linaro-kernel December 2013

linaro-kernel@lists.linaro.org

83 participants
265 discussions

by vijay.kilari＠gmail.com

From: Vijaya Kumar K <Vijaya.Kumar(a)caviumnetworks.com> Based on the step-handler and break-handler hooks patch from Sandeepa, KGDB debugging support is added for EL1 debug in AArch64 mode. Any updates that come for Patch 1 from Sandeepa will be rebased in next version With second patch,register layout is updated to be inline with GDB tool. Basic GDB connection, break point set/clear and info commands are supported except step/next debugging With third patch, step/next debugging support is added, where in pc is updated to point to the instruction to be stepped and stopped. With fourth patch, the compile time breakpoint instruction reordering is fixed by making kgbd_breakpoint() as noinline Tested with ARM64 simulator v6: - Change pstate register to 8 bytes to make endian nuetral. Use GDB below GDB patch to display pstate in Big endian mode. https://sourceware.org/ml/gdb-patches/2013-12/msg00720.html Thanks to Andrew. v5: - Updated BRK #imm16 value to 0x400 & 0x401 as per recommendation as per Marcus recommendataion http://patchwork.ozlabs.org/patch/290801/ - Rebased to 3.13 AArch64 kernel v4: - Updated kgdb_single_step and kgdb_cpu_doing_single_step variables properly based on gdb state v3: - Rebased to v4 version of Sandeepa Prabhu's patch (patch 1) - Made dynamic break point instruction encoding generic - Made ESR value encoding generic for dynamic and compile break point - Used memcpy and memset to copy register contents to gdb buffer - Fixed reordering of break point instruction by compiler with patch 3 - Rebased against AAach64 upstream kernel v2: - Moved break instruction encoding to debug-monitors.h file - Fixed endianess of compile break instruction encoding - Updated I/O buffer sizes - Updated register buffer size - Remove changes to debug_exception handler in entry.S for - ELR update and step debugging with update pc instead of ELR - Rebased against AArch64 upstream kernel v1: - Initial patch-set Vijaya Kumar K (3): AArch64: KGDB: Add Basic KGDB support AArch64: KGDB: Add step debugging support KGDB: make kgdb_breakpoint() as noinline arch/arm64/include/asm/debug-monitors.h | 47 +++++ arch/arm64/include/asm/kgdb.h | 86 ++++++++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/kgdb.c | 341 +++++++++++++++++++++++++++++++ kernel/debug/debug_core.c | 2 +- 5 files changed, 476 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/kgdb.h create mode 100644 arch/arm64/kernel/kgdb.c -- 1.7.9.5

10 years, 11 months

[PATCH 1/2] sched/nohz: add debugfs control over sched_tick_max_deferment

by Kevin Hilman

Allow debugfs override of sched_tick_max_deferment in order to ease finding/fixing the remaining issues with full nohz. The value to be written is in jiffies, and -1 means the max deferment is disabled (scheduler_tick_max_deferment() returns KTIME_MAX.) Cc: Frederic Weisbecker <fweisbec(a)gmail.com> Signed-off-by: Kevin Hilman <khilman(a)linaro.org> --- kernel/sched/core.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5ac63c9a995a..4b1fe3e69fe4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2175,6 +2175,8 @@ void scheduler_tick(void) } #ifdef CONFIG_NO_HZ_FULL +static u32 sched_tick_max_deferment = HZ; + /** * scheduler_tick_max_deferment * @@ -2193,13 +2195,25 @@ u64 scheduler_tick_max_deferment(void) struct rq *rq = this_rq(); unsigned long next, now = ACCESS_ONCE(jiffies); - next = rq->last_sched_tick + HZ; + if (sched_tick_max_deferment == -1) + return KTIME_MAX; + + next = rq->last_sched_tick + sched_tick_max_deferment; if (time_before_eq(next, now)) return 0; return jiffies_to_usecs(next - now) * NSEC_PER_USEC; } + +static __init int sched_nohz_full_init_debug(void) +{ + debugfs_create_u32("sched_tick_max_deferment", 0644, NULL, + &sched_tick_max_deferment); + + return 0; +} +late_initcall(sched_nohz_full_init_debug); #endif notrace unsigned long get_parent_ip(unsigned long addr) -- 1.8.3

