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 <linux/platform-feature.h> 35 #include <asm/processor.h> 36 #include <linux/uaccess.h> 37 #include <asm/pgalloc.h> 38 #include <asm/kfence.h> 39 #include <asm/ptdump.h> 40 #include <asm/dma.h> 41 #include <asm/lowcore.h> 42 #include <asm/tlb.h> 43 #include <asm/tlbflush.h> 44 #include <asm/sections.h> 45 #include <asm/ctl_reg.h> 46 #include <asm/sclp.h> 47 #include <asm/set_memory.h> 48 #include <asm/kasan.h> 49 #include <asm/dma-mapping.h> 50 #include <asm/uv.h> 51 #include <linux/virtio_config.h> 52 53 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir"); 54 static pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir"); 55 56 unsigned long s390_invalid_asce; 57 58 unsigned long empty_zero_page, zero_page_mask; 59 EXPORT_SYMBOL(empty_zero_page); 60 EXPORT_SYMBOL(zero_page_mask); 61 62 static void __init setup_zero_pages(void) 63 { 64 unsigned int order; 65 struct page *page; 66 int i; 67 68 /* Latest machines require a mapping granularity of 512KB */ 69 order = 7; 70 71 /* Limit number of empty zero pages for small memory sizes */ 72 while (order > 2 && (totalram_pages() >> 10) < (1UL << order)) 73 order--; 74 75 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); 76 if (!empty_zero_page) 77 panic("Out of memory in setup_zero_pages"); 78 79 page = virt_to_page((void *) empty_zero_page); 80 split_page(page, order); 81 for (i = 1 << order; i > 0; i--) { 82 mark_page_reserved(page); 83 page++; 84 } 85 86 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; 87 } 88 89 /* 90 * paging_init() sets up the page tables 91 */ 92 void __init paging_init(void) 93 { 94 unsigned long max_zone_pfns[MAX_NR_ZONES]; 95 unsigned long pgd_type, asce_bits; 96 psw_t psw; 97 98 s390_invalid_asce = (unsigned long)invalid_pg_dir; 99 s390_invalid_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 100 crst_table_init((unsigned long *)invalid_pg_dir, _REGION3_ENTRY_EMPTY); 101 init_mm.pgd = swapper_pg_dir; 102 if (VMALLOC_END > _REGION2_SIZE) { 103 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; 104 pgd_type = _REGION2_ENTRY_EMPTY; 105 } else { 106 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 107 pgd_type = _REGION3_ENTRY_EMPTY; 108 } 109 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits; 110 S390_lowcore.kernel_asce = init_mm.context.asce; 111 S390_lowcore.user_asce = s390_invalid_asce; 112 crst_table_init((unsigned long *) init_mm.pgd, pgd_type); 113 vmem_map_init(); 114 kasan_copy_shadow_mapping(); 115 116 /* enable virtual mapping in kernel mode */ 117 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 118 __ctl_load(S390_lowcore.user_asce, 7, 7); 119 __ctl_load(S390_lowcore.kernel_asce, 13, 13); 120 psw.mask = __extract_psw(); 121 psw_bits(psw).dat = 1; 122 psw_bits(psw).as = PSW_BITS_AS_HOME; 123 __load_psw_mask(psw.mask); 124 kasan_free_early_identity(); 125 126 sparse_init(); 127 zone_dma_bits = 31; 128 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 129 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); 130 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 131 free_area_init(max_zone_pfns); 132 } 133 134 void mark_rodata_ro(void) 135 { 136 unsigned long size = __end_ro_after_init - __start_ro_after_init; 137 138 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT); 139 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); 140 debug_checkwx(); 141 } 142 143 int set_memory_encrypted(unsigned long addr, int numpages) 144 { 145 int i; 146 147 /* make specified pages unshared, (swiotlb, dma_free) */ 148 for (i = 0; i < numpages; ++i) { 149 uv_remove_shared(addr); 150 addr += PAGE_SIZE; 151 } 152 return 0; 153 } 154 155 int set_memory_decrypted(unsigned long addr, int numpages) 156 { 157 int i; 158 /* make specified pages shared (swiotlb, dma_alloca) */ 159 for (i = 0; i < numpages; ++i) { 160 uv_set_shared(addr); 161 addr += PAGE_SIZE; 