From 47997d756aa2a84ab577e1b0383cc12d582fc69c Mon Sep 17 00:00:00 2001
From: Matt Fleming <matt.fleming@intel.com>
Date: Wed, 21 Sep 2011 16:08:03 +0200
Subject: x86/rtc: Don't recursively acquire rtc_lock

A deadlock was introduced on x86 in commit ef68c8f87ed1 ("x86:
Serialize EFI time accesses on rtc_lock") because efi_get_time()
and friends can be called with rtc_lock already held by
read_persistent_time(), e.g.:

 timekeeping_init()
    read_persistent_clock()     <-- acquire rtc_lock
        efi_get_time()
            phys_efi_get_time() <-- acquire rtc_lock <DEADLOCK>

To fix this let's push the locking down into the get_wallclock()
and set_wallclock() implementations.  Only the clock
implementations that access the x86 RTC directly need to acquire
rtc_lock, so it makes sense to push the locking down into the
rtc, vrtc and efi code.

The virtualization implementations don't require rtc_lock to be
held because they provide their own serialization.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Avi Kivity <avi@redhat.com> [for the virtualization aspect]
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/platform/mrst/vrtc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'arch/x86/platform/mrst/vrtc.c')

diff --git a/arch/x86/platform/mrst/vrtc.c b/arch/x86/platform/mrst/vrtc.c
index 73d70d65e76e..6d5dbcdd444a 100644
--- a/arch/x86/platform/mrst/vrtc.c
+++ b/arch/x86/platform/mrst/vrtc.c
@@ -58,8 +58,11 @@ EXPORT_SYMBOL_GPL(vrtc_cmos_write);
 unsigned long vrtc_get_time(void)
 {
 	u8 sec, min, hour, mday, mon;
+	unsigned long flags;
 	u32 year;
 
+	spin_lock_irqsave(&rtc_lock, flags);
+
 	while ((vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP))
 		cpu_relax();
 
@@ -70,6 +73,8 @@ unsigned long vrtc_get_time(void)
 	mon = vrtc_cmos_read(RTC_MONTH);
 	year = vrtc_cmos_read(RTC_YEAR);
 
+	spin_unlock_irqrestore(&rtc_lock, flags);
+
 	/* vRTC YEAR reg contains the offset to 1960 */
 	year += 1960;
 
@@ -83,8 +88,10 @@ unsigned long vrtc_get_time(void)
 int vrtc_set_mmss(unsigned long nowtime)
 {
 	int real_sec, real_min;
+	unsigned long flags;
 	int vrtc_min;
 
+	spin_lock_irqsave(&rtc_lock, flags);
 	vrtc_min = vrtc_cmos_read(RTC_MINUTES);
 
 	real_sec = nowtime % 60;
@@ -95,6 +102,8 @@ int vrtc_set_mmss(unsigned long nowtime)
 
 	vrtc_cmos_write(real_sec, RTC_SECONDS);
 	vrtc_cmos_write(real_min, RTC_MINUTES);
+	spin_unlock_irqrestore(&rtc_lock, flags);
+
 	return 0;
 }
 
-- 
cgit v1.2.3


From 69c60c88eeb364ebf58432f9bc38033522d58767 Mon Sep 17 00:00:00 2001
From: Paul Gortmaker <paul.gortmaker@windriver.com>
Date: Thu, 26 May 2011 12:22:53 -0400
Subject: x86: Fix files explicitly requiring export.h for
 EXPORT_SYMBOL/THIS_MODULE
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

These files were implicitly getting EXPORT_SYMBOL via device.h
which was including module.h, but that will be fixed up shortly.

By fixing these now, we can avoid seeing things like:

arch/x86/kernel/rtc.c:29: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/pci-dma.c:20: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/e820.c:69: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL_GPL’