10 years, 11 months

Re: [PATCH] serial: samsung: Remove hard-coded major/minor numbers

by Tushar Behera

On 28 December 2013 00:14, Greg KH <gregkh(a)linuxfoundation.org> wrote: > On Fri, Dec 27, 2013 at 03:47:31PM +0530, Tushar Behera wrote: >> On 27 December 2013 12:08, Greg KH <gregkh(a)linuxfoundation.org> wrote: >> > On Fri, Dec 27, 2013 at 12:00:20PM +0530, Tushar Behera wrote: >> >> On 27 December 2013 10:48, Greg KH <gregkh(a)linuxfoundation.org> wrote: >> >> > On Fri, Dec 27, 2013 at 10:37:28AM +0530, Tushar Behera wrote: >> >> [ ... ] >> >> >> >> @@ -951,8 +949,6 @@ static struct uart_driver s3c24xx_uart_drv = { >> >> >> .nr = CONFIG_SERIAL_SAMSUNG_UARTS, >> >> >> .cons = S3C24XX_SERIAL_CONSOLE, >> >> >> .dev_name = S3C24XX_SERIAL_NAME, >> >> >> - .major = S3C24XX_SERIAL_MAJOR, >> >> >> - .minor = S3C24XX_SERIAL_MINOR, >> >> > >> >> > Doesn't this break existing systems and configurations that are >> >> > expecting 204:64 as the location of this serial port? >> >> > >> >> >> >> I tested this on Exynos4210-Origen, Exynos5250-Arndale board, it works >> >> fine there. I haven't tested on any older boards. >> > >> > How did it work? You are relying on some userspace tools to do this >> > properly, right? What about systems without those specific tools? >> > >> >> Enabling CONFIG_DEVTMPFS, all the /dev/ttySAC<n> nodes are generated >> and the appropriate console is specified through command line >> argument. > > But what about systems that rely on a hard-coded /dev? > > Look, I'm all for making everyone use devtmpfs, but just changing > major:minor numbers for drivers isn't ok, as you are changing the > userspace ABI for the device. > > Please realize what you are asking for here, I really don't think you > grasp it given that you didn't ask any of the maintainers of this driver > about the change in the first place. > > Please get approval for this patch from others within Linaro before > sending it out again. Linaro has a process in place for this type of > thing, please use it, otherwise it makes people like me really grumpy > and upset and causes me to yell at people at their conferences. > > greg k-h Asking for opinion about this ... Without this patch, I can't get serial console to come up on Exynos platforms when amba-pl011 driver enabled. But Greg is particularly not at all happy with this patch. Any comments with respect to fixing this issue would be highly appreciated. Attaching the complete patch for reference. -- Tushar Behera

10 years, 11 months

[PATCH 0/5] ARM: kprobes: big endian support

by Taras Kondratiuk

Reworked initial Ben's series for big endian support [1]. Dropped patches that are not directly related to kprobes. Current set of patches is enough to have functional BE kprobes. All kprobes-tests pass in any LE/BE and ARM/Thumb combination. Based on v3.13-rc5. [1] http://www.spinics.net/lists/arm-kernel/msg285210.html Ben Dooks (4): ARM: kprobes: fix instruction fetch order with <asm/opcodes.h> ARM: kprobes-test: use <asm/opcodes.h> for instruction accesses ARM: kprobes-test: use <asm/opcodes.h> for ARM instruction building ARM: kprobes-test: use <asm/opcodes.h> for Thumb instruction building Taras Kondratiuk (1): ARM: kprobes-test: Workaround GAS .align bug arch/arm/kernel/kprobes-common.c | 19 +- arch/arm/kernel/kprobes-test-arm.c | 595 +++++++++++++++++----------------- arch/arm/kernel/kprobes-test-thumb.c | 447 ++++++++++++------------- arch/arm/kernel/kprobes-test.c | 14 +- arch/arm/kernel/kprobes-test.h | 2 +- arch/arm/kernel/kprobes-thumb.c | 20 +- arch/arm/kernel/kprobes.c | 9 +- 7 files changed, 558 insertions(+), 548 deletions(-) -- 1.7.9.5

