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* Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds2012-01-061-2/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) cpu: Export cpu_up() rcu: Apply ACCESS_ONCE() to rcu_boost() return value Revert "rcu: Permit rt_mutex_unlock() with irqs disabled" docs: Additional LWN links to RCU API rcu: Augment rcu_batch_end tracing for idle and callback state rcu: Add rcutorture tests for srcu_read_lock_raw() rcu: Make rcutorture test for hotpluggability before offlining CPUs driver-core/cpu: Expose hotpluggability to the rest of the kernel rcu: Remove redundant rcu_cpu_stall_suppress declaration rcu: Adaptive dyntick-idle preparation rcu: Keep invoking callbacks if CPU otherwise idle rcu: Irq nesting is always 0 on rcu_enter_idle_common rcu: Don't check irq nesting from rcu idle entry/exit rcu: Permit dyntick-idle with callbacks pending rcu: Document same-context read-side constraints rcu: Identify dyntick-idle CPUs on first force_quiescent_state() pass rcu: Remove dynticks false positives and RCU failures rcu: Reduce latency of rcu_prepare_for_idle() rcu: Eliminate RCU_FAST_NO_HZ grace-period hang rcu: Avoid needlessly IPIing CPUs at GP end ...
| * nohz: Remove tick_nohz_idle_enter_norcu() / tick_nohz_idle_exit_norcu()Frederic Weisbecker2011-12-111-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Those two APIs were provided to optimize the calls of tick_nohz_idle_enter() and rcu_idle_enter() into a single irq disabled section. This way no interrupt happening in-between would needlessly process any RCU job. Now we are talking about an optimization for which benefits have yet to be measured. Let's start simple and completely decouple idle rcu and dyntick idle logics to simplify. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * nohz: Allow rcu extended quiescent state handling seperately from tick stopFrederic Weisbecker2011-12-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is assumed that rcu won't be used once we switch to tickless mode and until we restart the tick. However this is not always true, as in x86-64 where we dereference the idle notifiers after the tick is stopped. To prepare for fixing this, add two new APIs: tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu(). If no use of RCU is made in the idle loop between tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch must instead call the new *_norcu() version such that the arch doesn't need to call rcu_idle_enter() and rcu_idle_exit(). Otherwise the arch must call tick_nohz_enter_idle() and tick_nohz_exit_idle() and also call explicitly: - rcu_idle_enter() after its last use of RCU before the CPU is put to sleep. - rcu_idle_exit() before the first use of RCU after the CPU is woken up. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * nohz: Separate out irq exit and idle loop dyntick logicFrederic Weisbecker2011-12-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tick_nohz_stop_sched_tick() function, which tries to delay the next timer tick as long as possible, can be called from two places: - From the idle loop to start the dytick idle mode - From interrupt exit if we have interrupted the dyntick idle mode, so that we reprogram the next tick event in case the irq changed some internal state that requires this action. There are only few minor differences between both that are handled by that function, driven by the ts->inidle cpu variable and the inidle parameter. The whole guarantees that we only update the dyntick mode on irq exit if we actually interrupted the dyntick idle mode, and that we enter in RCU extended quiescent state from idle loop entry only. Split this function into: - tick_nohz_idle_enter(), which sets ts->inidle to 1, enters dynticks idle mode unconditionally if it can, and enters into RCU extended quiescent state. - tick_nohz_irq_exit() which only updates the dynticks idle mode when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called). To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed into tick_nohz_idle_exit(). This simplifies the code and micro-optimize the irq exit path (no need for local_irq_save there). This also prepares for the split between dynticks and rcu extended quiescent state logics. We'll need this split to further fix illegal uses of RCU in extended quiescent states in the idle loop. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* | memblock: s/memblock_analyze()/memblock_allow_resize()/ and update usersTejun Heo2011-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only function of memblock_analyze() is now allowing resize of memblock region arrays. Rename it to memblock_allow_resize() and update its users. * The following users remain the same other than renaming. arm/mm/init.c::arm_memblock_init() microblaze/kernel/prom.c::early_init_devtree() powerpc/kernel/prom.c::early_init_devtree() openrisc/kernel/prom.c::early_init_devtree() sh/mm/init.c::paging_init() sparc/mm/init_64.c::paging_init() unicore32/mm/init.c::uc32_memblock_init() * In the following users, analyze was used to update total size which is no longer necessary. powerpc/kernel/machine_kexec.c::reserve_crashkernel() powerpc/kernel/prom.c::early_init_devtree() powerpc/mm/init_32.c::MMU_init() powerpc/mm/tlb_nohash.c::__early_init_mmu() powerpc/platforms/ps3/mm.c::ps3_mm_add_memory() powerpc/platforms/embedded6xx/wii.c::wii_memory_fixups() sh/kernel/machine_kexec.c::reserve_crashkernel() * x86/kernel/e820.c::memblock_x86_fill() was directly setting memblock_can_resize before populating memblock and calling analyze afterwards. Call memblock_allow_resize() before start populating. memblock_can_resize is now static inside memblock.c. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: "H. Peter Anvin" <hpa@zytor.com>
