linux-stable.git/kernel/memremap.c, branch master

memremap: move from kernel/ to mm/

2019-08-03T14:02:01+00:00

memremap.c implements MM functionality for ZONE_DEVICE, so it really
should be in the mm/ directory, not the kernel/ one.

Link: http://lkml.kernel.org/r/20190722094143.18387-1-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Anshuman Khandual 
Acked-by: Dan Williams 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/devm_memremap_pages: enable sub-section remap

2019-07-19T00:08:07+00:00

Teach devm_memremap_pages() about the new sub-section capabilities of
arch_{add,remove}_memory().  Effectively, just replace all usage of
align_start, align_end, and align_size with res->start, res->end, and
resource_size(res).  The existing sanity check will still make sure that
the two separate remap attempts do not collide within a sub-section (2MB
on x86).

Link: http://lkml.kernel.org/r/156092355542.979959.10060071713397030576.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams 
Tested-by: Aneesh Kumar K.V 	[ppc64]
Cc: Michal Hocko 
Cc: Toshi Kani 
Cc: Jérôme Glisse 
Cc: Logan Gunthorpe 
Cc: Oscar Salvador 
Cc: Pavel Tatashin 
Cc: David Hildenbrand 
Cc: Jane Chu 
Cc: Jeff Moyer 
Cc: Jonathan Corbet 
Cc: Mike Rapoport 
Cc: Vlastimil Babka 
Cc: Wei Yang 
Cc: Jason Gunthorpe 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memremap: provide an optional internal refcount in struct dev_pagemap

2019-07-02T17:32:44+00:00

Provide an internal refcounting logic if no ->ref field is provided
in the pagemap passed into devm_memremap_pages so that callers don't
have to reinvent it poorly.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Ira Weiny 
Reviewed-by: Dan Williams 
Tested-by: Dan Williams 
Signed-off-by: Jason Gunthorpe

memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag

2019-07-02T17:32:44+00:00

Add a flags field to struct dev_pagemap to replace the altmap_valid
boolean to be a little more extensible.  Also add a pgmap_altmap() helper
to find the optional altmap and clean up the code using the altmap using
it.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Ira Weiny 
Reviewed-by: Dan Williams 
Tested-by: Dan Williams 
Signed-off-by: Jason Gunthorpe

memremap: remove the data field in struct dev_pagemap

2019-07-02T17:32:44+00:00

struct dev_pagemap is always embedded into a containing structure, so
there is no need to an additional private data field.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Dan Williams 
Tested-by: Dan Williams 
Signed-off-by: Jason Gunthorpe

memremap: add a migrate_to_ram method to struct dev_pagemap_ops

2019-07-02T17:32:44+00:00

This replaces the hacky ->fault callback, which is currently directly
called from common code through a hmm specific data structure as an
exercise in layering violations.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Ralph Campbell 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Dan Williams 
Tested-by: Dan Williams 
Signed-off-by: Jason Gunthorpe

memremap: lift the devmap_enable manipulation into devm_memremap_pages

2019-07-02T17:32:44+00:00

Just check if there is a ->page_free operation set and take care of the
static key enable, as well as the put using device managed resources.
Also check that a ->page_free is provided for the pgmaps types that
require it, and check for a valid type as well while we are at it.

Note that this also fixes the fact that hmm never called
dev_pagemap_put_ops and thus would leave the slow path enabled forever,
even after a device driver unload or disable.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Ira Weiny 
Reviewed-by: Dan Williams 
Tested-by: Dan Williams 
Signed-off-by: Jason Gunthorpe

memremap: pass a struct dev_pagemap to ->kill and ->cleanup

2019-07-02T17:32:44+00:00

Passing the actual typed structure leads to more understandable code
vs just passing the ref member.

Reported-by: Logan Gunthorpe 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Logan Gunthorpe 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Dan Williams 
Tested-by: Dan Williams 
Signed-off-by: Jason Gunthorpe

memremap: move dev_pagemap callbacks into a separate structure

2019-07-02T17:32:44+00:00

The dev_pagemap is a growing too many callbacks.  Move them into a
separate ops structure so that they are not duplicated for multiple
instances, and an attacker can't easily overwrite them.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Logan Gunthorpe 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Dan Williams 
Tested-by: Dan Williams 
Signed-off-by: Jason Gunthorpe

memremap: validate the pagemap type passed to devm_memremap_pages

2019-07-02T17:32:44+00:00

Most pgmap types are only supported when certain config options are
enabled.  Check for a type that is valid for the current configuration
before setting up the pagemap.  For this the usage of the 0 type for
device dax gets replaced with an explicit MEMORY_DEVICE_DEVDAX type.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Ira Weiny 
Reviewed-by: Dan Williams 
Tested-by: Dan Williams 
Signed-off-by: Jason Gunthorpe