m68k: Kill several external declarations in source files
[linux-2.6.git] / arch / s390 / mm / vmem.c
1 /*
2  *  arch/s390/mm/vmem.c
3  *
4  *    Copyright IBM Corp. 2006
5  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
6  */
7
8 #include <linux/bootmem.h>
9 #include <linux/pfn.h>
10 #include <linux/mm.h>
11 #include <linux/module.h>
12 #include <linux/list.h>
13 #include <linux/hugetlb.h>
14 #include <asm/pgalloc.h>
15 #include <asm/pgtable.h>
16 #include <asm/setup.h>
17 #include <asm/tlbflush.h>
18 #include <asm/sections.h>
19
20 static DEFINE_MUTEX(vmem_mutex);
21
22 struct memory_segment {
23         struct list_head list;
24         unsigned long start;
25         unsigned long size;
26 };
27
28 static LIST_HEAD(mem_segs);
29
30 static void __ref *vmem_alloc_pages(unsigned int order)
31 {
32         if (slab_is_available())
33                 return (void *)__get_free_pages(GFP_KERNEL, order);
34         return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
35 }
36
37 static inline pud_t *vmem_pud_alloc(void)
38 {
39         pud_t *pud = NULL;
40
41 #ifdef CONFIG_64BIT
42         pud = vmem_alloc_pages(2);
43         if (!pud)
44                 return NULL;
45         clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
46 #endif
47         return pud;
48 }
49
50 static inline pmd_t *vmem_pmd_alloc(void)
51 {
52         pmd_t *pmd = NULL;
53
54 #ifdef CONFIG_64BIT
55         pmd = vmem_alloc_pages(2);
56         if (!pmd)
57                 return NULL;
58         clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
59 #endif
60         return pmd;
61 }
62
63 static pte_t __ref *vmem_pte_alloc(void)
64 {
65         pte_t *pte;
66
67         if (slab_is_available())
68                 pte = (pte_t *) page_table_alloc(&init_mm);
69         else
70                 pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
71         if (!pte)
72                 return NULL;
73         clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY,
74                     PTRS_PER_PTE * sizeof(pte_t));
75         return pte;
76 }
77
78 /*
79  * Add a physical memory range to the 1:1 mapping.
80  */
81 static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
82 {
83         unsigned long address;
84         pgd_t *pg_dir;
85         pud_t *pu_dir;
86         pmd_t *pm_dir;
87         pte_t *pt_dir;
88         pte_t  pte;
89         int ret = -ENOMEM;
90
91         for (address = start; address < start + size; address += PAGE_SIZE) {
92                 pg_dir = pgd_offset_k(address);
93                 if (pgd_none(*pg_dir)) {
94                         pu_dir = vmem_pud_alloc();
95                         if (!pu_dir)
96                                 goto out;
97                         pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
98                 }
99
100                 pu_dir = pud_offset(pg_dir, address);
101                 if (pud_none(*pu_dir)) {
102                         pm_dir = vmem_pmd_alloc();
103                         if (!pm_dir)
104                                 goto out;
105                         pud_populate_kernel(&init_mm, pu_dir, pm_dir);
106                 }
107
108                 pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
109                 pm_dir = pmd_offset(pu_dir, address);
110
111 #ifdef __s390x__
112                 if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
113                     (address + HPAGE_SIZE <= start + size) &&
114                     (address >= HPAGE_SIZE)) {
115                         pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
116                         pmd_val(*pm_dir) = pte_val(pte);
117                         address += HPAGE_SIZE - PAGE_SIZE;
118                         continue;
119                 }
120 #endif
121                 if (pmd_none(*pm_dir)) {
122                         pt_dir = vmem_pte_alloc();
123                         if (!pt_dir)
124                                 goto out;
125                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
126                 }
127
128                 pt_dir = pte_offset_kernel(pm_dir, address);
129                 *pt_dir = pte;
130         }
131         ret = 0;
132 out:
133         flush_tlb_kernel_range(start, start + size);
134         return ret;
135 }
136
137 /*
138  * Remove a physical memory range from the 1:1 mapping.
