1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | |
3 | #include <linux/iosys-map.h> |
4 | #include <linux/module.h> |
5 | |
6 | #include <drm/drm_debugfs.h> |
7 | #include <drm/drm_device.h> |
8 | #include <drm/drm_drv.h> |
9 | #include <drm/drm_file.h> |
10 | #include <drm/drm_framebuffer.h> |
11 | #include <drm/drm_gem_atomic_helper.h> |
12 | #include <drm/drm_gem_framebuffer_helper.h> |
13 | #include <drm/drm_gem_ttm_helper.h> |
14 | #include <drm/drm_gem_vram_helper.h> |
15 | #include <drm/drm_managed.h> |
16 | #include <drm/drm_mode.h> |
17 | #include <drm/drm_plane.h> |
18 | #include <drm/drm_prime.h> |
19 | #include <drm/drm_simple_kms_helper.h> |
20 | |
21 | #include <drm/ttm/ttm_range_manager.h> |
22 | #include <drm/ttm/ttm_tt.h> |
23 | |
24 | static const struct drm_gem_object_funcs drm_gem_vram_object_funcs; |
25 | |
26 | /** |
27 | * DOC: overview |
28 | * |
29 | * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM |
30 | * buffer object that is backed by video RAM (VRAM). It can be used for |
31 | * framebuffer devices with dedicated memory. |
32 | * |
33 | * The data structure &struct drm_vram_mm and its helpers implement a memory |
34 | * manager for simple framebuffer devices with dedicated video memory. GEM |
35 | * VRAM buffer objects are either placed in the video memory or remain evicted |
36 | * to system memory. |
37 | * |
38 | * With the GEM interface userspace applications create, manage and destroy |
39 | * graphics buffers, such as an on-screen framebuffer. GEM does not provide |
40 | * an implementation of these interfaces. It's up to the DRM driver to |
41 | * provide an implementation that suits the hardware. If the hardware device |
42 | * contains dedicated video memory, the DRM driver can use the VRAM helper |
43 | * library. Each active buffer object is stored in video RAM. Active |
44 | * buffer are used for drawing the current frame, typically something like |
45 | * the frame's scanout buffer or the cursor image. If there's no more space |
46 | * left in VRAM, inactive GEM objects can be moved to system memory. |
47 | * |
48 | * To initialize the VRAM helper library call drmm_vram_helper_init(). |
49 | * The function allocates and initializes an instance of &struct drm_vram_mm |
50 | * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize |
51 | * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize |
52 | * &struct file_operations; as illustrated below. |
53 | * |
54 | * .. code-block:: c |
55 | * |
56 | * struct file_operations fops ={ |
57 | * .owner = THIS_MODULE, |
58 | * DRM_VRAM_MM_FILE_OPERATION |
59 | * }; |
60 | * struct drm_driver drv = { |
61 | * .driver_feature = DRM_ ... , |
62 | * .fops = &fops, |
63 | * DRM_GEM_VRAM_DRIVER |
64 | * }; |
65 | * |
66 | * int init_drm_driver() |
67 | * { |
68 | * struct drm_device *dev; |
69 | * uint64_t vram_base; |
70 | * unsigned long vram_size; |
71 | * int ret; |
72 | * |
73 | * // setup device, vram base and size |
74 | * // ... |
75 | * |
76 | * ret = drmm_vram_helper_init(dev, vram_base, vram_size); |
77 | * if (ret) |
78 | * return ret; |
79 | * return 0; |
80 | * } |
81 | * |
82 | * This creates an instance of &struct drm_vram_mm, exports DRM userspace |
83 | * interfaces for GEM buffer management and initializes file operations to |
84 | * allow for accessing created GEM buffers. With this setup, the DRM driver |
85 | * manages an area of video RAM with VRAM MM and provides GEM VRAM objects |
86 | * to userspace. |
87 | * |
88 | * You don't have to clean up the instance of VRAM MM. |
89 | * drmm_vram_helper_init() is a managed interface that installs a |
90 | * clean-up handler to run during the DRM device's release. |
91 | * |
92 | * For drawing or scanout operations, rsp. buffer objects have to be pinned |
93 | * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or |
94 | * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system |
95 | * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards. |
96 | * |
97 | * A buffer object that is pinned in video RAM has a fixed address within that |
98 | * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically |
99 | * it's used to program the hardware's scanout engine for framebuffers, set |
100 | * the cursor overlay's image for a mouse cursor, or use it as input to the |
101 | * hardware's drawing engine. |
102 | * |
103 | * To access a buffer object's memory from the DRM driver, call |
104 | * drm_gem_vram_vmap(). It maps the buffer into kernel address |
105 | * space and returns the memory address. Use drm_gem_vram_vunmap() to |
106 | * release the mapping. |
107 | */ |
108 | |
109 | /* |
110 | * Buffer-objects helpers |
111 | */ |
112 | |
113 | static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo) |
114 | { |
115 | /* We got here via ttm_bo_put(), which means that the |
116 | * TTM buffer object in 'bo' has already been cleaned |
