init.c revision 238ec4efeee4461d5cff2ed3e5a15a3ab850959b 
1/*
2 *  arch/s390/mm/init.c
3 *
4 *  S390 version
5 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 *    Author(s): Hartmut Penner (hp@de.ibm.com)
7 *
8 *  Derived from "arch/i386/mm/init.c"
9 *    Copyright (C) 1995  Linus Torvalds
10 */
11
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>
20#include <linux/mm.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/gfp.h>
30#include <asm/processor.h>
31#include <asm/system.h>
32#include <asm/uaccess.h>
33#include <asm/pgtable.h>
34#include <asm/pgalloc.h>
35#include <asm/dma.h>
36#include <asm/lowcore.h>
37#include <asm/tlb.h>
38#include <asm/tlbflush.h>
39#include <asm/sections.h>
40
41DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
42
43pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
44
45unsigned long empty_zero_page, zero_page_mask;
46EXPORT_SYMBOL(empty_zero_page);
47
48static unsigned long setup_zero_pages(void)
49{
50	struct cpuid cpu_id;
51	unsigned int order;
52	unsigned long size;
53	struct page *page;
54	int i;
55
56	get_cpu_id(&cpu_id);
57	switch (cpu_id.machine) {
58	case 0x9672:	/* g5 */
59	case 0x2064:	/* z900 */
60	case 0x2066:	/* z900 */
61	case 0x2084:	/* z990 */
62	case 0x2086:	/* z990 */
63	case 0x2094:	/* z9-109 */
64	case 0x2096:	/* z9-109 */
65		order = 0;
66		break;
67	case 0x2097:	/* z10 */
68	case 0x2098:	/* z10 */
69	default:
70		order = 2;
71		break;
72	}
73
74	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
75	if (!empty_zero_page)
76		panic("Out of memory in setup_zero_pages");
77
78	page = virt_to_page((void *) empty_zero_page);
79	split_page(page, order);
80	for (i = 1 << order; i > 0; i--) {
81		SetPageReserved(page);
82		page++;
83	}
84
85	size = PAGE_SIZE << order;
86	zero_page_mask = (size - 1) & PAGE_MASK;
87
88	return 1UL << order;
89}
90
91/*
92 * paging_init() sets up the page tables
93 */
94void __init paging_init(void)
95{
96	unsigned long max_zone_pfns[MAX_NR_ZONES];
97	unsigned long pgd_type;
98
99	init_mm.pgd = swapper_pg_dir;
100	S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
101#ifdef CONFIG_64BIT
102	/* A three level page table (4TB) is enough for the kernel space. */
103	S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
104	pgd_type = _REGION3_ENTRY_EMPTY;
105#else
106	S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
107	pgd_type = _SEGMENT_ENTRY_EMPTY;
108#endif
109	clear_table((unsigned long *) init_mm.pgd, pgd_type,
110		    sizeof(unsigned long)*2048);
111	vmem_map_init();
112
113        /* enable virtual mapping in kernel mode */
114	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
115	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
116	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
117	arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
118
119	atomic_set(&init_mm.context.attach_count, 1);
120
121	sparse_memory_present_with_active_regions(MAX_NUMNODES);
122	sparse_init();
123	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
124#ifdef CONFIG_ZONE_DMA
125	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
126#endif
127	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
128	free_area_init_nodes(max_zone_pfns);
129}
130
131void __init mem_init(void)
132{
133	unsigned long codesize, reservedpages, datasize, initsize;
134
135        max_mapnr = num_physpages = max_low_pfn;
136        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
137
138	/* Setup guest page hinting */
139	cmma_init();
140
141	/* this will put all low memory onto the freelists */
142	totalram_pages += free_all_bootmem();
143	totalram_pages -= setup_zero_pages();	/* Setup zeroed pages. */
144
145	reservedpages = 0;
146
147	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
148	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
149	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
150        printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
151		nr_free_pages() << (PAGE_SHIFT-10),
152                max_mapnr << (PAGE_SHIFT-10),
153                codesize >> 10,
154                reservedpages << (PAGE_SHIFT-10),
155                datasize >>10,
156                initsize >> 10);
157	printk("Write protected kernel read-only data: %#lx - %#lx\n",
158	       (unsigned long)&_stext,
159	       PFN_ALIGN((unsigned long)&_eshared) - 1);
160}
161
162#ifdef CONFIG_DEBUG_PAGEALLOC
163void kernel_map_pages(struct page *page, int numpages, int enable)
164{
165	pgd_t *pgd;
166	pud_t *pud;
167	pmd_t *pmd;
168	pte_t *pte;
169	unsigned long address;
170	int i;
171
172	for (i = 0; i < numpages; i++) {
173		address = page_to_phys(page + i);
174		pgd = pgd_offset_k(address);
175		pud = pud_offset(pgd, address);
176		pmd = pmd_offset(pud, address);
177		pte = pte_offset_kernel(pmd, address);
178		if (!enable) {
179			ptep_invalidate(&init_mm, address, pte);
180			continue;
181		}
182		*pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
183		/* Flush cpu write queue. */
184		mb();
185	}
186}
187#endif
188
189void free_init_pages(char *what, unsigned long begin, unsigned long end)
190{
191	unsigned long addr = begin;
192
193	if (begin >= end)
194		return;
195	for (; addr < end; addr += PAGE_SIZE) {
196		ClearPageReserved(virt_to_page(addr));
197		init_page_count(virt_to_page(addr));
198		memset((void *)(addr & PAGE_MASK), POISON_FREE_INITMEM,
199		       PAGE_SIZE);
200		free_page(addr);
201		totalram_pages++;
202	}
203	printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
204}
205
206void free_initmem(void)
207{
208	free_init_pages("unused kernel memory",
209			(unsigned long)&__init_begin,
210			(unsigned long)&__init_end);
211}
212
213#ifdef CONFIG_BLK_DEV_INITRD
214void free_initrd_mem(unsigned long start, unsigned long end)
215{
216	free_init_pages("initrd memory", start, end);
217}
218#endif
219
220#ifdef CONFIG_MEMORY_HOTPLUG
221int arch_add_memory(int nid, u64 start, u64 size)
222{
223	struct pglist_data *pgdat;
224	struct zone *zone;
225	int rc;
226
227	pgdat = NODE_DATA(nid);
228	zone = pgdat->node_zones + ZONE_MOVABLE;
229	rc = vmem_add_mapping(start, size);
230	if (rc)
231		return rc;
232	rc = __add_pages(nid, zone, PFN_DOWN(start), PFN_DOWN(size));
233	if (rc)
234		vmem_remove_mapping(start, size);
235	return rc;
236}
237#endif /* CONFIG_MEMORY_HOTPLUG */
238