[ with input from Randy Dunlap <rdunlap@xenotime.net> and also
  from Stephen Rothwell <sfr@canb.auug.org.au> ]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 arch/x86/kernel/cpu/amd.c                | 1 +
 arch/x86/kernel/cpu/mcheck/mce-apei.c    | 1 +
 arch/x86/kernel/cpu/mcheck/mce.c         | 1 +
 arch/x86/kernel/cpu/mcheck/therm_throt.c | 1 +
 arch/x86/kernel/cpu/perf_event_intel.c   | 1 +
 arch/x86/kernel/devicetree.c             | 1 +
 arch/x86/kernel/e820.c                   | 1 +
 arch/x86/kernel/hpet.c                   | 1 +
 arch/x86/kernel/irq.c                    | 1 +
 arch/x86/kernel/nmi.c                    | 1 +
 arch/x86/kernel/pci-dma.c                | 1 +
 arch/x86/kernel/probe_roms.c             | 4 ++--
 arch/x86/kernel/rtc.c                    | 1 +
 arch/x86/kernel/smp.c                    | 1 +
 arch/x86/kernel/tboot.c                  | 1 +
 arch/x86/kernel/time.c                   | 1 +
 arch/x86/kernel/topology.c               | 1 +
 arch/x86/pci/i386.c                      | 1 +
 arch/x86/pci/legacy.c                    | 1 +
 arch/x86/platform/efi/efi.c              | 1 +
 arch/x86/platform/mrst/vrtc.c            | 1 +
 arch/x86/platform/olpc/olpc-xo1-pm.c     | 1 +
 arch/x86/platform/uv/bios_uv.c           | 1 +
 arch/x86/power/cpu.c                     | 1 +
 24 files changed, 25 insertions(+), 2 deletions(-)

(limited to 'arch/x86/platform/mrst/vrtc.c')

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 46ae4f65fc7f..c7e46cb35327 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1,3 +1,4 @@
+#include <linux/export.h>
 #include <linux/init.h>
 #include <linux/bitops.h>
 #include <linux/elf.h>
diff --git a/arch/x86/kernel/cpu/mcheck/mce-apei.c b/arch/x86/kernel/cpu/mcheck/mce-apei.c
index 83930deec3c6..507ea58688e2 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-apei.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-apei.c
@@ -28,6 +28,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/acpi.h>
 #include <linux/cper.h>
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 7b5063a6ad42..537c89e00095 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -38,6 +38,7 @@
 #include <linux/debugfs.h>
 #include <linux/edac_mce.h>
 #include <linux/irq_work.h>
+#include <linux/export.h>
 
 #include <asm/processor.h>
 #include <asm/mce.h>
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index 27c625178bf1..787e06c84ea6 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -18,6 +18,7 @@
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/percpu.h>
+#include <linux/export.h>
 #include <linux/sysdev.h>
 #include <linux/types.h>
 #include <linux/init.h>
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index e09ca20e86ee..2be5ebe99872 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -9,6 +9,7 @@
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/slab.h>
+#include <linux/export.h>
 
 #include <asm/hardirq.h>
 #include <asm/apic.h>
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index a621f3427685..52821799a702 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -2,6 +2,7 @@
  * Architecture specific OF callbacks.
  */
 #include <linux/bootmem.h>
+#include <linux/export.h>
 #include <linux/io.h>
 #include <linux/interrupt.h>
 #include <linux/list.h>
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 3e2ef8425316..303a0e48f076 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -12,6 +12,7 @@
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/crash_dump.h>
+#include <linux/export.h>
 #include <linux/bootmem.h>
 #include <linux/pfn.h>
 #include <linux/suspend.h>
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 4aecc54236a9..b946a9eac7d9 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -1,6 +1,7 @@
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
+#include <linux/export.h>
 #include <linux/sysdev.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 6c0802eb2f7f..429e0c92924e 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -9,6 +9,7 @@
 #include <linux/smp.h>
 #include <linux/ftrace.h>
 #include <linux/delay.h>
+#include <linux/export.h>
 
 #include <asm/apic.h>
 #include <asm/io_apic.h>
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 7ec5bd140b87..b9c8628974af 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -17,6 +17,7 @@
 #include <linux/delay.h>
 #include <linux/hardirq.h>
 #include <linux/slab.h>
+#include <linux/export.h>
 
 #include <linux/mca.h>
 
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 622872054fbe..80dc793b3f63 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -1,6 +1,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/dma-debug.h>
 #include <linux/dmar.h>
+#include <linux/export.h>
 #include <linux/bootmem.h>
 #include <linux/gfp.h>
 #include <linux/pci.h>
diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c
index 63228035f9d7..34e06e84ce31 100644
--- a/arch/x86/kernel/probe_roms.c
+++ b/arch/x86/kernel/probe_roms.c
@@ -10,9 +10,9 @@
 #include <linux/dmi.h>
 #include <linux/pfn.h>
 #include <linux/pci.h>
-#include <asm/pci-direct.h>
-
+#include <linux/export.h>
 
