xref: /openbmc/u-boot/lib/efi_loader/efi_disk.c (revision dcb11959)
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  * Find filesystem from a device-path.  The passed in path 'p' probably
179  * contains one or more /File(name) nodes, so the comparison stops at
180  * the first /File() node, and returns the pointer to that via 'rp'.
181  * This is mostly intended to be a helper to map a device-path to an
182  * efi_file_handle object.
183  */
184 struct efi_simple_file_system_protocol *
185 efi_fs_from_path(struct efi_device_path *fp)
186 {
187 	struct efi_object *efiobj;
188 	struct efi_disk_obj *diskobj;
189 
190 	efiobj = efi_dp_find_obj(fp, NULL);
191 	if (!efiobj)
192 		return NULL;
193 
194 	diskobj = container_of(efiobj, struct efi_disk_obj, parent);
195 
196 	return diskobj->volume;
197 }
198 
199 /*
200  * Create a device for a disk
201  *
202  * @name	not used
203  * @if_typename interface name for block device
204  * @desc	internal block device
205  * @dev_index   device index for block device
206  * @offset	offset into disk for simple partitions
207  */
208 static void efi_disk_add_dev(const char *name,
209 			     const char *if_typename,
210 			     struct blk_desc *desc,
211 			     int dev_index,
212 			     lbaint_t offset,
213 			     unsigned int part)
214 {
215 	struct efi_disk_obj *diskobj;
216 	efi_status_t ret;
217 
218 	/* Don't add empty devices */
219 	if (!desc->lba)
220 		return;
221 
222 	diskobj = calloc(1, sizeof(*diskobj));
223 	if (!diskobj)
224 		goto out_of_memory;
225 
226 	/* Hook up to the device list */
227 	efi_add_handle(&diskobj->parent);
228 
229 	/* Fill in object data */
230 	diskobj->dp = efi_dp_from_part(desc, part);
231 	diskobj->part = part;
232 	ret = efi_add_protocol(diskobj->parent.handle, &efi_block_io_guid,
233 			       &diskobj->ops);
234 	if (ret != EFI_SUCCESS)
235 		goto out_of_memory;
236 	ret = efi_add_protocol(diskobj->parent.handle, &efi_guid_device_path,
237 			       diskobj->dp);
238 	if (ret != EFI_SUCCESS)
239 		goto out_of_memory;
240 	if (part >= 1) {
241 		diskobj->volume = efi_simple_file_system(desc, part,
242 							 diskobj->dp);
243 		ret = efi_add_protocol(diskobj->parent.handle,
244 				       &efi_simple_file_system_protocol_guid,
245 				       &diskobj->volume);
246 		if (ret != EFI_SUCCESS)
247 			goto out_of_memory;
248 	}
249 	diskobj->ops = block_io_disk_template;
250 	diskobj->ifname = if_typename;
251 	diskobj->dev_index = dev_index;
252 	diskobj->offset = offset;
253 	diskobj->desc = desc;
254 
255 	/* Fill in EFI IO Media info (for read/write callbacks) */
256 	diskobj->media.removable_media = desc->removable;
257 	diskobj->media.media_present = 1;
258 	diskobj->media.block_size = desc->blksz;
259 	diskobj->media.io_align = desc->blksz;
260 	diskobj->media.last_block = desc->lba - offset;
261 	if (part != 0)
262 		diskobj->media.logical_partition = 1;
263 	diskobj->ops.media = &diskobj->media;
264 	return;
265 out_of_memory:
266 	printf("ERROR: Out of memory\n");
267 }
268 
269 static int efi_disk_create_partitions(struct blk_desc *desc,
270 				      const char *if_typename,
271 				      int diskid,
272 				      const char *pdevname)
273 {
274 	int disks = 0;
275 	char devname[32] = { 0 }; /* dp->str is u16[32] long */
276 	disk_partition_t info;
277 	int part;
278 
279 	/* Add devices for each partition */
280 	for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
281 		if (part_get_info(desc, part, &info))
282 			continue;
283 		snprintf(devname, sizeof(devname), "%s:%d", pdevname,
284 			 part);
285 		efi_disk_add_dev(devname, if_typename, desc, diskid,
286 				 info.start, part);
287 		disks++;
288 	}
289 
290 	return disks;
291 }
292 
293 /*
294  * U-Boot doesn't have a list of all online disk devices. So when running our
295  * EFI payload, we scan through all of the potentially available ones and
296  * store them in our object pool.
297  *
298  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
299  * Consider converting the code to look up devices as needed. The EFI device
300  * could be a child of the UCLASS_BLK block device, perhaps.
301  *
302  * This gets called from do_bootefi_exec().
303  */
304 int efi_disk_register(void)
305 {
306 	int disks = 0;
307 #ifdef CONFIG_BLK
308 	struct udevice *dev;
309 
310 	for (uclass_first_device_check(UCLASS_BLK, &dev);
311 	     dev;
312 	     uclass_next_device_check(&dev)) {
313 		struct blk_desc *desc = dev_get_uclass_platdata(dev);
314 		const char *if_typename = dev->driver->name;
315 
316 		printf("Scanning disk %s...\n", dev->name);
317 
318 		/* Add block device for the full device */
319 		efi_disk_add_dev(dev->name, if_typename, desc,
320 				 desc->devnum, 0, 0);
321 
322 		disks++;
323 
324 		/* Partitions show up as block devices in EFI */
325 		disks += efi_disk_create_partitions(desc, if_typename,
326 						    desc->devnum, dev->name);
327 	}
328 #else
329 	int i, if_type;
330 
331 	/* Search for all available disk devices */
332 	for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
333 		const struct blk_driver *cur_drvr;
334 		const char *if_typename;
335 
336 		cur_drvr = blk_driver_lookup_type(if_type);
337 		if (!cur_drvr)
338 			continue;
339 
340 		if_typename = cur_drvr->if_typename;
341 		printf("Scanning disks on %s...\n", if_typename);
342 		for (i = 0; i < 4; i++) {
343 			struct blk_desc *desc;
344 			char devname[32] = { 0 }; /* dp->str is u16[32] long */
345 
346 			desc = blk_get_devnum_by_type(if_type, i);
347 			if (!desc)
348 				continue;
349 			if (desc->type == DEV_TYPE_UNKNOWN)
350 				continue;
351 
352 			snprintf(devname, sizeof(devname), "%s%d",
353 				 if_typename, i);
354 
355 			/* Add block device for the full device */
356 			efi_disk_add_dev(devname, if_typename, desc, i, 0, 0);
357 			disks++;
358 
359 			/* Partitions show up as block devices in EFI */
360 			disks += efi_disk_create_partitions(desc, if_typename,
361 							    i, devname);
362 		}
363 	}
364 #endif
365 	printf("Found %d disks\n", disks);
366 
367 	return 0;
368 }
369