10 years, 11 months

[PATCH v3 0/2] PSCI system off and reset for KVM ARM/ARM64

by Anup Patel

The Power State and Coordination Interface (PSCI) specification defines SYSTEM_OFF and SYSTEM_RESET functions for system poweroff and reboot. This patchset adds emulation of PSCI SYSTEM_OFF and SYSTEM_RESET functions in KVM ARM/ARM64 by forwarding them to user space (QEMU or KVMTOOL) using KVM_EXIT_SYSTEM_EVENT exit reason. To try this patch from guest kernel, we will need PSCI-based restart and poweroff support in the guest kenel for both ARM and ARM64. Rob Herring has already submitted patches for PSCI-based restart and poweroff in ARM kernel but these are not merged yet due unstable device tree bindings of kernel PSCI support. We will be having similar patches for PSCI-based restart and poweroff in ARM64 kernel. (Refer http://www.spinics.net/lists/arm-kernel/msg262217.html) (Refer http://www.spinics.net/lists/devicetree/msg05348.html) Change Log: V3: - Simplify handle_hvc() for both ARM and ARM64 - Minor fix in comments for kvm_psci_call() V2: - Replace KVM_EXIT_RESET with KVM_EXIT_SYSTEM_EVENT - Make kvm_psci_call() return convention to match KVM ARM return convention V1: - Initial revised patch after RFC PATCH. Anup Patel (2): KVM: Add KVM_EXIT_SYSTEM_EVENT to user space API header ARM/ARM64: KVM: Forward PSCI SYSTEM_OFF and SYSTEM_RESET to user space Documentation/virtual/kvm/api.txt | 15 ++++++++++++ arch/arm/include/asm/kvm_psci.h | 2 +- arch/arm/include/uapi/asm/kvm.h | 2 ++ arch/arm/kvm/handle_exit.c | 11 ++++++--- arch/arm/kvm/psci.c | 47 ++++++++++++++++++++++++++++++------- arch/arm64/include/asm/kvm_psci.h | 2 +- arch/arm64/include/uapi/asm/kvm.h | 2 ++ arch/arm64/kvm/handle_exit.c | 10 +++++--- include/uapi/linux/kvm.h | 8 +++++++ 9 files changed, 83 insertions(+), 16 deletions(-) -- 1.7.9.5

10 years, 11 months

[PATCH] video: amba-clcd: Make CLCD driver available on more platforms

by Mark Brown

From: Mark Brown <broonie(a)linaro.org> The CLCD driver is used on ARM reference models for ARMv8 so add ARM64 to the list of dependencies. The driver also has no build time dependencies on ARM (stubs are provided for ARM-specific DMA functions in the code) so make it available with COMPILE_TEST in order to maximise build coverage. Signed-off-by: Mark Brown <broonie(a)linaro.org> --- drivers/video/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 4f2e1b35eb38..e6c7fb1a389b 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -312,7 +312,8 @@ config FB_PM2_FIFO_DISCONNECT config FB_ARMCLCD tristate "ARM PrimeCell PL110 support" - depends on FB && ARM && ARM_AMBA + depends on ARM || ARM64 || COMPILE_TEST + depends on FB && ARM_AMBA select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT -- 1.8.5.1

10 years, 11 months

[PATCH] ARM: traps: fix opcode endianness when read from user memory

by Taras Kondratiuk

Currently code has an inverted logic: opcode from user memory is swapped to a proper endianness only in case of read error. While normally opcode should be swapped only if it was read correctly from user memory. Signed-off-by: Ben Dooks <ben.dooks(a)codethink.co.uk> Signed-off-by: Taras Kondratiuk <taras.kondratiuk(a)linaro.org> --- arch/arm/kernel/traps.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 7940241..36a844e 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -425,9 +425,10 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) instr2 = __mem_to_opcode_thumb16(instr2); instr = __opcode_thumb32_compose(instr, instr2); } - } else if (get_user(instr, (u32 __user *)pc)) { + } else { + if (get_user(instr, (u32 __user *)pc)) + goto die_sig; instr = __mem_to_opcode_arm(instr); - goto die_sig; } if (call_undef_hook(regs, instr) == 0) -- 1.7.9.5

