Linux-2.6.12-rc2
[linux-3.10.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/config.h>
13 #include <linux/signal.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/types.h>
19 #include <linux/ptrace.h>
20 #include <linux/mman.h>
21 #include <linux/mm.h>
22 #include <linux/swap.h>
23 #include <linux/smp.h>
24 #include <linux/init.h>
25 #include <linux/pagemap.h>
26 #include <linux/bootmem.h>
27
28 #include <asm/processor.h>
29 #include <asm/system.h>
30 #include <asm/uaccess.h>
31 #include <asm/pgtable.h>
32 #include <asm/pgalloc.h>
33 #include <asm/dma.h>
34 #include <asm/lowcore.h>
35 #include <asm/tlb.h>
36 #include <asm/tlbflush.h>
37
38 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
39
40 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
41 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
42
43 void diag10(unsigned long addr)
44 {
45         if (addr >= 0x7ff00000)
46                 return;
47 #ifdef __s390x__
48         asm volatile (
49                 "   sam31\n"
50                 "   diag %0,%0,0x10\n"
51                 "0: sam64\n"
52                 ".section __ex_table,\"a\"\n"
53                 "   .align 8\n"
54                 "   .quad 0b, 0b\n"
55                 ".previous\n"
56                 : : "a" (addr));
57 #else
58         asm volatile (
59                 "   diag %0,%0,0x10\n"
60                 "0:\n"
61                 ".section __ex_table,\"a\"\n"
62                 "   .align 4\n"
63                 "   .long 0b, 0b\n"
64                 ".previous\n"
65                 : : "a" (addr));
66 #endif
67 }
68
69 void show_mem(void)
70 {
71         int i, total = 0, reserved = 0;
72         int shared = 0, cached = 0;
73
74         printk("Mem-info:\n");
75         show_free_areas();
76         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
77         i = max_mapnr;
78         while (i-- > 0) {
79                 total++;
80                 if (PageReserved(mem_map+i))
81                         reserved++;
82                 else if (PageSwapCache(mem_map+i))
83                         cached++;
84                 else if (page_count(mem_map+i))
85                         shared += page_count(mem_map+i) - 1;
86         }
87         printk("%d pages of RAM\n",total);
88         printk("%d reserved pages\n",reserved);
89         printk("%d pages shared\n",shared);
90         printk("%d pages swap cached\n",cached);
91 }
92
93 /* References to section boundaries */
94
95 extern unsigned long _text;
96 extern unsigned long _etext;
97 extern unsigned long _edata;
98 extern unsigned long __bss_start;
99 extern unsigned long _end;
100
101 extern unsigned long __init_begin;
102 extern unsigned long __init_end;
103
104 /*
105  * paging_init() sets up the page tables
106  */
107
108 #ifndef CONFIG_ARCH_S390X
109 void __init paging_init(void)
110 {
111         pgd_t * pg_dir;
112         pte_t * pg_table;
113         pte_t   pte;
114         int     i;
115         unsigned long tmp;
116         unsigned long pfn = 0;
117         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
118         static const int ssm_mask = 0x04000000L;
119
120         /* unmap whole virtual address space */
121         
122         pg_dir = swapper_pg_dir;
123
124         for (i=0;i<KERNEL_PGD_PTRS;i++) 
125                 pmd_clear((pmd_t*)pg_dir++);
126                 
127         /*
128          * map whole physical memory to virtual memory (identity mapping) 
129          */
130
131         pg_dir = swapper_pg_dir;
132
133         while (pfn < max_low_pfn) {
134                 /*
135                  * pg_table is physical at this point
136                  */
137                 pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
138
139                 pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));
140                 pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));
141                 pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));
142                 pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));
143                 pg_dir++;
144
145                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
146                         pte = pfn_pte(pfn, PAGE_KERNEL);
147                         if (pfn >= max_low_pfn)
148                                 pte_clear(&init_mm, 0, &pte);
149                         set_pte(pg_table, pte);
150                         pfn++;
151                 }
152         }
153
154         S390_lowcore.kernel_asce = pgdir_k;
155
156         /* enable virtual mapping in kernel mode */
157         __asm__ __volatile__("    LCTL  1,1,%0\n"
158                              "    LCTL  7,7,%0\n"
159                              "    LCTL  13,13,%0\n"
160                              "    SSM   %1" 
161                              : : "m" (pgdir_k), "m" (ssm_mask));
162
163         local_flush_tlb();
164
165         {
166                 unsigned long zones_size[MAX_NR_ZONES] = { 0, 0, 0};
167
168                 zones_size[ZONE_DMA] = max_low_pfn;
169                 free_area_init(zones_size);
170         }
