xref: /openbmc/u-boot/lib/efi_loader/efi_disk.c (revision 9d922450)
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_open_block(void *handle,
39 			efi_guid_t *protocol, void **protocol_interface,
40 			void *agent_handle, void *controller_handle,
41 			uint32_t attributes)
42 {
43 	struct efi_disk_obj *diskobj = handle;
44 
45 	*protocol_interface = &diskobj->ops;
46 
47 	return EFI_SUCCESS;
48 }
49 
50 static efi_status_t EFIAPI efi_disk_open_dp(void *handle, efi_guid_t *protocol,
51 			void **protocol_interface, void *agent_handle,
52 			void *controller_handle, uint32_t attributes)
53 {
54 	struct efi_disk_obj *diskobj = handle;
55 
56 	*protocol_interface = diskobj->dp;
57 
58 	return EFI_SUCCESS;
59 }
60 
61 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
62 			char extended_verification)
63 {
64 	EFI_ENTRY("%p, %x", this, extended_verification);
65 	return EFI_EXIT(EFI_DEVICE_ERROR);
66 }
67 
68 enum efi_disk_direction {
69 	EFI_DISK_READ,
70 	EFI_DISK_WRITE,
71 };
72 
73 static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
74 			u32 media_id, u64 lba, unsigned long buffer_size,
75 			void *buffer, enum efi_disk_direction direction)
76 {
77 	struct efi_disk_obj *diskobj;
78 	struct blk_desc *desc;
79 	int blksz;
80 	int blocks;
81 	unsigned long n;
82 
83 	diskobj = container_of(this, struct efi_disk_obj, ops);
84 	desc = (struct blk_desc *) diskobj->desc;
85 	blksz = desc->blksz;
86 	blocks = buffer_size / blksz;
87 	lba += diskobj->offset;
88 
89 	debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
90 	      __LINE__, blocks, lba, blksz, direction);
91 
92 	/* We only support full block access */
93 	if (buffer_size & (blksz - 1))
94 		return EFI_EXIT(EFI_DEVICE_ERROR);
95 
96 	if (direction == EFI_DISK_READ)
97 		n = blk_dread(desc, lba, blocks, buffer);
98 	else
99 		n = blk_dwrite(desc, lba, blocks, buffer);
100 
101 	/* We don't do interrupts, so check for timers cooperatively */
102 	efi_timer_check();
103 
104 	debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
105 
106 	if (n != blocks)
107 		return EFI_EXIT(EFI_DEVICE_ERROR);
108 
109 	return EFI_EXIT(EFI_SUCCESS);
110 }
111 
112 static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
113 			u32 media_id, u64 lba, unsigned long buffer_size,
114 			void *buffer)
115 {
116 	void *real_buffer = buffer;
117 	efi_status_t r;
118 
119 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
120 	if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
121 		r = efi_disk_read_blocks(this, media_id, lba,
122 			EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
123 		if (r != EFI_SUCCESS)
124 			return r;
125 		return efi_disk_read_blocks(this, media_id, lba +
126 			EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
127 			buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
128 			buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
129 	}
130 
131 	real_buffer = efi_bounce_buffer;
132 #endif
133 
134 	EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
135 		  buffer_size, buffer);
136 
137 	r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
138 			       EFI_DISK_READ);
139 
140 	/* Copy from bounce buffer to real buffer if necessary */
141 	if ((r == EFI_SUCCESS) && (real_buffer != buffer))
142 		memcpy(buffer, real_buffer, buffer_size);
143 
144 	return EFI_EXIT(r);
145 }
146 
147 static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
148 			u32 media_id, u64 lba, unsigned long buffer_size,
149 			void *buffer)
150 {
151 	void *real_buffer = buffer;
152 	efi_status_t r;
153 
154 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
155 	if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
156 		r = efi_disk_write_blocks(this, media_id, lba,
157 			EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
158 		if (r != EFI_SUCCESS)
159 			return r;
160 		return efi_disk_write_blocks(this, media_id, lba +
161 			EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
162 			buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
163 			buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
164 	}
165 
166 	real_buffer = efi_bounce_buffer;
167 #endif
168 
169 	EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
170 		  buffer_size, buffer);
171 
172 	/* Populate bounce buffer if necessary */
173 	if (real_buffer != buffer)
174 		memcpy(real_buffer, buffer, buffer_size);
175 
176 	r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
177 			       EFI_DISK_WRITE);
178 
179 	return EFI_EXIT(r);
180 }
181 
182 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
183 {
184 	/* We always write synchronously */
185 	EFI_ENTRY("%p", this);
186 	return EFI_EXIT(EFI_SUCCESS);
187 }
188 
189 static const struct efi_block_io block_io_disk_template = {
190 	.reset = &efi_disk_reset,
191 	.read_blocks = &efi_disk_read_blocks,
192 	.write_blocks = &efi_disk_write_blocks,
