xref: /openbmc/u-boot/lib/efi_loader/efi_disk.c (revision 9bfca9f9)
1 /*
2  *  EFI application disk support
3  *
4  *  Copyright (c) 2016 Alexander Graf
5  *
6  *  SPDX-License-Identifier:     GPL-2.0+
7  */
8 
9 #include <common.h>
10 #include <blk.h>
11 #include <dm.h>
12 #include <efi_loader.h>
13 #include <inttypes.h>
14 #include <part.h>
15 #include <malloc.h>
16 
17 static const efi_guid_t efi_block_io_guid = BLOCK_IO_GUID;
18 
19 struct efi_disk_obj {
20 	/* Generic EFI object parent class data */
21 	struct efi_object parent;
22 	/* EFI Interface callback struct for block I/O */
23 	struct efi_block_io ops;
24 	/* U-Boot ifname for block device */
25 	const char *ifname;
26 	/* U-Boot dev_index for block device */
27 	int dev_index;
28 	/* EFI Interface Media descriptor struct, referenced by ops */
29 	struct efi_block_io_media media;
30 	/* EFI device path to this block device */
31 	struct efi_device_path *dp;
32 	/* partition # */
33 	unsigned int part;
34 	/* handle to filesys proto (for partition objects) */
35 	struct efi_simple_file_system_protocol *volume;
36 	/* Offset into disk for simple partitions */
37 	lbaint_t offset;
38 	/* Internal block device */
39 	struct blk_desc *desc;
40 };
41 
42 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
43 			char extended_verification)
44 {
45 	EFI_ENTRY("%p, %x", this, extended_verification);
46 	return EFI_EXIT(EFI_DEVICE_ERROR);
47 }
48 
49 enum efi_disk_direction {
50 	EFI_DISK_READ,
51 	EFI_DISK_WRITE,
52 };
53 
54 static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
55 			u32 media_id, u64 lba, unsigned long buffer_size,
56 			void *buffer, enum efi_disk_direction direction)
57 {
58 	struct efi_disk_obj *diskobj;
59 	struct blk_desc *desc;
60 	int blksz;
61 	int blocks;
62 	unsigned long n;
63 
64 	diskobj = container_of(this, struct efi_disk_obj, ops);
65 	desc = (struct blk_desc *) diskobj->desc;
66 	blksz = desc->blksz;
67 	blocks = buffer_size / blksz;
68 	lba += diskobj->offset;
69 
70 	debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
71 	      __LINE__, blocks, lba, blksz, direction);
72 
73 	/* We only support full block access */
74 	if (buffer_size & (blksz - 1))
75 		return EFI_DEVICE_ERROR;
76 
77 	if (direction == EFI_DISK_READ)
78 		n = blk_dread(desc, lba, blocks, buffer);
79 	else
80 		n = blk_dwrite(desc, lba, blocks, buffer);
81 
82 	/* We don't do interrupts, so check for timers cooperatively */
83 	efi_timer_check();
84 
85 	debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
86 
87 	if (n != blocks)
88 		return EFI_DEVICE_ERROR;
89 
90 	return EFI_SUCCESS;
91 }
92 
93 static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
94 			u32 media_id, u64 lba, unsigned long buffer_size,
95 			void *buffer)
96 {
97 	void *real_buffer = buffer;
98 	efi_status_t r;
99 
100 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
101 	if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
102 		r = efi_disk_read_blocks(this, media_id, lba,
103 			EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
104 		if (r != EFI_SUCCESS)
105 			return r;
106 		return efi_disk_read_blocks(this, media_id, lba +
107 			EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
108 			buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
109 			buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
110 	}
111 
112 	real_buffer = efi_bounce_buffer;
113 #endif
114 
115 	EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
116 		  buffer_size, buffer);
117 
118 	r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
119 			       EFI_DISK_READ);
120 
121 	/* Copy from bounce buffer to real buffer if necessary */
122 	if ((r == EFI_SUCCESS) && (real_buffer != buffer))
123 		memcpy(buffer, real_buffer, buffer_size);
124 
125 	return EFI_EXIT(r);
126 }
127 
128 static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
129 			u32 media_id, u64 lba, unsigned long buffer_size,
130 			void *buffer)
131 {
132 	void *real_buffer = buffer;
133 	efi_status_t r;
134 
135 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
136 	if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
137 		r = efi_disk_write_blocks(this, media_id, lba,
138 			EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
139 		if (r != EFI_SUCCESS)
140 			return r;
141 		return efi_disk_write_blocks(this, media_id, lba +
142 			EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
143 			buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
144 			buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
145 	}
146 
147 	real_buffer = efi_bounce_buffer;
148 #endif
149 
150 	EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
151 		  buffer_size, buffer);
152 
153 	/* Populate bounce buffer if necessary */
154 	if (real_buffer != buffer)
155 		memcpy(real_buffer, buffer, buffer_size);
156 
157 	r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
158 			       EFI_DISK_WRITE);
159 
160 	return EFI_EXIT(r);
161 }
162 
163 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
164 {
165 	/* We always write synchronously */
166 	EFI_ENTRY("%p", this);
167 	return EFI_EXIT(EFI_SUCCESS);
168 }
169 
170 static const struct efi_block_io block_io_disk_template = {
171 	.reset = &efi_disk_reset,
172 	.read_blocks = &efi_disk_read_blocks,
173 	.write_blocks = &efi_disk_write_blocks,
174 	.flush_blocks = &efi_disk_flush_blocks,
175 };
176 
177 /*
178  * Get the simple file system protocol for a file device path.
