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1// SPDX-License-Identifier: MIT
2
3#include <linux/fb.h>
4#include <linux/vmalloc.h>
5
6#include <drm/drm_drv.h>
7#include <drm/drm_fbdev_dma.h>
8#include <drm/drm_fb_dma_helper.h>
9#include <drm/drm_fb_helper.h>
10#include <drm/drm_framebuffer.h>
11#include <drm/drm_gem_dma_helper.h>
12
13/*
14 * struct fb_ops
15 */
16
17static int drm_fbdev_dma_fb_open(struct fb_info *info, int user)
18{
19 struct drm_fb_helper *fb_helper = info->par;
20
21 /* No need to take a ref for fbcon because it unbinds on unregister */
22 if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
23 return -ENODEV;
24
25 return 0;
26}
27
28static int drm_fbdev_dma_fb_release(struct fb_info *info, int user)
29{
30 struct drm_fb_helper *fb_helper = info->par;
31
32 if (user)
33 module_put(fb_helper->dev->driver->fops->owner);
34
35 return 0;
36}
37
38static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
39{
40 struct drm_fb_helper *fb_helper = info->par;
41
42 return drm_gem_prime_mmap(fb_helper->buffer->gem, vma);
43}
44
45static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
46{
47 struct drm_fb_helper *fb_helper = info->par;
48
49 if (!fb_helper->dev)
50 return;
51
52 if (info->fbdefio)
53 fb_deferred_io_cleanup(info);
54 drm_fb_helper_fini(fb_helper);
55
56 drm_client_buffer_vunmap(fb_helper->buffer);
57 drm_client_framebuffer_delete(fb_helper->buffer);
58 drm_client_release(&fb_helper->client);
59 drm_fb_helper_unprepare(fb_helper);
60 kfree(fb_helper);
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(fb_helper);
89 vfree(shadow);
90
91 drm_client_buffer_vunmap(fb_helper->buffer);
92 drm_client_framebuffer_delete(fb_helper->buffer);
93 drm_client_release(&fb_helper->client);
94 drm_fb_helper_unprepare(fb_helper);
95 kfree(fb_helper);
96}
97
98static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
99 .owner = THIS_MODULE,
100 .fb_open = drm_fbdev_dma_fb_open,
101 .fb_release = drm_fbdev_dma_fb_release,
102 FB_DEFAULT_DEFERRED_OPS(drm_fbdev_dma_shadowed),
103 DRM_FB_HELPER_DEFAULT_OPS,
104 .fb_destroy = drm_fbdev_dma_shadowed_fb_destroy,
105};
106
107/*
108 * struct drm_fb_helper
109 */
110
111static void drm_fbdev_dma_damage_blit_real(struct drm_fb_helper *fb_helper,
112 struct drm_clip_rect *clip,
113 struct iosys_map *dst)
114{
115 struct drm_framebuffer *fb = fb_helper->fb;
116 size_t offset = clip->y1 * fb->pitches[0];
117 size_t len = clip->x2 - clip->x1;
118 unsigned int y;
119 void *src;
120
121 switch (drm_format_info_bpp(fb->format, 0)) {
122 case 1:
123 offset += clip->x1 / 8;
124 len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
125 break;
126 case 2:
127 offset += clip->x1 / 4;
128 len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
129 break;
130 case 4:
131 offset += clip->x1 / 2;
132 len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
133 break;
134 default:
135 offset += clip->x1 * fb->format->cpp[0];
136 len *= fb->format->cpp[0];
137 break;
138 }
139
140 src = fb_helper->info->screen_buffer + offset;
141 iosys_map_incr(dst, offset); /* go to first pixel within clip rect */
142
143 for (y = clip->y1; y < clip->y2; y++) {
144 iosys_map_memcpy_to(dst, 0, src, len);
145 iosys_map_incr(dst, fb->pitches[0]);
146 src += fb->pitches[0];
147 }
148}
149
150static int drm_fbdev_dma_damage_blit(struct drm_fb_helper *fb_helper,
151 struct drm_clip_rect *clip)
152{
153 struct drm_client_buffer *buffer = fb_helper->buffer;
154 struct iosys_map dst;
155
156 /*
157 * For fbdev emulation, we only have to protect against fbdev modeset
158 * operations. Nothing else will involve the client buffer's BO. So it
159 * is sufficient to acquire struct drm_fb_helper.lock here.
