Changes since v4 [1]: * Rebase on v4.19-rc3 * Update changelogs and cover letter
[1]: https://lkml.org/lkml/2018/7/11/14
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Hi Andrew,
Back from vacation and this series is still top of mind. devm_memremap_pages() is a facility that can create struct page entries for any arbitrary range and give drivers the ability to subvert core aspects of page management. It, and anything derived from it (e.g. hmm, pcip2p, etc...), is an EXPORT_SYMBOL_GPL() interface.
I see that commit 31c5bda3a656 "mm: fix exports that inadvertently make put_page() EXPORT_SYMBOL_GPL" was merged ahead of this series to relieve some of the pressure from innocent consumers of put_page(), but now we need this series to address *producers* of device pages.
More details and justification in the changelogs. The 0day infrastructure has reported success across 182 configs and this survives the libnvdimm unit test suite. Aside from the controversial bits the diffstat is compelling at:
7 files changed, 138 insertions(+), 328 deletions(-).
Note that the series has some minor collisions with Alex's recent series to improve devm_memremap_pages() scalability [2]. So, whichever you take first the other will need a minor rebase.
[2]: https://www.lkml.org/lkml/2018/9/11/10
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Dan Williams (7): mm, devm_memremap_pages: Mark devm_memremap_pages() EXPORT_SYMBOL_GPL mm, devm_memremap_pages: Kill mapping "System RAM" support mm, devm_memremap_pages: Fix shutdown handling mm, devm_memremap_pages: Add MEMORY_DEVICE_PRIVATE support mm, hmm: Use devm semantics for hmm_devmem_{add,remove} mm, hmm: Replace hmm_devmem_pages_create() with devm_memremap_pages() mm, hmm: Mark hmm_devmem_{add,add_resource} EXPORT_SYMBOL_GPL
drivers/dax/pmem.c | 15 -- drivers/nvdimm/pmem.c | 18 +- include/linux/hmm.h | 4 include/linux/memremap.h | 7 + kernel/memremap.c | 98 ++++++++---- mm/hmm.c | 303 +++++-------------------------------- tools/testing/nvdimm/test/iomap.c | 21 ++- 7 files changed, 138 insertions(+), 328 deletions(-)