179  *
180  * The full path provided is split into device part and into a file
181  * part. The device part is used to find the handle on which the
182  * simple file system protocol is installed.
183  *
184  * @full_path	device path including device and file
185  * @return	simple file system protocol
186  */
187 struct efi_simple_file_system_protocol *
188 efi_fs_from_path(struct efi_device_path *full_path)
189 {
190 	struct efi_object *efiobj;
191 	struct efi_handler *handler;
192 	struct efi_device_path *device_path;
193 	struct efi_device_path *file_path;
194 	efi_status_t ret;
195 
196 	/* Split the path into a device part and a file part */
197 	ret = efi_dp_split_file_path(full_path, &device_path, &file_path);
198 	if (ret != EFI_SUCCESS)
199 		return NULL;
200 	efi_free_pool(file_path);
201 
202 	/* Get the EFI object for the partition */
203 	efiobj = efi_dp_find_obj(device_path, NULL);
204 	efi_free_pool(device_path);
205 	if (!efiobj)
206 		return NULL;
207 
208 	/* Find the simple file system protocol */
209 	ret = efi_search_protocol(efiobj, &efi_simple_file_system_protocol_guid,
210 				  &handler);
211 	if (ret != EFI_SUCCESS)
212 		return NULL;
213 
214 	/* Return the simple file system protocol for the partition */
215 	return handler->protocol_interface;
216 }
217 
218 /*
219  * Create a device for a disk
220  *
221  * @name	not used
222  * @if_typename interface name for block device
223  * @desc	internal block device
224  * @dev_index   device index for block device
225  * @offset	offset into disk for simple partitions
226  */
227 static void efi_disk_add_dev(const char *name,
228 			     const char *if_typename,
229 			     struct blk_desc *desc,
230 			     int dev_index,
231 			     lbaint_t offset,
232 			     unsigned int part)
233 {
234 	struct efi_disk_obj *diskobj;
235 	efi_status_t ret;
236 
237 	/* Don't add empty devices */
238 	if (!desc->lba)
239 		return;
240 
241 	diskobj = calloc(1, sizeof(*diskobj));
242 	if (!diskobj)
243 		goto out_of_memory;
244 
245 	/* Hook up to the device list */
246 	efi_add_handle(&diskobj->parent);
247 
248 	/* Fill in object data */
249 	diskobj->dp = efi_dp_from_part(desc, part);
250 	diskobj->part = part;
251 	ret = efi_add_protocol(diskobj->parent.handle, &efi_block_io_guid,
252 			       &diskobj->ops);
253 	if (ret != EFI_SUCCESS)
254 		goto out_of_memory;
255 	ret = efi_add_protocol(diskobj->parent.handle, &efi_guid_device_path,
256 			       diskobj->dp);
257 	if (ret != EFI_SUCCESS)
258 		goto out_of_memory;
259 	if (part >= 1) {
260 		diskobj->volume = efi_simple_file_system(desc, part,
261 							 diskobj->dp);
262 		ret = efi_add_protocol(diskobj->parent.handle,
263 				       &efi_simple_file_system_protocol_guid,
264 				       diskobj->volume);
265 		if (ret != EFI_SUCCESS)
266 			goto out_of_memory;
267 	}
268 	diskobj->ops = block_io_disk_template;
269 	diskobj->ifname = if_typename;
270 	diskobj->dev_index = dev_index;
271 	diskobj->offset = offset;
272 	diskobj->desc = desc;
273 
274 	/* Fill in EFI IO Media info (for read/write callbacks) */
275 	diskobj->media.removable_media = desc->removable;
276 	diskobj->media.media_present = 1;
277 	diskobj->media.block_size = desc->blksz;
278 	diskobj->media.io_align = desc->blksz;
