From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Baicar, Tyler" Subject: Re: [PATCH V17 01/11] acpi: apei: read ack upon ghes record consumption Date: Fri, 30 Jun 2017 10:47:17 -0600 Message-ID: References: <1495225933-4410-1-git-send-email-tbaicar@codeaurora.org> <1495225933-4410-2-git-send-email-tbaicar@codeaurora.org> <20170630101043.GZ658@rric.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170630101043.GZ658-vWBEXY7mpu582hYKe6nXyg@public.gmane.org> Content-Language: en-US Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Robert Richter Cc: christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, pbonzini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, rkrcmar-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, catalin.marinas-5wv7dgnIgG8@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org, lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org, robert.moore-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, lv.zheng-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, nkaje-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, zjzhang-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, james.morse-5wv7dgnIgG8@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, eun.taik.lee-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, sandeepa.s.prabhu-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, labbott-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, shijie.huang-5wv7dgnIgG8@public.gmane.org, rruigrok-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org, tn-nYOzD4b6Jr9Wk0Htik3J/w@public.gmane.org, fu.wei-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org, bristot-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, kvmarm-FPEHb7Xf0XXUo1n7N8X6UoWGPAHP3yOg@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-acpi@vger.kernel.org On 6/30/2017 4:10 AM, Robert Richter wrote: > Tyler, > > On 19.05.17 14:32:03, Tyler Baicar wrote: >> A RAS (Reliability, Availability, Serviceability) controller >> may be a separate processor running in parallel with OS >> execution, and may generate error records for consumption by >> the OS. If the RAS controller produces multiple error records, >> then they may be overwritten before the OS has consumed them. >> >> The Generic Hardware Error Source (GHES) v2 structure >> introduces the capability for the OS to acknowledge the >> consumption of the error record generated by the RAS >> controller. A RAS controller supporting GHESv2 shall wait for >> the acknowledgment before writing a new error record, thus >> eliminating the race condition. >> >> Add support for parsing of GHESv2 sub-tables as well. >> >> Signed-off-by: Tyler Baicar >> CC: Jonathan (Zhixiong) Zhang >> Reviewed-by: James Morse >> --- >> drivers/acpi/apei/ghes.c | 59 +++++++++++++++++++++++++++++++++++++++++++++--- >> drivers/acpi/apei/hest.c | 7 ++++-- >> include/acpi/ghes.h | 5 +++- >> 3 files changed, 65 insertions(+), 6 deletions(-) >> static int ghes_proc(struct ghes *ghes) >> { >> int rc; >> @@ -661,6 +704,16 @@ static int ghes_proc(struct ghes *ghes) >> ghes_estatus_cache_add(ghes->generic, ghes->estatus); >> } >> ghes_do_proc(ghes, ghes->estatus); >> + >> + /* >> + * GHESv2 type HEST entries introduce support for error acknowledgment, >> + * so only acknowledge the error if this support is present. >> + */ >> + if (is_hest_type_generic_v2(ghes)) { >> + rc = ghes_ack_error(ghes->generic_v2); >> + if (rc) >> + return rc; >> + } >> out: >> ghes_clear_estatus(ghes); >> return rc; > was there any specific reason why the ack is sent before clearing the > block status? Spec says the ack should be sent at last. > > Also, the block is never cleared if ghes_ack_error() returns an error. > IMO we should fall through and clear the block status (this will > change anyway if the bloc status is cleared first). Hello Robert, Thank you for pointing this out. I will send a patch to move the ack after the ghes_clear_estatus. This is probably the right thing to do since right now if the FW populates an invalid estatus, we will fail to read the estatus, jump to 'out:', and never send the ack. 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.