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References: <20211126070422.73234-1-xueshuai@linux.alibaba.com> <20211216133456.21002-1-xueshuai@linux.alibaba.com>
In-Reply-To: <20211216133456.21002-1-xueshuai@linux.alibaba.com>
From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Fri, 17 Dec 2021 19:17:56 +0100
Message-ID: <CAJZ5v0jOnA90BX0ZisY4Gm4tKTjQMcxOqEOa2FVZsuec0e_mSw@mail.gmail.com>
Subject: Re: [RESEND PATCH v4] ACPI: Move sdei_init and ghes_init ahead to
 handle platform errors earlier
To:     Shuai Xue <xueshuai@linux.alibaba.com>
Cc:     Borislav Petkov <bp@alien8.de>, Tony Luck <tony.luck@intel.com>,
        James Morse <james.morse@arm.com>, Len Brown <lenb@kernel.org>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Bjorn Helgaas <bhelgaas@google.com>,
        luanshi <zhangliguang@linux.alibaba.com>,
        zhuo.song@linux.alibaba.com,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux PCI <linux-pci@vger.kernel.org>,
        Bjorn Helgaas <helgaas@kernel.org>
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Precedence: bulk

On Thu, Dec 16, 2021 at 2:35 PM Shuai Xue <xueshuai@linux.alibaba.com> wrote:
>
> On an ACPI system, ACPI is initialised very early from a subsys_initcall(),
> while SDEI is not ready until a subsys_initcall_sync().
>
> The SDEI driver provides functions (e.g. apei_sdei_register_ghes,
> apei_sdei_unregister_ghes) to register or unregister event callback for
> dispatcher in firmware. When the GHES driver probing, it registers the
> corresponding callback according to the notification type specified by
> GHES. If the GHES notification type is SDEI, the GHES driver will call
> apei_sdei_register_ghes to register event call.
>
> When the firmware emits an event, it migrates the handling of the event
> into the kernel at the registered entry-point __sdei_asm_handler. And
> finally, the kernel will call the registered event callback and return
> status_code to indicate the status of event handling. SDEI_EV_FAILED
> indicates that the kernel failed to handle the event.
>
> Consequently, when an error occurs during kernel booting, the kernel is
> unable to handle and report errors until the GHES driver is initialized by
> device_initcall(), in which the event callback is registered. All errors
> that occurred before GHES initialization are missed and there is no chance
> to report and find them again.
>
> From commit e147133a42cb ("ACPI / APEI: Make hest.c manage the estatus
> memory pool") was merged, ghes_init() relies on acpi_hest_init() to manage
> the estatus memory pool. On the other hand, ghes_init() relies on
> sdei_init() to detect the SDEI version and the framework for registering
> and unregistering events. By the way, I don't figure out why acpi_hest_init
> is called in acpi_pci_root_init, it don't rely on any other thing. May it
> could be moved further, following acpi_iort_init in acpi_init.
>
> sdei_init() relies on ACPI table which is initialized subsys_initcall():
> acpi_init(), acpi_bus_init(), acpi_load_tables(), acpi_tb_laod_namespace().
> May it should be also moved further, after acpi_load_tables.
>
> In this patch, move sdei_init and ghes_init as far ahead as possible, right
> after acpi_hest_init().
>
> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>

This needs ACKs from Bjorn and Boris/Tony/James/.

