1// SPDX-License-Identifier: MIT
2
3#include <linux/export.h>
4#include <linux/fb.h>
5#include <linux/vmalloc.h>
6
7#include <drm/drm_drv.h>
8#include <drm/drm_fbdev_dma.h>
9#include <drm/drm_fb_dma_helper.h>
10#include <drm/drm_fb_helper.h>
11#include <drm/drm_framebuffer.h>
12#include <drm/drm_gem_dma_helper.h>
13#include <drm/drm_print.h>
14
15/*
16 * struct fb_ops
17 */
18
19static int drm_fbdev_dma_fb_open(struct fb_info *info, int user)
20{
21 struct drm_fb_helper *fb_helper = info->par;
22
23 /* No need to take a ref for fbcon because it unbinds on unregister */
24 if (user && !try_module_get(module: fb_helper->dev->driver->fops->owner))
25 return -ENODEV;
26
27 return 0;
28}
29
30static int drm_fbdev_dma_fb_release(struct fb_info *info, int user)
31{
32 struct drm_fb_helper *fb_helper = info->par;
33
34 if (user)
35 module_put(module: fb_helper->dev->driver->fops->owner);
36
37 return 0;
38}
39
40static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
41{
42 struct drm_fb_helper *fb_helper = info->par;
43
44 return drm_gem_prime_mmap(obj: fb_helper->buffer->gem, vma);
45}
46
47static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
48{
49 struct drm_fb_helper *fb_helper = info->par;
50
51 if (!fb_helper->dev)
52 return;
53
54 if (info->fbdefio)
55 fb_deferred_io_cleanup(info);
56 drm_fb_helper_fini(helper: fb_helper);
57
58 drm_client_buffer_vunmap(buffer: fb_helper->buffer);
59 drm_client_buffer_delete(buffer: fb_helper->buffer);
60 drm_client_release(client: &fb_helper->client);
61}
62
63static const struct fb_ops drm_fbdev_dma_fb_ops = {
64 .owner = THIS_MODULE,
65 .fb_open = drm_fbdev_dma_fb_open,
66 .fb_release = drm_fbdev_dma_fb_release,
67 __FB_DEFAULT_DMAMEM_OPS_RDWR,
68 DRM_FB_HELPER_DEFAULT_OPS,
69 __FB_DEFAULT_DMAMEM_OPS_DRAW,
70 .fb_mmap = drm_fbdev_dma_fb_mmap,
71 .fb_destroy = drm_fbdev_dma_fb_destroy,
72};
73
74FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma_shadowed,
75 drm_fb_helper_damage_range,
76 drm_fb_helper_damage_area);
77
78static void drm_fbdev_dma_shadowed_fb_destroy(struct fb_info *info)
79{
80 struct drm_fb_helper *fb_helper = info->par;
81 void *shadow = info->screen_buffer;
82
83 if (!fb_helper->dev)
84 return;
85
86 if (info->fbdefio)
87 fb_deferred_io_cleanup(info);
88 drm_fb_helper_fini(helper: fb_helper);
89 vfree(addr: shadow);
90
91 drm_client_buffer_vunmap(buffer: fb_helper->buffer);
92 drm_client_buffer_delete(buffer: fb_helper->buffer);
93 drm_client_release(client: &fb_helper->client);
94}
95
96static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
97 .owner = THIS_MODULE,
98 .fb_open = drm_fbdev_dma_fb_open,
99 .fb_release = drm_fbdev_dma_fb_release,
100 FB_DEFAULT_DEFERRED_OPS(drm_fbdev_dma_shadowed),
101 DRM_FB_HELPER_DEFAULT_OPS,
102 .fb_destroy = drm_fbdev_dma_shadowed_fb_destroy,
103};
104
105/*
106 * struct drm_fb_helper
107 */
108
109static void drm_fbdev_dma_damage_blit_real(struct drm_fb_helper *fb_helper,
110 struct drm_clip_rect *clip,
111 struct iosys_map *dst)
112{
113 struct drm_framebuffer *fb = fb_helper->fb;
114 size_t offset = clip->y1 * fb->pitches[0];
115 size_t len = clip->x2 - clip->x1;
116 unsigned int y;
117 void *src;
118
119 switch (drm_format_info_bpp(info: fb->format, plane: 0)) {
120 case 1:
121 offset += clip->x1 / 8;
122 len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
123 break;
124 case 2:
125 offset += clip->x1 / 4;
126 len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
127 break;
128 case 4:
129 offset += clip->x1 / 2;
130 len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
131 break;
132 default:
133 offset += clip->x1 * fb->format->cpp[0];
134 len *= fb->format->cpp[0];
135 break;
136 }
137
138 src = fb_helper->info->screen_buffer + offset;
139 iosys_map_incr(map: dst, incr: offset); /* go to first pixel within clip rect */
140
141 for (y = clip->y1; y < clip->y2; y++) {
142 iosys_map_memcpy_to(dst, dst_offset: 0, src, len);
143 iosys_map_incr(map: dst, incr: fb->pitches[0]);
144 src += fb->pitches[0];
145 }
146}
147
148static int drm_fbdev_dma_damage_blit(struct drm_fb_helper *fb_helper,
149 struct drm_clip_rect *clip)
150{
151 struct drm_client_buffer *buffer = fb_helper->buffer;
152 struct iosys_map dst;
153
154 /*
155 * For fbdev emulation, we only have to protect against fbdev modeset
156 * operations. Nothing else will involve the client buffer's BO. So it
157 * is sufficient to acquire struct drm_fb_helper.lock here.
