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2012-02-24static keys: Introduce 'struct static_key', static_key_true()/false() and ↵Ingo Molnar6-54/+116
static_key_slow_[inc|dec]() So here's a boot tested patch on top of Jason's series that does all the cleanups I talked about and turns jump labels into a more intuitive to use facility. It should also address the various misconceptions and confusions that surround jump labels. Typical usage scenarios: #include <linux/static_key.h> struct static_key key = STATIC_KEY_INIT_TRUE; if (static_key_false(&key)) do unlikely code else do likely code Or: if (static_key_true(&key)) do likely code else do unlikely code The static key is modified via: static_key_slow_inc(&key); ... static_key_slow_dec(&key); The 'slow' prefix makes it abundantly clear that this is an expensive operation. I've updated all in-kernel code to use this everywhere. Note that I (intentionally) have not pushed through the rename blindly through to the lowest levels: the actual jump-label patching arch facility should be named like that, so we want to decouple jump labels from the static-key facility a bit. On non-jump-label enabled architectures static keys default to likely()/unlikely() branches. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jason Baron <jbaron@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: a.p.zijlstra@chello.nl Cc: mathieu.desnoyers@efficios.com Cc: davem@davemloft.net Cc: ddaney.cavm@gmail.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.hu Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-24pinctrl: disallow map table entries with NULL dev_name fieldStephen Warren1-7/+0
Hog entries are mapping table entries with .ctrl_dev_name == .dev_name. All other mapping table entries need .dev_name set so that they will match some pinctrl_get() call. All extant PIN_MAP*() macros set .dev_name. So, there is no reason to allow mapping table entries without .dev_name set. Update the code and documentation to disallow this. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-24PCI: add generic pcibios_resource_to_bus()Bjorn Helgaas1-0/+4
This replaces the generic versions of pcibios_resource_to_bus() and pcibios_bus_to_resource() in asm-generic/pci.h with versions that use pci_resource_to_bus() and pci_bus_to_resource(). The replacements are equivalent except that they can apply host bridge window offsets when the arch has supplied them by using pci_add_resource_offset(). Each arch can convert to using pci_add_resource_offset() individually by removing its device resource fixups from pcibios_fixup_bus() and supplying ARCH_HAS_GENERIC_PCI_OFFSETS. ARCH_HAS_GENERIC_PCI_OFFSETS can be removed after all have converted. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-24PCI: add struct pci_host_bridge_window with CPU/bus address offsetBjorn Helgaas1-0/+9
Some PCI host bridges apply an address offset, so bus addresses on PCI are different from CPU addresses. This patch adds a way for architectures to tell the PCI core about this offset. For example: LIST_HEAD(resources); pci_add_resource_offset(&resources, host->io_space, host->io_offset); pci_add_resource_offset(&resources, host->mem_space, host->mem_offset); pci_scan_root_bus(parent, bus, ops, sysdata, &resources); Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-24PCI: add struct pci_host_bridge and a list of all bridges foundBjorn Helgaas1-0/+5
This adds a list of all PCI host bridges we find and a way to look up the host bridge from a pci_dev. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-24x86, efi: Allow basic init with mixed 32/64-bit efi/kernelOlof Johansson1-0/+45
