The old ocfs2_xattr_extent_allocation is too optimistic about
the clusters we can get. So actually if the file system is
too fragmented, ocfs2_add_clusters_in_btree will return us
with EGAIN and we need to allocate clusters once again.
So this patch change it to a while loop so that we can allocate
clusters until we reach clusters_to_add.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Cc: stable@kernel.org
In ocfs2_block_group_alloc, we set c_blkno by bg->bg_blkno.
But actually bg->bg_blkno is already changed to little endian
in ocfs2_block_group_fill. So remove the extra cpu_to_le64.
Reported-by: Marcos Matsunaga <Marcos.Matsunaga@oracle.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
dlm->recovery_map is defined as
unsigned long recovery_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
We should treat O2NM_MAX_NODES as the bit map size in bits.
This patches fixes a bit operation that takes O2NM_MAX_NODES + 1 as bitmap size.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
When ocfs2 fills a hole, it does so by allocating clusters. When a
cluster is larger than the write, ocfs2 must zero the portions of the
cluster outside of the write. If the clustersize is smaller than a
pagecache page, this is handled by the normal pagecache mechanisms, but
when the clustersize is larger than a page, ocfs2's write code will zero
the pages adjacent to the write. This makes sure the entire cluster is
zeroed correctly.
Currently ocfs2 behaves exactly the same when writing past i_size.
However, this means ocfs2 is writing zeroed pages for portions of a new
cluster that are beyond i_size. The page writeback code isn't expecting
this. It treats all pages past the one containing i_size as left behind
due to a previous truncate operation.
Thankfully, ocfs2 calculates the number of pages it will be working on
up front. The rest of the write code merely honors the original
calculation. We can simply trim the number of pages to only cover the
actual file data.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Cc: stable@kernel.org
The commit 5d554a7bb0 (ACPI: processor: add internal
processor_physically_present()) is broken on uniprocessor (UP)
configurations, as acpi_get_cpuid() will always return -1.
We use the value of num_possible_cpus() to tell us whether we got
an invalid cpuid from acpi_get_cpuid() in the SMP case, or if
instead, we are UP, in which case num_possible_cpus() is #defined
as 1.
We use num_possible_cpus() instead of num_online_cpus() to
protect ourselves against the scenario of CPU hotplug, and we've
taken down all the CPUs except one.
Thanks to Jan Pogadl for initial report and analysis and Chen
Gong for review.
https://bugzilla.kernel.org/show_bug.cgi?id=16357
Reported-by: Jan Pogadl <pogadl.jan@googlemail.com>:
Reviewed-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Alex Chiang <achiang@canonical.com>
Signed-off-by: Len Brown <len.brown@intel.com>
After remove a rmap, we should flush all vcpu's tlb
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
As long as the zImage is placed within the 128MB range from the start of
memory, ZRELADDR (Address where the decompressed kernel will be placed,
usually == PHYS_OFFSET + TEXT_OFFSET) can be determined at run-time by
masking PC with 0xf80000000.
Running through all the Makefile.boot, all those zreladdr-y
addresses == 0x[0-f][08]00_0000 + TEXT_OFFSET can be determined at
run-time.
Option CONFIG_AUTO_ZRELADDR and CONFIG_ZRELADDR are introduced,
CONFIG_ZRELADDR _must_ be explicitly specified if:
- ((zreladdr-y - TEXT_OFFSET) & ~0xf8000000) != 0, which means
masking PC with 0xf8000000 will result in an incorrect address.
Currently this is only a problem on u300.
- or the assumption of the zImage being loaded by the bootloader within
the first 128MB of RAM is incorrect
- or when ZBOOT_ROM is used, where the above assumption is usually wrong.
[ukleinek: changed mask from 0xf0000000 to 0xf8000000 for mx1 and shark
+ some review fixes from the mailing list]
Original-Idea-and-Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Eric Miao <eric.miao@canonical.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Merge error.
See CFG_METHOD_8 (0x3c800000 + 0x00300000) since version 8.002.00
of Realtek's driver.
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Cc: Hayes <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Report ID wasn't sent as part of the payload for reports which were sent
over the control endpoint. This is required by section 8.1 of the HID spec.
Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The UVC gadget driver borrowed code from the UVC host driver without
changing the symbol names. This results in a namespace clash with
multiple definitions of several symbols when compiling both drivers in
the kernel.
Make all generic UVC functions and variables static in the UVC gadget
driver, as the symbols are not referenced outside of the gadget driver.
Rename the uvc_trace_param global variable to uvc_gadget_trace_param.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
hwmon: Fix autoloading of fschmd on recent Fujitsu machines
hwmon: (coretemp) Properly label the sensors
hwmon: (coretemp) Skip duplicate CPU entries
hwmon: (it87) Fix in7 on IT8720F
hwmon: (k8temp) Fix temperature reporting for ASB1 processor revisions
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
i2c/mips: Fix error return codes from Sibyte i2c bus driver
i2c: Fix probability check
Patch for linux-2.6.35-rc4 mainline kernel to enable Paul Qureshi's
Retro Adapter [http://keio.dk/retroadapter.html], an open source USB
device which allows controllers and joysticks from classic computers
and consoles to work on modern PCs, to appear as two separate devices
under Linux.
Signed-off-by: Peter Edwards <samwise@bagshot-row.org>
Acked-by: Paul Qureshi <retro@world3.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This USB flight yoke needs the NOGET quirk, like most of CH's other
products. This patch adds that.
Signed-off-by: Jonathan Rockway <jon@jrock.us>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
When booting a relocatable kernel it needs to jump to the correct
start address, which for BookE parts is usually unchanged
regardless of the physical memory offset.
Recent changes cause problems with how we calculate the start
address, it was always adding the RMO into the start address
which is incorrect. This patch only adds in the RMO offset
if we are in the kexec code path, as it needs the RMO to work
correctly.
Instead of adding the RMO offset in in the common code path, we
can just set r6 to the RMO offset in the kexec code path instead
of to zero, and finally perform the masking in the common code
path
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This saves runtime memory and fixes lots of sparse warnings like this:
CHECK arch/powerpc/sysdev/micropatch.c
arch/powerpc/sysdev/micropatch.c:27:6: warning: symbol 'patch_2000'
was not declared. Should it be static?
arch/powerpc/sysdev/micropatch.c:146:6: warning: symbol 'patch_2f00'
was not declared. Should it be static?
...
Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Warnings are treated as errors for arch/powerpc code, so build fails
with CONFIG_I2C_SPI_UCODE_PATCH=y:
CC arch/powerpc/sysdev/micropatch.o
cc1: warnings being treated as errors
arch/powerpc/sysdev/micropatch.c: In function 'cpm_load_patch':
arch/powerpc/sysdev/micropatch.c:630: warning: unused variable 'smp'
make[1]: *** [arch/powerpc/sysdev/micropatch.o] Error 1
And with CONFIG_USB_SOF_UCODE_PATCH=y:
CC arch/powerpc/sysdev/micropatch.o
cc1: warnings being treated as errors
arch/powerpc/sysdev/micropatch.c: In function 'cpm_load_patch':
arch/powerpc/sysdev/micropatch.c:629: warning: unused variable 'spp'
arch/powerpc/sysdev/micropatch.c:628: warning: unused variable 'iip'
make[1]: *** [arch/powerpc/sysdev/micropatch.o] Error 1
This patch fixes these issues by introducing proper #ifdefs.
Cc: <stable@kernel.org> [ .33, .34 ]
Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
spi_t was removed in commit 644b2a680c
("powerpc/cpm: Remove SPI defines and spi structs"), the commit assumed
that spi_t isn't used anywhere outside of the spi_mpc8xxx driver. But
it appears that the struct is needed for micropatch code. So, let's
reintroduce the struct.
Fixes the following build issue:
CC arch/powerpc/sysdev/micropatch.o
micropatch.c: In function 'cpm_load_patch':
micropatch.c:629: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
micropatch.c:629: error: 'spp' undeclared (first use in this function)
micropatch.c:629: error: (Each undeclared identifier is reported only once
micropatch.c:629: error: for each function it appears in.)