158 */
159 mutex_lock(&fb_helper->lock);
160
161 dst = buffer->map;
162 drm_fbdev_dma_damage_blit_real(fb_helper, clip, dst: &dst);
163
164 mutex_unlock(lock: &fb_helper->lock);
165
166 return 0;
167}
168static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper,
169 struct drm_clip_rect *clip)
170{
171 struct drm_device *dev = helper->dev;
172 int ret;
173
174 /* Call damage handlers only if necessary */
175 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
176 return 0;
177
178 if (helper->fb->funcs->dirty) {
179 ret = drm_fbdev_dma_damage_blit(fb_helper: helper, clip);
180 if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
181 return ret;
182
183 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
184 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
185 return ret;
186 }
187
188 return 0;
189}
190
191static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {
192 .fb_dirty = drm_fbdev_dma_helper_fb_dirty,
193};
194
195/*
196 * struct drm_fb_helper
197 */
198
199static int drm_fbdev_dma_driver_fbdev_probe_tail(struct drm_fb_helper *fb_helper,
200 struct drm_fb_helper_surface_size *sizes)
201{
202 struct drm_device *dev = fb_helper->dev;
203 struct drm_client_buffer *buffer = fb_helper->buffer;
204 struct drm_gem_dma_object *dma_obj = to_drm_gem_dma_obj(buffer->gem);
205 struct drm_framebuffer *fb = fb_helper->fb;
206 struct fb_info *info = fb_helper->info;
207 struct iosys_map map = buffer->map;
208
209 info->fbops = &drm_fbdev_dma_fb_ops;
210
211 /* screen */
212 info->flags |= FBINFO_VIRTFB; /* system memory */
213 if (dma_obj->map_noncoherent)
214 info->flags |= FBINFO_READS_FAST; /* signal caching */
215 info->screen_size = sizes->surface_height * fb->pitches[0];
216 info->screen_buffer = map.vaddr;
217 if (!(info->flags & FBINFO_HIDE_SMEM_START)) {
218 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer)))
219 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
220 }
221 info->fix.smem_len = info->screen_size;
222
223 return 0;
224}
225
226static int drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(struct drm_fb_helper *fb_helper,
227 struct drm_fb_helper_surface_size *sizes)
228{
229 struct drm_client_buffer *buffer = fb_helper->buffer;
230 struct fb_info *info = fb_helper->info;
231 size_t screen_size = buffer->gem->size;
232 void *screen_buffer;
233 int ret;
234
235 /*
236 * Deferred I/O requires struct page for framebuffer memory,
237 * which is not guaranteed for all DMA ranges. We thus create
238 * a shadow buffer in system memory.
239 */
240 screen_buffer = vzalloc(screen_size);
241 if (!screen_buffer)
242 return -ENOMEM;
243
244 info->fbops = &drm_fbdev_dma_shadowed_fb_ops;
245
246 /* screen */
247 info->flags |= FBINFO_VIRTFB; /* system memory */
248 info->flags |= FBINFO_READS_FAST; /* signal caching */
249 info->screen_buffer = screen_buffer;
250 info->fix.smem_len = screen_size;
251
252 fb_helper->fbdefio.delay = HZ / 20;
253 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
254
255 info->fbdefio = &fb_helper->fbdefio;
256 ret = fb_deferred_io_init(info);
257 if (ret)
258 goto err_vfree;
259
260 return 0;
261
262err_vfree:
263 vfree(addr: screen_buffer);
264 return ret;
265}
266
267int drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
268 struct drm_fb_helper_surface_size *sizes)
269{
270 struct drm_client_dev *client = &fb_helper->client;
271 struct drm_device *dev = fb_helper->dev;
272 struct fb_info *info = fb_helper->info;
273 struct drm_client_buffer *buffer;
274 struct drm_framebuffer *fb;
275 u32 format;
276 struct iosys_map map;
277 int ret;
278
279 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
280 sizes->surface_width, sizes->surface_height,
281 sizes->surface_bpp);
282
283 format = drm_driver_legacy_fb_format(dev, bpp: sizes->surface_bpp,
284 depth: sizes->surface_depth);
285 buffer = drm_client_buffer_create_dumb(client, width: sizes->surface_width,
286 height: sizes->surface_height, format);
287 if (IS_ERR(ptr: buffer))
288 return PTR_ERR(ptr: buffer);
289
290 fb = buffer->fb;
291
292 ret = drm_client_buffer_vmap(buffer, map: &map);
293 if (ret) {
294 goto err_drm_client_buffer_delete;
295 } else if (drm_WARN_ON(dev, map.is_iomem)) {
296 ret = -ENODEV; /* I/O memory not supported; use generic emulation */
297 goto err_drm_client_buffer_delete;
298 }
299
300 fb_helper->funcs = &drm_fbdev_dma_helper_funcs;
301 fb_helper->buffer = buffer;
302 fb_helper->fb = fb;
303
304 drm_fb_helper_fill_info(info, fb_helper, sizes);
305
306 if (fb->funcs->dirty)
307 ret = drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(fb_helper, sizes);
308 else
309 ret = drm_fbdev_dma_driver_fbdev_probe_tail(fb_helper, sizes);
310 if (ret)
311 goto err_drm_client_buffer_vunmap;
312
313 return 0;
314
315err_drm_client_buffer_vunmap:
316 fb_helper->fb = NULL;
317 fb_helper->buffer = NULL;
318 drm_client_buffer_vunmap(buffer);
319err_drm_client_buffer_delete:
320 drm_client_buffer_delete(buffer);
321 return ret;
322}
323EXPORT_SYMBOL(drm_fbdev_dma_driver_fbdev_probe);
324

source code of linux/drivers/gpu/drm/drm_fbdev_dma.c