[PATCH v3 0/3] MCPM/TC2 support for CPU powerdown synchronisation
Vijay Kilari
vijay.kilari at gmail.com
Thu Oct 24 08:49:42 EDT 2013
Sorry. Below is the right DCC configuration for SCC 700
SCC: 0x700 0x0032F003 ;CFGRW48 - [25:24]Boot CPU [28]Boot
On Thu, Oct 24, 2013 at 6:18 PM, Vijay Kilari <vijay.kilari at gmail.com> wrote:
> Hi Dave Martin,
>
> With the below configuration, I tried to check cpu hotplug as this
> is prerequisite for kexec.
> I see cpu hotplug fails. hot-unplug is OK but hot plug-in fails.
>
> Below is my DCC board configuration
>
> SCC REGISTERS]
> TOTALSCCS: 32 ;Total Number of SCC registers
> SCC: 0x018 0x1FFFFFFF
> SCC: 0x01C 0xFF00FF00 ;CFGRW3 - SMC CS6/7 N/U
> SCC: 0x118 0x01CD1011 ;CFGRW17 - HDLCD PLL external bypass
> ;SCC: 0x700 0x1032F003 ;CFGRW48 - [25:24]Boot CPU [28]Boot
> Cluster (default CA7_0)
> SCC: 0x700 0x0032D003 ;CFGRW48 - [25:24]Boot CPU [28]Boot
> Cluster (default CA7_0)
> ; Bootmon configuration:
> ; [15]: A7 Event stream
> generation (default: disabled)
> ; [14]: A15 Event stream
> generation (default: disabled)
> ; [13]: Power down the
> non-boot cluster (default: disabled)
> ; [12]: Use per-cpu mailboxes
> for power management (default: disabled)
> ; [11]: A15 executes WFEs as
> nops (default: disabled)
> ; [ 4]: Erase UEFI variable
> storage in NOR flash
>
> SCC: 0x400 0x33330c00 ;CFGREG41 - A15 configuration register
> 0 (Default 0x33330c80)
> ; [29:28] SPNIDEN
> ; [25:24] SPIDEN
> ; [21:20] NIDEN
> ; [17:16] DBGEN
> ; [13:12] CFGTE
> ; [9:8] VINITHI_CORE
> ; [7] IMINLN
> ; [3:0] CLUSTER_ID
>
>
> ;Power management interface
>
> SCC: 0xC00 0x00000005 ;Control: [0]PMI_EN [1]DBG_EN [2]SPC_SYSCFG
> SCC: 0xC04 0x000005DC ;Latency in uS max: [15:0]DVFS [31:16]PWRUP
>
>
> On Mon, Oct 21, 2013 at 6:47 PM, Vijay Kilari <vijay.kilari at gmail.com> wrote:
>> Hi Dave Martin,
>>
>> On which kernel base this kexec is tested? is it 3.10 or 3.12?
>> can you please share your git (public) if available?
>>
>> I tested using 3.10 + TC2 patches. However I see sometimes kexec fails
>> to reboot and hangs at very early stage (log below)
>>
>> root at armeb-cortex-a15:/# kexec -e
>> [ 59.311559] Starting new kernel
>>
>> Thanks
>> Vijay
>>
>> Message: 2
>> Date: Tue, 1 Oct 2013 18:15:15 +0100
>> From: Dave Martin <Dave.Martin at arm.com>
>> To: linux-arm-kernel at lists.infradead.org
>> Cc: Nicolas Pitre <nicolas.pitre at linaro.org>, Lorenzo Pieralisi
>> <Lorenzo.Pieralisi at arm.com>, Pawel Moll <Pawel.Moll at arm.com>, Sudeep
>> KarkadaNagesha <Sudeep.KarkadaNagesha at arm.com
>>>, Will Deacon
>> <Will.Deacon at arm.com>, Dave Martin <Dave.Martin at arm.com>
>> Subject: [PATCH v3 0/3] MCPM/TC2 support for CPU powerdown
>> synchronisation
>> Message-ID: <1380647718-9178-1-git-send-email-Dave.Martin at arm.com>
>>
>> This series adds MCPM support for detecting when a CPU is safely powered
>> down, and provides an implementation for TC2.
>>
>> It should be possible to implement the same thing for PSCI using the
>> AFFINITY_INFO call (I need to check the semantics with Charles)
>>
>> This is sufficient to for working kexec with real power management on
>> TC2. To test it, you'll also need:
>>
>> * CONFIG_KEXEC=y
>> * CONFIG_PROC_DEVICE_TREE=y
>> * CONFIG_MCPM=y
>> * CONFIG_ARCH_VEXPRESS_TC2_PM=y
>> * sufficiently new kexec-tools
>> (git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
>> v2.0.4 worked for me)
>>
>> This build on Nico's patch
>> http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=7842/1
>> (MCPM: don't explode if invoked without being initialized first)
>>
>> To prevent CPUs from running off into the weeds across kexec, this
>> series requires Lorenzo's patch
>> http://lists.infradead.org/pipermail/linux-arm-kernel/2013-September/200917.html
>> (arm: vexpress: tc2: fix hotplug/idle/kexec race on cluster power down).
>>
>> Changes since v2:
>>
>> * Return a proper failure code if mcpm_cpu_power_down_finish() is
>> called with no mcpm platforms_ops registered, or a NULL
>> power_down_finish() method. (Thanks again Nico)
>>
>> * Minor refactoring of the loop in tc2_pm_power_down_finish() to
>> avoid the goto.
>>
>> Changes between v1 and v2:
>>
>> * "Fix" erroneous documentation comment by switching to -errno return
>> value convention for power_down_finish(), which is more informative.
>> tc2_pm now returns -ETIMEDOUT on timeout. The return is adapted to
>> bool convention on return from smp_ops.cpu_kill() instead. (Thanks,
>> Nico).
>>
>> * For consistency, BUG_ON out of range cpu or cluster values
>> tc2_pm_power_down_finish(), as for tc2_pm_power_down().
>>
>> Changes between RFC and v1:
>>
>> * Print a big fat warning instead of branching to null if the
>> power_down_finish() method is not supplied by the backend, or not
>> registered.
>>
>> * Add a generous timeout of 1 second for the TC2 implementation.
>>
>> * Relax the polling interval to 10ms for TC2, since the need to poll
>> more than once is rare and this is not a performance-critical path.
>>
>> * Fix some silly typos.
>>
>>
>> Dave Martin (3):
>> ARM: mcpm: Factor out logical-to-physical CPU translation
>> ARM: mcpm: Implement cpu_kill() to synchronise on powerdown
>> ARM: vexpress/TC2: Implement MCPM power_down_finish()
>>
>> arch/arm/common/mcpm_entry.c | 15 +++++++++
>> arch/arm/common/mcpm_platsmp.c | 27 +++++++++++++---
>> arch/arm/include/asm/mcpm.h | 31 ++++++++++++++++++
>> arch/arm/mach-vexpress/spc.c | 39 +++++++++++++++++++++++
>> arch/arm/mach-vexpress/spc.h | 1 +
>> arch/arm/mach-vexpress/tc2_pm.c | 66 ++++++++++++++++++++++++++++++++++++---
>> 6 files changed, 170 insertions(+), 9 deletions(-)
>>
>> --
>> 1.7.9.5
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