Re: [PATCH 2/7] acpi, apei, ghes: Introduce more generic mechanism to init/deinit GHES error notifications.

[Borislav Petkov <bp@alien8.de>]

On Wed, Apr 09, 2014 at 05:14:30PM +0200, Tomasz Nowicki wrote:
> Init/deinit of GHES error notifications are moved to corresponding
> functions e.g. for SCI ghes_notify_init_sci{sci} and ghes_notify_remove_{sci}
> which in turn are gathered to ghes_notify_tab table.
> ghes_probe and ghes_remove check notification support based on
> function reference pointer in ghes_notify_tab and call it with ghes argument.
> 
> This approach allows us to change address of a given error notification
> init/deinit function call in ghes_notify_tab in runtime. In turn,
> we can avoid #ifdef usage in common code e.g. for NMI which is currently
> supported by x86.
> 
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> ---
>  drivers/acpi/apei/ghes.c |  242 ++++++++++++++++++++++++++++------------------
>  1 file changed, 149 insertions(+), 93 deletions(-)
> 
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index f7edffc..ca8387e 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -148,6 +148,14 @@ static struct irq_work ghes_proc_irq_work;
>  struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
>  static atomic_t ghes_estatus_cache_alloced;
>  
> +struct ghes_notify_setup {
> +	const char *notif_name;
> +	int 	   (*init_call)(struct ghes *ghes);
> +	void 	   (*remove_call)(struct ghes *ghes);
> +};

Please run through checkpatch before submitting:

WARNING: please, no space before tabs
#44: FILE: drivers/acpi/apei/ghes.c:153:
+^Iint ^I   (*init_call)(struct ghes *ghes);$

WARNING: please, no space before tabs
#45: FILE: drivers/acpi/apei/ghes.c:154:
+^Ivoid ^I   (*remove_call)(struct ghes *ghes);$

> +
> +static struct ghes_notify_setup	ghes_notify_tab[];
> +
>  static int ghes_ioremap_init(void)
>  {
>  	ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES,
> @@ -879,10 +887,6 @@ out:
>  	return ret;
>  }
>  
> -static struct notifier_block ghes_notifier_sci = {
> -	.notifier_call = ghes_notify_sci,
> -};
> -
>  static unsigned long ghes_esource_prealloc_size(
>  	const struct acpi_hest_generic *generic)
>  {
> @@ -898,33 +902,151 @@ static unsigned long ghes_esource_prealloc_size(
>  	return prealloc_size;
>  }
>  
> +static int ghes_notify_init_nmi(struct ghes *ghes)
> +{
> +	unsigned long len;
> +
> +	len = ghes_esource_prealloc_size(ghes->generic);
> +	ghes_estatus_pool_expand(len);
> +	mutex_lock(&ghes_list_mutex);
> +	if (list_empty(&ghes_nmi))
> +		register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0, "ghes");
> +	list_add_rcu(&ghes->list, &ghes_nmi);
> +	mutex_unlock(&ghes_list_mutex);
> +
> +	return 0;

Unconditionally returning 0 seems kinda moot. At least
register_nmi_handler() retval could be returned...

...

> +static struct ghes_notify_setup
> +       ghes_notify_tab[ACPI_HEST_NOTIFY_RESERVED] = {
> +               [ACPI_HEST_NOTIFY_POLLED]   = {"POLLED",
> +                                              ghes_notify_init_polled,
> +                                              ghes_notify_remove_polled},
> +               [ACPI_HEST_NOTIFY_EXTERNAL] = {"EXT_IRQ",
> +                                              ghes_notify_init_external,
> +                                              ghes_notify_remove_external},
> +               [ACPI_HEST_NOTIFY_LOCAL]    = {"LOCAL_IRQ", NULL, NULL},
> +               [ACPI_HEST_NOTIFY_SCI]      = {"SCI",
> +                                              ghes_notify_init_sci,
> +                                              ghes_notify_remove_sci},
> +               [ACPI_HEST_NOTIFY_NMI]      = {"NMI",
> +                                              ghes_notify_init_nmi,
> +                                              ghes_notify_remove_nmi},
> +               [ACPI_HEST_NOTIFY_CMCI]     = {"CMCI", NULL, NULL},
> +               [ACPI_HEST_NOTIFY_MCE]      = {"MCE", NULL, NULL},
> +};

I guess you don't need to save the ->notif_name strings but add
a function which maps ACPI_HEST_* to strings => smaller struct
ghes_notify_setup.