117 | * up; only release the GEM object. |
118 | */ |
119 | |
120 | WARN_ON(gbo->vmap_use_count); |
121 | WARN_ON(iosys_map_is_set(&gbo->map)); |
122 | |
123 | drm_gem_object_release(obj: &gbo->bo.base); |
124 | } |
125 | |
126 | static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo) |
127 | { |
128 | drm_gem_vram_cleanup(gbo); |
129 | kfree(objp: gbo); |
130 | } |
131 | |
132 | static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo) |
133 | { |
134 | struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo); |
135 | |
136 | drm_gem_vram_destroy(gbo); |
137 | } |
138 | |
139 | static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo, |
140 | unsigned long pl_flag) |
141 | { |
142 | u32 invariant_flags = 0; |
143 | unsigned int i; |
144 | unsigned int c = 0; |
145 | |
146 | if (pl_flag & DRM_GEM_VRAM_PL_FLAG_TOPDOWN) |
147 | invariant_flags = TTM_PL_FLAG_TOPDOWN; |
148 | |
149 | gbo->placement.placement = gbo->placements; |
150 | |
151 | if (pl_flag & DRM_GEM_VRAM_PL_FLAG_VRAM) { |
152 | gbo->placements[c].mem_type = TTM_PL_VRAM; |
153 | gbo->placements[c++].flags = invariant_flags; |
154 | } |
155 | |
156 | if (pl_flag & DRM_GEM_VRAM_PL_FLAG_SYSTEM || !c) { |
157 | gbo->placements[c].mem_type = TTM_PL_SYSTEM; |
158 | gbo->placements[c++].flags = invariant_flags; |
159 | } |
160 | |
161 | gbo->placement.num_placement = c; |
162 | |
163 | for (i = 0; i < c; ++i) { |
164 | gbo->placements[i].fpfn = 0; |
165 | gbo->placements[i].lpfn = 0; |
166 | } |
167 | } |
168 | |
169 | /** |
170 | * drm_gem_vram_create() - Creates a VRAM-backed GEM object |
171 | * @dev: the DRM device |
172 | * @size: the buffer size in bytes |
173 | * @pg_align: the buffer's alignment in multiples of the page size |
174 | * |
175 | * GEM objects are allocated by calling struct drm_driver.gem_create_object, |
176 | * if set. Otherwise kzalloc() will be used. Drivers can set their own GEM |
177 | * object functions in struct drm_driver.gem_create_object. If no functions |
178 | * are set, the new GEM object will use the default functions from GEM VRAM |
179 | * helpers. |
180 | * |
181 | * Returns: |
182 | * A new instance of &struct drm_gem_vram_object on success, or |
183 | * an ERR_PTR()-encoded error code otherwise. |
184 | */ |
185 | struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev, |
186 | size_t size, |
187 | unsigned long pg_align) |
188 | { |
189 | struct drm_gem_vram_object *gbo; |
190 | struct drm_gem_object *gem; |
191 | struct drm_vram_mm *vmm = dev->vram_mm; |
192 | struct ttm_device *bdev; |
193 | int ret; |
194 | |
195 | if (WARN_ONCE(!vmm, "VRAM MM not initialized" )) |
196 | return ERR_PTR(error: -EINVAL); |
197 | |
198 | if (dev->driver->gem_create_object) { |
199 | gem = dev->driver->gem_create_object(dev, size); |
200 | if (IS_ERR(ptr: gem)) |
201 | return ERR_CAST(ptr: gem); |
202 | gbo = drm_gem_vram_of_gem(gem); |
203 | } else { |
204 | gbo = kzalloc(size: sizeof(*gbo), GFP_KERNEL); |
205 | if (!gbo) |
206 | return ERR_PTR(error: -ENOMEM); |
207 | gem = &gbo->bo.base; |
208 | } |
209 | |
210 | if (!gem->funcs) |
211 | gem->funcs = &drm_gem_vram_object_funcs; |
212 | |
213 | ret = drm_gem_object_init(dev, obj: gem, size); |
214 | if (ret) { |
215 | kfree(objp: gbo); |
216 | return ERR_PTR(error: ret); |
217 | } |
218 | |
219 | bdev = &vmm->bdev; |
220 | |
221 | gbo->bo.bdev = bdev; |
222 | drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM); |
223 | |
224 | /* |
225 | * A failing ttm_bo_init will call ttm_buffer_object_destroy |
226 | * to release gbo->bo.base and kfree gbo. |
227 | */ |
228 | ret = ttm_bo_init_validate(bdev, bo: &gbo->bo, type: ttm_bo_type_device, |
229 | placement: &gbo->placement, alignment: pg_align, interruptible: false, NULL, NULL, |
230 | destroy: ttm_buffer_object_destroy); |
231 | if (ret) |
232 | return ERR_PTR(error: ret); |
233 | |
234 | return gbo; |
235 | } |
236 | EXPORT_SYMBOL(drm_gem_vram_create); |
237 | |
238 | /** |
239 | * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object |
240 | * @gbo: the GEM VRAM object |
241 | * |
242 | * See ttm_bo_put() for more information. |
243 | */ |
244 | void drm_gem_vram_put(struct drm_gem_vram_object *gbo) |
245 | { |
246 | ttm_bo_put(bo: &gbo->bo); |
247 | } |
248 | EXPORT_SYMBOL(drm_gem_vram_put); |
249 | |
250 | static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo) |
251 | { |
252 | /* Keep TTM behavior for now, remove when drivers are audited */ |
253 | if (WARN_ON_ONCE(!gbo->bo.resource || |
254 | gbo->bo.resource->mem_type == TTM_PL_SYSTEM)) |
255 | return 0; |
256 | |
257 | return gbo->bo.resource->start; |
258 | } |
259 | |
260 | /** |
261 | * drm_gem_vram_offset() - Returns a GEM VRAM object's offset in video memory |
262 | * @gbo: the GEM VRAM object |
263 | * |
264 | * This function returns the buffer object's offset in the device's video |
