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 paddr; 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_get_paddr(obj, &paddr, true); 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(paddr)), obj->size, 0); 55 sg_dma_address(sg->sgl) = paddr; 56 57 /* this should be after _get_paddr() to ensure we have pages attached */ 58 omap_gem_dma_sync(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_put_paddr(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 size_t start, size_t len, 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 void omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer, 101 size_t start, size_t len, enum dma_data_direction dir) 102 { 103 struct drm_gem_object *obj = buffer->priv; 104 omap_gem_put_pages(obj); 105 } 106 107 108 static void *omap_gem_dmabuf_kmap_atomic(struct dma_buf *buffer, 109 unsigned long page_num) 110 { 111 struct drm_gem_object *obj = buffer->priv; 112 struct page **pages; 113 omap_gem_get_pages(obj, &pages, false); 114 omap_gem_cpu_sync(obj, page_num); 115 return kmap_atomic(pages[page_num]); 116 } 117 118 static void omap_gem_dmabuf_kunmap_atomic(struct dma_buf *buffer, 119 unsigned long page_num, void *addr) 120 { 121 kunmap_atomic(addr); 122 } 123 124 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer, 125 unsigned long page_num) 126 { 127 struct drm_gem_object *obj = buffer->priv; 128 struct page **pages; 129 omap_gem_get_pages(obj, &pages, false); 130 omap_gem_cpu_sync(obj, page_num); 131 return kmap(pages[page_num]); 132 } 133 134 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer, 135 unsigned long page_num, void *addr) 136 { 137 struct drm_gem_object *obj = buffer->priv; 138 struct page **pages; 139 omap_gem_get_pages(obj, &pages, false); 140 kunmap(pages[page_num]); 141 } 142 143 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer, 144 struct vm_area_struct *vma) 145 { 146 struct drm_gem_object *obj = buffer->priv; 147 int ret = 0; 148 149 if (WARN_ON(!obj->filp)) 150 return -EINVAL; 151 152 ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma); 153 if (ret < 0) 154 return ret; 155 156 return omap_gem_mmap_obj(obj, vma); 157 } 158 159 static struct dma_buf_ops omap_dmabuf_ops = { 160 .map_dma_buf = omap_gem_map_dma_buf, 161 .unmap_dma_buf = omap_gem_unmap_dma_buf, 162 .release = omap_gem_dmabuf_release, 163 .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access, 164 .end_cpu_access = omap_gem_dmabuf_end_cpu_access, 165 .kmap_atomic = omap_gem_dmabuf_kmap_atomic, 166 .kunmap_atomic = omap_gem_dmabuf_kunmap_atomic, 167 .kmap = omap_gem_dmabuf_kmap, 168 .kunmap = omap_gem_dmabuf_kunmap, 169 .mmap = omap_gem_dmabuf_mmap, 170 }; 171 172 struct dma_buf *omap_gem_prime_export(struct drm_device *dev, 173 struct drm_gem_object *obj, int flags) 174 { 175 DEFINE_DMA_BUF_EXPORT_INFO(exp_info); 176 177 exp_info.ops = &omap_dmabuf_ops; 178 exp_info.size = obj->size; 179 exp_info.flags = flags; 180 exp_info.priv = obj; 181 182 return dma_buf_export(&exp_info); 183 } 184 185 /* ----------------------------------------------------------------------------- 186 * DMABUF Import 187 */ 188 189 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, 190 struct dma_buf *dma_buf) 191 { 192 struct dma_buf_attachment *attach; 193 struct drm_gem_object *obj; 194 struct sg_table *sgt; 195 int ret; 196 197 if (dma_buf->ops == &omap_dmabuf_ops) { 198 obj = dma_buf->priv; 199 if (obj->dev == dev) { 200 /* 201 * Importing dmabuf exported from out own gem increases 202 * refcount on gem itself instead of f_count of dmabuf. 203 */ 204 drm_gem_object_reference(obj); 205 return obj; 206 } 207 } 208 209 attach = dma_buf_attach(dma_buf, dev->dev); 210 if (IS_ERR(attach)) 211 return ERR_CAST(attach); 212 213 get_dma_buf(dma_buf); 214 215 sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL); 216 if (IS_ERR(sgt)) { 217 ret = PTR_ERR(sgt); 218 goto fail_detach; 219 } 220 221 obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt); 222 if (IS_ERR(obj)) { 223 ret = PTR_ERR(obj); 224 goto fail_unmap; 225 } 226 227 obj->import_attach = attach; 228 229 return obj; 230 231 fail_unmap: 232 dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL); 233 fail_detach: 234 dma_buf_detach(dma_buf, attach); 235 dma_buf_put(dma_buf); 236 237 return ERR_PTR(ret); 238 } 239