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2012-07-31ARM: 7480/1: only call smp_send_stop() on SMPJavier Martinez Canillas
On reboot or poweroff (machine_shutdown()) a call to smp_send_stop() is made (to stop the others CPU's) when CONFIG_SMP=y. arch/arm/kernel/process.c: void machine_shutdown(void) { #ifdef CONFIG_SMP smp_send_stop(); #endif } smp_send_stop() calls the function pointer smp_cross_call(), which is set on the smp_init_cpus() function for OMAP processors. arch/arm/mach-omap2/omap-smp.c: void __init smp_init_cpus(void) { ... set_smp_cross_call(gic_raise_softirq); ... } But the ARM setup_arch() function only calls smp_init_cpus() if CONFIG_SMP=y && is_smp(). arm/kernel/setup.c: void __init setup_arch(char **cmdline_p) { ... #ifdef CONFIG_SMP if (is_smp()) smp_init_cpus(); #endif ... } Newer OMAP CPU's are SMP machines so omap2plus_defconfig sets CONFIG_SMP=y. Unfortunately on an OMAP UP machine is_smp() returns false and smp_init_cpus() is never called and the smp_cross_call() function remains NULL. If the machine is rebooted or powered off, smp_send_stop() will be called (since CONFIG_SMP=y) leading to the following error: [ 42.815551] Restarting system. [ 42.819030] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 42.827667] pgd = d7a74000 [ 42.830566] [00000000] *pgd=96ce7831, *pte=00000000, *ppte=00000000 [ 42.837249] Internal error: Oops: 80000007 [#1] SMP ARM [ 42.842773] Modules linked in: [ 42.846008] CPU: 0 Not tainted (3.5.0-rc3-next-20120622-00002-g62e87ba-dirty #44) [ 42.854278] PC is at 0x0 [ 42.856994] LR is at smp_send_stop+0x4c/0xe4 [ 42.861511] pc : [<00000000>] lr : [<c00183a4>] psr: 60000013 [ 42.861511] sp : d6c85e70 ip : 00000000 fp : 00000000 [ 42.873626] r10: 00000000 r9 : d6c84000 r8 : 00000002 [ 42.879150] r7 : c07235a0 r6 : c06dd2d0 r5 : 000f4241 r4 : d6c85e74 [ 42.886047] r3 : 00000000 r2 : 00000000 r1 : 00000006 r0 : d6c85e74 [ 42.892944] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 42.900482] Control: 10c5387d Table: 97a74019 DAC: 00000015 [ 42.906555] Process reboot (pid: 1166, stack limit = 0xd6c842f8) [ 42.912902] Stack: (0xd6c85e70 to 0xd6c86000) [ 42.917510] 5e60: c07235a0 00000000 00000000 d6c84000 [ 42.926177] 5e80: 01234567 c00143d0 4321fedc c00511bc d6c85ebc 00000168 00000460 00000000 [ 42.934814] 5ea0: c1017950 a0000013 c1017900 d8014390 d7ec3858 c0498e48 c1017950 00000000 [ 42.943481] 5ec0: d6ddde10 d6c85f78 00000003 00000000 d6ddde10 d6c84000 00000000 00000000 [ 42.952117] 5ee0: 00000002 00000000 00000000 c0088c88 00000002 00000000 00000000 c00f4b90 [ 42.960784] 5f00: 00000000 d6c85ebc d8014390 d7e311c8 60000013 00000103 00000002 d6c84000 [ 42.969421] 5f20: c00f3274 d6e00a00 00000001 60000013 d6c84000 00000000 00000000 c00895d4 [ 42.978057] 5f40: 00000002 d8007c80 d781f000 c00f6150 d8010cc0 c00f3274 d781f000 d6c84000 [ 42.986694] 5f60: c0013020 d6e00a00 00000001 20000010 0001257c ef000000 00000000 c00895d4 [ 42.995361] 5f80: 00000002 00000001 00000003 00000000 00000001 00000003 00000000 00000058 [ 43.003997] 5fa0: c00130c8 c0012f00 00000001 00000003 fee1dead 28121969 01234567 00000002 [ 43.012634] 5fc0: 00000001 00000003 00000000 00000058 00012584 0001257c 00000001 00000000 [ 43.021270] 5fe0: 000124bc bec5cc6c 00008f9c 4a2f7c40 20000010 fee1dead 00000000 00000000 [ 43.029968] [<c00183a4>] (smp_send_stop+0x4c/0xe4) from [<c00143d0>] (machine_restart+0xc/0x4c) [ 43.039154] [<c00143d0>] (machine_restart+0xc/0x4c) from [<c00511bc>] (sys_reboot+0x144/0x1f0) [ 43.048278] [<c00511bc>] (sys_reboot+0x144/0x1f0) from [<c0012f00>] (ret_fast_syscall+0x0/0x3c) [ 43.057464] Code: bad PC value [ 43.060760] ---[ end trace c3988d1dd0b8f0fb ]--- Add a check so smp_cross_call() is only called when there is more than one CPU on-line. Cc: <stable@vger.kernel.org> Signed-off-by: Javier Martinez Canillas <javier at dowhile0.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09ARM: 7457/1: smp: Fix suspicious RCU originating from cpu_die()Stephen Boyd
