exynos_drm_gem.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/* exynos_drm_gem.c
  3 *
  4 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
  5 * Author: Inki Dae <inki.dae@samsung.com>
  6 */
  7
  8
  9#include <linux/dma-buf.h>
 10#include <linux/shmem_fs.h>
 11#include <linux/module.h>
 12
 13#include <drm/drm_dumb_buffers.h>
 14#include <drm/drm_prime.h>
 15#include <drm/drm_print.h>
 16#include <drm/drm_vma_manager.h>
 17#include <drm/exynos_drm.h>
 18
 19#include "exynos_drm_drv.h"
 20#include "exynos_drm_gem.h"
 21
 22MODULE_IMPORT_NS("DMA_BUF");
 23
 24static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
 25
 26static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem, bool kvmap)
 27{
 28	struct drm_device *dev = exynos_gem->base.dev;
 29	unsigned long attr = 0;
 30
 31	if (exynos_gem->dma_addr) {
 32		DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "already allocated.\n");
 33		return 0;
 34	}
 35
 36	/*
 37	 * if EXYNOS_BO_CONTIG, fully physically contiguous memory
 38	 * region will be allocated else physically contiguous
 39	 * as possible.
 40	 */
 41	if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
 42		attr |= DMA_ATTR_FORCE_CONTIGUOUS;
 43
 44	/*
 45	 * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
 46	 * else cachable mapping.
 47	 */
 48	if (exynos_gem->flags & EXYNOS_BO_WC ||
 49			!(exynos_gem->flags & EXYNOS_BO_CACHABLE))
 50		attr |= DMA_ATTR_WRITE_COMBINE;
 51
 52	/* FBDev emulation requires kernel mapping */
 53	if (!kvmap)
 54		attr |= DMA_ATTR_NO_KERNEL_MAPPING;
 55
 56	exynos_gem->dma_attrs = attr;
 57	exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
 58					     &exynos_gem->dma_addr, GFP_KERNEL,
 59					     exynos_gem->dma_attrs);
 60	if (!exynos_gem->cookie) {
 61		DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate buffer.\n");
 62		return -ENOMEM;
 63	}
 64
 65	if (kvmap)
 66		exynos_gem->kvaddr = exynos_gem->cookie;
 67
 68	DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "dma_addr(0x%lx), size(0x%lx)\n",
 69			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
 70	return 0;
 71}
 72
 73static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
 74{
 75	struct drm_device *dev = exynos_gem->base.dev;
 76
 77	if (!exynos_gem->dma_addr) {
 78		DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr is invalid.\n");
 79		return;
 80	}
 81
 82	DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr(0x%lx), size(0x%lx)\n",
 83			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
 84
 85	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
 86			(dma_addr_t)exynos_gem->dma_addr,
 87			exynos_gem->dma_attrs);
 88}
 89
 90static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
 91					struct drm_file *file_priv,
 92					unsigned int *handle)
 93{
 94	int ret;
 95
 96	/*
 97	 * allocate a id of idr table where the obj is registered
 98	 * and handle has the id what user can see.
 99	 */
100	ret = drm_gem_handle_create(file_priv, obj, handle);
101	if (ret)
102		return ret;
103
104	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "gem handle = 0x%x\n", *handle);
105
106	/* drop reference from allocate - handle holds it now. */
107	drm_gem_object_put(obj);
108
109	return 0;
110}
111
112void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem)
113{
114	struct drm_gem_object *obj = &exynos_gem->base;
115
116	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "handle count = %d\n",
117			  obj->handle_count);
118
119	/*
120	 * do not release memory region from exporter.
121	 *
122	 * the region will be released by exporter
123	 * once dmabuf's refcount becomes 0.
