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/pfn_t.h>
 11#include <linux/shmem_fs.h>
 12
 13#include <drm/drm_prime.h>
 14#include <drm/drm_vma_manager.h>
 15#include <drm/exynos_drm.h>
 16
 17#include "exynos_drm_drv.h"
 18#include "exynos_drm_gem.h"
 19
 20static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem, bool kvmap)
 21{
 22	struct drm_device *dev = exynos_gem->base.dev;
 23	unsigned long attr = 0;
 24
 25	if (exynos_gem->dma_addr) {
 26		DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "already allocated.\n");
 27		return 0;
 28	}
 29
 30	/*
 31	 * if EXYNOS_BO_CONTIG, fully physically contiguous memory
 32	 * region will be allocated else physically contiguous
 33	 * as possible.
 34	 */
 35	if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
 36		attr |= DMA_ATTR_FORCE_CONTIGUOUS;
 37
 38	/*
 39	 * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
 40	 * else cachable mapping.
 41	 */
 42	if (exynos_gem->flags & EXYNOS_BO_WC ||
 43			!(exynos_gem->flags & EXYNOS_BO_CACHABLE))
 44		attr |= DMA_ATTR_WRITE_COMBINE;
 45
 46	/* FBDev emulation requires kernel mapping */
 47	if (!kvmap)
 48		attr |= DMA_ATTR_NO_KERNEL_MAPPING;
 49
 50	exynos_gem->dma_attrs = attr;
 51	exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
 52					     &exynos_gem->dma_addr, GFP_KERNEL,
 53					     exynos_gem->dma_attrs);
 54	if (!exynos_gem->cookie) {
 55		DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate buffer.\n");
 56		return -ENOMEM;
 57	}
 58
 59	if (kvmap)
 60		exynos_gem->kvaddr = exynos_gem->cookie;
 61
 62	DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "dma_addr(0x%lx), size(0x%lx)\n",
 63			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
 64	return 0;
 65}
 66
 67static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
 68{
 69	struct drm_device *dev = exynos_gem->base.dev;
 70
 71	if (!exynos_gem->dma_addr) {
 72		DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr is invalid.\n");
 73		return;
 74	}
 75
 76	DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr(0x%lx), size(0x%lx)\n",
 77			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
 78
 79	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
 80			(dma_addr_t)exynos_gem->dma_addr,
 81			exynos_gem->dma_attrs);
 82}
 83
 84static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
 85					struct drm_file *file_priv,
 86					unsigned int *handle)
 87{
 88	int ret;
 89
 90	/*
 91	 * allocate a id of idr table where the obj is registered
 92	 * and handle has the id what user can see.
 93	 */
 94	ret = drm_gem_handle_create(file_priv, obj, handle);
 95	if (ret)
 96		return ret;
 97
 98	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "gem handle = 0x%x\n", *handle);
 99
100	/* drop reference from allocate - handle holds it now. */
101	drm_gem_object_put(obj);
102
103	return 0;
104}
105
106void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem)
107{
108	struct drm_gem_object *obj = &exynos_gem->base;
109
110	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "handle count = %d\n",
111			  obj->handle_count);
112
113	/*
114	 * do not release memory region from exporter.
115	 *
116	 * the region will be released by exporter
117	 * once dmabuf's refcount becomes 0.
118	 */
119	if (obj->import_attach)
120		drm_prime_gem_destroy(obj, exynos_gem->sgt);
121	else
122		exynos_drm_free_buf(exynos_gem);
123
124	/* release file pointer to gem object. */
125	drm_gem_object_release(obj);
126
127	kfree(exynos_gem);
128}
129
130static const struct vm_operations_struct exynos_drm_gem_vm_ops = {
131	.open = drm_gem_vm_open,
132	.close = drm_gem_vm_close,
133};
134
135static const struct drm_gem_object_funcs exynos_drm_gem_object_funcs = {
136	.free = exynos_drm_gem_free_object,
137	.get_sg_table = exynos_drm_gem_prime_get_sg_table,
138	.vm_ops = &exynos_drm_gem_vm_ops,
139};
140
141static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
142						  unsigned long size)
143{
144	struct exynos_drm_gem *exynos_gem;
145	struct drm_gem_object *obj;
146	int ret;
147
148	exynos_gem = kzalloc(sizeof(*exynos_gem), GFP_KERNEL);
149	if (!exynos_gem)
150		return ERR_PTR(-ENOMEM);
151
152	exynos_gem->size = size;
153	obj = &exynos_gem->base;
154
155	obj->funcs = &exynos_drm_gem_object_funcs;
156
157	ret = drm_gem_object_init(dev, obj, size);
158	if (ret < 0) {
159		DRM_DEV_ERROR(dev->dev, "failed to initialize gem object\n");