While running hotplug tests I ran into this RCU splat =============================== [ INFO: suspicious RCU usage. ] 3.4.0 #3275 Tainted: G W ------------------------------- include/linux/rcupdate.h:729 rcu_read_lock() used illegally while idle! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 4 locks held by swapper/2/0: #0: ((cpu_died).wait.lock){......}, at: [<c00ab128>] complete+0x1c/0x5c #1: (&p->pi_lock){-.-.-.}, at: [<c00b275c>] try_to_wake_up+0x2c/0x388 #2: (&rq->lock){-.-.-.}, at: [<c00b2860>] try_to_wake_up+0x130/0x388 #3: (rcu_read_lock){.+.+..}, at: [<c00abe5c>] cpuacct_charge+0x28/0x1f4 stack backtrace: [<c001521c>] (unwind_backtrace+0x0/0x12c) from [<c00abec8>] (cpuacct_charge+0x94/0x1f4) [<c00abec8>] (cpuacct_charge+0x94/0x1f4) from [<c00b395c>] (update_curr+0x24c/0x2c8) [<c00b395c>] (update_curr+0x24c/0x2c8) from [<c00b59c4>] (enqueue_task_fair+0x50/0x194) [<c00b59c4>] (enqueue_task_fair+0x50/0x194) from [<c00afea4>] (enqueue_task+0x30/0x34) [<c00afea4>] (enqueue_task+0x30/0x34) from [<c00b0908>] (ttwu_activate+0x14/0x38) [<c00b0908>] (ttwu_activate+0x14/0x38) from [<c00b28a8>] (try_to_wake_up+0x178/0x388) [<c00b28a8>] (try_to_wake_up+0x178/0x388) from [<c00a82a0>] (__wake_up_common+0x34/0x78) [<c00a82a0>] (__wake_up_common+0x34/0x78) from [<c00ab154>] (complete+0x48/0x5c) [<c00ab154>] (complete+0x48/0x5c) from [<c07db7cc>] (cpu_die+0x2c/0x58) [<c07db7cc>] (cpu_die+0x2c/0x58) from [<c000f954>] (cpu_idle+0x64/0xfc) [<c000f954>] (cpu_idle+0x64/0xfc) from [<80208160>] (0x80208160) When a cpu is marked offline during its idle thread it calls cpu_die() during an RCU idle period. cpu_die() calls complete() to notify the killing process that the cpu has died. complete() calls into the scheduler code and eventually grabs an RCU read lock in cpuacct_charge(). Mark complete() as RCU_NONIDLE so that RCU pays attention to this CPU for the duration of the complete() function even though it's in idle. Suggested-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-06-01arm: use clear_tasks_mm_cpumask()Anton Vorontsov
Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has this issue fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-22Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp hotplug cleanups from Thomas Gleixner: "This series is merily a cleanup of code copied around in arch/* and not changing any of the real cpu hotplug horrors yet. I wish I'd had something more substantial for 3.5, but I underestimated the lurking horror..." Fix up trivial conflicts in arch/{arm,sparc,x86}/Kconfig and arch/sparc/include/asm/thread_info_32.h * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits) um: Remove leftover declaration of alloc_task_struct_node() task_allocator: Use config switches instead of magic defines sparc: Use common threadinfo allocator score: Use common threadinfo allocator sh-use-common-threadinfo-allocator mn10300: Use common threadinfo allocator powerpc: Use common threadinfo allocator mips: Use common threadinfo allocator hexagon: Use common threadinfo allocator m32r: Use common threadinfo allocator frv: Use common threadinfo allocator cris: Use common threadinfo allocator x86: Use common threadinfo allocator c6x: Use common threadinfo allocator fork: Provide kmemcache based thread_info allocator tile: Use common threadinfo allocator fork: Provide weak arch_release_[task_struct|thread_info] functions fork: Move thread info gfp flags to header fork: Remove the weak insanity sh: Remove cpu_idle_wait() ...
