From mboxrd@z Thu Jan 1 00:00:00 1970 From: tbaicar@codeaurora.org (Baicar, Tyler) Date: Wed, 18 Jan 2017 15:53:24 -0700 Subject: [PATCH V7 04/10] arm64: exception: handle Synchronous External Abort In-Reply-To: <20170117102753.GA27328@arm.com> References: <1484244924-24786-1-git-send-email-tbaicar@codeaurora.org> <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> <20170116115309.GE1510@arm.com> <0ca6c70e-6033-4cca-8833-15cb8573a939@codeaurora.org> <20170117102753.GA27328@arm.com> Message-ID: <93ba3d26-a80e-5686-0b13-26bc7df0ee6e@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 1/17/2017 3:27 AM, Will Deacon wrote: > On Mon, Jan 16, 2017 at 01:09:22PM -0700, Baicar, Tyler wrote: >> On 1/16/2017 4:53 AM, Will Deacon wrote: >>> On Thu, Jan 12, 2017 at 11:15:18AM -0700, Tyler Baicar wrote: >>>> SEA exceptions are often caused by an uncorrected hardware >>>> error, and are handled when data abort and instruction abort >>>> exception classes have specific values for their Fault Status >>>> Code. >>>> When SEA occurs, before killing the process, go through >>>> the handlers registered in the notification list. >>>> Update fault_info[] with specific SEA faults so that the >>>> new SEA handler is used. >>>> >>>> Signed-off-by: Tyler Baicar >>>> Signed-off-by: Jonathan (Zhixiong) Zhang >>>> Signed-off-by: Naveen Kaje >>>> --- >>>> arch/arm64/include/asm/system_misc.h | 13 ++++++++ >>>> arch/arm64/mm/fault.c | 58 +++++++++++++++++++++++++++++------- >>>> 2 files changed, 61 insertions(+), 10 deletions(-) >>>> >>>> diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h >>>> index 57f110b..e7f3440 100644 >>>> --- a/arch/arm64/include/asm/system_misc.h >>>> +++ b/arch/arm64/include/asm/system_misc.h >>>> @@ -64,4 +64,17 @@ extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); >>>> #endif /* __ASSEMBLY__ */ >>>> +/* >>>> + * The functions below are used to register and unregister callbacks >>>> + * that are to be invoked when a Synchronous External Abort (SEA) >>>> + * occurs. An SEA is raised by certain fault status codes that have >>>> + * either data or instruction abort as the exception class, and >>>> + * callbacks may be registered to parse or handle such hardware errors. >>>> + * >>>> + * Registered callbacks are run in an interrupt/atomic context. They >>>> + * are not allowed to block or sleep. >>>> + */ >>>> +int register_sea_notifier(struct notifier_block *nb); >>>> +void unregister_sea_notifier(struct notifier_block *nb); >>> I still don't understand why you need notifiers for this. You register >>> precisely one hook in the series. >> I didn't see a response to my last comment on the previous series so I just >> left it in for this series. >> The notifier usage is consistent with the GHES code for SCI errors which are >> also only used a single >> time in the code. If you think making the call directly is a better option I >> will remove the notifiers. > Yes, please. It's easy to add the notifier infrastructure back if/when it's > actually needed and I don't see why the low-level fault dispatching needs to > be consistent with the GHES/SCI code. > > Will Sounds good, I will remove the notifier in the next patchset. Thanks, Tyler -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.