drm/mediatek/mtk_drm_gem.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (c) 2015 MediaTek Inc.
0004  */
0005
0006 #include <linux/dma-buf.h>
0007
0008 #include <drm/drm.h>
0009 #include <drm/drm_device.h>
0010 #include <drm/drm_gem.h>
0011 #include <drm/drm_gem_cma_helper.h>
0012 #include <drm/drm_prime.h>
0013
0014 #include "mtk_drm_drv.h"
0015 #include "mtk_drm_gem.h"
0016
0017 static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
0018
0019 static const struct drm_gem_object_funcs mtk_drm_gem_object_funcs = {
0020     .free = mtk_drm_gem_free_object,
0021     .get_sg_table = mtk_gem_prime_get_sg_table,
0022     .vmap = mtk_drm_gem_prime_vmap,
0023     .vunmap = mtk_drm_gem_prime_vunmap,
0024     .mmap = mtk_drm_gem_object_mmap,
0025     .vm_ops = &drm_gem_cma_vm_ops,
0026 };
0027
0028 static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,
0029                         unsigned long size)
0030 {
0031     struct mtk_drm_gem_obj *mtk_gem_obj;
0032     int ret;
0033
0034     size = round_up(size, PAGE_SIZE);
0035
0036     mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
0037     if (!mtk_gem_obj)
0038         return ERR_PTR(-ENOMEM);
0039
0040     mtk_gem_obj->base.funcs = &mtk_drm_gem_object_funcs;
0041
0042     ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
0043     if (ret < 0) {
0044         DRM_ERROR("failed to initialize gem object\n");
0045         kfree(mtk_gem_obj);
0046         return ERR_PTR(ret);
0047     }
0048
0049     return mtk_gem_obj;
0050 }
0051
0052 struct mtk_drm_gem_obj *mtk_drm_gem_create(struct drm_device *dev,
0053                        size_t size, bool alloc_kmap)
0054 {
0055     struct mtk_drm_private *priv = dev->dev_private;
0056     struct mtk_drm_gem_obj *mtk_gem;
0057     struct drm_gem_object *obj;
0058     int ret;
0059
0060     mtk_gem = mtk_drm_gem_init(dev, size);
0061     if (IS_ERR(mtk_gem))
0062         return ERR_CAST(mtk_gem);
0063
0064     obj = &mtk_gem->base;
0065
0066     mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE;
0067
0068     if (!alloc_kmap)
0069         mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
0070
0071     mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size,
0072                       &mtk_gem->dma_addr, GFP_KERNEL,
0073                       mtk_gem->dma_attrs);
0074     if (!mtk_gem->cookie) {
0075         DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size);
0076         ret = -ENOMEM;
0077         goto err_gem_free;
0078     }
0079
0080     if (alloc_kmap)
0081         mtk_gem->kvaddr = mtk_gem->cookie;
0082
0083     DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n",
0084              mtk_gem->cookie, &mtk_gem->dma_addr,
0085              size);
0086
0087     return mtk_gem;
0088
0089 err_gem_free:
0090     drm_gem_object_release(obj);
0091     kfree(mtk_gem);
0092     return ERR_PTR(ret);
0093 }
0094
0095 void mtk_drm_gem_free_object(struct drm_gem_object *obj)
0096 {
0097     struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
0098     struct mtk_drm_private *priv = obj->dev->dev_private;
0099
0100     if (mtk_gem->sg)
0101         drm_prime_gem_destroy(obj, mtk_gem->sg);
0102     else
0103         dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie,
0104                    mtk_gem->dma_addr, mtk_gem->dma_attrs);
0105
0106     /* release file pointer to gem object. */
0107     drm_gem_object_release(obj);
0108
0109     kfree(mtk_gem);
0110 }
0111
0112 int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
0113                 struct drm_mode_create_dumb *args)
0114 {
0115     struct mtk_drm_gem_obj *mtk_gem;
0116     int ret;
0117
0118     args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
0119     args->size = args->pitch * args->height;
0120
0121     mtk_gem = mtk_drm_gem_create(dev, args->size, false);
0122     if (IS_ERR(mtk_gem))
0123         return PTR_ERR(mtk_gem);
0124
0125     /*
0126      * allocate a id of idr table where the obj is registered
0127      * and handle has the id what user can see.
