File: /usr/src/linux/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 #ifdef CONFIG_BLK_DEV_INITRD
26 #include <linux/blk.h>
27 #endif
28 #include <linux/pagemap.h>
29 #include <linux/bootmem.h>
30
31 #include <asm/processor.h>
32 #include <asm/system.h>
33 #include <asm/uaccess.h>
34 #include <asm/pgtable.h>
35 #include <asm/pgalloc.h>
36 #include <asm/dma.h>
37 #include <asm/lowcore.h>
38 #include <asm/tlb.h>
39
40 mmu_gather_t mmu_gathers[NR_CPUS];
41
42 static unsigned long totalram_pages;
43
44 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
45 char empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
46
47 static int test_access(unsigned long loc)
48 {
49 static const int ssm_mask = 0x07000000L;
50 int rc, i;
51
52 rc = 0;
53 for (i=0; i<4; i++) {
54 __asm__ __volatile__(
55 " slr %0,%0\n"
56 " ssm %1\n"
57 " tprot 0(%2),0\n"
58 "0: jne 1f\n"
59 " lhi %0,1\n"
60 "1: ssm %3\n"
61 ".section __ex_table,\"a\"\n"
62 " .align 4\n"
63 " .long 0b,1b\n"
64 ".previous"
65 : "+&d" (rc) : "i" (0), "a" (loc), "m" (ssm_mask)
66 : "cc");
67 if (rc == 0)
68 break;
69 loc += 0x100000;
70 }
71 return rc;
72 }
73
74 int do_check_pgt_cache(int low, int high)
75 {
76 int freed = 0;
77 if(pgtable_cache_size > high) {
78 do {
79 if(pgd_quicklist)
80 free_pgd_slow(get_pgd_fast()), freed += 2;
81 if(pmd_quicklist)
82 pmd_free_slow(pmd_alloc_one_fast(NULL, 0)), freed++;
83 if(pte_quicklist)
84 pte_free_slow(pte_alloc_one_fast(NULL, 0)), freed++;
85 } while(pgtable_cache_size > low);
86 }
87 return freed;
88 }
89
90 void show_mem(void)
91 {
92 int i, total = 0, reserved = 0;
93 int shared = 0, cached = 0;
94
95 printk("Mem-info:\n");
96 show_free_areas();
97 printk("Free swap: %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
98 i = max_mapnr;
99 while (i-- > 0) {
100 total++;
101 if (PageReserved(mem_map+i))
102 reserved++;
103 else if (PageSwapCache(mem_map+i))
104 cached++;
105 else if (page_count(mem_map+i))
106 shared += atomic_read(&mem_map[i].count) - 1;
107 }
108 printk("%d pages of RAM\n",total);
109 printk("%d reserved pages\n",reserved);
110 printk("%d pages shared\n",shared);
111 printk("%d pages swap cached\n",cached);
112 printk("%ld pages in page table cache\n",pgtable_cache_size);
113 show_buffers();
114 }
115
116 /* References to section boundaries */
117
118 extern unsigned long _text;
119 extern unsigned long _etext;
120 extern unsigned long _edata;
121 extern unsigned long __bss_start;
122 extern unsigned long _end;
123
124 extern unsigned long __init_begin;
125 extern unsigned long __init_end;
126
127 /*
128 * paging_init() sets up the page tables - note that the first 4MB are
129 * already mapped by head.S.
