On 09/06/2016 09:03 PM, Marc Zyngier wrote: > 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()? > In crash kernel, when the GICD_CTRL is set to 0x0, RWP is not getting clear. And is never cleared for any subsequent writes. > Thanks, > > M. >