Reported-by: LEROY Christophe <christophe.leroy@c-s.fr>
Reported-by: Tony Breeds <tony@bakeyournoodle.com>
Cc: <stable@kernel.org> [ .33, .34 ]
Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
CPU: Testing write buffer coherency: ok
------------[ cut here ]------------
WARNING: at kernel/lockdep.c:3145 check_flags+0xcc/0x1dc()
Modules linked in:
[<c0035120>] (unwind_backtrace+0x0/0xf8) from [<c0355374>] (dump_stack+0x20/0x24)
[<c0355374>] (dump_stack+0x20/0x24) from [<c0060c04>] (warn_slowpath_common+0x58/0x70)
[<c0060c04>] (warn_slowpath_common+0x58/0x70) from [<c0060c3c>] (warn_slowpath_null+0x20/0x24)
[<c0060c3c>] (warn_slowpath_null+0x20/0x24) from [<c008f224>] (check_flags+0xcc/0x1dc)
[<c008f224>] (check_flags+0xcc/0x1dc) from [<c00945dc>] (lock_acquire+0x50/0x140)
[<c00945dc>] (lock_acquire+0x50/0x140) from [<c0358434>] (_raw_spin_lock+0x50/0x88)
[<c0358434>] (_raw_spin_lock+0x50/0x88) from [<c00fd114>] (set_task_comm+0x2c/0x60)
[<c00fd114>] (set_task_comm+0x2c/0x60) from [<c007e184>] (kthreadd+0x30/0x108)
[<c007e184>] (kthreadd+0x30/0x108) from [<c0030104>] (kernel_thread_exit+0x0/0x8)
---[ end trace 1b75b31a2719ed1c ]---
possible reason: unannotated irqs-on.
irq event stamp: 3
hardirqs last enabled at (2): [<c0059bb0>] finish_task_switch+0x48/0xb0
hardirqs last disabled at (3): [<c002f0b0>] ret_slow_syscall+0xc/0x1c
softirqs last enabled at (0): [<c005f3e0>] copy_process+0x394/0xe5c
softirqs last disabled at (0): [<(null)>] (null)
Fix this by ensuring that the lockdep interrupt state is manipulated in
the appropriate places. We essentially treat userspace as an entirely
separate environment which isn't relevant to lockdep (lockdep doesn't
monitor userspace.) We don't tell lockdep that IRQs will be enabled
in that environment.
Instead, when creating kernel threads (which is a rare event compared
to entering/leaving userspace) we have to update the lockdep state. Do
this by starting threads with IRQs disabled, and in the kthread helper,
tell lockdep that IRQs are enabled, and enable them.
This provides lockdep with a consistent view of the current IRQ state
in kernel space.
This also revert portions of 0d928b0b61
which didn't fix the problem.
Tested-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Sibyte i2c bus driver returns non-descriptive error values.
Update to return error values as defined in Documentation/i2c/fault-codes.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new unified probing function differs from the original code, and
the preliminary test whether probing is possible must be updated
accordingly.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
For some reason if we declare a static variable and then assign it
later, and the assignment contains a __attribute__((__aligned__(#))),
some versions of gcc will ignore it.
This caused the syscall meta data to not be compact in its section
and caused a kernel oops when the section was being read.
The fix for these versions of gcc seems to be to add the aligned
attribute to the declaration as well.
This fixes the BZ regression:
https://bugzilla.kernel.org/show_bug.cgi?id=16353
Reported-by: Zeev Tarantov <zeev.tarantov@gmail.com>
Tested-by: Zeev Tarantov <zeev.tarantov@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <AANLkTinkKVmB0fpVeqUkMeqe3ZYeXJdI8xDuzJEOjYwh@mail.gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Fujitsu slightly changed the DMI strings in their recent machines,
(for example the D2778) and this breaks the automatic loading of the
needed fschmd driver. Being more tolerant on string comparison fixes
the issue.
This closes bug #15634:
https://bugzilla.kernel.org/show_bug.cgi?id=15634
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Sergey Spiridonov <sena@hurd.homeunix.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Don't assume that CPU entry number and core ID always match. It
worked in the simple cases (single CPU, no HT) but fails on
multi-CPU systems.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Huaxu Wan <huaxu.wan@intel.com>
Cc: stable@kernel.org
On hyper-threaded CPUs, each core appears twice in the CPU list. Skip
the second entry to avoid duplicate sensors.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Huaxu Wan <huaxu.wan@intel.com>
Cc: stable@kernel.org
The IT8720F has no VIN7 pin, so VCCH should always be routed
internally to VIN7 with an internal divider. Curiously, there still
is a configuration bit to control this, which means it can be set
incorrectly. And even more curiously, many boards out there are
improperly configured, even though the IT8720F datasheet claims that
the internal routing of VCCH to VIN7 is the default setting. So we
force the internal routing in this case.
