1 // SPDX-License-Identifier: GPL-2.0
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
9 #include <linux/shmem_fs.h>
13 static struct vkms_gem_object *__vkms_gem_create(struct drm_device *dev,
16 struct vkms_gem_object *obj;
19 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
21 return ERR_PTR(-ENOMEM);
23 size = roundup(size, PAGE_SIZE);
24 ret = drm_gem_object_init(dev, &obj->gem, size);
30 mutex_init(&obj->pages_lock);
35 void vkms_gem_free_object(struct drm_gem_object *obj)
37 struct vkms_gem_object *gem = container_of(obj, struct vkms_gem_object,
43 mutex_destroy(&gem->pages_lock);
44 drm_gem_object_release(obj);
48 vm_fault_t vkms_gem_fault(struct vm_fault *vmf)
50 struct vm_area_struct *vma = vmf->vma;
51 struct vkms_gem_object *obj = vma->vm_private_data;
52 unsigned long vaddr = vmf->address;
55 vm_fault_t ret = VM_FAULT_SIGBUS;
57 page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
58 num_pages = DIV_ROUND_UP(obj->gem.size, PAGE_SIZE);
60 if (page_offset > num_pages)
61 return VM_FAULT_SIGBUS;
63 mutex_lock(&obj->pages_lock);
65 get_page(obj->pages[page_offset]);
66 vmf->page = obj->pages[page_offset];
69 mutex_unlock(&obj->pages_lock);
72 struct address_space *mapping;
74 mapping = file_inode(obj->gem.filp)->i_mapping;
75 page = shmem_read_mapping_page(mapping, page_offset);
81 switch (PTR_ERR(page)) {
91 ret = VM_FAULT_SIGBUS;
94 WARN_ON(PTR_ERR(page));
95 ret = VM_FAULT_SIGBUS;
103 struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
104 struct drm_file *file,
108 struct vkms_gem_object *obj;
111 if (!file || !dev || !handle)
112 return ERR_PTR(-EINVAL);
114 obj = __vkms_gem_create(dev, size);
116 return ERR_CAST(obj);
118 ret = drm_gem_handle_create(file, &obj->gem, handle);
119 drm_gem_object_put_unlocked(&obj->gem);
121 drm_gem_object_release(&obj->gem);
129 int vkms_dumb_create(struct drm_file *file, struct drm_device *dev,
130 struct drm_mode_create_dumb *args)
132 struct drm_gem_object *gem_obj;
135 if (!args || !dev || !file)
138 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
139 size = pitch * args->height;
144 gem_obj = vkms_gem_create(dev, file, &args->handle, size);
146 return PTR_ERR(gem_obj);
148 args->size = gem_obj->size;
151 DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
156 int vkms_dumb_map(struct drm_file *file, struct drm_device *dev,
157 u32 handle, u64 *offset)
159 struct drm_gem_object *obj;
162 obj = drm_gem_object_lookup(file, handle);
171 ret = drm_gem_create_mmap_offset(obj);
175 *offset = drm_vma_node_offset_addr(&obj->vma_node);
177 drm_gem_object_put_unlocked(obj);
182 static struct page **_get_pages(struct vkms_gem_object *vkms_obj)
184 struct drm_gem_object *gem_obj = &vkms_obj->gem;
186 if (!vkms_obj->pages) {
187 struct page **pages = drm_gem_get_pages(gem_obj);
192 if (cmpxchg(&vkms_obj->pages, NULL, pages))
193 drm_gem_put_pages(gem_obj, pages, false, true);
196 return vkms_obj->pages;
199 void vkms_gem_vunmap(struct drm_gem_object *obj)
201 struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
203 mutex_lock(&vkms_obj->pages_lock);
204 if (vkms_obj->vmap_count < 1) {
205 WARN_ON(vkms_obj->vaddr);
206 WARN_ON(vkms_obj->pages);
207 mutex_unlock(&vkms_obj->pages_lock);
211 vkms_obj->vmap_count--;
213 if (vkms_obj->vmap_count == 0) {
214 vunmap(vkms_obj->vaddr);
215 vkms_obj->vaddr = NULL;
216 drm_gem_put_pages(obj, vkms_obj->pages, false, true);
217 vkms_obj->pages = NULL;
220 mutex_unlock(&vkms_obj->pages_lock);
223 int vkms_gem_vmap(struct drm_gem_object *obj)
225 struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
228 mutex_lock(&vkms_obj->pages_lock);
230 if (!vkms_obj->vaddr) {
231 unsigned int n_pages = obj->size >> PAGE_SHIFT;
232 struct page **pages = _get_pages(vkms_obj);
235 ret = PTR_ERR(pages);
239 vkms_obj->vaddr = vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
240 if (!vkms_obj->vaddr)
244 vkms_obj->vmap_count++;
249 drm_gem_put_pages(obj, vkms_obj->pages, false, true);
250 vkms_obj->pages = NULL;
252 mutex_unlock(&vkms_obj->pages_lock);