Re: [Linux-nvdimm] [PATCH 01/21] e820, efi: add ACPI 6.0 persistent memory types

[Christoph Hellwig <hch@infradead.org>]

On Fri, Apr 17, 2015 at 09:35:19PM -0400, Dan Williams wrote:
> diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
> index c52d7540dc05..cd8b7485e396 100644
> --- a/arch/ia64/kernel/efi.c
> +++ b/arch/ia64/kernel/efi.c
> @@ -1227,6 +1227,7 @@ efi_initialize_iomem_resources(struct resource *code_resource,
>  			case EFI_RUNTIME_SERVICES_CODE:
>  			case EFI_RUNTIME_SERVICES_DATA:
>  			case EFI_ACPI_RECLAIM_MEMORY:
> +			case EFI_PERSISTENT_MEMORY:
>  			default:
>  				name = "reserved";

You probably want pmem as name here..

> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
> index 11cc7d54ec3f..410af501a941 100644
> --- a/arch/x86/kernel/e820.c
> +++ b/arch/x86/kernel/e820.c
> @@ -137,6 +137,8 @@ static void __init e820_print_type(u32 type)
>  	case E820_RESERVED_KERN:
>  		printk(KERN_CONT "usable");
>  		break;
> +	case E820_PMEM:
> +	case E820_PRAM:
>  	case E820_RESERVED:
>  		printk(KERN_CONT "reserved");
>  		break;
> @@ -149,9 +151,6 @@ static void __init e820_print_type(u32 type)
>  	case E820_UNUSABLE:
>  		printk(KERN_CONT "unusable");
>  		break;
> -	case E820_PRAM:
> -		printk(KERN_CONT "persistent (type %u)", type);
> -		break;

Please keep this printk, and add the new E820_PMEM case to it as well.

> +static bool do_mark_busy(u32 type, struct resource *res)
> +{
> +	if (res->start < (1ULL<<20))
> +		return true;
> +
> +	switch (type) {
> +	case E820_RESERVED:
> +	case E820_PRAM:
> +	case E820_PMEM:
> +		return false;
> +	default:
> +		return true;
> +	}
> +}

Please add a comment explaining the choices once you start refactoring
this.  Especially the address check is black magic..