265 | * memory. The buffer object has to be pinned to %TTM_PL_VRAM. |
266 | * |
267 | * Returns: |
268 | * The buffer object's offset in video memory on success, or |
269 | * a negative errno code otherwise. |
270 | */ |
271 | s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo) |
272 | { |
273 | if (WARN_ON_ONCE(!gbo->bo.pin_count)) |
274 | return (s64)-ENODEV; |
275 | return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT; |
276 | } |
277 | EXPORT_SYMBOL(drm_gem_vram_offset); |
278 | |
279 | static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo, |
280 | unsigned long pl_flag) |
281 | { |
282 | struct ttm_operation_ctx ctx = { false, false }; |
283 | int ret; |
284 | |
285 | if (gbo->bo.pin_count) |
286 | goto out; |
287 | |
288 | if (pl_flag) |
289 | drm_gem_vram_placement(gbo, pl_flag); |
290 | |
291 | ret = ttm_bo_validate(bo: &gbo->bo, placement: &gbo->placement, ctx: &ctx); |
292 | if (ret < 0) |
293 | return ret; |
294 | |
295 | out: |
296 | ttm_bo_pin(bo: &gbo->bo); |
297 | |
298 | return 0; |
299 | } |
300 | |
301 | /** |
302 | * drm_gem_vram_pin() - Pins a GEM VRAM object in a region. |
303 | * @gbo: the GEM VRAM object |
304 | * @pl_flag: a bitmask of possible memory regions |
305 | * |
306 | * Pinning a buffer object ensures that it is not evicted from |
307 | * a memory region. A pinned buffer object has to be unpinned before |
308 | * it can be pinned to another region. If the pl_flag argument is 0, |
309 | * the buffer is pinned at its current location (video RAM or system |
310 | * memory). |
311 | * |
312 | * Small buffer objects, such as cursor images, can lead to memory |
313 | * fragmentation if they are pinned in the middle of video RAM. This |
314 | * is especially a problem on devices with only a small amount of |
315 | * video RAM. Fragmentation can prevent the primary framebuffer from |
316 | * fitting in, even though there's enough memory overall. The modifier |
317 | * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned |
318 | * at the high end of the memory region to avoid fragmentation. |
319 | * |
320 | * Returns: |
321 | * 0 on success, or |
322 | * a negative error code otherwise. |
323 | */ |
324 | int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag) |
325 | { |
326 | int ret; |
327 | |
328 | ret = ttm_bo_reserve(bo: &gbo->bo, interruptible: true, no_wait: false, NULL); |
329 | if (ret) |
330 | return ret; |
331 | ret = drm_gem_vram_pin_locked(gbo, pl_flag); |
332 | ttm_bo_unreserve(bo: &gbo->bo); |
333 | |
334 | return ret; |
335 | } |
336 | EXPORT_SYMBOL(drm_gem_vram_pin); |
337 | |
338 | static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo) |
339 | { |
340 | ttm_bo_unpin(bo: &gbo->bo); |
341 | } |
342 | |
343 | /** |
344 | * drm_gem_vram_unpin() - Unpins a GEM VRAM object |
345 | * @gbo: the GEM VRAM object |
346 | * |
347 | * Returns: |
348 | * 0 on success, or |
349 | * a negative error code otherwise. |
350 | */ |
351 | int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo) |
352 | { |
353 | int ret; |
354 | |
355 | ret = ttm_bo_reserve(bo: &gbo->bo, interruptible: true, no_wait: false, NULL); |
356 | if (ret) |
357 | return ret; |
358 | |
359 | drm_gem_vram_unpin_locked(gbo); |
360 | ttm_bo_unreserve(bo: &gbo->bo); |
361 | |
362 | return 0; |
363 | } |
364 | EXPORT_SYMBOL(drm_gem_vram_unpin); |
365 | |
366 | static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo, |
367 | struct iosys_map *map) |
368 | { |
369 | int ret; |
370 | |
371 | if (gbo->vmap_use_count > 0) |
372 | goto out; |
373 | |
374 | /* |
375 | * VRAM helpers unmap the BO only on demand. So the previous |
376 | * page mapping might still be around. Only vmap if the there's |
377 | * no mapping present. |
378 | */ |
379 | if (iosys_map_is_null(map: &gbo->map)) { |
380 | ret = ttm_bo_vmap(bo: &gbo->bo, map: &gbo->map); |
381 | if (ret) |
382 | return ret; |
383 | } |
384 | |
385 | out: |
386 | ++gbo->vmap_use_count; |
387 | *map = gbo->map; |
388 | |
389 | return 0; |
390 | } |
391 | |
392 | static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo, |
393 | struct iosys_map *map) |
394 | { |
395 | struct drm_device *dev = gbo->bo.base.dev; |
396 | |
397 | if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count)) |
398 | return; |
399 | |
400 | if (drm_WARN_ON_ONCE(dev, !iosys_map_is_equal(&gbo->map, map))) |
401 | return; /* BUG: map not mapped from this BO */ |
402 | |
403 | if (--gbo->vmap_use_count > 0) |
404 | return; |
405 | |
406 | /* |
407 | * Permanently mapping and unmapping buffers adds overhead from |
408 | * updating the page tables and creates debugging output. Therefore, |
409 | * we delay the actual unmap operation until the BO gets evicted |
410 | * from memory. See drm_gem_vram_bo_driver_move_notify(). |
411 | */ |
412 | } |
413 | |
414 | /** |
415 | * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address |
416 | * space |
