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