xref: /openbmc/u-boot/lib/efi_loader/efi_disk.c (revision b8a6d677)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  EFI application disk support
4  *
5  *  Copyright (c) 2016 Alexander Graf
6  */
7 
8 #include <common.h>
9 #include <blk.h>
10 #include <dm.h>
11 #include <efi_loader.h>
12 #include <inttypes.h>
13 #include <part.h>
14 #include <malloc.h>
15 
16 const efi_guid_t efi_block_io_guid = BLOCK_IO_GUID;
17 
18 struct efi_disk_obj {
19 	/* Generic EFI object parent class data */
20 	struct efi_object parent;
21 	/* EFI Interface callback struct for block I/O */
22 	struct efi_block_io ops;
23 	/* U-Boot ifname for block device */
24 	const char *ifname;
25 	/* U-Boot dev_index for block device */
26 	int dev_index;
27 	/* EFI Interface Media descriptor struct, referenced by ops */
28 	struct efi_block_io_media media;
29 	/* EFI device path to this block device */
30 	struct efi_device_path *dp;
31 	/* partition # */
32 	unsigned int part;
33 	/* handle to filesys proto (for partition objects) */
34 	struct efi_simple_file_system_protocol *volume;
35 	/* Offset into disk for simple partitions */
36 	lbaint_t offset;
37 	/* Internal block device */
38 	struct blk_desc *desc;
39 };
40 
41 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
42 			char extended_verification)
43 {
44 	EFI_ENTRY("%p, %x", this, extended_verification);
45 	return EFI_EXIT(EFI_DEVICE_ERROR);
46 }
47 
48 enum efi_disk_direction {
49 	EFI_DISK_READ,
50 	EFI_DISK_WRITE,
51 };
52 
53 static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
54 			u32 media_id, u64 lba, unsigned long buffer_size,
55 			void *buffer, enum efi_disk_direction direction)
56 {
57 	struct efi_disk_obj *diskobj;
58 	struct blk_desc *desc;
59 	int blksz;
60 	int blocks;
61 	unsigned long n;
62 
63 	diskobj = container_of(this, struct efi_disk_obj, ops);
64 	desc = (struct blk_desc *) diskobj->desc;
65 	blksz = desc->blksz;
66 	blocks = buffer_size / blksz;
67 	lba += diskobj->offset;
68 
69 	debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
70 	      __LINE__, blocks, lba, blksz, direction);
71 
72 	/* We only support full block access */
73 	if (buffer_size & (blksz - 1))
74 		return EFI_DEVICE_ERROR;
75 
76 	if (direction == EFI_DISK_READ)
77 		n = blk_dread(desc, lba, blocks, buffer);
78 	else
79 		n = blk_dwrite(desc, lba, blocks, buffer);
80 
81 	/* We don't do interrupts, so check for timers cooperatively */
82 	efi_timer_check();
83 
84 	debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
85 
86 	if (n != blocks)
87 		return EFI_DEVICE_ERROR;
88 
89 	return EFI_SUCCESS;
90 }
91 
92 static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
93 			u32 media_id, u64 lba, efi_uintn_t buffer_size,
94 			void *buffer)
95 {
96 	void *real_buffer = buffer;
97 	efi_status_t r;
98 
99 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
100 	if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
101 		r = efi_disk_read_blocks(this, media_id, lba,
102 			EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
103 		if (r != EFI_SUCCESS)
104 			return r;
105 		return efi_disk_read_blocks(this, media_id, lba +
106 			EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
107 			buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
108 			buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
109 	}
110 
111 	real_buffer = efi_bounce_buffer;
112 #endif
113 
114 	EFI_ENTRY("%p, %x, %" PRIx64 ", %zx, %p", this, media_id, lba,
115 		  buffer_size, buffer);
116 
117 	r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
118 			       EFI_DISK_READ);
119 
120 	/* Copy from bounce buffer to real buffer if necessary */
121 	if ((r == EFI_SUCCESS) && (real_buffer != buffer))
122 		memcpy(buffer, real_buffer, buffer_size);
123 
124 	return EFI_EXIT(r);
125 }
126 
127 static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
128 			u32 media_id, u64 lba, efi_uintn_t buffer_size,
129 			void *buffer)
130 {
131 	void *real_buffer = buffer;
132 	efi_status_t r;
133 
134 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
135 	if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
136 		r = efi_disk_write_blocks(this, media_id, lba,
137 			EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
138 		if (r != EFI_SUCCESS)
139 			return r;
140 		return efi_disk_write_blocks(this, media_id, lba +
141 			EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
142 			buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
143 			buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
144 	}
145 
146 	real_buffer = efi_bounce_buffer;
147 #endif
148 
149 	EFI_ENTRY("%p, %x, %" PRIx64 ", %zx, %p", this, media_id, lba,
150 		  buffer_size, buffer);
151 
152 	/* Populate bounce buffer if necessary */