417 | * @gbo: The GEM VRAM object to map |
418 | * @map: Returns the kernel virtual address of the VRAM GEM object's backing |
419 | * store. |
420 | * |
421 | * The vmap function pins a GEM VRAM object to its current location, either |
422 | * system or video memory, and maps its buffer into kernel address space. |
423 | * As pinned object cannot be relocated, you should avoid pinning objects |
424 | * permanently. Call drm_gem_vram_vunmap() with the returned address to |
425 | * unmap and unpin the GEM VRAM object. |
426 | * |
427 | * Returns: |
428 | * 0 on success, or a negative error code otherwise. |
429 | */ |
430 | int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct iosys_map *map) |
431 | { |
432 | int ret; |
433 | |
434 | dma_resv_assert_held(gbo->bo.base.resv); |
435 | |
436 | ret = drm_gem_vram_pin_locked(gbo, pl_flag: 0); |
437 | if (ret) |
438 | return ret; |
439 | ret = drm_gem_vram_kmap_locked(gbo, map); |
440 | if (ret) |
441 | goto err_drm_gem_vram_unpin_locked; |
442 | |
443 | return 0; |
444 | |
445 | err_drm_gem_vram_unpin_locked: |
446 | drm_gem_vram_unpin_locked(gbo); |
447 | return ret; |
448 | } |
449 | EXPORT_SYMBOL(drm_gem_vram_vmap); |
450 | |
451 | /** |
452 | * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object |
453 | * @gbo: The GEM VRAM object to unmap |
454 | * @map: Kernel virtual address where the VRAM GEM object was mapped |
455 | * |
456 | * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See |
457 | * the documentation for drm_gem_vram_vmap() for more information. |
458 | */ |
459 | void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, |
460 | struct iosys_map *map) |
461 | { |
462 | dma_resv_assert_held(gbo->bo.base.resv); |
463 | |
464 | drm_gem_vram_kunmap_locked(gbo, map); |
465 | drm_gem_vram_unpin_locked(gbo); |
466 | } |
467 | EXPORT_SYMBOL(drm_gem_vram_vunmap); |
468 | |
469 | /** |
470 | * drm_gem_vram_fill_create_dumb() - Helper for implementing |
471 | * &struct drm_driver.dumb_create |
472 | * |
473 | * @file: the DRM file |
474 | * @dev: the DRM device |
475 | * @pg_align: the buffer's alignment in multiples of the page size |
476 | * @pitch_align: the scanline's alignment in powers of 2 |
477 | * @args: the arguments as provided to |
478 | * &struct drm_driver.dumb_create |
479 | * |
480 | * This helper function fills &struct drm_mode_create_dumb, which is used |
481 | * by &struct drm_driver.dumb_create. Implementations of this interface |
482 | * should forwards their arguments to this helper, plus the driver-specific |
483 | * parameters. |
484 | * |
485 | * Returns: |
486 | * 0 on success, or |
487 | * a negative error code otherwise. |
488 | */ |
489 | int drm_gem_vram_fill_create_dumb(struct drm_file *file, |
490 | struct drm_device *dev, |
491 | unsigned long pg_align, |
492 | unsigned long pitch_align, |
493 | struct drm_mode_create_dumb *args) |
494 | { |
495 | size_t pitch, size; |
496 | struct drm_gem_vram_object *gbo; |
497 | int ret; |
498 | u32 handle; |
499 | |
500 | pitch = args->width * DIV_ROUND_UP(args->bpp, 8); |
501 | if (pitch_align) { |
502 | if (WARN_ON_ONCE(!is_power_of_2(pitch_align))) |
503 | return -EINVAL; |
504 | pitch = ALIGN(pitch, pitch_align); |
505 | } |
506 | size = pitch * args->height; |
507 | |
508 | size = roundup(size, PAGE_SIZE); |
509 | if (!size) |
510 | return -EINVAL; |
511 | |
512 | gbo = drm_gem_vram_create(dev, size, pg_align); |
513 | if (IS_ERR(ptr: gbo)) |
514 | return PTR_ERR(ptr: gbo); |
515 | |
516 | ret = drm_gem_handle_create(file_priv: file, obj: &gbo->bo.base, handlep: &handle); |
517 | if (ret) |
518 | goto err_drm_gem_object_put; |
519 | |
520 | drm_gem_object_put(obj: &gbo->bo.base); |
521 | |
522 | args->pitch = pitch; |
523 | args->size = size; |
524 | args->handle = handle; |
525 | |
526 | return 0; |
527 | |
528 | err_drm_gem_object_put: |
529 | drm_gem_object_put(obj: &gbo->bo.base); |
530 | return ret; |
531 | } |
532 | EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb); |
533 | |
534 | /* |
535 | * Helpers for struct ttm_device_funcs |
536 | */ |
537 | |
538 | static bool drm_is_gem_vram(struct ttm_buffer_object *bo) |
539 | { |
540 | return (bo->destroy == ttm_buffer_object_destroy); |
541 | } |
542 | |
543 | static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo, |
544 | struct ttm_placement *pl) |
545 | { |
546 | drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM); |
547 | *pl = gbo->placement; |
548 | } |
549 | |
550 | static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo) |
551 | { |
552 | struct ttm_buffer_object *bo = &gbo->bo; |
553 | struct drm_device *dev = bo->base.dev; |
554 | |
555 | if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count)) |
556 | return; |
557 | |
558 | ttm_bo_vunmap(bo, map: &gbo->map); |
559 | iosys_map_clear(map: &gbo->map); /* explicitly clear mapping for next vmap call */ |
560 | } |
561 | |
