1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2012 Russell King
4 */
5
6#include <linux/dma-buf.h>
7#include <linux/dma-mapping.h>
8#include <linux/mman.h>
9#include <linux/shmem_fs.h>
10
11#include <drm/armada_drm.h>
12#include <drm/drm_prime.h>
13
14#include "armada_drm.h"
15#include "armada_gem.h"
16#include "armada_ioctlP.h"
17
18MODULE_IMPORT_NS(DMA_BUF);
19
20static vm_fault_t armada_gem_vm_fault(struct vm_fault *vmf)
21{
22 struct drm_gem_object *gobj = vmf->vma->vm_private_data;
23 struct armada_gem_object *obj = drm_to_armada_gem(gobj);
24 unsigned long pfn = obj->phys_addr >> PAGE_SHIFT;
25
26 pfn += (vmf->address - vmf->vma->vm_start) >> PAGE_SHIFT;
27 return vmf_insert_pfn(vma: vmf->vma, addr: vmf->address, pfn);
28}
29
30static const struct vm_operations_struct armada_gem_vm_ops = {
31 .fault = armada_gem_vm_fault,
32 .open = drm_gem_vm_open,
33 .close = drm_gem_vm_close,
34};
35
36static size_t roundup_gem_size(size_t size)
37{
38 return roundup(size, PAGE_SIZE);
39}
40
41void armada_gem_free_object(struct drm_gem_object *obj)
42{
43 struct armada_gem_object *dobj = drm_to_armada_gem(obj);
44 struct armada_private *priv = drm_to_armada_dev(obj->dev);
45
46 DRM_DEBUG_DRIVER("release obj %p\n", dobj);
47
48 drm_gem_free_mmap_offset(obj: &dobj->obj);
49
50 might_lock(&priv->linear_lock);
51
52 if (dobj->page) {
53 /* page backed memory */
54 unsigned int order = get_order(size: dobj->obj.size);
55 __free_pages(page: dobj->page, order);
56 } else if (dobj->linear) {
57 /* linear backed memory */
58 mutex_lock(&priv->linear_lock);
59 drm_mm_remove_node(node: dobj->linear);
60 mutex_unlock(lock: &priv->linear_lock);
61 kfree(objp: dobj->linear);
62 if (dobj->addr)
63 iounmap(addr: dobj->addr);
64 }
65
66 if (dobj->obj.import_attach) {
67 /* We only ever display imported data */
68 if (dobj->sgt)
69 dma_buf_unmap_attachment_unlocked(attach: dobj->obj.import_attach,
70 sg_table: dobj->sgt, direction: DMA_TO_DEVICE);
71 drm_prime_gem_destroy(obj: &dobj->obj, NULL);
72 }
73
74 drm_gem_object_release(obj: &dobj->obj);
75
76 kfree(objp: dobj);
77}
78
79int
80armada_gem_linear_back(struct drm_device *dev, struct armada_gem_object *obj)
81{
82 struct armada_private *priv = drm_to_armada_dev(dev);
83 size_t size = obj->obj.size;
84
85 if (obj->page || obj->linear)
86 return 0;
87
88 /*
89 * If it is a small allocation (typically cursor, which will
90 * be 32x64 or 64x32 ARGB pixels) try to get it from the system.
91 * Framebuffers will never be this small (our minimum size for
92 * framebuffers is larger than this anyway.) Such objects are
93 * only accessed by the CPU so we don't need any special handing
94 * here.
95 */
96 if (size <= 8192) {
97 unsigned int order = get_order(size);
98 struct page *p = alloc_pages(GFP_KERNEL, order);
99
100 if (p) {
101 obj->addr = page_address(p);
102 obj->phys_addr = page_to_phys(p);
103 obj->page = p;
104
105 memset(obj->addr, 0, PAGE_ALIGN(size));
106 }
107 }
108
109 /*
110 * We could grab something from DMA if it's enabled, but that
111 * involves building in a problem:
112 *
113 * GEM DMA helper interface uses dma_alloc_coherent(), which provides
114 * us with an CPU virtual address and a device address.
115 *
116 * The CPU virtual address may be either an address in the kernel
117 * direct mapped region (for example, as it would be on x86) or
118 * it may be remapped into another part of kernel memory space
119 * (eg, as it would be on ARM.) This means virt_to_phys() on the
120 * returned virtual address is invalid depending on the architecture
121 * implementation.
122 *
123 * The device address may also not be a physical address; it may
124 * be that there is some kind of remapping between the device and
125 * system RAM, which makes the use of the device address also
126 * unsafe to re-use as a physical address.
127 *
128 * This makes DRM usage of dma_alloc_coherent() in a generic way
129 * at best very questionable and unsafe.
