s390_cma_mem_notifier(struct notifier_block *nb, 260 unsigned long action, void *data) 261 { 262 struct s390_cma_mem_data mem_data; 263 struct memory_notify *arg; 264 int rc = 0; 265 266 arg = data; 267 mem_data.start = arg->start_pfn << PAGE_SHIFT; 268 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT); 269 if (action == MEM_GOING_OFFLINE) 270 rc = cma_for_each_area(s390_cma_check_range, &mem_data); 271 return notifier_from_errno(rc); 272 } 273 274 static struct notifier_block s390_cma_mem_nb = { 275 .notifier_call = s390_cma_mem_notifier, 276 }; 277 278 static int __init s390_cma_mem_init(void) 279 { 280 return register_memory_notifier(&s390_cma_mem_nb); 281 } 282 device_initcall(s390_cma_mem_init); 283 284 #endif /* CONFIG_CMA */ 285 286 int arch_add_memory(int nid, u64 start, u64 size, 287 struct mhp_params *params) 288 { 289 unsigned long start_pfn = PFN_DOWN(start); 290 unsigned long size_pages = PFN_DOWN(size); 291 int rc; 292 293 if (WARN_ON_ONCE(params->altmap)) 294 return -EINVAL; 295 296 if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) 297 return -EINVAL; 298 299 VM_BUG_ON(!mhp_range_allowed(start, size, true)); 300 rc = vmem_add_mapping(start, size); 301 if (rc) 302 return rc; 303 304 rc = __add_pages(nid, start_pfn, size_pages, params); 305 if (rc) 306 vmem_remove_mapping(start, size); 307 return rc; 308 } 309 310 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) 311 { 312 unsigned long start_pfn = start >> PAGE_SHIFT; 313 unsigned long nr_pages = size >> PAGE_SHIFT; 314 315 __remove_pages(start_pfn, nr_pages, altmap); 316 vmem_remove_mapping(start, size); 317 } 318 #endif /* CONFIG_MEMORY_HOTPLUG */ 319