[S390] guest page hinting light
[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         int i, total = 0, reserved = 0;
48         int shared = 0, cached = 0;
49         struct page *page;
50
51         printk("Mem-info:\n");
52         show_free_areas();
53         i = max_mapnr;
54         while (i-- > 0) {
55                 if (!pfn_valid(i))
56                         continue;
57                 page = pfn_to_page(i);
58                 total++;
59                 if (PageReserved(page))
60                         reserved++;
61                 else if (PageSwapCache(page))
62                         cached++;
63                 else if (page_count(page))
64                         shared += page_count(page) - 1;
65         }
66         printk("%d pages of RAM\n", total);
67         printk("%d reserved pages\n", reserved);
68         printk("%d pages shared\n", shared);
69         printk("%d pages swap cached\n", cached);
70
71         printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
72         printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK));
73         printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
74         printk("%lu pages slab\n",
75                global_page_state(NR_SLAB_RECLAIMABLE) +
76                global_page_state(NR_SLAB_UNRECLAIMABLE));
77         printk("%lu pages pagetables\n", global_page_state(NR_PAGETABLE));
78 }
79
80 /*
81  * paging_init() sets up the page tables
82  */
83 void __init paging_init(void)
84 {
85         static const int ssm_mask = 0x04000000L;
86         unsigned long max_zone_pfns[MAX_NR_ZONES];
87         unsigned long pgd_type;
88
89         init_mm.pgd = swapper_pg_dir;
90         S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
91 #ifdef CONFIG_64BIT
92         /* A three level page table (4TB) is enough for the kernel space. */
93         S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
94         pgd_type = _REGION3_ENTRY_EMPTY;
95 #else
96         S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
97         pgd_type = _SEGMENT_ENTRY_EMPTY;
98 #endif
99         clear_table((unsigned long *) init_mm.pgd, pgd_type,
100                     sizeof(unsigned long)*2048);
101         vmem_map_init();
102
103         /* enable virtual mapping in kernel mode */
104         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
105         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
106         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
107         __raw_local_irq_ssm(ssm_mask);
108
109         sparse_memory_present_with_active_regions(MAX_NUMNODES);
110         sparse_init();
111         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
112 #ifdef CONFIG_ZONE_DMA
113         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
114 #endif
115         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
116         free_area_init_nodes(max_zone_pfns);
117 }
118
119 void __init mem_init(void)
120 {
121         unsigned long codesize, reservedpages, datasize, initsize;
122
123         max_mapnr = num_physpages = max_low_pfn;
124         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
125
126         /* clear the zero-page */
127         memset(empty_zero_page, 0, PAGE_SIZE);
128
129         /* Setup guest page hinting */
130         cmma_init();
131
132         /* this will put all low memory onto the freelists */
133         totalram_pages += free_all_bootmem();
134
135         reservedpages = 0;
136
137         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
138         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
139         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
140         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
141                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
142                 max_mapnr << (PAGE_SHIFT-10),
143                 codesize >> 10,
144                 reservedpages << (PAGE_SHIFT-10),
145                 datasize >>10,
146                 initsize >> 10);
147         printk("Write protected kernel read-only data: %#lx - %#lx\n",
148                (unsigned long)&_stext,
149                PFN_ALIGN((unsigned long)&_eshared) - 1);
150 }
151
152 #ifdef CONFIG_DEBUG_PAGEALLOC
153 void kernel_map_pages(struct page *page, int numpages, int enable)
154 {
155         pgd_t *pgd;
156         pud_t *pud;
157         pmd_t *pmd;
158         pte_t *pte;
159         unsigned long address;
160         int i;
161
162         for (i = 0; i < numpages; i++) {
163                 address = page_to_phys(page + i);
164                 pgd = pgd_offset_k(address);
165                 pud = pud_offset(pgd, address);
166                 pmd = pmd_offset(pud, address);
167                 pte = pte_offset_kernel(pmd, address);
168                 if (!enable) {
169                         ptep_invalidate(&init_mm, address, pte);
170                         continue;
171                 }
172                 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
173                 /* Flush cpu write queue. */
174                 mb();
175         }
176 }
177 #endif
178
179 void free_initmem(void)
180 {
181         unsigned long addr;
182
183         addr = (unsigned long)(&__init_begin);
184         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
185                 ClearPageReserved(virt_to_page(addr));
186                 init_page_count(virt_to_page(addr));
187                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
188                 free_page(addr);
189                 totalram_pages++;
190         }
191         printk ("Freeing unused kernel memory: %ldk freed\n",
192                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
193 }
194
195 #ifdef CONFIG_BLK_DEV_INITRD
196 void free_initrd_mem(unsigned long start, unsigned long end)
197 {
198         if (start < end)
199                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
200         for (; start < end; start += PAGE_SIZE) {
201                 ClearPageReserved(virt_to_page(start));
202                 init_page_count(virt_to_page(start));
203                 free_page(start);
204                 totalram_pages++;
205         }
206 }
207 #endif