* | memblock: Kill memblock_init()Tejun Heo2011-12-081-1/+0
|/ | | | | | | | | | | | | | | | | | | | | memblock_init() initializes arrays for regions and memblock itself; however, all these can be done with struct initializers and memblock_init() can be removed. This patch kills memblock_init() and initializes memblock with struct initializer. The only difference is that the first dummy entries don't have .nid set to MAX_NUMNODES initially. This doesn't cause any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: "H. Peter Anvin" <hpa@zytor.com>
* Add missing DMA opsJonas Bonn2011-09-111-1/+27
| | | | | | | | | | | For the initial architecture submission, not all of the DMA ops were implemented. This patch adds the *map_page and *map_sg variants of the DMA mapping ops. This patch is currently of interest mainly to some drivers that haven't been submitted upstream yet. Signed-off-by: Jonas Bonn <jonas@southpole.se>
* openrisc: don't use pt_regs in struct sigcontextJonas Bonn2011-09-051-18/+11
| | | | | | | | | | | | | | | | | As it was decided not to export struct pt_regs to userspace, struct sigcontext shouldn't be using it either. The pt_regs struct for OpenRISC is kernel internal and the layout of the registers may change in the future. The struct user_regs_struct is what is guaranteed to remain stable, so struct sigcontext may use that instead. This patch removes the usage of struct pt_regs in struct sigcontext and makes according changes in signal.c to get the register layout right. The usp field is removed from the sigcontext structure as this information is already contained in the user_regs_struct. Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Emilio Cota <cota@braap.org>
* OpenRISC: MiscellaneousJonas Bonn2011-07-222-0/+116
| | | | | | | | Adds README file, TODO list, and a couple of other pieces that didn't seem to fit into any other patch. Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: HeadersJonas Bonn2011-07-221-0/+12
| | | | | Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: TrapsJonas Bonn2011-07-221-0/+366
| | | | | Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: Module supportJonas Bonn2011-07-221-0/+72
| | | | | Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: Scheduling/Process managementJonas Bonn2011-07-221-0/+311
| | | | | Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: Idle/Power managementJonas Bonn2011-07-221-0/+77
| | | | | | | Minimal functionality... Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: System callsJonas Bonn2011-07-222-0/+85
| | | | | | | | | | | | | | The OpenRISC Linux kernel conforms to the "generic" syscall interface which contains only the reduced set of syscalls deemed necessary for new architectures. Unfortunately, the uClibc port for OpenRISC does not fully support this reduced set; as such, an additional patch available out-of-tree needs to be applied to the kernel in order to use the current uClibc. This is just a temporary measure until the libc port can be straightened out; it is likely that OpenRISC will make the transition to glibc shortly where the generic syscall interface is better supported. Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: IRQJonas Bonn2011-07-221-0/+172
| | | | | | | | This patch adds support for the OpenRISC PIC. Signed-off-by: Jonas Bonn <jonas@southpole.se> Cc: tglx@linutronix.de Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: TimekeepingJonas Bonn2011-07-221-0/+181
| | | | | | | | | | Implements support for the OpenRISC timer which is a 28 bit cycle counter that can be read out of a special purpose register. This counter is used as a both a clock event and clocksource device. Signed-off-by: Jonas Bonn <jonas@southpole.se> Cc: tglx@linutronix.de Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: DMAJonas Bonn2011-07-221-0/+191
| | | | | | | | Simple DMA implementation. Allows for allocation of coherent memory (simply uncached) for DMA operations. Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: PTraceJonas Bonn2011-07-221-0/+211
| | | | | | | | | | | | | This patch implements minimal PTrace support. The pt_regs structure is not exported to userspace for OpenRISC; rather, the GETREGSET mechanism is intended to be used and the registers, as such, exported in the core dump format which is ABI stable. This is in line with what is intended for new architectures as of 2.6.34 and has the advantage of permitting the layout of the registers on the kernel stack (as per pt_regs) to be freely modified. Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: Build infrastructureJonas Bonn2011-07-222-0/+129
| | | | | Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: Signal handlingJonas Bonn2011-07-221-0/+396
| | | | | Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: Device treeJonas Bonn2011-07-221-0/+108
| | | | | | | | | | | | | | | The OpenRISC architecture uses the device tree infrastructure for the platform description. This is currently limited to having a device tree built into the kernel, but work is underway within the OpenRISC project to define how this device tree blob should be passed into the kernel from an external resource. Patch contains a single example DTS file to go with the defconfig for or1ksim. Signed-off-by: Jonas Bonn <jonas@southpole.se> Cc: devicetree-discuss@lists.ozlabs.org Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* OpenRISC: Boot codeJonas Bonn2011-07-224-0/+3157
Architecture code and early setup routines for booting Linux. Signed-off-by: Jonas Bonn <jonas@southpole.se> Reviewed-by: Arnd Bergmann <arnd@arndb.de>