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From: Dan Williams <dan.j.williams@intel.com>
To: akpm@linux-foundation.org
Cc: "Jérôme Glisse" <jglisse@redhat.com>,
	"Logan Gunthorpe" <logang@deltatee.com>,
	"Christoph Hellwig" <hch@lst.de>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH v7 7/7] mm, hmm: Mark hmm_devmem_{add, add_resource} EXPORT_SYMBOL_GPL
Date: Fri, 12 Oct 2018 10:50:08 -0700	[thread overview]
Message-ID: <153936660850.1198040.13706829678231288085.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <153936657159.1198040.4489957977352276272.stgit@dwillia2-desk3.amr.corp.intel.com>

The routines hmm_devmem_add(), and hmm_devmem_add_resource() duplicated
devm_memremap_pages() and are now simple now wrappers around the core
facility to inject a dev_pagemap instance into the global pgmap_radix
and hook page-idle events. The devm_memremap_pages() interface is base
infrastructure for HMM. HMM has more and deeper ties into the kernel
memory management implementation than base ZONE_DEVICE which is itself a
EXPORT_SYMBOL_GPL facility.

Originally, the HMM page structure creation routines copied the
devm_memremap_pages() code and reused ZONE_DEVICE. A cleanup to unify
the implementations was discussed during the initial review:
http://lkml.iu.edu/hypermail/linux/kernel/1701.2/00812.html
Recent work to extend devm_memremap_pages() for the peer-to-peer-DMA
facility enabled this cleanup to move forward.

In addition to the integration with devm_memremap_pages() HMM depends on
other GPL-only symbols:

    mmu_notifier_unregister_no_release
    percpu_ref
    region_intersects
    __class_create

It goes further to consume / indirectly expose functionality that is not
exported to any other driver:

    alloc_pages_vma
    walk_page_range

HMM is derived from devm_memremap_pages(), and extends deep core-kernel
fundamentals. Similar to devm_memremap_pages(), mark its entry points
EXPORT_SYMBOL_GPL().

Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 mm/hmm.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/hmm.c b/mm/hmm.c
index 2e72cb4188ca..90d1383c7e24 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -1062,7 +1062,7 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops,
 		return result;
 	return devmem;
 }
-EXPORT_SYMBOL(hmm_devmem_add);
+EXPORT_SYMBOL_GPL(hmm_devmem_add);
 
 struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops,
 					   struct device *device,
@@ -1116,7 +1116,7 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops,
 		return result;
 	return devmem;
 }
-EXPORT_SYMBOL(hmm_devmem_add_resource);
+EXPORT_SYMBOL_GPL(hmm_devmem_add_resource);
 
 /*
  * A device driver that wants to handle multiple devices memory through a


  parent reply	other threads:[~2018-10-12 18:01 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-12 17:49 [PATCH v7 0/7] mm: Merge hmm into devm_memremap_pages, mark GPL-only Dan Williams
2018-10-12 17:49 ` [PATCH v7 1/7] mm, devm_memremap_pages: Mark devm_memremap_pages() EXPORT_SYMBOL_GPL Dan Williams
2018-10-17  8:17   ` Michal Hocko
2018-10-17 16:30     ` Dan Williams
2018-10-23 17:01       ` Michal Hocko
2018-10-12 17:49 ` [PATCH v7 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support Dan Williams
2018-10-12 17:49 ` [PATCH v7 3/7] mm, devm_memremap_pages: Fix shutdown handling Dan Williams
2018-10-12 17:49 ` [PATCH v7 4/7] mm, devm_memremap_pages: Add MEMORY_DEVICE_PRIVATE support Dan Williams
2018-10-12 17:49 ` [PATCH v7 5/7] mm, hmm: Use devm semantics for hmm_devmem_{add, remove} Dan Williams
2018-10-12 17:50 ` [PATCH v7 6/7] mm, hmm: Replace hmm_devmem_pages_create() with devm_memremap_pages() Dan Williams
2018-10-12 17:50 ` Dan Williams [this message]
2018-10-12 18:14 ` [PATCH v7 0/7] mm: Merge hmm into devm_memremap_pages, mark GPL-only Jerome Glisse

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