160		kfree(exynos_gem);
161		return ERR_PTR(ret);
162	}
163
164	ret = drm_gem_create_mmap_offset(obj);
165	if (ret < 0) {
166		drm_gem_object_release(obj);
167		kfree(exynos_gem);
168		return ERR_PTR(ret);
169	}
170
171	DRM_DEV_DEBUG_KMS(dev->dev, "created file object = %pK\n", obj->filp);
172
173	return exynos_gem;
174}
175
176struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
177					     unsigned int flags,
178					     unsigned long size,
179					     bool kvmap)
180{
181	struct exynos_drm_gem *exynos_gem;
182	int ret;
183
184	if (flags & ~(EXYNOS_BO_MASK)) {
185		DRM_DEV_ERROR(dev->dev,
186			      "invalid GEM buffer flags: %u\n", flags);
187		return ERR_PTR(-EINVAL);
188	}
189
190	if (!size) {
191		DRM_DEV_ERROR(dev->dev, "invalid GEM buffer size: %lu\n", size);
192		return ERR_PTR(-EINVAL);
193	}
194
195	size = roundup(size, PAGE_SIZE);
196
197	exynos_gem = exynos_drm_gem_init(dev, size);
198	if (IS_ERR(exynos_gem))
199		return exynos_gem;
200
201	if (!is_drm_iommu_supported(dev) && (flags & EXYNOS_BO_NONCONTIG)) {
202		/*
203		 * when no IOMMU is available, all allocated buffers are
204		 * contiguous anyway, so drop EXYNOS_BO_NONCONTIG flag
205		 */
206		flags &= ~EXYNOS_BO_NONCONTIG;
207		DRM_WARN("Non-contiguous allocation is not supported without IOMMU, falling back to contiguous buffer\n");
208	}
209
210	/* set memory type and cache attribute from user side. */
211	exynos_gem->flags = flags;
212
213	ret = exynos_drm_alloc_buf(exynos_gem, kvmap);
214	if (ret < 0) {
215		drm_gem_object_release(&exynos_gem->base);
216		kfree(exynos_gem);
217		return ERR_PTR(ret);
218	}
219
220	return exynos_gem;
221}
222
223int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
224				struct drm_file *file_priv)
225{
226	struct drm_exynos_gem_create *args = data;
227	struct exynos_drm_gem *exynos_gem;
228	int ret;
229
230	exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size, false);
231	if (IS_ERR(exynos_gem))
232		return PTR_ERR(exynos_gem);
233
234	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
235					   &args->handle);
236	if (ret) {
237		exynos_drm_gem_destroy(exynos_gem);
238		return ret;
239	}
240
241	return 0;
242}
243
244int exynos_drm_gem_map_ioctl(struct drm_device *dev, void *data,
245			     struct drm_file *file_priv)
246{
247	struct drm_exynos_gem_map *args = data;
248
249	return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
250				       &args->offset);
251}
252
253struct exynos_drm_gem *exynos_drm_gem_get(struct drm_file *filp,
254					  unsigned int gem_handle)
255{
256	struct drm_gem_object *obj;
257
258	obj = drm_gem_object_lookup(filp, gem_handle);
259	if (!obj)
260		return NULL;
261	return to_exynos_gem(obj);
262}
263
264static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
265				      struct vm_area_struct *vma)
266{
267	struct drm_device *drm_dev = exynos_gem->base.dev;
268	unsigned long vm_size;
269	int ret;
270
271	vma->vm_flags &= ~VM_PFNMAP;
272	vma->vm_pgoff = 0;
273
274	vm_size = vma->vm_end - vma->vm_start;
275
276	/* check if user-requested size is valid. */
277	if (vm_size > exynos_gem->size)
278		return -EINVAL;
279
280	ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
281			     exynos_gem->dma_addr, exynos_gem->size,
282			     exynos_gem->dma_attrs);
283	if (ret < 0) {
284		DRM_ERROR("failed to mmap.\n");
285		return ret;
286	}
287
288	return 0;
289}
290
291int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
292				      struct drm_file *file_priv)
293{
294	struct exynos_drm_gem *exynos_gem;
295	struct drm_exynos_gem_info *args = data;
296	struct drm_gem_object *obj;
297
298	obj = drm_gem_object_lookup(file_priv, args->handle);
299	if (!obj) {
300		DRM_DEV_ERROR(dev->dev, "failed to lookup gem object.\n");
301		return -EINVAL;
302	}
303
304	exynos_gem = to_exynos_gem(obj);
305
306	args->flags = exynos_gem->flags;
307	args->size = exynos_gem->size;
308
309	drm_gem_object_put(obj);
310
311	return 0;
312}
313
314void exynos_drm_gem_free_object(struct drm_gem_object *obj)
315{
316	exynos_drm_gem_destroy(to_exynos_gem(obj));
317}
318
319int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
320			       struct drm_device *dev,
321			       struct drm_mode_create_dumb *args)
322{
323	struct exynos_drm_gem *exynos_gem;
324	unsigned int flags;
325	int ret;
326
327	/*
328	 * allocate memory to be used for framebuffer.