160 */
161 mutex_lock(&fb_helper->lock);
162
163 dst = buffer->map;
164 drm_fbdev_dma_damage_blit_real(fb_helper, clip, &dst);
165
166 mutex_unlock(&fb_helper->lock);
167
168 return 0;
169}
170static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper,
171 struct drm_clip_rect *clip)
172{
173 struct drm_device *dev = helper->dev;
174 int ret;
175
176 /* Call damage handlers only if necessary */
177 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
178 return 0;
179
180 if (helper->fb->funcs->dirty) {
181 ret = drm_fbdev_dma_damage_blit(helper, clip);
182 if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
183 return ret;
184
185 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
186 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
187 return ret;
188 }
189
190 return 0;
191}
192
193static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {
194 .fb_dirty = drm_fbdev_dma_helper_fb_dirty,
195};
196
197/*
198 * struct drm_fb_helper
199 */
200
201static int drm_fbdev_dma_driver_fbdev_probe_tail(struct drm_fb_helper *fb_helper,
202 struct drm_fb_helper_surface_size *sizes)
203{
204 struct drm_device *dev = fb_helper->dev;
205 struct drm_client_buffer *buffer = fb_helper->buffer;
206 struct drm_gem_dma_object *dma_obj = to_drm_gem_dma_obj(buffer->gem);
207 struct drm_framebuffer *fb = fb_helper->fb;
208 struct fb_info *info = fb_helper->info;
209 struct iosys_map map = buffer->map;
210
211 info->fbops = &drm_fbdev_dma_fb_ops;
212
213 /* screen */
214 info->flags |= FBINFO_VIRTFB; /* system memory */
215 if (dma_obj->map_noncoherent)
216 info->flags |= FBINFO_READS_FAST; /* signal caching */
217 info->screen_size = sizes->surface_height * fb->pitches[0];
218 info->screen_buffer = map.vaddr;
219 if (!(info->flags & FBINFO_HIDE_SMEM_START)) {
220 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer)))
221 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
222 }
223 info->fix.smem_len = info->screen_size;
224
225 return 0;
226}
227
228static int drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(struct drm_fb_helper *fb_helper,
229 struct drm_fb_helper_surface_size *sizes)
230{
231 struct drm_client_buffer *buffer = fb_helper->buffer;
232 struct fb_info *info = fb_helper->info;
233 size_t screen_size = buffer->gem->size;
234 void *screen_buffer;
235 int ret;
236
237 /*
238 * Deferred I/O requires struct page for framebuffer memory,
239 * which is not guaranteed for all DMA ranges. We thus create
240 * a shadow buffer in system memory.
241 */
242 screen_buffer = vzalloc(screen_size);
243 if (!screen_buffer)
244 return -ENOMEM;
245
246 info->fbops = &drm_fbdev_dma_shadowed_fb_ops;
247
248 /* screen */
249 info->flags |= FBINFO_VIRTFB; /* system memory */
250 info->flags |= FBINFO_READS_FAST; /* signal caching */
251 info->screen_buffer = screen_buffer;
252 info->fix.smem_len = screen_size;
253
254 fb_helper->fbdefio.delay = HZ / 20;
255 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
256
257 info->fbdefio = &fb_helper->fbdefio;
258 ret = fb_deferred_io_init(info);
259 if (ret)
260 goto err_vfree;
261
262 return 0;
263
264err_vfree:
265 vfree(screen_buffer);
266 return ret;
267}
268
269int drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
270 struct drm_fb_helper_surface_size *sizes)
271{
272 struct drm_client_dev *client = &fb_helper->client;
273 struct drm_device *dev = fb_helper->dev;
274 struct drm_client_buffer *buffer;
275 struct drm_framebuffer *fb;
276 struct fb_info *info;
277 u32 format;
278 struct iosys_map map;
279 int ret;
280
281 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
282 sizes->surface_width, sizes->surface_height,
283 sizes->surface_bpp);
284
285 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp,
286 sizes->surface_depth);
287 buffer = drm_client_framebuffer_create(client, sizes->surface_width,
288 sizes->surface_height, format);
289 if (IS_ERR(buffer))
290 return PTR_ERR(buffer);
291
292 fb = buffer->fb;
293
294 ret = drm_client_buffer_vmap(buffer, &map);
295 if (ret) {
296 goto err_drm_client_buffer_delete;
297 } else if (drm_WARN_ON(dev, map.is_iomem)) {
298 ret = -ENODEV; /* I/O memory not supported; use generic emulation */
