From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Tue, 6 Sep 2016 16:33:57 +0100 Subject: [PATCH v24 0/9] arm64: add kdump support In-Reply-To: <976ca1f8-5efb-b45c-19b8-bde7bd06f5b8@caviumnetworks.com> References: <20160809015248.28414-1-takahiro.akashi@linaro.org> <0267060a-d380-2e7a-0c33-0084bfc46d97@caviumnetworks.com> <20160831053109.GR20080@linaro.org> <20160905081501.GA16712@linaro.org> <976ca1f8-5efb-b45c-19b8-bde7bd06f5b8@caviumnetworks.com> Message-ID: <57CEE1E5.7040206@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 05/09/16 13:42, Manish Jaggi wrote: > > > On 09/05/2016 01:45 PM, AKASHI Takahiro wrote: >> [Cc: Marc] >> >> On Fri, Sep 02, 2016 at 06:23:25PM +0530, Manish Jaggi wrote: >>> >>> >>> On 08/31/2016 11:01 AM, AKASHI Takahiro wrote: >>>> Manish, >>>> >>>> Thank you for testing my kdump and reporting issues. >>>> >>>> On Wed, Aug 31, 2016 at 09:11:52AM +0530, Manish Jaggi wrote: >>>>> Hi Akashi, >>>>> >>>>> On 08/09/2016 07:22 AM, AKASHI Takahiro wrote: >>>>>> This patch series adds kdump support on arm64. >>>>>> >>>>>> To load a crash-dump kernel to the systems, a series of patches to >>>>>> kexec-tools, which have not yet been merged upstream, are needed. >>>>>> Please use my kdump patches [1]. >>>>>> >>>>>> To examine vmcore (/proc/vmcore) on a crash-dump kernel, you can use >>>>>> - crash utility (coming v7.1.6 or later) [2] >>>>>> (Necessary patches have already been queued in the master.) >>>>>> >>>>>> [1] T.B.D. >>>>>> [2] https://github.com/crash-utility/crash.git >>>>>> >>>>>> Changes for v24 (Aug 9, 2016): >>>>>> o Rebase to Linux-4.8-rc1 >>>>>> o Update descriptions about newly added DT proerties >>>>>> >>>>>> Changes for v23 (July 26, 2016): >>>>>> >>>>>> o Move memblock_reserve() to a single place in reserve_crashkernel() >>>>>> o Use cpu_park_loop() in ipi_cpu_crash_stop() >>>>>> o Always enforce ARCH_LOW_ADDRESS_LIMIT to the memory range of crash kernel >>>>>> o Re-implement fdt_enforce_memory_region() to remove non-reserve regions >>>>>> (for ACPI) from usable memory at crash kernel >>>>>> >>>>>> Changes for v22 (July 12, 2016): >>>>>> >>>>>> o Export "crashkernel-base" and "crashkernel-size" via device-tree, >>>>>> and add some descriptions about them in chosen.txt >>>>>> o Rename "usable-memory" to "usable-memory-range" to avoid inconsistency >>>>>> with powerpc's "usable-memory" >>>>>> o Make cosmetic changes regarding "ifdef" usage >>>>>> o Correct some wordings in kdump.txt >>>>>> >>>>>> Changes for v21 (July 6, 2016): >>>>>> >>>>>> o Remove kexec patches. >>>>>> o Rebase to arm64's for-next/core (Linux-4.7-rc4 based). >>>>>> o Clarify the description about kvm in kdump.txt. >>>>>> >>>>>> See the following link [3] for older changes: >>>>>> [3] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-June/438780.html >>>>>> >>>>>> AKASHI Takahiro (8): >>>>>> arm64: kdump: reserve memory for crash dump kernel >>>>>> memblock: add memblock_cap_memory_range() >>>>>> arm64: limit memory regions based on DT property, usable-memory-range >>>>>> arm64: kdump: implement machine_crash_shutdown() >>>>>> arm64: kdump: add kdump support >>>>>> arm64: kdump: add VMCOREINFO's for user-space coredump tools >>>>>> arm64: kdump: enable kdump in the arm64 defconfig >>>>>> arm64: kdump: update a kernel doc >>>>>> >>>>>> James Morse (1): >>>>>> Documentation: dt: chosen properties for arm64 kdump >>>>>> >>>>>> Documentation/devicetree/bindings/chosen.txt | 45 ++++++ >>>>>> Documentation/kdump/kdump.txt | 16 ++- >>>>>> arch/arm64/Kconfig | 11 ++ >>>>>> arch/arm64/configs/defconfig | 1 + >>>>>> arch/arm64/include/asm/hardirq.h | 2 +- >>>>>> arch/arm64/include/asm/kexec.h | 41 +++++- >>>>>> arch/arm64/include/asm/smp.h | 2 + >>>>>> arch/arm64/kernel/Makefile | 1 + >>>>>> arch/arm64/kernel/crash_dump.c | 71 ++++++++++ >>>>>> arch/arm64/kernel/machine_kexec.c | 67 ++++++++- >>>>>> arch/arm64/kernel/setup.c | 7 +- >>>>>> arch/arm64/kernel/smp.c | 63 +++++++++ >>>>>> arch/arm64/mm/init.c | 202 +++++++++++++++++++++++++++ >>>>>> include/linux/memblock.h | 1 + >>>>>> mm/memblock.c | 28 ++++ >>>>>> 15 files changed, 551 insertions(+), 7 deletions(-) >>>>>> create mode 100644 arch/arm64/kernel/crash_dump.c >>>>>> >>>>> Couple of points >>>>> a) Just a note, while testing, the crashkernel reserved memory should be less than ARCH_LOW_ADDRESS_LIMIT (=arm64_dma_phys_limit). >>>> >>>> I think that this is a common mistake not only for kdump, but also >>>> for general kernels. >>>> Since request_standard_resources() calls alloc_bootmem_low(), >>>> the kernel will panic if any of usable "System RAM" is located >>>> above ARCH_LOW_ADDRESS_LIMIT. >>>> For kdump, using "crashkernel=SS" notation is a convenient way >>>> to avoid this issue. >>>> >>>>> b) Has anyone tested this on a SoC with Gicv3 ITS ? >>>>> Should the GICD/R be reset prior to switching to crash kernel ? >>>>> I am seeing lot of GICv3: RWP timeout, gone fishing while crash kernel boots. >>>> >>>> I've never seen this kind of messages. >>>> I usually do my testing on a fast model. >>>> "compatible" of interrupt-controller is "arm,gic-v3." >>>> >>> I suspect gic_cpu_pm_notifier is not being called on any of the cores prior to start of crash kernel. >>> We might have to call it explicitly. >> >> I'm not sure that it is the cause, but anyway none of any cpu_pm_notifier's >> will be called at panic. That is the reason why "maxcpus=1" should be >> specified (for kdump on arm64). >> > What I meant was that since cpu_pm_notifier is not called before > crash kernel is started, GIC Distributor/re-distributor/ITS is not > set in quiescent state. Which is fine, they are not expected to be in a sane state anyway (that's what a crash is about...). The ITS now has provision to be put in a disabled state before being reinitialized. As for GICD, it is disabled before being reprogrammed, which should be enough. > In my setup the GICD_CTRL[RWP] bit is not cleared in the > crashkernels' distributor init function. Which instance is failing? The initial one (just after the initial disable)? Or the one called from gic_dist_config()? Thanks, M. -- Jazz is not dead. It just smells funny...