lglock: introduce special lglock and brlock spin locks
This patch introduces "local-global" locks (lglocks). These can be used to:
- Provide fast exclusive access to per-CPU data, with exclusive access to
another CPU's data allowed but possibly subject to contention, and to provide
very slow exclusive access to all per-CPU data.
- Or to provide very fast and scalable read serialisation, and to provide
very slow exclusive serialisation of data (not necessarily per-CPU data).
Brlocks are also implemented as a short-hand notation for the latter use
case.
Thanks to Paul for local/global naming convention.
Cc: linux-kernel@vger.kernel.org
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
tty: fix fu_list abuse
tty code abuses fu_list, which causes a bug in remount,ro handling.
If a tty device node is opened on a filesystem, then the last link to the inode
removed, the filesystem will be allowed to be remounted readonly. This is
because fs_may_remount_ro does not find the 0 link tty inode on the file sb
list (because the tty code incorrectly removed it to use for its own purpose).
This can result in a filesystem with errors after it is marked "clean".
Taking idea from Christoph's initial patch, allocate a tty private struct
at file->private_data and put our required list fields in there, linking
file and tty. This makes tty nodes behave the same way as other device nodes
and avoid meddling with the vfs, and avoids this bug.
The error handling is not trivial in the tty code, so for this bugfix, I take
the simple approach of using __GFP_NOFAIL and don't worry about memory errors.
This is not a problem because our allocator doesn't fail small allocs as a rule
anyway. So proper error handling is left as an exercise for tty hackers.
[ Arguably filesystem's device inode would ideally be divorced from the
driver's pseudo inode when it is opened, but in practice it's not clear whether
that will ever be worth implementing. ]
Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs: fs_struct rwlock to spinlock
struct fs_struct.lock is an rwlock with the read-side used to protect root and
pwd members while taking references to them. Taking a reference to a path
typically requires just 2 atomic ops, so the critical section is very small.
Parallel read-side operations would have cacheline contention on the lock, the
dentry, and the vfsmount cachelines, so the rwlock is unlikely to ever give a
real parallelism increase.
Replace it with a spinlock to avoid one or two atomic operations in typical
path lookup fastpath.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
These flags aren't real I/O types, but tell ll_rw_block to always
lock the buffer instead of giving up on a failed trylock.
Instead add a new write_dirty_buffer helper that implements this semantic
and use it from the existing SWRITE* callers. Note that the ll_rw_block
code had a bug where it didn't promote WRITE_SYNC_PLUG properly, which
this patch fixes.
In the ufs code clean up the helper that used to call ll_rw_block
to mirror sync_dirty_buffer, which is the function it implements for
compound buffers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Instead of abusing a buffer_head flag just add a variant of
sync_dirty_buffer which allows passing the exact type of write
flag required.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* master.kernel.org:/home/rmk/linux-2.6-arm:
VIDEO: amba clcd: don't disable an already disabled clock
ARM: Tighten check for allowable CPSR values
ARM: 6329/1: wire up sys_accept4() on ARM
ARM: 6328/1: Build with -fno-dwarf2-cfi-asm
ARM: 6326/1: kgdb: fix GDB_MAX_REGS no longer used
Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:
arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to. This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel(). A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().
do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.
Further kernel_execve() and sys_execve() need to be changed to match.
This has been test built on x86_64, frv, arm and mips.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the clock enable/disable tracking in the AMBA CLCD driver so
that the driver doesn't try to disable an already disabled clock,
thereby causing the clock (if shared) to become unbalanced.
This resolves a problem with CLCD on LPC32xx ARM platforms.
Reported-by: Kevin Wells <wellsk40@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
With the current screwed but its ABI, ioctls for the drm, Linus pointed out that we could allow userspace to specify the allocation size, but we pass it to the driver which then uses it blindly to store a struct. Now if userspace specifies the allocation size as smaller than the driver needs, the driver can possibly overwrite memory.
