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 <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 static pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
  53
  54 unsigned long s390_invalid_asce;
  55
  56 unsigned long empty_zero_page, zero_page_mask;
  57 EXPORT_SYMBOL(empty_zero_page);
  58 EXPORT_SYMBOL(zero_page_mask);
  59
  60 bool initmem_freed;
  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 #ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
 173
 174 int arch_has_restricted_virtio_memory_access(void)
 175 {
 176         return is_prot_virt_guest();
 177 }
 178 EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
 179
 180 #endif
 181
 182 /* protected virtualization */
 183 static void pv_init(void)
 184 {
 185         if (!is_prot_virt_guest())
 186                 return;
 187
 188         /* make sure bounce buffers are shared */
 189         swiotlb_init(1);
 190         swiotlb_update_mem_attributes();
 191         swiotlb_force = SWIOTLB_FORCE;
 192 }
 193
 194 void __init mem_init(void)
 195 {
 196         cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
 197         cpumask_set_cpu(0, mm_cpumask(&init_mm));
 198
 199         set_max_mapnr(max_low_pfn);
 200         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 201
 202         pv_init();
 203
 204         /* Setup guest page hinting */
 205         cmma_init();
 206
 207         /* this will put all low memory onto the freelists */
 208         memblock_free_all();
 209         setup_zero_pages();     /* Setup zeroed pages. */
 210
 211         cmma_init_nodat();
 212
 213         mem_init_print_info(NULL);
 214 }
 215
 216 void free_initmem(void)
 217 {
 218         initmem_freed = true;
 219         __set_memory((unsigned long)_sinittext,
 220                      (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
 221                      SET_MEMORY_RW | SET_MEMORY_NX);
 222         free_initmem_default(POISON_FREE_INITMEM);
 223 }
 224
 225 unsigned long memory_block_size_bytes(void)
 226 {
 227         /*
 228          * Make sure the memory block size is always greater
 229          * or equal than the memory increment size.
 230          */
 231         return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
 232 }
 233
 234 #ifdef CONFIG_MEMORY_HOTPLUG
 235
 236 #ifdef CONFIG_CMA
 237
 238 /* Prevent memory blocks which contain cma regions from going offline */
 239
 240 struct s390_cma_mem_data {
 241         unsigned long start;
 242         unsigned long end;
 243 };
 244
 245 static int s390_cma_check_range(struct cma *cma, void *data)
 246 {
 247         struct s390_cma_mem_data *mem_data;
 248         unsigned long start, end;
 249
 250         mem_data = data;
 251         start = cma_get_base(cma);
 252         end = start + cma_get_size(cma);
 253         if (end < mem_data->start)
 254                 return 0;
 255         if (start >= mem_data->end)
 256                 return 0;
 257         return -EBUSY;
 258 }
 259
 260 static int s390_cma_mem_notifier(struct notifier_block *nb,
 261                                  unsigned long action, void *data)
 262 {
 263         struct s390_cma_mem_data mem_data;
 264         struct memory_notify *arg;
 265         int rc = 0;
 266
 267         arg = data;
 268         mem_data.start = arg->start_pfn << PAGE_SHIFT;
 269         mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
 270         if (action == MEM_GOING_OFFLINE)
 271                 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
 272         return notifier_from_errno(rc);
 273 }
 274
 275 static struct notifier_block s390_cma_mem_nb = {
 276         .notifier_call = s390_cma_mem_notifier,
 277 };
 278
 279 static int __init s390_cma_mem_init(void)
 280 {
 281         return register_memory_notifier(&s390_cma_mem_nb);
 282 }
 283 device_initcall(s390_cma_mem_init);
 284
 285 #endif /* CONFIG_CMA */
 286
 287 int arch_add_memory(int nid, u64 start, u64 size,
 288                     struct mhp_params *params)
 289 {
 290         unsigned long start_pfn = PFN_DOWN(start);
 291         unsigned long size_pages = PFN_DOWN(size);
 292         int rc;
 293
 294         if (WARN_ON_ONCE(params->altmap))
 295                 return -EINVAL;
 296
 297         if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
 298                 return -EINVAL;
 299
 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(int nid, u64 start, u64 size,
 311                         struct vmem_altmap *altmap)
 312 {
 313         unsigned long start_pfn = start >> PAGE_SHIFT;
 314         unsigned long nr_pages = size >> PAGE_SHIFT;
 315
 316         __remove_pages(start_pfn, nr_pages, altmap);
 317         vmem_remove_mapping(start, size);
 318 }
 319 #endif /* CONFIG_MEMORY_HOTPLUG */