xref: /openbmc/u-boot/lib/efi_loader/efi_disk.c (revision 16121280)
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 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, efi_uintn_t 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 ", %zx, %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, efi_uintn_t 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 ", %zx, %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 handle for a partition or disk
220  *
221  * @parent	parent handle
222  * @dp_parent	parent device path
223  * @if_typename interface name for block device
224  * @desc	internal block device
225  * @dev_index   device index for block device
226  * @offset	offset into disk for simple partitions
227  * @return	disk object
228  */
229 static struct efi_disk_obj *efi_disk_add_dev(
230 				efi_handle_t parent,
231 				struct efi_device_path *dp_parent,
232 				const char *if_typename,
233 				struct blk_desc *desc,
234 				int dev_index,
235 				lbaint_t offset,
236 				unsigned int part)
237 {
238 	struct efi_disk_obj *diskobj;
239 	efi_status_t ret;
240 
241 	/* Don't add empty devices */
242 	if (!desc->lba)
243 		return NULL;
244 
245 	diskobj = calloc(1, sizeof(*diskobj));
246 	if (!diskobj)
247 		goto out_of_memory;
248 
249 	/* Hook up to the device list */
250 	efi_add_handle(&diskobj->parent);
251 
252 	/* Fill in object data */
253 	if (part) {
254 		struct efi_device_path *node = efi_dp_part_node(desc, part);
255 
256 		diskobj->dp = efi_dp_append_node(dp_parent, node);
257 		efi_free_pool(node);
258 	} else {
259 		diskobj->dp = efi_dp_from_part(desc, part);
260 	}
261 	diskobj->part = part;
262 	ret = efi_add_protocol(diskobj->parent.handle, &efi_block_io_guid,
263 			       &diskobj->ops);
264 	if (ret != EFI_SUCCESS)
265 		goto out_of_memory;
266 	ret = efi_add_protocol(diskobj->parent.handle, &efi_guid_device_path,
267 			       diskobj->dp);
268 	if (ret != EFI_SUCCESS)
269 		goto out_of_memory;
270 	if (part >= 1) {
271 		diskobj->volume = efi_simple_file_system(desc, part,
272 							 diskobj->dp);
273 		ret = efi_add_protocol(diskobj->parent.handle,
274 				       &efi_simple_file_system_protocol_guid,
275 				       diskobj->volume);
276 		if (ret != EFI_SUCCESS)
277 			goto out_of_memory;
278 	}
279 	diskobj->ops = block_io_disk_template;
280 	diskobj->ifname = if_typename;
281 	diskobj->dev_index = dev_index;
282 	diskobj->offset = offset;
283 	diskobj->desc = desc;
284 
285 	/* Fill in EFI IO Media info (for read/write callbacks) */
286 	diskobj->media.removable_media = desc->removable;
287 	diskobj->media.media_present = 1;
288 	diskobj->media.block_size = desc->blksz;
289 	diskobj->media.io_align = desc->blksz;
290 	diskobj->media.last_block = desc->lba - offset;
291 	if (part != 0)
292 		diskobj->media.logical_partition = 1;
293 	diskobj->ops.media = &diskobj->media;
294 	return diskobj;
295 out_of_memory:
296 	printf("ERROR: Out of memory\n");
297 	return NULL;
298 }
299 
300 /*
301  * Create handles and protocols for the partitions of a block device
302  *
303  * @parent		handle of the parent disk
304  * @blk_desc		block device
305  * @if_typename		interface type
306  * @diskid		device number
307  * @pdevname		device name
308  * @return		number of partitions created
309  */
310 int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
311 			       const char *if_typename, int diskid,
312 			       const char *pdevname)
313 {
314 	int disks = 0;
315 	char devname[32] = { 0 }; /* dp->str is u16[32] long */
316 	disk_partition_t info;
317 	int part;
318 	struct efi_device_path *dp = NULL;
319 	efi_status_t ret;
320 	struct efi_handler *handler;
321 
322 	/* Get the device path of the parent */
323 	ret = efi_search_protocol(parent, &efi_guid_device_path, &handler);
324 	if (ret == EFI_SUCCESS)
325 		dp = handler->protocol_interface;
326 
327 	/* Add devices for each partition */
328 	for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
329 		if (part_get_info(desc, part, &info))
330 			continue;
331 		snprintf(devname, sizeof(devname), "%s:%d", pdevname,
332 			 part);
333 		efi_disk_add_dev(parent, dp, if_typename, desc, diskid,
334 				 info.start, part);
335 		disks++;
336 	}
337 
338 	return disks;
339 }
340 
341 /*
342  * U-Boot doesn't have a list of all online disk devices. So when running our
343  * EFI payload, we scan through all of the potentially available ones and
344  * store them in our object pool.
345  *
346  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
347  * Consider converting the code to look up devices as needed. The EFI device
348  * could be a child of the UCLASS_BLK block device, perhaps.
349  *
350  * This gets called from do_bootefi_exec().
351  */
352 int efi_disk_register(void)
353 {
354 	struct efi_disk_obj *disk;
355 	int disks = 0;
356 #ifdef CONFIG_BLK
357 	struct udevice *dev;
358 
359 	for (uclass_first_device_check(UCLASS_BLK, &dev);
360 	     dev;
361 	     uclass_next_device_check(&dev)) {
362 		struct blk_desc *desc = dev_get_uclass_platdata(dev);
363 		const char *if_typename = blk_get_if_type_name(desc->if_type);
364 
365 		printf("Scanning disk %s...\n", dev->name);
366 
367 		/* Add block device for the full device */
368 		disk = efi_disk_add_dev(NULL, NULL, if_typename,
369 					desc, desc->devnum, 0, 0);
370 		if (!disk)
371 			return -ENOMEM;
372 		disks++;
373 
374 		/* Partitions show up as block devices in EFI */
375 		disks += efi_disk_create_partitions(
376 					disk->parent.handle, desc, if_typename,
377 					desc->devnum, dev->name);
378 	}
379 #else
380 	int i, if_type;
381 
382 	/* Search for all available disk devices */
383 	for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
384 		const struct blk_driver *cur_drvr;
385 		const char *if_typename;
386 
387 		cur_drvr = blk_driver_lookup_type(if_type);
388 		if (!cur_drvr)
389 			continue;
390 
391 		if_typename = cur_drvr->if_typename;
392 		printf("Scanning disks on %s...\n", if_typename);
393 		for (i = 0; i < 4; i++) {
394 			struct blk_desc *desc;
395 			char devname[32] = { 0 }; /* dp->str is u16[32] long */
396 
397 			desc = blk_get_devnum_by_type(if_type, i);
398 			if (!desc)
399 				continue;
400 			if (desc->type == DEV_TYPE_UNKNOWN)
401 				continue;
402 
403 			snprintf(devname, sizeof(devname), "%s%d",
404 				 if_typename, i);
405 
406 			/* Add block device for the full device */
407 			disk = efi_disk_add_dev(NULL, NULL, if_typename, desc,
408 						i, 0, 0);
409 			if (!disk)
410 				return -ENOMEM;
411 			disks++;
412 
413 			/* Partitions show up as block devices in EFI */
414 			disks += efi_disk_create_partitions(
415 						disk->parent.handle, desc,
416 						if_typename, i, devname);
417 		}
418 	}
419 #endif
420 	printf("Found %d disks\n", disks);
421 
422 	return 0;
423 }
424