c942fddf87
Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
131 lines
2.5 KiB
C
131 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
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*/
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#include <linux/spinlock.h>
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#include <linux/list.h>
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#include <linux/sched/signal.h>
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#include <linux/delay.h>
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#include <linux/export.h>
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#include "w1_internal.h"
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DEFINE_SPINLOCK(w1_flock);
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static LIST_HEAD(w1_families);
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/**
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* w1_register_family() - register a device family driver
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* @newf: family to register
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*/
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int w1_register_family(struct w1_family *newf)
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{
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struct list_head *ent, *n;
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struct w1_family *f;
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int ret = 0;
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spin_lock(&w1_flock);
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list_for_each_safe(ent, n, &w1_families) {
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f = list_entry(ent, struct w1_family, family_entry);
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if (f->fid == newf->fid) {
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ret = -EEXIST;
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break;
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}
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}
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if (!ret) {
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atomic_set(&newf->refcnt, 0);
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list_add_tail(&newf->family_entry, &w1_families);
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}
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spin_unlock(&w1_flock);
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/* check default devices against the new set of drivers */
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w1_reconnect_slaves(newf, 1);
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return ret;
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}
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EXPORT_SYMBOL(w1_register_family);
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/**
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* w1_unregister_family() - unregister a device family driver
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* @fent: family to unregister
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*/
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void w1_unregister_family(struct w1_family *fent)
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{
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struct list_head *ent, *n;
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struct w1_family *f;
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spin_lock(&w1_flock);
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list_for_each_safe(ent, n, &w1_families) {
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f = list_entry(ent, struct w1_family, family_entry);
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if (f->fid == fent->fid) {
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list_del(&fent->family_entry);
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break;
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}
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}
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spin_unlock(&w1_flock);
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/* deatch devices using this family code */
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w1_reconnect_slaves(fent, 0);
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while (atomic_read(&fent->refcnt)) {
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pr_info("Waiting for family %u to become free: refcnt=%d.\n",
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fent->fid, atomic_read(&fent->refcnt));
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if (msleep_interruptible(1000))
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flush_signals(current);
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}
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}
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EXPORT_SYMBOL(w1_unregister_family);
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/*
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* Should be called under w1_flock held.
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*/
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struct w1_family * w1_family_registered(u8 fid)
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{
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struct list_head *ent, *n;
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struct w1_family *f = NULL;
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int ret = 0;
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list_for_each_safe(ent, n, &w1_families) {
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f = list_entry(ent, struct w1_family, family_entry);
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if (f->fid == fid) {
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ret = 1;
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break;
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}
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}
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return (ret) ? f : NULL;
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}
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static void __w1_family_put(struct w1_family *f)
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{
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atomic_dec(&f->refcnt);
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}
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void w1_family_put(struct w1_family *f)
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{
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spin_lock(&w1_flock);
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__w1_family_put(f);
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spin_unlock(&w1_flock);
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}
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#if 0
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void w1_family_get(struct w1_family *f)
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{
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spin_lock(&w1_flock);
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__w1_family_get(f);
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spin_unlock(&w1_flock);
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}
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#endif /* 0 */
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void __w1_family_get(struct w1_family *f)
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{
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smp_mb__before_atomic();
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atomic_inc(&f->refcnt);
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smp_mb__after_atomic();
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}
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