[S390] Add support for memory hot-add.
[linux-2.6.git] / arch / s390 / mm / init.c
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 void show_mem(void)
46 {
47         unsigned long i, total = 0, reserved = 0;
48         unsigned long shared = 0, cached = 0;
49         unsigned long flags;
50         struct page *page;
51         pg_data_t *pgdat;
52
53         printk("Mem-info:\n");
54         show_free_areas();
55         for_each_online_pgdat(pgdat) {
56                 pgdat_resize_lock(pgdat, &flags);
57                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
58                         if (!pfn_valid(pgdat->node_start_pfn + i))
59                                 continue;
60                         page = pfn_to_page(pgdat->node_start_pfn + i);
61                         total++;
62                         if (PageReserved(page))
63                                 reserved++;
64                         else if (PageSwapCache(page))
65                                 cached++;
66                         else if (page_count(page))
67                                 shared += page_count(page) - 1;
68                 }
69                 pgdat_resize_unlock(pgdat, &flags);
70         }
71         printk("%ld pages of RAM\n", total);
72         printk("%ld reserved pages\n", reserved);
73         printk("%ld pages shared\n", shared);
74         printk("%ld pages swap cached\n", cached);
75 }
76
77 /*
78  * paging_init() sets up the page tables
79  */
80 void __init paging_init(void)
81 {
82         static const int ssm_mask = 0x04000000L;
83         unsigned long max_zone_pfns[MAX_NR_ZONES];
84         unsigned long pgd_type;
85
86         init_mm.pgd = swapper_pg_dir;
87         S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
88 #ifdef CONFIG_64BIT
89         /* A three level page table (4TB) is enough for the kernel space. */
90         S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
91         pgd_type = _REGION3_ENTRY_EMPTY;
92 #else
93         S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
94         pgd_type = _SEGMENT_ENTRY_EMPTY;
95 #endif
96         clear_table((unsigned long *) init_mm.pgd, pgd_type,
97                     sizeof(unsigned long)*2048);
98         vmem_map_init();
99
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         __raw_local_irq_ssm(ssm_mask);
105
106         sparse_memory_present_with_active_regions(MAX_NUMNODES);
107         sparse_init();
108         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
109 #ifdef CONFIG_ZONE_DMA
110         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
111 #endif
112         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
113         free_area_init_nodes(max_zone_pfns);
114 }
115
116 void __init mem_init(void)
117 {
118         unsigned long codesize, reservedpages, datasize, initsize;
119
120         max_mapnr = num_physpages = max_low_pfn;
121         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
122
123         /* clear the zero-page */
124         memset(empty_zero_page, 0, PAGE_SIZE);
125
126         /* Setup guest page hinting */
127         cmma_init();
128
129         /* this will put all low memory onto the freelists */
130         totalram_pages += free_all_bootmem();
131
132         reservedpages = 0;
133
134         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
135         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
136         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
137         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
138                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
139                 max_mapnr << (PAGE_SHIFT-10),
140                 codesize >> 10,
141                 reservedpages << (PAGE_SHIFT-10),
142                 datasize >>10,
143                 initsize >> 10);
144         printk("Write protected kernel read-only data: %#lx - %#lx\n",
145                (unsigned long)&_stext,
146                PFN_ALIGN((unsigned long)&_eshared) - 1);
147 }
148
149 #ifdef CONFIG_DEBUG_PAGEALLOC
150 void kernel_map_pages(struct page *page, int numpages, int enable)
151 {
152         pgd_t *pgd;
153         pud_t *pud;
154         pmd_t *pmd;
155         pte_t *pte;
156         unsigned long address;
157         int i;
158
159         for (i = 0; i < numpages; i++) {
160                 address = page_to_phys(page + i);
161                 pgd = pgd_offset_k(address);
162                 pud = pud_offset(pgd, address);
163                 pmd = pmd_offset(pud, address);
164                 pte = pte_offset_kernel(pmd, address);
165                 if (!enable) {
166                         ptep_invalidate(&init_mm, address, pte);
167                         continue;
168                 }
169                 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
170                 /* Flush cpu write queue. */
171                 mb();
172         }
173 }
174 #endif
175
176 void free_initmem(void)
177 {
178         unsigned long addr;
179
180         addr = (unsigned long)(&__init_begin);
181         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
182                 ClearPageReserved(virt_to_page(addr));
183                 init_page_count(virt_to_page(addr));
184                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
185                 free_page(addr);
186                 totalram_pages++;
187         }
188         printk ("Freeing unused kernel memory: %ldk freed\n",
189                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
190 }
191
192 #ifdef CONFIG_BLK_DEV_INITRD
193 void free_initrd_mem(unsigned long start, unsigned long end)
194 {
195         if (start < end)
196                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
197         for (; start < end; start += PAGE_SIZE) {
198                 ClearPageReserved(virt_to_page(start));
199                 init_page_count(virt_to_page(start));
200                 free_page(start);
201                 totalram_pages++;
202         }
203 }
204 #endif
205
206 #ifdef CONFIG_MEMORY_HOTPLUG
207 int arch_add_memory(int nid, u64 start, u64 size)
208 {
209         struct pglist_data *pgdat;
210         struct zone *zone;
211         int rc;
212
213         pgdat = NODE_DATA(nid);
214         zone = pgdat->node_zones + ZONE_NORMAL;
215         rc = vmem_add_mapping(start, size);
216         if (rc)
217                 return rc;
218         rc = __add_pages(zone, PFN_DOWN(start), PFN_DOWN(size));
219         if (rc)
220                 vmem_remove_mapping(start, size);
221         return rc;
222 }
223 #endif /* CONFIG_MEMORY_HOTPLUG */