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/smp.h>
  22 #include <linux/init.h>
  23 #include <linux/pagemap.h>
  24 #include <linux/memblock.h>
  25 #include <linux/memory.h>
  26 #include <linux/pfn.h>
  27 #include <linux/poison.h>
  28 #include <linux/initrd.h>
  29 #include <linux/export.h>
  30 #include <linux/cma.h>
  31 #include <linux/gfp.h>
  32 #include <asm/processor.h>
  33 #include <linux/uaccess.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/pgalloc.h>
  36 #include <asm/dma.h>
  37 #include <asm/lowcore.h>
  38 #include <asm/tlb.h>
  39 #include <asm/tlbflush.h>
  40 #include <asm/sections.h>
  41 #include <asm/ctl_reg.h>
  42 #include <asm/sclp.h>
  43 #include <asm/set_memory.h>
  44 #include <asm/kasan.h>
  45
  46 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
  47
  48 unsigned long empty_zero_page, zero_page_mask;
  49 EXPORT_SYMBOL(empty_zero_page);
  50 EXPORT_SYMBOL(zero_page_mask);
  51
  52 bool initmem_freed;
  53
  54 static void __init setup_zero_pages(void)
  55 {
  56         unsigned int order;
  57         struct page *page;
  58         int i;
  59
  60         /* Latest machines require a mapping granularity of 512KB */
  61         order = 7;
  62
  63         /* Limit number of empty zero pages for small memory sizes */
  64         while (order > 2 && (totalram_pages() >> 10) < (1UL << order))
  65                 order--;
  66
  67         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  68         if (!empty_zero_page)
  69                 panic("Out of memory in setup_zero_pages");
  70
  71         page = virt_to_page((void *) empty_zero_page);
  72         split_page(page, order);
  73         for (i = 1 << order; i > 0; i--) {
  74                 mark_page_reserved(page);
  75                 page++;
  76         }
  77
  78         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  79 }
  80
  81 /*
  82  * paging_init() sets up the page tables
  83  */
  84 void __init paging_init(void)
  85 {
  86         unsigned long max_zone_pfns[MAX_NR_ZONES];
  87         unsigned long pgd_type, asce_bits;
  88         psw_t psw;
  89
  90         init_mm.pgd = swapper_pg_dir;
  91         if (VMALLOC_END > _REGION2_SIZE) {
  92                 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
  93                 pgd_type = _REGION2_ENTRY_EMPTY;
  94         } else {
  95                 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
  96                 pgd_type = _REGION3_ENTRY_EMPTY;
  97         }
  98         init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
  99         S390_lowcore.kernel_asce = init_mm.context.asce;
 100         S390_lowcore.user_asce = S390_lowcore.kernel_asce;
 101         crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
 102         vmem_map_init();
 103         kasan_copy_shadow(init_mm.pgd);
 104
 105         /* enable virtual mapping in kernel mode */
 106         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 107         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 108         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 109         psw.mask = __extract_psw();
 110         psw_bits(psw).dat = 1;
 111         psw_bits(psw).as = PSW_BITS_AS_HOME;
 112         __load_psw_mask(psw.mask);
 113         kasan_free_early_identity();
 114
 115         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 116         sparse_init();
 117         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 118         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 119         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 120         free_area_init_nodes(max_zone_pfns);
 121 }
 122
 123 void mark_rodata_ro(void)
 124 {
 125         unsigned long size = __end_ro_after_init - __start_ro_after_init;
 126
 127         set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
 128         pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
 129 }
 130
 131 void __init mem_init(void)
 132 {
 133         cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
 134         cpumask_set_cpu(0, mm_cpumask(&init_mm));
 135
 136         set_max_mapnr(max_low_pfn);
 137         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 138
 139         /* Setup guest page hinting */
 140         cmma_init();
 141
 142         /* this will put all low memory onto the freelists */
 143         memblock_free_all();
 144         setup_zero_pages();     /* Setup zeroed pages. */
 145
 146         cmma_init_nodat();
 147
 148         mem_init_print_info(NULL);
 149 }
 150
 151 void free_initmem(void)
 152 {
 153         initmem_freed = true;
 154         __set_memory((unsigned long)_sinittext,
 155                      (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
 156                      SET_MEMORY_RW | SET_MEMORY_NX);
 157         free_initmem_default(POISON_FREE_INITMEM);
 158 }
 159
 160 unsigned long memory_block_size_bytes(void)
 161 {
 162         /*
 163          * Make sure the memory block size is always greater
 164          * or equal than the memory increment size.
 165          */
 166         return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
 167 }
 168
 169 #ifdef CONFIG_MEMORY_HOTPLUG
 170
 171 #ifdef CONFIG_CMA
 172
 173 /* Prevent memory blocks which contain cma regions from going offline */
 174
 175 struct s390_cma_mem_data {
 176         unsigned long start;
 177         unsigned long end;
 178 };
 179
 180 static int s390_cma_check_range(struct cma *cma, void *data)
 181 {
 182         struct s390_cma_mem_data *mem_data;
 183         unsigned long start, end;
 184
 185         mem_data = data;
 186         start = cma_get_base(cma);
 187         end = start + cma_get_size(cma);
 188         if (end < mem_data->start)
 189                 return 0;
 190         if (start >= mem_data->end)
 191                 return 0;
 192         return -EBUSY;
 193 }
 194
 195 static int s390_cma_mem_notifier(struct notifier_block *nb,
 196                                  unsigned long action, void *data)
 197 {
 198         struct s390_cma_mem_data mem_data;
 199         struct memory_notify *arg;
 200         int rc = 0;
 201
 202         arg = data;
 203         mem_data.start = arg->start_pfn << PAGE_SHIFT;
 204         mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
 205         if (action == MEM_GOING_OFFLINE)
 206                 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
 207         return notifier_from_errno(rc);
 208 }
 209
 210 static struct notifier_block s390_cma_mem_nb = {
 211         .notifier_call = s390_cma_mem_notifier,
 212 };
 213
 214 static int __init s390_cma_mem_init(void)
 215 {
 216         return register_memory_notifier(&s390_cma_mem_nb);
 217 }
 218 device_initcall(s390_cma_mem_init);
 219
 220 #endif /* CONFIG_CMA */
 221
 222 int arch_add_memory(int nid, u64 start, u64 size,
 223                 struct mhp_restrictions *restrictions)
 224 {
 225         unsigned long start_pfn = PFN_DOWN(start);
 226         unsigned long size_pages = PFN_DOWN(size);
 227         int rc;
 228
 229         rc = vmem_add_mapping(start, size);
 230         if (rc)
 231                 return rc;
 232
 233         rc = __add_pages(nid, start_pfn, size_pages, restrictions);
 234         if (rc)
 235                 vmem_remove_mapping(start, size);
 236         return rc;
 237 }
 238
 239 #ifdef CONFIG_MEMORY_HOTREMOVE
 240 void arch_remove_memory(int nid, u64 start, u64 size,
 241                         struct vmem_altmap *altmap)
 242 {
 243         /*
 244          * There is no hardware or firmware interface which could trigger a
 245          * hot memory remove on s390. So there is nothing that needs to be
 246          * implemented.
 247          */
 248         BUG();
 249 }
 250 #endif
 251 #endif /* CONFIG_MEMORY_HOTPLUG */