1 // SPDX-License-Identifier: GPL-2.0-only
2
3 #include <linux/export.h>
4 #include <linux/limits.h>
5 #include <linux/math64.h>
6 #include <linux/minmax.h>
7 #include <linux/screen_info.h>
8
9 #include <drm/drm_fourcc.h>
10 #include <drm/drm_print.h>
11
12 #include "drm_sysfb_helper.h"
13
drm_sysfb_get_validated_size0(struct drm_device * dev,const char * name,u64 value,u64 max)14 static s64 drm_sysfb_get_validated_size0(struct drm_device *dev, const char *name,
15 u64 value, u64 max)
16 {
17 if (!value) {
18 drm_warn(dev, "%s of 0 not allowed\n", name);
19 return -EINVAL;
20 } else if (value > min(max, S64_MAX)) {
21 drm_warn(dev, "%s of %llu exceeds maximum of %llu\n", name, value, max);
22 return -EINVAL;
23 }
24 return value;
25 }
26
drm_sysfb_get_width_si(struct drm_device * dev,const struct screen_info * si)27 int drm_sysfb_get_width_si(struct drm_device *dev, const struct screen_info *si)
28 {
29 return drm_sysfb_get_validated_int0(dev, "width", si->lfb_width, U16_MAX);
30 }
31 EXPORT_SYMBOL(drm_sysfb_get_width_si);
32
drm_sysfb_get_height_si(struct drm_device * dev,const struct screen_info * si)33 int drm_sysfb_get_height_si(struct drm_device *dev, const struct screen_info *si)
34 {
35 return drm_sysfb_get_validated_int0(dev, "height", si->lfb_height, U16_MAX);
36 }
37 EXPORT_SYMBOL(drm_sysfb_get_height_si);
38
drm_sysfb_get_memory_si(struct drm_device * dev,const struct screen_info * si,struct resource * res)39 struct resource *drm_sysfb_get_memory_si(struct drm_device *dev,
40 const struct screen_info *si,
41 struct resource *res)
42 {
43 ssize_t num;
44
45 num = screen_info_resources(si, res, 1);
46 if (!num) {
47 drm_warn(dev, "memory resource not found\n");
48 return NULL;
49 }
50
51 return res;
52 }
53 EXPORT_SYMBOL(drm_sysfb_get_memory_si);
54
drm_sysfb_get_stride_si(struct drm_device * dev,const struct screen_info * si,const struct drm_format_info * format,unsigned int width,unsigned int height,u64 size)55 int drm_sysfb_get_stride_si(struct drm_device *dev, const struct screen_info *si,
56 const struct drm_format_info *format,
57 unsigned int width, unsigned int height, u64 size)
58 {
59 u64 lfb_linelength = si->lfb_linelength;
60 s64 stride;
61
62 if (!lfb_linelength)
63 lfb_linelength = drm_format_info_min_pitch(format, 0, width);
64
65 stride = drm_sysfb_get_validated_size0(dev, "stride", lfb_linelength,
66 div64_u64(size, height));
67 if (stride < INT_MIN || stride > INT_MAX)
68 return -EINVAL;
69
70 return (int)stride; /* stride or negative errno code */
71 }
72 EXPORT_SYMBOL(drm_sysfb_get_stride_si);
73
drm_sysfb_get_visible_size_si(struct drm_device * dev,const struct screen_info * si,unsigned int height,unsigned int stride,u64 size)74 s64 drm_sysfb_get_visible_size_si(struct drm_device *dev, const struct screen_info *si,
75 unsigned int height, unsigned int stride, u64 size)
76 {
77 u64 vsize = mul_u32_u32(height, stride);
78
79 return drm_sysfb_get_validated_size0(dev, "visible size", vsize, size);
80 }
81 EXPORT_SYMBOL(drm_sysfb_get_visible_size_si);
82