130 * paging_init will erase this initial mapping
131 */
132
133 unsigned long last_valid_pfn;
134
135 void __init paging_init(void)
136 {
137 pgd_t * pg_dir;
138 pte_t * pg_table;
139 pte_t pte;
140 int i;
141 unsigned long tmp;
142 unsigned long address=0;
143 unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
144 unsigned long end_mem = (unsigned long) __va(max_low_pfn*PAGE_SIZE);
145 static const int ssm_mask = 0x04000000L;
146
147 /* unmap whole virtual address space */
148
149 pg_dir = swapper_pg_dir;
150
151 for (i=0;i<KERNEL_PGD_PTRS;i++)
152 pmd_clear((pmd_t*)pg_dir++);
153
154 /*
155 * map whole physical memory to virtual memory (identity mapping)
156 */
157
158 pg_dir = swapper_pg_dir;
159
160 while (address < end_mem) {
161 /*
162 * pg_table is physical at this point
163 */
164 pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
165
166 pg_dir->pgd0 = (_PAGE_TABLE | __pa(pg_table));
167 pg_dir->pgd1 = (_PAGE_TABLE | (__pa(pg_table)+1024));
168 pg_dir->pgd2 = (_PAGE_TABLE | (__pa(pg_table)+2048));
169 pg_dir->pgd3 = (_PAGE_TABLE | (__pa(pg_table)+3072));
170 pg_dir++;
171
172 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
173 pte = mk_pte_phys(address, PAGE_KERNEL);
174 if (address >= end_mem)
175 pte_clear(&pte);
176 set_pte(pg_table, pte);
177 address += PAGE_SIZE;
178 }
179 }
180
181 /* enable virtual mapping in kernel mode */
182 __asm__ __volatile__(" LCTL 1,1,%0\n"
183 " LCTL 7,7,%0\n"
184 " LCTL 13,13,%0\n"
185 " SSM %1"
186 : : "m" (pgdir_k), "m" (ssm_mask));
187
188 local_flush_tlb();
189
190 {
191 unsigned long zones_size[MAX_NR_ZONES] = { 0, 0, 0};
192
193 zones_size[ZONE_DMA] = max_low_pfn;
194 free_area_init(zones_size);
195 }
196
197 return;
198 }
199
200 void __init mem_init(void)
201 {
202 int codesize, reservedpages, datasize, initsize;
203 int tmp;
204
205 max_mapnr = num_physpages = max_low_pfn;
206 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
207
208 /* clear the zero-page */
209 memset(empty_zero_page, 0, PAGE_SIZE);
210
211 /* this will put all low memory onto the freelists */
212 totalram_pages += free_all_bootmem();
213
214 /* mark usable pages in the mem_map[] and count reserved pages */
215 reservedpages = 0;
216 tmp = 0;
217 do {
218 if (tmp && (tmp & 0x3ff) == 0 &&
219 test_access(tmp * PAGE_SIZE) == 0) {
220 printk("4M Segment %lX not available\n",tmp*PAGE_SIZE);
221 do {
222 set_bit(PG_reserved, &mem_map[tmp].flags);
223 reservedpages++;
224 tmp++;
225 } while (tmp < max_low_pfn && (tmp & 0x3ff));
226 } else {
227 if (PageReserved(mem_map+tmp))
228 reservedpages++;
229 tmp++;
230 }
231 } while (tmp < max_low_pfn);
232
233 codesize = (unsigned long) &_etext - (unsigned long) &_text;
234 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
235 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
236 printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n",
237 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
238 max_mapnr << (PAGE_SHIFT-10),
239 codesize >> 10,
240 reservedpages << (PAGE_SHIFT-10),
241 datasize >>10,
242 initsize >> 10);
243 }
244
245 void free_initmem(void)
246 {
247 unsigned long addr;
248
249 addr = (unsigned long)(&__init_begin);
250 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
251 ClearPageReserved(virt_to_page(addr));
252 set_page_count(virt_to_page(addr), 1);
253 free_page(addr);
254 totalram_pages++;
255 }
256 printk ("Freeing unused kernel memory: %dk freed\n",
257 (&__init_end - &__init_begin) >> 10);
258 }
259
260 #ifdef CONFIG_BLK_DEV_INITRD
261 void free_initrd_mem(unsigned long start, unsigned long end)
262 {
263 if (start < end)
264 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
265 for (; start < end; start += PAGE_SIZE) {
266 ClearPageReserved(virt_to_page(start));
267 set_page_count(virt_to_page(start), 1);
268 free_page(start);
269 totalram_pages++;
270 }
271 }
272 #endif
273
274 void si_meminfo(struct sysinfo *val)
275 {
276 val->totalram = totalram_pages;
277 val->sharedram = 0;
278 val->freeram = nr_free_pages();
279 val->bufferram = atomic_read(&buffermem_pages);
280 val->totalhigh = 0;
281 val->freehigh = 0;
282 val->mem_unit = PAGE_SIZE;
283 }
284