130 */
131
132 /* Otherwise, grab it from our linear allocation */
133 if (!obj->page) {
134 struct drm_mm_node *node;
135 unsigned align = min_t(unsigned, size, SZ_2M);
136 void __iomem *ptr;
137 int ret;
138
139 node = kzalloc(size: sizeof(*node), GFP_KERNEL);
140 if (!node)
141 return -ENOSPC;
142
143 mutex_lock(&priv->linear_lock);
144 ret = drm_mm_insert_node_generic(mm: &priv->linear, node,
145 size, alignment: align, color: 0, mode: 0);
146 mutex_unlock(lock: &priv->linear_lock);
147 if (ret) {
148 kfree(objp: node);
149 return ret;
150 }
151
152 obj->linear = node;
153
154 /* Ensure that the memory we're returning is cleared. */
155 ptr = ioremap_wc(offset: obj->linear->start, size);
156 if (!ptr) {
157 mutex_lock(&priv->linear_lock);
158 drm_mm_remove_node(node: obj->linear);
159 mutex_unlock(lock: &priv->linear_lock);
160 kfree(objp: obj->linear);
161 obj->linear = NULL;
162 return -ENOMEM;
163 }
164
165 memset_io(ptr, 0, size);
166 iounmap(addr: ptr);
167
168 obj->phys_addr = obj->linear->start;
169 obj->dev_addr = obj->linear->start;
170 obj->mapped = true;
171 }
172
173 DRM_DEBUG_DRIVER("obj %p phys %#llx dev %#llx\n", obj,
174 (unsigned long long)obj->phys_addr,
175 (unsigned long long)obj->dev_addr);
176
177 return 0;
178}
179
180void *
181armada_gem_map_object(struct drm_device *dev, struct armada_gem_object *dobj)
182{
183 /* only linear objects need to be ioremap'd */
184 if (!dobj->addr && dobj->linear)
185 dobj->addr = ioremap_wc(offset: dobj->phys_addr, size: dobj->obj.size);
186 return dobj->addr;
187}
188
189static const struct drm_gem_object_funcs armada_gem_object_funcs = {
190 .free = armada_gem_free_object,
191 .export = armada_gem_prime_export,
192 .vm_ops = &armada_gem_vm_ops,
193};
194
195struct armada_gem_object *
196armada_gem_alloc_private_object(struct drm_device *dev, size_t size)
197{
198 struct armada_gem_object *obj;
199
200 size = roundup_gem_size(size);
201
202 obj = kzalloc(size: sizeof(*obj), GFP_KERNEL);
203 if (!obj)
204 return NULL;
205
206 obj->obj.funcs = &armada_gem_object_funcs;
207
208 drm_gem_private_object_init(dev, obj: &obj->obj, size);
209
210 DRM_DEBUG_DRIVER("alloc private obj %p size %zu\n", obj, size);
211
212 return obj;
213}
214
215static struct armada_gem_object *armada_gem_alloc_object(struct drm_device *dev,
216 size_t size)
217{
218 struct armada_gem_object *obj;
219 struct address_space *mapping;
220
221 size = roundup_gem_size(size);
222
223 obj = kzalloc(size: sizeof(*obj), GFP_KERNEL);
224 if (!obj)
225 return NULL;
226
227 obj->obj.funcs = &armada_gem_object_funcs;
228
229 if (drm_gem_object_init(dev, obj: &obj->obj, size)) {
230 kfree(objp: obj);
231 return NULL;
232 }
233
234 mapping = obj->obj.filp->f_mapping;
235 mapping_set_gfp_mask(m: mapping, GFP_HIGHUSER | __GFP_RECLAIMABLE);
236
237 DRM_DEBUG_DRIVER("alloc obj %p size %zu\n", obj, size);
238
239 return obj;
240}
241
242/* Dumb alloc support */
243int armada_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
244 struct drm_mode_create_dumb *args)
245{
246 struct armada_gem_object *dobj;
247 u32 handle;
248 size_t size;
249 int ret;
250
251 args->pitch = armada_pitch(width: args->width, bpp: args->bpp);
252 args->size = size = args->pitch * args->height;
253
254 dobj = armada_gem_alloc_private_object(dev, size);
255 if (dobj == NULL)
256 return -ENOMEM;
257
258 ret = armada_gem_linear_back(dev, obj: dobj);
259 if (ret)
260 goto err;
261
262 ret = drm_gem_handle_create(file_priv: file, obj: &dobj->obj, handlep: &handle);
263 if (ret)
264 goto err;
265
266 args->handle = handle;
267
268 /* drop reference from allocate - handle holds it now */
269 DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
270 err:
271 drm_gem_object_put(obj: &dobj->obj);
272 return ret;
273}
274
275/* Private driver gem ioctls */
