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-rw-r--r--drivers/gpu/drm/Makefile2
-rw-r--r--drivers/gpu/drm/drm_buffer.c184
-rw-r--r--include/drm/drm_buffer.h148
3 files changed, 333 insertions, 1 deletions
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 39c5aa75b8f1..abe3f446ca48 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -4,7 +4,7 @@
4 4
5ccflags-y := -Iinclude/drm 5ccflags-y := -Iinclude/drm
6 6
7drm-y := drm_auth.o drm_bufs.o drm_cache.o \ 7drm-y := drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \
8 drm_context.o drm_dma.o drm_drawable.o \ 8 drm_context.o drm_dma.o drm_drawable.o \
9 drm_drv.o drm_fops.o drm_gem.o drm_ioctl.o drm_irq.o \ 9 drm_drv.o drm_fops.o drm_gem.o drm_ioctl.o drm_irq.o \
10 drm_lock.o drm_memory.o drm_proc.o drm_stub.o drm_vm.o \ 10 drm_lock.o drm_memory.o drm_proc.o drm_stub.o drm_vm.o \
diff --git a/drivers/gpu/drm/drm_buffer.c b/drivers/gpu/drm/drm_buffer.c
new file mode 100644
index 000000000000..55d03ed05000
--- /dev/null
+++ b/drivers/gpu/drm/drm_buffer.c
@@ -0,0 +1,184 @@
1/**************************************************************************
2 *
3 * Copyright 2010 Pauli Nieminen.
4 * All Rights Reserved.
5 *
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:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
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.
25 *
26 *
27 **************************************************************************/
28/*
29 * Multipart buffer for coping data which is larger than the page size.
30 *
31 * Authors:
32 * Pauli Nieminen <suokkos-at-gmail-dot-com>
33 */
34
35#include "drm_buffer.h"
36
37/**
38 * Allocate the drm buffer object.
39 *
40 * buf: Pointer to a pointer where the object is stored.
41 * size: The number of bytes to allocate.
42 */
43int drm_buffer_alloc(struct drm_buffer **buf, int size)
44{
45 int nr_pages = size / PAGE_SIZE + 1;
46 int idx;
47
48 /* Allocating pointer table to end of structure makes drm_buffer
49 * variable sized */
50 *buf = kzalloc(sizeof(struct drm_buffer) + nr_pages*sizeof(char *),
51 GFP_KERNEL);
52
53 if (*buf == NULL) {
54 DRM_ERROR("Failed to allocate drm buffer object to hold"
55 " %d bytes in %d pages.\n",
56 size, nr_pages);
57 return -ENOMEM;
58 }
59
60 (*buf)->size = size;
61
62 for (idx = 0; idx < nr_pages; ++idx) {
63
64 (*buf)->data[idx] =
65 kmalloc(min(PAGE_SIZE, size - idx * PAGE_SIZE),
66 GFP_KERNEL);
67
68
69 if ((*buf)->data[idx] == NULL) {
70 DRM_ERROR("Failed to allocate %dth page for drm"
71 " buffer with %d bytes and %d pages.\n",
72 idx + 1, size, nr_pages);
73 goto error_out;
74 }
75
76 }
77
78 return 0;
79
80error_out:
81
82 /* Only last element can be null pointer so check for it first. */
83 if ((*buf)->data[idx])
84 kfree((*buf)->data[idx]);
85
86 for (--idx; idx >= 0; --idx)
87 kfree((*buf)->data[idx]);
88
89 kfree(*buf);
90 return -ENOMEM;
91}
92EXPORT_SYMBOL(drm_buffer_alloc);
93
94/**
95 * Copy the user data to the begin of the buffer and reset the processing
96 * iterator.
97 *
98 * user_data: A pointer the data that is copied to the buffer.
99 * size: The Number of bytes to copy.
100 */
101extern int drm_buffer_copy_from_user(struct drm_buffer *buf,
102 void __user *user_data, int size)
103{
104 int nr_pages = size / PAGE_SIZE + 1;
105 int idx;
106
107 if (size > buf->size) {
108 DRM_ERROR("Requesting to copy %d bytes to a drm buffer with"
109 " %d bytes space\n",
110 size, buf->size);
111 return -EFAULT;
112 }
113
114 for (idx = 0; idx < nr_pages; ++idx) {
115
116 if (DRM_COPY_FROM_USER(buf->data[idx],
117 user_data + idx * PAGE_SIZE,
118 min(PAGE_SIZE, size - idx * PAGE_SIZE))) {
119 DRM_ERROR("Failed to copy user data (%p) to drm buffer"
120 " (%p) %dth page.\n",
121 user_data, buf, idx);
122 return -EFAULT;
123
124 }
125 }
126 buf->iterator = 0;
127 return 0;
128}
129EXPORT_SYMBOL(drm_buffer_copy_from_user);
130
131/**
132 * Free the drm buffer object
133 */
134void drm_buffer_free(struct drm_buffer *buf)
135{
136
137 if (buf != NULL) {
138
139 int nr_pages = buf->size / PAGE_SIZE + 1;
140 int idx;
141 for (idx = 0; idx < nr_pages; ++idx)
142 kfree(buf->data[idx]);
143
144 kfree(buf);
145 }
146}
147EXPORT_SYMBOL(drm_buffer_free);
148
149/**
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
153 * by caller.