It turns out that all boards with the wrong setting are from Gigabyte,
so I suspect a BIOS bug. But it's easy enough to workaround in the
driver, so let's do it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Jean-Marc Spaggiari <jean-marc@spaggiari.org>
Cc: stable@kernel.org
Reported temperature for ASB1 CPUs is too high.
Add ASB1 CPU revisions (these are also non-desktop variants) to the
list of CPUs for which the temperature fixup is not required.
Example: (from LENOVO ThinkPad Edge 13, 01972NG, system was idle)
Current kernel reports
$ sensors
k8temp-pci-00c3
Adapter: PCI adapter
Core0 Temp: +74.0 C
Core0 Temp: +70.0 C
Core1 Temp: +69.0 C
Core1 Temp: +70.0 C
With this patch I have
$ sensors
k8temp-pci-00c3
Adapter: PCI adapter
Core0 Temp: +54.0 C
Core0 Temp: +51.0 C
Core1 Temp: +48.0 C
Core1 Temp: +49.0 C
Cc: stable@kernel.org [.32.x .33.x, .34.x]
Cc: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This parameter is used by primary kernel to pass address of vmcore
header to the dump capture kernel.
Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This function is used by vmcore code to read a page from the old
kernel memory.
Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When we are crashing there is no indirection page in place. Only
control page is present.
Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Implement function machine_crash_shutdown() which disables IRQs and
saves machine state to ELF notes structure.
Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Implement machine specific function crash_setup_regs() which is
responsible for storing machine state when crash occured.
Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Implemented ARM support for command line option
"crashkernel=size@start" which allows user to reserve some memory
for a dump capture kernel.
Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The MTU wallclock timing fix-up patch was hardwired to the DB8500
causing a regression. This makes it work on the DB5500 as well.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The TLS register is only available on ARM1136 r1p0 and later.
Set HWCAP_TLS flags if hardware TLS is available and test for
it if CONFIG_CPU_32v6K is not set for V6.
Note that we set the TLS instruction in __kuser_get_tls
dynamically as suggested by Jamie Lokier <jamie@shareable.org>.
Also the __switch_to code is optimized out in most cases as
suggested by Nicolas Pitre <nico@fluxnic.net>.
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Allow SH-Mobile ARM users to adjust FORCE_MAX_ZONEORDER.
The Kconfig entry is taken from SH and non-4K page size
stuff has been trimmed away. For now only SH-Mobile ARM is
allowed to change this variable, SA1111 configs are kept at
"9" and the rest at "11".
CONFIG_FORCE_MAX_ZONEORDER lets the user tweak the maximum
amount of physically contiguous memory that can be allocated
by the kernel.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
MVFR0 and MVFR1 are only available starting with ARM1136 r1p0 release
according to "B.5 VFP changes" in DDI0211F_arm1136_r1p0_trm.pdf. This is
also when TLS register got added, so we can use HAS_TLS also to test for
MVFR0 and MVFR1.
Otherwise VFPFMRX and VFPFMXR access fails and we get:
Internal error: Oops - undefined instruction: 0 [#1]
PC is at no_old_VFP_process+0x8/0x3c
LR is at __und_svc+0x48/0x80
...
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch enables the HAVE_REGS_AND_STACK_ACCESS_API option
for ARM which is required by the kprobe events tracer. Code based
on the PowerPC port.
Cc: Jean Pihet <jpihet@mvista.com>
Tested-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds mappings from DWARF register numbers to the register
names used by the ARM `Regs and Stack Access API'.
Cc: Jean Pihet <jpihet@mvista.com>
Tested-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
So to allow NR_IRQS to be dynamic and platforms to specify the number
of IRQs really needed.
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is a number of basic fixes to the PB1176 that makes it tick
properly:
- Detect MMC insertion/removal even when PL061 GPIO is not compiled
in. The register to read this status directly is removed on the
PB1176.
