1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2015 MediaTek Inc. 4 */ 5 6 #include <linux/dma-buf.h> 7 #include <linux/vmalloc.h> 8 9 #include <drm/drm.h> 10 #include <drm/drm_device.h> 11 #include <drm/drm_gem.h> 12 #include <drm/drm_gem_dma_helper.h> 13 #include <drm/drm_prime.h> 14 #include <drm/drm_print.h> 15 16 #include "mtk_drm_drv.h" 17 #include "mtk_gem.h" 18 19 static int mtk_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); 20 21 static const struct vm_operations_struct vm_ops = { 22 .open = drm_gem_vm_open, 23 .close = drm_gem_vm_close, 24 }; 25 26 static const struct drm_gem_object_funcs mtk_gem_object_funcs = { 27 .free = mtk_gem_free_object, 28 .get_sg_table = mtk_gem_prime_get_sg_table, 29 .vmap = mtk_gem_prime_vmap, 30 .vunmap = mtk_gem_prime_vunmap, 31 .mmap = mtk_gem_object_mmap, 32 .vm_ops = &vm_ops, 33 }; 34 35 static struct mtk_gem_obj *mtk_gem_init(struct drm_device *dev, 36 unsigned long size) 37 { 38 struct mtk_gem_obj *mtk_gem_obj; 39 int ret; 40 41 size = round_up(size, PAGE_SIZE); 42 43 if (size == 0) 44 return ERR_PTR(-EINVAL); 45 46 mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL); 47 if (!mtk_gem_obj) 48 return ERR_PTR(-ENOMEM); 49 50 mtk_gem_obj->base.funcs = &mtk_gem_object_funcs; 51 52 ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size); 53 if (ret < 0) { 54 DRM_ERROR("failed to initialize gem object\n"); 55 kfree(mtk_gem_obj); 56 return ERR_PTR(ret); 57 } 58 59 return mtk_gem_obj; 60 } 61 62 struct mtk_gem_obj *mtk_gem_create(struct drm_device *dev, 63 size_t size, bool alloc_kmap) 64 { 65 struct mtk_drm_private *priv = dev->dev_private; 66 struct mtk_gem_obj *mtk_gem; 67 struct drm_gem_object *obj; 68 int ret; 69 70 mtk_gem = mtk_gem_init(dev, size); 71 if (IS_ERR(mtk_gem)) 72 return ERR_CAST(mtk_gem); 73 74 obj = &mtk_gem->base; 75 76 mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE; 77 78 if (!alloc_kmap) 79 mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING; 80 81 mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size, 82 &mtk_gem->dma_addr, GFP_KERNEL, 83 mtk_gem->dma_attrs); 84 if (!mtk_gem->cookie) { 85 DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size); 86 ret = -ENOMEM; 87 goto err_gem_free; 88 } 89 90 if (alloc_kmap) 91 mtk_gem->kvaddr = mtk_gem->cookie; 92 93 DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n", 94 mtk_gem->cookie, &mtk_gem->dma_addr, 95 size); 96 97 return mtk_gem; 98 99 err_gem_free: 100 drm_gem_object_release(obj); 101 kfree(mtk_gem); 102 return ERR_PTR(ret); 103 } 104 105 void mtk_gem_free_object(struct drm_gem_object *obj) 106 { 107 struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj); 108 struct mtk_drm_private *priv = obj->dev->dev_private; 109 110 if (mtk_gem->sg) 111 drm_prime_gem_destroy(obj, mtk_gem->sg); 112 else 113 dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie, 114 mtk_gem->dma_addr, mtk_gem->dma_attrs); 115 116 /* release file pointer to gem object. */ 117 drm_gem_object_release(obj); 118 119 kfree(mtk_gem); 120 } 121 122 int mtk_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev, 123 struct drm_mode_create_dumb *args) 124 { 125 struct mtk_gem_obj *mtk_gem; 126 int ret; 127 128 args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8); 129 130 /* 131 * Multiply 2 variables of different types, 132 * for example: args->size = args->spacing * args->height; 133 * may cause coverity issue with unintentional overflow. 