562 | static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo, |
563 | bool evict, |
564 | struct ttm_operation_ctx *ctx, |
565 | struct ttm_resource *new_mem) |
566 | { |
567 | drm_gem_vram_bo_driver_move_notify(gbo); |
568 | return ttm_bo_move_memcpy(bo: &gbo->bo, ctx, new_mem); |
569 | } |
570 | |
571 | /* |
572 | * Helpers for struct drm_gem_object_funcs |
573 | */ |
574 | |
575 | /** |
576 | * drm_gem_vram_object_free() - Implements &struct drm_gem_object_funcs.free |
577 | * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem |
578 | */ |
579 | static void drm_gem_vram_object_free(struct drm_gem_object *gem) |
580 | { |
581 | struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); |
582 | |
583 | drm_gem_vram_put(gbo); |
584 | } |
585 | |
586 | /* |
587 | * Helpers for dump buffers |
588 | */ |
589 | |
590 | /** |
591 | * drm_gem_vram_driver_dumb_create() - Implements &struct drm_driver.dumb_create |
592 | * @file: the DRM file |
593 | * @dev: the DRM device |
594 | * @args: the arguments as provided to |
595 | * &struct drm_driver.dumb_create |
596 | * |
597 | * This function requires the driver to use @drm_device.vram_mm for its |
598 | * instance of VRAM MM. |
599 | * |
600 | * Returns: |
601 | * 0 on success, or |
602 | * a negative error code otherwise. |
603 | */ |
604 | int drm_gem_vram_driver_dumb_create(struct drm_file *file, |
605 | struct drm_device *dev, |
606 | struct drm_mode_create_dumb *args) |
607 | { |
608 | if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized" )) |
609 | return -EINVAL; |
610 | |
611 | return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args); |
612 | } |
613 | EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create); |
614 | |
615 | /* |
616 | * Helpers for struct drm_plane_helper_funcs |
617 | */ |
618 | |
619 | static void __drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane, |
620 | struct drm_plane_state *state, |
621 | unsigned int num_planes) |
622 | { |
623 | struct drm_gem_object *obj; |
624 | struct drm_gem_vram_object *gbo; |
625 | struct drm_framebuffer *fb = state->fb; |
626 | |
627 | while (num_planes) { |
628 | --num_planes; |
629 | obj = drm_gem_fb_get_obj(fb, plane: num_planes); |
630 | if (!obj) |
631 | continue; |
632 | gbo = drm_gem_vram_of_gem(gem: obj); |
633 | drm_gem_vram_unpin(gbo); |
634 | } |
635 | } |
636 | |
637 | /** |
638 | * drm_gem_vram_plane_helper_prepare_fb() - Implements &struct |
639 | * drm_plane_helper_funcs.prepare_fb |
640 | * @plane: a DRM plane |
641 | * @new_state: the plane's new state |
642 | * |
643 | * During plane updates, this function sets the plane's fence and |
644 | * pins the GEM VRAM objects of the plane's new framebuffer to VRAM. |
645 | * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them. |
646 | * |
647 | * Returns: |
648 | * 0 on success, or |
649 | * a negative errno code otherwise. |
650 | */ |
651 | int |
652 | drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane, |
653 | struct drm_plane_state *new_state) |
654 | { |
655 | struct drm_framebuffer *fb = new_state->fb; |
656 | struct drm_gem_vram_object *gbo; |
657 | struct drm_gem_object *obj; |
658 | unsigned int i; |
659 | int ret; |
660 | |
661 | if (!fb) |
662 | return 0; |
663 | |
664 | for (i = 0; i < fb->format->num_planes; ++i) { |
665 | obj = drm_gem_fb_get_obj(fb, plane: i); |
666 | if (!obj) { |
667 | ret = -EINVAL; |
668 | goto err_drm_gem_vram_unpin; |
669 | } |
670 | gbo = drm_gem_vram_of_gem(gem: obj); |
671 | ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM); |
672 | if (ret) |
673 | goto err_drm_gem_vram_unpin; |
674 | } |
675 | |
676 | ret = drm_gem_plane_helper_prepare_fb(plane, state: new_state); |
677 | if (ret) |
678 | goto err_drm_gem_vram_unpin; |
679 | |
680 | return 0; |
681 | |
682 | err_drm_gem_vram_unpin: |
683 | __drm_gem_vram_plane_helper_cleanup_fb(plane, state: new_state, num_planes: i); |
684 | return ret; |
685 | } |
686 | EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb); |
687 | |
688 | /** |
689 | * drm_gem_vram_plane_helper_cleanup_fb() - Implements &struct |
690 | * drm_plane_helper_funcs.cleanup_fb |
691 | * @plane: a DRM plane |
692 | * @old_state: the plane's old state |
693 | * |
694 | * During plane updates, this function unpins the GEM VRAM |
695 | * objects of the plane's old framebuffer from VRAM. Complements |
696 | * drm_gem_vram_plane_helper_prepare_fb(). |
697 | */ |
698 | void |
699 | drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane, |
700 | struct drm_plane_state *old_state) |
701 | { |
702 | struct drm_framebuffer *fb = old_state->fb; |
703 | |
704 | if (!fb) |
705 | return; |
706 | |
707 | __drm_gem_vram_plane_helper_cleanup_fb(plane, state: old_state, num_planes: fb->format->num_planes); |
708 | } |
709 | EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb); |
710 | |
711 | /* |
712 | * Helpers for struct drm_simple_display_pipe_funcs |
