RE: 回复: [PATCH] ACPI: APEI: move edac_init ahead of ghes platform drv register

[Justin He]

Hi Borislav

> -----Original Message-----
> From: Borislav Petkov <bp@xxxxxxxxx>
> Sent: Wednesday, August 10, 2022 2:46 AM
> To: Justin He <Justin.He@xxxxxxx>
> Cc: Kani, Toshi <toshi.kani@xxxxxxx>; Rafael J. Wysocki <rafael@xxxxxxxxxx>;
> Len Brown <lenb@xxxxxxxxxx>; James Morse <James.Morse@xxxxxxx>;
> Tony Luck <tony.luck@xxxxxxxxx>; Mauro Carvalho Chehab
> <mchehab@xxxxxxxxxx>; Robert Richter <rric@xxxxxxxxxx>; Shuai Xue
> <xueshuai@xxxxxxxxxxxxxxxxx>; Jarkko Sakkinen <jarkko@xxxxxxxxxx>; ACPI
> Devel Maling List <linux-acpi@xxxxxxxxxxxxxxx>; Linux Kernel Mailing List
> <linux-kernel@xxxxxxxxxxxxxxx>; open list:EDAC-CORE
> <linux-edac@xxxxxxxxxxxxxxx>
> Subject: Re: 回复: [PATCH] ACPI: APEI: move edac_init ahead of ghes
> platform drv register
> 
[...]
> ---
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index
> d91ad378c00d..0919317b8313 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -118,6 +118,9 @@ module_param_named(disable, ghes_disable, bool,
> 0);  static LIST_HEAD(ghes_hed);  static DEFINE_MUTEX(ghes_list_mutex);
> 
> +static LIST_HEAD(ghes_devs);
> +static DEFINE_MUTEX(ghes_devs_mutex);
> +
>  /*
>   * Because the memory area used to transfer hardware error information
>   * from BIOS to Linux can be determined only in NMI, IRQ or timer @@
> -1376,7 +1379,11 @@ static int ghes_probe(struct platform_device
> *ghes_dev)
> 
>  	platform_set_drvdata(ghes_dev, ghes);
> 
> -	ghes_edac_register(ghes, &ghes_dev->dev);
> +	ghes->dev = &ghes_dev->dev;
> +
> +	mutex_lock(&ghes_devs_mutex);
> +	list_add_tail(&ghes->elist, &ghes_devs);
> +	mutex_unlock(&ghes_devs_mutex);
> 
>  	/* Handle any pending errors right away */
>  	spin_lock_irqsave(&ghes_notify_lock_irq, flags); @@ -1440,8 +1447,6
> @@ static int ghes_remove(struct platform_device *ghes_dev)
> 
>  	ghes_fini(ghes);
> 
> -	ghes_edac_unregister(ghes);
> -
>  	kfree(ghes);
> 
>  	platform_set_drvdata(ghes_dev, NULL);
> @@ -1497,3 +1502,25 @@ void __init acpi_ghes_init(void)
>  	else
>  		pr_info(GHES_PFX "Failed to enable APEI firmware first
> mode.\n");  }
> +
> +/*
> + * Known x86 systems that prefer GHES error reporting:
> + */
> +static struct acpi_platform_list plat_list[] = {
> +	{"HPE   ", "Server  ", 0, ACPI_SIG_FADT, all_versions},
> +	{ } /* End */
> +};
> +
> +struct list_head *ghes_get_devices(bool force) {
> +	int idx = -1;
> +
> +	if (IS_ENABLED(CONFIG_X86)) {
> +		idx = acpi_match_platform_list(plat_list);
> +		if (idx < 0 && !force)
> +			return NULL;
> +	}
> +
> +	return &ghes_devs;
> +}
> +EXPORT_SYMBOL_GPL(ghes_get_devices);
> diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig index
> 17562cf1fe97..df45db81858b 100644
> --- a/drivers/edac/Kconfig
> +++ b/drivers/edac/Kconfig
> @@ -53,8 +53,8 @@ config EDAC_DECODE_MCE
>  	  has been initialized.
> 
>  config EDAC_GHES
> -	bool "Output ACPI APEI/GHES BIOS detected errors via EDAC"
> -	depends on ACPI_APEI_GHES && (EDAC=y)
> +	tristate "Output ACPI APEI/GHES BIOS detected errors via EDAC"
> +	depends on ACPI_APEI_GHES
>  	select UEFI_CPER
>  	help
>  	  Not all machines support hardware-driven error report. Some of those
> diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c index
> c8fa7dcfdbd0..da6d1a9e107d 100644
> --- a/drivers/edac/ghes_edac.c
> +++ b/drivers/edac/ghes_edac.c
> @@ -59,6 +59,8 @@ module_param(force_load, bool, 0);
> 
>  static bool system_scanned;
> 
> +static struct list_head *ghes_devs;
> +
>  /* Memory Device - Type 17 of SMBIOS spec */  struct memdev_dmi_entry
> {
>  	u8 type;
> @@ -376,34 +378,15 @@ void ghes_edac_report_mem_error(int sev, struct
> cper_sec_mem_err *mem_err)
>  	spin_unlock_irqrestore(&ghes_lock, flags);  }
> 
> -/*
> - * Known systems that are safe to enable this module.
> - */
> -static struct acpi_platform_list plat_list[] = {
> -	{"HPE   ", "Server  ", 0, ACPI_SIG_FADT, all_versions},
> -	{ } /* End */
> -};
> -
> -int ghes_edac_register(struct ghes *ghes, struct device *dev)
> +static int ghes_edac_register(struct device *dev)
>  {
>  	bool fake = false;
>  	struct mem_ctl_info *mci;
>  	struct ghes_pvt *pvt;
>  	struct edac_mc_layer layers[1];
>  	unsigned long flags;
> -	int idx = -1;
>  	int rc = 0;
> 
> -	if (IS_ENABLED(CONFIG_X86)) {
> -		/* Check if safe to enable on this system */
> -		idx = acpi_match_platform_list(plat_list);
> -		if (!force_load && idx < 0)
> -			return -ENODEV;
> -	} else {
> -		force_load = true;
> -		idx = 0;
> -	}
> -
>  	/* finish another registration/unregistration instance first */
>  	mutex_lock(&ghes_reg_mutex);
> 
> @@ -447,7 +430,7 @@ int ghes_edac_register(struct ghes *ghes, struct
> device *dev)
>  		pr_info("This system has a very crappy BIOS: It doesn't even list the
> DIMMS.\n");
>  		pr_info("Its SMBIOS info is wrong. It is doubtful that the error report
> would\n");
>  		pr_info("work on such system. Use this driver with caution\n");
> -	} else if (idx < 0) {
> +	} else if (force_load) {
>  		pr_info("This EDAC driver relies on BIOS to enumerate memory and
> get error reports.\n");
>  		pr_info("Unfortunately, not all BIOSes reflect the memory layout
> correctly.\n");
>  		pr_info("So, the end result of using this driver varies from vendor to
> vendor.\n"); @@ -517,7 +500,7 @@ int ghes_edac_register(struct ghes *ghes,
> struct device *dev)
>  	return rc;
>  }
> 
> -void ghes_edac_unregister(struct ghes *ghes)
> +static void ghes_edac_unregister(struct ghes *ghes)
>  {
>  	struct mem_ctl_info *mci;
>  	unsigned long flags;
> @@ -551,3 +534,30 @@ void ghes_edac_unregister(struct ghes *ghes)
>  unlock:
>  	mutex_unlock(&ghes_reg_mutex);
>  }
> +
> +static int __init ghes_edac_init(void)
> +{
> +	struct ghes *g, *g_tmp;
> +
> +	ghes_devs = ghes_get_devices(force_load);
> +	if (ghes_devs)
Should it be changed to if(!ghes_devs) ?
Otherwise, this ghes_edac_init() on Arm will always return with ENODEV
because ! ghes_get_devices().

