x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1
[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         if (MACHINE_HAS_HPAGE)
74                 clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY | _PAGE_CO,
75                             PTRS_PER_PTE * sizeof(pte_t));
76         else
77                 clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY,
78                             PTRS_PER_PTE * sizeof(pte_t));
79         return pte;
80 }
81
82 /*
83  * Add a physical memory range to the 1:1 mapping.
84  */
85 static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
86 {
87         unsigned long address;
88         pgd_t *pg_dir;
89         pud_t *pu_dir;
90         pmd_t *pm_dir;
91         pte_t *pt_dir;
92         pte_t  pte;
93         int ret = -ENOMEM;
94
95         for (address = start; address < start + size; address += PAGE_SIZE) {
96                 pg_dir = pgd_offset_k(address);
97                 if (pgd_none(*pg_dir)) {
98                         pu_dir = vmem_pud_alloc();
99                         if (!pu_dir)
100                                 goto out;
101                         pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
102                 }
103
104                 pu_dir = pud_offset(pg_dir, address);
105                 if (pud_none(*pu_dir)) {
106                         pm_dir = vmem_pmd_alloc();
107                         if (!pm_dir)
108                                 goto out;
109                         pud_populate_kernel(&init_mm, pu_dir, pm_dir);
110                 }
111
112                 pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
113                 pm_dir = pmd_offset(pu_dir, address);
114
115 #ifdef __s390x__
116                 if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
117                     (address + HPAGE_SIZE <= start + size) &&
118                     (address >= HPAGE_SIZE)) {
119                         pte_val(pte) |= _SEGMENT_ENTRY_LARGE |
120                                         _SEGMENT_ENTRY_CO;
121                         pmd_val(*pm_dir) = pte_val(pte);
122                         address += HPAGE_SIZE - PAGE_SIZE;
123                         continue;
124                 }
125 #endif
126                 if (pmd_none(*pm_dir)) {
127                         pt_dir = vmem_pte_alloc();
128                         if (!pt_dir)
129                                 goto out;
130                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
131                 }
132
133                 pt_dir = pte_offset_kernel(pm_dir, address);
134                 *pt_dir = pte;
135         }
136         ret = 0;
137 out:
138         flush_tlb_kernel_range(start, start + size);
139         return ret;
140 }
141
142 /*
143  * Remove a physical memory range from the 1:1 mapping.
144  * Currently only invalidates page table entries.
145  */
146 static void vmem_remove_range(unsigned long start, unsigned long size)
147 {
148         unsigned long address;
149         pgd_t *pg_dir;
150         pud_t *pu_dir;
151         pmd_t *pm_dir;
152         pte_t *pt_dir;
153         pte_t  pte;
154
155         pte_val(pte) = _PAGE_TYPE_EMPTY;
156         for (address = start; address < start + size; address += PAGE_SIZE) {
157                 pg_dir = pgd_offset_k(address);
158                 pu_dir = pud_offset(pg_dir, address);
159                 if (pud_none(*pu_dir))
160                         continue;
161                 pm_dir = pmd_offset(pu_dir, address);
162                 if (pmd_none(*pm_dir))
163                         continue;
164
165                 if (pmd_huge(*pm_dir)) {
166                         pmd_clear_kernel(pm_dir);
167                         address += HPAGE_SIZE - PAGE_SIZE;
168                         continue;
169                 }
170
171                 pt_dir = pte_offset_kernel(pm_dir, address);
172                 *pt_dir = pte;
173         }
174         flush_tlb_kernel_range(start, start + size);
175 }
176
177 /*
178  * Add a backed mem_map array to the virtual mem_map array.
179  */
180 int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
181 {
182         unsigned long address, start_addr, end_addr;
183         pgd_t *pg_dir;
184         pud_t *pu_dir;
185         pmd_t *pm_dir;
186         pte_t *pt_dir;
187         pte_t  pte;
188         int ret = -ENOMEM;
189
190         start_addr = (unsigned long) start;
191         end_addr = (unsigned long) (start + nr);
192
193         for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
194                 pg_dir = pgd_offset_k(address);
195                 if (pgd_none(*pg_dir)) {
196                         pu_dir = vmem_pud_alloc();
197                         if (!pu_dir)
198                                 goto out;
199                         pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
200                 }
201
202                 pu_dir = pud_offset(pg_dir, address);
203                 if (pud_none(*pu_dir)) {
204                         pm_dir = vmem_pmd_alloc();
205                         if (!pm_dir)
206                                 goto out;
207                         pud_populate_kernel(&init_mm, pu_dir, pm_dir);
208                 }
209
210                 pm_dir = pmd_offset(pu_dir, address);
211                 if (pmd_none(*pm_dir)) {
212                         pt_dir = vmem_pte_alloc();
213                         if (!pt_dir)
214                                 goto out;
215                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
216                 }
217
218                 pt_dir = pte_offset_kernel(pm_dir, address);
219                 if (pte_none(*pt_dir)) {
220                         unsigned long new_page;
221
222                         new_page =__pa(vmem_alloc_pages(0));
223                         if (!new_page)
224                                 goto out;
225                         pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
226                         *pt_dir = pte;
227                 }
228         }
229         memset(start, 0, nr * sizeof(struct page));
230         ret = 0;
231 out:
232         flush_tlb_kernel_range(start_addr, end_addr);
233         return ret;
234 }
235
236 /*
237  * Add memory segment to the segment list if it doesn't overlap with
238  * an already present segment.