139  * Currently only invalidates page table entries.
140  */
141 static void vmem_remove_range(unsigned long start, unsigned long size)
142 {
143         unsigned long address;
144         pgd_t *pg_dir;
145         pud_t *pu_dir;
146         pmd_t *pm_dir;
147         pte_t *pt_dir;
148         pte_t  pte;
149
150         pte_val(pte) = _PAGE_TYPE_EMPTY;
151         for (address = start; address < start + size; address += PAGE_SIZE) {
152                 pg_dir = pgd_offset_k(address);
153                 pu_dir = pud_offset(pg_dir, address);
154                 if (pud_none(*pu_dir))
155                         continue;
156                 pm_dir = pmd_offset(pu_dir, address);
157                 if (pmd_none(*pm_dir))
158                         continue;
159
160                 if (pmd_huge(*pm_dir)) {
161                         pmd_clear_kernel(pm_dir);
162                         address += HPAGE_SIZE - PAGE_SIZE;
163                         continue;
164                 }
165
166                 pt_dir = pte_offset_kernel(pm_dir, address);
167                 *pt_dir = pte;
168         }
169         flush_tlb_kernel_range(start, start + size);
170 }
171
172 /*
173  * Add a backed mem_map array to the virtual mem_map array.
174  */
175 int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
176 {
177         unsigned long address, start_addr, end_addr;
178         pgd_t *pg_dir;
179         pud_t *pu_dir;
180         pmd_t *pm_dir;
181         pte_t *pt_dir;
182         pte_t  pte;
183         int ret = -ENOMEM;
184
185         start_addr = (unsigned long) start;
186         end_addr = (unsigned long) (start + nr);
187
188         for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
189                 pg_dir = pgd_offset_k(address);
190                 if (pgd_none(*pg_dir)) {
191                         pu_dir = vmem_pud_alloc();
192                         if (!pu_dir)
193                                 goto out;
194                         pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
195                 }
196
197                 pu_dir = pud_offset(pg_dir, address);
198                 if (pud_none(*pu_dir)) {
199                         pm_dir = vmem_pmd_alloc();
200                         if (!pm_dir)
201                                 goto out;
202                         pud_populate_kernel(&init_mm, pu_dir, pm_dir);
203                 }
204
205                 pm_dir = pmd_offset(pu_dir, address);
206                 if (pmd_none(*pm_dir)) {
207                         pt_dir = vmem_pte_alloc();
208                         if (!pt_dir)
209                                 goto out;
210                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
211                 }
212
213                 pt_dir = pte_offset_kernel(pm_dir, address);
214                 if (pte_none(*pt_dir)) {
215                         unsigned long new_page;
216
217                         new_page =__pa(vmem_alloc_pages(0));
218                         if (!new_page)
219                                 goto out;
220                         pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
221                         *pt_dir = pte;
222                 }
223         }
224         memset(start, 0, nr * sizeof(struct page));
225         ret = 0;
226 out:
227         flush_tlb_kernel_range(start_addr, end_addr);
228         return ret;
229 }
230
231 /*
232  * Add memory segment to the segment list if it doesn't overlap with
233  * an already present segment.
234  */
235 static int insert_memory_segment(struct memory_segment *seg)
236 {
237         struct memory_segment *tmp;
238
239         if (seg->start + seg->size > VMEM_MAX_PHYS ||
240             seg->start + seg->size < seg->start)
241                 return -ERANGE;
242
243         list_for_each_entry(tmp, &mem_segs, list) {
244                 if (seg->start >= tmp->start + tmp->size)
245                         continue;
246                 if (seg->start + seg->size <= tmp->start)
247                         continue;
248                 return -ENOSPC;
249         }
250         list_add(&seg->list, &mem_segs);
251         return 0;
252 }
253
254 /*
255  * Remove memory segment from the segment list.