What do you think of it?

--
Cheers,
Justin (Jia He)


> +		return -ENODEV;
> +
> +	list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
> +		ghes_edac_register(g->dev);
> +	}
> +
> +	return 0;
> +}
> +module_init(ghes_edac_init);
> +
> +static void __exit ghes_edac_exit(void) {
> +	struct ghes *g, *g_tmp;
> +
> +
> +	list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
> +		ghes_edac_unregister(g);
> +	}
> +}
> +module_exit(ghes_edac_exit);
> diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h index
> 34fb3431a8f3..f39b75c3f9c6 100644
> --- a/include/acpi/ghes.h
> +++ b/include/acpi/ghes.h
> @@ -27,6 +27,8 @@ struct ghes {
>  		struct timer_list timer;
>  		unsigned int irq;
>  	};
> +	struct device *dev;
> +	struct list_head elist;
>  };
> 
>  struct ghes_estatus_node {
> @@ -69,35 +71,13 @@ int ghes_register_vendor_record_notifier(struct
> notifier_block *nb);
>   * @nb: pointer to the notifier_block structure of the vendor record handler.
>   */
>  void ghes_unregister_vendor_record_notifier(struct notifier_block *nb);
> +struct list_head *ghes_get_devices(bool force); #else static inline
> +struct list_head *ghes_get_devices(bool force) { return NULL; }
>  #endif
> 
>  int ghes_estatus_pool_init(int num_ghes);
> 
> -/* From drivers/edac/ghes_edac.c */
> -
> -#ifdef CONFIG_EDAC_GHES
> -void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err
> *mem_err);
> -
> -int ghes_edac_register(struct ghes *ghes, struct device *dev);
> -
> -void ghes_edac_unregister(struct ghes *ghes);
> -
> -#else
> -static inline void ghes_edac_report_mem_error(int sev,
> -				       struct cper_sec_mem_err *mem_err)
> -{
> -}
> -
> -static inline int ghes_edac_register(struct ghes *ghes, struct device *dev) -{
> -	return -ENODEV;
> -}
> -
> -static inline void ghes_edac_unregister(struct ghes *ghes) -{ -} -#endif
> -
>  static inline int acpi_hest_get_version(struct acpi_hest_generic_data *gdata)
> {
>  	return gdata->revision >> 8;
> 
> --
> Regards/Gruss,
>     Boris.
> 
> https://people.kernel.org/tglx/notes-about-netiquette