3 * Copyright IBM Corp. 1999
4 * Author(s): Hartmut Penner (hp@de.ibm.com)
6 * Derived from "arch/i386/mm/init.c"
7 * Copyright (C) 1995 Linus Torvalds
10 #include <linux/signal.h>
11 #include <linux/sched.h>
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/types.h>
16 #include <linux/ptrace.h>
17 #include <linux/mman.h>
19 #include <linux/swap.h>
20 #include <linux/smp.h>
21 #include <linux/init.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/memory.h>
25 #include <linux/pfn.h>
26 #include <linux/poison.h>
27 #include <linux/initrd.h>
28 #include <linux/export.h>
29 #include <linux/gfp.h>
30 #include <linux/memblock.h>
31 #include <asm/processor.h>
32 #include <linux/uaccess.h>
33 #include <asm/pgtable.h>
34 #include <asm/pgalloc.h>
36 #include <asm/lowcore.h>
38 #include <asm/tlbflush.h>
39 #include <asm/sections.h>
40 #include <asm/ctl_reg.h>
42 #include <asm/set_memory.h>
44 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
46 unsigned long empty_zero_page, zero_page_mask;
47 EXPORT_SYMBOL(empty_zero_page);
48 EXPORT_SYMBOL(zero_page_mask);
50 static void __init setup_zero_pages(void)
56 /* Latest machines require a mapping granularity of 512KB */
59 /* Limit number of empty zero pages for small memory sizes */
60 while (order > 2 && (totalram_pages >> 10) < (1UL << order))
63 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
65 panic("Out of memory in setup_zero_pages");
67 page = virt_to_page((void *) empty_zero_page);
68 split_page(page, order);
69 for (i = 1 << order; i > 0; i--) {
70 mark_page_reserved(page);
74 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
78 * paging_init() sets up the page tables
80 void __init paging_init(void)
82 unsigned long max_zone_pfns[MAX_NR_ZONES];
83 unsigned long pgd_type, asce_bits;
86 init_mm.pgd = swapper_pg_dir;
87 if (VMALLOC_END > (1UL << 42)) {
88 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
89 pgd_type = _REGION2_ENTRY_EMPTY;
91 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
92 pgd_type = _REGION3_ENTRY_EMPTY;
94 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
95 S390_lowcore.kernel_asce = init_mm.context.asce;
96 clear_table((unsigned long *) init_mm.pgd, pgd_type,
97 sizeof(unsigned long)*2048);
100 /* enable virtual mapping in kernel mode */
101 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
102 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
103 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
104 psw.mask = __extract_psw();
105 psw_bits(psw).dat = 1;
106 psw_bits(psw).as = PSW_BITS_AS_HOME;
107 __load_psw_mask(psw.mask);
109 sparse_memory_present_with_active_regions(MAX_NUMNODES);
111 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
112 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
113 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
114 free_area_init_nodes(max_zone_pfns);
117 void mark_rodata_ro(void)
119 unsigned long size = __end_ro_after_init - __start_ro_after_init;
121 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
122 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
125 void __init mem_init(void)
127 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
128 cpumask_set_cpu(0, mm_cpumask(&init_mm));
130 set_max_mapnr(max_low_pfn);
131 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
133 /* Setup guest page hinting */
136 /* this will put all low memory onto the freelists */
138 setup_zero_pages(); /* Setup zeroed pages. */
140 mem_init_print_info(NULL);
143 void free_initmem(void)
145 __set_memory((unsigned long) _sinittext,
146 (_einittext - _sinittext) >> PAGE_SHIFT,
147 SET_MEMORY_RW | SET_MEMORY_NX);
148 free_initmem_default(POISON_FREE_INITMEM);
151 #ifdef CONFIG_BLK_DEV_INITRD
152 void __init free_initrd_mem(unsigned long start, unsigned long end)
154 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
159 unsigned long memory_block_size_bytes(void)
162 * Make sure the memory block size is always greater
163 * or equal than the memory increment size.
165 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
168 #ifdef CONFIG_MEMORY_HOTPLUG
169 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
171 unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
172 unsigned long start_pfn = PFN_DOWN(start);
173 unsigned long size_pages = PFN_DOWN(size);
174 pg_data_t *pgdat = NODE_DATA(nid);
178 rc = vmem_add_mapping(start, size);
182 for (i = 0; i < MAX_NR_ZONES; i++) {
183 zone = pgdat->node_zones + i;
184 if (zone_idx(zone) != ZONE_MOVABLE) {
185 /* Add range within existing zone limits, if possible */
186 zone_start_pfn = zone->zone_start_pfn;
187 zone_end_pfn = zone->zone_start_pfn +
190 /* Add remaining range to ZONE_MOVABLE */
191 zone_start_pfn = start_pfn;
192 zone_end_pfn = start_pfn + size_pages;
194 if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
196 nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
197 zone_end_pfn - start_pfn : size_pages;
198 rc = __add_pages(nid, zone, start_pfn, nr_pages);
201 start_pfn += nr_pages;
202 size_pages -= nr_pages;
207 vmem_remove_mapping(start, size);
211 #ifdef CONFIG_MEMORY_HOTREMOVE
212 int arch_remove_memory(u64 start, u64 size)
215 * There is no hardware or firmware interface which could trigger a
216 * hot memory remove on s390. So there is nothing that needs to be
222 #endif /* CONFIG_MEMORY_HOTPLUG */