linux/arch/s390/mm/init.c
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   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
  46pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
  47
  48unsigned long empty_zero_page, zero_page_mask;
  49EXPORT_SYMBOL(empty_zero_page);
  50EXPORT_SYMBOL(zero_page_mask);
  51
  52static 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 */
  82void __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
 119void 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
 127void __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
 147void 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
 156void __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
 163unsigned 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
 178struct s390_cma_mem_data {
 179        unsigned long start;
 180        unsigned long end;
 181};
 182
 183static 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
 198static 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
 213static struct notifier_block s390_cma_mem_nb = {
 214        .notifier_call = s390_cma_mem_notifier,
 215};
 216
 217static int __init s390_cma_mem_init(void)
 218{
 219        return register_memory_notifier(&s390_cma_mem_nb);
 220}
 221device_initcall(s390_cma_mem_init);
 222
 223#endif /* CONFIG_CMA */
 224
 225int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 226                bool want_memblock)
 227{
 228        unsigned long start_pfn = PFN_DOWN(start);
 229        unsigned long size_pages = PFN_DOWN(size);
 230        int rc;
 231
 232        rc = vmem_add_mapping(start, size);
 233        if (rc)
 234                return rc;
 235
 236        rc = __add_pages(nid, start_pfn, size_pages, altmap, want_memblock);
 237        if (rc)
 238                vmem_remove_mapping(start, size);
 239        return rc;
 240}
 241
 242#ifdef CONFIG_MEMORY_HOTREMOVE
 243int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
 244{
 245        /*
 246         * There is no hardware or firmware interface which could trigger a
 247         * hot memory remove on s390. So there is nothing that needs to be
 248         * implemented.
 249         */
 250        return -EBUSY;
 251}
 252#endif
 253#endif /* CONFIG_MEMORY_HOTPLUG */
 254