2012-05-21Merge branches 'amba', 'devel-stable', 'fixes', 'mach-types', 'mmci', 'pci' ↵Russell King
and 'versatile' into for-linus
2012-05-08Merge branch 'smp/threadalloc' into smp/hotplugThomas Gleixner
Reason: Pull in the separate branch which was created so arch/tile can base further work on it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-05-06ARM: 7414/1: SMP: prevent use of the console when using idmap_pgdColin Cross
Commit 4e8ee7de227e3ab9a72040b448ad728c5428a042 (ARM: SMP: use idmap_pgd for mapping MMU enable during secondary booting) switched secondary boot to use idmap_pgd, which is initialized during early_initcall, instead of a page table initialized during __cpu_up. This causes idmap_pgd to contain the static mappings but be missing all dynamic mappings. If a console is registered that creates a dynamic mapping, the printk in secondary_start_kernel will trigger a data abort on the missing mapping before the exception handlers have been initialized, leading to a hang. Initial boot is not affected because no consoles have been registered, and resume is usually not affected because the offending console is suspended. Onlining a cpu with hotplug triggers the problem. A workaround is to the printk in secondary_start_kernel until after the page tables have been switched back to init_mm. Cc: <stable@vger.kernel.org> Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-04-28ARM: 7405/1: kexec: call platform_cpu_kill on the killer rather than the victimWill Deacon
When performing a kexec on an SMP system, the secondary cores are stopped by calling machine_shutdown(), which in turn issues IPIs to offline the other CPUs. Unfortunately, this isn't enough to reboot the cores into a new kernel (since they are just executing a cpu_relax loop somewhere in memory) so we make use of platform_cpu_kill, part of the CPU hotplug implementation, to place the cores somewhere safe. This function expects to be called on the killing CPU for each core that it takes out. This patch moves the platform_cpu_kill callback out of the IPI handler and into smp_send_stop, therefore ensuring that it executes on the killing CPU rather than on the victim, matching what the hotplug code requires. Cc: stable@vger.kernel.org Reported-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-04-27ARM: local timers: reserve local_timer_register() to SMPMarc Zyngier
When running an SMP_ON_UP enabled kernel on UP, or with nosmp passed to the kernel, we want to be able to detect that a local timer is not going to be used (local timers are only used on SMP platforms), so we could register it as a global timer instead. Return -ENXIO when the above case is detected. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-04-26arm: Use generic idle thread allocationThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Tested-by: Frank Rowand <frank.rowand@am.sony.com> Link: http://lkml.kernel.org/r/20120420124557.448826362@linutronix.de
2012-04-26smp: Add task_struct argument to __cpu_up()Thomas Gleixner
Preparatory patch to make the idle thread allocation for secondary cpus generic. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Richard Weinberger <richard@nod.at> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20120420124556.964170564@linutronix.de
2012-04-02Merge tag 'for-linus' of git://github.com/rustyrussell/linuxLinus Torvalds
Pull cpumask cleanups from Rusty Russell: "(Somehow forgot to send this out; it's been sitting in linux-next, and if you don't want it, it can sit there another cycle)" I'm a sucker for things that actually delete lines of code. Fix up trivial conflict in arch/arm/kernel/kprobes.c, where Rusty fixed a user of &cpu_online_map to be cpu_online_mask, but that code got deleted by commit b21d55e98ac2 ("ARM: 7332/1: extract out code patch function from kprobes"). * tag 'for-linus' of git://github.com/rustyrussell/linux: cpumask: remove old cpu_*_map. documentation: remove references to cpu_*_map. drivers/cpufreq/db8500-cpufreq: remove references to cpu_*_map. remove references to cpu_*_map in arch/