+#include <asm/pci-direct.h>
 #include <asm/e820.h>
 #include <asm/mmzone.h>
 #include <asm/setup.h>
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index ccdbc16b8941..348ce016a835 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -5,6 +5,7 @@
 #include <linux/mc146818rtc.h>
 #include <linux/acpi.h>
 #include <linux/bcd.h>
+#include <linux/export.h>
 #include <linux/pnp.h>
 #include <linux/of.h>
 
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 013e7eba83bb..16204dc15484 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -16,6 +16,7 @@
 #include <linux/mm.h>
 #include <linux/delay.h>
 #include <linux/spinlock.h>
+#include <linux/export.h>
 #include <linux/kernel_stat.h>
 #include <linux/mc146818rtc.h>
 #include <linux/cache.h>
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index e07a2fc876b9..e2410e27f97e 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -22,6 +22,7 @@
 #include <linux/dma_remapping.h>
 #include <linux/init_task.h>
 #include <linux/spinlock.h>
+#include <linux/export.h>
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/init.h>
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
index 5a64d057be57..dd5fbf4101fc 100644
--- a/arch/x86/kernel/time.c
+++ b/arch/x86/kernel/time.c
@@ -13,6 +13,7 @@
 #include <linux/interrupt.h>
 #include <linux/i8253.h>
 #include <linux/time.h>
+#include <linux/export.h>
 #include <linux/mca.h>
 
 #include <asm/vsyscall.h>
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index 8927486a4649..76ee97709a00 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -26,6 +26,7 @@
  * Send feedback to <colpatch@us.ibm.com>
  */
 #include <linux/nodemask.h>
+#include <linux/export.h>
 #include <linux/mmzone.h>
 #include <linux/init.h>
 #include <linux/smp.h>
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 494f2e7ea2b4..794b092d01ae 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -26,6 +26,7 @@
 
 #include <linux/types.h>
 #include <linux/kernel.h>
+#include <linux/export.h>
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
diff --git a/arch/x86/pci/legacy.c b/arch/x86/pci/legacy.c
index c89266be6048..2c2aeabc2609 100644
--- a/arch/x86/pci/legacy.c
+++ b/arch/x86/pci/legacy.c
@@ -2,6 +2,7 @@
  * legacy.c - traditional, old school PCI bus probing
  */
 #include <linux/init.h>
+#include <linux/export.h>
 #include <linux/pci.h>
 #include <asm/pci_x86.h>
 
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 3ae4128013e6..37718f0f053d 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -29,6 +29,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/efi.h>
+#include <linux/export.h>
 #include <linux/bootmem.h>
 #include <linux/memblock.h>
 #include <linux/spinlock.h>
diff --git a/arch/x86/platform/mrst/vrtc.c b/arch/x86/platform/mrst/vrtc.c
index 6d5dbcdd444a..a8ac6f1eb66d 100644
--- a/arch/x86/platform/mrst/vrtc.c
+++ b/arch/x86/platform/mrst/vrtc.c
@@ -18,6 +18,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/export.h>
 #include <linux/init.h>
 #include <linux/sfi.h>
 #include <linux/platform_device.h>
diff --git a/arch/x86/platform/olpc/olpc-xo1-pm.c b/arch/x86/platform/olpc/olpc-xo1-pm.c
index 6f3855a5a2f7..0ce8616c88ae 100644
--- a/arch/x86/platform/olpc/olpc-xo1-pm.c
+++ b/arch/x86/platform/olpc/olpc-xo1-pm.c
@@ -14,6 +14,7 @@
 
 #include <linux/cs5535.h>
 #include <linux/platform_device.h>
+#include <linux/export.h>
 #include <linux/pm.h>
 #include <linux/mfd/core.h>
 #include <linux/suspend.h>
diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c
index 8bc57baaa9ad..766612137a62 100644
--- a/arch/x86/platform/uv/bios_uv.c
+++ b/arch/x86/platform/uv/bios_uv.c
@@ -20,6 +20,7 @@
  */
 
 #include <linux/efi.h>
+#include <linux/export.h>
 #include <asm/efi.h>
 #include <linux/io.h>
 #include <asm/uv/bios.h>
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 87bb35e34ef1..f10c0afa1cb4 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/suspend.h>
+#include <linux/export.h>
 #include <linux/smp.h>
 
