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