File: /usr/src/linux/arch/s390x/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 (hpenner@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<2; i++) {
54 __asm__ __volatile__(
55 " slgr %0,%0\n"
56 " ssm %1\n"
57 " tprot 0(%2),0\n"
58 "0: jne 1f\n"
59 " lghi %0,1\n"
60 "1: ssm %3\n"
61 ".section __ex_table,\"a\"\n"
62 " .align 8\n"
63 " .quad 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 += 4;
81 if(pmd_quicklist)
82 pmd_free_slow(pmd_alloc_one_fast(NULL, 0)), freed += 4;
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
129 */
130
131 unsigned long last_valid_pfn;
132
133 void __init paging_init(void)
134 {
135 pgd_t * pg_dir;
136 pmd_t * pm_dir;
137 pte_t * pt_dir;
138 pte_t pte;
139 int i,j,k;
140 unsigned long address=0;
141 unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
142 _REGION_TABLE;
143 unsigned long end_mem = (unsigned long) __va(max_low_pfn*PAGE_SIZE);
144 static const int ssm_mask = 0x04000000L;
145
146 unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
147 unsigned long dma_pfn, high_pfn;
148
149 dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
150 high_pfn = max_low_pfn;
151
152 if (dma_pfn > high_pfn)
153 zones_size[ZONE_DMA] = high_pfn;
154 else {
155 zones_size[ZONE_DMA] = dma_pfn;
156 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
157 }
158
159 /* Initialize mem_map[]. */
160 free_area_init(zones_size);
161
162
163 /*
164 * map whole physical memory to virtual memory (identity mapping)
165 */
166
167 pg_dir = swapper_pg_dir;
168
169 for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
170
171 if (address >= end_mem) {
172 pgd_clear(pg_dir);
173 continue;
174 }
175
176 pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
177 pgd_populate(&init_mm, pg_dir, pm_dir);
178
179 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
180 if (address >= end_mem) {
181 pmd_clear(pm_dir);
182 continue;
183 }
184
185 pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
186 pmd_populate(&init_mm, pm_dir, pt_dir);
187
188 for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
189 pte = mk_pte_phys(address, PAGE_KERNEL);
190 if (address >= end_mem) {
191 pte_clear(&pte);
192 continue;
193 }
194 set_pte(pt_dir, pte);
195 address += PAGE_SIZE;
196 }
197 }
198 }
199
200 /* enable virtual mapping in kernel mode */
201 __asm__ __volatile__("lctlg 1,1,%0\n\t"
202 "lctlg 7,7,%0\n\t"
203 "lctlg 13,13,%0\n\t"
204 "ssm %1"
205 : :"m" (pgdir_k), "m" (ssm_mask));
206
207 local_flush_tlb();
208
209 return;
210 }
211
212 void __init mem_init(void)
213 {
214 unsigned long codesize, reservedpages, datasize, initsize;
215 unsigned long tmp;
216
217 max_mapnr = num_physpages = max_low_pfn;
218 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
219
220 /* clear the zero-page */
221 memset(empty_zero_page, 0, PAGE_SIZE);
222
223 /* this will put all low memory onto the freelists */
224 totalram_pages += free_all_bootmem();
225
226 /* mark usable pages in the mem_map[] and count reserved pages */
227 reservedpages = 0;
228 tmp = 0;
229 do {
230 if (tmp && (tmp & 0x1ff) == 0 &&
231 test_access(tmp * PAGE_SIZE) == 0) {
232 printk("2M Segment 0x%016lX not available\n",
233 tmp * PAGE_SIZE);
234 do {
235 set_bit(PG_reserved, &mem_map[tmp].flags);
236 reservedpages++;
237 tmp++;
238 } while (tmp < max_low_pfn && (tmp & 0x1ff));
239 } else {
240 if (PageReserved(mem_map+tmp))
241 reservedpages++;
242 tmp++;
243 }
244 } while (tmp < max_low_pfn);
245
246 codesize = (unsigned long) &_etext - (unsigned long) &_text;
247 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
248 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
249 printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
250 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
251 max_mapnr << (PAGE_SHIFT-10),
252 codesize >> 10,
253 reservedpages << (PAGE_SHIFT-10),
254 datasize >>10,
255 initsize >> 10);
256 }
257
258 void free_initmem(void)
259 {
260 unsigned long addr;
261
262 addr = (unsigned long)(&__init_begin);
263 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
264 ClearPageReserved(virt_to_page(addr));
265 set_page_count(virt_to_page(addr), 1);
266 free_page(addr);
267 totalram_pages++;
268 }
269 printk ("Freeing unused kernel memory: %ldk freed\n",
270 (&__init_end - &__init_begin) >> 10);
271 }
272
273 #ifdef CONFIG_BLK_DEV_INITRD
274 void free_initrd_mem(unsigned long start, unsigned long end)
275 {
276 if (start < end)
277 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
278 for (; start < end; start += PAGE_SIZE) {
279 ClearPageReserved(virt_to_page(start));
280 set_page_count(virt_to_page(start), 1);
281 free_page(start);
282 totalram_pages++;
283 }
284 }
285 #endif
286
287 void si_meminfo(struct sysinfo *val)
288 {
289 val->totalram = totalram_pages;
290 val->sharedram = 0;
291 val->freeram = nr_free_pages();
292 val->bufferram = atomic_read(&buffermem_pages);
293 val->totalhigh = 0;
294 val->freehigh = 0;
295 val->mem_unit = PAGE_SIZE;
296 }
297
298 /*
299 * Overrides for Emacs so that we follow Linus's tabbing style.
300 * Emacs will notice this stuff at the end of the file and automatically
301 * adjust the settings for this buffer only. This must remain at the end
302 * of the file.
303 * ---------------------------------------------------------------------------
304 * Local variables:
305 * c-indent-level: 4
306 * c-brace-imaginary-offset: 0
307 * c-brace-offset: -4
308 * c-argdecl-indent: 4
309 * c-label-offset: -4
310 * c-continued-statement-offset: 4
311 * c-continued-brace-offset: 0
312 * indent-tabs-mode: nil
313 * tab-width: 8
314 * End:
315 */
316