279 	diskobj->media.last_block = desc->lba - offset;
280 	if (part != 0)
281 		diskobj->media.logical_partition = 1;
282 	diskobj->ops.media = &diskobj->media;
283 	return;
284 out_of_memory:
285 	printf("ERROR: Out of memory\n");
286 }
287 
288 static int efi_disk_create_partitions(struct blk_desc *desc,
289 				      const char *if_typename,
290 				      int diskid,
291 				      const char *pdevname)
292 {
293 	int disks = 0;
294 	char devname[32] = { 0 }; /* dp->str is u16[32] long */
295 	disk_partition_t info;
296 	int part;
297 
298 	/* Add devices for each partition */
299 	for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
300 		if (part_get_info(desc, part, &info))
301 			continue;
302 		snprintf(devname, sizeof(devname), "%s:%d", pdevname,
303 			 part);
304 		efi_disk_add_dev(devname, if_typename, desc, diskid,
305 				 info.start, part);
306 		disks++;
307 	}
308 
309 	return disks;
310 }
311 
312 /*
313  * U-Boot doesn't have a list of all online disk devices. So when running our
314  * EFI payload, we scan through all of the potentially available ones and
315  * store them in our object pool.
316  *
317  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
318  * Consider converting the code to look up devices as needed. The EFI device
319  * could be a child of the UCLASS_BLK block device, perhaps.
320  *
321  * This gets called from do_bootefi_exec().
322  */
323 int efi_disk_register(void)
324 {
325 	int disks = 0;
326 #ifdef CONFIG_BLK
327 	struct udevice *dev;
328 
329 	for (uclass_first_device_check(UCLASS_BLK, &dev);
330 	     dev;
331 	     uclass_next_device_check(&dev)) {
332 		struct blk_desc *desc = dev_get_uclass_platdata(dev);
333 		const char *if_typename = blk_get_if_type_name(desc->if_type);
334 
335 		printf("Scanning disk %s...\n", dev->name);
336 
337 		/* Add block device for the full device */
338 		efi_disk_add_dev(dev->name, if_typename, desc,
339 				 desc->devnum, 0, 0);
340 
341 		disks++;
342 
343 		/* Partitions show up as block devices in EFI */
344 		disks += efi_disk_create_partitions(desc, if_typename,
345 						    desc->devnum, dev->name);
346 	}
347 #else
348 	int i, if_type;
349 
350 	/* Search for all available disk devices */
351 	for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
352 		const struct blk_driver *cur_drvr;
353 		const char *if_typename;
354 
355 		cur_drvr = blk_driver_lookup_type(if_type);
356 		if (!cur_drvr)
357 			continue;
358 
359 		if_typename = cur_drvr->if_typename;
360 		printf("Scanning disks on %s...\n", if_typename);
361 		for (i = 0; i < 4; i++) {
362 			struct blk_desc *desc;
363 			char devname[32] = { 0 }; /* dp->str is u16[32] long */
364 
365 			desc = blk_get_devnum_by_type(if_type, i);
366 			if (!desc)
367 				continue;
368 			if (desc->type == DEV_TYPE_UNKNOWN)
369 				continue;
370 
371 			snprintf(devname, sizeof(devname), "%s%d",
372 				 if_typename, i);
373 
374 			/* Add block device for the full device */
375 			efi_disk_add_dev(devname, if_typename, desc, i, 0, 0);
376 			disks++;
377 
378 			/* Partitions show up as block devices in EFI */
379 			disks += efi_disk_create_partitions(desc, if_typename,
380 							    i, devname);
381 		}
382 	}
383 #endif
384 	printf("Found %d disks\n", disks);
385 
386 	return 0;
387 }
388