2012-03-29Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds
Pull more ARM updates from Russell King. This got a fair number of conflicts with the <asm/system.h> split, but also with some other sparse-irq and header file include cleanups. They all looked pretty trivial, though. * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits) ARM: fix Kconfig warning for HAVE_BPF_JIT ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds ARM: 7349/1: integrator: convert to sparse irqs ARM: 7259/3: net: JIT compiler for packet filters ARM: 7334/1: add jump label support ARM: 7333/2: jump label: detect %c support for ARM ARM: 7338/1: add support for early console output via semihosting ARM: use set_current_blocked() and block_sigmask() ARM: exec: remove redundant set_fs(USER_DS) ARM: 7332/1: extract out code patch function from kprobes ARM: 7331/1: extract out insn generation code from ftrace ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format ARM: 7351/1: ftrace: remove useless memory checks ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path ARM: Versatile Express: add NO_IOPORT ARM: get rid of asm/irq.h in asm/prom.h ARM: 7319/1: Print debug info for SIGBUS in user faults ARM: 7318/1: gic: refactor irq_start assignment ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop ARM: 7315/1: perf: add support for the Cortex-A7 PMU ...
2012-03-29remove references to cpu_*_map in arch/Rusty Russell
This has been obsolescent for a while; time for the final push. In adjacent context, replaced old cpus_* with cpumask_*. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: David S. Miller <davem@davemloft.net> (arch/sparc) Acked-by: Chris Metcalf <cmetcalf@tilera.com> (arch/tile) Cc: user-mode-linux-devel@lists.sourceforge.net Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: Richard Kuo <rkuo@codeaurora.org> Cc: linux-hexagon@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: sparclinux@vger.kernel.org
2012-03-27Merge tag 'timer' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-socLinus Torvalds
Pull "ARM: timer cleanup work" from Arnd Bergmann: "These are split out from the generic soc and driver updates because there was a lot of conflicting work by multiple people. Marc Zyngier worked on simplifying the "localtimer" interfaces, and some of the platforms are touching the same code as they move to device tree based booting. Signed-off-by: Arnd Bergmann <arnd@arndb.de>" * tag 'timer' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (61 commits) ARM: tegra: select USB_ULPI if USB is selected arm/tegra: pcie: fix return value of function ARM: ux500: fix compilation after local timer rework ARM: shmobile: remove additional __io() macro use ARM: local timers: make the runtime registration interface mandatory ARM: local timers: convert MSM to runtime registration interface ARM: local timers: convert exynos to runtime registration interface ARM: smp_twd: remove old local timer interface ARM: imx6q: convert to twd_local_timer_register() interface ARM: highbank: convert to twd_local_timer_register() interface ARM: ux500: convert to twd_local_timer_register() interface ARM: shmobile: convert to twd_local_timer_register() interface ARM: tegra: convert to twd_local_timer_register() interface ARM: plat-versatile: convert to twd_local_timer_register() interface ARM: OMAP4: convert to twd_local_timer_register() interface ARM: smp_twd: add device tree support ARM: smp_twd: add runtime registration support ARM: local timers: introduce a new registration interface ARM: smp_twd: make local_timer_stop a symbol instead of a #define ARM: mach-shmobile: default to no earlytimer ...
