Merge git://git.infradead.org/mtd-2.6
[linux-2.6] / 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
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 #include <asm/sections.h>
38
39 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
40
41 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
42 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
43
44 void diag10(unsigned long addr)
45 {
46         if (addr >= 0x7ff00000)
47                 return;
48 #ifdef CONFIG_64BIT
49         asm volatile (
50                 "   sam31\n"
51                 "   diag %0,%0,0x10\n"
52                 "0: sam64\n"
53                 ".section __ex_table,\"a\"\n"
54                 "   .align 8\n"
55                 "   .quad 0b, 0b\n"
56                 ".previous\n"
57                 : : "a" (addr));
58 #else
59         asm volatile (
60                 "   diag %0,%0,0x10\n"
61                 "0:\n"
62                 ".section __ex_table,\"a\"\n"
63                 "   .align 4\n"
64                 "   .long 0b, 0b\n"
65                 ".previous\n"
66                 : : "a" (addr));
67 #endif
68 }
69
70 void show_mem(void)
71 {
72         int i, total = 0, reserved = 0;
73         int shared = 0, cached = 0;
74
75         printk("Mem-info:\n");
76         show_free_areas();
77         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
78         i = max_mapnr;
79         while (i-- > 0) {
80                 total++;
81                 if (PageReserved(mem_map+i))
82                         reserved++;
83                 else if (PageSwapCache(mem_map+i))
84                         cached++;
85                 else if (page_count(mem_map+i))
86                         shared += page_count(mem_map+i) - 1;
87         }
88         printk("%d pages of RAM\n",total);
89         printk("%d reserved pages\n",reserved);
90         printk("%d pages shared\n",shared);
91         printk("%d pages swap cached\n",cached);
92 }
93
94 extern unsigned long __initdata zholes_size[];
95 /*
96  * paging_init() sets up the page tables
97  */
98
99 #ifndef CONFIG_64BIT
100 void __init paging_init(void)
101 {
102         pgd_t * pg_dir;
103         pte_t * pg_table;
104         pte_t   pte;
105         int     i;
106         unsigned long tmp;
107         unsigned long pfn = 0;
108         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
109         static const int ssm_mask = 0x04000000L;
110         unsigned long ro_start_pfn, ro_end_pfn;
111         unsigned long zones_size[MAX_NR_ZONES];
112
113         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
114         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
115
116         memset(zones_size, 0, sizeof(zones_size));
117         zones_size[ZONE_DMA] = max_low_pfn;
118         free_area_init_node(0, &contig_page_data, zones_size,
119                             __pa(PAGE_OFFSET) >> PAGE_SHIFT,
120                             zholes_size);
121
122         /* unmap whole virtual address space */
123         
124         pg_dir = swapper_pg_dir;
125
126         for (i = 0; i < PTRS_PER_PGD; i++)
127                 pmd_clear((pmd_t *) pg_dir++);
128                 
129         /*
130          * map whole physical memory to virtual memory (identity mapping) 
131          */
132
133         pg_dir = swapper_pg_dir;
134
135         while (pfn < max_low_pfn) {
136                 /*
137                  * pg_table is physical at this point
138                  */
139                 pg_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
140
141                 pmd_populate_kernel(&init_mm, (pmd_t *) pg_dir, pg_table);
142                 pg_dir++;
143
144                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
145                         if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
146                                 pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
147                         else
148                                 pte = pfn_pte(pfn, PAGE_KERNEL);
149                         if (pfn >= max_low_pfn)
150                                 pte_val(pte) = _PAGE_TYPE_EMPTY;
151                         set_pte(pg_table, pte);
152                         pfn++;
153                 }
154         }
155
156         S390_lowcore.kernel_asce = pgdir_k;
157
158         /* enable virtual mapping in kernel mode */
159         __asm__ __volatile__("    LCTL  1,1,%0\n"
160                              "    LCTL  7,7,%0\n"
161                              "    LCTL  13,13,%0\n"
162                              "    SSM   %1" 
163                              : : "m" (pgdir_k), "m" (ssm_mask));
164
165         local_flush_tlb();
166         return;
167 }
168
169 #else /* CONFIG_64BIT */
170
171 void __init paging_init(void)
172 {
173         pgd_t * pg_dir;
174         pmd_t * pm_dir;
175         pte_t * pt_dir;
176         pte_t   pte;
177         int     i,j,k;
178         unsigned long pfn = 0;
179         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
180           _KERN_REGION_TABLE;
181         static const int ssm_mask = 0x04000000L;
182         unsigned long zones_size[MAX_NR_ZONES];
183         unsigned long dma_pfn, high_pfn;
184         unsigned long ro_start_pfn, ro_end_pfn;
185
186         memset(zones_size, 0, sizeof(zones_size));
187         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
188         high_pfn = max_low_pfn;
189         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
190         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
191
192         if (dma_pfn > high_pfn)
193                 zones_size[ZONE_DMA] = high_pfn;
194         else {
195                 zones_size[ZONE_DMA] = dma_pfn;
196                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
197         }
198
199         /* Initialize mem_map[].  */
200         free_area_init_node(0, &contig_page_data, zones_size,
201                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
202
203         /*
204          * map whole physical memory to virtual memory (identity mapping) 
205          */
206
207         pg_dir = swapper_pg_dir;
208         
209         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
210         
211                 if (pfn >= max_low_pfn) {
212                         pgd_clear(pg_dir);
213                         continue;
214                 }          
215         
216                 pm_dir = (pmd_t *) alloc_bootmem_pages(PAGE_SIZE * 4);
217                 pgd_populate(&init_mm, pg_dir, pm_dir);
218
219                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
220                         if (pfn >= max_low_pfn) {
221                                 pmd_clear(pm_dir);
222                                 continue; 
223                         }          
224                         
225                         pt_dir = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
226                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
227         
228                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
229                                 if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
230                                         pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
231                                 else
232                                         pte = pfn_pte(pfn, PAGE_KERNEL);
233                                 if (pfn >= max_low_pfn)
234                                         pte_val(pte) = _PAGE_TYPE_EMPTY;
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_64BIT */
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         printk("Write protected kernel read-only data: %#lx - %#lx\n",
282                (unsigned long)&__start_rodata,
283                PFN_ALIGN((unsigned long)&__end_rodata) - 1);
284 }
285
286 void free_initmem(void)
287 {
288         unsigned long addr;
289
290         addr = (unsigned long)(&__init_begin);
291         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
292                 ClearPageReserved(virt_to_page(addr));
293                 init_page_count(virt_to_page(addr));
294                 free_page(addr);
295                 totalram_pages++;
296         }
297         printk ("Freeing unused kernel memory: %ldk freed\n",
298                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
299 }
300
301 #ifdef CONFIG_BLK_DEV_INITRD
302 void free_initrd_mem(unsigned long start, unsigned long end)
303 {
304         if (start < end)
305                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
306         for (; start < end; start += PAGE_SIZE) {
307                 ClearPageReserved(virt_to_page(start));
308                 init_page_count(virt_to_page(start));
309                 free_page(start);
310                 totalram_pages++;
311         }
312 }
313 #endif