162 } 163 return 0; 164 } 165 166 /* are we a protected virtualization guest? */ 167 bool force_dma_unencrypted(struct device *dev) 168 { 169 return is_prot_virt_guest(); 170 } 171 172 /* protected virtualization */ 173 static void pv_init(void) 174 { 175 if (!is_prot_virt_guest()) 176 return; 177 178 platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS); 179 180 /* make sure bounce buffers are shared */ 181 swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE); 182 swiotlb_update_mem_attributes(); 183 } 184 185 void __init mem_init(void) 186 { 187 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); 188 cpumask_set_cpu(0, mm_cpumask(&init_mm)); 189 190 set_max_mapnr(max_low_pfn); 191 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 192 193 pv_init(); 194 kfence_split_mapping(); 195 /* Setup guest page hinting */ 196 cmma_init(); 197 198 /* this will put all low memory onto the freelists */ 199 memblock_free_all(); 200 setup_zero_pages(); /* Setup zeroed pages. */ 201 202 cmma_init_nodat(); 203 } 204 205 void free_initmem(void) 206 { 207 __set_memory((unsigned long)_sinittext, 208 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT, 209 SET_MEMORY_RW | SET_MEMORY_NX); 210 free_reserved_area(sclp_early_sccb, 211 sclp_early_sccb + EXT_SCCB_READ_SCP, 212 POISON_FREE_INITMEM, "unused early sccb"); 213 free_initmem_default(POISON_FREE_INITMEM); 214 } 215 216 unsigned long memory_block_size_bytes(void) 217 { 218 /* 219 * Make sure the memory block size is always greater 220 * or equal than the memory increment size. 221 */ 222 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm); 223 } 224 225 #ifdef CONFIG_MEMORY_HOTPLUG 226 227 #ifdef CONFIG_CMA 228 229 /* Prevent memory blocks which contain cma regions from going offline */ 230 231 struct s390_cma_mem_data { 232 unsigned long start; 233 unsigned long end; 234 }; 235 236 static int s390_cma_check_range(struct cma *cma, void *data) 237 { 238 struct s390_cma_mem_data *mem_data; 239 unsigned long start, end; 240 241 mem_data = data; 242 start = cma_get_base(cma); 243 end = start + cma_get_size(cma); 244 if (end < mem_data->start) 245 return 0; 246 if (start >= mem_data->end) 247 return 0; 248 return -EBUSY; 249 } 250 251 static int s390_cma_mem_notifier(struct notifier_block *nb, 252 unsigned long action, void *data) 253 { 254 struct s390_cma_mem_data mem_data; 255 struct memory_notify *arg; 256 int rc = 0; 257 258 arg = data; 259 mem_data.start = arg->start_pfn << PAGE_SHIFT; 260 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT); 261 if (action == MEM_GOING_OFFLINE) 262 rc = cma_for_each_area(s390_cma_check_range, &mem_data); 263 return notifier_from_errno(rc); 264 } 265 266 static struct notifier_block s390_cma_mem_nb = { 267 .notifier_call = s390_cma_mem_notifier, 268 }; 269 270 static int __init s390_cma_mem_init(void) 271 { 272 return register_memory_notifier(&s390_cma_mem_nb); 273 } 274 device_initcall(s390_cma_mem_init); 275 276 #endif /* CONFIG_CMA */ 277 278 int arch_add_memory(int nid, u64 start, u64 size, 279 struct mhp_params *params) 280 { 281 unsigned long start_pfn = PFN_DOWN(start); 282 unsigned long size_pages = PFN_DOWN(size); 283 int rc; 284 285 if (WARN_ON_ONCE(params->altmap)) 286 return -EINVAL; 287 288 if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) 289 return -EINVAL; 290 291 VM_BUG_ON(!mhp_range_allowed(start, size, true)); 292 rc = vmem_add_mapping(start, size); 293 if (rc) 294 return rc; 295 296 rc = __add_pages(nid, start_pfn, size_pages, params); 297 if (rc) 298 vmem_remove_mapping(start, size); 299 return rc; 300 } 301 302 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) 303 { 304 unsigned long start_pfn = start >> PAGE_SHIFT; 305 unsigned long nr_pages = size >> PAGE_SHIFT; 306 307 __remove_pages(start_pfn, nr_pages, altmap); 308 vmem_remove_mapping(start, size); 309 } 310 #endif /* CONFIG_MEMORY_HOTPLUG */ 311