xref: /freebsd/sys/compat/linuxkpi/common/src/linux_firmware.c (revision 6be3386466ab79a84b48429ae66244f21526d3df)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2020-2021 The FreeBSD Foundation
5  *
6  * This software was developed by Björn Zeeb under sponsorship from
7  * the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #include <sys/types.h>
34 #include <sys/malloc.h>
35 #include <sys/firmware.h>
36 
37 #include <linux/types.h>
38 #include <linux/device.h>
39 
40 #include <linux/firmware.h>
41 #undef firmware
42 
43 MALLOC_DEFINE(M_LKPI_FW, "lkpifw", "LinuxKPI firmware");
44 
45 static int
46 _linuxkpi_request_firmware(const char *fw_name, const struct linuxkpi_firmware **fw,
47     struct device *dev, gfp_t gfp __unused, bool enoentok, bool warn)
48 {
49 	const struct firmware *fbdfw;
50 	struct linuxkpi_firmware *lfw;
51 	const char *fwimg;
52 	char *p;
53 	uint32_t flags;
54 
55 	if (fw_name == NULL || fw == NULL || dev == NULL)
56 		return (-EINVAL);
57 
58 	/* Set independent on "warn". To debug, bootverbose is avail. */
59 	flags = FIRMWARE_GET_NOWARN;
60 
61 	KASSERT(gfp == GFP_KERNEL, ("%s: gfp %#x\n", __func__, gfp));
62 	lfw = malloc(sizeof(*lfw), M_LKPI_FW, M_WAITOK | M_ZERO);
63 
64 	/*
65 	 * Linux can have a path in the firmware which is hard to replicate
66 	 * for auto-firmware-module-loading.
67 	 * On FreeBSD, depending on what people do, the firmware will either
68 	 * be called "fw", or "dir_fw", or "modname_dir_fw".  The latter the
69 	 * driver author has to deal with herself (requesting the special name).
70 	 * We also optionally flatten '/'s and '.'s as some firmware modules do.
71 	 * We probe in the least-of-work order avoiding memory operations.
72 	 * It will be preferred to build the firmware .ko in a well matching
73 	 * way rather than adding more name-mangling-hacks here in the future
74 	 * (though we could if needed).
75 	 */
76 	/* (1) Try any name removed of path. */
77 	fwimg = strrchr(fw_name, '/');
78 	if (fwimg != NULL)
79 		fwimg++;
80 	if (fwimg == NULL || *fwimg == '\0')
81 		fwimg = fw_name;
82 	fbdfw = firmware_get_flags(fwimg, flags);
83 	/* (2) Try the original name if we have not yet. */
84 	if (fbdfw == NULL && fwimg != fw_name) {
85 		fwimg = fw_name;
86 		fbdfw = firmware_get_flags(fwimg, flags);
87 	}
88 	/* (3) Flatten '/' and then '.' to '_' and try with adjusted name. */
89 	if (fbdfw == NULL &&
90 	    (strchr(fw_name, '/') != NULL || strchr(fw_name, '.') != NULL)) {
91 		fwimg = strdup(fw_name, M_LKPI_FW);
92 		if (fwimg != NULL) {
93 			while ((p = strchr(fwimg, '/')) != NULL)
94 				*p = '_';
95 			fbdfw = firmware_get_flags(fwimg, flags);
96 			if (fbdfw == NULL) {
97 				while ((p = strchr(fwimg, '.')) != NULL)
98 					*p = '_';
99 				fbdfw = firmware_get_flags(fwimg, flags);
100 			}
101 			free(__DECONST(void *, fwimg), M_LKPI_FW);
102 		}
103 	}
104 	if (fbdfw == NULL) {
105 		if (enoentok)
106 			*fw = lfw;
107 		else {
108 			free(lfw, M_LKPI_FW);
109 			*fw = NULL;
110 		}
111 		if (warn)
112 			device_printf(dev->bsddev, "could not load firmware "
113 			    "image '%s'\n", fw_name);
114 		return (-ENOENT);
115 	}
116 
117 	device_printf(dev->bsddev,"successfully loaded firmware image '%s'\n",
118 	    fw_name);
119 	lfw->fbdfw = fbdfw;
120 	lfw->data = (const uint8_t *)fbdfw->data;
121 	lfw->size = fbdfw->datasize;
122 	*fw = lfw;
123 	return (0);
124 }
125 
126 int
127 linuxkpi_request_firmware_nowait(struct module *mod __unused, bool _t __unused,
128     const char *fw_name, struct device *dev, gfp_t gfp, void *drv,
129     void(*cont)(const struct linuxkpi_firmware *, void *))
130 {
131 	const struct linuxkpi_firmware *lfw;
132 	int error;
133 
134 	/*
135 	 * Linux seems to run the callback if it cannot find the firmware.
136 	 * The fact that this is "_nowait()" and has a callback seems to
137 	 * imply that this is run in a deferred conext which we currently
138 	 * do not do.  Should it become necessary (a driver actually requiring
139 	 * it) we would need to implement it here.
140 	 */
141 	error = _linuxkpi_request_firmware(fw_name, &lfw, dev, gfp, true, true);
142 	if (error == -ENOENT)
143 		error = 0;
144 	if (error == 0)
145 		cont(lfw, drv);
146 
147 	return (error);
148 }
149 
150 int
151 linuxkpi_request_firmware(const struct linuxkpi_firmware **fw,
152     const char *fw_name, struct device *dev)
153 {
154 
155 	return (_linuxkpi_request_firmware(fw_name, fw, dev, GFP_KERNEL, false,
156 	    true));
157 }
158 
159 int
160 linuxkpi_firmware_request_nowarn(const struct linuxkpi_firmware **fw,
161     const char *fw_name, struct device *dev)
162 {
163 
164 	return (_linuxkpi_request_firmware(fw_name, fw, dev, GFP_KERNEL, false,
165 	    false));
166 }
167 
168 void
169 linuxkpi_release_firmware(const struct linuxkpi_firmware *fw)
170 {
171 
172 	if (fw == NULL)
173 		return;
174 
175 	if (fw->fbdfw)
176 		firmware_put(fw->fbdfw, FIRMWARE_UNLOAD);
177 	free(__DECONST(void *, fw), M_LKPI_FW);
178 }
179