239  */
240 static int insert_memory_segment(struct memory_segment *seg)
241 {
242         struct memory_segment *tmp;
243
244         if (seg->start + seg->size > VMEM_MAX_PHYS ||
245             seg->start + seg->size < seg->start)
246                 return -ERANGE;
247
248         list_for_each_entry(tmp, &mem_segs, list) {
249                 if (seg->start >= tmp->start + tmp->size)
250                         continue;
251                 if (seg->start + seg->size <= tmp->start)
252                         continue;
253                 return -ENOSPC;
254         }
255         list_add(&seg->list, &mem_segs);
256         return 0;
257 }
258
259 /*
260  * Remove memory segment from the segment list.
261  */
262 static void remove_memory_segment(struct memory_segment *seg)
263 {
264         list_del(&seg->list);
265 }
266
267 static void __remove_shared_memory(struct memory_segment *seg)
268 {
269         remove_memory_segment(seg);
270         vmem_remove_range(seg->start, seg->size);
271 }
272
273 int vmem_remove_mapping(unsigned long start, unsigned long size)
274 {
275         struct memory_segment *seg;
276         int ret;
277
278         mutex_lock(&vmem_mutex);
279
280         ret = -ENOENT;
281         list_for_each_entry(seg, &mem_segs, list) {
282                 if (seg->start == start && seg->size == size)
283                         break;
284         }
285
286         if (seg->start != start || seg->size != size)
287                 goto out;
288
289         ret = 0;
290         __remove_shared_memory(seg);
291         kfree(seg);
292 out:
293         mutex_unlock(&vmem_mutex);
294         return ret;
295 }
296
297 int vmem_add_mapping(unsigned long start, unsigned long size)
298 {
299         struct memory_segment *seg;
300         int ret;
301
302         mutex_lock(&vmem_mutex);
303         ret = -ENOMEM;
304         seg = kzalloc(sizeof(*seg), GFP_KERNEL);
305         if (!seg)
306                 goto out;
307         seg->start = start;
308         seg->size = size;
309
310         ret = insert_memory_segment(seg);
311         if (ret)
312                 goto out_free;
313
314         ret = vmem_add_mem(start, size, 0);
315         if (ret)
316                 goto out_remove;
317         goto out;
318
319 out_remove:
320         __remove_shared_memory(seg);
321 out_free:
322         kfree(seg);
323 out:
324         mutex_unlock(&vmem_mutex);
325         return ret;
326 }
327
328 /*
329  * map whole physical memory to virtual memory (identity mapping)
330  * we reserve enough space in the vmalloc area for vmemmap to hotplug
331  * additional memory segments.
332  */
333 void __init vmem_map_init(void)
334 {
335         unsigned long ro_start, ro_end;
336         unsigned long start, end;
337         int i;
338
339         spin_lock_init(&init_mm.context.list_lock);
340         INIT_LIST_HEAD(&init_mm.context.crst_list);
341         INIT_LIST_HEAD(&init_mm.context.pgtable_list);
342         init_mm.context.noexec = 0;
343         ro_start = ((unsigned long)&_stext) & PAGE_MASK;
344         ro_end = PFN_ALIGN((unsigned long)&_eshared);
345         for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
346                 start = memory_chunk[i].addr;
347                 end = memory_chunk[i].addr + memory_chunk[i].size;
348                 if (start >= ro_end || end <= ro_start)
349                         vmem_add_mem(start, end - start, 0);
350                 else if (start >= ro_start && end <= ro_end)
351                         vmem_add_mem(start, end - start, 1);
352                 else if (start >= ro_start) {
353                         vmem_add_mem(start, ro_end - start, 1);
354                         vmem_add_mem(ro_end, end - ro_end, 0);
355                 } else if (end < ro_end) {
356                         vmem_add_mem(start, ro_start - start, 0);
357                         vmem_add_mem(ro_start, end - ro_start, 1);
358                 } else {
359                         vmem_add_mem(start, ro_start - start, 0);
360                         vmem_add_mem(ro_start, ro_end - ro_start, 1);
361                         vmem_add_mem(ro_end, end - ro_end, 0);
362                 }
363         }
364 }
365
366 /*
367  * Convert memory chunk array to a memory segment list so there is a single
368  * list that contains both r/w memory and shared memory segments.
369  */
370 static int __init vmem_convert_memory_chunk(void)
371 {
372         struct memory_segment *seg;
373         int i;
374
375         mutex_lock(&vmem_mutex);
376         for (i = 0; i < MEMORY_CHUNKS; i++) {
377                 if (!memory_chunk[i].size)
378                         continue;
379                 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
380                 if (!seg)
381                         panic("Out of memory...\n");
382                 seg->start = memory_chunk[i].addr;
383                 seg->size = memory_chunk[i].size;
384                 insert_memory_segment(seg);
385         }
386         mutex_unlock(&vmem_mutex);
387         return 0;
388 }
389
390 core_initcall(vmem_convert_memory_chunk);