713 | */ |
714 | |
715 | /** |
716 | * drm_gem_vram_simple_display_pipe_prepare_fb() - Implements &struct |
717 | * drm_simple_display_pipe_funcs.prepare_fb |
718 | * @pipe: a simple display pipe |
719 | * @new_state: the plane's new state |
720 | * |
721 | * During plane updates, this function pins the GEM VRAM |
722 | * objects of the plane's new framebuffer to VRAM. Call |
723 | * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them. |
724 | * |
725 | * Returns: |
726 | * 0 on success, or |
727 | * a negative errno code otherwise. |
728 | */ |
729 | int drm_gem_vram_simple_display_pipe_prepare_fb( |
730 | struct drm_simple_display_pipe *pipe, |
731 | struct drm_plane_state *new_state) |
732 | { |
733 | return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state); |
734 | } |
735 | EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb); |
736 | |
737 | /** |
738 | * drm_gem_vram_simple_display_pipe_cleanup_fb() - Implements &struct |
739 | * drm_simple_display_pipe_funcs.cleanup_fb |
740 | * @pipe: a simple display pipe |
741 | * @old_state: the plane's old state |
742 | * |
743 | * During plane updates, this function unpins the GEM VRAM |
744 | * objects of the plane's old framebuffer from VRAM. Complements |
745 | * drm_gem_vram_simple_display_pipe_prepare_fb(). |
746 | */ |
747 | void drm_gem_vram_simple_display_pipe_cleanup_fb( |
748 | struct drm_simple_display_pipe *pipe, |
749 | struct drm_plane_state *old_state) |
750 | { |
751 | drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state); |
752 | } |
753 | EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb); |
754 | |
755 | /* |
756 | * PRIME helpers |
757 | */ |
758 | |
759 | /** |
760 | * drm_gem_vram_object_pin() - Implements &struct drm_gem_object_funcs.pin |
761 | * @gem: The GEM object to pin |
762 | * |
763 | * Returns: |
764 | * 0 on success, or |
765 | * a negative errno code otherwise. |
766 | */ |
767 | static int drm_gem_vram_object_pin(struct drm_gem_object *gem) |
768 | { |
769 | struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); |
770 | |
771 | /* Fbdev console emulation is the use case of these PRIME |
772 | * helpers. This may involve updating a hardware buffer from |
773 | * a shadow FB. We pin the buffer to it's current location |
774 | * (either video RAM or system memory) to prevent it from |
775 | * being relocated during the update operation. If you require |
776 | * the buffer to be pinned to VRAM, implement a callback that |
777 | * sets the flags accordingly. |
778 | */ |
779 | return drm_gem_vram_pin(gbo, 0); |
780 | } |
781 | |
782 | /** |
783 | * drm_gem_vram_object_unpin() - Implements &struct drm_gem_object_funcs.unpin |
784 | * @gem: The GEM object to unpin |
785 | */ |
786 | static void drm_gem_vram_object_unpin(struct drm_gem_object *gem) |
787 | { |
788 | struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); |
789 | |
790 | drm_gem_vram_unpin(gbo); |
791 | } |
792 | |
793 | /** |
794 | * drm_gem_vram_object_vmap() - |
795 | * Implements &struct drm_gem_object_funcs.vmap |
796 | * @gem: The GEM object to map |
797 | * @map: Returns the kernel virtual address of the VRAM GEM object's backing |
798 | * store. |
799 | * |
800 | * Returns: |
801 | * 0 on success, or a negative error code otherwise. |
802 | */ |
803 | static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, |
804 | struct iosys_map *map) |
805 | { |
806 | struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); |
807 | |
808 | return drm_gem_vram_vmap(gbo, map); |
809 | } |
810 | |
811 | /** |
812 | * drm_gem_vram_object_vunmap() - |
813 | * Implements &struct drm_gem_object_funcs.vunmap |
814 | * @gem: The GEM object to unmap |
815 | * @map: Kernel virtual address where the VRAM GEM object was mapped |
816 | */ |
817 | static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, |
818 | struct iosys_map *map) |
819 | { |
820 | struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); |
821 | |
822 | drm_gem_vram_vunmap(gbo, map); |
823 | } |
824 | |
825 | /* |
826 | * GEM object funcs |
827 | */ |
828 | |
829 | static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = { |
830 | .free = drm_gem_vram_object_free, |
831 | .pin = drm_gem_vram_object_pin, |
832 | .unpin = drm_gem_vram_object_unpin, |
833 | .vmap = drm_gem_vram_object_vmap, |
834 | .vunmap = drm_gem_vram_object_vunmap, |
835 | .mmap = drm_gem_ttm_mmap, |
836 | .print_info = drm_gem_ttm_print_info, |
837 | }; |
838 | |
839 | /* |
840 | * VRAM memory manager |
841 | */ |
842 | |
843 | /* |
844 | * TTM TT |
845 | */ |
846 | |
847 | static void bo_driver_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt) |
848 | { |
849 | ttm_tt_fini(ttm: tt); |
850 | kfree(objp: tt); |
851 | } |
852 | |
853 | /* |
854 | * TTM BO device |
855 | */ |
856 | |
857 | static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo, |