Traditionally the kernel has refused to setup EFI at all if there's been a mismatch in 32/64-bit mode between EFI and the kernel. On some platforms that boot natively through EFI (Chrome OS being one), we still need to get at least some of the static data such as memory configuration out of EFI. Runtime services aren't as critical, and it's a significant amount of work to implement switching between the operating modes to call between kernel and firmware for thise cases. So I'm ignoring it for now. v5: * Fixed some printk strings based on feedback * Renamed 32/64-bit specific types to not have _ prefix * Fixed bug in printout of efi runtime disablement v4: * Some of the earlier cleanup was accidentally reverted by this patch, fixed. * Reworded some messages to not have to line wrap printk strings v3: * Reorganized to a series of patches to make it easier to review, and do some of the cleanups I had left out before. v2: * Added graceful error handling for 32-bit kernel that gets passed EFI data above 4GB. * Removed some warnings that were missed in first version. Signed-off-by: Olof Johansson <olof@lixom.net> Link: http://lkml.kernel.org/r/1329081869-20779-6-git-send-email-olof@lixom.net Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-02-24Merge branch 'fbdev-for-linus' into fbdev-nextFlorian Tobias Schandinat42-380/+177
2012-02-24ARM: 7339/1: amba/serial.h: Include types.h for resolving dependency of type ↵viresh kumar1-0/+2
bool serial.h uses bool, but its definition is missing, as it doesn't include types.h. Fix this by including types.h Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-02-24ipsec: be careful of non existing mac headersEric Dumazet1-0/+10
Niccolo Belli reported ipsec crashes in case we handle a frame without mac header (atm in his case) Before copying mac header, better make sure it is present. Bugzilla reference: https://bugzilla.kernel.org/show_bug.cgi?id=42809 Reported-by: Niccolò Belli <darkbasic@linuxsystems.it> Tested-by: Niccolò Belli <darkbasic@linuxsystems.it> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-24PCI: move pci_find_saved_cap out of linux/pci.hYinghai Lu1-19/+0
Only one user in driver/pci/pci.c, so we don't need to put it in global pci.h Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-24PCI: Add PCI_EXP_TYPE_PCIE_BRIDGE valueAnthony PERARD1-0/+1
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23Merge branch 'usb-3.3-rc4' into usb-nextGreg Kroah-Hartman5-0/+99
This is to pull in the xhci changes and the other fixes and device id updates that were done in Linus's tree. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-23Merge tag 'rpmsg-for-3.4' of ↵Arnd Bergmann4-0/+607
git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc into next/rpmsg * tag 'rpmsg-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc: remoteproc: s/big switch/lookup table/ remoteproc: bail out if firmware has different endianess remoteproc: don't use virtio's weak barriers rpmsg: rename virtqueue_add_buf_gfp to virtqueue_add_buf rpmsg: depend on EXPERIMENTAL remoteproc: depend on EXPERIMENTAL rpmsg: add Kconfig menu remoteproc: add Kconfig menu remoteproc: look for truncated firmware images remoteproc/omap: utilize module_platform_driver remoteproc: remove unused resource type remoteproc: avoid registering a virtio device if not supported remoteproc: do not require an iommu samples/rpmsg: add an rpmsg driver sample rpmsg: add virtio-based remote processor messaging bus remoteproc/omap: add a remoteproc driver for OMAP4 remoteproc: create rpmsg virtio device remoteproc: add debugfs entries remoteproc: add framework for controlling remote processors
2012-02-23OMAP1: pass LCD config with omapfb_set_lcd_config()Tomi Valkeinen1-0/+2
LCD config for old omapfb driver is passed with OMAP_TAG_LCD from board files or from the bootloader. In an effort to remove OMAP_TAG_LCD, this patch adds omapfb_set_lcd_config() function that the board files can call to set the LCD config. This has the drawback that configuration can no longer come from the bootloader. Of the boards supported by the kernel, this should only affect N770 which depends on the data from the bootloader. This patch adds an LCD config for N770 to its board files, but that is most probably broken. Fixing this would need information about the HW setup in N770 boards. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Acked-by: Tony Lindgren <tony@atomide.com>
2012-02-23OMAPFB: remove omapfb_set_platform_data()Tomi Valkeinen1-3/+0
omapfb_set_platform_data() is no longer used, so remove it. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Acked-by: Tony Lindgren <tony@atomide.com>
2012-02-23OMAPFB: Move old omapfb private structs to a private include fileTomi Valkeinen1-25/+0