153 	if (real_buffer != buffer)
154 		memcpy(real_buffer, buffer, buffer_size);
155 
156 	r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
157 			       EFI_DISK_WRITE);
158 
159 	return EFI_EXIT(r);
160 }
161 
162 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
163 {
164 	/* We always write synchronously */
165 	EFI_ENTRY("%p", this);
166 	return EFI_EXIT(EFI_SUCCESS);
167 }
168 
169 static const struct efi_block_io block_io_disk_template = {
170 	.reset = &efi_disk_reset,
171 	.read_blocks = &efi_disk_read_blocks,
172 	.write_blocks = &efi_disk_write_blocks,
173 	.flush_blocks = &efi_disk_flush_blocks,
174 };
175 
176 /*
177  * Get the simple file system protocol for a file device path.
178  *
179  * The full path provided is split into device part and into a file
180  * part. The device part is used to find the handle on which the
181  * simple file system protocol is installed.
182  *
183  * @full_path	device path including device and file
184  * @return	simple file system protocol
185  */
186 struct efi_simple_file_system_protocol *
187 efi_fs_from_path(struct efi_device_path *full_path)
188 {
189 	struct efi_object *efiobj;
190 	struct efi_handler *handler;
191 	struct efi_device_path *device_path;
192 	struct efi_device_path *file_path;
193 	efi_status_t ret;
194 
195 	/* Split the path into a device part and a file part */
196 	ret = efi_dp_split_file_path(full_path, &device_path, &file_path);
197 	if (ret != EFI_SUCCESS)
198 		return NULL;
199 	efi_free_pool(file_path);
200 
201 	/* Get the EFI object for the partition */
202 	efiobj = efi_dp_find_obj(device_path, NULL);
203 	efi_free_pool(device_path);
204 	if (!efiobj)
205 		return NULL;
206 
207 	/* Find the simple file system protocol */
208 	ret = efi_search_protocol(efiobj, &efi_simple_file_system_protocol_guid,
209 				  &handler);
210 	if (ret != EFI_SUCCESS)
211 		return NULL;
212 
213 	/* Return the simple file system protocol for the partition */
214 	return handler->protocol_interface;
215 }
216 
217 /*
218  * Create a handle for a partition or disk
219  *
220  * @parent	parent handle
221  * @dp_parent	parent device path
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  * @return	disk object
227  */
228 static efi_status_t efi_disk_add_dev(
229 				efi_handle_t parent,
230 				struct efi_device_path *dp_parent,
231 				const char *if_typename,
232 				struct blk_desc *desc,
233 				int dev_index,
234 				lbaint_t offset,
235 				unsigned int part,
236 				struct efi_disk_obj **disk)
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 EFI_NOT_READY;
244 
245 	diskobj = calloc(1, sizeof(*diskobj));
246 	if (!diskobj)
247 		return EFI_OUT_OF_RESOURCES;
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 		return ret;
266 	ret = efi_add_protocol(diskobj->parent.handle, &efi_guid_device_path,
267 			       diskobj->dp);
268 	if (ret != EFI_SUCCESS)
269 		return ret;
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 			return ret;
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 	if (disk)
295 		*disk = diskobj;
296 	return EFI_SUCCESS;
297 }
298 
299 /*
300  * Create handles and protocols for the partitions of a block device
301  *
302  * @parent		handle of the parent disk
303  * @blk_desc		block device
304  * @if_typename		interface type
305  * @diskid		device number
306  * @pdevname		device name
307  * @return		number of partitions created
308  */
309 int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
310 			       const char *if_typename, int diskid,
311 			       const char *pdevname)
312 {
313 	int disks = 0;
314 	char devname[32] = { 0 }; /* dp->str is u16[32] long */
315 	disk_partition_t info;
316 	int part;
317 	struct efi_device_path *dp = NULL;
318 	efi_status_t ret;
319 	struct efi_handler *handler;
320 
321 	/* Get the device path of the parent */
322 	ret = efi_search_protocol(parent, &efi_guid_device_path, &handler);
323 	if (ret == EFI_SUCCESS)
324 		dp = handler->protocol_interface;
325 
326 	/* Add devices for each partition */
327 	for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
328 		if (part_get_info(desc, part, &info))
329 			continue;
330 		snprintf(devname, sizeof(devname), "%s:%d", pdevname,
331 			 part);
332 		ret = efi_disk_add_dev(parent, dp, if_typename, desc, diskid,
333 				       info.start, part, NULL);
334 		if (ret != EFI_SUCCESS) {
335 			printf("Adding partition %s failed\n", pdevname);
336 			continue;
337 		}
338 		disks++;
339 	}
340 
341 	return disks;
342 }
343 
344 /*
345  * U-Boot doesn't have a list of all online disk devices. So when running our
346  * EFI payload, we scan through all of the potentially available ones and
347  * store them in our object pool.
