summaryrefslogtreecommitdiff
path: root/drivers/video/fbdev/core/fb_chrdev.c
blob: 32a7315b4b6dd32147414643170006bd6fc8a759 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
// SPDX-License-Identifier: GPL-2.0

#include <linux/compat.h>
#include <linux/console.h>
#include <linux/fb.h>
#include <linux/fbcon.h>
#include <linux/major.h>

#include "fb_internal.h"

/*
 * We hold a reference to the fb_info in file->private_data,
 * but if the current registered fb has changed, we don't
 * actually want to use it.
 *
 * So look up the fb_info using the inode minor number,
 * and just verify it against the reference we have.
 */
static struct fb_info *file_fb_info(struct file *file)
{
	struct inode *inode = file_inode(file);
	int fbidx = iminor(inode);
	struct fb_info *info = registered_fb[fbidx];

	if (info != file->private_data)
		info = NULL;
	return info;
}

static ssize_t fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	struct fb_info *info = file_fb_info(file);

	if (!info)
		return -ENODEV;

	if (info->state != FBINFO_STATE_RUNNING)
		return -EPERM;

	if (info->fbops->fb_read)
		return info->fbops->fb_read(info, buf, count, ppos);

	return fb_io_read(info, buf, count, ppos);
}

static ssize_t fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
	struct fb_info *info = file_fb_info(file);

	if (!info)
		return -ENODEV;

	if (info->state != FBINFO_STATE_RUNNING)
		return -EPERM;

	if (info->fbops->fb_write)
		return info->fbops->fb_write(info, buf, count, ppos);

	return fb_io_write(info, buf, count, ppos);
}

static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
			unsigned long arg)
{
	const struct fb_ops *fb;
	struct fb_var_screeninfo var;
	struct fb_fix_screeninfo fix;
	struct fb_cmap cmap_from;
	struct fb_cmap_user cmap;
	void __user *argp = (void __user *)arg;
	long ret = 0;

	switch (cmd) {
	case FBIOGET_VSCREENINFO:
		lock_fb_info(info);
		var = info->var;
		unlock_fb_info(info);

		ret = copy_to_user(argp, &var, sizeof(var)) ? -EFAULT : 0;
		break;
	case FBIOPUT_VSCREENINFO:
		if (copy_from_user(&var, argp, sizeof(var)))
			return -EFAULT;
		/* only for kernel-internal use */
		var.activate &= ~FB_ACTIVATE_KD_TEXT;
		console_lock();
		lock_fb_info(info);
		ret = fbcon_modechange_possible(info, &var);
		if (!ret)
			ret = fb_set_var(info, &var);
		if (!ret)
			fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
		unlock_fb_info(info);
		console_unlock();
		if (!ret && copy_to_user(argp, &var, sizeof(var)))
			ret = -EFAULT;
		break;
	case FBIOGET_FSCREENINFO:
		lock_fb_info(info);
		memcpy(&fix, &info->fix, sizeof(fix));
		if (info->flags & FBINFO_HIDE_SMEM_START)
			fix.smem_start = 0;
		unlock_fb_info(info);

		ret = copy_to_user(argp, &fix, sizeof(fix)) ? -EFAULT : 0;
		break;
	case FBIOPUTCMAP:
		if (copy_from_user(&cmap, argp, sizeof(cmap)))
			return -EFAULT;
		ret = fb_set_user_cmap(&cmap, info);
		break;
	case FBIOGETCMAP:
		if (copy_from_user(&cmap, argp, sizeof(cmap)))
			return -EFAULT;
		lock_fb_info(info);
		cmap_from = info->cmap;
		unlock_fb_info(info);
		ret = fb_cmap_to_user(&cmap_from, &cmap);
		break;
	case FBIOPAN_DISPLAY:
		if (copy_from_user(&var, argp, sizeof(var)))
			return -EFAULT;
		console_lock();
		lock_fb_info(info);
		ret = fb_pan_display(info, &var);
		unlock_fb_info(info);
		console_unlock();
		if (ret == 0 && copy_to_user(argp, &var, sizeof(var)))
			return -EFAULT;
		break;
	case FBIO_CURSOR:
		ret = -EINVAL;
		break;
	case FBIOGET_CON2FBMAP:
		ret = fbcon_get_con2fb_map_ioctl(argp);
		break;
	case FBIOPUT_CON2FBMAP:
		ret = fbcon_set_con2fb_map_ioctl(argp);
		break;
	case FBIOBLANK:
		if (arg > FB_BLANK_POWERDOWN)
			return -EINVAL;
		console_lock();
		lock_fb_info(info);
		ret = fb_blank(info, arg);
		/* might again call into fb_blank */
		fbcon_fb_blanked(info, arg);
		unlock_fb_info(info);
		console_unlock();
		break;
	default:
		lock_fb_info(info);
		fb = info->fbops;
		if (fb->fb_ioctl)
			ret = fb->fb_ioctl(info, cmd, arg);
		else
			ret = -ENOTTY;
		unlock_fb_info(info);
	}
	return ret;
}