 #include <asm/pgtable.h>
-- 
cgit v1.2.3


From 57e6319dd61d5ca10fe8dd57bcce8c0e2c480799 Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.tang@intel.com>
Date: Thu, 10 Nov 2011 13:23:39 +0000
Subject: vrtc: change its year offset from 1960 to 1972

Real world year equals the value in vrtc YEAR register plus an offset.
We used 1960 as the offset to make leap year consistent, but for a
device's first use, its YEAR register is 0 and the system year will
be parsed as 1960 which is not a valid UNIX time and will cause many
applications to fail mysteriously. So we use 1972 instead to fix this
issue.

Updated patch which adds a sanity check suggested by Mathias

This isn't a change in behaviour for systems, because 1972 is the one we
actually use. It's the old version in upstream which is out of sync with
all devices.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/x86/platform/mrst/vrtc.c |  4 ++--
 drivers/rtc/rtc-mrst.c        | 19 +++++++++++--------
 2 files changed, 13 insertions(+), 10 deletions(-)

(limited to 'arch/x86/platform/mrst/vrtc.c')

diff --git a/arch/x86/platform/mrst/vrtc.c b/arch/x86/platform/mrst/vrtc.c
index a8ac6f1eb66d..225bd0f0f675 100644
--- a/arch/x86/platform/mrst/vrtc.c
+++ b/arch/x86/platform/mrst/vrtc.c
@@ -76,8 +76,8 @@ unsigned long vrtc_get_time(void)
 
 	spin_unlock_irqrestore(&rtc_lock, flags);
 
-	/* vRTC YEAR reg contains the offset to 1960 */
-	year += 1960;
+	/* vRTC YEAR reg contains the offset to 1972 */
+	year += 1972;
 
 	printk(KERN_INFO "vRTC: sec: %d min: %d hour: %d day: %d "
 		"mon: %d year: %d\n", sec, min, hour, mday, mon, year);
diff --git a/drivers/rtc/rtc-mrst.c b/drivers/rtc/rtc-mrst.c
index d33544802a2e..bb21f443fb70 100644
--- a/drivers/rtc/rtc-mrst.c
+++ b/drivers/rtc/rtc-mrst.c
@@ -76,12 +76,15 @@ static inline unsigned char vrtc_is_updating(void)
 /*
  * rtc_time's year contains the increment over 1900, but vRTC's YEAR
  * register can't be programmed to value larger than 0x64, so vRTC
- * driver chose to use 1960 (1970 is UNIX time start point) as the base,
+ * driver chose to use 1972 (1970 is UNIX time start point) as the base,
  * and does the translation at read/write time.
  *
- * Why not just use 1970 as the offset? it's because using 1960 will
+ * Why not just use 1970 as the offset? it's because using 1972 will
  * make it consistent in leap year setting for both vrtc and low-level
- * physical rtc devices.
+ * physical rtc devices. Then why not use 1960 as the offset? If we use
+ * 1960, for a device's first use, its YEAR register is 0 and the system
+ * year will be parsed as 1960 which is not a valid UNIX time and will
+ * cause many applications to fail mysteriously.
  */
 static int mrst_read_time(struct device *dev, struct rtc_time *time)
 {
@@ -99,10 +102,10 @@ static int mrst_read_time(struct device *dev, struct rtc_time *time)
 	time->tm_year = vrtc_cmos_read(RTC_YEAR);
 	spin_unlock_irqrestore(&rtc_lock, flags);
 
-	/* Adjust for the 1960/1900 */
-	time->tm_year += 60;
+	/* Adjust for the 1972/1900 */
+	time->tm_year += 72;
 	time->tm_mon--;
-	return RTC_24H;
+	return rtc_valid_tm(time);
 }
 
 static int mrst_set_time(struct device *dev, struct rtc_time *time)
@@ -119,9 +122,9 @@ static int mrst_set_time(struct device *dev, struct rtc_time *time)
 	min = time->tm_min;
 	sec = time->tm_sec;
 
-	if (yrs < 70 || yrs > 138)
+	if (yrs < 72 || yrs > 138)
 		return -EINVAL;
-	yrs -= 60;
+	yrs -= 72;
 
 	spin_lock_irqsave(&rtc_lock, flags);
 
-- 
cgit v1.2.3