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* arm64: ftrace: fix a stack tracer's output under function graph tracerAKASHI Takahiro2015-12-211-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Function graph tracer modifies a return address (LR) in a stack frame to hook a function return. This will result in many useless entries (return_to_handler) showing up in a) a stack tracer's output b) perf call graph (with perf record -g) c) dump_backtrace (at panic et al.) For example, in case of a), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo 1 > /proc/sys/kernel/stack_trace_enabled $ cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (54 entries) ----- ---- -------- 0) 4504 16 gic_raise_softirq+0x28/0x150 1) 4488 80 smp_cross_call+0x38/0xb8 2) 4408 48 return_to_handler+0x0/0x40 3) 4360 32 return_to_handler+0x0/0x40 ... In case of b), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ perf record -e mem:XXX:x -ag -- sleep 10 $ perf report ... | | |--0.22%-- 0x550f8 | | | 0x10888 | | | el0_svc_naked | | | sys_openat | | | return_to_handler | | | return_to_handler ... In case of c), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo c > /proc/sysrq-trigger ... Call trace: [<ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30 [<ffffffc000092250>] return_to_handler+0x0/0x40 [<ffffffc000092250>] return_to_handler+0x0/0x40 ... This patch replaces such entries with real addresses preserved in current->ret_stack[] at unwind_frame(). This way, we can cover all the cases. Reviewed-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [will: fixed minor context changes conflicting with irq stack bits] Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: pass a task parameter to unwind_frame()AKASHI Takahiro2015-12-211-1/+1
| | | | | | | | | | | | | | | | | | Function graph tracer modifies a return address (LR) in a stack frame to hook a function's return. This will result in many useless entries (return_to_handler) showing up in a call stack list. We will fix this problem in a later patch ("arm64: ftrace: fix a stack tracer's output under function graph tracer"). But since real return addresses are saved in ret_stack[] array in struct task_struct, unwind functions need to be notified of, in addition to a stack pointer address, which task is being traced in order to find out real return addresses. This patch extends unwind functions' interfaces by adding an extra argument of a pointer to task_struct. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* clocksource: cosmetic: Drop OF 'dependency' from symbolsMarc Zyngier2015-10-011-1/+1
| | | | | | | | | | | | | Seeing the 'of' characters in a symbol that is being called from ACPI seems to freak out people. So let's do a bit of pointless renaming so that these folks do feel at home. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* clocksource / arm_arch_timer: Convert to ACPI probingMarc Zyngier2015-10-011-6/+0
| | | | | | | | | | | | | It is now absolutely trivial to convert the arch timer driver to use ACPI probing, just like its DT counterpart. Let's enjoy another crapectomy. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* arm64: force CONFIG_SMP=y and remove redundant #ifdefsWill Deacon2015-07-271-2/+0
| | | | | | | | | | | Nobody seems to be producing !SMP systems anymore, so this is just becoming a source of kernel bugs, particularly if people want to use coherent DMA with non-shared pages. This patch forces CONFIG_SMP=y for arm64, removing a modest amount of code in the process. Signed-off-by: Will Deacon <will.deacon@arm.com>
* clocksource / arch_timer: Parse GTDT to initialize arch timerHanjun Guo2015-03-261-0/+7
| | | | | | | | | | | | | | | | | | | | Using the information presented by GTDT (Generic Timer Description Table) to initialize the arch timer (not memory-mapped). CC: Daniel Lezcano <daniel.lezcano@linaro.org> CC: Thomas Gleixner <tglx@linutronix.de> Originally-by: Amit Daniel Kachhap <amit.daniel@samsung.com> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Tested-by: Yijing Wang <wangyijing@huawei.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Tested-by: Timur Tabi <timur@codeaurora.org> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Robert Richter <rrichter@cavium.