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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Fri, 5 Feb 2021 13:55:33 +0100
Message-ID: <CAJZ5v0hp49Jt6ZWMNUkEOmMST5eM60b8Nzz0wT4w1--zj-KPWw@mail.gmail.com>
Subject: Re: [PATCH v5] ACPI / APEI: fix the regression of synchronous
 external aborts occur in user-mode
To:     tanxiaofei <tanxiaofei@huawei.com>,
        James Morse <james.morse@arm.com>,
        Borislav Petkov <bp@alien8.de>
Cc:     Len Brown <lenb@kernel.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Tony Luck <tony.luck@intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Joerg Roedel <jroedel@suse.de>,
        Peter Zijlstra <peterz@infradead.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linuxarm <linuxarm@huawei.com>
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On Tue, Jan 26, 2021 at 2:32 PM tanxiaofei <tanxiaofei@huawei.com> wrote:
>
> @James
> Hi James, please help to review this patch. Thank you very much. :)

James, Boris, any comments?

> On 2020/12/10 20:09, Xiaofei Tan wrote:
> > After the commit 8fcc4ae6faf8 ("arm64: acpi: Make apei_claim_sea()
> > synchronise with APEI's irq work") applied, do_sea() return directly
> > for user-mode if apei_claim_sea() handled any error record. Therefore,
> > each error record reported by the user-mode SEA must be effectively
> > processed in APEI GHES driver.
> >
> > Currently, GHES driver only processes Memory Error Section.(Ignore PCIe
> > Error Section, as it has nothing to do with SEA). It is not enough.
> > Because ARM Processor Error could also be used for SEA in some hardware
> > platforms, such as Kunpeng9xx series. We can't ask them to switch to
> > use Memory Error Section for two reasons:
> > 1)The server was delivered to customers, and it will introduce
> > compatibility issue.
> > 2)It make sense to use ARM Processor Error Section. Because either
> > cache or memory errors could generate SEA when consumed by a processor.
> >
> > Do memory failure handling for ARM Processor Error Section just like
> > for Memory Error Section.
> >
> > Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
> > ---
> > Changes since v4:
> > - 1. Change the patch name from " ACPI / APEI: do memory failure on the
> > physical address reported by ARM processor error section" to this
> > more proper one.
> > - 2. Add a comment in the code to tell why not filter out corrected
> > error in an uncorrected section.
> >
> > Changes since v3:
> > - Print unhandled error following James Morse's advice.
> >
> > Changes since v2:
> > - Updated commit log
> > ---
> >  drivers/acpi/apei/ghes.c | 76 +++++++++++++++++++++++++++++++++++++-----------
> >  1 file changed, 59 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> > index fce7ade..0893968 100644
> > --- a/drivers/acpi/apei/ghes.c
> > +++ b/drivers/acpi/apei/ghes.c
> > @@ -441,28 +441,35 @@ static void ghes_kick_task_work(struct callback_head *head)
> >       gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, node_len);
> >  }
> >
> > -static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
> > -                                    int sev)
> > +static bool ghes_do_memory_failure(u64 physical_addr, int flags)
> >  {
> >       unsigned long pfn;
> > -     int flags = -1;
> > -     int sec_sev = ghes_severity(gdata->error_severity);
> > -     struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
> >
> >       if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
> >               return false;
> >
> > -     if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
> > -             return false;
> > -
> > -     pfn = mem_err->physical_addr >> PAGE_SHIFT;
> > +     pfn = PHYS_PFN(physical_addr);
> >       if (!pfn_valid(pfn)) {
> >               pr_warn_ratelimited(FW_WARN GHES_PFX
> >               "Invalid address in generic error data: %#llx\n",
> > -             mem_err->physical_addr);
> > +             physical_addr);
> >               return false;
> >       }
> >
> > +     memory_failure_queue(pfn, flags);
> > +     return true;
> > +}
> > +
> > +static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
> > +                                    int sev)
> > +{
> > +     int flags = -1;
> > +     int sec_sev = ghes_severity(gdata->error_severity);
> > +     struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
> > +
> > +     if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
> > +             return false;
> > +
> >       /* iff following two events can be handled properly by now */
> >       if (sec_sev == GHES_SEV_CORRECTED &&
> >           (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
> > @@ -470,14 +477,51 @@ static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
> >       if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
> >               flags = 0;
> >
> > -     if (flags != -1) {
> > -             memory_failure_queue(pfn, flags);
> > -             return true;
> > -     }
> > +     if (flags != -1)
> > +             return ghes_do_memory_failure(mem_err->physical_addr, flags);
> >
> >       return false;
> >  }
> >
> > +static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata, int sev)
> > +{
> > +     struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
> > +     struct cper_arm_err_info *err_info;
> > +     bool queued = false;
> > +     int sec_sev, i;
> > +
> > +     log_arm_hw_error(err);
> > +
> > +     sec_sev = ghes_severity(gdata->error_severity);
> > +     if (sev != GHES_SEV_RECOVERABLE || sec_sev != GHES_SEV_RECOVERABLE)
> > +             return false;
> > +
> > +     err_info = (struct cper_arm_err_info *) (err + 1);
> > +     for (i = 0; i < err->err_info_num; i++, err_info++) {
> > +             bool is_cache = (err_info->type == CPER_ARM_CACHE_ERROR);
> > +             bool has_pa = (err_info->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR);
> > +
> > +             /*
> > +              * The field (err_info->error_info & BIT(26)) is fixed to set to
> > +              * 1 in some old firmware of HiSilicon Kunpeng920. We assume that
> > +              * firmware won't mix corrected errors in an uncorrected section,
> > +              * and don't filter out 'corrected' error here.
> > +              */
> > +             if (!is_cache || !has_pa) {
> > +                     pr_warn_ratelimited(FW_WARN GHES_PFX
> > +                     "Unhandled processor error type %s\n",
> > +                     err_info->type < ARRAY_SIZE(cper_proc_error_type_strs) ?
> > +                     cper_proc_error_type_strs[err_info->type] : "unknown error");
> > +                     continue;
> > +             }
> > +
> > +             if (ghes_do_memory_failure(err_info->physical_fault_addr, 0))
> > +                     queued = true;
> > +     }
> > +
> > +     return queued;
> > +}
> > +
> >  /*
> >   * PCIe AER errors need to be sent to the AER driver for reporting and
> >   * recovery. The GHES severities map to the following AER severities and
> > @@ -605,9 +649,7 @@ static bool ghes_do_proc(struct ghes *ghes,
> >                       ghes_handle_aer(gdata);
> >               }
> >               else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
> > -                     struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
> > -
> > -                     log_arm_hw_error(err);
> > +                     queued = ghes_handle_arm_hw_error(gdata, sev);
> >               } else {
> >                       void *err = acpi_hest_get_payload(gdata);
> >
> >
>