10 years, 11 months

kexec/kdump for arm64

by Geoff Levand

Hi All, Just for anyone who might be interested, I've started to do some work on kexec and kdump support for arm64. This work is being done within Linaro, so is tracked by their Jira system: https://cards.linaro.org/browse/CARD-563 I have these two git repos with my work-in-progress patches: https://git.linaro.org/gitweb?p=people/geoff/kexec-tools.git https://git.linaro.org/gitweb?p=people/geoff/linux-kexec.git As of now, I'm just trying to get the pieces in place for a basic kexec reboot. Kdump and advanced features will come later. Comments or suggestions welcome. -Geoff

10 years, 11 months

[PATCH] video: vgacon: Don't build on arm64

by Mark Brown

From: Mark Brown <broonie(a)linaro.org> arm64 is unlikely to have a VGA console and does not export screen_info causing build failures if the driver is build, for example in all*config. Add a dependency on !ARM64 to prevent this. This list is getting quite long, it may be easier to depend on a symbol which architectures that do support the driver can select. Signed-off-by: Mark Brown <broonie(a)linaro.org> --- drivers/video/console/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig index 846caab75a46..c39d6c42c3ef 100644 --- a/drivers/video/console/Kconfig +++ b/drivers/video/console/Kconfig @@ -8,7 +8,8 @@ config VGA_CONSOLE bool "VGA text console" if EXPERT || !X86 depends on !4xx && !8xx && !SPARC && !M68K && !PARISC && !FRV && \ !SUPERH && !BLACKFIN && !AVR32 && !MN10300 && !CRIS && \ - (!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER) + (!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER) \ + && !ARM64 default y help Saying Y here will allow you to use Linux in text mode through a -- 1.8.5.1