> ---
>  drivers/acpi/apei/ghes.c    | 18 ++++++++----------
>  drivers/acpi/pci_root.c     |  5 ++++-
>  drivers/firmware/arm_sdei.c | 13 ++-----------
>  include/acpi/apei.h         |  2 ++
>  include/linux/arm_sdei.h    |  2 ++
>  5 files changed, 18 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index 0c8330ed1ffd..b11e46fb4b3d 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -1457,27 +1457,26 @@ static struct platform_driver ghes_platform_driver = {
>         .remove         = ghes_remove,
>  };
>
> -static int __init ghes_init(void)
> +void __init ghes_init(void)
>  {
>         int rc;
>
>         if (acpi_disabled)
> -               return -ENODEV;
> +               return;
>
>         switch (hest_disable) {
>         case HEST_NOT_FOUND:
> -               return -ENODEV;
> +               pr_info(GHES_PFX "HEST is not found!\n");
> +               return;
>         case HEST_DISABLED:
>                 pr_info(GHES_PFX "HEST is not enabled!\n");
> -               return -EINVAL;
> +               return;
>         default:
>                 break;
>         }
>
> -       if (ghes_disable) {
> +       if (ghes_disable)
>                 pr_info(GHES_PFX "GHES is not enabled!\n");
> -               return -EINVAL;
> -       }
>
>         ghes_nmi_init_cxt();
>
> @@ -1495,8 +1494,7 @@ static int __init ghes_init(void)
>         else
>                 pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
>
> -       return 0;
> +       return;
>  err:
> -       return rc;
> +       ghes_disable = 1;
>  }
> -device_initcall(ghes_init);
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index ab2f7dfb0c44..1260bb556184 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -23,7 +23,7 @@
>  #include <linux/dmi.h>
>  #include <linux/platform_data/x86/apple.h>
>  #include <acpi/apei.h> /* for acpi_hest_init() */
> -
> +#include <linux/arm_sdei.h> /* for sdei_init() */
>  #include "internal.h"
>
>  #define ACPI_PCI_ROOT_CLASS            "pci_bridge"
> @@ -946,6 +946,9 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
>  void __init acpi_pci_root_init(void)
>  {
>         acpi_hest_init();
> +       sdei_init();
> +       ghes_init();
> +
>         if (acpi_pci_disabled)
>                 return;
>
> diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
> index a7e762c352f9..1e1a51510e83 100644
> --- a/drivers/firmware/arm_sdei.c
> +++ b/drivers/firmware/arm_sdei.c
> @@ -1059,14 +1059,14 @@ static bool __init sdei_present_acpi(void)
>         return true;
>  }
>
> -static int __init sdei_init(void)
> +void __init sdei_init(void)
>  {
>         struct platform_device *pdev;
>         int ret;
>
>         ret = platform_driver_register(&sdei_driver);
>         if (ret || !sdei_present_acpi())
> -               return ret;
> +               return;
>
>         pdev = platform_device_register_simple(sdei_driver.driver.name,
>                                                0, NULL, 0);
> @@ -1076,17 +1076,8 @@ static int __init sdei_init(void)
>                 pr_info("Failed to register ACPI:SDEI platform device %d\n",
>                         ret);
>         }
> -
> -       return ret;
>  }
>
> -/*
> - * On an ACPI system SDEI needs to be ready before HEST:GHES tries to register
> - * its events. ACPI is initialised from a subsys_initcall(), GHES is initialised
> - * by device_initcall(). We want to be called in the middle.
> - */
> -subsys_initcall_sync(sdei_init);
> -
>  int sdei_event_handler(struct pt_regs *regs,
>                        struct sdei_registered_event *arg)
>  {
> diff --git a/include/acpi/apei.h b/include/acpi/apei.h
> index ece0a8af2bae..7dbd6363fda7 100644
> --- a/include/acpi/apei.h
> +++ b/include/acpi/apei.h
> @@ -27,8 +27,10 @@ extern int hest_disable;
>  extern int erst_disable;
>  #ifdef CONFIG_ACPI_APEI_GHES
>  extern bool ghes_disable;
> +void __init ghes_init(void);
>  #else
>  #define ghes_disable 1
> +static inline void ghes_init(void) { return; }
>  #endif
>
>  #ifdef CONFIG_ACPI_APEI
> diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h
> index 0a241c5c911d..9c987188b692 100644
> --- a/include/linux/arm_sdei.h
> +++ b/include/linux/arm_sdei.h
> @@ -46,9 +46,11 @@ int sdei_unregister_ghes(struct ghes *ghes);
>  /* For use by arch code when CPU hotplug notifiers are not appropriate. */
>  int sdei_mask_local_cpu(void);
>  int sdei_unmask_local_cpu(void);
> +void __init sdei_init(void);
>  #else
>  static inline int sdei_mask_local_cpu(void) { return 0; }
>  static inline int sdei_unmask_local_cpu(void) { return 0; }
> +static inline void sdei_init(void) { return ; }
>  #endif /* CONFIG_ARM_SDE_INTERFACE */
>
>
> --
> 2.20.1.12.g72788fdb
>