]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
drivers/base/devres: introduce devm_release_action()
authorDan Williams <dan.j.williams@intel.com>
Thu, 13 Jun 2019 22:56:18 +0000 (15:56 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 14 Jun 2019 03:34:56 +0000 (17:34 -1000)
commit2374b682255184d7ef75fcb507ce5af4995ead32
treecfd33b71a124a92ddf990a920bb10e10e8d0bc05
parenta58f2cef26e1ca44182c8b22f4f4395e702a5795
drivers/base/devres: introduce devm_release_action()

Patch series "mm/devm_memremap_pages: Fix page release race", v2.

Logan audited the devm_memremap_pages() shutdown path and noticed that
it was possible to proceed to arch_remove_memory() before all potential
page references have been reaped.

Introduce a new ->cleanup() callback to do the work of waiting for any
straggling page references and then perform the percpu_ref_exit() in
devm_memremap_pages_release() context.

For p2pdma this involves some deeper reworks to reference count
resources on a per-instance basis rather than a per pci-device basis.  A
modified genalloc api is introduced to convey a driver-private pointer
through gen_pool_{alloc,free}() interfaces.  Also, a
devm_memunmap_pages() api is introduced since p2pdma does not
auto-release resources on a setup failure.

The dax and pmem changes pass the nvdimm unit tests, and the p2pdma
changes should now pass testing with the pci_p2pdma_release() fix.
Jrme, how does this look for HMM?

This patch (of 6):

The devm_add_action() facility allows a resource allocation routine to
add custom devm semantics.  One such user is devm_memremap_pages().

There is now a need to manually trigger
devm_memremap_pages_release().  Introduce devm_release_action() so the
release action can be triggered via a new devm_memunmap_pages() api in a
follow-on change.

Link: http://lkml.kernel.org/r/155727336530.292046.2926860263201336366.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/base/devres.c
include/linux/device.h