include/linux/omapfb.h contains structs that are used only by the omapfb driver. Move the structs into drivers/video/omap/omapfb.h. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2012-02-23OMAPFB: remove mem info from platform_dataTomi Valkeinen1-1/+0
omapfb driver used platform_data to get fb memory areas and formats defined by the board file. This patch removes omapfb's (both old and new omapfb) use of the memory data in platform_data, because: - No board uses them currently - It's not board file's job to define things like amount of default framebuffer memory. These should come from the bootloader via command line parameters. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2012-02-23OMAPFB: remove early mem alloc from old omapfbTomi Valkeinen1-1/+0
arch/arm/plat-omap/fb.c contains code to alloc omapfb buffers at early boot time according to information given from the bootloader or board file. This code isn't currently used by any board, and is anyway something that the newer vram.c could handle. So remove the alloc code and in later patches make old omapfb driver use vram.c. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Acked-by: Tony Lindgren <tony@atomide.com>
2012-02-23OAMPFB: remove unused omapfb_set_ctrl_platform_data()Tomi Valkeinen1-2/+0
omapfb_set_ctrl_platform_data() is no longer used, so it can be removed. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Acked-by: Tony Lindgren <tony@atomide.com>
2012-02-23Merge branch 'nf' of git://1984.lsi.us.es/netDavid S. Miller1-2/+2
2012-02-23Merge branch 'for_3.4/gpio/runtime-pm-cleanup' of ↵Grant Likely23-355/+91
git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-omap-pm into gpio/next
2012-02-23Merge branch 'entry-macro-cleanup' of git://sources.calxeda.com/kernel/linux ↵Russell King10-8/+29
into for-armsoc
2012-02-23firewire: core: prefix log messages with card nameStefan Richter1-3/+0
Associate all log messages from firewire-core with the respective card because some people have more than one card. E.g. firewire_ohci 0000:04:00.0: added OHCI v1.10 device as card 0, 8 IR + 8 IT contexts, quirks 0x0 firewire_ohci 0000:05:00.0: added OHCI v1.10 device as card 1, 8 IR + 8 IT contexts, quirks 0x0 firewire_core: created device fw0: GUID 0814438400000389, S800 firewire_core: phy config: new root=ffc1, gap_count=5 firewire_core: created device fw1: GUID 0814438400000388, S800 firewire_core: created device fw2: GUID 0001d202e06800d1, S800 turns into firewire_ohci 0000:04:00.0: added OHCI v1.10 device as card 0, 8 IR + 8 IT contexts, quirks 0x0 firewire_ohci 0000:05:00.0: added OHCI v1.10 device as card 1, 8 IR + 8 IT contexts, quirks 0x0 firewire_core 0000:04:00.0: created device fw0: GUID 0814438400000389, S800 firewire_core 0000:04:00.0: phy config: new root=ffc1, gap_count=5 firewire_core 0000:05:00.0: created device fw1: GUID 0814438400000388, S800 firewire_core 0000:04:00.0: created device fw2: GUID 0001d202e06800d1, S800 This increases the module size slightly; to keep this in check, turn the former printk wrapper macros into functions. Their implementation is largely copied from driver core's dev_printk counterparts. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2012-02-23Merge tag 'usb-3.3-rc4' of ↵Linus Torvalds1-8/+2
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb USB bugfixes for 3.3-rc4 A number of new device ids, and a cleanup/fix for some of the option device ids that shouldn't have been added in the first place. There's also a few USB 3 fixes for problems that people have reported, and a usb-storage bugfix to round it out. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> * tag 'usb-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: USB: Added Kamstrup VID/PIDs to cp210x serial driver. USB: Serial: ti_usb_3410_5052: Add Abbot Diabetes Care cable id usb-storage: fix freezing of the scanning thread xhci: Fix encoding for HS bulk/control NAK rate. USB: Set hub depth after USB3 hub reset USB: Fix handoff when BIOS disables host PCI device. USB: option: cleanup zte 3g-dongle's pid in option.c USB: Don't fail USB3 probe on missing legacy PCI IRQ. xhci: Fix oops caused by more USB2 ports than USB3 ports. USB: Remove duplicate USB 3.0 hub feature #defines.
