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