[PATCH] USB: MODALIAS change for bcdDevice
[linux-2.6] / mm / hugetlb.c
1 /*
2  * Generic hugetlb support.
3  * (C) William Irwin, April 2004
4  */
5 #include <linux/gfp.h>
6 #include <linux/list.h>
7 #include <linux/init.h>
8 #include <linux/module.h>
9 #include <linux/mm.h>
10 #include <linux/hugetlb.h>
11 #include <linux/sysctl.h>
12 #include <linux/highmem.h>
13 #include <linux/nodemask.h>
14
15 const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
16 static unsigned long nr_huge_pages, free_huge_pages;
17 unsigned long max_huge_pages;
18 static struct list_head hugepage_freelists[MAX_NUMNODES];
19 static unsigned int nr_huge_pages_node[MAX_NUMNODES];
20 static unsigned int free_huge_pages_node[MAX_NUMNODES];
21 static DEFINE_SPINLOCK(hugetlb_lock);
22
23 static void enqueue_huge_page(struct page *page)
24 {
25         int nid = page_to_nid(page);
26         list_add(&page->lru, &hugepage_freelists[nid]);
27         free_huge_pages++;
28         free_huge_pages_node[nid]++;
29 }
30
31 static struct page *dequeue_huge_page(void)
32 {
33         int nid = numa_node_id();
34         struct page *page = NULL;
35
36         if (list_empty(&hugepage_freelists[nid])) {
37                 for (nid = 0; nid < MAX_NUMNODES; ++nid)
38                         if (!list_empty(&hugepage_freelists[nid]))
39                                 break;
40         }
41         if (nid >= 0 && nid < MAX_NUMNODES &&
42             !list_empty(&hugepage_freelists[nid])) {
43                 page = list_entry(hugepage_freelists[nid].next,
44                                   struct page, lru);
45                 list_del(&page->lru);
46                 free_huge_pages--;
47                 free_huge_pages_node[nid]--;
48         }
49         return page;
50 }
51
52 static struct page *alloc_fresh_huge_page(void)
53 {
54         static int nid = 0;
55         struct page *page;
56         page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN,
57                                         HUGETLB_PAGE_ORDER);
58         nid = (nid + 1) % num_online_nodes();
59         if (page) {
60                 nr_huge_pages++;
61                 nr_huge_pages_node[page_to_nid(page)]++;
62         }
63         return page;
64 }
65
66 void free_huge_page(struct page *page)
67 {
68         BUG_ON(page_count(page));
69
70         INIT_LIST_HEAD(&page->lru);
71         page[1].mapping = NULL;
72
73         spin_lock(&hugetlb_lock);
74         enqueue_huge_page(page);
75         spin_unlock(&hugetlb_lock);
76 }
77
78 struct page *alloc_huge_page(void)
79 {
80         struct page *page;
81         int i;
82
83         spin_lock(&hugetlb_lock);
84         page = dequeue_huge_page();
85         if (!page) {
86                 spin_unlock(&hugetlb_lock);
87                 return NULL;
88         }
89         spin_unlock(&hugetlb_lock);
90         set_page_count(page, 1);
91         page[1].mapping = (void *)free_huge_page;
92         for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i)
93                 clear_highpage(&page[i]);
94         return page;
95 }
96
97 static int __init hugetlb_init(void)
98 {
99         unsigned long i;
100         struct page *page;
101
102         for (i = 0; i < MAX_NUMNODES; ++i)
103                 INIT_LIST_HEAD(&hugepage_freelists[i]);
104
105         for (i = 0; i < max_huge_pages; ++i) {
106                 page = alloc_fresh_huge_page();
107                 if (!page)
108                         break;
109                 spin_lock(&hugetlb_lock);
110                 enqueue_huge_page(page);
111                 spin_unlock(&hugetlb_lock);
112         }
113         max_huge_pages = free_huge_pages = nr_huge_pages = i;
114         printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages);
115         return 0;
116 }
117 module_init(hugetlb_init);
118
119 static int __init hugetlb_setup(char *s)
120 {
121         if (sscanf(s, "%lu", &max_huge_pages) <= 0)
122                 max_huge_pages = 0;
123         return 1;
124 }
125 __setup("hugepages=", hugetlb_setup);
126
127 #ifdef CONFIG_SYSCTL
128 static void update_and_free_page(struct page *page)
129 {
130         int i;
131         nr_huge_pages--;
132         nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--;
133         for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) {
134                 page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced |
135                                 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved |
136                                 1 << PG_private | 1<< PG_writeback);
137                 set_page_count(&page[i], 0);
138         }
139         set_page_count(page, 1);
140         __free_pages(page, HUGETLB_PAGE_ORDER);
141 }
142
143 #ifdef CONFIG_HIGHMEM
144 static void try_to_free_low(unsigned long count)
145 {
146         int i, nid;
147         for (i = 0; i < MAX_NUMNODES; ++i) {
148                 struct page *page, *next;
149                 list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) {
150                         if (PageHighMem(page))
151                                 continue;
152                         list_del(&page->lru);
153                         update_and_free_page(page);
154                         nid = page_zone(page)->zone_pgdat->node_id;
155                         free_huge_pages--;
156                         free_huge_pages_node[nid]--;
157                         if (count >= nr_huge_pages)
158                                 return;
159                 }
160         }
161 }
162 #else
163 static inline void try_to_free_low(unsigned long count)
164 {
165 }
166 #endif
167
168 static unsigned long set_max_huge_pages(unsigned long count)
169 {
170         while (count > nr_huge_pages) {
171                 struct page *page = alloc_fresh_huge_page();
172                 if (!page)
173                         return nr_huge_pages;
174                 spin_lock(&hugetlb_lock);
175                 enqueue_huge_page(page);
176                 spin_unlock(&hugetlb_lock);
177         }
178         if (count >= nr_huge_pages)
179                 return nr_huge_pages;
180
181         spin_lock(&hugetlb_lock);
182         try_to_free_low(count);
183         while (count < nr_huge_pages) {
184                 struct page *page = dequeue_huge_page();
185                 if (!page)
186                         break;
187                 update_and_free_page(page);
188         }
189         spin_unlock(&hugetlb_lock);
190         return nr_huge_pages;
191 }
192
193 int hugetlb_sysctl_handler(struct ctl_table *table, int write,
194                            struct file *file, void __user *buffer,
195                            size_t *length, loff_t *ppos)
196 {
197         proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
198         max_huge_pages = set_max_huge_pages(max_huge_pages);
199         return 0;
200 }
201 #endif /* CONFIG_SYSCTL */
202
203 int hugetlb_report_meminfo(char *buf)
204 {
205         return sprintf(buf,
206                         "HugePages_Total: %5lu\n"
207                         "HugePages_Free:  %5lu\n"
208                         "Hugepagesize:    %5lu kB\n",
209                         nr_huge_pages,
210                         free_huge_pages,
211                         HPAGE_SIZE/1024);
212 }
213
214 int hugetlb_report_node_meminfo(int nid, char *buf)
215 {
216         return sprintf(buf,
217                 "Node %d HugePages_Total: %5u\n"
218                 "Node %d HugePages_Free:  %5u\n",
219                 nid, nr_huge_pages_node[nid],
220                 nid, free_huge_pages_node[nid]);
221 }
222
223 int is_hugepage_mem_enough(size_t size)
224 {
225         return (size + ~HPAGE_MASK)/HPAGE_SIZE <= free_huge_pages;
226 }
227
228 /* Return the number pages of memory we physically have, in PAGE_SIZE units. */
229 unsigned long hugetlb_total_pages(void)
230 {
231         return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE);
232 }
233 EXPORT_SYMBOL(hugetlb_total_pages);
234
235 /*
236  * We cannot handle pagefaults against hugetlb pages at all.  They cause
237  * handle_mm_fault() to try to instantiate regular-sized pages in the
238  * hugegpage VMA.  do_page_fault() is supposed to trap this, so BUG is we get
239  * this far.
240  */
241 static struct page *hugetlb_nopage(struct vm_area_struct *vma,
242                                 unsigned long address, int *unused)
243 {
244         BUG();
245         return NULL;
246 }
247
248 struct vm_operations_struct hugetlb_vm_ops = {
249         .nopage = hugetlb_nopage,
250 };
251
252 void zap_hugepage_range(struct vm_area_struct *vma,
253                         unsigned long start, unsigned long length)
254 {
255         struct mm_struct *mm = vma->vm_mm;
256
257         spin_lock(&mm->page_table_lock);
258         unmap_hugepage_range(vma, start, start + length);
259         spin_unlock(&mm->page_table_lock);
260 }