858 | uint32_t page_flags) |
859 | { |
860 | struct ttm_tt *tt; |
861 | int ret; |
862 | |
863 | tt = kzalloc(size: sizeof(*tt), GFP_KERNEL); |
864 | if (!tt) |
865 | return NULL; |
866 | |
867 | ret = ttm_tt_init(ttm: tt, bo, page_flags, caching: ttm_cached, extra_pages: 0); |
868 | if (ret < 0) |
869 | goto err_ttm_tt_init; |
870 | |
871 | return tt; |
872 | |
873 | err_ttm_tt_init: |
874 | kfree(objp: tt); |
875 | return NULL; |
876 | } |
877 | |
878 | static void bo_driver_evict_flags(struct ttm_buffer_object *bo, |
879 | struct ttm_placement *placement) |
880 | { |
881 | struct drm_gem_vram_object *gbo; |
882 | |
883 | /* TTM may pass BOs that are not GEM VRAM BOs. */ |
884 | if (!drm_is_gem_vram(bo)) |
885 | return; |
886 | |
887 | gbo = drm_gem_vram_of_bo(bo); |
888 | |
889 | drm_gem_vram_bo_driver_evict_flags(gbo, pl: placement); |
890 | } |
891 | |
892 | static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo) |
893 | { |
894 | struct drm_gem_vram_object *gbo; |
895 | |
896 | /* TTM may pass BOs that are not GEM VRAM BOs. */ |
897 | if (!drm_is_gem_vram(bo)) |
898 | return; |
899 | |
900 | gbo = drm_gem_vram_of_bo(bo); |
901 | |
902 | drm_gem_vram_bo_driver_move_notify(gbo); |
903 | } |
904 | |
905 | static int bo_driver_move(struct ttm_buffer_object *bo, |
906 | bool evict, |
907 | struct ttm_operation_ctx *ctx, |
908 | struct ttm_resource *new_mem, |
909 | struct ttm_place *hop) |
910 | { |
911 | struct drm_gem_vram_object *gbo; |
912 | |
913 | if (!bo->resource) { |
914 | if (new_mem->mem_type != TTM_PL_SYSTEM) { |
915 | hop->mem_type = TTM_PL_SYSTEM; |
916 | hop->flags = TTM_PL_FLAG_TEMPORARY; |
917 | return -EMULTIHOP; |
918 | } |
919 | |
920 | ttm_bo_move_null(bo, new_mem); |
921 | return 0; |
922 | } |
923 | |
924 | gbo = drm_gem_vram_of_bo(bo); |
925 | |
926 | return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem); |
927 | } |
928 | |
929 | static int bo_driver_io_mem_reserve(struct ttm_device *bdev, |
930 | struct ttm_resource *mem) |
931 | { |
932 | struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev); |
933 | |
934 | switch (mem->mem_type) { |
935 | case TTM_PL_SYSTEM: /* nothing to do */ |
936 | break; |
937 | case TTM_PL_VRAM: |
938 | mem->bus.offset = (mem->start << PAGE_SHIFT) + vmm->vram_base; |
939 | mem->bus.is_iomem = true; |
940 | mem->bus.caching = ttm_write_combined; |
941 | break; |
942 | default: |
943 | return -EINVAL; |
944 | } |
945 | |
946 | return 0; |
947 | } |
948 | |
949 | static struct ttm_device_funcs bo_driver = { |
950 | .ttm_tt_create = bo_driver_ttm_tt_create, |
951 | .ttm_tt_destroy = bo_driver_ttm_tt_destroy, |
952 | .eviction_valuable = ttm_bo_eviction_valuable, |
953 | .evict_flags = bo_driver_evict_flags, |
954 | .move = bo_driver_move, |
955 | .delete_mem_notify = bo_driver_delete_mem_notify, |
956 | .io_mem_reserve = bo_driver_io_mem_reserve, |
957 | }; |
958 | |
959 | /* |
960 | * struct drm_vram_mm |
961 | */ |
962 | |
963 | static int drm_vram_mm_debugfs(struct seq_file *m, void *data) |
964 | { |
965 | struct drm_debugfs_entry *entry = m->private; |
966 | struct drm_vram_mm *vmm = entry->dev->vram_mm; |
967 | struct ttm_resource_manager *man = ttm_manager_type(bdev: &vmm->bdev, TTM_PL_VRAM); |
968 | struct drm_printer p = drm_seq_file_printer(f: m); |
969 | |
970 | ttm_resource_manager_debug(man, p: &p); |
971 | return 0; |
972 | } |
973 | |
974 | static const struct drm_debugfs_info drm_vram_mm_debugfs_list[] = { |
975 | { "vram-mm" , drm_vram_mm_debugfs, 0, NULL }, |
976 | }; |
977 | |
978 | /** |
979 | * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file. |
980 | * |
981 | * @minor: drm minor device. |
982 | * |
983 | */ |
984 | void drm_vram_mm_debugfs_init(struct drm_minor *minor) |
985 | { |
986 | drm_debugfs_add_files(dev: minor->dev, files: drm_vram_mm_debugfs_list, |
987 | ARRAY_SIZE(drm_vram_mm_debugfs_list)); |
988 | } |
989 | EXPORT_SYMBOL(drm_vram_mm_debugfs_init); |
990 | |
991 | static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev, |
992 | uint64_t vram_base, size_t vram_size) |
993 | { |
994 | int ret; |
995 | |
996 | vmm->vram_base = vram_base; |
997 | vmm->vram_size = vram_size; |
998 | |
999 | ret = ttm_device_init(bdev: &vmm->bdev, funcs: &bo_driver, dev: dev->dev, |
1000 | mapping: dev->anon_inode->i_mapping, |
1001 | vma_manager: dev->vma_offset_manager, |
1002 | use_dma_alloc: false, use_dma32: true); |
1003 | if (ret) |
1004 | return ret; |
1005 | |
1006 | ret = ttm_range_man_init(bdev: &vmm->bdev, TTM_PL_VRAM, |
1007 | use_tt: false, p_size: vram_size >> PAGE_SHIFT); |
1008 | if (ret) |
1009 | return ret; |
1010 | |
1011 | return 0; |
1012 | } |
1013 | |
1014 | static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm) |
1015 | { |
1016 | ttm_range_man_fini(bdev: &vmm->bdev, TTM_PL_VRAM); |
1017 | ttm_device_fini(bdev: &vmm->bdev); |
1018 | } |
1019 | |
1020 | /* |