2012-02-23tracing/ring-buffer: Only have tracing_on disable tracing buffersSteven Rostedt1-0/+3
As the ring-buffer code is being used by other facilities in the kernel, having tracing_on file disable *all* buffers is not a desired affect. It should only disable the ftrace buffers that are being used. Move the code into the trace.c file and use the buffer disabling for tracing_on() and tracing_off(). This way only the ftrace buffers will be affected by them and other kernel utilities will not be confused to why their output suddenly stopped. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-02-22cfg80211: restructure AP/GO mode APIJohannes Berg1-15/+19
The AP/GO mode API isn't very clearly defined, it has "set beacon" and "new beacon" etc. Modify the API to the following: * start AP -- all settings * change beacon -- new beacon data * stop AP -- stop AP mode operation This also reflects in the nl80211 API, rename the commands there correspondingly (but keep the old names for compatibility.) Overall, this makes it much clearer what's going on in the API. Kalle developed the ath6kl changes, I created the rest of the patch. Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-02-22Merge tag 'nfs-for-3.3-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds1-1/+1
Bugfixes for the NFS client. Fix a nasty Oops in the NFSv4 getacl code, another source of infinite loops in the NFSv4 state recovery code, and a regression in NFSv4.1 session initialisation. Also deal with an NFSv4.1 memory leak. * tag 'nfs-for-3.3-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: NFSv4: fix server_scope memory leak NFSv4.1: Fix a NFSv4.1 session initialisation regression NFSv4: Ensure we throw out bad delegation stateids on NFS4ERR_BAD_STATEID NFSv4: Fix an Oops in the NFSv4 getacl code
2012-02-22remoteproc: s/big switch/lookup table/Ohad Ben-Cohen1-0/+7
A lookup table would be easier to extend, and the resulting code is a bit cleaner. Reported-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-02-22Merge branch 'lpc32xx/drivers' into next/driversArnd Bergmann21-27/+88
* lpc32xx/drivers: (566 commits) ARM: LPC32xx: ADC support for mach-lpc32xx Includes an update to Linux 3.3-rc4 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-02-22dmaengine/dw_dmac: Remove unused fields in struct dw_dma_slaveViresh Kumar1-38/+0
Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-02-22dmaengine/amba-pl08x: Take flow controller info from DMA_SLAVE_CONFIGViresh Kumar1-4/+4
Flow controller information is passed now from DMA_SLAVE_CONFIG option. This patch makes changes in pl08x driver to use device_fc from it instead of platform data. Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-02-22dmaengine: Add flow controller information to dma_slave_configViresh Kumar1-0/+5
Flow controller is programmable for few controllers and there are few intelligent peripherals like, Synopsys JPEG controller, that needs to be a flow controller of DMA transfers on dest side. For this, currently two drivers, pl08x and dw_dmac, support flow controller to be passed from platform to these drivers. Perhaps, this should be a part of struct dma_slave_config. This patch adds another field device_fc to this structure. User drivers must pass this as true if they want to be flow controller of certain transfers. Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-02-22sched: Make initial SCHED_RR timeslace DEF_TIMESLICEHiroshi Shimamoto2-1/+7
Current the initial SCHED_RR timeslice of init_task is HZ, which means 1s, and is not same as the default SCHED_RR timeslice DEF_TIMESLICE. Change that initial timeslice to the DEF_TIMESLICE. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> [ s/DEF_TIMESLICE/RR_TIMESLICE/g ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F3C9995.3010800@ct.jp.nec.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-22sys_poll: fix incorrect type for 'timeout' parameterLinus Torvalds1-1/+1
The 'poll()' system call timeout parameter is supposed to be 'int', not 'long'. Now, the reason this matters is that right now 32-bit compat mode is broken on at least x86-64, because the 32-bit code just calls 'sys_poll()' directly on x86-64, and the 32-bit argument will have been zero-extended, turning a signed 'int' into a large unsigned 'long' value. We could just introduce a 'compat_sys_poll()' function for this, and that may eventually be what we have to do, but since the actual standard poll() semantics is *supposed* to be 'int', and since at least on x86-64 glibc sign-extends the argument before invocing the system call (so nobody can actually use a 64-bit timeout value in user space _anyway_, even in 64-bit binaries), the simpler solution would seem to be to just fix the definition of the system call to match what it should have been from the very start. If it turns out that somebody somehow circumvents the user-level libc 64-bit sign extension and actually uses a large unsigned 64-bit timeout despite that not being how poll() is supposed to work, we will need to do the compat_sys_poll() approach. Reported-by: Thomas Meyer <thomas@m3y3r.de> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-22Merge branch 'for-davem' of ↵David S. Miller4-1/+169