171         return;
172 }
173
174 #else /* CONFIG_ARCH_S390X */
175 void __init paging_init(void)
176 {
177         pgd_t * pg_dir;
178         pmd_t * pm_dir;
179         pte_t * pt_dir;
180         pte_t   pte;
181         int     i,j,k;
182         unsigned long pfn = 0;
183         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
184           _KERN_REGION_TABLE;
185         static const int ssm_mask = 0x04000000L;
186
187         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
188         unsigned long dma_pfn, high_pfn;
189
190         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
191         high_pfn = max_low_pfn;
192
193         if (dma_pfn > high_pfn)
194                 zones_size[ZONE_DMA] = high_pfn;
195         else {
196                 zones_size[ZONE_DMA] = dma_pfn;
197                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
198         }
199
200         /* Initialize mem_map[].  */
201         free_area_init(zones_size);
202
203
204         /*
205          * map whole physical memory to virtual memory (identity mapping) 
206          */
207
208         pg_dir = swapper_pg_dir;
209         
210         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
211         
212                 if (pfn >= max_low_pfn) {
213                         pgd_clear(pg_dir);
214                         continue;
215                 }          
216         
217                 pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
218                 pgd_populate(&init_mm, pg_dir, pm_dir);
219
220                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
221                         if (pfn >= max_low_pfn) {
222                                 pmd_clear(pm_dir);
223                                 continue; 
224                         }          
225                         
226                         pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
227                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
228         
229                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
230                                 pte = pfn_pte(pfn, PAGE_KERNEL);
231                                 if (pfn >= max_low_pfn) {
232                                         pte_clear(&init_mm, 0, &pte); 
233                                         continue;
234                                 }
235                                 set_pte(pt_dir, pte);
236                                 pfn++;
237                         }
238                 }
239         }
240
241         S390_lowcore.kernel_asce = pgdir_k;
242
243         /* enable virtual mapping in kernel mode */
244         __asm__ __volatile__("lctlg 1,1,%0\n\t"
245                              "lctlg 7,7,%0\n\t"
246                              "lctlg 13,13,%0\n\t"
247                              "ssm   %1"
248                              : :"m" (pgdir_k), "m" (ssm_mask));
249
250         local_flush_tlb();
251
252         return;
253 }
254 #endif /* CONFIG_ARCH_S390X */
255
256 void __init mem_init(void)
257 {
258         unsigned long codesize, reservedpages, datasize, initsize;
259
260         max_mapnr = num_physpages = max_low_pfn;
261         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
262
263         /* clear the zero-page */
264         memset(empty_zero_page, 0, PAGE_SIZE);
265
266         /* this will put all low memory onto the freelists */
267         totalram_pages += free_all_bootmem();
268
269         reservedpages = 0;
270
271         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
272         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
273         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
274         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
275                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
276                 max_mapnr << (PAGE_SHIFT-10),
277                 codesize >> 10,
278                 reservedpages << (PAGE_SHIFT-10),
279                 datasize >>10,
280                 initsize >> 10);
281 }
282
283 void free_initmem(void)
284 {
285         unsigned long addr;
286
287         addr = (unsigned long)(&__init_begin);
288         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
289                 ClearPageReserved(virt_to_page(addr));
290                 set_page_count(virt_to_page(addr), 1);
291                 free_page(addr);
292                 totalram_pages++;
293         }
294         printk ("Freeing unused kernel memory: %ldk freed\n",
295                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
296 }
297
298 #ifdef CONFIG_BLK_DEV_INITRD
299 void free_initrd_mem(unsigned long start, unsigned long end)
300 {
301         if (start < end)
302                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
303         for (; start < end; start += PAGE_SIZE) {
304                 ClearPageReserved(virt_to_page(start));
305                 set_page_count(virt_to_page(start), 1);
306                 free_page(start);
307                 totalram_pages++;
308         }
309 }
310 #endif