1021 | * Helpers for integration with struct drm_device |
1022 | */ |
1023 | |
1024 | static struct drm_vram_mm *drm_vram_helper_alloc_mm(struct drm_device *dev, uint64_t vram_base, |
1025 | size_t vram_size) |
1026 | { |
1027 | int ret; |
1028 | |
1029 | if (WARN_ON(dev->vram_mm)) |
1030 | return dev->vram_mm; |
1031 | |
1032 | dev->vram_mm = kzalloc(size: sizeof(*dev->vram_mm), GFP_KERNEL); |
1033 | if (!dev->vram_mm) |
1034 | return ERR_PTR(error: -ENOMEM); |
1035 | |
1036 | ret = drm_vram_mm_init(vmm: dev->vram_mm, dev, vram_base, vram_size); |
1037 | if (ret) |
1038 | goto err_kfree; |
1039 | |
1040 | return dev->vram_mm; |
1041 | |
1042 | err_kfree: |
1043 | kfree(objp: dev->vram_mm); |
1044 | dev->vram_mm = NULL; |
1045 | return ERR_PTR(error: ret); |
1046 | } |
1047 | |
1048 | static void drm_vram_helper_release_mm(struct drm_device *dev) |
1049 | { |
1050 | if (!dev->vram_mm) |
1051 | return; |
1052 | |
1053 | drm_vram_mm_cleanup(vmm: dev->vram_mm); |
1054 | kfree(objp: dev->vram_mm); |
1055 | dev->vram_mm = NULL; |
1056 | } |
1057 | |
1058 | static void drm_vram_mm_release(struct drm_device *dev, void *ptr) |
1059 | { |
1060 | drm_vram_helper_release_mm(dev); |
1061 | } |
1062 | |
1063 | /** |
1064 | * drmm_vram_helper_init - Initializes a device's instance of |
1065 | * &struct drm_vram_mm |
1066 | * @dev: the DRM device |
1067 | * @vram_base: the base address of the video memory |
1068 | * @vram_size: the size of the video memory in bytes |
1069 | * |
1070 | * Creates a new instance of &struct drm_vram_mm and stores it in |
1071 | * struct &drm_device.vram_mm. The instance is auto-managed and cleaned |
1072 | * up as part of device cleanup. Calling this function multiple times |
1073 | * will generate an error message. |
1074 | * |
1075 | * Returns: |
1076 | * 0 on success, or a negative errno code otherwise. |
1077 | */ |
1078 | int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base, |
1079 | size_t vram_size) |
1080 | { |
1081 | struct drm_vram_mm *vram_mm; |
1082 | |
1083 | if (drm_WARN_ON_ONCE(dev, dev->vram_mm)) |
1084 | return 0; |
1085 | |
1086 | vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size); |
1087 | if (IS_ERR(ptr: vram_mm)) |
1088 | return PTR_ERR(ptr: vram_mm); |
1089 | return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL); |
1090 | } |
1091 | EXPORT_SYMBOL(drmm_vram_helper_init); |
1092 | |
1093 | /* |
1094 | * Mode-config helpers |
1095 | */ |
1096 | |
1097 | static enum drm_mode_status |
1098 | drm_vram_helper_mode_valid_internal(struct drm_device *dev, |
1099 | const struct drm_display_mode *mode, |
1100 | unsigned long max_bpp) |
1101 | { |
1102 | struct drm_vram_mm *vmm = dev->vram_mm; |
1103 | unsigned long fbsize, fbpages, max_fbpages; |
1104 | |
1105 | if (WARN_ON(!dev->vram_mm)) |
1106 | return MODE_BAD; |
1107 | |
1108 | max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT; |
1109 | |
1110 | fbsize = mode->hdisplay * mode->vdisplay * max_bpp; |
1111 | fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE); |
1112 | |
1113 | if (fbpages > max_fbpages) |
1114 | return MODE_MEM; |
1115 | |
1116 | return MODE_OK; |
1117 | } |
1118 | |
1119 | /** |
1120 | * drm_vram_helper_mode_valid - Tests if a display mode's |
1121 | * framebuffer fits into the available video memory. |
1122 | * @dev: the DRM device |
1123 | * @mode: the mode to test |
1124 | * |
1125 | * This function tests if enough video memory is available for using the |
1126 | * specified display mode. Atomic modesetting requires importing the |
1127 | * designated framebuffer into video memory before evicting the active |
1128 | * one. Hence, any framebuffer may consume at most half of the available |
1129 | * VRAM. Display modes that require a larger framebuffer can not be used, |
1130 | * even if the CRTC does support them. Each framebuffer is assumed to |
1131 | * have 32-bit color depth. |
1132 | * |
1133 | * Note: |
1134 | * The function can only test if the display mode is supported in |
1135 | * general. If there are too many framebuffers pinned to video memory, |
1136 | * a display mode may still not be usable in practice. The color depth of |
1137 | * 32-bit fits all current use case. A more flexible test can be added |
1138 | * when necessary. |
1139 | * |
1140 | * Returns: |
1141 | * MODE_OK if the display mode is supported, or an error code of type |
1142 | * enum drm_mode_status otherwise. |
1143 | */ |
1144 | enum drm_mode_status |
1145 | drm_vram_helper_mode_valid(struct drm_device *dev, |
1146 | const struct drm_display_mode *mode) |
1147 | { |
1148 | static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */ |
1149 | |
1150 | return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp); |
1151 | } |
1152 | EXPORT_SYMBOL(drm_vram_helper_mode_valid); |
1153 | |
1154 | MODULE_DESCRIPTION("DRM VRAM memory-management helpers" ); |
1155 | MODULE_LICENSE("GPL" ); |
1156 | |