xref: /openbmc/u-boot/lib/efi_loader/efi_disk.c (revision a818704b)
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_file_path *dp;
32 	/* Offset into disk for simple partitions */
33 	lbaint_t offset;
34 	/* Internal block device */
35 	const struct blk_desc *desc;
36 };
37 
38 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
39 			char extended_verification)
40 {
41 	EFI_ENTRY("%p, %x", this, extended_verification);
42 	return EFI_EXIT(EFI_DEVICE_ERROR);
43 }
44 
45 enum efi_disk_direction {
46 	EFI_DISK_READ,
47 	EFI_DISK_WRITE,
48 };
49 
50 static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
51 			u32 media_id, u64 lba, unsigned long buffer_size,
52 			void *buffer, enum efi_disk_direction direction)
53 {
54 	struct efi_disk_obj *diskobj;
55 	struct blk_desc *desc;
56 	int blksz;
57 	int blocks;
58 	unsigned long n;
59 
60 	diskobj = container_of(this, struct efi_disk_obj, ops);
61 	desc = (struct blk_desc *) diskobj->desc;
62 	blksz = desc->blksz;
63 	blocks = buffer_size / blksz;
64 	lba += diskobj->offset;
65 
66 	debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
67 	      __LINE__, blocks, lba, blksz, direction);
68 
69 	/* We only support full block access */
70 	if (buffer_size & (blksz - 1))
71 		return EFI_DEVICE_ERROR;
72 
73 	if (direction == EFI_DISK_READ)
74 		n = blk_dread(desc, lba, blocks, buffer);
75 	else
76 		n = blk_dwrite(desc, lba, blocks, buffer);
77 
78 	/* We don't do interrupts, so check for timers cooperatively */
79 	efi_timer_check();
80 
81 	debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
82 
83 	if (n != blocks)
84 		return EFI_DEVICE_ERROR;
85 
86 	return EFI_SUCCESS;
87 }
88 
89 static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
90 			u32 media_id, u64 lba, unsigned long buffer_size,
91 			void *buffer)
92 {
93 	void *real_buffer = buffer;
94 	efi_status_t r;
95 
96 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
97 	if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
98 		r = efi_disk_read_blocks(this, media_id, lba,
99 			EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
100 		if (r != EFI_SUCCESS)
101 			return r;
102 		return efi_disk_read_blocks(this, media_id, lba +
103 			EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
104 			buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
105 			buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
106 	}
107 
108 	real_buffer = efi_bounce_buffer;
109 #endif
110 
111 	EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
112 		  buffer_size, buffer);
113 
114 	r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
115 			       EFI_DISK_READ);
116 
117 	/* Copy from bounce buffer to real buffer if necessary */
118 	if ((r == EFI_SUCCESS) && (real_buffer != buffer))
119 		memcpy(buffer, real_buffer, buffer_size);
120 
121 	return EFI_EXIT(r);
122 }
123 
124 static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
125 			u32 media_id, u64 lba, unsigned long buffer_size,
126 			void *buffer)
127 {
128 	void *real_buffer = buffer;
129 	efi_status_t r;
130 
131 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
132 	if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
133 		r = efi_disk_write_blocks(this, media_id, lba,
134 			EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
135 		if (r != EFI_SUCCESS)
136 			return r;
137 		return efi_disk_write_blocks(this, media_id, lba +
138 			EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
139 			buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
140 			buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
141 	}
142 
143 	real_buffer = efi_bounce_buffer;
144 #endif
145 
146 	EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
147 		  buffer_size, buffer);
148 
149 	/* Populate bounce buffer if necessary */
150 	if (real_buffer != buffer)
151 		memcpy(real_buffer, buffer, buffer_size);
152 
153 	r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
154 			       EFI_DISK_WRITE);
155 
156 	return EFI_EXIT(r);
157 }
158 
159 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
160 {
161 	/* We always write synchronously */
162 	EFI_ENTRY("%p", this);
163 	return EFI_EXIT(EFI_SUCCESS);
164 }
165 
166 static const struct efi_block_io block_io_disk_template = {
167 	.reset = &efi_disk_reset,
168 	.read_blocks = &efi_disk_read_blocks,
169 	.write_blocks = &efi_disk_write_blocks,
170 	.flush_blocks = &efi_disk_flush_blocks,
171 };
172 
173 static void efi_disk_add_dev(const char *name,
174 			     const char *if_typename,
175 			     const struct blk_desc *desc,
176 			     int dev_index,
177 			     lbaint_t offset)
178 {
179 	struct efi_disk_obj *diskobj;