2012-03-24ARM: SMP: use a timing out completion for cpu hotplugRussell King
Rather than open-coding the jiffy-based wait, and polling for the secondary CPU to come online, use a completion instead. This removes the need to poll, instead we will be notified when the secondary CPU has initialized. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-13ARM: local timers: make the runtime registration interface mandatoryMarc Zyngier
Remove all traces of the compile-time local timer interface, and make the runtime selection mandatory. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-03-13ARM: local timers: introduce a new registration interfaceMarc Zyngier
In order to switch to a runtime selectable local timer, add a registration interface that timer drivers can use to register to the core. local_timer_setup() and local_timer_stop() are made weak symbols in order not to break existing setups. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-03-12sched: Cleanup cpu_active madnessPeter Zijlstra
Stepan found: CPU0 CPUn _cpu_up() __cpu_up() boostrap() notify_cpu_starting() set_cpu_online() while (!cpu_active()) cpu_relax() <PREEMPT-out> smp_call_function(.wait=1) /* we find cpu_online() is true */ arch_send_call_function_ipi_mask() /* wait-forever-more */ <PREEMPT-in> local_irq_enable() cpu_notify(CPU_ONLINE) sched_cpu_active() set_cpu_active() Now the purpose of cpu_active is mostly with bringing down a cpu, where we mark it !active to avoid the load-balancer from moving tasks to it while we tear down the cpu. This is required because we only update the sched_domain tree after we brought the cpu-down. And this is needed so that some tasks can still run while we bring it down, we just don't want new tasks to appear. On cpu-up however the sched_domain tree doesn't yet include the new cpu, so its invisible to the load-balancer, regardless of the active state. So instead of setting the active state after we boot the new cpu (and consequently having to wait for it before enabling interrupts) set the cpu active before we set it online and avoid the whole mess. Reported-by: Stepan Moskovchenko <stepanm@codeaurora.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1323965362.18942.71.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-23ARM: 7293/1: logical_cpu_map: decouple CPU mapping from SMPWill Deacon
It turns out that the logical CPU mapping is useful even when !CONFIG_SMP for manipulation of devices like interrupt and power controllers when running a UP kernel on a CPU other than 0. This can happen when kexecing a UP image from an SMP kernel. In the future, multi-cluster systems running AMP configurations will require something similar for mapping cluster IDs, so it makes sense to decouple this logic in preparation for this support. Acked-by: Yang Bai <hamo.by@gmail.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reported-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-01-19ARM: fix rcu stalls on SMP platformsRussell King
We can stall RCU processing on SMP platforms if a CPU sits in its idle loop for a long time. This happens because we don't call irq_enter() and irq_exit() around generic_smp_call_function_interrupt() and friends. Add the necessary calls, and remove the one from within ipi_timer(), so that they're all in a common place. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-12ARM: stop: execute platform callback from cpu_stop codeWill Deacon
Sending IPI_CPU_STOP to a CPU causes it to execute a busy cpu_relax loop forever. This makes it impossible to kexec successfully on an SMP system since the secondary CPUs do not reset. This patch adds a callback to platform_cpu_kill, defined when CONFIG_HOTPLUG_CPU=y, from the ipi_cpu_stop handling code. This function currently just returns 1 on all platforms that define it but allows them to do something more sophisticated in the future. Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-12-06ARM: SMP: use idmap_pgd for mapping MMU enable during secondary bootingWill Deacon
