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      1 /*	$NetBSD: linux_firmware.c,v 1.2 2021/12/19 12:01:04 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: linux_firmware.c,v 1.2 2021/12/19 12:01:04 riastradh Exp $");
     34 
     35 #include <sys/types.h>
     36 #include <sys/device.h>
     37 #include <sys/kmem.h>
     38 #include <sys/module.h>
     39 #include <sys/systm.h>
     40 
     41 #include <linux/firmware.h>
     42 #include <linux/slab.h>
     43 #include <linux/string.h>
     44 #include <linux/workqueue.h>
     45 
     46 struct firmload_work {
     47 	char		*flw_name;
     48 	void		(*flw_callback)(const struct firmware *, void *);
     49 	void		*flw_cookie;
     50 	struct device	*flw_device;
     51 	struct module	*flw_module;
     52 	struct work_struct flw_work;
     53 };
     54 
     55 int
     56 request_firmware(const struct firmware **fwp, const char *image_name,
     57     struct device *dev)
     58 {
     59 	const char *drvname;
     60 	struct firmware *fw;
     61 	firmware_handle_t handle;
     62 	int ret;
     63 
     64 	fw = kmem_alloc(sizeof(*fw), KM_SLEEP);
     65 
     66 	/*
     67 	 * If driver xyz(4) asks for xyz/foo/bar.bin, turn that into
     68 	 * just foo/bar.bin.  This leaves open the possibility of name
     69 	 * collisions.  Let's hope upstream is sensible about this.
     70 	 */
     71 	drvname = device_cfdriver(dev)->cd_name;
     72 	if ((strncmp(drvname, image_name, strlen(drvname)) == 0) &&
     73 	    (image_name[strlen(drvname)] == '/'))
     74 		image_name += (strlen(drvname) + 1);
     75 
     76 	/* XXX errno NetBSD->Linux */
     77 	ret = -firmware_open(drvname, image_name, &handle);
     78 	if (ret)
     79 		goto fail0;
     80 	fw->size = firmware_get_size(handle);
     81 	fw->data = firmware_malloc(fw->size);
     82 
     83 	/* XXX errno NetBSD->Linux */
     84 	ret = -firmware_read(handle, 0, fw->data, fw->size);
     85 	(void)firmware_close(handle);
     86 	if (ret)
     87 		goto fail1;
     88 
     89 	/* Success!  */
     90 	*fwp = fw;
     91 	return 0;
     92 
     93 fail1:	firmware_free(fw->data, fw->size);
     94 fail0:	KASSERT(ret);
     95 	kmem_free(fw, sizeof(*fw));
     96 	*fwp = NULL;
     97 	return ret;
     98 }
     99 
    100 int
    101 request_firmware_direct(const struct firmware **fwp, const char *image_name,
    102     struct device *dev)
    103 {
    104 
    105 	return request_firmware(fwp, image_name, dev);
    106 }
    107 
    108 int
    109 firmware_request_nowarn(const struct firmware **fwp, const char *image_name,
    110     struct device *dev)
    111 {
    112 
    113 	return request_firmware(fwp, image_name, dev);
    114 }
    115 
    116 static void
    117 request_firmware_work(struct work_struct *wk)
    118 {
    119 	struct firmload_work *work = container_of(wk, struct firmload_work,
    120 	    flw_work);
    121 	const struct firmware *fw;
    122 	int ret;
    123 
    124 	/* Reqeust the firmware.  If it failed, set it to NULL.  */
    125 	ret = request_firmware(&fw, work->flw_name, work->flw_device);
    126 	if (ret)
    127 		fw = NULL;
    128 
    129 	/* Call the callback. */
    130 	(*work->flw_callback)(fw, work->flw_cookie);
    131 
    132 	/*
    133 	 * Release the device and module references now that we're
    134 	 * done.
    135 	 *
    136 	 * XXX Heh. What if the module gets unloaded _during_
    137 	 * module_rele because it went to zero?
    138 	 */
    139 	/* XXX device_release */
    140 	if (work->flw_module)
    141 		module_rele(work->flw_module);
    142 }
    143 
    144 int
    145 request_firmware_nowait(struct module *module, bool uevent, const char *name,
    146     struct device *device, gfp_t gfp, void *cookie,
    147     void (*callback)(const struct firmware *, void *))
    148 {
    149 	char *namedup;
    150 	struct firmload_work *work;
    151 
    152 	/* Allocate memory for it, or fail if we can't.  */
    153 	work = kzalloc(sizeof(*work), gfp);
    154 	if (work == NULL)
    155 		goto fail0;
    156 
    157 	/* Copy the name just in case.  */
    158 	namedup = kstrdup(name, gfp);
    159 	if (namedup == NULL)
    160 		goto fail1;
    161 
    162 	/* Hold the module and device so they don't go away before callback. */
    163 	if (module)
    164 		module_hold(module);
    165 	/* XXX device_acquire(device) */
    166 
    167 	/* Initialize the work.  */
    168 	work->flw_name = namedup;
    169 	work->flw_callback = callback;
    170 	work->flw_cookie = cookie;
    171 	work->flw_device = device;
    172 	work->flw_module = module;
    173 	INIT_WORK(&work->flw_work, request_firmware_work);
    174 
    175 	/* Kick it off.  */
    176 	schedule_work(&work->flw_work);
    177 
    178 	/* Success!  */
    179 	return 0;
    180 
    181 fail1:	kfree(work);
    182 fail0:	return -ENOMEM;
    183 }
    184 
    185 void
    186 release_firmware(const struct firmware *fw)
    187 {
    188 
    189 	if (fw != NULL) {
    190 		firmware_free(fw->data, fw->size);
    191 		kmem_free(__UNCONST(fw), sizeof(*fw));
    192 	}
    193 }
    194