Re: [RESEND PATCH v4] ACPI: Move sdei_init and ghes_init ahead to handle platform errors earlier

[Shuai Xue <xueshuai@linux.alibaba.com>]

Hi Rafeal,

Thank you for your reply.

On 2021/12/18 AM2:17, Rafael J. Wysocki wrote:
> 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/.

OK, I will keep an eye on their response.
I am wondering that do you have any comments for revision?

Thank you.

Best Regrads,
Shuai

>> ---
>>  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
>>