1 /* 2 * drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c 3 * 4 * Copyright (C) 2011 Texas Instruments 5 * Author: Rob Clark <rob.clark@linaro.org> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License version 2 as published by 9 * the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/dma-buf.h> 21 22 #include "omap_drv.h" 23 24 /* ----------------------------------------------------------------------------- 25 * DMABUF Export 26 */ 27 28 static struct sg_table *omap_gem_map_dma_buf( 29 struct dma_buf_attachment *attachment, 30 enum dma_data_direction dir) 31 { 32 struct drm_gem_object *obj = attachment->dmabuf->priv; 33 struct sg_table *sg; 34 dma_addr_t dma_addr; 35 int ret; 36 37 sg = kzalloc(sizeof(*sg), GFP_KERNEL); 38 if (!sg) 39 return ERR_PTR(-ENOMEM); 40 41 /* camera, etc, need physically contiguous.. but we need a 42 * better way to know this.. 43 */ 44 ret = omap_gem_pin(obj, &dma_addr); 45 if (ret) 46 goto out; 47 48 ret = sg_alloc_table(sg, 1, GFP_KERNEL); 49 if (ret) 50 goto out; 51 52 sg_init_table(sg->sgl, 1); 53 sg_dma_len(sg->sgl) = obj->size; 54 sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0); 55 sg_dma_address(sg->sgl) = dma_addr; 56 57 /* this must be after omap_gem_pin() to ensure we have pages attached */ 58 omap_gem_dma_sync_buffer(obj, dir); 59 60 return sg; 61 out: 62 kfree(sg); 63 return ERR_PTR(ret); 64 } 65 66 static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, 67 struct sg_table *sg, enum dma_data_direction dir) 68 { 69 struct drm_gem_object *obj = attachment->dmabuf->priv; 70 omap_gem_unpin(obj); 71 sg_free_table(sg); 72 kfree(sg); 73 } 74 75 static void omap_gem_dmabuf_release(struct dma_buf *buffer) 76 { 77 struct drm_gem_object *obj = buffer->priv; 78 /* release reference that was taken when dmabuf was exported 79 * in omap_gem_prime_set().. 80 */ 81 drm_gem_object_unreference_unlocked(obj); 82 } 83 84 85 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer, 86 enum dma_data_direction dir) 87 { 88 struct drm_gem_object *obj = buffer->priv; 89 struct page **pages; 90 if (omap_gem_flags(obj) & OMAP_BO_TILED) { 91 /* TODO we would need to pin at least part of the buffer to 92 * get de-tiled view. For now just reject it. 93 */ 94 return -ENOMEM; 95 } 96 /* make sure we have the pages: */ 97 return omap_gem_get_pages(obj, &pages, true); 98 } 99 100 static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer, 101 enum dma_data_direction dir) 102 { 103 struct drm_gem_object *obj = buffer->priv; 104 omap_gem_put_pages(obj); 105 return 0; 106 } 107 108 109 static void *omap_gem_dmabuf_kmap_atomic(struct dma_buf *buffer, 110 unsigned long page_num) 111 { 112 struct drm_gem_object *obj = buffer->priv; 113 struct page **pages; 114 omap_gem_get_pages(obj, &pages, false); 115 omap_gem_cpu_sync_page(obj, page_num); 116 return kmap_atomic(pages[page_num]); 117 } 118 119 static void omap_gem_dmabuf_kunmap_atomic(struct dma_buf *buffer, 120 unsigned long page_num, void *addr) 121 { 122 kunmap_atomic(addr); 123 } 124 125 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer, 126 unsigned long page_num) 127 { 128 struct drm_gem_object *obj = buffer->priv; 129 struct page **pages; 130 omap_gem_get_pages(obj, &pages, false); 131 omap_gem_cpu_sync_page(obj, page_num); 132 return kmap(pages[page_num]); 133 } 134 135 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer, 136 unsigned long page_num, void *addr) 137 { 138 struct drm_gem_object *obj = buffer->priv; 139 struct page **pages; 140 omap_gem_get_pages(obj, &pages, false); 141 kunmap(pages[page_num]); 142 } 143 144 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer, 145 struct vm_area_struct *vma) 146 { 147 struct drm_gem_object *obj = buffer->priv; 148 int ret = 0; 149 150 ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma); 151 if (ret < 0) 152 return ret; 153 154 return omap_gem_mmap_obj(obj, vma); 155 } 156 157 static struct dma_buf_ops omap_dmabuf_ops = { 158 .map_dma_buf = omap_gem_map_dma_buf, 159 .unmap_dma_buf = omap_gem_unmap_dma_buf, 160 .release = omap_gem_dmabuf_release, 161 .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access, 162 .end_cpu_access = omap_gem_dmabuf_end_cpu_access, 163 .map_atomic = omap_gem_dmabuf_kmap_atomic, 164 .unmap_atomic = omap_gem_dmabuf_kunmap_atomic, 165 .map = omap_gem_dmabuf_kmap, 166 .unmap = omap_gem_dmabuf_kunmap, 167 .mmap = omap_gem_dmabuf_mmap, 168 }; 169 170 struct dma_buf *omap_gem_prime_export(struct drm_device *dev, 171 struct drm_gem_object *obj, int flags) 172 { 173 DEFINE_DMA_BUF_EXPORT_INFO(exp_info); 174 175 exp_info.ops = &omap_dmabuf_ops; 176 exp_info.size = obj->size; 177 exp_info.flags = flags; 178 exp_info.priv = obj; 179 180 return dma_buf_export(&exp_info); 181 } 182 183 /* ----------------------------------------------------------------------------- 184 * DMABUF Import 185 */ 186 187 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, 188 struct dma_buf *dma_buf) 189 { 190 struct dma_buf_attachment *attach; 191 struct drm_gem_object *obj; 192 struct sg_table *sgt; 193 int ret; 194 195 if (dma_buf->ops == &omap_dmabuf_ops) { 196 obj = dma_buf->priv; 197 if (obj->dev == dev) { 198 /* 199 * Importing dmabuf exported from out own gem increases 200 * refcount on gem itself instead of f_count of dmabuf. 201 */ 202 drm_gem_object_reference(obj); 203 return obj; 204 } 205 } 206 207 attach = dma_buf_attach(dma_buf, dev->dev); 208 if (IS_ERR(attach)) 209 return ERR_CAST(attach); 210 211 get_dma_buf(dma_buf); 212 213 sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL); 214 if (IS_ERR(sgt)) { 215 ret = PTR_ERR(sgt); 216 goto fail_detach; 217 } 218 219 obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt); 220 if (IS_ERR(obj)) { 221 ret = PTR_ERR(obj); 222 goto fail_unmap; 223 } 224 225 obj->import_attach = attach; 226 227 return obj; 228 229 fail_unmap: 230 dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL); 231 fail_detach: 232 dma_buf_detach(dma_buf, attach); 233 dma_buf_put(dma_buf); 234 235 return ERR_PTR(ret); 236 } 237