1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * EFI-app board implementation
4 *
5 * Copyright 2023 Google LLC
6 * Written by Simon Glass <sjg@chromium.org>
7 */
8
9#include <dm.h>
10#include <efi.h>
11#include <efi_api.h>
12#include <errno.h>
13#include <malloc.h>
14#include <asm/global_data.h>
15#include <dm/device-internal.h>
16#include <dm/root.h>
17#include <linux/types.h>
18
19DECLARE_GLOBAL_DATA_PTR;
20
21/**
22 * efi_bind_block() - bind a new block device to an EFI device
23 *
24 * Binds a new top-level EFI_MEDIA device as well as a child block device so
25 * that the block device can be accessed in U-Boot.
26 *
27 * The device can then be accessed using 'part list efi 0', 'fat ls efi 0:1',
28 * for example, just like any other interface type.
29 *
30 * @handle: handle of the controller on which this driver is installed
31 * @blkio: block io protocol proxied by this driver
32 * @device_path: EFI device path structure for this
33 * @len: Length of @device_path in bytes
34 * @devp: Returns the bound device
35 * Return: 0 if OK, -ve on error
36 */
37int efi_bind_block(efi_handle_t handle, struct efi_block_io *blkio,
38		   struct efi_device_path *device_path, int len,
39		   struct udevice **devp)
40{
41	struct efi_media_plat plat;
42	struct udevice *dev;
43	char name[18];
44	int ret;
45
46	plat.handle = handle;
47	plat.blkio = blkio;
48	plat.device_path = malloc(device_path->length);
49	if (!plat.device_path)
50		return log_msg_ret("path", -ENOMEM);
51	memcpy(plat.device_path, device_path, device_path->length);
52	ret = device_bind(dm_root(), DM_DRIVER_GET(efi_media), "efi_media",
53			  &plat, ofnode_null(), &dev);
54	if (ret)
55		return log_msg_ret("bind", ret);
56
57	snprintf(name, sizeof(name), "efi_media_%x", dev_seq(dev));
58	device_set_name(dev, name);
59	*devp = dev;
60
61	return 0;
62}
63
64/**
65 * devpath_is_partition() - Figure out if a device path is a partition
66 *
67 * Checks if a device path refers to a partition on some media device. This
68 * works by checking for a valid partition number in a hard-driver media device
69 * as the final component of the device path.
70 *
71 * @path:	device path
72 * Return:	true if a partition, false if not
73 *		(e.g. it might be media which contains partitions)
74 */
75static bool devpath_is_partition(const struct efi_device_path *path)
76{
77	const struct efi_device_path *p;
78	bool was_part = false;
79
80	for (p = path; p->type != DEVICE_PATH_TYPE_END;
81	     p = (void *)p + p->length) {
82		was_part = false;
83		if (p->type == DEVICE_PATH_TYPE_MEDIA_DEVICE &&
84		    p->sub_type == DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH) {
85			struct efi_device_path_hard_drive_path *hd =
86				(void *)path;
87
88			if (hd->partition_number)
89				was_part = true;
90		}
91	}
92
93	return was_part;
94}
95
96/**
97 * setup_block() - Find all block devices and setup EFI devices for them
98 *
99 * Partitions are ignored, since U-Boot has partition handling. Errors with
100 * particular devices produce a warning but execution continues to try to
101 * find others.
102 *
103 * Return: 0 if found, -ENOSYS if there is no boot-services table, -ENOTSUPP
104 *	if a required protocol is not supported
105 */
106static int setup_block(void)
107{
108	efi_guid_t efi_blkio_guid = EFI_BLOCK_IO_PROTOCOL_GUID;
109	efi_guid_t efi_devpath_guid = EFI_DEVICE_PATH_PROTOCOL_GUID;
110	efi_guid_t efi_pathutil_guid = EFI_DEVICE_PATH_UTILITIES_PROTOCOL_GUID;
111	efi_guid_t efi_pathtext_guid = EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
112	struct efi_boot_services *boot = efi_get_boot();
113	struct efi_device_path_utilities_protocol *util;
114	struct efi_device_path_to_text_protocol *text;
115	struct efi_device_path *path;
116	struct efi_block_io *blkio;
117	efi_uintn_t num_handles;
118	efi_handle_t *handle;
119	int ret, i;
120
121	if (!boot)
122		return log_msg_ret("sys", -ENOSYS);
123
124	/* Find all devices which support the block I/O protocol */
125	ret = boot->locate_handle_buffer(BY_PROTOCOL, &efi_blkio_guid, NULL,
126				  &num_handles, &handle);
127	if (ret)
128		return log_msg_ret("loc", -ENOTSUPP);
129	log_debug("Found %d handles:\n", (int)num_handles);
130
131	/* We need to look up the path size and convert it to text */
132	ret = boot->locate_protocol(&efi_pathutil_guid, NULL, (void **)&util);
133	if (ret)
134		return log_msg_ret("util", -ENOTSUPP);
135	ret = boot->locate_protocol(&efi_pathtext_guid, NULL, (void **)&text);
136	if (ret)
137		return log_msg_ret("text", -ENOTSUPP);
138
139	for (i = 0; i < num_handles; i++) {
140		struct udevice *dev;
141		const u16 *name;
142		bool is_part;
143		int len;
144
145		ret = boot->handle_protocol(handle[i], &efi_devpath_guid,
146					    (void **)&path);
147		if (ret) {
148			log_warning("- devpath %d failed (ret=%d)\n", i, ret);
149			continue;
150		}
151
152		ret = boot->handle_protocol(handle[i], &efi_blkio_guid,
153					    (void **)&blkio);
154		if (ret) {
155			log_warning("- blkio %d failed (ret=%d)\n", i, ret);
156			continue;
157		}
158
159		name = text->convert_device_path_to_text(path, true, false);
160		is_part = devpath_is_partition(path);
161
162		if (!is_part) {
163			len = util->get_device_path_size(path);
164			ret = efi_bind_block(handle[i], blkio, path, len, &dev);
165			if (ret) {
166				log_warning("- blkio bind %d failed (ret=%d)\n",
167					    i, ret);
168				continue;
169			}
170		} else {
171			dev = NULL;
172		}
173
174		/*
175		 * Show the device name if we created one. Otherwise indicate
176		 * that it is a partition.
177		 */
178		printf("%2d: %-12s %ls\n", i, dev ? dev->name : "<partition>",
179		       name);
180	}
181	boot->free_pool(handle);
182
183	return 0;
184}
185
186/**
187 * board_early_init_r() - Scan for UEFI devices that should be available
188 *
189 * This sets up block devices within U-Boot for those found in UEFI. With this,
190 * U-Boot can access those devices
191 *
192 * Returns: 0 on success, -ve on error
193 */
194int board_early_init_r(void)
195{
196	if (gd->flags & GD_FLG_RELOC) {
197		int ret;
198
199		ret = setup_block();
200		if (ret)
201			return ret;
202	}
203
204	return 0;
205}
206