> @@ -944,48 +1066,10 @@ static int ghes_probe(struct platform_device *ghes_dev)
>  	if (rc < 0)
>  		goto err;
>  
> -	switch (generic->notify.type) {
> -	case ACPI_HEST_NOTIFY_POLLED:
> -		ghes->timer.function = ghes_poll_func;
> -		ghes->timer.data = (unsigned long)ghes;
> -		init_timer_deferrable(&ghes->timer);
> -		ghes_add_timer(ghes);
> -		break;
> -	case ACPI_HEST_NOTIFY_EXTERNAL:
> -		/* External interrupt vector is GSI */
> -		rc = acpi_gsi_to_irq(generic->notify.vector, &ghes->irq);
> -		if (rc) {
> -			pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
> -			       generic->header.source_id);
> -			goto err_edac_unreg;
> -		}
> -		rc = request_irq(ghes->irq, ghes_irq_func, 0, "GHES IRQ", ghes);
> -		if (rc) {
> -			pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
> -			       generic->header.source_id);
> -			goto err_edac_unreg;
> -		}
> -		break;
> -	case ACPI_HEST_NOTIFY_SCI:
> -		mutex_lock(&ghes_list_mutex);
> -		if (list_empty(&ghes_sci))
> -			register_acpi_hed_notifier(&ghes_notifier_sci);
> -		list_add_rcu(&ghes->list, &ghes_sci);
> -		mutex_unlock(&ghes_list_mutex);
> -		break;
> -	case ACPI_HEST_NOTIFY_NMI:
> -		len = ghes_esource_prealloc_size(generic);
> -		ghes_estatus_pool_expand(len);
> -		mutex_lock(&ghes_list_mutex);
> -		if (list_empty(&ghes_nmi))
> -			register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0,
> -						"ghes");
> -		list_add_rcu(&ghes->list, &ghes_nmi);
> -		mutex_unlock(&ghes_list_mutex);
> -		break;
> -	default:
> -		BUG();

What happened to those BUG() catch-all stoppers?

> -	}
> +	rc = (*ghes_init_call)(ghes);
> +	if (rc)
> +		goto err_edac_unreg;
> +
>  	platform_set_drvdata(ghes_dev, ghes);
>  
>  	return 0;
> @@ -1003,44 +1087,16 @@ static int ghes_remove(struct platform_device *ghes_dev)
>  {
>  	struct ghes *ghes;
>  	struct acpi_hest_generic *generic;
> -	unsigned long len;
> +	void (*ghes_remove_call)(struct ghes *ghes);
>  
>  	ghes = platform_get_drvdata(ghes_dev);
> +	ghes->flags |= GHES_EXITING;
> +
>  	generic = ghes->generic;
> +	ghes_remove_call = ghes_notify_tab[generic->notify.type].remove_call;
>  
> -	ghes->flags |= GHES_EXITING;
> -	switch (generic->notify.type) {
> -	case ACPI_HEST_NOTIFY_POLLED:
> -		del_timer_sync(&ghes->timer);
> -		break;
> -	case ACPI_HEST_NOTIFY_EXTERNAL:
> -		free_irq(ghes->irq, ghes);
> -		break;
> -	case ACPI_HEST_NOTIFY_SCI:
> -		mutex_lock(&ghes_list_mutex);
> -		list_del_rcu(&ghes->list);
> -		if (list_empty(&ghes_sci))
> -			unregister_acpi_hed_notifier(&ghes_notifier_sci);
> -		mutex_unlock(&ghes_list_mutex);
> -		break;
> -	case ACPI_HEST_NOTIFY_NMI:
> -		mutex_lock(&ghes_list_mutex);
> -		list_del_rcu(&ghes->list);
> -		if (list_empty(&ghes_nmi))
> -			unregister_nmi_handler(NMI_LOCAL, "ghes");
> -		mutex_unlock(&ghes_list_mutex);
> -		/*
> -		 * To synchronize with NMI handler, ghes can only be
> -		 * freed after NMI handler finishes.
> -		 */
> -		synchronize_rcu();
> -		len = ghes_esource_prealloc_size(generic);
> -		ghes_estatus_pool_shrink(len);
> -		break;
> -	default:
> -		BUG();
> -		break;

This one too.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--