154 *
155 * The processing location of the buffer is also advanced to the next byte
156 * after the object.
157 *
158 * objsize: The size of the objet in bytes.
159 * stack_obj: A pointer to a memory location where object can be copied.
160 */
161void *drm_buffer_read_object(struct drm_buffer *buf,
162 int objsize, void *stack_obj)
163{
164 int idx = drm_buffer_index(buf);
165 int page = drm_buffer_page(buf);
166 void *obj = 0;
167
168 if (idx + objsize <= PAGE_SIZE) {
169 obj = &buf->data[page][idx];
170 } else {
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);
174
175 memcpy(stack_obj + beginsz, &buf->data[page + 1][0],
176 objsize - beginsz);
177
178 obj = stack_obj;
179 }
180
181 drm_buffer_advance(buf, objsize);
182 return obj;
183}
184EXPORT_SYMBOL(drm_buffer_read_object);
diff --git a/include/drm/drm_buffer.h b/include/drm/drm_buffer.h
new file mode 100644
index 000000000000..322dbff3f861
--- /dev/null
+++ b/include/drm/drm_buffer.h
@@ -0,0 +1,148 @@
1/**************************************************************************
2 *
3 * Copyright 2010 Pauli Nieminen.
4 * All Rights Reserved.
5 *
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:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
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.
25 *
26 *
27 **************************************************************************/
28/*
29 * Multipart buffer for coping data which is larger than the page size.
30 *
31 * Authors:
32 * Pauli Nieminen <suokkos-at-gmail-dot-com>
33 */
34
35#ifndef _DRM_BUFFER_H_
36#define _DRM_BUFFER_H_
37
38#include "drmP.h"
39
40struct drm_buffer {
41 int iterator;
42 int size;
43 char *data[];
44};
45
46
47/**
48 * Return the index of page that buffer is currently pointing at.
49 */
50static inline int drm_buffer_page(struct drm_buffer *buf)
51{
52 return buf->iterator / PAGE_SIZE;
53}
54/**
55 * Return the index of the current byte in the page
56 */
57static inline int drm_buffer_index(struct drm_buffer *buf)
58{
59 return buf->iterator & (PAGE_SIZE - 1);
60}
61/**
62 * Return number of bytes that is left to process
63 */
64static inline int drm_buffer_unprocessed(struct drm_buffer *buf)
65{
66 return buf->size - buf->iterator;
67}
68
69/**
70 * Advance the buffer iterator number of bytes that is given.
71 */
72static inline void drm_buffer_advance(struct drm_buffer *buf, int bytes)
73{
74 buf->iterator += bytes;
75}
76
77/**
78 * Allocate the drm buffer object.
79 *
80 * buf: A pointer to a pointer where the object is stored.
81 * size: The number of bytes to allocate.
82 */
83extern int drm_buffer_alloc(struct drm_buffer **buf, int size);
84
85/**
86 * Copy the user data to the begin of the buffer and reset the processing
87 * iterator.
88 *
89 * user_data: A pointer the data that is copied to the buffer.
90 * size: The Number of bytes to copy.
91 */
92extern int drm_buffer_copy_from_user(struct drm_buffer *buf,
93 void __user *user_data, int size);
94
95/**
96 * Free the drm buffer object
97 */
98extern void drm_buffer_free(struct drm_buffer *buf);
99
100/**
101 * Read an object from buffer that may be split to multiple parts. If object
102 * is not split function just returns the pointer to object in buffer. But in
103 * case of split object data is copied to given stack object that is suplied
104 * by caller.
105 *
106 * The processing location of the buffer is also advanced to the next byte
107 * after the object.
108 *
109 * objsize: The size of the objet in bytes.
110 * stack_obj: A pointer to a memory location where object can be copied.
111 */
112extern void *drm_buffer_read_object(struct drm_buffer *buf,
113 int objsize, void *stack_obj);
114
115/**
116 * Returns the pointer to the dword which is offset number of elements from the
117 * current processing location.
118 *
119 * Caller must make sure that dword is not split in the buffer. This
120 * requirement is easily met if all the sizes of objects in buffer are
121 * multiples of dword and PAGE_SIZE is multiple dword.
122 *
123 * Call to this function doesn't change the processing location.
124 *
125 * offset: The index of the dword relative to the internat iterator.
126 */
127static inline void *drm_buffer_pointer_to_dword(struct drm_buffer *buffer,
128 int offset)
129{
130 int iter = buffer->iterator + offset * 4;
131 return &buffer->data[iter / PAGE_SIZE][iter & (PAGE_SIZE - 1)];
132}
133/**
134 * Returns the pointer to the dword which is offset number of elements from
135 * the current processing location.
136 *
137 * Call to this function doesn't change the processing location.
138 *
139 * offset: The index of the byte relative to the internat iterator.
140 */
141static inline void *drm_buffer_pointer_to_byte(struct drm_buffer *buffer,
142 int offset)
143{
144 int iter = buffer->iterator + offset;
145 return &buffer->data[iter / PAGE_SIZE][iter & (PAGE_SIZE - 1)];
146}
147
148#endif
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