de_common.c 3.7 KB

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  1. /*
  2. * de_common.h
  3. */
  4. #include <linux/dma-buf.h>
  5. #include <linux/err.h>
  6. #include <linux/types.h>
  7. #include <linux/module.h>
  8. #include <linux/slab.h>
  9. #include <linux/uaccess.h>
  10. #include <linux/version.h>
  11. #include <linux/miscdevice.h>
  12. #include "uapi/dmabuf_exporter.h"
  13. #include "de_heap.h"
  14. /*
  15. * Because this file is used in all modules, the kernel build system does
  16. * not define KBUILD_MODNAME. This causes a build failure in kernels where
  17. * dynamic debug is enabled, in all instances of pr_debug().
  18. *
  19. * dynamic debug messages for this file will use this name
  20. */
  21. #ifndef KBUILD_MODNAME
  22. #define KBUILD_MODNAME "dmabuf_exporter"
  23. #endif
  24. static struct miscdevice dmabuf_miscdevice;
  25. static int de_file_open(struct inode *inode, struct file *file)
  26. {
  27. pr_debug("%s\n", __func__);
  28. file->private_data = NULL;
  29. return 0;
  30. }
  31. static int dmabuf_ioctl_create(struct file *file, unsigned long arg_size)
  32. {
  33. void *private_data;
  34. size_t size;
  35. int ret;
  36. pr_debug("%s: private_data %p\n", __func__, file->private_data);
  37. size = (arg_size + PAGE_SIZE - 1) & (~(PAGE_SIZE - 1));
  38. pr_debug("%s: requested size %lu PAGE_SIZE %lu actual size %zu\n",
  39. __func__, arg_size, PAGE_SIZE, size);
  40. if (file->private_data) {
  41. pr_err("%s: buffer already created!\n", __func__);
  42. return -EBUSY;
  43. }
  44. ret = de_heap_buffer_create(size, PAGE_SIZE, &private_data);
  45. if (ret)
  46. return ret;
  47. file->private_data = private_data;
  48. return 0;
  49. }
  50. static int dmabuf_ioctl_export(struct file *file, unsigned long flags)
  51. {
  52. pr_debug("%s: private_data %p\n", __func__, file->private_data);
  53. if (file->private_data)
  54. return de_heap_export_fd(file->private_data, flags);
  55. pr_err("%s: buffer has not been created!\n", __func__);
  56. return -ENODEV;
  57. }
  58. static int de_file_release(struct inode *inode, struct file *file)
  59. {
  60. pr_debug("%s: private_data %p\n", __func__, file->private_data);
  61. if (file->private_data) {
  62. de_heap_buffer_free(file->private_data);
  63. file->private_data = NULL;
  64. }
  65. return 0;
  66. }
  67. static long de_file_ioctl(struct file *file, unsigned int cmd,
  68. unsigned long arg)
  69. {
  70. pr_debug("%s: cmd %x arg %lx\n", __func__, cmd, arg);
  71. switch (cmd) {
  72. case DMABUF_IOCTL_CREATE:
  73. #ifdef CONFIG_COMPAT
  74. case COMPAT_DMABUF_IOCTL_CREATE:
  75. #endif
  76. return dmabuf_ioctl_create(file, arg);
  77. case DMABUF_IOCTL_EXPORT:
  78. #ifdef CONFIG_COMPAT
  79. case COMPAT_DMABUF_IOCTL_EXPORT:
  80. #endif
  81. return dmabuf_ioctl_export(file, arg);
  82. default:
  83. pr_err("%s: unknown cmd %x\n", __func__, cmd);
  84. return -ENOTTY;
  85. }
  86. }
  87. static const struct file_operations dmabuf_fops = {
  88. .owner = THIS_MODULE,
  89. .open = de_file_open,
  90. .release = de_file_release,
  91. .unlocked_ioctl = de_file_ioctl,
  92. #ifdef CONFIG_COMPAT
  93. .compat_ioctl = de_file_ioctl,
  94. #endif
  95. };
  96. static int __init dmabuf_device_init(void)
  97. {
  98. int ret;
  99. pr_info("%s\n", __func__);
  100. dmabuf_miscdevice.minor = 128;
  101. dmabuf_miscdevice.name = "dmabuf";
  102. dmabuf_miscdevice.fops = &dmabuf_fops;
  103. dmabuf_miscdevice.parent = NULL;
  104. dmabuf_miscdevice.mode = 0666;
  105. ret = misc_register(&dmabuf_miscdevice);
  106. if (ret < 0) {
  107. pr_err("%s: failed to register misc device %s\n",
  108. __func__, dmabuf_miscdevice.name);
  109. return ret;
  110. }
  111. pr_info("%s: registered misc device %s\n",
  112. __func__, dmabuf_miscdevice.name);
  113. ret = de_heap_heap_init();
  114. if (ret < 0) {
  115. misc_deregister(&dmabuf_miscdevice);
  116. return ret;
  117. }
  118. return 0;
  119. }
  120. static void __exit dmabuf_device_deinit(void)
  121. {
  122. pr_info("%s\n", __func__);
  123. de_heap_heap_deinit();
  124. misc_deregister(&dmabuf_miscdevice);
  125. }
  126. module_init(dmabuf_device_init);
  127. module_exit(dmabuf_device_deinit);
  128. MODULE_AUTHOR("GPL");
  129. MODULE_DESCRIPTION("DMA-BUF test driver");
  130. MODULE_LICENSE("GPL v2");
  131. /*
  132. * coding style for emacs
  133. *
  134. * Local variables:
  135. * indent-tabs-mode: t
  136. * tab-width: 8
  137. * c-basic-offset: 8
  138. * End:
  139. */