0128      */
0129     ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
0130     if (ret)
0131         goto err_handle_create;
0132
0133     /* drop reference from allocate - handle holds it now. */
0134     drm_gem_object_put(&mtk_gem->base);
0135
0136     return 0;
0137
0138 err_handle_create:
0139     mtk_drm_gem_free_object(&mtk_gem->base);
0140     return ret;
0141 }
0142
0143 static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj,
0144                    struct vm_area_struct *vma)
0145
0146 {
0147     int ret;
0148     struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
0149     struct mtk_drm_private *priv = obj->dev->dev_private;
0150
0151     /*
0152      * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
0153      * whole buffer from the start.
0154      */
0155     vma->vm_pgoff = 0;
0156
0157     /*
0158      * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear
0159      * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
0160      */
0161     vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
0162     vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
0163     vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
0164
0165     ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie,
0166                  mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs);
0167     if (ret)
0168         drm_gem_vm_close(vma);
0169
0170     return ret;
0171 }
0172
0173 /*
0174  * Allocate a sg_table for this GEM object.
0175  * Note: Both the table's contents, and the sg_table itself must be freed by
0176  *       the caller.
0177  * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
0178  */
0179 struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj)
0180 {
0181     struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
0182     struct mtk_drm_private *priv = obj->dev->dev_private;
0183     struct sg_table *sgt;
0184     int ret;
0185
0186     sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
0187     if (!sgt)
0188         return ERR_PTR(-ENOMEM);
0189
0190     ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie,
0191                     mtk_gem->dma_addr, obj->size,
0192                     mtk_gem->dma_attrs);
0193     if (ret) {
0194         DRM_ERROR("failed to allocate sgt, %d\n", ret);
0195         kfree(sgt);
0196         return ERR_PTR(ret);
0197     }
0198
0199     return sgt;
0200 }
0201
0202 struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
0203             struct dma_buf_attachment *attach, struct sg_table *sg)
0204 {
0205     struct mtk_drm_gem_obj *mtk_gem;
0206
0207     /* check if the entries in the sg_table are contiguous */
0208     if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
0209         DRM_ERROR("sg_table is not contiguous");
0210         return ERR_PTR(-EINVAL);
0211     }
0212
0213     mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
0214     if (IS_ERR(mtk_gem))
0215         return ERR_CAST(mtk_gem);
0216
0217     mtk_gem->dma_addr = sg_dma_address(sg->sgl);
0218     mtk_gem->sg = sg;
0219
0220     return &mtk_gem->base;
0221 }
0222
0223 int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
0224 {
0225     struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
0226     struct sg_table *sgt = NULL;
0227     unsigned int npages;
0228
0229     if (mtk_gem->kvaddr)
0230         goto out;
0231
0232     sgt = mtk_gem_prime_get_sg_table(obj);
0233     if (IS_ERR(sgt))
0234         return PTR_ERR(sgt);
0235
0236     npages = obj->size >> PAGE_SHIFT;
0237     mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
0238     if (!mtk_gem->pages) {
0239         kfree(sgt);
0240         return -ENOMEM;
0241     }
0242
0243     drm_prime_sg_to_page_array(sgt, mtk_gem->pages, npages);
0244
0245     mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
0246                    pgprot_writecombine(PAGE_KERNEL));
0247
0248 out:
0249     kfree(sgt);
0250     iosys_map_set_vaddr(map, mtk_gem->kvaddr);
0251
0252     return 0;
0253 }
0254
0255 void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj,
0256                   struct iosys_map *map)
0257 {
0258     struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
0259     void *vaddr = map->vaddr;
0260
0261     if (!mtk_gem->pages)
0262         return;
0263
0264     vunmap(vaddr);
0265     mtk_gem->kvaddr = 0;
0266     kfree(mtk_gem->pages);
0267 }