This patch restructures the driver ioctls so we store the structure size we are expecting, and make sure we allocate at least that size. The copy from/to userspace are still restricted to the size the user specifies, this allows ioctl structs to grow on both sides of the equation.
Up until now we didn't really use the DRM_IOCTL defines in the kernel, so this cleans them up and adds them for nouveau.
v2:
fix nouveau pushbuf arg (thanks to Ben for pointing it out)
Reported-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Implement multiqueue facility for macvtap driver. The idea is that
a macvtap device can be opened multiple times and the fd's can be
used to register eg, as backend for vhost.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Factor out flow calculation code from get_rps_cpu, since other
functions can use the same code.
Revisions:
v2 (Ben): Separate flow calcuation out and use in select queue.
v3 (Arnd): Don't re-implement MIN.
v4 (Changli): skb->data points to ethernet header in macvtap, and
make a fast path. Tested macvtap with this patch.
v5 (Changli):
- Cache skb->rxhash in skb_get_rxhash
- macvtap may not have pow(2) queues, so change code for
queue selection.
(Arnd):
- Use first available queue if all fails.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, mac80211 translates the cfg80211
cipher suite selectors into ALG_* values.
That isn't all too useful, and some drivers
benefit from the distinction between WEP40
and WEP104 as well. Therefore, convert it
all to use the cipher suite selectors.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Enable using network namespaces with
wireless devices even when sysfs is
enabled using the same infrastructure
that was built for netdevs.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Sometimes drivers have more information than the
stack about how their antennas/chains are used,
and may require that the SM PS mode be changed.
This could happen, for example, when detecting
that the user disconnected an antenna. Thus this
patch introduces API to allow drivers to request
SM PS mode changes.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Sometimes we don't just need to know whether or
not the device is idle, but also per interface.
This adds that reporting capability to mac80211.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch implement basic infrastructure to support use of NAPI by
mac80211-based hardware drivers.
Because mac80211 devices can support multiple netdevs, a dummy netdev
is used for interfacing with the NAPI code in the core of the network
stack. That structure is hidden from the hardware drivers, but the
actual napi_struct is exposed in the ieee80211_hw structure so that the
poll routines in drivers can retrieve that structure. Hardware drivers
can also specify their own weight value for NAPI polling.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Fairly simple conflicts, the most serious ones are the i.MX ones which I
suspect now need another rename.
Conflicts:
arch/arm/mach-mx2/clock_imx27.c
arch/arm/mach-mx2/devices.c
arch/arm/mach-omap2/board-rx51-peripherals.c
arch/arm/mach-omap2/board-zoom2.c
sound/soc/fsl/mpc5200_dma.c
sound/soc/fsl/mpc5200_dma.h
sound/soc/fsl/mpc8610_hpcd.c
sound/soc/pxa/spitz.c
The below updates a broken web address to one(hopefully) thats
the new correct address.
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
gcc-4.6: ACPI: fix unused but set variables in ACPI
ACPI thermal: make procfs I/F depend on CONFIG_ACPI_PROCFS
ACPI video: make procfs I/F depend on CONFIG_ACPI_PROCFS
ACPI processor: remove deprecated ACPI procfs I/F
ACPI power_resource: remove unused procfs I/F
ACPI: remove deprecated ACPI procfs I/F
ACPI: introduce drivers/acpi/sysfs.c
ACPI: introduce module parameter acpi.aml_debug_output
ACPI: introduce drivers/acpi/debugfs.c
ACPI, APEI, ERST debug support
ACPI, APEI, Manage GHES as platform devices
ACPI, APEI, Rename CPER and GHES severity constants
ACPI, APEI, Fix a typo of error path of apei_resources_request
ACPI / ACPICA: Fix reference counting problems with GPE handlers
ACPI: Add the check of ADR flag in course of finding ACPI handle for PCI device
ACPI / Sleep: Drop acpi_suspend_finish()
ACPI / Sleep: Consolidate suspend and hibernation routines
ACPI / Wakeup: Simplify enabling of wakeup devices
ACPI / Sleep: Rework enabling wakeup devices
ACPI / Sleep: Free NVS copy if suspending of devices fails
Fixed up totally buggered "ACPI: fix unused but set variables in ACPI"
patch that doesn't even compile in the merge.
