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-mapping.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         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 122         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 123         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 124         free_area_init_nodes(max_zone_pfns);
 125 }
 126
 127 void mark_rodata_ro(void)
 128 {
 129         unsigned long size = __end_ro_after_init - __start_ro_after_init;
 130
 131         set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
 132         pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
 133 }
 134
 135 int set_memory_encrypted(unsigned long addr, int numpages)
 136 {
 137         int i;
 138
 139         /* make specified pages unshared, (swiotlb, dma_free) */
 140         for (i = 0; i < numpages; ++i) {
 141                 uv_remove_shared(addr);
 142                 addr += PAGE_SIZE;
 143         }
 144         return 0;
 145 }
 146
 147 int set_memory_decrypted(unsigned long addr, int numpages)
 148 {
 149         int i;
 150         /* make specified pages shared (swiotlb, dma_alloca) */
 151         for (i = 0; i < numpages; ++i) {
 152                 uv_set_shared(addr);
 153                 addr += PAGE_SIZE;
 154         }
 155         return 0;
 156 }
 157
 158 /* are we a protected virtualization guest? */
 159 bool sev_active(void)
 160 {
 161         return is_prot_virt_guest();
 162 }
 163
 164 /* protected virtualization */
 165 static void pv_init(void)
 166 {
 167         if (!is_prot_virt_guest())
 168                 return;
 169
 170         /* make sure bounce buffers are shared */
 171         swiotlb_init(1);
 172         swiotlb_update_mem_attributes();
 173         swiotlb_force = SWIOTLB_FORCE;
 174 }
 175
 176 void __init mem_init(void)
 177 {
 178         cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
 179         cpumask_set_cpu(0, mm_cpumask(&init_mm));
 180
 181         set_max_mapnr(max_low_pfn);
 182         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 183
 184         pv_init();
 185
 186         /* Setup guest page hinting */
 187         cmma_init();
 188
 189         /* this will put all low memory onto the freelists */
 190         memblock_free_all();
 191         setup_zero_pages();     /* Setup zeroed pages. */
 192
 193         cmma_init_nodat();
 194
 195         mem_init_print_info(NULL);
 196 }
 197
 198 void free_initmem(void)
 199 {
 200         initmem_freed = true;
 201         __set_memory((unsigned long)_sinittext,
 202                      (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
 203                      SET_MEMORY_RW | SET_MEMORY_NX);
 204         free_initmem_default(POISON_FREE_INITMEM);
 205 }
 206
 207 unsigned long memory_block_size_bytes(void)
 208 {
 209         /*
 210          * Make sure the memory block size is always greater
 211          * or equal than the memory increment size.
 212          */
 213         return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
 214 }
 215
 216 #ifdef CONFIG_MEMORY_HOTPLUG
 217
 218 #ifdef CONFIG_CMA
 219
 220 /* Prevent memory blocks which contain cma regions from going offline */
 221
 222 struct s390_cma_mem_data {
 223         unsigned long start;
 224         unsigned long end;
 225 };
 226
 227 static int s390_cma_check_range(struct cma *cma, void *data)
 228 {
 229         struct s390_cma_mem_data *mem_data;
 230         unsigned long start, end;
 231
 232         mem_data = data;
 233         start = cma_get_base(cma);
 234         end = start + cma_get_size(cma);
 235         if (end < mem_data->start)
 236                 return 0;
 237         if (start >= mem_data->end)
 238                 return 0;
 239         return -EBUSY;
 240 }
 241
 242 static int s390_cma_mem_notifier(struct notifier_block *nb,
 243                                  unsigned long action, void *data)
 244 {
 245         struct s390_cma_mem_data mem_data;
 246         struct memory_notify *arg;
 247         int rc = 0;
 248
 249         arg = data;
 250         mem_data.start = arg->start_pfn << PAGE_SHIFT;
 251         mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
 252         if (action == MEM_GOING_OFFLINE)
 253                 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
 254         return notifier_from_errno(rc);
 255 }
 256
 257 static struct notifier_block s390_cma_mem_nb = {
 258         .notifier_call = s390_cma_mem_notifier,
 259 };
 260
 261 static int __init s390_cma_mem_init(void)
 262 {
 263         return register_memory_notifier(&s390_cma_mem_nb);
 264 }
 265 device_initcall(s390_cma_mem_init);
 266
 267 #endif /* CONFIG_CMA */
 268
 269 int arch_add_memory(int nid, u64 start, u64 size,
 270                 struct mhp_restrictions *restrictions)
 271 {
 272         unsigned long start_pfn = PFN_DOWN(start);
 273         unsigned long size_pages = PFN_DOWN(size);
 274         int rc;
 275
 276         rc = vmem_add_mapping(start, size);
 277         if (rc)
 278                 return rc;
 279
 280         rc = __add_pages(nid, start_pfn, size_pages, restrictions);
 281         if (rc)
 282                 vmem_remove_mapping(start, size);
 283         return rc;
 284 }
 285
 286 #ifdef CONFIG_MEMORY_HOTREMOVE
 287 void arch_remove_memory(int nid, u64 start, u64 size,
 288                         struct vmem_altmap *altmap)
 289 {
 290         /*
 291          * There is no hardware or firmware interface which could trigger a
 292          * hot memory remove on s390. So there is nothing that needs to be
 293          * implemented.
 294          */
 295         BUG();
 296 }
 297 #endif
 298 #endif /* CONFIG_MEMORY_HOTPLUG */