1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/ 4 * Author: Rob Clark <rob.clark@linaro.org> 5 */ 6 7 #include <linux/dma-buf.h> 8 #include <linux/highmem.h> 9 10 #include <drm/drm_prime.h> 11 12 #include "omap_drv.h" 13 14 /* ----------------------------------------------------------------------------- 15 * DMABUF Export 16 */ 17 18 static struct sg_table *omap_gem_map_dma_buf( 19 struct dma_buf_attachment *attachment, 20 enum dma_data_direction dir) 21 { 22 struct drm_gem_object *obj = attachment->dmabuf->priv; 23 struct sg_table *sg; 24 dma_addr_t dma_addr; 25 int ret; 26 27 sg = kzalloc(sizeof(*sg), GFP_KERNEL); 28 if (!sg) 29 return ERR_PTR(-ENOMEM); 30 31 /* camera, etc, need physically contiguous.. but we need a 32 * better way to know this.. 33 */ 34 ret = omap_gem_pin(obj, &dma_addr); 35 if (ret) 36 goto out; 37 38 ret = sg_alloc_table(sg, 1, GFP_KERNEL); 39 if (ret) 40 goto out; 41 42 sg_init_table(sg->sgl, 1); 43 sg_dma_len(sg->sgl) = obj->size; 44 sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0); 45 sg_dma_address(sg->sgl) = dma_addr; 46 47 /* this must be after omap_gem_pin() to ensure we have pages attached */ 48 omap_gem_dma_sync_buffer(obj, dir); 49 50 return sg; 51 out: 52 kfree(sg); 53 return ERR_PTR(ret); 54 } 55 56 static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, 57 struct sg_table *sg, enum dma_data_direction dir) 58 { 59 struct drm_gem_object *obj = attachment->dmabuf->priv; 60 omap_gem_unpin(obj); 61 sg_free_table(sg); 62 kfree(sg); 63 } 64 65 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer, 66 enum dma_data_direction dir) 67 { 68 struct drm_gem_object *obj = buffer->priv; 69 struct page **pages; 70 if (omap_gem_flags(obj) & OMAP_BO_TILED_MASK) { 71 /* TODO we would need to pin at least part of the buffer to 72 * get de-tiled view. For now just reject it. 73 */ 74 return -ENOMEM; 75 } 76 /* make sure we have the pages: */ 77 return omap_gem_get_pages(obj, &pages, true); 78 } 79 80 static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer, 81 enum dma_data_direction dir) 82 { 83 struct drm_gem_object *obj = buffer->priv; 84 omap_gem_put_pages(obj); 85 return 0; 86 } 87 88 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer, 89 struct vm_area_struct *vma) 90 { 91 struct drm_gem_object *obj = buffer->priv; 92 int ret = 0; 93 94 ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma); 95 if (ret < 0) 96 return ret; 97 98 return omap_gem_mmap_obj(obj, vma); 99 } 100 101 static const struct dma_buf_ops omap_dmabuf_ops = { 102 .map_dma_buf = omap_gem_map_dma_buf, 103 .unmap_dma_buf = omap_gem_unmap_dma_buf, 104 .release = drm_gem_dmabuf_release, 105 .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access, 106 .end_cpu_access = omap_gem_dmabuf_end_cpu_access, 107 .mmap = omap_gem_dmabuf_mmap, 108 }; 109 110 struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags) 111 { 112 DEFINE_DMA_BUF_EXPORT_INFO(exp_info); 113 114 exp_info.ops = &omap_dmabuf_ops; 115 exp_info.size = obj->size; 116 exp_info.flags = flags; 117 exp_info.priv = obj; 118 119 return drm_gem_dmabuf_export(obj->dev, &exp_info); 120 } 121 122 /* ----------------------------------------------------------------------------- 123 * DMABUF Import 124 */ 125 126 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, 127 struct dma_buf *dma_buf) 128 { 129 struct dma_buf_attachment *attach; 130 struct drm_gem_object *obj; 131 struct sg_table *sgt; 132 int ret; 133 134 if (dma_buf->ops == &omap_dmabuf_ops) { 135 obj = dma_buf->priv; 136 if (obj->dev == dev) { 137 /* 138 * Importing dmabuf exported from out own gem increases 139 * refcount on gem itself instead of f_count of dmabuf. 140 */ 141 drm_gem_object_get(obj); 142 return obj; 143 } 144 } 145 146 attach = dma_buf_attach(dma_buf, dev->dev); 147 if (IS_ERR(attach)) 148 return ERR_CAST(attach); 149 150 get_dma_buf(dma_buf); 151 152 sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE); 153 if (IS_ERR(sgt)) { 154 ret = PTR_ERR(sgt); 155 goto fail_detach; 156 } 157 158 obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt); 159 if (IS_ERR(obj)) { 160 ret = PTR_ERR(obj); 161 goto fail_unmap; 162 } 163 164 obj->import_attach = attach; 165 166 return obj; 167 168 fail_unmap: 169 dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE); 170 fail_detach: 171 dma_buf_detach(dma_buf, attach); 172 dma_buf_put(dma_buf); 173 174 return ERR_PTR(ret); 175 } 176