git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next
2012-02-22rtnetlink: Fix problem with buffer allocationGreg Rose2-0/+4
Implement a new netlink attribute type IFLA_EXT_MASK. The mask is a 32 bit value that can be used to indicate to the kernel that certain extended ifinfo values are requested by the user application. At this time the only mask value defined is RTEXT_FILTER_VF to indicate that the user wants the ifinfo dump to send information about the VFs belonging to the interface. This patch fixes a bug in which certain applications do not have large enough buffers to accommodate the extra information returned by the kernel with large numbers of SR-IOV virtual functions. Those applications will not send the new netlink attribute with the interface info dump request netlink messages so they will not get unexpectedly large request buffers returned by the kernel. Modifies the rtnl_calcit function to traverse the list of net devices and compute the minimum buffer size that can hold the info dumps of all matching devices based upon the filter passed in via the new netlink attribute filter mask. If no filter mask is sent then the buffer allocation defaults to NLMSG_GOODSIZE. With this change it is possible to add yet to be defined netlink attributes to the dump request which should make it fairly extensible in the future. Signed-off-by: Greg Rose <gregory.v.rose@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-22of: Only compile OF_DYNAMIC on PowerPC pseries and iseriesGrant Likely1-8/+6
Only two architectures use the OF node reference counting and reclaim bits. There is no need to compile it for the rest of the PowerPC platforms or for any of the other architectures. This patch makes iseries and pseries select CONFIG_OF_DYNAMIC, and makes it default to off for everything else. It is still safe to turn on CONFIG_OF_DYNAMIC on all architectures, it just isn't necessary. v2: Also select OF_DYNAMIC for PPC_CHROMA and MPC885ADS as reported by Michael Meuling Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Jimi Xenidis <jimix@pobox.com> (for PPC_CHROMA bug fix) Cc: Rob Herring <rob.herring@calxeda.com>
2012-02-22Merge branch 'master' of ↵John W. Linville4-1/+169
git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem
2012-02-22sock: Introduce the SO_PEEK_OFF sock optionPavel Emelyanov1-0/+1
This one specifies where to start MSG_PEEK-ing queue data from. When set to negative value means that MSG_PEEK works as ususally -- peeks from the head of the queue always. When some bytes are peeked from queue and the peeking offset is non negative it is moved forward so that the next peek will return next portion of data. When non-peeking recvmsg occurs and the peeking offset is non negative is is moved backward so that the next peek will still peek the proper data (i.e. the one that would have been picked if there were no non peeking recv in between). The offset is set using per-proto opteration to let the protocol handle the locking issues and to check whether the peeking offset feature is supported by the protocol the socket belongs to. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-21skb: Add skb_peek_next helperPavel Emelyanov1-0/+18
Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-21datagram: Add offset argument to __skb_recv_datagramPavel Emelyanov1-1/+1
This one is only considered for MSG_PEEK flag and the value pointed by it specifies where to start peeking bytes from. If the offset happens to point into the middle of the returned skb, the offset within this skb is put back to this very argument. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-21Merge tag 'topic/introspection' of ↵Mark Brown1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into HEAD New interfaces to allow other subsystems to gather information about the regmap, allowing them to build further subsystem specific generic features on top of the regmap. Merged into ASoC in order to allow us to implement SND_SOC_BYTES_MASK() controls which need to know the word size of the underlying registers.
