1 /**************************************************************************
3 * Copyright 2010 Pauli Nieminen.
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
27 **************************************************************************/
29 * Multipart buffer for coping data which is larger than the page size.
32 * Pauli Nieminen <suokkos-at-gmail-dot-com>
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
38 #include <dev/drm2/drm_buffer.h>
41 * Allocate the drm buffer object.
43 * buf: Pointer to a pointer where the object is stored.
44 * size: The number of bytes to allocate.
46 int drm_buffer_alloc(struct drm_buffer **buf, int size)
48 int nr_pages = size / PAGE_SIZE + 1;
51 /* Allocating pointer table to end of structure makes drm_buffer
53 *buf = malloc(sizeof(struct drm_buffer) + nr_pages*sizeof(char *),
54 DRM_MEM_DRIVER, M_ZERO | M_WAITOK);
57 DRM_ERROR("Failed to allocate drm buffer object to hold"
58 " %d bytes in %d pages.\n",
65 for (idx = 0; idx < nr_pages; ++idx) {
68 malloc(min(PAGE_SIZE, size - idx * PAGE_SIZE),
69 DRM_MEM_DRIVER, M_WAITOK);
72 if ((*buf)->data[idx] == NULL) {
73 DRM_ERROR("Failed to allocate %dth page for drm"
74 " buffer with %d bytes and %d pages.\n",
75 idx + 1, size, nr_pages);
85 /* Only last element can be null pointer so check for it first. */
86 if ((*buf)->data[idx])
87 free((*buf)->data[idx], DRM_MEM_DRIVER);
89 for (--idx; idx >= 0; --idx)
90 free((*buf)->data[idx], DRM_MEM_DRIVER);
92 free(*buf, DRM_MEM_DRIVER);
97 * Copy the user data to the begin of the buffer and reset the processing
100 * user_data: A pointer the data that is copied to the buffer.
101 * size: The Number of bytes to copy.
103 int drm_buffer_copy_from_user(struct drm_buffer *buf,
104 void __user *user_data, int size)
106 int nr_pages = size / PAGE_SIZE + 1;
109 if (size > buf->size) {
110 DRM_ERROR("Requesting to copy %d bytes to a drm buffer with"
116 for (idx = 0; idx < nr_pages; ++idx) {
118 if (DRM_COPY_FROM_USER(buf->data[idx],
119 (char *)user_data + idx * PAGE_SIZE,
120 min(PAGE_SIZE, size - idx * PAGE_SIZE))) {
121 DRM_ERROR("Failed to copy user data (%p) to drm buffer"
122 " (%p) %dth page.\n",
123 user_data, buf, idx);
133 * Free the drm buffer object
135 void drm_buffer_free(struct drm_buffer *buf)
140 int nr_pages = buf->size / PAGE_SIZE + 1;
142 for (idx = 0; idx < nr_pages; ++idx)
143 free(buf->data[idx], DRM_MEM_DRIVER);
145 free(buf, DRM_MEM_DRIVER);
150 * Read an object from buffer that may be split to multiple parts. If object
151 * is not split function just returns the pointer to object in buffer. But in
152 * case of split object data is copied to given stack object that is suplied
155 * The processing location of the buffer is also advanced to the next byte
158 * objsize: The size of the objet in bytes.
159 * stack_obj: A pointer to a memory location where object can be copied.
161 void *drm_buffer_read_object(struct drm_buffer *buf,
162 int objsize, void *stack_obj)
164 int idx = drm_buffer_index(buf);
165 int page = drm_buffer_page(buf);
168 if (idx + objsize <= PAGE_SIZE) {
169 obj = &buf->data[page][idx];
171 /* The object is split which forces copy to temporary object.*/
172 int beginsz = PAGE_SIZE - idx;
173 memcpy(stack_obj, &buf->data[page][idx], beginsz);
175 memcpy((char *)stack_obj + beginsz, &buf->data[page + 1][0],
181 drm_buffer_advance(buf, objsize);