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/cpufeature.h> 12 #include <linux/signal.h> 13 #include <linux/sched.h> 14 #include <linux/kernel.h> 15 #include <linux/errno.h> 16 #include <linux/string.h> 17 #include <linux/types.h> 18 #include <linux/ptrace.h> 19 #include <linux/mman.h> 20 #include <linux/mm.h> 21 #include <linux/swap.h> 22 #include <linux/swiotlb.h> 23 #include <linux/smp.h> 24 #include <linux/init.h> 25 #include <linux/pagemap.h> 26 #include <linux/memblock.h> 27 #include <linux/memory.h> 28 #include <linux/pfn.h> 29 #include <linux/poison.h> 30 #include <linux/initrd.h> 31 #include <linux/export.h> 32 #include <linux/cma.h> 33 #include <linux/gfp.h> 34 #include <linux/dma-direct.h> 35 #include <linux/percpu.h> 36 #include <asm/processor.h> 37 #include <linux/uaccess.h> 38 #include <asm/pgalloc.h> 39 #include <asm/ctlreg.h> 40 #include <asm/kfence.h> 41 #include <asm/dma.h> 42 #include <asm/abs_lowcore.h> 43 #include <asm/tlbflush.h> 44 #include <asm/sections.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_anchor.h> 51 #include <linux/virtio_config.h> 52 #include <linux/execmem.h> 53 #include <linux/cc_platform.h> 54 55 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir"); 56 pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir"); 57 58 struct ctlreg __bootdata_preserved(s390_invalid_asce); 59 60 unsigned long __bootdata_preserved(page_noexec_mask); 61 EXPORT_SYMBOL(page_noexec_mask); 62 63 unsigned long __bootdata_preserved(segment_noexec_mask); 64 EXPORT_SYMBOL(segment_noexec_mask); 65 66 unsigned long __bootdata_preserved(region_noexec_mask); 67 EXPORT_SYMBOL(region_noexec_mask); 68 69 unsigned long empty_zero_page, zero_page_mask; 70 EXPORT_SYMBOL(empty_zero_page); 71 EXPORT_SYMBOL(zero_page_mask); 72 73 void __init arch_setup_zero_pages(void) 74 { 75 unsigned long total_pages = memblock_estimated_nr_free_pages(); 76 unsigned int order; 77 78 /* Latest machines require a mapping granularity of 512KB */ 79 order = 7; 80 81 /* Limit number of empty zero pages for small memory sizes */ 82 while (order > 2 && (total_pages >> 10) < (1UL << order)) 83 order--; 84 85 empty_zero_page = (unsigned long)memblock_alloc_or_panic(PAGE_SIZE << order, PAGE_SIZE); 86 87 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK; 88 89 set_memory_ro(empty_zero_page, 1UL << order); 90 } 91 92 void __init arch_zone_limits_init(unsigned long *max_zone_pfns) 93 { 94 max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS); 95 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 96 } 97 98 /* 99 * paging_init() sets up the page tables 100 */ 101 void __init paging_init(void) 102 { 103 vmem_map_init(); 104 zone_dma_limit = DMA_BIT_MASK(31); 105 } 106 107 void mark_rodata_ro(void) 108 { 109 unsigned long size = __end_ro_after_init - __start_ro_after_init; 110 111 if (cpu_has_nx()) 112 system_ctl_set_bit(0, CR0_INSTRUCTION_EXEC_PROTECTION_BIT); 113 __set_memory_ro(__start_ro_after_init, __end_ro_after_init); 114 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); 115 } 116 117 int set_memory_encrypted(unsigned long vaddr, int numpages) 118 { 119 int i; 120 121 /* make specified pages unshared, (swiotlb, dma_free) */ 122 for (i = 0; i < numpages; ++i) { 123 uv_remove_shared(virt_to_phys((void *)vaddr)); 124 vaddr += PAGE_SIZE; 125 } 126 return 0; 127 } 128 129 int set_memory_decrypted(unsigned long vaddr, int numpages) 130 { 131 int i; 132 /* make specified pages shared (swiotlb, dma_alloca) */ 133 for (i = 0; i < numpages; ++i) { 134 uv_set_shared(virt_to_phys((void *)vaddr)); 135 vaddr += PAGE_SIZE; 136 } 137 return 0; 138 } 139 140 /* are we a protected virtualization guest? */ 141 bool force_dma_unencrypted(struct device *dev) 142 { 143 return is_prot_virt_guest(); 144 } 145 146 147 bool cc_platform_has(enum cc_attr attr) 148 { 149 switch (attr) { 150 case CC_ATTR_MEM_ENCRYPT: 151 case CC_ATTR_GUEST_MEM_ENCRYPT: 152 return is_prot_virt_guest(); 153 154 default: 155 return false; 156 } 157 } 158 EXPORT_SYMBOL_GPL(cc_platform_has); 159 160 /* protected virtualization */ 161 static void __init pv_init(void) 162 { 163 if (!is_prot_virt_guest()) 164 return; 165 166 virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc); 167 168 /* make sure bounce buffers are shared */ 169 swiotlb_init(true, SWIOTLB_VERBOSE | SWIOTLB_ANY); 170 swiotlb_update_mem_attributes(); 171 } 172 173 void __init arch_mm_preinit(void) 174 { 175 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); 176 cpumask_set_cpu(0, mm_cpumask(&init_mm)); 177 178 pv_init(); 179 } 180 181 unsigned long memory_block_size_bytes(void) 182 { 183 /* 184 * Make sure the memory block size is always greater 185 * or equal than the memory increment size. 186 */ 187 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm); 188 } 189 190 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; 191 EXPORT_SYMBOL(__per_cpu_offset); 192 193 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to) 194 { 195 return LOCAL_DISTANCE; 196 } 197 198 static int __init pcpu_cpu_to_node(int cpu) 199 { 200 return 0; 201 } 202 203 void __init setup_per_cpu_areas(void) 204 { 205 unsigned long delta; 206 unsigned int cpu; 207 int rc; 208 209 /* 210 * Always reserve area for module percpu variables. That's 211 * what the legacy allocator did. 212 */ 213 rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, 214 PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, 215 pcpu_cpu_distance, 216 pcpu_cpu_to_node); 217 if (rc < 0) 218 panic("Failed to initialize percpu areas."); 219 220 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; 221 for_each_possible_cpu(cpu) 222 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; 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; 239 240 mem_data = data; 241 242 if (cma_intersects(cma, mem_data->start, mem_data->end)) 243 return -EBUSY; 244 245 return 0; 246 } 247 248 static int s390_cma_mem_notifier(struct notifier_block *nb, 249 unsigned long action, void *data) 250 { 251 struct s390_cma_mem_data mem_data; 252 struct memory_notify *arg; 253 int rc = 0; 254 255 arg = data; 256 mem_data.start = arg->start_pfn << PAGE_SHIFT; 257 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT); 258 if (action == MEM_GOING_OFFLINE) 259 rc = cma_for_each_area(s390_cma_check_range, &mem_data); 260 return notifier_from_errno(rc); 261 } 262 263 static struct notifier_block s390_cma_mem_nb = { 264 .notifier_call = s390_cma_mem_notifier, 265 }; 266 267 static int __init s390_cma_mem_init(void) 268 { 269 return register_memory_notifier(&s390_cma_mem_nb); 270 } 271 device_initcall(s390_cma_mem_init); 272 273 #endif /* CONFIG_CMA */ 274 275 int arch_add_memory(int nid, u64 start, u64 size, 276 struct mhp_params *params) 277 { 278 unsigned long start_pfn = PFN_DOWN(start); 279 unsigned long size_pages = PFN_DOWN(size); 280 int rc; 281 282 if (WARN_ON_ONCE(pgprot_val(params->pgprot) != pgprot_val(PAGE_KERNEL))) 283 return -EINVAL; 284 285 VM_BUG_ON(!mhp_range_allowed(start, size, true)); 286 rc = vmem_add_mapping(start, size); 287 if (rc) 288 return rc; 289 290 rc = __add_pages(nid, start_pfn, size_pages, params); 291 if (rc) 292 vmem_remove_mapping(start, size); 293 return rc; 294 } 295 296 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, 297 struct dev_pagemap *pgmap) 298 { 299 unsigned long start_pfn = start >> PAGE_SHIFT; 300 unsigned long nr_pages = size >> PAGE_SHIFT; 301 302 __remove_pages(start_pfn, nr_pages, altmap, pgmap); 303 vmem_remove_mapping(start, size); 304 } 305 #endif /* CONFIG_MEMORY_HOTPLUG */ 306 307 #ifdef CONFIG_EXECMEM 308 static struct execmem_info execmem_info __ro_after_init; 309 310 struct execmem_info __init *execmem_arch_setup(void) 311 { 312 unsigned long module_load_offset = 0; 313 unsigned long start; 314 315 if (kaslr_enabled()) 316 module_load_offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE; 317 318 start = MODULES_VADDR + module_load_offset; 319 320 execmem_info = (struct execmem_info){ 321 .ranges = { 322 [EXECMEM_DEFAULT] = { 323 .flags = EXECMEM_KASAN_SHADOW, 324 .start = start, 325 .end = MODULES_END, 326 .pgprot = PAGE_KERNEL, 327 .alignment = MODULE_ALIGN, 328 }, 329 }, 330 }; 331 332 return &execmem_info; 333 } 334 #endif /* CONFIG_EXECMEM */ 335