static long fb_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct fb_info *info = file_fb_info(file);

	if (!info)
		return -ENODEV;
	return do_fb_ioctl(info, cmd, arg);
}

#ifdef CONFIG_COMPAT
struct fb_fix_screeninfo32 {
	char			id[16];
	compat_caddr_t		smem_start;
	u32			smem_len;
	u32			type;
	u32			type_aux;
	u32			visual;
	u16			xpanstep;
	u16			ypanstep;
	u16			ywrapstep;
	u32			line_length;
	compat_caddr_t		mmio_start;
	u32			mmio_len;
	u32			accel;
	u16			reserved[3];
};

struct fb_cmap32 {
	u32			start;
	u32			len;
	compat_caddr_t	red;
	compat_caddr_t	green;
	compat_caddr_t	blue;
	compat_caddr_t	transp;
};

static int fb_getput_cmap(struct fb_info *info, unsigned int cmd,
			  unsigned long arg)
{
	struct fb_cmap32 cmap32;
	struct fb_cmap cmap_from;
	struct fb_cmap_user cmap;

	if (copy_from_user(&cmap32, compat_ptr(arg), sizeof(cmap32)))
		return -EFAULT;

	cmap = (struct fb_cmap_user) {
		.start	= cmap32.start,
		.len	= cmap32.len,
		.red	= compat_ptr(cmap32.red),
		.green	= compat_ptr(cmap32.green),
		.blue	= compat_ptr(cmap32.blue),
		.transp	= compat_ptr(cmap32.transp),
	};

	if (cmd == FBIOPUTCMAP)
		return fb_set_user_cmap(&cmap, info);

	lock_fb_info(info);
	cmap_from = info->cmap;
	unlock_fb_info(info);

	return fb_cmap_to_user(&cmap_from, &cmap);
}

static int do_fscreeninfo_to_user(struct fb_fix_screeninfo *fix,
				  struct fb_fix_screeninfo32 __user *fix32)
{
	__u32 data;
	int err;

	err = copy_to_user(&fix32->id, &fix->id, sizeof(fix32->id));

	data = (__u32) (unsigned long) fix->smem_start;
	err |= put_user(data, &fix32->smem_start);

	err |= put_user(fix->smem_len, &fix32->smem_len);
	err |= put_user(fix->type, &fix32->type);
	err |= put_user(fix->type_aux, &fix32->type_aux);
	err |= put_user(fix->visual, &fix32->visual);
	err |= put_user(fix->xpanstep, &fix32->xpanstep);
	err |= put_user(fix->ypanstep, &fix32->ypanstep);
	err |= put_user(fix->ywrapstep, &fix32->ywrapstep);
	err |= put_user(fix->line_length, &fix32->line_length);

	data = (__u32) (unsigned long) fix->mmio_start;
	err |= put_user(data, &fix32->mmio_start);

	err |= put_user(fix->mmio_len, &fix32->mmio_len);
	err |= put_user(fix->accel, &fix32->accel);
	err |= copy_to_user(fix32->reserved, fix->reserved,
			    sizeof(fix->reserved));

	if (err)
		return -EFAULT;
	return 0;
}

static int fb_get_fscreeninfo(struct fb_info *info, unsigned int cmd,
			      unsigned long arg)
{
	struct fb_fix_screeninfo fix;

	lock_fb_info(info);
	fix = info->fix;
	if (info->flags & FBINFO_HIDE_SMEM_START)
		fix.smem_start = 0;
	unlock_fb_info(info);
	return do_fscreeninfo_to_user(&fix, compat_ptr(arg));
}

static long fb_compat_ioctl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
	struct fb_info *info = file_fb_info(file);
	const struct fb_ops *fb;
	long ret = -ENOIOCTLCMD;

	if (!info)
		return -ENODEV;
	fb = info->fbops;
	switch (cmd) {
	case FBIOGET_VSCREENINFO:
	case FBIOPUT_VSCREENINFO:
	case FBIOPAN_DISPLAY:
	case FBIOGET_CON2FBMAP:
	case FBIOPUT_CON2FBMAP:
		arg = (unsigned long) compat_ptr(arg);
		fallthrough;
	case FBIOBLANK:
		ret = do_fb_ioctl(info, cmd, arg);
		break;

	case FBIOGET_FSCREENINFO:
		ret = fb_get_fscreeninfo(info, cmd, arg);
		break;

	case FBIOGETCMAP:
	case FBIOPUTCMAP:
		ret = fb_getput_cmap(info, cmd, arg);
		break;

	default:
		if (fb->fb_compat_ioctl)
			ret = fb->fb_compat_ioctl(info, cmd, arg);
		break;
	}
	return ret;
}
#endif

static int fb_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct fb_info *info = file_fb_info(file);
	unsigned long mmio_pgoff;
	unsigned long start;
	u32 len;

	if (!info)
		return -ENODEV;
	mutex_lock(&info->mm_lock);

	if (info->fbops->fb_mmap) {
		int res;