299 goto err_drm_client_buffer_delete;
300 }
301
302 fb_helper->funcs = &drm_fbdev_dma_helper_funcs;
303 fb_helper->buffer = buffer;
304 fb_helper->fb = fb;
305
306 info = drm_fb_helper_alloc_info(fb_helper);
307 if (IS_ERR(info)) {
308 ret = PTR_ERR(info);
309 goto err_drm_client_buffer_vunmap;
310 }
311
312 drm_fb_helper_fill_info(info, fb_helper, sizes);
313
314 if (fb->funcs->dirty)
315 ret = drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(fb_helper, sizes);
316 else
317 ret = drm_fbdev_dma_driver_fbdev_probe_tail(fb_helper, sizes);
318 if (ret)
319 goto err_drm_fb_helper_release_info;
320
321 return 0;
322
323err_drm_fb_helper_release_info:
324 drm_fb_helper_release_info(fb_helper);
325err_drm_client_buffer_vunmap:
326 fb_helper->fb = NULL;
327 fb_helper->buffer = NULL;
328 drm_client_buffer_vunmap(buffer);
329err_drm_client_buffer_delete:
330 drm_client_framebuffer_delete(buffer);
331 return ret;
332}
333EXPORT_SYMBOL(drm_fbdev_dma_driver_fbdev_probe);
1// SPDX-License-Identifier: MIT
2
3#include <linux/fb.h>
4
5#include <drm/drm_crtc_helper.h>
6#include <drm/drm_drv.h>
7#include <drm/drm_fb_helper.h>
8#include <drm/drm_framebuffer.h>
9#include <drm/drm_gem_dma_helper.h>
10
11#include <drm/drm_fbdev_dma.h>
12
13/*
14 * struct fb_ops
15 */
16
17static int drm_fbdev_dma_fb_open(struct fb_info *info, int user)
18{
19 struct drm_fb_helper *fb_helper = info->par;
20
21 /* No need to take a ref for fbcon because it unbinds on unregister */
22 if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
23 return -ENODEV;
24
25 return 0;
26}
27
28static int drm_fbdev_dma_fb_release(struct fb_info *info, int user)
29{
30 struct drm_fb_helper *fb_helper = info->par;
31
32 if (user)
33 module_put(fb_helper->dev->driver->fops->owner);
34
35 return 0;
36}
37
38static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
39{
40 struct drm_fb_helper *fb_helper = info->par;
41
42 if (!fb_helper->dev)
43 return;
44
45 drm_fb_helper_fini(fb_helper);
46
47 drm_client_buffer_vunmap(fb_helper->buffer);
48 drm_client_framebuffer_delete(fb_helper->buffer);
49 drm_client_release(&fb_helper->client);
50 drm_fb_helper_unprepare(fb_helper);
51 kfree(fb_helper);
52}
53
54static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
55{
56 struct drm_fb_helper *fb_helper = info->par;
57
58 return drm_gem_prime_mmap(fb_helper->buffer->gem, vma);
59}
60
61static const struct fb_ops drm_fbdev_dma_fb_ops = {
62 .owner = THIS_MODULE,
63 .fb_open = drm_fbdev_dma_fb_open,
64 .fb_release = drm_fbdev_dma_fb_release,
65 __FB_DEFAULT_DMAMEM_OPS_RDWR,
66 DRM_FB_HELPER_DEFAULT_OPS,
67 __FB_DEFAULT_DMAMEM_OPS_DRAW,
68 .fb_mmap = drm_fbdev_dma_fb_mmap,
69 .fb_destroy = drm_fbdev_dma_fb_destroy,
70};
71
72/*
73 * struct drm_fb_helper
74 */
75
76static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper,
77 struct drm_fb_helper_surface_size *sizes)
78{
79 struct drm_client_dev *client = &fb_helper->client;
80 struct drm_device *dev = fb_helper->dev;
81 struct drm_client_buffer *buffer;
82 struct drm_gem_dma_object *dma_obj;
83 struct drm_framebuffer *fb;
84 struct fb_info *info;
85 u32 format;
86 struct iosys_map map;
87 int ret;
88
89 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
90 sizes->surface_width, sizes->surface_height,
91 sizes->surface_bpp);
92
93 format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
94 buffer = drm_client_framebuffer_create(client, sizes->surface_width,
95 sizes->surface_height, format);
96 if (IS_ERR(buffer))
97 return PTR_ERR(buffer);
98 dma_obj = to_drm_gem_dma_obj(buffer->gem);
99
100 fb = buffer->fb;
101 if (drm_WARN_ON(dev, fb->funcs->dirty)) {
102 ret = -ENODEV; /* damage handling not supported; use generic emulation */
103 goto err_drm_client_buffer_delete;
104 }
105
106 ret = drm_client_buffer_vmap(buffer, &map);
107 if (ret) {
108 goto err_drm_client_buffer_delete;
109 } else if (drm_WARN_ON(dev, map.is_iomem)) {
110 ret = -ENODEV; /* I/O memory not supported; use generic emulation */
111 goto err_drm_client_buffer_delete;
112 }
113
114 fb_helper->buffer = buffer;
115 fb_helper->fb = buffer->fb;
116