2012-02-21percpu: use raw_local_irq_* in _this_cpu opMing Lei1-10/+10
It doesn't make sense to trace irq off or do irq flags lock proving inside 'this_cpu' operations, so replace local_irq_* with raw_local_irq_* in 'this_cpu' op. Also the patch fixes onelockdep warning[1] by the replacement, see below: In commit: 933393f58fef9963eac61db8093689544e29a600(percpu: Remove irqsafe_cpu_xxx variants), local_irq_save/restore(flags) are added inside this_cpu_inc operation, so that trace_hardirqs_off_caller will be called by trace_hardirqs_on_caller directly because __debug_atomic_inc is implemented as this_cpu_inc, which may trigger the lockdep warning[1], for example in the below ARM scenary: kernel_thread_helper /*irq disabled*/ ->trace_hardirqs_on_caller /*hardirqs_enabled was set*/ ->trace_hardirqs_off_caller /*hardirqs_enabled cleared*/ __this_cpu_add(redundant_hardirqs_on) ->trace_hardirqs_off_caller /*irq disabled, so call here*/ The 'unannotated irqs-on' warning will be triggered somewhere because irq is just enabled after the irq trace in kernel_thread_helper. [1], [ 0.162841] ------------[ cut here ]------------ [ 0.167694] WARNING: at kernel/lockdep.c:3493 check_flags+0xc0/0x1d0() [ 0.174468] Modules linked in: [ 0.177703] Backtrace: [ 0.180328] [<c00171f0>] (dump_backtrace+0x0/0x110) from [<c0412320>] (dump_stack+0x18/0x1c) [ 0.189086] r6:c051f778 r5:00000da5 r4:00000000 r3:60000093 [ 0.195007] [<c0412308>] (dump_stack+0x0/0x1c) from [<c00410e8>] (warn_slowpath_common+0x54/0x6c) [ 0.204223] [<c0041094>] (warn_slowpath_common+0x0/0x6c) from [<c0041124>] (warn_slowpath_null+0x24/0x2c) [ 0.214111] r8:00000000 r7:00000000 r6:ee069598 r5:60000013 r4:ee082000 [ 0.220825] r3:00000009 [ 0.223693] [<c0041100>] (warn_slowpath_null+0x0/0x2c) from [<c0088f38>] (check_flags+0xc0/0x1d0) [ 0.232910] [<c0088e78>] (check_flags+0x0/0x1d0) from [<c008d348>] (lock_acquire+0x4c/0x11c) [ 0.241668] [<c008d2fc>] (lock_acquire+0x0/0x11c) from [<c0415aa4>] (_raw_spin_lock+0x3c/0x74) [ 0.250610] [<c0415a68>] (_raw_spin_lock+0x0/0x74) from [<c010a844>] (set_task_comm+0x20/0xc0) [ 0.259521] r6:ee069588 r5:ee0691c0 r4:ee082000 [ 0.264404] [<c010a824>] (set_task_comm+0x0/0xc0) from [<c0060780>] (kthreadd+0x28/0x108) [ 0.272857] r8:00000000 r7:00000013 r6:c0044a08 r5:ee0691c0 r4:ee082000 [ 0.279571] r3:ee083fe0 [ 0.282470] [<c0060758>] (kthreadd+0x0/0x108) from [<c0044a08>] (do_exit+0x0/0x6dc) [ 0.290405] r5:c0060758 r4:00000000 [ 0.294189] ---[ end trace 1b75b31a2719ed1c ]--- [ 0.299041] possible reason: unannotated irqs-on. [ 0.303955] irq event stamp: 5 [ 0.307159] hardirqs last enabled at (4): [<c001331c>] no_work_pending+0x8/0x2c [ 0.314880] hardirqs last disabled at (5): [<c0089b08>] trace_hardirqs_on_caller+0x60/0x26c [ 0.323547] softirqs last enabled at (0): [<c003f754>] copy_process+0x33c/0xef4 [ 0.331207] softirqs last disabled at (0): [< (null)>] (null) [ 0.337585] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000 Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2012-02-21rcu: Add RCU_NONIDLE() for idle-loop RCU read-side critical sectionsPaul E. McKenney1-0/+27
RCU, RCU-bh, and RCU-sched read-side critical sections are forbidden in the inner idle loop, that is, between the rcu_idle_enter() and the rcu_idle_exit() -- RCU will happily ignore any such read-side critical sections. However, things like powertop need tracepoints in the inner idle loop. This commit therefore provides an RCU_NONIDLE() macro that can be used to wrap code in the idle loop that requires RCU read-side critical sections. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
2012-02-21rcu: Convert WARN_ON_ONCE() in rcu_lock_acquire() to lockdepHeiko Carstens2-2/+16