- Define the UART3 on the DevChip (where is actually is) and define
the new UART4 serial port on the FPGA.
- Also define the clocks for these two UARTs apropriately.
- Remove the false notion that the PB1176 should have its CLCD
on the ISSP, this is not the case, it is in the DevChip.
- Remove the defintions and the previously commented-out PL081
DMAC. As confirmed by mail this was found to be broken on the
PB1176 board and removed from the subsequent FPGA images.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds support for the Cortex-A9 local timers available when
using the CA9X4 daughterboard with the Versatile Express.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add support for Bluewater Systems Snapper 9260/9G20 modules
Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add definition for NR_BUILTIN_GPIO for AT91 family
Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This rework allows to address tow memory controllers. AT91SAM9263 and
AT91SAM9G45 family have tow SDRAM or DDR/SDRAM controllers. Power management
should take care of this.
This patch modify the way RAM IP header files are implemented to allow
access to registers of both controllers ; it also adds some macros.
We also modify the power management files to use those modified header files.
Slow clock (assembly) and regular power management functions are synchronized
for setting of RAM self-refresh procedure:
(lpr & ~AT91_DDRSDRC_LPCB) | AT91_DDRSDRC_LPCB_SELF_REFRESH
Note that AT91RM9200 is not impacted by this modification.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Currently, the 32-bit and 64-bit atomic operations on ARM do not
include memory constraints in the inline assembly blocks. In the
case of barrier-less operations [for example, atomic_add], this
means that the compiler may constant fold values which have actually
been modified by a call to an atomic operation.
This issue can be observed in the atomic64_test routine in
<kernel root>/lib/atomic64_test.c:
00000000 <test_atomic64>:
0: e1a0c00d mov ip, sp
4: e92dd830 push {r4, r5, fp, ip, lr, pc}
8: e24cb004 sub fp, ip, #4
c: e24dd008 sub sp, sp, #8
10: e24b3014 sub r3, fp, #20
14: e30d000d movw r0, #53261 ; 0xd00d
18: e3011337 movw r1, #4919 ; 0x1337
1c: e34c0001 movt r0, #49153 ; 0xc001
20: e34a1aa3 movt r1, #43683 ; 0xaaa3
24: e16300f8 strd r0, [r3, #-8]!
28: e30c0afe movw r0, #51966 ; 0xcafe
2c: e30b1eef movw r1, #48879 ; 0xbeef
30: e34d0eaf movt r0, #57007 ; 0xdeaf
34: e34d1ead movt r1, #57005 ; 0xdead
38: e1b34f9f ldrexd r4, [r3]
3c: e1a34f90 strexd r4, r0, [r3]
40: e3340000 teq r4, #0
44: 1afffffb bne 38 <test_atomic64+0x38>
48: e59f0004 ldr r0, [pc, #4] ; 54 <test_atomic64+0x54>
4c: e3a0101e mov r1, #30
50: ebfffffe bl 0 <__bug>
54: 00000000 .word 0x00000000
The atomic64_set (0x38-0x44) writes to the atomic64_t, but the
compiler doesn't see this, assumes the test condition is always
false and generates an unconditional branch to __bug. The rest of the
test is optimised away.
This patch adds suitable memory constraints to the atomic operations on ARM
to ensure that the compiler is informed of the correct data hazards. We have
to use the "Qo" constraints to avoid hitting the GCC anomaly described at
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44492 , where the compiler
makes assumptions about the writeback in the addressing mode used by the
inline assembly. These constraints forbid the use of auto{inc,dec} addressing
modes, so it doesn't matter if we don't use the operand exactly once.
Cc: stable@kernel.org
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The atomic64_add_unless function compares an atomic variable with
a given value and, if they are not equal, adds another given value
to the atomic variable. The function returns zero if the addition
did not occur and non-zero otherwise.
On ARM, the return value is initialised to 1 in C code. Inline assembly
code then performs the atomic64_add_unless operation, setting the
return value to 0 iff the addition does not occur. This means that
when the addition *does* occur, the value of ret must be preserved
across the inline assembly and therefore requires a "+r" constraint
rather than the current one of "=&r".
Thanks to Nicolas Pitre for helping to spot this.
Cc: stable@kernel.org
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