117 info = drm_fb_helper_alloc_info(fb_helper);
118 if (IS_ERR(info)) {
119 ret = PTR_ERR(info);
120 goto err_drm_client_buffer_vunmap;
121 }
122
123 drm_fb_helper_fill_info(info, fb_helper, sizes);
124
125 info->fbops = &drm_fbdev_dma_fb_ops;
126
127 /* screen */
128 info->flags |= FBINFO_VIRTFB; /* system memory */
129 if (dma_obj->map_noncoherent)
130 info->flags |= FBINFO_READS_FAST; /* signal caching */
131 info->screen_size = sizes->surface_height * fb->pitches[0];
132 info->screen_buffer = map.vaddr;
133 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
134 info->fix.smem_len = info->screen_size;
135
136 return 0;
137
138err_drm_client_buffer_vunmap:
139 fb_helper->fb = NULL;
140 fb_helper->buffer = NULL;
141 drm_client_buffer_vunmap(buffer);
142err_drm_client_buffer_delete:
143 drm_client_framebuffer_delete(buffer);
144 return ret;
145}
146
147static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {
148 .fb_probe = drm_fbdev_dma_helper_fb_probe,
149};
150
151/*
152 * struct drm_client_funcs
153 */
154
155static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client)
156{
157 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
158
159 if (fb_helper->info) {
160 drm_fb_helper_unregister_info(fb_helper);
161 } else {
162 drm_client_release(&fb_helper->client);
163 drm_fb_helper_unprepare(fb_helper);
164 kfree(fb_helper);
165 }
166}
167
168static int drm_fbdev_dma_client_restore(struct drm_client_dev *client)
169{
170 drm_fb_helper_lastclose(client->dev);
171
172 return 0;
173}
174
175static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client)
176{
177 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
178 struct drm_device *dev = client->dev;
179 int ret;
180
181 if (dev->fb_helper)
182 return drm_fb_helper_hotplug_event(dev->fb_helper);
183
184 ret = drm_fb_helper_init(dev, fb_helper);
185 if (ret)
186 goto err_drm_err;
187
188 if (!drm_drv_uses_atomic_modeset(dev))
189 drm_helper_disable_unused_functions(dev);
190
191 ret = drm_fb_helper_initial_config(fb_helper);
192 if (ret)
193 goto err_drm_fb_helper_fini;
194
195 return 0;
196
197err_drm_fb_helper_fini:
198 drm_fb_helper_fini(fb_helper);
199err_drm_err:
200 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret);
201 return ret;
202}
203
204static const struct drm_client_funcs drm_fbdev_dma_client_funcs = {
205 .owner = THIS_MODULE,
206 .unregister = drm_fbdev_dma_client_unregister,
207 .restore = drm_fbdev_dma_client_restore,
208 .hotplug = drm_fbdev_dma_client_hotplug,
209};
210
211/**
212 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers
213 * @dev: DRM device
214 * @preferred_bpp: Preferred bits per pixel for the device.
215 * 32 is used if this is zero.
216 *
217 * This function sets up fbdev emulation for GEM DMA drivers that support
218 * dumb buffers with a virtual address and that can be mmap'ed.
219 * drm_fbdev_dma_setup() shall be called after the DRM driver registered
220 * the new DRM device with drm_dev_register().
221 *
222 * Restore, hotplug events and teardown are all taken care of. Drivers that do
223 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
224 * Simple drivers might use drm_mode_config_helper_suspend().
225 *
226 * This function is safe to call even when there are no connectors present.
227 * Setup will be retried on the next hotplug event.
228 *
229 * The fbdev is destroyed by drm_dev_unregister().
230 */
231void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp)
232{
233 struct drm_fb_helper *fb_helper;
234 int ret;
235
236 drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
237 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
238
239 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
240 if (!fb_helper)
241 return;
242 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs);
243
244 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs);
245 if (ret) {
246 drm_err(dev, "Failed to register client: %d\n", ret);
247 goto err_drm_client_init;
248 }
249
250 drm_client_register(&fb_helper->client);
251
252 return;
253
254err_drm_client_init:
255 drm_fb_helper_unprepare(fb_helper);
256 kfree(fb_helper);
257}
258EXPORT_SYMBOL(drm_fbdev_dma_setup);