Revision 3f0116c3238a96bc18ad4b4acefe4e7be32fa861 authored by Ingo Molnar on 10 October 2013, 08:16:30 UTC, committed by Ingo Molnar on 11 October 2013, 05:39:14 UTC
Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto' constructs, as outlined here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Implement a workaround suggested by Jakub Jelinek. Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Suggested-by: Jakub Jelinek <jakub@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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rtc-pcf50633.c
/* NXP PCF50633 RTC Driver
*
* (C) 2006-2008 by Openmoko, Inc.
* Author: Balaji Rao <balajirrao@openmoko.org>
* All rights reserved.
*
* Broken down from monstrous PCF50633 driver mainly by
* Harald Welte, Andy Green and Werner Almesberger
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/err.h>
#include <linux/mfd/pcf50633/core.h>
#define PCF50633_REG_RTCSC 0x59 /* Second */
#define PCF50633_REG_RTCMN 0x5a /* Minute */
#define PCF50633_REG_RTCHR 0x5b /* Hour */
#define PCF50633_REG_RTCWD 0x5c /* Weekday */
#define PCF50633_REG_RTCDT 0x5d /* Day */
#define PCF50633_REG_RTCMT 0x5e /* Month */
#define PCF50633_REG_RTCYR 0x5f /* Year */
#define PCF50633_REG_RTCSCA 0x60 /* Alarm Second */
#define PCF50633_REG_RTCMNA 0x61 /* Alarm Minute */
#define PCF50633_REG_RTCHRA 0x62 /* Alarm Hour */
#define PCF50633_REG_RTCWDA 0x63 /* Alarm Weekday */
#define PCF50633_REG_RTCDTA 0x64 /* Alarm Day */
#define PCF50633_REG_RTCMTA 0x65 /* Alarm Month */
#define PCF50633_REG_RTCYRA 0x66 /* Alarm Year */
enum pcf50633_time_indexes {
PCF50633_TI_SEC,
PCF50633_TI_MIN,
PCF50633_TI_HOUR,
PCF50633_TI_WKDAY,
PCF50633_TI_DAY,
PCF50633_TI_MONTH,
PCF50633_TI_YEAR,
PCF50633_TI_EXTENT /* always last */
};
struct pcf50633_time {
u_int8_t time[PCF50633_TI_EXTENT];
};
struct pcf50633_rtc {
int alarm_enabled;
int alarm_pending;
struct pcf50633 *pcf;
struct rtc_device *rtc_dev;
};
static void pcf2rtc_time(struct rtc_time *rtc, struct pcf50633_time *pcf)
{
rtc->tm_sec = bcd2bin(pcf->time[PCF50633_TI_SEC]);
rtc->tm_min = bcd2bin(pcf->time[PCF50633_TI_MIN]);
rtc->tm_hour = bcd2bin(pcf->time[PCF50633_TI_HOUR]);
rtc->tm_wday = bcd2bin(pcf->time[PCF50633_TI_WKDAY]);
rtc->tm_mday = bcd2bin(pcf->time[PCF50633_TI_DAY]);
rtc->tm_mon = bcd2bin(pcf->time[PCF50633_TI_MONTH]) - 1;
rtc->tm_year = bcd2bin(pcf->time[PCF50633_TI_YEAR]) + 100;
}
static void rtc2pcf_time(struct pcf50633_time *pcf, struct rtc_time *rtc)
{
pcf->time[PCF50633_TI_SEC] = bin2bcd(rtc->tm_sec);
pcf->time[PCF50633_TI_MIN] = bin2bcd(rtc->tm_min);
pcf->time[PCF50633_TI_HOUR] = bin2bcd(rtc->tm_hour);
pcf->time[PCF50633_TI_WKDAY] = bin2bcd(rtc->tm_wday);
pcf->time[PCF50633_TI_DAY] = bin2bcd(rtc->tm_mday);
pcf->time[PCF50633_TI_MONTH] = bin2bcd(rtc->tm_mon + 1);
pcf->time[PCF50633_TI_YEAR] = bin2bcd(rtc->tm_year % 100);
}
static int
pcf50633_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct pcf50633_rtc *rtc = dev_get_drvdata(dev);
int err;
if (enabled)
err = pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
else
err = pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
if (err < 0)
return err;
rtc->alarm_enabled = enabled;
return 0;
}
static int pcf50633_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct pcf50633_rtc *rtc;
struct pcf50633_time pcf_tm;
int ret;
rtc = dev_get_drvdata(dev);
ret = pcf50633_read_block(rtc->pcf, PCF50633_REG_RTCSC,
PCF50633_TI_EXTENT,
&pcf_tm.time[0]);
if (ret != PCF50633_TI_EXTENT) {
dev_err(dev, "Failed to read time\n");
return -EIO;
}
dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
pcf_tm.time[PCF50633_TI_DAY],
pcf_tm.time[PCF50633_TI_MONTH],
pcf_tm.time[PCF50633_TI_YEAR],
pcf_tm.time[PCF50633_TI_HOUR],
pcf_tm.time[PCF50633_TI_MIN],
pcf_tm.time[PCF50633_TI_SEC]);