134 */ 135 args->size = args->pitch; 136 args->size *= args->height; 137 138 mtk_gem = mtk_gem_create(dev, args->size, false); 139 if (IS_ERR(mtk_gem)) 140 return PTR_ERR(mtk_gem); 141 142 /* 143 * allocate a id of idr table where the obj is registered 144 * and handle has the id what user can see. 145 */ 146 ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle); 147 if (ret) 148 goto err_handle_create; 149 150 /* drop reference from allocate - handle holds it now. */ 151 drm_gem_object_put(&mtk_gem->base); 152 153 return 0; 154 155 err_handle_create: 156 mtk_gem_free_object(&mtk_gem->base); 157 return ret; 158 } 159 160 static int mtk_gem_object_mmap(struct drm_gem_object *obj, 161 struct vm_area_struct *vma) 162 163 { 164 int ret; 165 struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj); 166 struct mtk_drm_private *priv = obj->dev->dev_private; 167 168 /* 169 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the 170 * whole buffer from the start. 171 */ 172 vma->vm_pgoff = 0; 173 174 /* 175 * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear 176 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap(). 177 */ 178 vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP); 179 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); 180 vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); 181 182 ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie, 183 mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs); 184 185 return ret; 186 } 187 188 /* 189 * Allocate a sg_table for this GEM object. 190 * Note: Both the table's contents, and the sg_table itself must be freed by 191 * the caller. 192 * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error. 193 */ 194 struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj) 195 { 196 struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj); 197 struct mtk_drm_private *priv = obj->dev->dev_private; 198 struct sg_table *sgt; 199 int ret; 200 201 sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); 202 if (!sgt) 203 return ERR_PTR(-ENOMEM); 204 205 ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie, 206 mtk_gem->dma_addr, obj->size, 207 mtk_gem->dma_attrs); 208 if (ret) { 209 DRM_ERROR("failed to allocate sgt, %d\n", ret); 210 kfree(sgt); 211 return ERR_PTR(ret); 212 } 213 214 return sgt; 215 } 216 217 struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev, 218 struct dma_buf_attachment *attach, struct sg_table *sg) 219 { 220 struct mtk_gem_obj *mtk_gem; 221 222 /* check if the entries in the sg_table are contiguous */ 223 if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) { 224 DRM_ERROR("sg_table is not contiguous"); 225 return ERR_PTR(-EINVAL); 226 } 227 228 mtk_gem = mtk_gem_init(dev, attach->dmabuf->size); 229 if (IS_ERR(mtk_gem)) 230 return ERR_CAST(mtk_gem); 231 232 mtk_gem->dma_addr = sg_dma_address(sg->sgl); 233 mtk_gem->sg = sg; 234 235 return &mtk_gem->base; 236 } 237 238 int mtk_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map) 239 { 240 struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj); 241 struct sg_table *sgt = NULL; 242 unsigned int npages; 243 244 if (mtk_gem->kvaddr) 245 goto out; 246 247 sgt = mtk_gem_prime_get_sg_table(obj); 248 if (IS_ERR(sgt)) 249 return PTR_ERR(sgt); 250 251 npages = obj->size >> PAGE_SHIFT; 252 mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL); 253 if (!mtk_gem->pages) { 254 sg_free_table(sgt); 255 kfree(sgt); 256 return -ENOMEM; 257 } 258 259 drm_prime_sg_to_page_array(sgt, mtk_gem->pages, npages); 260 261 mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP, 262 pgprot_writecombine(PAGE_KERNEL)); 263 if (!mtk_gem->kvaddr) { 264 sg_free_table(sgt); 265 kfree(sgt); 266 kfree(mtk_gem->pages); 267 return -ENOMEM; 268 } 269 sg_free_table(sgt); 270 kfree(sgt); 271 272 out: 273 iosys_map_set_vaddr(map, mtk_gem->kvaddr); 274 275 return 0; 276 } 277 278 void mtk_gem_prime_vunmap(struct drm_gem_object *obj, struct iosys_map *map) 279 { 280 struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj); 281 void *vaddr = map->vaddr; 282 283 if (!mtk_gem->pages) 284 return; 285 286 vunmap(vaddr); 287 mtk_gem->kvaddr = NULL; 288 kfree(mtk_gem->pages); 289 } 290