		/*
		 * The framebuffer needs to be accessed decrypted, be sure
		 * SME protection is removed ahead of the call
		 */
		vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
		res = info->fbops->fb_mmap(info, vma);
		mutex_unlock(&info->mm_lock);
		return res;
#if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
	} else if (info->fbdefio) {
		/*
		 * FB deferred I/O wants you to handle mmap in your drivers. At a
		 * minimum, point struct fb_ops.fb_mmap to fb_deferred_io_mmap().
		 */
		dev_warn_once(info->dev, "fbdev mmap not set up for deferred I/O.\n");
		mutex_unlock(&info->mm_lock);
		return -ENODEV;
#endif
	}

	/*
	 * Ugh. This can be either the frame buffer mapping, or
	 * if pgoff points past it, the mmio mapping.
	 */
	start = info->fix.smem_start;
	len = info->fix.smem_len;
	mmio_pgoff = PAGE_ALIGN((start & ~PAGE_MASK) + len) >> PAGE_SHIFT;
	if (vma->vm_pgoff >= mmio_pgoff) {
		if (info->var.accel_flags) {
			mutex_unlock(&info->mm_lock);
			return -EINVAL;
		}

		vma->vm_pgoff -= mmio_pgoff;
		start = info->fix.mmio_start;
		len = info->fix.mmio_len;
	}
	mutex_unlock(&info->mm_lock);

	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
	vma->vm_page_prot = pgprot_framebuffer(vma->vm_page_prot, vma->vm_start,
					       vma->vm_end, start);

	return vm_iomap_memory(vma, start, len);
}

static int fb_open(struct inode *inode, struct file *file)
__acquires(&info->lock)
__releases(&info->lock)
{
	int fbidx = iminor(inode);
	struct fb_info *info;
	int res = 0;

	info = get_fb_info(fbidx);
	if (!info) {
		request_module("fb%d", fbidx);
		info = get_fb_info(fbidx);
		if (!info)
			return -ENODEV;
	}
	if (IS_ERR(info))
		return PTR_ERR(info);

	lock_fb_info(info);
	if (!try_module_get(info->fbops->owner)) {
		res = -ENODEV;
		goto out;
	}
	file->private_data = info;
	if (info->fbops->fb_open) {
		res = info->fbops->fb_open(info, 1);
		if (res)
			module_put(info->fbops->owner);
	}
#ifdef CONFIG_FB_DEFERRED_IO
	if (info->fbdefio)
		fb_deferred_io_open(info, inode, file);
#endif
out:
	unlock_fb_info(info);
	if (res)
		put_fb_info(info);
	return res;
}

static int fb_release(struct inode *inode, struct file *file)
__acquires(&info->lock)
__releases(&info->lock)
{
	struct fb_info * const info = file->private_data;

	lock_fb_info(info);
#if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
	if (info->fbdefio)
		fb_deferred_io_release(info);
#endif
	if (info->fbops->fb_release)
		info->fbops->fb_release(info, 1);
	module_put(info->fbops->owner);
	unlock_fb_info(info);
	put_fb_info(info);
	return 0;
}

#if defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && !defined(CONFIG_MMU)
static unsigned long get_fb_unmapped_area(struct file *filp,
				   unsigned long addr, unsigned long len,
				   unsigned long pgoff, unsigned long flags)
{
	struct fb_info * const info = filp->private_data;
	unsigned long fb_size = PAGE_ALIGN(info->fix.smem_len);

	if (pgoff > fb_size || len > fb_size - pgoff)
		return -EINVAL;

	return (unsigned long)info->screen_base + pgoff;
}
#endif

static const struct file_operations fb_fops = {
	.owner = THIS_MODULE,
	.read = fb_read,
	.write = fb_write,
	.unlocked_ioctl = fb_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = fb_compat_ioctl,
#endif
	.mmap = fb_mmap,
	.open = fb_open,
	.release = fb_release,
#if defined(HAVE_ARCH_FB_UNMAPPED_AREA) || \
	(defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && \
	 !defined(CONFIG_MMU))
	.get_unmapped_area = get_fb_unmapped_area,
#endif
#ifdef CONFIG_FB_DEFERRED_IO
	.fsync = fb_deferred_io_fsync,
#endif
	.llseek = default_llseek,
};

int fb_register_chrdev(void)
{
	int ret;

	ret = register_chrdev(FB_MAJOR, "fb", &fb_fops);
	if (ret) {
		pr_err("Unable to get major %d for fb devs\n", FB_MAJOR);
		return ret;
	}

	return ret;
}

void fb_unregister_chrdev(void)
{
	unregister_chrdev(FB_MAJOR, "fb");
}