From eddb1c228f7951d399240a0cc57455dccc7f8777 Mon Sep 17 00:00:00 2001 From: John Hubbard Date: Thu, 30 Jan 2020 22:12:54 -0800 Subject: mm/gup: introduce pin_user_pages*() and FOLL_PIN MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Introduce pin_user_pages*() variations of get_user_pages*() calls, and also pin_longterm_pages*() variations. For now, these are placeholder calls, until the various call sites are converted to use the correct get_user_pages*() or pin_user_pages*() API. These variants will eventually all set FOLL_PIN, which is also introduced, and thoroughly documented. pin_user_pages() pin_user_pages_remote() pin_user_pages_fast() All pages that are pinned via the above calls, must be unpinned via put_user_page(). The underlying rules are: * FOLL_PIN is a gup-internal flag, so the call sites should not directly set it. That behavior is enforced with assertions. * Call sites that want to indicate that they are going to do DirectIO ("DIO") or something with similar characteristics, should call a get_user_pages()-like wrapper call that sets FOLL_PIN. These wrappers will: * Start with "pin_user_pages" instead of "get_user_pages". That makes it easy to find and audit the call sites. * Set FOLL_PIN * For pages that are received via FOLL_PIN, those pages must be returned via put_user_page(). Thanks to Jan Kara and Vlastimil Babka for explaining the 4 cases in this documentation. (I've reworded it and expanded upon it.) Link: http://lkml.kernel.org/r/20200107224558.2362728-12-jhubbard@nvidia.com Signed-off-by: John Hubbard Reviewed-by: Jan Kara Reviewed-by: Mike Rapoport [Documentation] Reviewed-by: Jérôme Glisse Cc: Jonathan Corbet Cc: Ira Weiny Cc: Alex Williamson Cc: Aneesh Kumar K.V Cc: Björn Töpel Cc: Christoph Hellwig Cc: Daniel Vetter Cc: Dan Williams Cc: Hans Verkuil Cc: Jason Gunthorpe Cc: Jason Gunthorpe Cc: Jens Axboe Cc: Kirill A. Shutemov Cc: Leon Romanovsky Cc: Mauro Carvalho Chehab Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/core-api/index.rst | 1 + Documentation/core-api/pin_user_pages.rst | 232 ++++++++++++++++++++++++++++++ 2 files changed, 233 insertions(+) create mode 100644 Documentation/core-api/pin_user_pages.rst (limited to 'Documentation/core-api') diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst index bc0c727d7fd8..a501dc1c90d0 100644 --- a/Documentation/core-api/index.rst +++ b/Documentation/core-api/index.rst @@ -31,6 +31,7 @@ Core utilities generic-radix-tree memory-allocation mm-api + pin_user_pages gfp_mask-from-fs-io timekeeping boot-time-mm diff --git a/Documentation/core-api/pin_user_pages.rst b/Documentation/core-api/pin_user_pages.rst new file mode 100644 index 000000000000..71849830cd48 --- /dev/null +++ b/Documentation/core-api/pin_user_pages.rst @@ -0,0 +1,232 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================================================== +pin_user_pages() and related calls +==================================================== + +.. contents:: :local: + +Overview +======== + +This document describes the following functions:: + + pin_user_pages() + pin_user_pages_fast() + pin_user_pages_remote() + +Basic description of FOLL_PIN +============================= + +FOLL_PIN and FOLL_LONGTERM are flags that can be passed to the get_user_pages*() +("gup") family of functions. FOLL_PIN has significant interactions and +interdependencies with FOLL_LONGTERM, so both are covered here. + +FOLL_PIN is internal to gup, meaning that it should not appear at the gup call +sites. This allows the associated wrapper functions (pin_user_pages*() and +others) to set the correct combination of these flags, and to check for problems +as well. + +FOLL_LONGTERM, on the other hand, *is* allowed to be set at the gup call sites. +This is in order to avoid creating a large number of wrapper functions to cover +all combinations of get*(), pin*(), FOLL_LONGTERM, and more. Also, the +pin_user_pages*() APIs are clearly distinct from the get_user_pages*() APIs, so +that's a natural dividing line, and a good point to make separate wrapper calls. +In other words, use pin_user_pages*() for DMA-pinned pages, and +get_user_pages*() for other cases. There are four cases described later on in +this document, to further clarify that concept. + +FOLL_PIN and FOLL_GET are mutually exclusive for a given gup call. However, +multiple threads and call sites are free to pin the same struct pages, via both +FOLL_PIN and FOLL_GET. It's just the call site that needs to choose one or the +other, not the struct page(s). + +The FOLL_PIN implementation is nearly the same as FOLL_GET, except that FOLL_PIN +uses a different reference counting technique. + +FOLL_PIN is a prerequisite to FOLL_LONGTERM. Another way of saying that is, +FOLL_LONGTERM is a specific case, more restrictive case of FOLL_PIN. + +Which flags are set by each wrapper +=================================== + +For these pin_user_pages*() functions, FOLL_PIN is OR'd in with whatever gup +flags the caller provides. The caller is required to pass in a non-null struct +pages* array, and the function then pin pages by incrementing each by a special +value. For now, that value is +1, just like get_user_pages*().:: + + Function + -------- + pin_user_pages FOLL_PIN is always set internally by this function. + pin_user_pages_fast FOLL_PIN is always set internally by this function. + pin_user_pages_remote FOLL_PIN is always set internally by this function. + +For these get_user_pages*() functions, FOLL_GET might not even be specified. +Behavior is a little more complex than above. If FOLL_GET was *not* specified, +but the caller passed in a non-null struct pages* array, then the function +sets FOLL_GET for you, and proceeds to pin pages by incrementing the refcount +of each page by +1.:: + + Function + -------- + get_user_pages FOLL_GET is sometimes set internally by this function. + get_user_pages_fast FOLL_GET is sometimes set internally by this function. + get_user_pages_remote FOLL_GET is