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* docs: early-userspace: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-07-156-10/+38
| | | | | | | | | | | | | | | The two files there describes a Kernel API feature, used to support early userspace stuff. Prepare for moving them to the kernel API book by converting to ReST format. The conversion itself was quite trivial: just add/mark a few titles as such, add a literal block markup, add a table markup and a few blank lines, in order to make Sphinx to properly parse it. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* docs: pti_intel_mid.txt: convert it to pti_intel_mid.rstMauro Carvalho Chehab2019-07-152-99/+106
| | | | | | | | | | | | Convert this small file to ReST format and rename it. Most of the conversion were related to adjusting whitespaces in order for each section to be properly parsed. While this is not part of any book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* docs: console.txt: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-07-153-31/+38
| | | | | | | | | | | | Convert this small file to ReST in preparation for adding it to the driver-api book. While this is not part of the driver-api book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
* docs: cma/debugfs.txt: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-07-151-1/+7
| | | | | | | | | | | | | | | | The debugfs interface for CMA should be there together with other mm-related documents. Convert this small file to ReST and move it to its rightful place. The conversion is actually quite simple: just add a title for the document. In order to make it to look better for the audience, also mark the "echo" command as a literal block. While this is not part of any book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* docs: m68k: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-07-153-147/+191
| | | | | | | | | | | | | | Convert the m68k kernel-options.txt file to ReST. The conversion is trivial, as the document is already on a format close enough to ReST. Just some small adjustments were needed in order to make it both good for being parsed while keeping it on a good txt shape. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* docs: lp855x-driver.txt: convert to ReST and move to kernel-apiMauro Carvalho Chehab2019-07-153-67/+84
| | | | | | | | | | | | | | | This small file seems to be an attempt to start documenting backlight drivers. It contains descriptions of the controls for the driver with could sound as an somewhat user-faced description, but it's main focus is to describe, instead, the data that should be passed via platform data and some driver-specific stuff. While this is not part of the driver-api book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* docs: lcd-panel-cgram.txt: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-07-152-3/+8
| | | | | | | | | | | This small text file describes the usage of parallel port LCD displays from userspace PoV. So, a good candidate for the admin guide. While this is not part of the admin-guide book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* docs: connector: convert to ReST and rename to connector.rstMauro Carvalho Chehab2019-07-154-88/+109
| | | | | | | | | | | | | | | | As it has some function definitions, move them to connector.h. The remaining conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* docs: locking: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-07-1520-387/+511
| | | | | | | | | | | | | | | | | | | | | | Convert the locking documents to ReST and add them to the kernel development book where it belongs. Most of the stuff here is just to make Sphinx to properly parse the text file, as they're already in good shape, not requiring massive changes in order to be parsed. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Federico Vaga <federico.vaga@vaga.pv.it>
* Merge tag 'for-linus-hmm' of ↵Linus Torvalds2019-07-1436-1327/+620
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma Pull HMM updates from Jason Gunthorpe: "Improvements and bug fixes for the hmm interface in the kernel: - Improve clarity, locking and APIs related to the 'hmm mirror' feature merged last cycle. In linux-next we now see AMDGPU and nouveau to be using this API. - Remove old or transitional hmm APIs. These are hold overs from the past with no users, or APIs that existed only to manage cross tree conflicts. There are still a few more of these cleanups that didn't make the merge window cut off. - Improve some core mm APIs: - export alloc_pages_vma() for driver use - refactor into devm_request_free_mem_region() to manage DEVICE_PRIVATE resource reservations - refactor duplicative driver code into the core dev_pagemap struct - Remove hmm wrappers of improved core mm APIs, instead have drivers use the simplified API directly - Remove DEVICE_PUBLIC - Simplify the kconfig flow for the hmm users and core code" * tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits) mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR mm: remove the HMM config option mm: sort out the DEVICE_PRIVATE Kconfig mess mm: simplify ZONE_DEVICE page private data mm: remove hmm_devmem_add mm: remove hmm_vma_alloc_locked_page nouveau: use devm_memremap_pages directly nouveau: use alloc_page_vma directly PCI/P2PDMA: use the dev_pagemap internal refcount device-dax: use the dev_pagemap internal refcount memremap: provide an optional internal refcount in struct dev_pagemap memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag memremap: remove the data field in struct dev_pagemap memremap: add a migrate_to_ram method to struct dev_pagemap_ops memremap: lift the devmap_enable manipulation into devm_memremap_pages memremap: pass a struct dev_pagemap to ->kill and ->cleanup memremap: move dev_pagemap callbacks into a separate structure memremap: validate the pagemap type passed to devm_memremap_pages mm: factor out a devm_request_free_mem_region helper mm: export alloc_pages_vma ...