Thanks to Sedat Dilek <sedat.dilek@googlemail.com> for noticing the
breakage before I even pulled. And a big "Grrr.." at Len for not even
bothering to compile the tree before asking me to pull.
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: don't validate CROSS_COMPILE needlessly
arch/tile: export only COMMAND_LINE_SIZE to userspace.
arch/tile: rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN
arch/tile: Rename the hweight() implementations to __arch_hweight()
arch/tile: extend syscall ABI to set r1 on return as well.
arch/tile: Various cleanups.
arch/tile: support backtracing on TILE-Gx
arch/tile: Fix a couple of issues with the COMPAT code for TILE-Gx.
arch/tile: Use separate, better minsec values for clocksource and sched_clock.
arch/tile: correct a bug in freeing bootmem by VA for the optional second initrd.
arch: tile: mm: pgtable.c: Removed duplicated #include
arch: tile: kernel/proc.c Removed duplicated #include
Add fanotify syscalls to <asm-generic/unistd.h>.
arch/tile: support new kunmap_atomic() naming convention.
tile: remove unused ISA_DMA_THRESHOLD define
Conflicts in arch/tile/configs/tile_defconfig (pick the mainline version
with the reduced defconfig).
Remove deprecated ACPI processor procfs I/F, including:
/proc/acpi/processor/CPUX/power
/proc/acpi/processor/CPUX/limit
/proc/acpi/processor/CPUX/info
/proc/acpi/processor/CPUX/throttling still exists,
as we don't have sysfs I/F available for now.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Introduce module parameter acpi.aml_debug_output.
With acpi.aml_debug_output set, we can get AML debug object output
(Store (AAA, Debug)), even with CONFIG_ACPI_DEBUG cleared.
Together with the runtime custom method mechanism,
we can debug AML code problems without rebuilding the kernel.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/cleanup:
defconfig reduction
kbuild: drop unifdef-y support
archs: replace unifdef-y with header-y
include: replace unifdef-y with header-y
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging: (22 commits)
hwmon: (via-cputemp) Remove bogus "SHOW" global variable
hwmon: jc42 depends on I2C
hwmon: (pc87427) Add a maintainer
hwmon: (pc87427) Move sysfs file removal to a separate function
hwmon: (pc87427) Add temperature monitoring support
hwmon: (pc87427) Add support for the second logical device
hwmon: (pc87427) Add support for manual fan speed control
hwmon: (pc87427) Minor style cleanups
hwmon: (pc87427) Handle disabled fan inputs properly
hwmon: (w83627ehf) Add support for W83667HG-B
hwmon: (w83627ehf) Driver cleanup
hwmon: Add driver for SMSC EMC2103 temperature monitor and fan controller
hwmon: Remove in[0-*]_fault from sysfs-interface
hwmon: Add 4 current alarm/beep attributes to sysfs-interface
hwmon: Add 3 critical limit attributes to sysfs-interface
hwmon: (asc7621) Clean up and improve detect function
hwmon: (it87) Export labels for internal sensors
hwmon: (lm75) Add suspend/resume feature
hwmon: (emc1403) Add power support
hwmon: (ltc4245) Expose all GPIO pins as analog voltages
...
unifdef-y and header-y has same semantic.
So there is no need to have both.
Drop the unifdef-y variant and sort all lines again
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Add support for exposing all GPIO pins as analog voltages. Though this is
not an ideal use of the chip, some hardware engineers may decide that the
LTC4245 meets their design requirements when studying the datasheet.
The GPIO pins are sampled in round-robin fashion, meaning that a slow
reader will see stale data. A userspace application can detect this,
because it will get -EAGAIN when reading from a sysfs file which contains
stale data.
Users can choose to use this feature on a per-chip basis by using either
platform data or the OF device tree (where applicable).
Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
* 'next-spi' of git://git.secretlab.ca/git/linux-2.6:
spi/amba_pl022: Fix probe and remove hook section annotations.
spi/mpc5121: change annotations for probe and remove functions
spi/bitbang: reinitialize transfer parameters for every message
spi/spi-gpio: add support for controllers without MISO or MOSI pin
spi/bitbang: add support for SPI_MASTER_NO_{TX, RX} modes
SPI100k: Fix 8-bit and RX-only transfers
spi/mmc_spi: mmc_spi adaptations for SPI bus locking API
spi/mmc_spi: SPI bus locking API, using mutex
Fix trivial conflict in drivers/spi/mpc512x_psc_spi.c due to 'struct
of_device' => 'struct platform_device' rename and __init/__exit to
__devinit/__devexit fix.
Mark arguments to certain system calls as being const where they should be but
aren't. The list includes:
(*) The filename arguments of various stat syscalls, execve(), various utimes
syscalls and some mount syscalls.
(*) The filename arguments of some syscall helpers relating to the above.
(*) The buffer argument of various write syscalls.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 3bcf3860a4 (and the
accompanying commit c1e5c95402 "vfs/fsnotify: fsnotify_close can delay
the final work in fput" that was a horribly ugly hack to make it work at
all).
The 'struct file' approach not only causes that disgusting hack, it
somehow breaks pulseaudio, probably due to some other subtlety with
f_count handling.
Fix up various conflicts due to later fsnotify work.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (33 commits)
dm mpath: support discard
dm stripe: support discards
dm: split discard requests on target boundaries
dm stripe: optimize sector division
dm stripe: move sector translation to a function
dm: error return error for discards
dm delay: support discard
dm: zero silently drop discards
dm: use dm_target_offset macro
dm: factor out max_io_len_target_boundary
dm: use common __issue_target_request for flush and discard support
dm: linear support discard
dm crypt: simplify crypt_ctr
dm crypt: simplify crypt_config destruction logic
dm: allow autoloading of dm mod
dm: rename map_info flush_request to target_request_nr
dm ioctl: refactor dm_table_complete
dm snapshot: implement merge
dm: do not initialise full request queue when bio based
dm ioctl: make bio or request based device type immutable
...
* 'for-linus' of git://neil.brown.name/md:
Further tidyup of raid6 naming in lib/raid6
Make lib/raid6/test build correctly.
Rename raid6 files now they're in a 'raid6' directory.
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
i2c: I2C bus multiplexer driver pca954x
i2c: Multiplexed I2C bus core support
i2c: Use a separate mutex for userspace client lists
i2c: Make i2c_default_probe self-sufficient
i2c: Drop dummy variable
i2c: Move adapter locking helpers to i2c-core
V4L/DVB: Use custom I2C probing function mechanism
i2c: Add support for custom probe function
i2c-dev: Use memdup_user
i2c-dev: Remove unnecessary kmalloc casts
* 'params' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (22 commits)
param: don't deref arg in __same_type() checks
param: update drivers/acpi/debug.c to new scheme
param: use module_param in drivers/message/fusion/mptbase.c
ide: use module_param_named rather than module_param_call
param: update drivers/char/ipmi/ipmi_watchdog.c to new scheme
param: lock if_sdio's lbs_helper_name and lbs_fw_name against sysfs changes.
param: lock myri10ge_fw_name against sysfs changes.
param: simple locking for sysfs-writable charp parameters
param: remove unnecessary writable charp
param: add kerneldoc to moduleparam.h
param: locking for kernel parameters
param: make param sections const.
param: use free hook for charp (fix leak of charp parameters)
param: add a free hook to kernel_param_ops.
param: silence .init.text references from param ops
Add param ops struct for hvc_iucv driver.
nfs: update for module_param_named API change
AppArmor: update for module_param_named API change
param: use ops in struct kernel_param, rather than get and set fns directly
param: move the EXPORT_SYMBOL to after the definitions.
...
