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

[Ira Weiny <ira.weiny@xxxxxxxxx>]

On Mon, Aug 31, 2020 at 12:19:07PM +0200, Roger Pau Monné wrote:
> On Thu, Aug 20, 2020 at 01:37:41PM +0200, Roger Pau Monné wrote:
> > On Tue, Aug 11, 2020 at 11:07:36PM +0200, David Hildenbrand wrote:
> > > 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>

Dan is out on leave so I'll chime in.

I can't really justify keeping this as DEVDAX if there is another user who
needs the same type of mapping.

Sorry for the delay.

Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>

> > > > ---
> > > > 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.
> > 
> > Gentle ping.
> 
> Sorry to ping again, but I would rather get this out of my queue if
> possible, seeing as the other patch is OK to go in but depends on this
> one going in first.
> 
> Thanks, Roger.