Re: [PATCH v4 1/2] memremap: rename MEMORY_DEVICE_DEVDAX to MEMORY_DEVICE_GENERIC

[David Hildenbrand <david@xxxxxxxxxx>]

On 11.08.20 11:44, Roger Pau Monne wrote:
> This is in preparation for the logic behind MEMORY_DEVICE_DEVDAX also
> being used by non DAX devices.
> 
> No functional change intended.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> ---
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
> Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Jason Gunthorpe <jgg@xxxxxxxx>
> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx>
> Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
> Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> Cc: linux-nvdimm@xxxxxxxxxxxx
> Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> ---
>  drivers/dax/device.c     | 2 +-
>  include/linux/memremap.h | 9 ++++-----
>  mm/memremap.c            | 2 +-
>  3 files changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/dax/device.c b/drivers/dax/device.c
> index 4c0af2eb7e19..1e89513f3c59 100644
> --- a/drivers/dax/device.c
> +++ b/drivers/dax/device.c
> @@ -429,7 +429,7 @@ int dev_dax_probe(struct device *dev)
>               return -EBUSY;
>       }
>  
> -     dev_dax->pgmap.type = MEMORY_DEVICE_DEVDAX;
> +     dev_dax->pgmap.type = MEMORY_DEVICE_GENERIC;
>       addr = devm_memremap_pages(dev, &dev_dax->pgmap);
>       if (IS_ERR(addr))
>               return PTR_ERR(addr);
> diff --git a/include/linux/memremap.h b/include/linux/memremap.h
> index 5f5b2df06e61..e5862746751b 100644
> --- a/include/linux/memremap.h
> +++ b/include/linux/memremap.h
> @@ -46,11 +46,10 @@ struct vmem_altmap {
>   * wakeup is used to coordinate physical address space management (ex:
>   * fs truncate/hole punch) vs pinned pages (ex: device dma).
>   *
> - * MEMORY_DEVICE_DEVDAX:
> + * MEMORY_DEVICE_GENERIC:
>   * Host memory that has similar access semantics as System RAM i.e. DMA
> - * coherent and supports page pinning. In contrast to
> - * MEMORY_DEVICE_FS_DAX, this memory is access via a device-dax
> - * character device.
> + * coherent and supports page pinning. This is for example used by DAX 
> devices
> + * that expose memory using a character device.
>   *
>   * MEMORY_DEVICE_PCI_P2PDMA:
>   * Device memory residing in a PCI BAR intended for use with Peer-to-Peer
> @@ -60,7 +59,7 @@ enum memory_type {
>       /* 0 is reserved to catch uninitialized type fields */
>       MEMORY_DEVICE_PRIVATE = 1,
>       MEMORY_DEVICE_FS_DAX,
> -     MEMORY_DEVICE_DEVDAX,
> +     MEMORY_DEVICE_GENERIC,
>       MEMORY_DEVICE_PCI_P2PDMA,
>  };
>  
> diff --git a/mm/memremap.c b/mm/memremap.c
> index 03e38b7a38f1..006dace60b1a 100644
> --- a/mm/memremap.c
> +++ b/mm/memremap.c
> @@ -216,7 +216,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
>                       return ERR_PTR(-EINVAL);
>               }
>               break;
> -     case MEMORY_DEVICE_DEVDAX:
> +     case MEMORY_DEVICE_GENERIC:
>               need_devmap_managed = false;
>               break;
>       case MEMORY_DEVICE_PCI_P2PDMA:
> 

No strong opinion (@Dan?), I do wonder if a separate type would make sense.

-- 
Thanks,

David / dhildenb