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1 /*
2  * Copyright (c) 2014-2015, Linaro Ltd and Contributors. All rights reserved.
3  * Copyright (c) 2014-2015, Hisilicon Ltd and Contributors. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * Redistributions of source code must retain the above copyright notice, this
9  * list of conditions and the following disclaimer.
10  *
11  * Redistributions in binary form must reproduce the above copyright notice,
12  * this list of conditions and the following disclaimer in the documentation
13  * and/or other materials provided with the distribution.
14  *
15  * Neither the name of ARM nor the names of its contributors may be used
16  * to endorse or promote products derived from this software without specific
17  * prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
23  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <assert.h>
33 #include <bl_common.h>
34 #include <debug.h>
35 #include <errno.h>
36 #include <io_block.h>
37 #include <io_driver.h>
38 #include <io_storage.h>
39 #include <mmio.h>
40 #include <stdint.h>
41 #include <string.h>
42 
43 /* As we need to be able to keep state for seek, only one file can be open
44  * at a time. Make this a structure and point to the entity->info. When we
45  * can malloc memory we can change this to support more open files.
46  */
47 typedef struct {
48 	/* Use the 'in_use' flag as any value for base and file_pos could be
49 	 * valid.
50 	 */
51 	int		in_use;
52 	uintptr_t	base;
53 	size_t		file_pos;
54 	uint32_t	flags;
55 } file_state_t;
56 
57 struct block_info {
58 	struct block_ops	ops;
59 	int			init;
60 	uint32_t		flags;
61 };
62 
63 static file_state_t current_file = {0};
64 
65 static struct block_info block_info;
66 
67 static int block_open(io_dev_info_t *dev_info, const uintptr_t spec,
68 		      io_entity_t *entity);
69 static int block_seek(io_entity_t *entity, int mode, ssize_t offset);
70 static int block_read(io_entity_t *entity, uintptr_t buffer,
71 		      size_t length, size_t *length_read);
72 static int block_write(io_entity_t *entity, uintptr_t buffer,
73 		       size_t length, size_t *length_written);
74 static int block_close(io_entity_t *entity);
75 
76 static int blk_dev_init(io_dev_info_t *dev_info,
77 			const uintptr_t init_params);
78 static int blk_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info);
79 static int blk_dev_close(io_dev_info_t *dev_info);
80 
81 /* Identify the device type as block */
device_type_block(void)82 io_type_t device_type_block(void)
83 {
84 	return IO_TYPE_BLOCK;
85 }
86 
87 static const io_dev_connector_t blk_dev_connector = {
88 	.dev_open = blk_dev_open
89 };
90 
91 static const io_dev_funcs_t blk_dev_funcs = {
92 	.type = device_type_block,
93 	.open = block_open,
94 	.seek = block_seek,
95 	.size = NULL,
96 	.read = block_read,
97 	.write = block_write,
98 	.close = block_close,
99 	.dev_init = blk_dev_init,
100 	.dev_close = blk_dev_close,
101 };
102 
103 
104 /* No state associated with this device so structure can be const */
105 static const io_dev_info_t blk_dev_info = {
106 	.funcs = &blk_dev_funcs,
107 	.info = (uintptr_t)&block_info,
108 };
109 
110 /* Open a connection to the block device */
blk_dev_open(const uintptr_t dev_spec,io_dev_info_t ** dev_info)111 static int blk_dev_open(const uintptr_t dev_spec __attribute__((unused)),
112 			   io_dev_info_t **dev_info)
113 {
114 	struct block_ops	*funcs, *block_spec;
115 
116 	assert(dev_info != NULL);
117 	*dev_info = (io_dev_info_t *)&blk_dev_info; /* cast away const */
118 
119 	if (dev_spec) {
120 		funcs = &block_info.ops;
121 		block_spec = (struct block_ops *)dev_spec;
122 		funcs->init = block_spec->init;
123 		funcs->read = block_spec->read;
124 		funcs->write = block_spec->write;
125 	}
126 
127 	return IO_SUCCESS;
128 }
129 
130 /* Close a connection to the block device */
blk_dev_close(io_dev_info_t * dev_info)131 static int blk_dev_close(io_dev_info_t *dev_info)
132 {
133 	/* NOP */
134 	/* TODO: Consider tracking open files and cleaning them up here */
135 	return IO_SUCCESS;
136 }
137 
138 
139 /* Open a file on the block device */
140 /* TODO: Can we do any sensible limit checks on requested memory */
block_open(io_dev_info_t * dev_info,const uintptr_t spec,io_entity_t * entity)141 static int block_open(io_dev_info_t *dev_info, const uintptr_t spec,
142 			     io_entity_t *entity)
143 {
144 	int result = IO_FAIL;
145 	const io_block_spec_t *block_spec = (io_block_spec_t *)spec;
146 	struct block_info *info = (struct block_info *)(dev_info->info);
147 
148 	/* Since we need to track open state for seek() we only allow one open
149 	 * spec at a time. When we have dynamic memory we can malloc and set
150 	 * entity->info.