348  *
349  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
350  * Consider converting the code to look up devices as needed. The EFI device
351  * could be a child of the UCLASS_BLK block device, perhaps.
352  *
353  * This gets called from do_bootefi_exec().
354  */
355 efi_status_t efi_disk_register(void)
356 {
357 	struct efi_disk_obj *disk;
358 	int disks = 0;
359 	efi_status_t ret;
360 #ifdef CONFIG_BLK
361 	struct udevice *dev;
362 
363 	for (uclass_first_device_check(UCLASS_BLK, &dev); dev;
364 	     uclass_next_device_check(&dev)) {
365 		struct blk_desc *desc = dev_get_uclass_platdata(dev);
366 		const char *if_typename = blk_get_if_type_name(desc->if_type);
367 
368 		/* Add block device for the full device */
369 		printf("Scanning disk %s...\n", dev->name);
370 		ret = efi_disk_add_dev(NULL, NULL, if_typename,
371 					desc, desc->devnum, 0, 0, &disk);
372 		if (ret == EFI_NOT_READY) {
373 			printf("Disk %s not ready\n", dev->name);
374 			continue;
375 		}
376 		if (ret) {
377 			printf("ERROR: failure to add disk device %s, r = %lu\n",
378 			       dev->name, ret & ~EFI_ERROR_MASK);
379 			return ret;
380 		}
381 		disks++;
382 
383 		/* Partitions show up as block devices in EFI */
384 		disks += efi_disk_create_partitions(
385 					disk->parent.handle, desc, if_typename,
386 					desc->devnum, dev->name);
387 	}
388 #else
389 	int i, if_type;
390 
391 	/* Search for all available disk devices */
392 	for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
393 		const struct blk_driver *cur_drvr;
394 		const char *if_typename;
395 
396 		cur_drvr = blk_driver_lookup_type(if_type);
397 		if (!cur_drvr)
398 			continue;
399 
400 		if_typename = cur_drvr->if_typename;
401 		printf("Scanning disks on %s...\n", if_typename);
402 		for (i = 0; i < 4; i++) {
403 			struct blk_desc *desc;
404 			char devname[32] = { 0 }; /* dp->str is u16[32] long */
405 
406 			desc = blk_get_devnum_by_type(if_type, i);
407 			if (!desc)
408 				continue;
409 			if (desc->type == DEV_TYPE_UNKNOWN)
410 				continue;
411 
412 			snprintf(devname, sizeof(devname), "%s%d",
413 				 if_typename, i);
414 
415 			/* Add block device for the full device */
416 			ret = efi_disk_add_dev(NULL, NULL, if_typename, desc,
417 					       i, 0, 0, &disk);
418 			if (ret == EFI_NOT_READY) {
419 				printf("Disk %s not ready\n", devname);
420 				continue;
421 			}
422 			if (ret) {
423 				printf("ERROR: failure to add disk device %s, r = %lu\n",
424 				       devname, ret & ~EFI_ERROR_MASK);
425 				return ret;
426 			}
427 			disks++;
428 
429 			/* Partitions show up as block devices in EFI */
430 			disks += efi_disk_create_partitions(
431 						disk->parent.handle, desc,
432 						if_typename, i, devname);
433 		}
434 	}
435 #endif
436 	printf("Found %d disks\n", disks);
437 
438 	return EFI_SUCCESS;
439 }
440