From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Baicar, Tyler" Subject: Re: [PATCH V15 06/11] acpi: apei: handle SEA notification type for ARMv8 Date: Tue, 25 Apr 2017 11:41:39 -0600 Message-ID: <6d7249d3-e0b2-afa7-b5fa-8e85c40d8a13@codeaurora.org> References: <1492556723-9189-1-git-send-email-tbaicar@codeaurora.org> <1492556723-9189-7-git-send-email-tbaicar@codeaurora.org> <20170425172154.ggg56j52inf3522e@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170425172154.ggg56j52inf3522e@pd.tnic> Content-Language: en-US Sender: linux-acpi-owner@vger.kernel.org To: Borislav Petkov Cc: christoffer.dall@linaro.org, marc.zyngier@arm.com, pbonzini@redhat.com, rkrcmar@redhat.com, linux@armlinux.org.uk, catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, matt@codeblueprint.co.uk, robert.moore@intel.com, lv.zheng@intel.com, nkaje@codeaurora.org, zjzhang@codeaurora.org, mark.rutland@arm.com, james.morse@arm.com, akpm@linux-foundation.org, eun.taik.lee@samsung.com, sandeepa.s.prabhu@gmail.com, labbott@redhat.com, shijie.huang@arm.com, rruigrok@codeaurora.org, paul.gortmaker@windriver.com, tn@semihalf.com, fu.wei@linaro.org, rostedt@goodmis.org, bristot@redhat.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-efi@vger.kernel.org List-Id: linux-efi@vger.kernel.org On 4/25/2017 11:21 AM, Borislav Petkov wrote: > On Tue, Apr 18, 2017 at 05:05:18PM -0600, Tyler Baicar wrote: >> ARM APEI extension proposal added SEA (Synchronous External Abort) >> notification type for ARMv8. >> Add a new GHES error source handling function for SEA. If an error >> source's notification type is SEA, then this function can be registered >> into the SEA exception handler. That way GHES will parse and report >> SEA exceptions when they occur. >> An SEA can interrupt code that had interrupts masked and is treated as >> an NMI. To aid this the page of address space for mapping APEI buffers >> while in_nmi() is always reserved, and ghes_ioremap_pfn_nmi() is >> changed to use the helper methods to find the prot_t to map with in >> the same way as ghes_ioremap_pfn_irq(). > ... > >> @@ -518,6 +520,17 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) >> pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n", >> inf->name, esr, addr); >> >> + /* >> + * Synchronous aborts may interrupt code which had interrupts masked. >> + * Before calling out into the wider kernel tell the interested >> + * subsystems. >> + */ >> + if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) { >> + nmi_enter(); >> + ghes_notify_sea(); >> + nmi_exit(); >> + } > Well, the other GHES notification methods use a notifier: > ghes_notify_sci, ghes_notify_nmi. You probably should do that too > instead of calling straight into a driver from arch code. I originally had this as a notifier, but Will requested to remove the notifier. That conversation is here: https://lkml.org/lkml/2017/1/18/1018 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.