276int armada_gem_create_ioctl(struct drm_device *dev, void *data,
277 struct drm_file *file)
278{
279 struct drm_armada_gem_create *args = data;
280 struct armada_gem_object *dobj;
281 size_t size;
282 u32 handle;
283 int ret;
284
285 if (args->size == 0)
286 return -ENOMEM;
287
288 size = args->size;
289
290 dobj = armada_gem_alloc_object(dev, size);
291 if (dobj == NULL)
292 return -ENOMEM;
293
294 ret = drm_gem_handle_create(file_priv: file, obj: &dobj->obj, handlep: &handle);
295 if (ret)
296 goto err;
297
298 args->handle = handle;
299
300 /* drop reference from allocate - handle holds it now */
301 DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
302 err:
303 drm_gem_object_put(obj: &dobj->obj);
304 return ret;
305}
306
307/* Map a shmem-backed object into process memory space */
308int armada_gem_mmap_ioctl(struct drm_device *dev, void *data,
309 struct drm_file *file)
310{
311 struct drm_armada_gem_mmap *args = data;
312 struct armada_gem_object *dobj;
313 unsigned long addr;
314
315 dobj = armada_gem_object_lookup(dfile: file, handle: args->handle);
316 if (dobj == NULL)
317 return -ENOENT;
318
319 if (!dobj->obj.filp) {
320 drm_gem_object_put(obj: &dobj->obj);
321 return -EINVAL;
322 }
323
324 addr = vm_mmap(dobj->obj.filp, 0, args->size, PROT_READ | PROT_WRITE,
325 MAP_SHARED, args->offset);
326 drm_gem_object_put(obj: &dobj->obj);
327 if (IS_ERR_VALUE(addr))
328 return addr;
329
330 args->addr = addr;
331
332 return 0;
333}
334
335int armada_gem_pwrite_ioctl(struct drm_device *dev, void *data,
336 struct drm_file *file)
337{
338 struct drm_armada_gem_pwrite *args = data;
339 struct armada_gem_object *dobj;
340 char __user *ptr;
341 int ret = 0;
342
343 DRM_DEBUG_DRIVER("handle %u off %u size %u ptr 0x%llx\n",
344 args->handle, args->offset, args->size, args->ptr);
345
346 if (args->size == 0)
347 return 0;
348
349 ptr = (char __user *)(uintptr_t)args->ptr;
350
351 if (!access_ok(ptr, args->size))
352 return -EFAULT;
353
354 if (fault_in_readable(uaddr: ptr, size: args->size))
355 return -EFAULT;
356
357 dobj = armada_gem_object_lookup(dfile: file, handle: args->handle);
358 if (dobj == NULL)
359 return -ENOENT;
360
361 /* Must be a kernel-mapped object */
362 if (!dobj->addr)
363 return -EINVAL;
364
365 if (args->offset > dobj->obj.size ||
366 args->size > dobj->obj.size - args->offset) {
367 DRM_ERROR("invalid size: object size %u\n", dobj->obj.size);
368 ret = -EINVAL;
369 goto unref;
370 }
371
372 if (copy_from_user(to: dobj->addr + args->offset, from: ptr, n: args->size)) {
373 ret = -EFAULT;
374 } else if (dobj->update) {
375 dobj->update(dobj->update_data);
376 ret = 0;
377 }
378
379 unref:
380 drm_gem_object_put(obj: &dobj->obj);
381 return ret;
382}
383
384/* Prime support */
385static struct sg_table *
386armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
387 enum dma_data_direction dir)
388{
389 struct drm_gem_object *obj = attach->dmabuf->priv;
390 struct armada_gem_object *dobj = drm_to_armada_gem(obj);
391 struct scatterlist *sg;
392 struct sg_table *sgt;
393 int i;
394
395 sgt = kmalloc(size: sizeof(*sgt), GFP_KERNEL);
396 if (!sgt)
397 return NULL;
398
399 if (dobj->obj.filp) {
400 struct address_space *mapping;
401 int count;
402
403 count = dobj->obj.size / PAGE_SIZE;
404 if (sg_alloc_table(sgt, count, GFP_KERNEL))
405 goto free_sgt;
406
407 mapping = dobj->obj.filp->f_mapping;
408
409 for_each_sgtable_sg(sgt, sg, i) {
410 struct page *page;
411
412 page = shmem_read_mapping_page(mapping, index: i);
413 if (IS_ERR(ptr: page))
414 goto release;
415
416 sg_set_page(sg, page, PAGE_SIZE, offset: 0);
417 }
418
419 if (dma_map_sgtable(dev: attach->dev, sgt, dir, attrs: 0))
420 goto release;
421 } else if (dobj->page) {
422 /* Single contiguous page */
423 if (sg_alloc_table(sgt, 1, GFP_KERNEL))
424 goto free_sgt;
425