151 	 */
152 	if (current_file.in_use == 0) {
153 		assert(block_spec != NULL);
154 		assert(entity != NULL);
155 
156 		current_file.in_use = 1;
157 		current_file.base = block_spec->offset;
158 		/* File cursor offset for seek and incremental reads etc. */
159 		current_file.file_pos = 0;
160 		current_file.flags = info->flags;
161 		entity->info = (uintptr_t)&current_file;
162 		result = IO_SUCCESS;
163 	} else {
164 		WARN("A block device is already active. Close first.\n");
165 		result = IO_RESOURCES_EXHAUSTED;
166 	}
167 
168 	return result;
169 }
170 
171 /* Seek to a particular file offset on the block device */
block_seek(io_entity_t * entity,int mode,ssize_t offset)172 static int block_seek(io_entity_t *entity, int mode, ssize_t offset)
173 {
174 	int result = IO_FAIL;
175 
176 	/* We only support IO_SEEK_SET for the moment. */
177 	if (mode == IO_SEEK_SET) {
178 		assert(entity != NULL);
179 
180 		/* TODO: can we do some basic limit checks on seek? */
181 		((file_state_t *)entity->info)->file_pos = offset;
182 		result = IO_SUCCESS;
183 	} else {
184 		result = IO_FAIL;
185 	}
186 
187 	return result;
188 }
189 
190 
191 /* Read data from a file on the block device */
block_read(io_entity_t * entity,uintptr_t buffer,size_t length,size_t * length_read)192 static int block_read(io_entity_t *entity, uintptr_t buffer,
193 		      size_t length, size_t *length_read)
194 {
195 	file_state_t *fp;
196 	int result;
197 
198 	assert(entity != NULL);
199 	assert(buffer != (uintptr_t)NULL);
200 	assert(length_read != NULL);
201 
202 	fp = (file_state_t *)entity->info;
203 
204 	if (!block_info.ops.read) {
205 		ERROR("There's no read function on the block device.\n");
206 		return IO_NOT_SUPPORTED;
207 	}
208 	result = block_info.ops.read(fp->base + fp->file_pos, length,
209 				     buffer, fp->flags);
210 	if (result) {
211 		WARN("Failed to read block offset 0x%x\n",
212 		     fp->base + fp->file_pos);
213 		return result;
214 	}
215 
216 	*length_read = length;
217 	/* advance the file 'cursor' for incremental reads */
218 	fp->file_pos += length;
219 
220 	return IO_SUCCESS;
221 }
222 
block_write(io_entity_t * entity,uintptr_t buffer,size_t length,size_t * length_written)223 static int block_write(io_entity_t *entity, uintptr_t buffer,
224 		       size_t length, size_t *length_written)
225 {
226 	file_state_t *fp;
227 	int result;
228 
229 	assert(entity != NULL);
230 	assert(buffer != (uintptr_t)NULL);
231 	assert(length_written != NULL);
232 
233 	fp = (file_state_t *)entity->info;
234 
235 	if (!block_info.ops.write) {
236 		ERROR("There's no write function on the block device.\n");
237 		return IO_NOT_SUPPORTED;
238 	}
239 	result = block_info.ops.write(fp->base + fp->file_pos, length,
240 				      buffer, fp->flags);
241 	if (result) {
242 		WARN("Failed to write block offset 0x%x\n",
243 		     fp->base + fp->file_pos);
244 		return result;
245 	}
246 
247 	*length_written = length;
248 	/* advance the file 'cursor' for incremental reads */
249 	fp->file_pos += length;
250 
251 	return IO_SUCCESS;
252 }
253 
254 /* Close a file on the BLOCK device */
block_close(io_entity_t * entity)255 static int block_close(io_entity_t *entity)
256 {
257 	assert(entity != NULL);
258 
259 	entity->info = 0;
260 
261 	/* This would be a mem free() if we had malloc.*/
262 	memset((void *)&current_file, 0, sizeof(current_file));
263 
264 	return IO_SUCCESS;
265 }
266 
blk_dev_init(io_dev_info_t * dev_info,const uintptr_t init_params)267 static int blk_dev_init(io_dev_info_t *dev_info, const uintptr_t init_params)
268 {
269 	struct block_info *info = (struct block_info *)(dev_info->info);
270 
271 	if (!info->init) {
272 		if (block_info.ops.init)
273 			block_info.ops.init();
274 		info->init = 1;
275 	}
276 	info->flags = init_params;
277 	return IO_SUCCESS;
278 }
279 
280 /* Exported functions */
281 
282 /* Register the block driver with the IO abstraction */
register_io_dev_block(const io_dev_connector_t ** dev_con)283 int register_io_dev_block(const io_dev_connector_t **dev_con)
284 {
285 	int result = IO_FAIL;
286 	assert(dev_con != NULL);
287 
288 	result = io_register_device(&blk_dev_info);
289 	if (result == IO_SUCCESS)
290 		*dev_con = &blk_dev_connector;
291 
292 	return result;
293 }
294