329	 * - this callback would be called by user application
330	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
331	 */
332
333	args->pitch = args->width * ((args->bpp + 7) / 8);
334	args->size = args->pitch * args->height;
335
336	if (is_drm_iommu_supported(dev))
337		flags = EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC;
338	else
339		flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
340
341	exynos_gem = exynos_drm_gem_create(dev, flags, args->size, false);
342	if (IS_ERR(exynos_gem)) {
343		dev_warn(dev->dev, "FB allocation failed.\n");
344		return PTR_ERR(exynos_gem);
345	}
346
347	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
348					   &args->handle);
349	if (ret) {
350		exynos_drm_gem_destroy(exynos_gem);
351		return ret;
352	}
353
354	return 0;
355}
356
357static int exynos_drm_gem_mmap_obj(struct drm_gem_object *obj,
358				   struct vm_area_struct *vma)
359{
360	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
361	int ret;
362
363	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "flags = 0x%x\n",
364			  exynos_gem->flags);
365
366	/* non-cachable as default. */
367	if (exynos_gem->flags & EXYNOS_BO_CACHABLE)
368		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
369	else if (exynos_gem->flags & EXYNOS_BO_WC)
370		vma->vm_page_prot =
371			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
372	else
373		vma->vm_page_prot =
374			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
375
376	ret = exynos_drm_gem_mmap_buffer(exynos_gem, vma);
377	if (ret)
378		goto err_close_vm;
379
380	return ret;
381
382err_close_vm:
383	drm_gem_vm_close(vma);
384
385	return ret;
386}
387
388int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
389{
390	struct drm_gem_object *obj;
391	int ret;
392
393	/* set vm_area_struct. */
394	ret = drm_gem_mmap(filp, vma);
395	if (ret < 0) {
396		DRM_ERROR("failed to mmap.\n");
397		return ret;
398	}
399
400	obj = vma->vm_private_data;
401
402	if (obj->import_attach)
403		return dma_buf_mmap(obj->dma_buf, vma, 0);
404
405	return exynos_drm_gem_mmap_obj(obj, vma);
406}
407
408/* low-level interface prime helpers */
409struct drm_gem_object *exynos_drm_gem_prime_import(struct drm_device *dev,
410					    struct dma_buf *dma_buf)
411{
412	return drm_gem_prime_import_dev(dev, dma_buf, to_dma_dev(dev));
413}
414
415struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
416{
417	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
418	struct drm_device *drm_dev = obj->dev;
419	struct sg_table *sgt;
420	int ret;
421
422	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
423	if (!sgt)
424		return ERR_PTR(-ENOMEM);
425
426	ret = dma_get_sgtable_attrs(to_dma_dev(drm_dev), sgt, exynos_gem->cookie,
427				    exynos_gem->dma_addr, exynos_gem->size,
428				    exynos_gem->dma_attrs);
429	if (ret) {
430		DRM_ERROR("failed to get sgtable, %d\n", ret);
431		kfree(sgt);
432		return ERR_PTR(ret);
433	}
434
435	return sgt;
436}
437
438struct drm_gem_object *
439exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
440				     struct dma_buf_attachment *attach,
441				     struct sg_table *sgt)
442{
443	struct exynos_drm_gem *exynos_gem;
444
445	/* check if the entries in the sg_table are contiguous */
446	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
447		DRM_ERROR("buffer chunks must be mapped contiguously");
448		return ERR_PTR(-EINVAL);
449	}
450
451	exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
452	if (IS_ERR(exynos_gem))
453		return ERR_CAST(exynos_gem);
454
455	/*
456	 * Buffer has been mapped as contiguous into DMA address space,
457	 * but if there is IOMMU, it can be either CONTIG or NONCONTIG.
458	 * We assume a simplified logic below:
459	 */
460	if (is_drm_iommu_supported(dev))
461		exynos_gem->flags |= EXYNOS_BO_NONCONTIG;
462	else
463		exynos_gem->flags |= EXYNOS_BO_CONTIG;
464
465	exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
466	exynos_gem->sgt = sgt;
467	return &exynos_gem->base;
468}
469
470int exynos_drm_gem_prime_mmap(struct drm_gem_object *obj,
471			      struct vm_area_struct *vma)
472{
473	int ret;
474
475	ret = drm_gem_mmap_obj(obj, obj->size, vma);
476	if (ret < 0)
477		return ret;
478
479	return exynos_drm_gem_mmap_obj(obj, vma);
480}