10 years, 11 months

[RFC][PATCH v5 00/14] sched: packing tasks

by Vincent Guittot

This is the 5th version of the previously named "packing small tasks" patchset. "small" has been removed because the patchset doesn't only target small tasks anymore. This patchset takes advantage of the new per-task load tracking that is available in the scheduler to pack the tasks in a minimum number of CPU/Cluster/Core. The packing mechanism takes into account the power gating topology of the CPUs to minimize the number of power domains that need to be powered on simultaneously. Most of the code has been put in fair.c file but it can be easily moved to another location. This patchset tries to solve one part of the larger energy-efficient scheduling problem and it should be merged with other proposals that solve other parts like the power-scheduler made by Morten. The packing is done in 3 steps: The 1st step creates a topology of the power gating of the CPUs that will help the scheduler to choose which CPUs will handle the current activity. This topology is described thanks to a new flag SD_SHARE_POWERDOMAIN that indicates whether the groups of CPUs of a scheduling domain share their power state. In order to be efficient, a group of CPUs that share their power state will be used (or not) simultaneously. By default, this flag is set in all sched_domain in order to keep the current behavior of the scheduler unchanged. The 2nd step evaluates the current activity of the system and creates a list of CPUs for handling it. The average activity level of CPUs is set to 80% but is configurable by changing the sched_packing_level knob. The activity level and the involvement of a CPU in the packing effort is evaluated during the periodic load balance similarly to cpu_power. Then, the default load balancing behavior is used to balance tasks between this reduced list of CPUs. As the current activity doesn't take into account a new task, an unused CPUs can also be selected during the 1st wake up and until the activity is updated. The 3rd step occurs when the scheduler selects a target CPU for a newly awakened task. The current wakeup latency of idle CPUs is used to select the one with the most shallow c-state. In some situation where the task load is small compared to the latency, the newly awakened task can even stay on the current CPU. Since the load is the main metric for the scheduler, the wakeup latency is transposed into an equivalent load so that the current mechanism of the load balance that is based on load comparison, is kept unchanged. A shared structure has been created to exchange information between scheduler and cpuidle (or any other framework that needs to share information). The wakeup latency is the only field for the moment but it could be extended with additional useful information like the target load or the expected sleep duration of a CPU. The patchset is based on v3.12-rc2 and is available in the git tree: git://git.linaro.org/people/vingu/kernel.git branch sched-packing-small-tasks-v5 If you want to test the patchset, you must enable CONFIG_PACKING_TASKS first. Then, you also need to create a arch_sd_local_flags that will clear the SD_SHARE_POWERDOMAIN flag at the appropriate level for your architecture. This has already be done for ARM architecture in the patchset. The figures below show the latency of cyclictest with and without the patchset on an ARM platform with a v3.11. The test has been runned 10 times on each kernel. #cyclictest -t 3 -q -e 1000000 -l 3000 -i 1800 -d 100 average (us) stdev v3.11 381,5 79,86 v3.11 + patches 173,83 13,62 Change since V4: - v4 posting:https://lkml.org/lkml/2013/4/25/396 - Keep only the aggressive packing mode. - Add a finer grain power domain description mechanism that includes DT description - Add a structure to share information with other framework - Use current wakeup latency of an idle CPU when selecting the target idle CPU - All the task packing mechanism can be disabled with a single config option Change since V3: - v3 posting: https://lkml.org/lkml/2013/3/22/183 - Take into account comments on previous version. - Add an aggressive packing mode and a knob to select between the various mode Change since V2: - v2 posting: https://lkml.org/lkml/2012/12/12/164 - Migrate only a task that wakes up - Change the light tasks threshold to 20% - Change the loaded CPU threshold to not pull tasks if the current number of running tasks is null but the load average is already greater than 50% - Fix the algorithm for selecting the buddy CPU. Change since V1: -v1 posting: https://lkml.org/lkml/2012/10/7/19 Patch 2/6 - Change the flag name which was not clear. The new name is SD_SHARE_POWERDOMAIN. - Create an architecture dependent function to tune the sched_domain flags Patch 3/6 - Fix issues in the algorithm that looks for the best buddy CPU - Use pr_debug instead of pr_info - Fix for uniprocessor Patch 4/6 - Remove the use of usage_avg_sum which has not been merged Patch 5/6 - Change the way the coherency of runnable_avg_sum and runnable_avg_period is ensured Patch 6/6 - Use the arch dependent function to set/clear SD_SHARE_POWERDOMAIN for ARM platform Vincent Guittot (14): sched: add a new arch_sd_local_flags for sched_domain init ARM: sched: clear SD_SHARE_POWERDOMAIN sched: define pack buddy CPUs sched: do load balance only with packing cpus sched: add a packing level knob sched: create a new field with available capacity sched: get CPU's activity statistic sched: move load idx selection in find_idlest_group sched: update the packing cpu list sched: init this_load to max in find_idlest_group sched: add a SCHED_PACKING_TASKS config sched: create a statistic structure sched: differantiate idle cpu cpuidle: set the current wake up latency arch/arm/include/asm/topology.h | 4 + arch/arm/kernel/topology.c | 50 ++++- arch/ia64/include/asm/topology.h | 3 +- arch/tile/include/asm/topology.h | 3 +- drivers/cpuidle/cpuidle.c | 11 ++ include/linux/sched.h | 13 +- include/linux/sched/sysctl.h | 9 + include/linux/topology.h | 11 +- init/Kconfig | 11 ++ kernel/sched/core.c | 11 +- kernel/sched/fair.c | 395 ++++++++++++++++++++++++++++++++++++-- kernel/sched/sched.h | 8 +- kernel/sysctl.c | 17 ++ 13 files changed, 521 insertions(+), 25 deletions(-) -- 1.7.9.5

10 years, 11 months

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linaro-kernel December 2013