124	 */
125	if (obj->import_attach)
126		drm_prime_gem_destroy(obj, exynos_gem->sgt);
127	else
128		exynos_drm_free_buf(exynos_gem);
129
130	/* release file pointer to gem object. */
131	drm_gem_object_release(obj);
132
133	kfree(exynos_gem);
134}
135
136static const struct vm_operations_struct exynos_drm_gem_vm_ops = {
137	.open = drm_gem_vm_open,
138	.close = drm_gem_vm_close,
139};
140
141static const struct drm_gem_object_funcs exynos_drm_gem_object_funcs = {
142	.free = exynos_drm_gem_free_object,
143	.get_sg_table = exynos_drm_gem_prime_get_sg_table,
144	.mmap = exynos_drm_gem_mmap,
145	.vm_ops = &exynos_drm_gem_vm_ops,
146};
147
148static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
149						  unsigned long size)
150{
151	struct exynos_drm_gem *exynos_gem;
152	struct drm_gem_object *obj;
153	int ret;
154
155	exynos_gem = kzalloc(sizeof(*exynos_gem), GFP_KERNEL);
156	if (!exynos_gem)
157		return ERR_PTR(-ENOMEM);
158
159	exynos_gem->size = size;
160	obj = &exynos_gem->base;
161
162	obj->funcs = &exynos_drm_gem_object_funcs;
163
164	ret = drm_gem_object_init(dev, obj, size);
165	if (ret < 0) {
166		DRM_DEV_ERROR(dev->dev, "failed to initialize gem object\n");
167		kfree(exynos_gem);
168		return ERR_PTR(ret);
169	}
170
171	ret = drm_gem_create_mmap_offset(obj);
172	if (ret < 0) {
173		drm_gem_object_release(obj);
174		kfree(exynos_gem);
175		return ERR_PTR(ret);
176	}
177
178	DRM_DEV_DEBUG_KMS(dev->dev, "created file object = %p\n", obj->filp);
179
180	return exynos_gem;
181}
182
183struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
184					     unsigned int flags,
185					     unsigned long size,
186					     bool kvmap)
187{
188	struct exynos_drm_gem *exynos_gem;
189	int ret;
190
191	if (flags & ~(EXYNOS_BO_MASK)) {
192		DRM_DEV_ERROR(dev->dev,
193			      "invalid GEM buffer flags: %u\n", flags);
194		return ERR_PTR(-EINVAL);
195	}
196
197	if (!size) {
198		DRM_DEV_ERROR(dev->dev, "invalid GEM buffer size: %lu\n", size);
199		return ERR_PTR(-EINVAL);
200	}
201
202	size = roundup(size, PAGE_SIZE);
203
204	exynos_gem = exynos_drm_gem_init(dev, size);
205	if (IS_ERR(exynos_gem))
206		return exynos_gem;
207
208	if (!is_drm_iommu_supported(dev) && (flags & EXYNOS_BO_NONCONTIG)) {
209		/*
210		 * when no IOMMU is available, all allocated buffers are
211		 * contiguous anyway, so drop EXYNOS_BO_NONCONTIG flag
212		 */
213		flags &= ~EXYNOS_BO_NONCONTIG;
214		DRM_WARN("Non-contiguous allocation is not supported without IOMMU, falling back to contiguous buffer\n");
215	}
216
217	/* set memory type and cache attribute from user side. */
218	exynos_gem->flags = flags;
219
220	ret = exynos_drm_alloc_buf(exynos_gem, kvmap);
221	if (ret < 0) {
222		drm_gem_object_release(&exynos_gem->base);
223		kfree(exynos_gem);
224		return ERR_PTR(ret);
225	}
226
227	return exynos_gem;
228}
229
230int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
231				struct drm_file *file_priv)
232{
233	struct drm_exynos_gem_create *args = data;
234	struct exynos_drm_gem *exynos_gem;
235	int ret;
236
237	exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size, false);
238	if (IS_ERR(exynos_gem))
239		return PTR_ERR(exynos_gem);
240
241	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
242					   &args->handle);
243	if (ret) {
244		exynos_drm_gem_destroy(exynos_gem);
245		return ret;
246	}
247
248	return 0;
249}
250
251int exynos_drm_gem_map_ioctl(struct drm_device *dev, void *data,
252			     struct drm_file *file_priv)
253{
254	struct drm_exynos_gem_map *args = data;
255
256	return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
257				       &args->offset);
258}
259
260struct exynos_drm_gem *exynos_drm_gem_get(struct drm_file *filp,
261					  unsigned int gem_handle)
262{
263	struct drm_gem_object *obj;
264
265	obj = drm_gem_object_lookup(filp, gem_handle);
266	if (!obj)
267		return NULL;
268	return to_exynos_gem(obj);
269}
270
271static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
272				      struct vm_area_struct *vma)
273{
274	struct drm_device *drm_dev = exynos_gem->base.dev;
275	unsigned long vm_size;
276	int ret;
277
278	vm_flags_clear(vma, VM_PFNMAP);
279	vma->vm_pgoff = 0;
280
281	vm_size = vma->vm_end - vma->vm_start;
282
283	/* check if user-requested size is valid. */
284	if (vm_size > exynos_gem->size)
285		return -EINVAL;
286
287	ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
288			     exynos_gem->dma_addr, exynos_gem->size,
289			     exynos_gem->dma_attrs);
290	if (ret < 0) {
291		DRM_ERROR("failed to mmap.\n");
292		return ret;
293	}
294
295	return 0;
296}
297
298int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
299				      struct drm_file *file_priv)
300{
301	struct exynos_drm_gem *exynos_gem;
302	struct drm_exynos_gem_info *args = data;
303	struct drm_gem_object *obj;
304
305	obj = drm_gem_object_lookup(file_priv, args->handle);
306	if (!obj) {
307		DRM_DEV_ERROR(dev->dev, "failed to lookup gem object.\n");
308		return -EINVAL;
309	}
310
311	exynos_gem = to_exynos_gem(obj);
312
313	args->flags = exynos_gem->flags;
314	args->size = exynos_gem->size;
315
316	drm_gem_object_put(obj);
317
318	return 0;
319}
320
321void exynos_drm_gem_free_object(struct drm_gem_object *obj)
322{
323	exynos_drm_gem_destroy(to_exynos_gem(obj));
324}
325
326int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
327			       struct drm_device *dev,
328			       struct drm_mode_create_dumb *args)
329{
330	struct exynos_drm_gem *exynos_gem;
331	unsigned int flags;
332	int ret;
333
334	ret = drm_mode_size_dumb(dev, args, 0, 0);
335	if (ret)
336		return ret;
337
338	/*
339	 * allocate memory to be used for framebuffer.
