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         crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
  99         vmem_map_init();
 100
 101         /* enable virtual mapping in kernel mode */
 102         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 103         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 104         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 105         psw.mask = __extract_psw();
 106         psw_bits(psw).dat = 1;
 107         psw_bits(psw).as = PSW_BITS_AS_HOME;
 108         __load_psw_mask(psw.mask);
 109
 110         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 111         sparse_init();
 112         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 113         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 114         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 115         free_area_init_nodes(max_zone_pfns);
 116 }
 117
 118 void mark_rodata_ro(void)
 119 {
 120         unsigned long size = __end_ro_after_init - __start_ro_after_init;
 121
 122         set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
 123         pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
 124 }
 125
 126 void __init mem_init(void)
 127 {
 128         cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
 129         cpumask_set_cpu(0, mm_cpumask(&init_mm));
 130
 131         set_max_mapnr(max_low_pfn);
 132         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 133
 134         /* Setup guest page hinting */
 135         cmma_init();
 136
 137         /* this will put all low memory onto the freelists */
 138         free_all_bootmem();
 139         setup_zero_pages();     /* Setup zeroed pages. */
 140
 141         cmma_init_nodat();
 142
 143         mem_init_print_info(NULL);
 144 }
 145
 146 void free_initmem(void)
 147 {
 148         __set_memory((unsigned long) _sinittext,
 149                      (_einittext - _sinittext) >> PAGE_SHIFT,
 150                      SET_MEMORY_RW | SET_MEMORY_NX);
 151         free_initmem_default(POISON_FREE_INITMEM);
 152 }
 153
 154 #ifdef CONFIG_BLK_DEV_INITRD
 155 void __init free_initrd_mem(unsigned long start, unsigned long end)
 156 {
 157         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 158                            "initrd");
 159 }
 160 #endif
 161
 162 unsigned long memory_block_size_bytes(void)
 163 {
 164         /*
 165          * Make sure the memory block size is always greater
 166          * or equal than the memory increment size.
 167          */
 168         return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
 169 }
 170
 171 #ifdef CONFIG_MEMORY_HOTPLUG
 172
 173 #ifdef CONFIG_CMA
 174
 175 /* Prevent memory blocks which contain cma regions from going offline */
 176
 177 struct s390_cma_mem_data {
 178         unsigned long start;
 179         unsigned long end;
 180 };
 181
 182 static int s390_cma_check_range(struct cma *cma, void *data)
 183 {
 184         struct s390_cma_mem_data *mem_data;
 185         unsigned long start, end;
 186
 187         mem_data = data;
 188         start = cma_get_base(cma);
 189         end = start + cma_get_size(cma);
 190         if (end < mem_data->start)
 191                 return 0;
 192         if (start >= mem_data->end)
 193                 return 0;
 194         return -EBUSY;
 195 }
 196
 197 static int s390_cma_mem_notifier(struct notifier_block *nb,
 198                                  unsigned long action, void *data)
 199 {
 200         struct s390_cma_mem_data mem_data;
 201         struct memory_notify *arg;
 202         int rc = 0;
 203
 204         arg = data;
 205         mem_data.start = arg->start_pfn << PAGE_SHIFT;
 206         mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
 207         if (action == MEM_GOING_OFFLINE)
 208                 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
 209         return notifier_from_errno(rc);
 210 }
 211
 212 static struct notifier_block s390_cma_mem_nb = {
 213         .notifier_call = s390_cma_mem_notifier,
 214 };
 215
 216 static int __init s390_cma_mem_init(void)
 217 {
 218         return register_memory_notifier(&s390_cma_mem_nb);
 219 }
 220 device_initcall(s390_cma_mem_init);
 221
 222 #endif /* CONFIG_CMA */
 223
 224 int arch_add_memory(int nid, u64 start, u64 size, bool want_memblock)
 225 {
 226         unsigned long start_pfn = PFN_DOWN(start);
 227         unsigned long size_pages = PFN_DOWN(size);
 228         int rc;
 229
 230         rc = vmem_add_mapping(start, size);
 231         if (rc)
 232                 return rc;
 233
 234         rc = __add_pages(nid, start_pfn, size_pages, want_memblock);
 235         if (rc)
 236                 vmem_remove_mapping(start, size);
 237         return rc;
 238 }
 239
 240 #ifdef CONFIG_MEMORY_HOTREMOVE
 241 int arch_remove_memory(u64 start, u64 size)
 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         return -EBUSY;
 249 }
 250 #endif
 251 #endif /* CONFIG_MEMORY_HOTPLUG */