| * Merge branch 'hmm-devmem-cleanup.4' into rdma.git hmmJason Gunthorpe2019-07-0233-1013/+370
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Christoph Hellwig says: ==================== Below is a series that cleans up the dev_pagemap interface so that it is more easily usable, which removes the need to wrap it in hmm and thus allowing to kill a lot of code Changes since v3: - pull in "mm/swap: Fix release_pages() when releasing devmap pages" and rebase the other patches on top of that - fold the hmm_devmem_add_resource into the DEVICE_PUBLIC memory removal patch - remove _vm_normal_page as it isn't needed without DEVICE_PUBLIC memory - pick up various ACKs Changes since v2: - fix nvdimm kunit build - add a new memory type for device dax - fix a few issues in intermediate patches that didn't show up in the end result - incorporate feedback from Michal Hocko, including killing of the DEVICE_PUBLIC memory type entirely Changes since v1: - rebase - also switch p2pdma to the internal refcount - add type checking for pgmap->type - rename the migrate method to migrate_to_ram - cleanup the altmap_valid flag - various tidbits from the reviews ==================== Conflicts resolved by: - Keeping Ira's version of the code in swap.c - Using the delete for the section in hmm.rst - Using the delete for the devmap code in hmm.c and .h * branch 'hmm-devmem-cleanup.4': (24 commits) mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR mm: remove the HMM config option mm: sort out the DEVICE_PRIVATE Kconfig mess mm: simplify ZONE_DEVICE page private data mm: remove hmm_devmem_add mm: remove hmm_vma_alloc_locked_page nouveau: use devm_memremap_pages directly nouveau: use alloc_page_vma directly PCI/P2PDMA: use the dev_pagemap internal refcount device-dax: use the dev_pagemap internal refcount memremap: provide an optional internal refcount in struct dev_pagemap memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag memremap: remove the data field in struct dev_pagemap memremap: add a migrate_to_ram method to struct dev_pagemap_ops memremap: lift the devmap_enable manipulation into devm_memremap_pages memremap: pass a struct dev_pagemap to ->kill and ->cleanup memremap: move dev_pagemap callbacks into a separate structure memremap: validate the pagemap type passed to devm_memremap_pages mm: factor out a devm_request_free_mem_region helper mm: export alloc_pages_vma ... Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: don't select MIGRATE_VMA_HELPER from HMM_MIRRORChristoph Hellwig2019-07-022-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The migrate_vma helper is only used by noveau to migrate device private pages around. Other HMM_MIRROR users like amdgpu or infiniband don't need it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: remove the HMM config optionChristoph Hellwig2019-07-026-33/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All the mm/hmm.c code is better keyed off HMM_MIRROR. Also let nouveau depend on it instead of the mix of a dummy dependency symbol plus the actually selected one. Drop various odd dependencies, as the code is pretty portable. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: sort out the DEVICE_PRIVATE Kconfig messChristoph Hellwig2019-07-022-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ZONE_DEVICE support doesn't depend on anything HMM related, just on various bits of arch support as indicated by the architecture. Also don't select the option from nouveau as it isn't present in many setups, and depend on it instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: simplify ZONE_DEVICE page private dataChristoph Hellwig2019-07-024-48/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the clumsy hmm_devmem_page_{get,set}_drvdata helpers, and instead just access the page directly. Also make the page data a void pointer, and thus much easier to use. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: remove hmm_devmem_addChristoph Hellwig2019-07-023-265/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There isn't really much value add in the hmm_devmem_add wrapper and more, as using devm_memremap_pages directly now is just as simple. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: remove hmm_vma_alloc_locked_pageChristoph Hellwig2019-07-022-17/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only user of it has just been removed, and there wasn't really any need to wrap a basic memory allocator to start with. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * nouveau: use devm_memremap_pages directlyChristoph Hellwig2019-07-021-44/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | Just use devm_memremap_pages instead of hmm_devmem_add pages to allow killing that wrapper which doesn't provide a whole lot of benefits. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * nouveau: use alloc_page_vma directlyChristoph Hellwig2019-07-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hmm_vma_alloc_locked_page is scheduled to go away, use the proper mm function directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * PCI/P2PDMA: use the dev_pagemap internal refcountChristoph Hellwig2019-07-021-53/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The functionality is identical to the one currently open coded in p2pdma.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Tested-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * device-dax: use the dev_pagemap internal refcountChristoph Hellwig2019-07-022-47/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The functionality is identical to the one currently open coded in device-dax. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * memremap: provide an optional internal refcount in struct dev_pagemapChristoph Hellwig2019-07-023-25/+101