The ARM SMP booting code allocates a temporary set of page tables containing an identity mapping of the kernel image and provides this to secondary CPUs for initial booting. In reality, we only need to include the __turn_mmu_on function in the identity mapping since the rest of the kernel is executing from virtual addresses after this point. This patch adds __turn_mmu_on to the .idmap.text section, allowing the SMP booting code to use the idmap_pgd directly and not have to populate its own set of page table. As a result of this patch, we can make the identity_mapping_add function static (since it is only used within mm/idmap.c) and also remove the identity_mapping_del function. The identity map population is moved to an early initcall so that it is setup in time for secondary CPU bringup. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-12-06ARM: idmap: populate identity map pgd at init time using .init.textWill Deacon
When disabling and re-enabling the MMU, it is necessary to take out an identity mapping for the code that manipulates the SCTLR in order to avoid it disappearing from under our feet. This is useful when soft rebooting and returning from CPU suspend. This patch allocates a set of page tables during boot and populates them with an identity mapping for the .idmap.text section. This means that users of the identity map do not need to manage their own pgd and can instead annotate their functions with __idmap or, in the case of assembly code, place them in the correct section. Acked-by: Dave Martin <dave.martin@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-10-28Merge branch 'devel-stable' of ↵Linus Torvalds
http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm * 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm: (178 commits) ARM: 7139/1: fix compilation with CONFIG_ARM_ATAG_DTB_COMPAT and large TEXT_OFFSET ARM: gic, local timers: use the request_percpu_irq() interface ARM: gic: consolidate PPI handling ARM: switch from NO_MACH_MEMORY_H to NEED_MACH_MEMORY_H ARM: mach-s5p64x0: remove mach/memory.h ARM: mach-s3c64xx: remove mach/memory.h ARM: plat-mxc: remove mach/memory.h ARM: mach-prima2: remove mach/memory.h ARM: mach-zynq: remove mach/memory.h ARM: mach-bcmring: remove mach/memory.h ARM: mach-davinci: remove mach/memory.h ARM: mach-pxa: remove mach/memory.h ARM: mach-ixp4xx: remove mach/memory.h ARM: mach-h720x: remove mach/memory.h ARM: mach-vt8500: remove mach/memory.h ARM: mach-s5pc100: remove mach/memory.h ARM: mach-tegra: remove mach/memory.h ARM: plat-tcc: remove mach/memory.h ARM: mach-mmp: remove mach/memory.h ARM: mach-cns3xxx: remove mach/memory.h ... Fix up mostly pretty trivial conflicts in: - arch/arm/Kconfig - arch/arm/include/asm/localtimer.h - arch/arm/kernel/Makefile - arch/arm/mach-shmobile/board-ap4evb.c - arch/arm/mach-u300/core.c - arch/arm/mm/dma-mapping.c - arch/arm/mm/proc-v7.S - arch/arm/plat-omap/Kconfig largely due to some CONFIG option renaming (ie CONFIG_PM_SLEEP -> CONFIG_ARM_CPU_SUSPEND for the arm-specific suspend code etc) and addition of NEED_MACH_MEMORY_H next to HAVE_IDE.
2011-10-26Merge branch 'core-locking-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) rtmutex: Add missing rcu_read_unlock() in debug_rt_mutex_print_deadlock() lockdep: Comment all warnings lib: atomic64: Change the type of local lock to raw_spinlock_t locking, lib/atomic64: Annotate atomic64_lock::lock as raw locking, x86, iommu: Annotate qi->q_lock as raw locking, x86, iommu: Annotate irq_2_ir_lock as raw locking, x86, iommu: Annotate iommu->register_lock as raw locking, dma, ipu: Annotate bank_lock as raw locking, ARM: Annotate low level hw locks as raw locking, drivers/dca: Annotate dca_lock as raw locking, powerpc: Annotate uic->lock as raw locking, x86: mce: Annotate cmci_discover_lock as raw locking, ACPI: Annotate c3_lock as raw locking, oprofile: Annotate oprofilefs lock as raw locking, video: Annotate vga console lock as raw locking, latencytop: Annotate latency_lock as raw locking, timer_stats: Annotate table_lock as raw locking, rwsem: Annotate inner lock as raw locking, semaphores: Annotate inner lock as raw locking, sched: Annotate thread_group_cputimer as raw ... Fix up conflicts in kernel/posix-cpu-timers.c manually: making cputimer->cputime a raw lock conflicted with the ABBA fix in commit bcd5cff7216f ("cputimer: Cure lock inversion").