pcf2rtc_time(tm, &pcf_tm);
dev_dbg(dev, "RTC_TIME: %u.%u.%u %u:%u:%u\n",
tm->tm_mday, tm->tm_mon, tm->tm_year,
tm->tm_hour, tm->tm_min, tm->tm_sec);
return rtc_valid_tm(tm);
}
static int pcf50633_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct pcf50633_rtc *rtc;
struct pcf50633_time pcf_tm;
int alarm_masked, ret = 0;
rtc = dev_get_drvdata(dev);
dev_dbg(dev, "RTC_TIME: %u.%u.%u %u:%u:%u\n",
tm->tm_mday, tm->tm_mon, tm->tm_year,
tm->tm_hour, tm->tm_min, tm->tm_sec);
rtc2pcf_time(&pcf_tm, tm);
dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
pcf_tm.time[PCF50633_TI_DAY],
pcf_tm.time[PCF50633_TI_MONTH],
pcf_tm.time[PCF50633_TI_YEAR],
pcf_tm.time[PCF50633_TI_HOUR],
pcf_tm.time[PCF50633_TI_MIN],
pcf_tm.time[PCF50633_TI_SEC]);
alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
if (!alarm_masked)
pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
/* Returns 0 on success */
ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSC,
PCF50633_TI_EXTENT,
&pcf_tm.time[0]);
if (!alarm_masked)
pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
return ret;
}
static int pcf50633_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pcf50633_rtc *rtc;
struct pcf50633_time pcf_tm;
int ret = 0;
rtc = dev_get_drvdata(dev);
alrm->enabled = rtc->alarm_enabled;
alrm->pending = rtc->alarm_pending;
ret = pcf50633_read_block(rtc->pcf, PCF50633_REG_RTCSCA,
PCF50633_TI_EXTENT, &pcf_tm.time[0]);
if (ret != PCF50633_TI_EXTENT) {
dev_err(dev, "Failed to read time\n");
return -EIO;
}
pcf2rtc_time(&alrm->time, &pcf_tm);
return rtc_valid_tm(&alrm->time);
}
static int pcf50633_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pcf50633_rtc *rtc;
struct pcf50633_time pcf_tm;
int alarm_masked, ret = 0;
rtc = dev_get_drvdata(dev);
rtc2pcf_time(&pcf_tm, &alrm->time);
/* do like mktime does and ignore tm_wday */
pcf_tm.time[PCF50633_TI_WKDAY] = 7;
alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
/* disable alarm interrupt */
if (!alarm_masked)
pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
/* Returns 0 on success */
ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSCA,
PCF50633_TI_EXTENT, &pcf_tm.time[0]);
if (!alrm->enabled)
rtc->alarm_pending = 0;
if (!alarm_masked || alrm->enabled)
pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
rtc->alarm_enabled = alrm->enabled;
return ret;
}
static struct rtc_class_ops pcf50633_rtc_ops = {
.read_time = pcf50633_rtc_read_time,
.set_time = pcf50633_rtc_set_time,
.read_alarm = pcf50633_rtc_read_alarm,
.set_alarm = pcf50633_rtc_set_alarm,
.alarm_irq_enable = pcf50633_rtc_alarm_irq_enable,
};
static void pcf50633_rtc_irq(int irq, void *data)
{
struct pcf50633_rtc *rtc = data;
rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
rtc->alarm_pending = 1;
}
static int pcf50633_rtc_probe(struct platform_device *pdev)
{
struct pcf50633_rtc *rtc;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->pcf = dev_to_pcf50633(pdev->dev.parent);
platform_set_drvdata(pdev, rtc);
rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "pcf50633-rtc",
&pcf50633_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc_dev))
return PTR_ERR(rtc->rtc_dev);
pcf50633_register_irq(rtc->pcf, PCF50633_IRQ_ALARM,
pcf50633_rtc_irq, rtc);
return 0;
}
static int pcf50633_rtc_remove(struct platform_device *pdev)
{
struct pcf50633_rtc *rtc;
rtc = platform_get_drvdata(pdev);
pcf50633_free_irq(rtc->pcf, PCF50633_IRQ_ALARM);
return 0;
}
static struct platform_driver pcf50633_rtc_driver = {
.driver = {
.name = "pcf50633-rtc",
},
.probe = pcf50633_rtc_probe,
.remove = pcf50633_rtc_remove,
};
module_platform_driver(pcf50633_rtc_driver);
MODULE_DESCRIPTION("PCF50633 RTC driver");
MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
MODULE_LICENSE("GPL");
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