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flagChristoph Hellwig2019-07-029-43/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * memremap: remove the data field in struct dev_pagemapChristoph Hellwig2019-07-024-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * memremap: add a migrate_to_ram method to struct dev_pagemap_opsChristoph Hellwig2019-07-026-67/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <hch@lst.de> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * memremap: lift the devmap_enable manipulation into devm_memremap_pagesChristoph Hellwig2019-07-024-53/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * memremap: pass a struct dev_pagemap to ->kill and ->cleanupChristoph Hellwig2019-07-027-32/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Passing the actual typed structure leads to more understandable code vs just passing the ref member. Reported-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * memremap: move dev_pagemap callbacks into a separate structureChristoph Hellwig2019-07-028-46/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <hch@lst.de> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * memremap: validate the pagemap type passed to devm_memremap_pagesChristoph Hellwig2019-07-023-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: factor out a devm_request_free_mem_region helperChristoph Hellwig2019-07-023-29/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Keep the physical address allocation that hmm_add_device does with the rest of the resource code, and allow future reuse of it without the hmm wrapper. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: export alloc_pages_vmaChristoph Hellwig2019-07-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nouveau is currently using this through an odd hmm wrapper, and I plan to switch it to the real thing later in this series. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: don't clear ->mapping in hmm_devmem_freeChristoph Hellwig2019-07-021-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ->mapping isn't even used by HMM users, and the field at the same offset in the zone_device part of the union is declared as pad. (Which btw is rather confusing, as DAX uses ->pgmap and ->mapping from two different sides of the union, but DAX doesn't use hmm_devmem_free). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: remove MEMORY_DEVICE_PUBLIC supportChristoph Hellwig2019-07-0214-186/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code hasn't been used since it was added to the tree, and doesn't appear to actually be usable. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: remove the struct hmm_device infrastructureChristoph Hellwig2019-07-022-100/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This code is a trivial wrapper around device model helpers, which should have been integrated into the driver device model usage from the start. Assuming it actually had users, which it never had since the code was added more than 1 1/2 years ago. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| | * mm: remove the unused ARCH_HAS_HMM_DEVICE Kconfig optionChristoph Hellwig2019-07-021-10/+0
| | | | | | | | | | | | | | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| * | Merge tag 'v5.2-rc7' into rdma.git hmmJason Gunthorpe2019-07-029579-62626/+19751
| |\| | | | | | | | | | Required for dependencies in the next patches.
| * | mm/swap: fix release_pages() when releasing devmap pagesIra Weiny2019-07-021-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | release_pages() is an optimized version of a loop around put_page(). Unfortunately for devmap pages the logic is not entirely correct in release_pages(). This is because device pages can be more than type MEMORY_DEVICE_PUBLIC. There are in fact 4 types, private, public, FS DAX, and PCI P2PDMA. Some of these have specific needs to "put" the page while others do not. This logic to handle any special needs is contained in put_devmap_managed_page(). Therefore all devmap pages should be processed by this function where we can contain the correct logic for a page put. Handle all device type pages within release_pages() by calling put_devmap_managed_page() on all devmap pages. If put_devmap_managed_page() returns true the page has been put and we continue with the next page. A false return of put_devmap_managed_page() means the page did not require special processing and should fall to "normal" processing. This was found via code inspection while determining if release_pages() and the new put_user_pages() could be interchangeable.[1] [1] https://lkml.kernel.org/r/20190523172852.GA27175@iweiny-DESK2.sc.intel.com Link: https://lkml.kernel.org/r/20190605214922.17684-1-ira.weiny@intel.com Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
| * | mm/hmm: Fix error flows in hmm_invalidate_range_startJason Gunthorpe2019-06-272-30/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the trylock on the hmm->mirrors_sem fails the function will return without decrementing the notifiers that were previously incremented. Since the caller will not call invalidate_range_end() on EAGAIN this will result in notifiers becoming permanently incremented and deadlock. If the sync_cpu_device_pagetables() required blocking the function will not return EAGAIN even though the device continues to touch the pages. This is a violation of the mmu notifier contract. Switch, and rename, the ranges_lock to a spin lock so we can reliably obtain it without blocking during error unwind. The error unwind is necessary since the notifiers count must be held incremented across the call to sync_cpu_device_pagetables() as we cannot allow the range to become marked valid by a parallel invalidate_start/end() pair while doing sync_cpu_device_pagetables(). Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Remove confusing comment and logic from hmm_releaseJason Gunthorpe2019-06-241-19/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hmm_release() is called exactly once per hmm. ops->release() cannot accidentally trigger any action that would recurse back onto hmm->mirrors_sem. This fixes a use after-free race of the form: CPU0 CPU1 hmm_release() up_write(&hmm->mirrors_sem); hmm_mirror_unregister(mirror) down_write(&hmm->mirrors_sem); up_write(&hmm->mirrors_sem); kfree(mirror) mirror->ops->release(mirror) The only user we have today for ops->release is an empty function, so this is unambiguously safe. As a consequence of plugging this race drivers are not allowed to register/unregister mirrors from within a release op. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Poison hmm_range during unregisterJason Gunthorpe2019-06-241-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trying to misuse a range outside its lifetime is a kernel bug. Use poison bytes to help detect this condition. Double unregister will reliably crash. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Remove racy protection against double-unregistrationJason Gunthorpe2019-06-241-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No other register/unregister kernel API attempts to provide this kind of protection as it is inherently racy, so just drop it. Callers should provide their own protection, and it appears nouveau already does. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Use lockdep instead of commentsJason Gunthorpe2019-06-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So we can check locking at runtime. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Acked-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Hold on to the mmget for the lifetime of the rangeJason Gunthorpe2019-06-182-47/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Range functions like hmm_range_snapshot() and hmm_range_fault() call find_vma, which requires hodling the mmget() and the mmap_sem for the mm. Make this simpler for the callers by holding the mmget() inside the range for the lifetime of the range. Other functions that accept a range should only be called if the range is registered. This has the side effect of directly preventing hmm_release() from happening while a range is registered. That means range->dead cannot be false during the lifetime of the range, so remove dead and hmm_mirror_mm_is_alive() entirely. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Do not use list*_rcu() for hmm->rangesJason Gunthorpe2019-06-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This list is always read and written while holding hmm->lock so there is no need for the confusing _rcu annotations. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <iweiny@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Remove duplicate condition test before wait_event_timeoutJason Gunthorpe2019-06-181-11/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The wait_event_timeout macro already tests the condition as its first action, so there is no reason to open code another version of this, all that does is skip the might_sleep() debugging in common cases, which is not helpful. Further, based on prior patches, we can now simplify the required condition test: - If range is valid memory then so is range->hmm - If hmm_release() has run then range->valid is set to false at the same time as dead, so no reason to check both. - A valid hmm has a valid hmm->mm. Allowing the return value of wait_event_timeout() (along with its internal barriers) to compute the result of the function. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Simplify hmm_get_or_create and make it reliableJason Gunthorpe2019-06-181-47/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As coded this function can false-fail in various racy situations. Make it reliable and simpler by running under the write side of the mmap_sem and avoiding the false-failing compare/exchange pattern. Due to the mmap_sem this no longer has to avoid racing with a 2nd parallel hmm_get_or_create(). Unfortunately this still has to use the page_table_lock as the non-sleeping lock protecting mm->hmm, since the contexts where we free the hmm are incompatible with mmap_sem. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Hold a mmgrab from hmm to mmJason Gunthorpe2019-06-103-22/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So long as a struct hmm pointer exists, so should the struct mm it is linked too. Hold the mmgrab() as soon as a hmm is created, and mmdrop() it once the hmm refcount goes to zero. Since mmdrop() (ie a 0 kref on struct mm) is now impossible with a !NULL mm->hmm delete the hmm_hmm_destroy(). Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Use hmm_mirror not mm as an argument for hmm_range_registerJason Gunthorpe2019-06-103-13/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ralph observes that hmm_range_register() can only be called by a driver while a mirror is registered. Make this clear in the API by passing in the mirror structure as a parameter. This also simplifies understanding the lifetime model for struct hmm, as the hmm pointer must be valid as part of a registered mirror so all we need in hmm_register_range() is a simple kref_get. Suggested-by: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: fix use after free with struct hmm in the mmu notifiersJason Gunthorpe2019-06-072-6/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mmu_notifier_unregister_no_release() is not a fence and the mmu_notifier system will continue to reference hmm->mn until the srcu grace period expires. Resulting in use after free races like this: CPU0 CPU1 __mmu_notifier_invalidate_range_start() srcu_read_lock hlist_for_each () // mn == hmm->mn hmm_mirror_unregister() hmm_put() hmm_free() mmu_notifier_unregister_no_release() hlist_del_init_rcu(hmm-mn->list) mn->ops->invalidate_range_start(mn, range); mm_get_hmm() mm->hmm = NULL; kfree(hmm) mutex_lock(&hmm->lock); Use SRCU to kfree the hmm memory so that the notifiers can rely on hmm existing. Get the now-safe hmm struct through container_of and directly check kref_get_unless_zero to lock it against free. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
| * | mm/hmm: Only set FAULT_FLAG_ALLOW_RETRY for non-blockingKuehling, Felix2019-06-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't set this flag by default in hmm_vma_do_fault. It is set conditionally just a few lines below. Setting it unconditionally can lead to handle_mm_fault doing a non-blocking fault, returning -EBUSY and unlocking mmap_sem unexpectedly. Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-13 14:24:54 +0000