2011-10-25Merge branch 'misc' into for-linusRussell King
Conflicts: arch/arm/mach-integrator/integrator_ap.c
2011-10-23ARM: 7133/1: SMP: fix per cpu timer setup before the cpu is marked onlineThomas Gleinxer
The problem is related to the early enabling of interrupts and the per cpu timer setup before the cpu is marked online. This doesn't need to be done in order to call calibrate_delay(). calibrate_delay() monitors jiffies, which are updated from the CPU which is waiting for the new CPU to set the online bit. So simply calibrate_delay() can be called on the new CPU just from the interrupt disabled region and move the local timer setup after stored the cpu data and before enabling interrupts. This solves both the cpu_online vs. cpu_active problem and the affinity setting of the per cpu timers. Signed-off-by: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-23ARM: gic, local timers: use the request_percpu_irq() interfaceMarc Zyngier
This patch remove the hardcoded link between local timers and PPIs, and convert the PPI users (TWD, MCT and MSM timers) to the new *_percpu_irq interface. Also some collateral cleanup (local_timer_ack() is gone, and the interrupt handler is strictly private to each driver). PPIs are now useable for more than just the local timers. Additional testing by David Brown (msm8250 and msm8660) and Shawn Guo (imx6q). Cc: David Brown <davidb@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Brown <davidb@codeaurora.org> Tested-by: David Brown <davidb@codeaurora.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2011-10-23ARM: gic: consolidate PPI handlingMarc Zyngier
PPI handling is a bit of an odd beast. It uses its own low level handling code and is hardwired to the local timers (hence lacking a registration interface). Instead, switch the low handling to the normal SPI handling code. PPIs are handled by the handle_percpu_devid_irq flow. This also allows the removal of some duplicated code. Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: David Brown <davidb@codeaurora.org> Cc: Bryan Huntsman <bryanh@codeaurora.org> Cc: Tony Lindgren <tony@atomide.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Brown <davidb@codeaurora.org> Tested-by: David Brown <davidb@codeaurora.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2011-10-17ARM: 7115/4: move __exception and friends to asm/exception.hJamie Iles
The definition of __exception_irq_entry for CONFIG_FUNCTION_GRAPH_TRACER=y needs linux/ftrace.h, but this creates a circular dependency with it's current home in asm/system.h. Create asm/exception.h and update all current users. v4: - rebase to rmk/for-next v3: - remove redundant includes of linux/ftrace.h v2: - document the usage restricitions of __exception* Cc: Zoltan Devai <zdevai@gmail.com> Signed-off-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17ARM: 7124/1: smp: Add a localtimer handler callable from C codeShawn Guo
In order to be able to handle localtimer directly from C code instead of assembly code, introduce handle_local_timer(), which is modeled after handle_IRQ(). Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17ARM: 7123/1: smp: Add an IPI handler callable from C codeShawn Guo
In order to be able to handle IPI directly from C code instead of assembly code, introduce handle_IPI(), which is modeled after handle_IRQ(). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17ARM: 7060/1: smp: populate logical CPU mapping during bootWill Deacon
To allow booting Linux on a CPU with physical ID != 0, we need to provide a mapping from the logical CPU number to the physical CPU number. This patch adds such a mapping and populates it during boot. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17ARM: 7011/1: Add ARM cpu topology definitionVincent Guittot
The affinity between ARM processors is defined in the MPIDR register. We can identify which processors are in the same cluster, and which ones have performance interdependency. We can define the cpu topology of ARM platform, that is then used by sched_mc and sched_smt. The default state of sched_mc and sched_smt config is disable. When enabled, the behavior of the scheduler can be modified with sched_mc_power_savings and sched_smt_power_savings sysfs interfaces. Changes since v4 : * Remove unnecessary parentheses and blank lines Changes since v3 : * Update the format of printk message * Remove blank line Changes since v2 : * Update the commit message and some comments Changes since v1 : * Update the commit message * Add read_cpuid_mpidr in arch/arm/include/asm/cputype.h * Modify header of arch/arm/kernel/topology.c * Modify tests and manipulation of MPIDR's bitfields * Modify the place and dependancy of the config * Modify Noop functions Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-13locking, ARM: Annotate low level hw locks as rawThomas Gleixner