180 	struct efi_device_path_file_path *dp;
181 	int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
182 
183 	/* Don't add empty devices */
184 	if (!desc->lba)
185 		return;
186 
187 	diskobj = calloc(1, objlen);
188 
189 	/* Fill in object data */
190 	dp = (void *)&diskobj[1];
191 	diskobj->parent.protocols[0].guid = &efi_block_io_guid;
192 	diskobj->parent.protocols[0].protocol_interface = &diskobj->ops;
193 	diskobj->parent.protocols[1].guid = &efi_guid_device_path;
194 	diskobj->parent.protocols[1].protocol_interface = dp;
195 	diskobj->parent.handle = diskobj;
196 	diskobj->ops = block_io_disk_template;
197 	diskobj->ifname = if_typename;
198 	diskobj->dev_index = dev_index;
199 	diskobj->offset = offset;
200 	diskobj->desc = desc;
201 
202 	/* Fill in EFI IO Media info (for read/write callbacks) */
203 	diskobj->media.removable_media = desc->removable;
204 	diskobj->media.media_present = 1;
205 	diskobj->media.block_size = desc->blksz;
206 	diskobj->media.io_align = desc->blksz;
207 	diskobj->media.last_block = desc->lba - offset;
208 	diskobj->ops.media = &diskobj->media;
209 
210 	/* Fill in device path */
211 	diskobj->dp = dp;
212 	dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
213 	dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
214 	dp[0].dp.length = sizeof(*dp);
215 	ascii2unicode(dp[0].str, name);
216 
217 	dp[1].dp.type = DEVICE_PATH_TYPE_END;
218 	dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
219 	dp[1].dp.length = sizeof(*dp);
220 
221 	/* Hook up to the device list */
222 	list_add_tail(&diskobj->parent.link, &efi_obj_list);
223 }
224 
225 static int efi_disk_create_eltorito(struct blk_desc *desc,
226 				    const char *if_typename,
227 				    int diskid,
228 				    const char *pdevname)
229 {
230 	int disks = 0;
231 #if CONFIG_IS_ENABLED(ISO_PARTITION)
232 	char devname[32] = { 0 }; /* dp->str is u16[32] long */
233 	disk_partition_t info;
234 	int part = 1;
235 
236 	if (desc->part_type != PART_TYPE_ISO)
237 		return 0;
238 
239 	while (!part_get_info(desc, part, &info)) {
240 		snprintf(devname, sizeof(devname), "%s:%d", pdevname,
241 			 part);
242 		efi_disk_add_dev(devname, if_typename, desc, diskid,
243 				 info.start);
244 		part++;
245 		disks++;
246 	}
247 #endif
248 
249 	return disks;
250 }
251 
252 /*
253  * U-Boot doesn't have a list of all online disk devices. So when running our
254  * EFI payload, we scan through all of the potentially available ones and
255  * store them in our object pool.
256  *
257  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
258  * Consider converting the code to look up devices as needed. The EFI device
259  * could be a child of the UCLASS_BLK block device, perhaps.
260  *
261  * This gets called from do_bootefi_exec().
262  */
263 int efi_disk_register(void)
264 {
265 	int disks = 0;
266 #ifdef CONFIG_BLK
267 	struct udevice *dev;
268 
269 	for (uclass_first_device_check(UCLASS_BLK, &dev);
270 	     dev;
271 	     uclass_next_device_check(&dev)) {
272 		struct blk_desc *desc = dev_get_uclass_platdata(dev);
273 		const char *if_typename = dev->driver->name;
274 
275 		printf("Scanning disk %s...\n", dev->name);
276 		efi_disk_add_dev(dev->name, if_typename, desc, desc->devnum, 0);
277 		disks++;
278 
279 		/*
280 		* El Torito images show up as block devices in an EFI world,
281 		* so let's create them here
282 		*/
283 		disks += efi_disk_create_eltorito(desc, if_typename,
284 						  desc->devnum, dev->name);
285 	}
286 #else
287 	int i, if_type;
288 
289 	/* Search for all available disk devices */
290 	for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
291 		const struct blk_driver *cur_drvr;
292 		const char *if_typename;
293 
294 		cur_drvr = blk_driver_lookup_type(if_type);
295 		if (!cur_drvr)
296 			continue;
297 
298 		if_typename = cur_drvr->if_typename;
299 		printf("Scanning disks on %s...\n", if_typename);
300 		for (i = 0; i < 4; i++) {
301 			struct blk_desc *desc;
302 			char devname[32] = { 0 }; /* dp->str is u16[32] long */
303 
304 			desc = blk_get_devnum_by_type(if_type, i);
305 			if (!desc)
306 				continue;
307 			if (desc->type == DEV_TYPE_UNKNOWN)
308 				continue;
309 
310 			snprintf(devname, sizeof(devname), "%s%d",
311 				 if_typename, i);
312 			efi_disk_add_dev(devname, if_typename, desc, i, 0);
313 			disks++;
314 
315 			/*
316 			 * El Torito images show up as block devices
317 			 * in an EFI world, so let's create them here
318 			 */
319 			disks += efi_disk_create_eltorito(desc, if_typename,
320 							  i, devname);
321 		}
322 	}
323 #endif
324 	printf("Found %d disks\n", disks);
325 
326 	return 0;
327 }
328