340	 * - this callback would be called by user application
341	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
342	 */
343
344	if (is_drm_iommu_supported(dev))
345		flags = EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC;
346	else
347		flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
348
349	exynos_gem = exynos_drm_gem_create(dev, flags, args->size, false);
350	if (IS_ERR(exynos_gem)) {
351		dev_warn(dev->dev, "FB allocation failed.\n");
352		return PTR_ERR(exynos_gem);
353	}
354
355	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
356					   &args->handle);
357	if (ret) {
358		exynos_drm_gem_destroy(exynos_gem);
359		return ret;
360	}
361
362	return 0;
363}
364
365static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
366{
367	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
368	int ret;
369
370	if (obj->import_attach)
371		return dma_buf_mmap(obj->dma_buf, vma, 0);
372
373	vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
374
375	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "flags = 0x%x\n",
376			  exynos_gem->flags);
377
378	/* non-cachable as default. */
379	if (exynos_gem->flags & EXYNOS_BO_CACHABLE)
380		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
381	else if (exynos_gem->flags & EXYNOS_BO_WC)
382		vma->vm_page_prot =
383			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
384	else
385		vma->vm_page_prot =
386			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
387
388	ret = exynos_drm_gem_mmap_buffer(exynos_gem, vma);
389	if (ret)
390		goto err_close_vm;
391
392	return ret;
393
394err_close_vm:
395	drm_gem_vm_close(vma);
396
397	return ret;
398}
399
400/* low-level interface prime helpers */
401struct drm_gem_object *exynos_drm_gem_prime_import(struct drm_device *dev,
402					    struct dma_buf *dma_buf)
403{
404	return drm_gem_prime_import_dev(dev, dma_buf, to_dma_dev(dev));
405}
406
407struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
408{
409	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
410	struct drm_device *drm_dev = obj->dev;
411	struct sg_table *sgt;
412	int ret;
413
414	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
415	if (!sgt)
416		return ERR_PTR(-ENOMEM);
417
418	ret = dma_get_sgtable_attrs(to_dma_dev(drm_dev), sgt, exynos_gem->cookie,
419				    exynos_gem->dma_addr, exynos_gem->size,
420				    exynos_gem->dma_attrs);
421	if (ret) {
422		DRM_ERROR("failed to get sgtable, %d\n", ret);
423		kfree(sgt);
424		return ERR_PTR(ret);
425	}
426
427	return sgt;
428}
429
430struct drm_gem_object *
431exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
432				     struct dma_buf_attachment *attach,
433				     struct sg_table *sgt)
434{
435	struct exynos_drm_gem *exynos_gem;
436
437	/* check if the entries in the sg_table are contiguous */
438	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
439		DRM_ERROR("buffer chunks must be mapped contiguously");
440		return ERR_PTR(-EINVAL);
441	}
442
443	exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
444	if (IS_ERR(exynos_gem))
445		return ERR_CAST(exynos_gem);
446
447	/*
448	 * Buffer has been mapped as contiguous into DMA address space,
449	 * but if there is IOMMU, it can be either CONTIG or NONCONTIG.
450	 * We assume a simplified logic below:
451	 */
452	if (is_drm_iommu_supported(dev))
453		exynos_gem->flags |= EXYNOS_BO_NONCONTIG;
454	else
455		exynos_gem->flags |= EXYNOS_BO_CONTIG;
456
457	exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
458	exynos_gem->sgt = sgt;
459	return &exynos_gem->base;
460}