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/pfn.h>
25 #include <linux/poison.h>
26 #include <linux/initrd.h>
27 #include <linux/export.h>
28 #include <linux/gfp.h>
29 #include <asm/processor.h>
30 #include <asm/uaccess.h>
31 #include <asm/pgtable.h>
32 #include <asm/pgalloc.h>
34 #include <asm/lowcore.h>
36 #include <asm/tlbflush.h>
37 #include <asm/sections.h>
38 #include <asm/ctl_reg.h>
40 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
42 unsigned long empty_zero_page, zero_page_mask;
43 EXPORT_SYMBOL(empty_zero_page);
45 static unsigned long __init setup_zero_pages(void)
54 switch (cpu_id.machine) {
56 case 0x2064: /* z900 */
57 case 0x2066: /* z900 */
58 case 0x2084: /* z990 */
59 case 0x2086: /* z990 */
60 case 0x2094: /* z9-109 */
61 case 0x2096: /* z9-109 */
64 case 0x2097: /* z10 */
65 case 0x2098: /* z10 */
66 case 0x2817: /* z196 */
67 case 0x2818: /* z196 */
70 case 0x2827: /* zEC12 */
75 /* Limit number of empty zero pages for small memory sizes */
76 if (order > 2 && totalram_pages <= 16384)
79 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
81 panic("Out of memory in setup_zero_pages");
83 page = virt_to_page((void *) empty_zero_page);
84 split_page(page, order);
85 for (i = 1 << order; i > 0; i--) {
86 SetPageReserved(page);
90 size = PAGE_SIZE << order;
91 zero_page_mask = (size - 1) & PAGE_MASK;
97 * paging_init() sets up the page tables
99 void __init paging_init(void)
101 unsigned long max_zone_pfns[MAX_NR_ZONES];
102 unsigned long pgd_type, asce_bits;
104 init_mm.pgd = swapper_pg_dir;
106 if (VMALLOC_END > (1UL << 42)) {
107 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
108 pgd_type = _REGION2_ENTRY_EMPTY;
110 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
111 pgd_type = _REGION3_ENTRY_EMPTY;
114 asce_bits = _ASCE_TABLE_LENGTH;
115 pgd_type = _SEGMENT_ENTRY_EMPTY;
117 S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
118 clear_table((unsigned long *) init_mm.pgd, pgd_type,
119 sizeof(unsigned long)*2048);
122 /* enable virtual mapping in kernel mode */
123 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
124 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
125 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
126 arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
128 atomic_set(&init_mm.context.attach_count, 1);
130 sparse_memory_present_with_active_regions(MAX_NUMNODES);
132 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
133 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
134 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
135 free_area_init_nodes(max_zone_pfns);
138 void __init mem_init(void)
140 unsigned long codesize, reservedpages, datasize, initsize;
142 max_mapnr = num_physpages = max_low_pfn;
143 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
145 /* Setup guest page hinting */
148 /* this will put all low memory onto the freelists */
149 totalram_pages += free_all_bootmem();
150 totalram_pages -= setup_zero_pages(); /* Setup zeroed pages. */
154 codesize = (unsigned long) &_etext - (unsigned long) &_text;
155 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
156 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
157 printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
158 nr_free_pages() << (PAGE_SHIFT-10),
159 max_mapnr << (PAGE_SHIFT-10),
161 reservedpages << (PAGE_SHIFT-10),
164 printk("Write protected kernel read-only data: %#lx - %#lx\n",
165 (unsigned long)&_stext,
166 PFN_ALIGN((unsigned long)&_eshared) - 1);
169 void free_init_pages(char *what, unsigned long begin, unsigned long end)
171 unsigned long addr = begin;
175 for (; addr < end; addr += PAGE_SIZE) {
176 ClearPageReserved(virt_to_page(addr));
177 init_page_count(virt_to_page(addr));
178 memset((void *)(addr & PAGE_MASK), POISON_FREE_INITMEM,
183 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
186 void free_initmem(void)
188 free_init_pages("unused kernel memory",
189 (unsigned long)&__init_begin,
190 (unsigned long)&__init_end);
193 #ifdef CONFIG_BLK_DEV_INITRD
194 void __init free_initrd_mem(unsigned long start, unsigned long end)
196 free_init_pages("initrd memory", start, end);
200 #ifdef CONFIG_MEMORY_HOTPLUG
201 int arch_add_memory(int nid, u64 start, u64 size)
203 unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
204 unsigned long start_pfn = PFN_DOWN(start);
205 unsigned long size_pages = PFN_DOWN(size);
209 rc = vmem_add_mapping(start, size);
212 for_each_zone(zone) {
213 if (zone_idx(zone) != ZONE_MOVABLE) {
214 /* Add range within existing zone limits */
215 zone_start_pfn = zone->zone_start_pfn;
216 zone_end_pfn = zone->zone_start_pfn +
219 /* Add remaining range to ZONE_MOVABLE */
220 zone_start_pfn = start_pfn;
221 zone_end_pfn = start_pfn + size_pages;
223 if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
225 nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
226 zone_end_pfn - start_pfn : size_pages;
227 rc = __add_pages(nid, zone, start_pfn, nr_pages);
230 start_pfn += nr_pages;
231 size_pages -= nr_pages;
236 vmem_remove_mapping(start, size);
240 #ifdef CONFIG_MEMORY_HOTREMOVE
241 int arch_remove_memory(u64 start, u64 size)
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
251 #endif /* CONFIG_MEMORY_HOTPLUG */