Annotate the low level hardware locks which must not be preempted. In mainline this change documents the low level nature of the lock - otherwise there's no functional difference. Lockdep and Sparse checking will work as usual. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-22Merge branches 'btc', 'dma', 'entry', 'fixes', 'linker-layout', 'misc', ↵Russell King
'mmci', 'suspend' and 'vfp' into for-next
2011-07-07ARM: 6993/1: platsmp: Allow secondary cpu hotplug with maxcpus=1Stephen Boyd
If an ARM system has multiple cpus in the same socket and the kernel is booted with maxcpus=1, secondary cpus are possible but not present due to how platform_smp_prepare_cpus() is called. Since most typical ARM processors don't actually support physical hotplug, initialize the present map to be equal to the possible map in generic ARM SMP code. Also, always call platform_smp_prepare_cpus() as long as max_cpus is non-zero (0 means no SMP) to allow platform code to do any SMP setup. After applying this patch it's possible to boot an ARM system with maxcpus=1 on the command line and then hotplug in secondary cpus via sysfs. This is more in line with how x86 does things. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: David Brown <davidb@codeaurora.org> Cc: Tony Lindgren <tony@atomide.com> Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Cc: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-21ARM: SMP: wait for CPU to be marked activeRussell King
When we bring a CPU online, we should wait for it to become active before entering the idle thread, so we know that the scheduler and thread migration is going to work. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-26ARM: 6942/1: mm: make TTBR1 always point to swapper_pg_dir on ARMv6/7Catalin Marinas
This patch makes TTBR1 point to swapper_pg_dir so that global, kernel mappings can be used exclusively on v6 and v7 cores where they are needed. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-23Merge branches 'consolidate-clksrc', 'consolidate-flash', ↵Russell King
'consolidate-generic', 'consolidate-smp', 'consolidate-stmp' and 'consolidate-zones' into consolidate
2011-05-23ARM: consolidate SMP cross call implementationRussell King
Rather than having each platform class provide a mach/smp.h header for smp_cross_call(), arrange for them to register the function with the core ARM SMP code instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-12Merge commit 'v2.6.39-rc7' into sched/coreIngo Molnar
2011-04-27ARM: 6887/1: Mark broadcast_timer_setup() __cpuinitStephen Boyd
This function is only called by percpu_timer_setup() which is also __cpuinit marked. Thus it's safe to mark this function as __cpuinit as well. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-04-14sched: Provide scheduler_ipi() callback in response to smp_send_reschedule()Peter Zijlstra
For future rework of try_to_wake_up() we'd like to push part of that function onto the CPU the task is actually going to run on. In order to do so we need a generic callback from the existing scheduler IPI. This patch introduces such a generic callback: scheduler_ipi() and implements it as a NOP. BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions! Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
2011-02-23ARM: 6759/1: smp: Select local timers vs broadcast timer support runtimeSantosh Shilimkar
The current code support of dummy timers in absence of local timer is compile time. This is an attempt to convert it to runtime so that on few SOC version if the local timers aren't supported kernel can switch to dummy timers. OMAP4430 ES1.0 does suffer from this limitation. This patch should not have any functional impact on affected files. Cc: Daniel Walker <dwalker@codeaurora.org> Cc: Bryan Huntsman <bryanh@codeaurora.org> Cc: Tony Lindgren <tony@atomide.com> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Colin Cross <ccross@android.com> Cc: Erik Gilling <konkers@android.com> Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Cc: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: David Brown <davidb@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-06Merge branch 'pgt' (early part) into develRussell King
2011-01-06Merge branch 'misc' into develRussell King
Conflicts: arch/arm/Kconfig arch/arm/common/Makefile arch/arm/kernel/Makefile arch/arm/kernel/smp.c
2011-01-05Merge branch 'clksrc' into develRussell King
Conflicts: arch/arm/mach-vexpress/v2m.c arch/arm/plat-omap/counter_32k.c arch/arm/plat-versatile/Makefile