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: kernel: initialize broadcast hrtimer based clock event deviceLorenzo Pieralisi2014-05-301-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On platforms implementing CPU power management, the CPUidle subsystem can allow CPUs to enter idle states where local timers logic is lost on power down. To keep the software timers functional the kernel relies on an always-on broadcast timer to be present in the platform to relay the interrupt signalling the timer expiries. For platforms implementing CPU core gating that do not implement an always-on HW timer or implement it in a broken way, this patch adds code to initialize the kernel hrtimer based clock event device upon boot (which can be chosen as tick broadcast device by the kernel). It relies on a dynamically chosen CPU to be always powered-up. This CPU then relays the timer interrupt to CPUs in deep-idle states through its HW local timer device. Having a CPU always-on has implications on power management platform capabilities and makes CPUidle suboptimal, since at least a CPU is kept always in a shallow idle state by the kernel to relay timer interrupts, but at least leaves the kernel with a functional system with some working power management capabilities. The hrtimer based clock event device is unconditionally registered, but has the lowest possible rating such that any broadcast-capable HW clock event device present will be chosen in preference as the tick broadcast device. Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: init: Move of_clk_init to time_initChanho Min2014-04-251-0/+2
| | | | | | | | | | Clock providers should be initialized before clocksource_of_init. If not, Clock source initialization can be fail to get the clock. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Chanho Min <chanho.min@lge.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arch_timer: Move to generic sched_clock frameworkStephen Boyd2013-10-101-10/+0
| | | | | | | | | | | | | | | | | | | | Register with the generic sched_clock framework now that it supports 64 bits. This fixes two problems with the current sched_clock support for machines using the architected timers. First off, we don't subtract the start value from subsequent sched_clock calls so we can potentially start off with sched_clock returning gigantic numbers. Second, there is no support for suspend/resume handling so problems such as discussed in 6a4dae5 (ARM: 7565/1: sched: stop sched_clock() during suspend, 2012-10-23) can happen without this patch. Finally, it allows us to move the sched_clock setup into drivers clocksource out of the arch ports. Cc: Christopher Covington <cov@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* arm64: kernel: compiling issue, need delete read_current_timer()Chen Gang2013-06-101-6/+0
| | | | | | | | | | | | | | | | Under arm64, we will calibrate the delay loop statically using a known timer frequency, so delete read_current_timer(), or it will cause compiling issue with allmodconfig. The related error: ERROR: "read_current_timer" [lib/rbtree_test.ko] undefined! ERROR: "read_current_timer" [lib/interval_tree_test.ko] undefined! ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined! ERROR: "read_current_timer" [crypto/tcrypt.ko] undefined! Signed-off-by: Chen Gang <gang.chen@asianux.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* ARM: convert arm/arm64 arch timer to use CLKSRC_OF initRob Herring2013-04-111-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | This converts arm and arm64 to use CLKSRC_OF DT based initialization for the arch timer. A new function arch_timer_arch_init is added to allow for arch specific setup. This has a side effect of enabling sched_clock on omap5 and exynos5. There should not be any reason not to use the arch timers for sched_clock. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Simon Horman <horms@verge.net.au> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-samsung-soc@vger.kernel.org Cc: linux-omap@vger.kernel.org Cc: linux-sh@vger.kernel.org Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
* arm64: move from arm_generic to arm_arch_timerMark Rutland2013-01-311-2/+27
| | | | | | | | | | | | | | | The arch_timer driver supports a superset of the functionality of the arm_generic driver, and is not tied to a particular arch. This patch moves arm64 to use the arch_timer driver, gaining additional functionality in doing so, and removes the (now unused) arm_generic driver. Timer-related hooks specific to arm64 are moved into arch/arm64/kernel/time.c. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
* arm64: Generic timers supportMarc Zyngier2012-09-171-0/+65
This patch adds support for the ARM generic timers with A64 instructions for accessing the timer registers. It uses the physical counter as the clock source and the virtual counter as sched_clock. The timer frequency can be specified via DT or read from the CNTFRQ_EL0 register. The physical counter is also accessible from user space allowing fast gettimeofday() implementation. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>