Re: [Linux-nvdimm] [PATCH 3/3] x86: add support for the non-standard protected e820 type

[Dan Williams <dan.j.williams@intel.com>]

On Wed, Mar 25, 2015 at 9:04 AM, Christoph Hellwig <hch@lst.de> wrote:
> Various recent bioses support NVDIMMs or ADR using a non-standard
> e820 memory type, and Intel supplied reference Linux code using this
> type to various vendors.
>
> Wire this e820 table type up to export platform devices for the pmem
> driver so that we can use it in Linux, and also provide a memmap=
> argument to manually tag memory as protected, which can be used
> if the bios doesn't use the standard nonstandard interface, or
> we just want to test the pmem driver with regular memory.
>
> Based on an earlier patch from Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
[..]
> +static __init int register_pmem_devices(void)
> +{
> +       int i;
> +
> +       for (i = 0; i < e820.nr_map; i++) {
> +               struct e820entry *ei = &e820.map[i];
> +
> +               if (ei->type == E820_PROTECTED_KERN) {
> +                       struct resource res = {
> +                               .flags  = IORESOURCE_MEM,
> +                               .start  = ei->addr,
> +                               .end    = ei->addr + ei->size - 1,
> +                       };
> +                       register_pmem_device(&res);
> +               }
> +       }
> +
> +       return 0;
> +}

Aside from the s/E820_PROTECTED_KERN/E820_PMEM/ suggestion this looks
ok to me.  The "vaporware" new way can be a superset of this
mechanism.