arch/s390/mm/init.c

   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/percpu.h>
  35 #include <asm/processor.h>
  36 #include <linux/uaccess.h>
  37 #include <asm/pgalloc.h>
  38 #include <asm/ctlreg.h>
  39 #include <asm/kfence.h>
  40 #include <asm/dma.h>
  41 #include <asm/abs_lowcore.h>
  42 #include <asm/tlb.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
  54 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
  55 pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
  56
  57 struct ctlreg __bootdata_preserved(s390_invalid_asce);
  58
  59 unsigned long __bootdata_preserved(page_noexec_mask);
  60 EXPORT_SYMBOL(page_noexec_mask);
  61
  62 unsigned long __bootdata_preserved(segment_noexec_mask);
  63 EXPORT_SYMBOL(segment_noexec_mask);
  64
  65 unsigned long __bootdata_preserved(region_noexec_mask);
  66 EXPORT_SYMBOL(region_noexec_mask);
  67
  68 unsigned long empty_zero_page, zero_page_mask;
  69 EXPORT_SYMBOL(empty_zero_page);
  70 EXPORT_SYMBOL(zero_page_mask);
  71
  72 static void __init setup_zero_pages(void)
  73 {
  74         unsigned long total_pages = memblock_estimated_nr_free_pages();
  75         unsigned int order;
  76         struct page *page;
  77         int i;
  78
  79         /* Latest machines require a mapping granularity of 512KB */
  80         order = 7;
  81
  82         /* Limit number of empty zero pages for small memory sizes */
  83         while (order > 2 && (total_pages >> 10) < (1UL << order))
  84                 order--;
  85
  86         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  87         if (!empty_zero_page)
  88                 panic("Out of memory in setup_zero_pages");
  89
  90         page = virt_to_page((void *) empty_zero_page);
  91         split_page(page, order);
  92         for (i = 1 << order; i > 0; i--) {
  93                 mark_page_reserved(page);
  94                 page++;
  95         }
  96
  97         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  98 }
  99
 100 /*
 101  * paging_init() sets up the page tables
 102  */
 103 void __init paging_init(void)
 104 {
 105         unsigned long max_zone_pfns[MAX_NR_ZONES];
 106
 107         vmem_map_init();
 108         sparse_init();
 109         zone_dma_limit = DMA_BIT_MASK(31);
 110         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 111         max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
 112         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 113         free_area_init(max_zone_pfns);
 114 }
 115
 116 void mark_rodata_ro(void)
 117 {
 118         unsigned long size = __end_ro_after_init - __start_ro_after_init;
 119
 120         if (MACHINE_HAS_NX)
 121                 system_ctl_set_bit(0, CR0_INSTRUCTION_EXEC_PROTECTION_BIT);
 122         __set_memory_ro(__start_ro_after_init, __end_ro_after_init);
 123         pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
 124 }
 125
 126 int set_memory_encrypted(unsigned long vaddr, int numpages)
 127 {
 128         int i;
 129
 130         /* make specified pages unshared, (swiotlb, dma_free) */
 131         for (i = 0; i < numpages; ++i) {
 132                 uv_remove_shared(virt_to_phys((void *)vaddr));
 133                 vaddr += PAGE_SIZE;
 134         }
 135         return 0;
 136 }
 137
 138 int set_memory_decrypted(unsigned long vaddr, int numpages)
 139 {
 140         int i;
 141         /* make specified pages shared (swiotlb, dma_alloca) */
 142         for (i = 0; i < numpages; ++i) {
 143                 uv_set_shared(virt_to_phys((void *)vaddr));
 144                 vaddr += PAGE_SIZE;
 145         }
 146         return 0;
 147 }
 148
 149 /* are we a protected virtualization guest? */
 150 bool force_dma_unencrypted(struct device *dev)
 151 {
 152         return is_prot_virt_guest();
 153 }
 154
 155 /* protected virtualization */
 156 static void pv_init(void)
 157 {
 158         if (!is_prot_virt_guest())
 159                 return;
 160
 161         virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
 162
 163         /* make sure bounce buffers are shared */
 164         swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
 165         swiotlb_update_mem_attributes();
 166 }
 167
 168 void __init mem_init(void)
 169 {
 170         cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
 171         cpumask_set_cpu(0, mm_cpumask(&init_mm));
 172
 173         set_max_mapnr(max_low_pfn);
 174         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 175
 176         pv_init();
 177         kfence_split_mapping();
 178
 179         /* this will put all low memory onto the freelists */
 180         memblock_free_all();
 181         setup_zero_pages();     /* Setup zeroed pages. */
 182 }
 183
 184 unsigned long memory_block_size_bytes(void)
 185 {
 186         /*
 187          * Make sure the memory block size is always greater
 188          * or equal than the memory increment size.
 189          */
 190         return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
 191 }
 192
 193 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
 194 EXPORT_SYMBOL(__per_cpu_offset);
 195
 196 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
 197 {
 198         return LOCAL_DISTANCE;
 199 }
 200
 201 static int __init pcpu_cpu_to_node(int cpu)
 202 {
 203         return 0;
 204 }
 205
 206 void __init setup_per_cpu_areas(void)
 207 {
 208         unsigned long delta;
 209         unsigned int cpu;
 210         int rc;
 211
 212         /*
 213          * Always reserve area for module percpu variables.  That's
 214          * what the legacy allocator did.
 215          */
 216         rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
 217                                     PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
 218                                     pcpu_cpu_distance,
 219                                     pcpu_cpu_to_node);
 220         if (rc < 0)
 221                 panic("Failed to initialize percpu areas.");
 222
 223         delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
 224         for_each_possible_cpu(cpu)
 225                 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
 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->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
 312 #ifdef CONFIG_EXECMEM
 313 static struct execmem_info execmem_info __ro_after_init;
 314
 315 struct execmem_info __init *execmem_arch_setup(void)
 316 {
 317         unsigned long module_load_offset = 0;
 318         unsigned long start;
 319
 320         if (kaslr_enabled())
 321                 module_load_offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
 322
 323         start = MODULES_VADDR + module_load_offset;
 324
 325         execmem_info = (struct execmem_info){
 326                 .ranges = {
 327                         [EXECMEM_DEFAULT] = {
 328                                 .flags  = EXECMEM_KASAN_SHADOW,
 329                                 .start  = start,
 330                                 .end    = MODULES_END,
 331                                 .pgprot = PAGE_KERNEL,
 332                                 .alignment = MODULE_ALIGN,
 333                         },
 334                 },
 335         };
 336
 337         return &execmem_info;
 338 }
 339 #endif /* CONFIG_EXECMEM */