256  */
257 static void remove_memory_segment(struct memory_segment *seg)
258 {
259         list_del(&seg->list);
260 }
261
262 static void __remove_shared_memory(struct memory_segment *seg)
263 {
264         remove_memory_segment(seg);
265         vmem_remove_range(seg->start, seg->size);
266 }
267
268 int vmem_remove_mapping(unsigned long start, unsigned long size)
269 {
270         struct memory_segment *seg;
271         int ret;
272
273         mutex_lock(&vmem_mutex);
274
275         ret = -ENOENT;
276         list_for_each_entry(seg, &mem_segs, list) {
277                 if (seg->start == start && seg->size == size)
278                         break;
279         }
280
281         if (seg->start != start || seg->size != size)
282                 goto out;
283
284         ret = 0;
285         __remove_shared_memory(seg);
286         kfree(seg);
287 out:
288         mutex_unlock(&vmem_mutex);
289         return ret;
290 }
291
292 int vmem_add_mapping(unsigned long start, unsigned long size)
293 {
294         struct memory_segment *seg;
295         int ret;
296
297         mutex_lock(&vmem_mutex);
298         ret = -ENOMEM;
299         seg = kzalloc(sizeof(*seg), GFP_KERNEL);
300         if (!seg)
301                 goto out;
302         seg->start = start;
303         seg->size = size;
304
305         ret = insert_memory_segment(seg);
306         if (ret)
307                 goto out_free;
308
309         ret = vmem_add_mem(start, size, 0);
310         if (ret)
311                 goto out_remove;
312         goto out;
313
314 out_remove:
315         __remove_shared_memory(seg);
316 out_free:
317         kfree(seg);
318 out:
319         mutex_unlock(&vmem_mutex);
320         return ret;
321 }
322
323 /*
324  * map whole physical memory to virtual memory (identity mapping)
325  * we reserve enough space in the vmalloc area for vmemmap to hotplug
326  * additional memory segments.
327  */
328 void __init vmem_map_init(void)
329 {
330         unsigned long ro_start, ro_end;
331         unsigned long start, end;
332         int i;
333
334         INIT_LIST_HEAD(&init_mm.context.crst_list);
335         INIT_LIST_HEAD(&init_mm.context.pgtable_list);
336         init_mm.context.noexec = 0;
337         ro_start = ((unsigned long)&_stext) & PAGE_MASK;
338         ro_end = PFN_ALIGN((unsigned long)&_eshared);
339         for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
340                 start = memory_chunk[i].addr;
341                 end = memory_chunk[i].addr + memory_chunk[i].size;
342                 if (start >= ro_end || end <= ro_start)
343                         vmem_add_mem(start, end - start, 0);
344                 else if (start >= ro_start && end <= ro_end)
345                         vmem_add_mem(start, end - start, 1);
346                 else if (start >= ro_start) {
347                         vmem_add_mem(start, ro_end - start, 1);
348                         vmem_add_mem(ro_end, end - ro_end, 0);
349                 } else if (end < ro_end) {
350                         vmem_add_mem(start, ro_start - start, 0);
351                         vmem_add_mem(ro_start, end - ro_start, 1);
352                 } else {
353                         vmem_add_mem(start, ro_start - start, 0);
354                         vmem_add_mem(ro_start, ro_end - ro_start, 1);
355                         vmem_add_mem(ro_end, end - ro_end, 0);
356                 }
357         }
358 }
359
360 /*
361  * Convert memory chunk array to a memory segment list so there is a single
362  * list that contains both r/w memory and shared memory segments.
363  */
364 static int __init vmem_convert_memory_chunk(void)
365 {
366         struct memory_segment *seg;
367         int i;
368
369         mutex_lock(&vmem_mutex);
370         for (i = 0; i < MEMORY_CHUNKS; i++) {
371                 if (!memory_chunk[i].size)
372                         continue;
373                 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
374                 if (!seg)
375                         panic("Out of memory...\n");
376                 seg->start = memory_chunk[i].addr;
377                 seg->size = memory_chunk[i].size;
378                 insert_memory_segment(seg);
379         }
380         mutex_unlock(&vmem_mutex);
381         return 0;
382 }
383
384 core_initcall(vmem_convert_memory_chunk);