193 	.flush_blocks = &efi_disk_flush_blocks,
194 };
195 
196 static void efi_disk_add_dev(const char *name,
197 			     const char *if_typename,
198 			     const struct blk_desc *desc,
199 			     int dev_index,
200 			     lbaint_t offset)
201 {
202 	struct efi_disk_obj *diskobj;
203 	struct efi_device_path_file_path *dp;
204 	int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
205 
206 	/* Don't add empty devices */
207 	if (!desc->lba)
208 		return;
209 
210 	diskobj = calloc(1, objlen);
211 
212 	/* Fill in object data */
213 	diskobj->parent.protocols[0].guid = &efi_block_io_guid;
214 	diskobj->parent.protocols[0].open = efi_disk_open_block;
215 	diskobj->parent.protocols[1].guid = &efi_guid_device_path;
216 	diskobj->parent.protocols[1].open = efi_disk_open_dp;
217 	diskobj->parent.handle = diskobj;
218 	diskobj->ops = block_io_disk_template;
219 	diskobj->ifname = if_typename;
220 	diskobj->dev_index = dev_index;
221 	diskobj->offset = offset;
222 	diskobj->desc = desc;
223 
224 	/* Fill in EFI IO Media info (for read/write callbacks) */
225 	diskobj->media.removable_media = desc->removable;
226 	diskobj->media.media_present = 1;
227 	diskobj->media.block_size = desc->blksz;
228 	diskobj->media.io_align = desc->blksz;
229 	diskobj->media.last_block = desc->lba - offset;
230 	diskobj->ops.media = &diskobj->media;
231 
232 	/* Fill in device path */
233 	dp = (void*)&diskobj[1];
234 	diskobj->dp = dp;
235 	dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
236 	dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
237 	dp[0].dp.length = sizeof(*dp);
238 	ascii2unicode(dp[0].str, name);
239 
240 	dp[1].dp.type = DEVICE_PATH_TYPE_END;
241 	dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
242 	dp[1].dp.length = sizeof(*dp);
243 
244 	/* Hook up to the device list */
245 	list_add_tail(&diskobj->parent.link, &efi_obj_list);
246 }
247 
248 static int efi_disk_create_eltorito(struct blk_desc *desc,
249 				    const char *if_typename,
250 				    int diskid,
251 				    const char *pdevname)
252 {
253 	int disks = 0;
254 #if CONFIG_IS_ENABLED(ISO_PARTITION)
255 	char devname[32] = { 0 }; /* dp->str is u16[32] long */
256 	disk_partition_t info;
257 	int part = 1;
258 
259 	if (desc->part_type != PART_TYPE_ISO)
260 		return 0;
261 
262 	while (!part_get_info(desc, part, &info)) {
263 		snprintf(devname, sizeof(devname), "%s:%d", pdevname,
264 			 part);
265 		efi_disk_add_dev(devname, if_typename, desc, diskid,
266 				 info.start);
267 		part++;
268 		disks++;
269 	}
270 #endif
271 
272 	return disks;
273 }
274 
275 /*
276  * U-Boot doesn't have a list of all online disk devices. So when running our
277  * EFI payload, we scan through all of the potentially available ones and
278  * store them in our object pool.
279  *
280  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
281  * Consider converting the code to look up devices as needed. The EFI device
282  * could be a child of the UCLASS_BLK block device, perhaps.
283  *
284  * This gets called from do_bootefi_exec().
285  */
286 int efi_disk_register(void)
287 {
288 	int disks = 0;
289 #ifdef CONFIG_BLK
290 	struct udevice *dev;
291 
292 	for (uclass_first_device(UCLASS_BLK, &dev);
293 	     dev;
294 	     uclass_next_device(&dev)) {
295 		struct blk_desc *desc = dev_get_uclass_platdata(dev);
296 		const char *if_typename = dev->driver->name;
297 
298 		printf("Scanning disk %s...\n", dev->name);
299 		efi_disk_add_dev(dev->name, if_typename, desc, desc->devnum, 0);
300 		disks++;
301 
302 		/*
303 		* El Torito images show up as block devices in an EFI world,
304 		* so let's create them here
305 		*/
306 		disks += efi_disk_create_eltorito(desc, if_typename,
307 						  desc->devnum, dev->name);
308 	}
309 #else
310 	int i, if_type;
311 
312 	/* Search for all available disk devices */
313 	for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
314 		const struct blk_driver *cur_drvr;
315 		const char *if_typename;
316 
317 		cur_drvr = blk_driver_lookup_type(if_type);
318 		if (!cur_drvr)
319 			continue;
320 
321 		if_typename = cur_drvr->if_typename;
322 		printf("Scanning disks on %s...\n", if_typename);
323 		for (i = 0; i < 4; i++) {
324 			struct blk_desc *desc;
325 			char devname[32] = { 0 }; /* dp->str is u16[32] long */
326 
327 			desc = blk_get_devnum_by_type(if_type, i);
328 			if (!desc)
329 				continue;
330 			if (desc->type == DEV_TYPE_UNKNOWN)
331 				continue;
332 
333 			snprintf(devname, sizeof(devname), "%s%d",
334 				 if_typename, i);
335 			efi_disk_add_dev(devname, if_typename, desc, i, 0);
336 			disks++;
337 
338 			/*
339 			 * El Torito images show up as block devices
340 			 * in an EFI world, so let's create them here
341 			 */
342 			disks += efi_disk_create_eltorito(desc, if_typename,
343 							  i, devname);
344 		}
345 	}
346 #endif
347 	printf("Found %d disks\n", disks);
348 
349 	return 0;
350 }
351