1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2020-2021 The FreeBSD Foundation
5  * Copyright (c) 2022 Bjoern A. Zeeb
6  *
7  * This software was developed by Björn Zeeb under sponsorship from
8  * the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/types.h>
35 #include <sys/malloc.h>
36 #include <sys/firmware.h>
37 #include <sys/queue.h>
38 #include <sys/taskqueue.h>
39 
40 #include <linux/types.h>
41 #include <linux/device.h>
42 
43 #include <linux/firmware.h>
44 #undef firmware
45 
46 MALLOC_DEFINE(M_LKPI_FW, "lkpifw", "LinuxKPI firmware");
47 
48 struct lkpi_fw_task {
49 	/* Task and arguments for the "nowait" callback. */
50 	struct task		fw_task;
51 	gfp_t			gfp;
52 	const char		*fw_name;
53 	struct device		*dev;
54 	void			*drv;
55 	void(*cont)(const struct linuxkpi_firmware *, void *);
56 };
57 
58 static int
59 _linuxkpi_request_firmware(const char *fw_name, const struct linuxkpi_firmware **fw,
60     struct device *dev, gfp_t gfp __unused, bool enoentok, bool warn)
61 {
62 	const struct firmware *fbdfw;
63 	struct linuxkpi_firmware *lfw;
64 	const char *fwimg;
65 	char *p;
66 	uint32_t flags;
67 
68 	if (fw_name == NULL || fw == NULL || dev == NULL) {
69 		*fw = NULL;
70 		return (-EINVAL);
71 	}
72 
73 	/* Set independent on "warn". To debug, bootverbose is avail. */
74 	flags = FIRMWARE_GET_NOWARN;
75 
76 	KASSERT(gfp == GFP_KERNEL, ("%s: gfp %#x\n", __func__, gfp));
77 	lfw = malloc(sizeof(*lfw), M_LKPI_FW, M_WAITOK | M_ZERO);
78 
79 	/*
80 	 * Linux can have a path in the firmware which is hard to replicate
81 	 * for auto-firmware-module-loading.
82 	 * On FreeBSD, depending on what people do, the firmware will either
83 	 * be called "fw", or "dir_fw", or "modname_dir_fw".  The latter the
84 	 * driver author has to deal with herself (requesting the special name).
85 	 * We also optionally flatten '/'s and '.'s as some firmware modules do.
86 	 * We probe in the least-of-work order avoiding memory operations.
87 	 * It will be preferred to build the firmware .ko in a well matching
88 	 * way rather than adding more name-mangling-hacks here in the future
89 	 * (though we could if needed).
90 	 */
91 	/* (1) Try any name removed of path. */
92 	fwimg = strrchr(fw_name, '/');
93 	if (fwimg != NULL)
94 		fwimg++;
95 	if (fwimg == NULL || *fwimg == '\0')
96 		fwimg = fw_name;
97 	fbdfw = firmware_get_flags(fwimg, flags);
98 	/* (2) Try the original name if we have not yet. */
99 	if (fbdfw == NULL && fwimg != fw_name) {
100 		fwimg = fw_name;
101 		fbdfw = firmware_get_flags(fwimg, flags);
102 	}
103 	/* (3) Flatten '/', '.' and '-' to '_' and try with adjusted name. */
104 	if (fbdfw == NULL &&
105 	    (strchr(fw_name, '/') != NULL || strchr(fw_name, '.') != NULL ||
106 	    strchr(fw_name, '-'))) {
107 		fwimg = strdup(fw_name, M_LKPI_FW);
108 		if (fwimg != NULL) {
109 			while ((p = strchr(fwimg, '/')) != NULL)
110 				*p = '_';
111 			fbdfw = firmware_get_flags(fwimg, flags);
112 			if (fbdfw == NULL) {
113 				while ((p = strchr(fwimg, '.')) != NULL)
114 					*p = '_';
115 				fbdfw = firmware_get_flags(fwimg, flags);
116 			}
117 			if (fbdfw == NULL) {
118 				while ((p = strchr(fwimg, '-')) != NULL)
119 					*p = '_';
120 				fbdfw = firmware_get_flags(fwimg, flags);
121 			}