426 sg_set_page(sg: sgt->sgl, page: dobj->page, len: dobj->obj.size, offset: 0);
427
428 if (dma_map_sgtable(dev: attach->dev, sgt, dir, attrs: 0))
429 goto free_table;
430 } else if (dobj->linear) {
431 /* Single contiguous physical region - no struct page */
432 if (sg_alloc_table(sgt, 1, GFP_KERNEL))
433 goto free_sgt;
434 sg_dma_address(sgt->sgl) = dobj->dev_addr;
435 sg_dma_len(sgt->sgl) = dobj->obj.size;
436 } else {
437 goto free_sgt;
438 }
439 return sgt;
440
441 release:
442 for_each_sgtable_sg(sgt, sg, i)
443 if (sg_page(sg))
444 put_page(page: sg_page(sg));
445 free_table:
446 sg_free_table(sgt);
447 free_sgt:
448 kfree(objp: sgt);
449 return NULL;
450}
451
452static void armada_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
453 struct sg_table *sgt, enum dma_data_direction dir)
454{
455 struct drm_gem_object *obj = attach->dmabuf->priv;
456 struct armada_gem_object *dobj = drm_to_armada_gem(obj);
457 int i;
458
459 if (!dobj->linear)
460 dma_unmap_sgtable(dev: attach->dev, sgt, dir, attrs: 0);
461
462 if (dobj->obj.filp) {
463 struct scatterlist *sg;
464
465 for_each_sgtable_sg(sgt, sg, i)
466 put_page(page: sg_page(sg));
467 }
468
469 sg_free_table(sgt);
470 kfree(objp: sgt);
471}
472
473static int
474armada_gem_dmabuf_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
475{
476 return -EINVAL;
477}
478
479static const struct dma_buf_ops armada_gem_prime_dmabuf_ops = {
480 .map_dma_buf = armada_gem_prime_map_dma_buf,
481 .unmap_dma_buf = armada_gem_prime_unmap_dma_buf,
482 .release = drm_gem_dmabuf_release,
483 .mmap = armada_gem_dmabuf_mmap,
484};
485
486struct dma_buf *
487armada_gem_prime_export(struct drm_gem_object *obj, int flags)
488{
489 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
490
491 exp_info.ops = &armada_gem_prime_dmabuf_ops;
492 exp_info.size = obj->size;
493 exp_info.flags = O_RDWR;
494 exp_info.priv = obj;
495
496 return drm_gem_dmabuf_export(dev: obj->dev, exp_info: &exp_info);
497}
498
499struct drm_gem_object *
500armada_gem_prime_import(struct drm_device *dev, struct dma_buf *buf)
501{
502 struct dma_buf_attachment *attach;
503 struct armada_gem_object *dobj;
504
505 if (buf->ops == &armada_gem_prime_dmabuf_ops) {
506 struct drm_gem_object *obj = buf->priv;
507 if (obj->dev == dev) {
508 /*
509 * Importing our own dmabuf(s) increases the
510 * refcount on the gem object itself.
511 */
512 drm_gem_object_get(obj);
513 return obj;
514 }
515 }
516
517 attach = dma_buf_attach(dmabuf: buf, dev: dev->dev);
518 if (IS_ERR(ptr: attach))
519 return ERR_CAST(ptr: attach);
520
521 dobj = armada_gem_alloc_private_object(dev, size: buf->size);
522 if (!dobj) {
523 dma_buf_detach(dmabuf: buf, attach);
524 return ERR_PTR(error: -ENOMEM);
525 }
526
527 dobj->obj.import_attach = attach;
528 get_dma_buf(dmabuf: buf);
529
530 /*
531 * Don't call dma_buf_map_attachment() here - it maps the
532 * scatterlist immediately for DMA, and this is not always
533 * an appropriate thing to do.
534 */
535 return &dobj->obj;
536}
537
538int armada_gem_map_import(struct armada_gem_object *dobj)
539{
540 int ret;
541
542 dobj->sgt = dma_buf_map_attachment_unlocked(attach: dobj->obj.import_attach,
543 direction: DMA_TO_DEVICE);
544 if (IS_ERR(ptr: dobj->sgt)) {
545 ret = PTR_ERR(ptr: dobj->sgt);
546 dobj->sgt = NULL;
547 DRM_ERROR("dma_buf_map_attachment() error: %d\n", ret);
548 return ret;
549 }
550 if (dobj->sgt->nents > 1) {
551 DRM_ERROR("dma_buf_map_attachment() returned an (unsupported) scattered list\n");
552 return -EINVAL;
553 }
554 if (sg_dma_len(dobj->sgt->sgl) < dobj->obj.size) {
555 DRM_ERROR("dma_buf_map_attachment() returned a small buffer\n");
556 return -EINVAL;
557 }
558 dobj->dev_addr = sg_dma_address(dobj->sgt->sgl);
559 dobj->mapped = true;
560 return 0;
561}
562

source code of linux/drivers/gpu/drm/armada/armada_gem.c