omap_gem_dmabuf.c 4.0 KB

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