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11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/string.h>
15#include <linux/mm.h>
16#include <linux/vmalloc.h>
17#include <linux/delay.h>
18#include <linux/interrupt.h>
19#include <linux/fb.h>
20#include <linux/list.h>
21
22
23#include <linux/rmap.h>
24#include <linux/pagemap.h>
25
26static struct page *fb_deferred_io_page(struct fb_info *info, unsigned long offs)
27{
28 void *screen_base = (void __force *) info->screen_base;
29 struct page *page;
30
31 if (is_vmalloc_addr(screen_base + offs))
32 page = vmalloc_to_page(screen_base + offs);
33 else
34 page = pfn_to_page((info->fix.smem_start + offs) >> PAGE_SHIFT);
35
36 return page;
37}
38
39
40static vm_fault_t fb_deferred_io_fault(struct vm_fault *vmf)
41{
42 unsigned long offset;
43 struct page *page;
44 struct fb_info *info = vmf->vma->vm_private_data;
45
46 offset = vmf->pgoff << PAGE_SHIFT;
47 if (offset >= info->fix.smem_len)
48 return VM_FAULT_SIGBUS;
49
50 page = fb_deferred_io_page(info, offset);
51 if (!page)
52 return VM_FAULT_SIGBUS;
53
54 get_page(page);
55
56 if (vmf->vma->vm_file)
57 page->mapping = vmf->vma->vm_file->f_mapping;
58 else
59 printk(KERN_ERR "no mapping available\n");
60
61 BUG_ON(!page->mapping);
62 page->index = vmf->pgoff;
63
64 vmf->page = page;
65 return 0;
66}
67
68int fb_deferred_io_fsync(struct file *file, loff_t start, loff_t end, int datasync)
69{
70 struct fb_info *info = file->private_data;
71 struct inode *inode = file_inode(file);
72 int err = file_write_and_wait_range(file, start, end);
73 if (err)
74 return err;
75
76
77 if (!info->fbdefio)
78 return 0;
79
80 inode_lock(inode);
81
82 cancel_delayed_work_sync(&info->deferred_work);
83
84
85 schedule_delayed_work(&info->deferred_work, 0);
86 inode_unlock(inode);
87
88 return 0;
89}
90EXPORT_SYMBOL_GPL(fb_deferred_io_fsync);
91
92
93static vm_fault_t fb_deferred_io_mkwrite(struct vm_fault *vmf)
94{
95 struct page *page = vmf->page;
96 struct fb_info *info = vmf->vma->vm_private_data;
97 struct fb_deferred_io *fbdefio = info->fbdefio;
98 struct page *cur;
99
100
101
102
103
104
105
106 file_update_time(vmf->vma->vm_file);
107
108
109 mutex_lock(&fbdefio->lock);
110
111
112 if (fbdefio->first_io && list_empty(&fbdefio->pagelist))
113 fbdefio->first_io(info);
114
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118
119
120
121
122
123 lock_page(page);
124
125
126
127 list_for_each_entry(cur, &fbdefio->pagelist, lru) {
128
129
130
131
132
133 if (unlikely(cur == page))
134 goto page_already_added;
135 else if (cur->index > page->index)
136 break;
137 }
138
139 list_add_tail(&page->lru, &cur->lru);
140
141page_already_added:
142 mutex_unlock(&fbdefio->lock);
143
144
145 schedule_delayed_work(&info->deferred_work, fbdefio->delay);
146 return VM_FAULT_LOCKED;
147}
148
149static const struct vm_operations_struct fb_deferred_io_vm_ops = {
150 .fault = fb_deferred_io_fault,
151 .page_mkwrite = fb_deferred_io_mkwrite,
152};
153
154static int fb_deferred_io_set_page_dirty(struct page *page)
155{
156 if (!PageDirty(page))
157 SetPageDirty(page);
158 return 0;
159}
160
161static const struct address_space_operations fb_deferred_io_aops = {
162 .set_page_dirty = fb_deferred_io_set_page_dirty,
163};
164
165int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma)
166{
167 vma->vm_ops = &fb_deferred_io_vm_ops;
168 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
169 if (!(info->flags & FBINFO_VIRTFB))
170 vma->vm_flags |= VM_IO;
171 vma->vm_private_data = info;
172 return 0;
173}
174
175
176static void fb_deferred_io_work(struct work_struct *work)
177{
178 struct fb_info *info = container_of(work, struct fb_info,
179 deferred_work.work);
180 struct list_head *node, *next;
181 struct page *cur;
182 struct fb_deferred_io *fbdefio = info->fbdefio;
183
184
185 mutex_lock(&fbdefio->lock);
186 list_for_each_entry(cur, &fbdefio->pagelist, lru) {
187 lock_page(cur);
188 page_mkclean(cur);
189 unlock_page(cur);
190 }
191
192
193 fbdefio->deferred_io(info, &fbdefio->pagelist);
194
195
196 list_for_each_safe(node, next, &fbdefio->pagelist) {
197 list_del(node);
198 }
199 mutex_unlock(&fbdefio->lock);
200}
201
202void fb_deferred_io_init(struct fb_info *info)
203{
204 struct fb_deferred_io *fbdefio = info->fbdefio;
205
206 BUG_ON(!fbdefio);
207 mutex_init(&fbdefio->lock);
208 INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work);
209 INIT_LIST_HEAD(&fbdefio->pagelist);
210 if (fbdefio->delay == 0)
211 fbdefio->delay = HZ;
212}
213EXPORT_SYMBOL_GPL(fb_deferred_io_init);
214
215void fb_deferred_io_open(struct fb_info *info,
216 struct inode *inode,
217 struct file *file)
218{
219 file->f_mapping->a_ops = &fb_deferred_io_aops;
220}
221EXPORT_SYMBOL_GPL(fb_deferred_io_open);
222
223void fb_deferred_io_cleanup(struct fb_info *info)
224{
225 struct fb_deferred_io *fbdefio = info->fbdefio;
226 struct page *page;
227 int i;
228
229 BUG_ON(!fbdefio);
230 cancel_delayed_work_sync(&info->deferred_work);
231
232
233 for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) {
234 page = fb_deferred_io_page(info, i);
235 page->mapping = NULL;
236 }
237
238 mutex_destroy(&fbdefio->lock);
239}
240EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
241