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![Greg Kroah-Hartman](/assets/img/avatar_default.png)
Commitc93bd17541
("powerpc/fsl: move to use bus_get_dev_root()") changed to use bus_get_dev_root() but didn't consider that the function can fail and return an uninitialized value of ret (hint, the function can never fail, but the compiler doesn't know that.) Fix this up by setting ret to -EINVAL just in case something really goes wrong with the call to bus_get_dev_root(). Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: linuxppc-dev@lists.ozlabs.org Fixes:c93bd17541
("powerpc/fsl: move to use bus_get_dev_root()") Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202303280045.4oaaezcn-lkp@intel.com/ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20230327181606.1424846-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
167 lines
3.4 KiB
C
167 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* MPIC timer wakeup driver
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*
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* Copyright 2013 Freescale Semiconductor, Inc.
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/device.h>
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#include <asm/mpic_timer.h>
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#include <asm/mpic.h>
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struct fsl_mpic_timer_wakeup {
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struct mpic_timer *timer;
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struct work_struct free_work;
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};
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static struct fsl_mpic_timer_wakeup *fsl_wakeup;
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static DEFINE_MUTEX(sysfs_lock);
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static void fsl_free_resource(struct work_struct *ws)
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{
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struct fsl_mpic_timer_wakeup *wakeup =
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container_of(ws, struct fsl_mpic_timer_wakeup, free_work);
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mutex_lock(&sysfs_lock);
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if (wakeup->timer) {
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disable_irq_wake(wakeup->timer->irq);
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mpic_free_timer(wakeup->timer);
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}
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wakeup->timer = NULL;
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mutex_unlock(&sysfs_lock);
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}
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static irqreturn_t fsl_mpic_timer_irq(int irq, void *dev_id)
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{
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struct fsl_mpic_timer_wakeup *wakeup = dev_id;
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schedule_work(&wakeup->free_work);
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return wakeup->timer ? IRQ_HANDLED : IRQ_NONE;
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}
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static ssize_t fsl_timer_wakeup_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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time64_t interval = 0;
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mutex_lock(&sysfs_lock);
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if (fsl_wakeup->timer) {
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mpic_get_remain_time(fsl_wakeup->timer, &interval);
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interval++;
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}
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mutex_unlock(&sysfs_lock);
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return sprintf(buf, "%lld\n", interval);
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}
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static ssize_t fsl_timer_wakeup_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t count)
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{
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time64_t interval;
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int ret;
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if (kstrtoll(buf, 0, &interval))
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return -EINVAL;
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mutex_lock(&sysfs_lock);
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if (fsl_wakeup->timer) {
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disable_irq_wake(fsl_wakeup->timer->irq);
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mpic_free_timer(fsl_wakeup->timer);
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fsl_wakeup->timer = NULL;
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}
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if (!interval) {
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mutex_unlock(&sysfs_lock);
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return count;
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}
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fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
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fsl_wakeup, interval);
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if (!fsl_wakeup->timer) {
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mutex_unlock(&sysfs_lock);
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return -EINVAL;
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}
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ret = enable_irq_wake(fsl_wakeup->timer->irq);
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if (ret) {
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mpic_free_timer(fsl_wakeup->timer);
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fsl_wakeup->timer = NULL;
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mutex_unlock(&sysfs_lock);
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return ret;
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}
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mpic_start_timer(fsl_wakeup->timer);
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mutex_unlock(&sysfs_lock);
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return count;
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}
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static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644,
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fsl_timer_wakeup_show, fsl_timer_wakeup_store);
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static int __init fsl_wakeup_sys_init(void)
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{
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struct device *dev_root;
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int ret = -EINVAL;
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fsl_wakeup = kzalloc(sizeof(struct fsl_mpic_timer_wakeup), GFP_KERNEL);
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if (!fsl_wakeup)
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return -ENOMEM;
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INIT_WORK(&fsl_wakeup->free_work, fsl_free_resource);
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dev_root = bus_get_dev_root(&mpic_subsys);
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if (dev_root) {
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ret = device_create_file(dev_root, &mpic_attributes);
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put_device(dev_root);
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if (ret)
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kfree(fsl_wakeup);
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}
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return ret;
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}
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static void __exit fsl_wakeup_sys_exit(void)
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{
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struct device *dev_root;
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dev_root = bus_get_dev_root(&mpic_subsys);
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if (dev_root) {
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device_remove_file(dev_root, &mpic_attributes);
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put_device(dev_root);
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}
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mutex_lock(&sysfs_lock);
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if (fsl_wakeup->timer) {
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disable_irq_wake(fsl_wakeup->timer->irq);
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mpic_free_timer(fsl_wakeup->timer);
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}
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kfree(fsl_wakeup);
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mutex_unlock(&sysfs_lock);
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}
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module_init(fsl_wakeup_sys_init);
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module_exit(fsl_wakeup_sys_exit);
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MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver");
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>");
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