// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/ * Author: Rob Clark <rob.clark@linaro.org> */ #include <linux/dma-buf.h> #include <linux/highmem.h> #include <drm/drm_prime.h> #include "omap_drv.h" MODULE_IMPORT_NS(DMA_BUF); /* ----------------------------------------------------------------------------- * DMABUF Export */ static struct sg_table *omap_gem_map_dma_buf( struct dma_buf_attachment *attachment, enum dma_data_direction dir) { struct drm_gem_object *obj = attachment->dmabuf->priv; struct sg_table *sg; dma_addr_t dma_addr; int ret; sg = kzalloc(sizeof(*sg), GFP_KERNEL); if (!sg) return ERR_PTR(-ENOMEM); /* camera, etc, need physically contiguous.. but we need a * better way to know this.. */ ret = omap_gem_pin(obj, &dma_addr); if (ret) goto out; ret = sg_alloc_table(sg, 1, GFP_KERNEL); if (ret) goto out; sg_init_table(sg->sgl, 1); sg_dma_len(sg->sgl) = obj->size; sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0); sg_dma_address(sg->sgl) = dma_addr; /* this must be after omap_gem_pin() to ensure we have pages attached */ omap_gem_dma_sync_buffer(obj, dir); return sg; out: kfree(sg); return ERR_PTR(ret); } static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *sg, enum dma_data_direction dir) { struct drm_gem_object *obj = attachment->dmabuf->priv; omap_gem_unpin(obj); sg_free_table(sg); kfree(sg); } static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer, enum dma_data_direction dir) { struct drm_gem_object *obj = buffer->priv; struct page **pages; if (omap_gem_flags(obj) & OMAP_BO_TILED_MASK) { /* TODO we would need to pin at least part of the buffer to * get de-tiled view. For now just reject it. */ return -ENOMEM; } /* make sure we have the pages: */ return omap_gem_get_pages(obj, &pages, true); } static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer, enum dma_data_direction dir) { struct drm_gem_object *obj = buffer->priv; omap_gem_put_pages(obj); return 0; } static int omap_gem_dmabuf_mmap(struct dma_buf *buffer, struct vm_area_struct *vma) { struct drm_gem_object *obj = buffer->priv; int ret = 0; ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma); if (ret < 0) return ret; return omap_gem_mmap_obj(obj, vma); } static const struct dma_buf_ops omap_dmabuf_ops = { .map_dma_buf = omap_gem_map_dma_buf, .unmap_dma_buf = omap_gem_unmap_dma_buf, .release = drm_gem_dmabuf_release, .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access, .end_cpu_access = omap_gem_dmabuf_end_cpu_access, .mmap = omap_gem_dmabuf_mmap, }; struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags) { DEFINE_DMA_BUF_EXPORT_INFO(exp_info); exp_info.ops = &omap_dmabuf_ops; exp_info.size = obj->size; exp_info.flags = flags; exp_info.priv = obj; return drm_gem_dmabuf_export(obj->dev, &exp_info); } /* ----------------------------------------------------------------------------- * DMABUF Import */ struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, struct dma_buf *dma_buf) { struct dma_buf_attachment *attach; struct drm_gem_object *obj; struct sg_table *sgt; int ret; if (dma_buf->ops == &omap_dmabuf_ops) { obj = dma_buf->priv; if (obj->dev == dev) { /* * Importing dmabuf exported from out own gem increases * refcount on gem itself instead of f_count of dmabuf. */ drm_gem_object_get(obj); return obj; } } attach = dma_buf_attach(dma_buf, dev->dev); if (IS_ERR(attach)) return ERR_CAST(attach); get_dma_buf(dma_buf); sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE); if (IS_ERR(sgt)) { ret = PTR_ERR(sgt); goto fail_detach; } obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt); if (IS_ERR(obj)) { ret = PTR_ERR(obj); goto fail_unmap; } obj->import_attach = attach; return obj; fail_unmap: dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE); fail_detach: dma_buf_detach(dma_buf, attach); dma_buf_put(dma_buf); return ERR_PTR(ret); }