xref: /openbmc/u-boot/lib/efi_loader/efi_disk.c (revision 85231c08)
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 efi_status_t 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 				struct efi_disk_obj **disk)
238 {
239 	struct efi_disk_obj *diskobj;
240 	efi_status_t ret;
241 
242 	/* Don't add empty devices */
243 	if (!desc->lba)
244 		return EFI_NOT_READY;
245 
246 	diskobj = calloc(1, sizeof(*diskobj));
247 	if (!diskobj)
248 		return EFI_OUT_OF_RESOURCES;
249 
250 	/* Hook up to the device list */
251 	efi_add_handle(&diskobj->parent);
252 
253 	/* Fill in object data */
254 	if (part) {
255 		struct efi_device_path *node = efi_dp_part_node(desc, part);
256 
257 		diskobj->dp = efi_dp_append_node(dp_parent, node);
258 		efi_free_pool(node);
259 	} else {
260 		diskobj->dp = efi_dp_from_part(desc, part);
261 	}
262 	diskobj->part = part;
263 	ret = efi_add_protocol(diskobj->parent.handle, &efi_block_io_guid,
264 			       &diskobj->ops);
265 	if (ret != EFI_SUCCESS)
266 		return ret;
267 	ret = efi_add_protocol(diskobj->parent.handle, &efi_guid_device_path,
268 			       diskobj->dp);
269 	if (ret != EFI_SUCCESS)
270 		return ret;
271 	if (part >= 1) {
272 		diskobj->volume = efi_simple_file_system(desc, part,
273 							 diskobj->dp);
274 		ret = efi_add_protocol(diskobj->parent.handle,
275 				       &efi_simple_file_system_protocol_guid,
276 				       diskobj->volume);
277 		if (ret != EFI_SUCCESS)
278 			return ret;
279 	}
280 	diskobj->ops = block_io_disk_template;
281 	diskobj->ifname = if_typename;
282 	diskobj->dev_index = dev_index;
283 	diskobj->offset = offset;
284 	diskobj->desc = desc;
285 
286 	/* Fill in EFI IO Media info (for read/write callbacks) */
287 	diskobj->media.removable_media = desc->removable;
288 	diskobj->media.media_present = 1;
289 	diskobj->media.block_size = desc->blksz;
290 	diskobj->media.io_align = desc->blksz;
291 	diskobj->media.last_block = desc->lba - offset;
292 	if (part != 0)
293 		diskobj->media.logical_partition = 1;
294 	diskobj->ops.media = &diskobj->media;
295 	if (disk)
296 		*disk = diskobj;
297 	return EFI_SUCCESS;
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 		ret = efi_disk_add_dev(parent, dp, if_typename, desc, diskid,
334 				       info.start, part, NULL);
335 		if (ret != EFI_SUCCESS) {
336 			printf("Adding partition %s failed\n", pdevname);
337 			continue;
338 		}
339 		disks++;
340 	}
341 
342 	return disks;
343 }
344 
345 /*
346  * U-Boot doesn't have a list of all online disk devices. So when running our
347  * EFI payload, we scan through all of the potentially available ones and
348  * store them in our object pool.
349  *
350  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
351  * Consider converting the code to look up devices as needed. The EFI device
352  * could be a child of the UCLASS_BLK block device, perhaps.
353  *
354  * This gets called from do_bootefi_exec().
355  */
356 efi_status_t efi_disk_register(void)
357 {
358 	struct efi_disk_obj *disk;
359 	int disks = 0;
360 	efi_status_t ret;
361 #ifdef CONFIG_BLK
362 	struct udevice *dev;
363 
364 	for (uclass_first_device_check(UCLASS_BLK, &dev); dev;
365 	     uclass_next_device_check(&dev)) {
366 		struct blk_desc *desc = dev_get_uclass_platdata(dev);
367 		const char *if_typename = blk_get_if_type_name(desc->if_type);
368 
369 		/* Add block device for the full device */
370 		printf("Scanning disk %s...\n", dev->name);
371 		ret = efi_disk_add_dev(NULL, NULL, if_typename,
372 					desc, desc->devnum, 0, 0, &disk);
373 		if (ret == EFI_NOT_READY) {
374 			printf("Disk %s not ready\n", dev->name);
375 			continue;
376 		}
377 		if (ret) {
378 			printf("ERROR: failure to add disk device %s, r = %lu\n",
379 			       dev->name, ret & ~EFI_ERROR_MASK);
380 			return ret;
381 		}
382 		disks++;
383 
384 		/* Partitions show up as block devices in EFI */
385 		disks += efi_disk_create_partitions(
386 					disk->parent.handle, desc, if_typename,
387 					desc->devnum, dev->name);
388 	}
389 #else
390 	int i, if_type;
391 
392 	/* Search for all available disk devices */
393 	for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
394 		const struct blk_driver *cur_drvr;
395 		const char *if_typename;
396 
397 		cur_drvr = blk_driver_lookup_type(if_type);
398 		if (!cur_drvr)
399 			continue;
400 
401 		if_typename = cur_drvr->if_typename;
402 		printf("Scanning disks on %s...\n", if_typename);
403 		for (i = 0; i < 4; i++) {
404 			struct blk_desc *desc;
405 			char devname[32] = { 0 }; /* dp->str is u16[32] long */
406 
407 			desc = blk_get_devnum_by_type(if_type, i);
408 			if (!desc)
409 				continue;
410 			if (desc->type == DEV_TYPE_UNKNOWN)
411 				continue;
412 
413 			snprintf(devname, sizeof(devname), "%s%d",
414 				 if_typename, i);
415 
416 			/* Add block device for the full device */
417 			ret = efi_disk_add_dev(NULL, NULL, if_typename, desc,
418 					       i, 0, 0, &disk);
419 			if (ret == EFI_NOT_READY) {
420 				printf("Disk %s not ready\n", devname);
421 				continue;
422 			}
423 			if (ret) {
424 				printf("ERROR: failure to add disk device %s, r = %lu\n",
425 				       devname, ret & ~EFI_ERROR_MASK);
426 				return ret;
427 			}
428 			disks++;
429 
430 			/* Partitions show up as block devices in EFI */
431 			disks += efi_disk_create_partitions(
432 						disk->parent.handle, desc,
433 						if_typename, i, devname);
434 		}
435 	}
436 #endif
437 	printf("Found %d disks\n", disks);
438 
439 	return EFI_SUCCESS;
440 }
441