Re: [PATCH v5 08/14] efi: export efi runtime memory mapping to sysfs

[Dave Young]

On 12/13/13 at 12:30pm, Matt Fleming wrote:
> On Fri, 13 Dec, at 03:26:00PM, Dave Young wrote:
> > On 12/12/13 at 09:53pm, Borislav Petkov wrote:
> > > On Thu, Dec 12, 2013 at 10:36:17AM +0800, Dave Young wrote:
> > > > Sorry that I forgot to explain this in changelog, should ask you before.
> > > > 
> > > > I did try moving it to efisubsys_init but it need add extern declaration
> > > 
> > > So what? Add it.
> > > 
> > > > for efi_runtime_map_init. Since link order will ensure it being called after
> > > > efisubsys_init I think it's fine with this static function.
> > > 
> > > This is actually exactly the reason why it shouldn't be another
> > > subsys_initcall() if it can be helped. People would need to go have a
> > > look at drivers/firmware/efi/Makefile to realize that the link order is
> > > ok.
> > > 
> > > And, this is prone to future breakage if people go and move code around
> > > and thereby change the link order.
> > > 
> > > Please call efi_runtime_map_init from efisubsys_init.
> > 
> > After moving to efisubsys_init, the code will looks like below, because

Will call it in efi_subsys_init as what I replied previously.

> > the funtion only is used in drivers/firmware/efi/efi.c thus I can not
> > add a blank function in #else section in the efi.h header file. Creating
> > another header file for this one function looks bad to me.
> 
> I agree with Borislav that this should be invoked from efisubsys_init().
> Also Dave, there's nothing inherently x86-specific about runtime-map.c -
> we've been trying not to dump arch-specific code in
> drivers/firmware/efi/.
> 
> How about something like this, just to give you an idea? This would
> allow the ARM/ia64 folks to enable this code if they want at some later
> date. But more than that, it makes the code more self-contained and uses
> some real interfaces instead of relying on global variables,
> 
> (not compile tested)

Thanks for the good idea, will tune and test the code.

> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 94a1cbcf6e2e..f45ea41deae0 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -76,8 +76,8 @@ static __initdata efi_config_table_type_t arch_tables[] = {
>  	{NULL_GUID, NULL, NULL},
>  };
>  
> -void *efi_runtime_map;
> -int nr_efi_runtime_map;
> +static void *efi_runtime_map;
> +static int nr_efi_runtime_map;
>  static u64 efi_setup; /* efi setup_data physical address */
>  
>  /*
> @@ -1084,6 +1084,9 @@ void __init efi_enter_virtual_mode(void)
>  		}
>  	}
>  
> +	efi_runtime_map_setup(efi_runtime_map, nr_efi_runtime_map,
> +			      boot_params.efi_info.efi_memdesc_size);
> +
>  	BUG_ON(!efi.systab);
>  
>  	efi_setup_page_tables();
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 0a288e306252..9870eb55d0e5 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -38,8 +38,7 @@ struct efi __read_mostly efi = {
>  };
>  EXPORT_SYMBOL(efi);
>  
> -struct kobject *efi_kobj;
> -EXPORT_SYMBOL_GPL(efi_kobj);
> +static struct kobject *efi_kobj;
>  static struct kobject *efivars_kobj;
>  
>  /*
> @@ -176,6 +175,8 @@ static int __init efisubsys_init(void)
>  		goto err_remove_group;
>  	}
>  
> +	efi_runtime_map_init(efi_kobj);
> +
>  	return 0;
>  
>  err_remove_group:
> diff --git a/drivers/firmware/efi/runtime-map.c b/drivers/firmware/efi/runtime-map.c
> index e5e998494d8a..ef9631e9c03e 100644
> --- a/drivers/firmware/efi/runtime-map.c
> +++ b/drivers/firmware/efi/runtime-map.c
> @@ -14,6 +14,10 @@
>  
>  #include <asm/setup.h>
>  
> +static void *efi_runtime_map;
> +static int nr_efi_runtime_map;
> +static u32 efi_memdesc_size;
> + 
>  struct efi_runtime_map_entry {
>  	efi_memory_desc_t md;
>  	struct kobject kobj;   /* kobject for each entry */
> @@ -105,7 +109,6 @@ static struct efi_runtime_map_entry *add_sysfs_runtime_map_entry(int nr)
>  {
>  	int ret;
>  	struct efi_runtime_map_entry *entry;
> -	struct efi_info *e = &boot_params.efi_info;
>  
>  	if (!map_kset) {
>  		map_kset = kset_create_and_add("runtime-map", NULL,
> @@ -120,7 +123,7 @@ static struct efi_runtime_map_entry *add_sysfs_runtime_map_entry(int nr)
>  		return entry;
>  	}
>  
> -	memcpy(&entry->md, efi_runtime_map + nr * e->efi_memdesc_size,
> +	memcpy(&entry->md, efi_runtime_map + nr * efi_memdesc_size,
>  	       sizeof(efi_memory_desc_t));
>  
>  	kobject_init(&entry->kobj, &map_ktype);
> @@ -135,7 +138,14 @@ static struct efi_runtime_map_entry *add_sysfs_runtime_map_entry(int nr)
>  	return entry;
>  }
>  
> -static int __init efi_runtime_map_init(void)
> +int efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size)
> +{
> +	efi_runtime_map = map;
> +	nr_efi_runtime_map = nr_entries;
> +	efi_memdesc_size = desc_size;
> +}
> +
> +int __init efi_runtime_map_init(struct kobject *efi_kobj)
>  {
>  	int i, j, ret = 0;
>  	struct efi_runtime_map_entry *entry;
> @@ -172,5 +182,3 @@ out_add_entry:
>  out:
>  	return ret;
>  }
> -
> -subsys_initcall(efi_runtime_map_init);
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 4f1651d303b8..47e067044054 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -873,9 +873,8 @@ int efivars_sysfs_init(void);
>  #endif /* CONFIG_EFI_VARS */
>  
>  #ifdef CONFIG_EFI_RUNTIME_MAP
> -extern void *efi_runtime_map;
> -extern int nr_efi_runtime_map;
> -extern struct kobject *efi_kobj;
> +int efi_runtime_map_init(struct kobject *);
> +int efi_runtime_map_setup(void *, int, u32);
>  #endif
>  
>  #endif /* _LINUX_EFI_H */
> 
> -- 
> Matt Fleming, Intel Open Source Technology Center
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