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/bootmem.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 <linux/memblock.h>
  33 #include <asm/processor.h>
  34 #include <linux/uaccess.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/pgalloc.h>
  37 #include <asm/dma.h>
  38 #include <asm/lowcore.h>
  39 #include <asm/tlb.h>
  40 #include <asm/tlbflush.h>
  41 #include <asm/sections.h>
  42 #include <asm/ctl_reg.h>
  43 #include <asm/sclp.h>
  44 #include <asm/set_memory.h>
  45 #include <asm/kasan.h>
  46
  47 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
  48
  49 unsigned long empty_zero_page, zero_page_mask;
  50 EXPORT_SYMBOL(empty_zero_page);
  51 EXPORT_SYMBOL(zero_page_mask);
  52
  53 static void __init setup_zero_pages(void)
  54 {
  55         unsigned int order;
  56         struct page *page;
  57         int i;
  58
  59         /* Latest machines require a mapping granularity of 512KB */
  60         order = 7;
  61
  62         /* Limit number of empty zero pages for small memory sizes */
  63         while (order > 2 && (totalram_pages >> 10) < (1UL << order))
  64                 order--;
  65
  66         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  67         if (!empty_zero_page)
  68                 panic("Out of memory in setup_zero_pages");
  69
  70         page = virt_to_page((void *) empty_zero_page);
  71         split_page(page, order);
  72         for (i = 1 << order; i > 0; i--) {
  73                 mark_page_reserved(page);
  74                 page++;
  75         }
  76
  77         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  78 }
  79
  80 /*
  81  * paging_init() sets up the page tables
  82  */
  83 void __init paging_init(void)
  84 {
  85         unsigned long max_zone_pfns[MAX_NR_ZONES];
  86         unsigned long pgd_type, asce_bits;
  87         psw_t psw;
  88
  89         init_mm.pgd = swapper_pg_dir;
  90         if (VMALLOC_END > _REGION2_SIZE) {
  91                 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
  92                 pgd_type = _REGION2_ENTRY_EMPTY;
  93         } else {
  94                 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
  95                 pgd_type = _REGION3_ENTRY_EMPTY;
  96         }
  97         init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
  98         S390_lowcore.kernel_asce = init_mm.context.asce;
  99         S390_lowcore.user_asce = S390_lowcore.kernel_asce;
 100         crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
 101         vmem_map_init();
 102         kasan_copy_shadow(init_mm.pgd);
 103
 104         /* enable virtual mapping in kernel mode */
 105         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 106         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 107         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 108         psw.mask = __extract_psw();
 109         psw_bits(psw).dat = 1;
 110         psw_bits(psw).as = PSW_BITS_AS_HOME;
 111         __load_psw_mask(psw.mask);
 112         kasan_free_early_identity();
 113
 114         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 115         sparse_init();
 116         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 117         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 118         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 119         free_area_init_nodes(max_zone_pfns);
 120 }
 121
 122 void mark_rodata_ro(void)
 123 {
 124         unsigned long size = __end_ro_after_init - __start_ro_after_init;
 125
 126         set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
 127         pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
 128 }
 129
 130 void __init mem_init(void)
 131 {
 132         cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
 133         cpumask_set_cpu(0, mm_cpumask(&init_mm));
 134
 135         set_max_mapnr(max_low_pfn);
 136         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 137
 138         /* Setup guest page hinting */
 139         cmma_init();
 140
 141         /* this will put all low memory onto the freelists */
 142         free_all_bootmem();
 143         setup_zero_pages();     /* Setup zeroed pages. */
 144
 145         cmma_init_nodat();
 146
 147         mem_init_print_info(NULL);
 148 }
 149
 150 void free_initmem(void)
 151 {
 152         __set_memory((unsigned long)_sinittext,
 153                      (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
 154                      SET_MEMORY_RW | SET_MEMORY_NX);
 155         free_initmem_default(POISON_FREE_INITMEM);
 156 }
 157
 158 #ifdef CONFIG_BLK_DEV_INITRD
 159 void __init free_initrd_mem(unsigned long start, unsigned long end)
 160 {
 161         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 162                            "initrd");
 163 }
 164 #endif
 165
 166 unsigned long memory_block_size_bytes(void)
 167 {
 168         /*
 169          * Make sure the memory block size is always greater
 170          * or equal than the memory increment size.
 171          */
 172         return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
 173 }
 174
 175 #ifdef CONFIG_MEMORY_HOTPLUG
 176
 177 #ifdef CONFIG_CMA
 178
 179 /* Prevent memory blocks which contain cma regions from going offline */
 180
 181 struct s390_cma_mem_data {
 182         unsigned long start;
 183         unsigned long end;
 184 };
 185
 186 static int s390_cma_check_range(struct cma *cma, void *data)
 187 {
 188         struct s390_cma_mem_data *mem_data;
 189         unsigned long start, end;
 190
 191         mem_data = data;
 192         start = cma_get_base(cma);
 193         end = start + cma_get_size(cma);
 194         if (end < mem_data->start)
 195                 return 0;
 196         if (start >= mem_data->end)
 197                 return 0;
 198         return -EBUSY;
 199 }
 200
 201 static int s390_cma_mem_notifier(struct notifier_block *nb,
 202                                  unsigned long action, void *data)
 203 {
 204         struct s390_cma_mem_data mem_data;
 205         struct memory_notify *arg;
 206         int rc = 0;
 207
 208         arg = data;
 209         mem_data.start = arg->start_pfn << PAGE_SHIFT;
 210         mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
 211         if (action == MEM_GOING_OFFLINE)
 212                 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
 213         return notifier_from_errno(rc);
 214 }
 215
 216 static struct notifier_block s390_cma_mem_nb = {
 217         .notifier_call = s390_cma_mem_notifier,
 218 };
 219
 220 static int __init s390_cma_mem_init(void)
 221 {
 222         return register_memory_notifier(&s390_cma_mem_nb);
 223 }
 224 device_initcall(s390_cma_mem_init);
 225
 226 #endif /* CONFIG_CMA */
 227
 228 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 229                 bool want_memblock)
 230 {
 231         unsigned long start_pfn = PFN_DOWN(start);
 232         unsigned long size_pages = PFN_DOWN(size);
 233         int rc;
 234
 235         rc = vmem_add_mapping(start, size);
 236         if (rc)
 237                 return rc;
 238
 239         rc = __add_pages(nid, start_pfn, size_pages, altmap, want_memblock);
 240         if (rc)
 241                 vmem_remove_mapping(start, size);
 242         return rc;
 243 }
 244
 245 #ifdef CONFIG_MEMORY_HOTREMOVE
 246 int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
 247 {
 248         /*
 249          * There is no hardware or firmware interface which could trigger a
 250          * hot memory remove on s390. So there is nothing that needs to be
 251          * implemented.
 252          */
 253         return -EBUSY;
 254 }
 255 #endif
 256 #endif /* CONFIG_MEMORY_HOTPLUG */