The WARN_ON_ONCE() in rcu_lock_acquire() results in infinite recursion on S390, and also doesn't print very much information. Remove this. Updated patch to add lockdep-RCU assertions to RCU's read-side primitives. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-02-21rcu: Call out dangers of expedited RCU primitivesPaul E. McKenney1-0/+16
The expedited RCU primitives can be quite useful, but they have some high costs as well. This commit updates and creates docbook comments calling out the costs, and updates the RCU documentation as well. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-02-21rcu: Check for illegal use of RCU from offlined CPUsPaul E. McKenney2-4/+26
Although it is legal to use RCU during early boot, it is anything but legal to use RCU at runtime from an offlined CPU. After all, RCU explicitly ignores offlined CPUs. This commit therefore adds checks for runtime use of RCU from offlined CPUs. These checks are not perfect, in particular, they can be subverted through use of things like rcu_dereference_raw(). Note that it is not possible to put checks in rcu_read_lock() and friends due to the fact that these primitives are used in code that might be used under either RCU or lock-based protection, which means that checking rcu_read_lock() gets you fat piles of false positives. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-02-21rcu: Note that rcu_access_pointer() can be used for teardownPaul E. McKenney1-0/+7
There is no convenient expression for rcu_deference_protected() when it is used in tearing down multilinked structures following a grace period. For example, suppose that an element containing an RCU-protected pointer to a second element is removed from an enclosing RCU-protected data structure, then the write-side lock is released, and finally synchronize_rcu() is invoked to wait for a grace period. Then it is necessary to traverse the pointer in order to free up the second element. But we are not in an RCU read-side critical section and we are holding no locks, so the usual rcu_dereference_check() and rcu_dereference_protected() primitives are not appropriate. Neither is rcu_dereference_raw(), as it is intended for use in data structures where the user defines the locking design (for example, list_head). So this responsibility is added to rcu_access_pointer()'s list, and this commit updates rcu_assign_pointer()'s header comment accordingly. Suggested-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: David Howells <dhowells@redhat.com>
2012-02-21rcu: Make rcu_sleep_check() also check rcu_lock_mapPaul E. McKenney1-0/+14
Although it is OK to be preempted in an RCU read-side critical section for TREE_PREEMPT_RCU, it is definitely not OK to be preempted, block, or might_sleep() within an RCU read-side critical section for TREE_RCU. Unfortunately, rcu_might_sleep() currently only checks for RCU-bh and RCU-sched read-side critical sections. This commit therefore makes rcu_might_sleep() check for RCU read-side critical sections, but only in TREE_RCU builds. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-02-21rcu: Simplify unboosting checksPaul E. McKenney1-2/+1
This is a port of commit #82e78d80 from TREE_PREEMPT_RCU to TINY_PREEMPT_RCU. This commit uses the fact that current->rcu_boost_mutex is set any time that the RCU_READ_UNLOCK_BOOSTED flag is set in the current->rcu_read_unlock_special bitmask. This allows tests of the bit to be changed to tests of the pointer, which in turn allows the RCU_READ_UNLOCK_BOOSTED flag to be eliminated. Please note that the check of current->rcu_read_unlock_special need not change because any time that RCU_READ_UNLOCK_BOOSTED was set, so was RCU_READ_UNLOCK_BLOCKED. Therefore, __rcu_read_unlock() can continue testing current->rcu_read_unlock_special for non-zero, as before. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>