122 			free(__DECONST(void *, fwimg), M_LKPI_FW);
123 		}
124 	}
125 	if (fbdfw == NULL) {
126 		if (enoentok)
127 			*fw = lfw;
128 		else {
129 			free(lfw, M_LKPI_FW);
130 			*fw = NULL;
131 		}
132 		if (warn)
133 			device_printf(dev->bsddev, "could not load firmware "
134 			    "image '%s'\n", fw_name);
135 		return (-ENOENT);
136 	}
137 
138 	device_printf(dev->bsddev,"successfully loaded firmware image '%s'\n",
139 	    fw_name);
140 	lfw->fbdfw = fbdfw;
141 	lfw->data = (const uint8_t *)fbdfw->data;
142 	lfw->size = fbdfw->datasize;
143 	*fw = lfw;
144 	return (0);
145 }
146 
147 static void
148 lkpi_fw_task(void *ctx, int pending)
149 {
150 	struct lkpi_fw_task *lfwt;
151 	const struct linuxkpi_firmware *fw;
152 
153 	KASSERT(ctx != NULL && pending == 1, ("%s: lfwt %p, pending %d\n",
154 	    __func__, ctx, pending));
155 
156 	lfwt = ctx;
157 	if (lfwt->cont == NULL)
158 		goto out;
159 
160 	_linuxkpi_request_firmware(lfwt->fw_name, &fw, lfwt->dev,
161 	    lfwt->gfp, true, true);
162 
163 	/*
164 	 * Linux seems to run the callback if it cannot find the firmware.
165 	 * We call it in all cases as it is the only feedback to the requester.
166 	 */
167 	lfwt->cont(fw, lfwt->drv);
168 	/* Do not assume fw is still valid! */
169 
170 out:
171 	free(lfwt, M_LKPI_FW);
172 }
173 
174 int
175 linuxkpi_request_firmware_nowait(struct module *mod __unused, bool _t __unused,
176     const char *fw_name, struct device *dev, gfp_t gfp, void *drv,
177     void(*cont)(const struct linuxkpi_firmware *, void *))
178 {
179 	struct lkpi_fw_task *lfwt;
180 	int error;
181 
182 	lfwt = malloc(sizeof(*lfwt), M_LKPI_FW, M_WAITOK | M_ZERO);
183 	lfwt->gfp = gfp;
184 	lfwt->fw_name = fw_name;
185 	lfwt->dev = dev;
186 	lfwt->drv = drv;
187 	lfwt->cont = cont;
188 	TASK_INIT(&lfwt->fw_task, 0, lkpi_fw_task, lfwt);
189 	error = taskqueue_enqueue(taskqueue_thread, &lfwt->fw_task);
190 
191 	if (error)
192 		return (-error);
193 	return (0);
194 }
195 
196 int
197 linuxkpi_request_firmware(const struct linuxkpi_firmware **fw,
198     const char *fw_name, struct device *dev)
199 {
200 
201 	return (_linuxkpi_request_firmware(fw_name, fw, dev, GFP_KERNEL, false,
202 	    true));
203 }
204 
205 int
206 linuxkpi_firmware_request_nowarn(const struct linuxkpi_firmware **fw,
207     const char *fw_name, struct device *dev)
208 {
209 
210 	return (_linuxkpi_request_firmware(fw_name, fw, dev, GFP_KERNEL, false,
211 	    false));
212 }
213 
214 void
215 linuxkpi_release_firmware(const struct linuxkpi_firmware *fw)
216 {
217 
218 	if (fw == NULL)
219 		return;
220 
221 	if (fw->fbdfw)
222 		firmware_put(fw->fbdfw, FIRMWARE_UNLOAD);
223 	free(__DECONST(void *, fw), M_LKPI_FW);
224 }
225 
226 int
227 linuxkpi_request_partial_firmware_into_buf(const struct linuxkpi_firmware **fw,
228     const char *fw_name, struct device *dev, uint8_t *buf, size_t buflen,
229     size_t offset)
230 {
231 	const struct linuxkpi_firmware *lfw;
232 	int error;
233 
234 	error = linuxkpi_request_firmware(fw, fw_name, dev);
235 	if (error != 0)
236 		return (error);
237 
238 	lfw = *fw;
239 	if ((offset + buflen) >= lfw->size) {
240 		linuxkpi_release_firmware(lfw);
241 		return (-ERANGE);
242 	}
243 
244 	memcpy(buf, lfw->data + offset, buflen);
245 
246 	return (0);
247 }
248