5 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Hartmut Penner (hp@de.ibm.com)
8 * Derived from "arch/i386/mm/init.c"
9 * Copyright (C) 1995 Linus Torvalds
12 #include <linux/signal.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/ptrace.h>
19 #include <linux/mman.h>
21 #include <linux/swap.h>
22 #include <linux/smp.h>
23 #include <linux/init.h>
24 #include <linux/pagemap.h>
25 #include <linux/bootmem.h>
26 #include <linux/pfn.h>
27 #include <linux/poison.h>
28 #include <linux/initrd.h>
29 #include <linux/export.h>
30 #include <linux/gfp.h>
31 #include <asm/processor.h>
32 #include <asm/system.h>
33 #include <asm/uaccess.h>
34 #include <asm/pgtable.h>
35 #include <asm/pgalloc.h>
37 #include <asm/lowcore.h>
39 #include <asm/tlbflush.h>
40 #include <asm/sections.h>
42 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
44 unsigned long empty_zero_page, zero_page_mask;
45 EXPORT_SYMBOL(empty_zero_page);
47 static unsigned long setup_zero_pages(void)
56 switch (cpu_id.machine) {
58 case 0x2064: /* z900 */
59 case 0x2066: /* z900 */
60 case 0x2084: /* z990 */
61 case 0x2086: /* z990 */
62 case 0x2094: /* z9-109 */
63 case 0x2096: /* z9-109 */
66 case 0x2097: /* z10 */
67 case 0x2098: /* z10 */
73 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
75 panic("Out of memory in setup_zero_pages");
77 page = virt_to_page((void *) empty_zero_page);
78 split_page(page, order);
79 for (i = 1 << order; i > 0; i--) {
80 SetPageReserved(page);
84 size = PAGE_SIZE << order;
85 zero_page_mask = (size - 1) & PAGE_MASK;
91 * paging_init() sets up the page tables
93 void __init paging_init(void)
95 unsigned long max_zone_pfns[MAX_NR_ZONES];
96 unsigned long pgd_type;
98 init_mm.pgd = swapper_pg_dir;
99 S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
101 /* A three level page table (4TB) is enough for the kernel space. */
102 S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
103 pgd_type = _REGION3_ENTRY_EMPTY;
105 S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
106 pgd_type = _SEGMENT_ENTRY_EMPTY;
108 clear_table((unsigned long *) init_mm.pgd, pgd_type,
109 sizeof(unsigned long)*2048);
112 /* enable virtual mapping in kernel mode */
113 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
114 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
115 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
116 arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
118 atomic_set(&init_mm.context.attach_count, 1);
120 sparse_memory_present_with_active_regions(MAX_NUMNODES);
122 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
123 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
124 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
125 free_area_init_nodes(max_zone_pfns);
129 void __init mem_init(void)
131 unsigned long codesize, reservedpages, datasize, initsize;
133 max_mapnr = num_physpages = max_low_pfn;
134 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
136 /* Setup guest page hinting */
139 /* this will put all low memory onto the freelists */
140 totalram_pages += free_all_bootmem();
141 totalram_pages -= setup_zero_pages(); /* Setup zeroed pages. */
145 codesize = (unsigned long) &_etext - (unsigned long) &_text;
146 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
147 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
148 printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
149 nr_free_pages() << (PAGE_SHIFT-10),
150 max_mapnr << (PAGE_SHIFT-10),
152 reservedpages << (PAGE_SHIFT-10),
155 printk("Write protected kernel read-only data: %#lx - %#lx\n",
156 (unsigned long)&_stext,
157 PFN_ALIGN((unsigned long)&_eshared) - 1);
160 #ifdef CONFIG_DEBUG_PAGEALLOC
161 void kernel_map_pages(struct page *page, int numpages, int enable)
167 unsigned long address;
170 for (i = 0; i < numpages; i++) {
171 address = page_to_phys(page + i);
172 pgd = pgd_offset_k(address);
173 pud = pud_offset(pgd, address);
174 pmd = pmd_offset(pud, address);
175 pte = pte_offset_kernel(pmd, address);
177 __ptep_ipte(address, pte);
178 pte_val(*pte) = _PAGE_TYPE_EMPTY;
181 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
182 /* Flush cpu write queue. */
188 void free_init_pages(char *what, unsigned long begin, unsigned long end)
190 unsigned long addr = begin;
194 for (; addr < end; addr += PAGE_SIZE) {
195 ClearPageReserved(virt_to_page(addr));
196 init_page_count(virt_to_page(addr));
197 memset((void *)(addr & PAGE_MASK), POISON_FREE_INITMEM,
202 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
205 void free_initmem(void)
207 free_init_pages("unused kernel memory",
208 (unsigned long)&__init_begin,
209 (unsigned long)&__init_end);
212 #ifdef CONFIG_BLK_DEV_INITRD
213 void free_initrd_mem(unsigned long start, unsigned long end)
215 free_init_pages("initrd memory", start, end);
219 #ifdef CONFIG_MEMORY_HOTPLUG
220 int arch_add_memory(int nid, u64 start, u64 size)
222 struct pglist_data *pgdat;
226 pgdat = NODE_DATA(nid);
227 zone = pgdat->node_zones + ZONE_MOVABLE;
228 rc = vmem_add_mapping(start, size);
231 rc = __add_pages(nid, zone, PFN_DOWN(start), PFN_DOWN(size));
233 vmem_remove_mapping(start, size);
236 #endif /* CONFIG_MEMORY_HOTPLUG */