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 <asm/processor.h>
30 #include <asm/system.h>
31 #include <asm/uaccess.h>
32 #include <asm/pgtable.h>
33 #include <asm/pgalloc.h>
34 #include <asm/dma.h>
35 #include <asm/lowcore.h>
36 #include <asm/tlb.h>
37 #include <asm/tlbflush.h>
38 #include <asm/sections.h>
39
40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
41
42 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
43 char empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
44
45 /*
46 * paging_init() sets up the page tables
47 */
paging_init(void)48 void __init paging_init(void)
49 {
50 static const int ssm_mask = 0x04000000L;
51 unsigned long max_zone_pfns[MAX_NR_ZONES];
52 unsigned long pgd_type;
53
54 init_mm.pgd = swapper_pg_dir;
55 S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
56 #ifdef CONFIG_64BIT
57 /* A three level page table (4TB) is enough for the kernel space. */
58 S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
59 pgd_type = _REGION3_ENTRY_EMPTY;
60 #else
61 S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
62 pgd_type = _SEGMENT_ENTRY_EMPTY;
63 #endif
64 clear_table((unsigned long *) init_mm.pgd, pgd_type,
65 sizeof(unsigned long)*2048);
66 vmem_map_init();
67
68 /* enable virtual mapping in kernel mode */
69 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
70 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
71 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
72 __raw_local_irq_ssm(ssm_mask);
73
74 sparse_memory_present_with_active_regions(MAX_NUMNODES);
75 sparse_init();
76 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
77 #ifdef CONFIG_ZONE_DMA
78 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
79 #endif
80 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
81 free_area_init_nodes(max_zone_pfns);
82 }
83
mem_init(void)84 void __init mem_init(void)
85 {
86 unsigned long codesize, reservedpages, datasize, initsize;
87
88 max_mapnr = num_physpages = max_low_pfn;
89 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
90
91 /* clear the zero-page */
92 memset(empty_zero_page, 0, PAGE_SIZE);
93
94 /* Setup guest page hinting */
95 cmma_init();
96
97 /* this will put all low memory onto the freelists */
98 totalram_pages += free_all_bootmem();
99
100 reservedpages = 0;
101
102 codesize = (unsigned long) &_etext - (unsigned long) &_text;
103 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
104 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
105 printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
106 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
107 max_mapnr << (PAGE_SHIFT-10),
108 codesize >> 10,
109 reservedpages << (PAGE_SHIFT-10),
110 datasize >>10,
111 initsize >> 10);
112 printk("Write protected kernel read-only data: %#lx - %#lx\n",
113 (unsigned long)&_stext,
114 PFN_ALIGN((unsigned long)&_eshared) - 1);
115 }
116
117 #ifdef CONFIG_DEBUG_PAGEALLOC
kernel_map_pages(struct page * page,int numpages,int enable)118 void kernel_map_pages(struct page *page, int numpages, int enable)
119 {
120 pgd_t *pgd;
121 pud_t *pud;
122 pmd_t *pmd;
123 pte_t *pte;
124 unsigned long address;
125 int i;
126
127 for (i = 0; i < numpages; i++) {
128 address = page_to_phys(page + i);
129 pgd = pgd_offset_k(address);
130 pud = pud_offset(pgd, address);
131 pmd = pmd_offset(pud, address);
132 pte = pte_offset_kernel(pmd, address);
133 if (!enable) {
134 ptep_invalidate(&init_mm, address, pte);
135 continue;
136 }
137 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
138 /* Flush cpu write queue. */
139 mb();
140 }
141 }
142 #endif
143
free_initmem(void)144 void free_initmem(void)
145 {
146 unsigned long addr;
147
148 addr = (unsigned long)(&__init_begin);
149 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
150 ClearPageReserved(virt_to_page(addr));
151 init_page_count(virt_to_page(addr));
152 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
153 free_page(addr);
154 totalram_pages++;
155 }
156 printk ("Freeing unused kernel memory: %ldk freed\n",
157 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
158 }
159
160 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)161 void free_initrd_mem(unsigned long start, unsigned long end)
162 {
163 if (start < end)
164 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
165 for (; start < end; start += PAGE_SIZE) {
166 ClearPageReserved(virt_to_page(start));
167 init_page_count(virt_to_page(start));
168 free_page(start);
169 totalram_pages++;
170 }
171 }
172 #endif
173
174 #ifdef CONFIG_MEMORY_HOTPLUG
arch_add_memory(int nid,u64 start,u64 size)175 int arch_add_memory(int nid, u64 start, u64 size)
176 {
177 struct pglist_data *pgdat;
178 struct zone *zone;
179 int rc;
180
181 pgdat = NODE_DATA(nid);
182 zone = pgdat->node_zones + ZONE_MOVABLE;
183 rc = vmem_add_mapping(start, size);
184 if (rc)
185 return rc;
186 rc = __add_pages(nid, zone, PFN_DOWN(start), PFN_DOWN(size));
187 if (rc)
188 vmem_remove_mapping(start, size);
189 return rc;
190 }
191 #endif /* CONFIG_MEMORY_HOTPLUG */
192