sometimes set internally by this function. + +Tracking dma-pinned pages +========================= + +Some of the key design constraints, and solutions, for tracking dma-pinned +pages: + +* An actual reference count, per struct page, is required. This is because + multiple processes may pin and unpin a page. + +* False positives (reporting that a page is dma-pinned, when in fact it is not) + are acceptable, but false negatives are not. + +* struct page may not be increased in size for this, and all fields are already + used. + +* Given the above, we can overload the page->_refcount field by using, sort of, + the upper bits in that field for a dma-pinned count. "Sort of", means that, + rather than dividing page->_refcount into bit fields, we simple add a medium- + large value (GUP_PIN_COUNTING_BIAS, initially chosen to be 1024: 10 bits) to + page->_refcount. This provides fuzzy behavior: if a page has get_page() called + on it 1024 times, then it will appear to have a single dma-pinned count. + And again, that's acceptable. + +This also leads to limitations: there are only 31-10==21 bits available for a +counter that increments 10 bits at a time. + +TODO: for 1GB and larger huge pages, this is cutting it close. That's because +when pin_user_pages() follows such pages, it increments the head page by "1" +(where "1" used to mean "+1" for get_user_pages(), but now means "+1024" for +pin_user_pages()) for each tail page. So if you have a 1GB huge page: + +* There are 256K (18 bits) worth of 4 KB tail pages. +* There are 21 bits available to count up via GUP_PIN_COUNTING_BIAS (that is, + 10 bits at a time) +* There are 21 - 18 == 3 bits available to count. Except that there aren't, + because you need to allow for a few normal get_page() calls on the head page, + as well. Fortunately, the approach of using addition, rather than "hard" + bitfields, within page->_refcount, allows for sharing these bits gracefully. + But we're still looking at about 8 references. + +This, however, is a missing feature more than anything else, because it's easily +solved by addressing an obvious inefficiency in the original get_user_pages() +approach of retrieving pages: stop treating all the pages as if they were +PAGE_SIZE. Retrieve huge pages as huge pages. The callers need to be aware of +this, so some work is required. Once that's in place, this limitation mostly +disappears from view, because there will be ample refcounting range available. + +* Callers must specifically request "dma-pinned tracking of pages". In other + words, just calling get_user_pages() will not suffice; a new set of functions, + pin_user_page() and related, must be used. + +FOLL_PIN, FOLL_GET, FOLL_LONGTERM: when to use which flags +========================================================== + +Thanks to Jan Kara, Vlastimil Babka and several other -mm people, for describing +these categories: + +CASE 1: Direct IO (DIO) +----------------------- +There are GUP references to pages that are serving +as DIO buffers. These buffers are needed for a relatively short time (so they +are not "long term"). No special synchronization with page_mkclean() or +munmap() is provided. Therefore, flags to set at the call site are: :: + + FOLL_PIN + +...but rather than setting FOLL_PIN directly, call sites should use one of +the pin_user_pages*() routines that set FOLL_PIN. + +CASE 2: RDMA +------------ +There are GUP references to pages that are serving as DMA +buffers. These buffers are needed for a long time ("long term"). No special +synchronization with page_mkclean() or munmap() is provided. Therefore, flags +to set at the call site are: :: + + FOLL_PIN | FOLL_LONGTERM + +NOTE: Some pages, such as DAX pages, cannot be pinned with longterm pins. That's +because DAX pages do not have a separate page cache, and so "pinning" implies +locking down file system blocks, which is not (yet) supported in that way. + +CASE 3: Hardware with page faulting support +------------------------------------------- +Here, a well-written driver doesn't normally need to pin pages at all. However, +if the driver does choose to do so, it can register MMU notifiers for the range, +and will be called back upon invalidation. Either way (avoiding page pinning, or +using MMU notifiers to unpin upon request), there is proper synchronization with +both filesystem and mm (page_mkclean(), munmap(), etc). + +Therefore, neither flag needs to be set. + +In this case, ideally, neither get_user_pages() nor pin_user_pages() should be +called. Instead, the software should be written so that it does not pin pages. +This allows mm and filesystems to operate more efficiently and reliably. + +CASE 4: Pinning for struct page manipulation only +------------------------------------------------- +Here, normal GUP calls are sufficient, so neither flag needs to be set. + +page_dma_pinned(): the whole point of pinning +============================================= + +The whole point of marking pages as "DMA-pinned" or "gup-pinned" is to be able +to query, "is this page DMA-pinned?" That allows code such as page_mkclean() +(and file system writeback code in general) to make informed decisions about +what to do when a page cannot be unmapped due to such pins. + +What to do in those cases is the subject of a years-long series of discussions +and debates (see the References at the end of this document). It's a TODO item +here: fill in the details once that's worked out. Meanwhile, it's safe to say +that having this available: :: + + static inline bool page_dma_pinned(struct page *page) + +...is a prerequisite to solving the long-running gup+DMA problem. + +Another way of thinking about FOLL_GET, FOLL_PIN, and FOLL_LONGTERM +=================================================================== + +Another way of thinking about these flags is as a progression of restrictions: +FOLL_GET is for struct page manipulation, without affecting the data that the +struct page refers to. FOLL_PIN is a *replacement* for FOLL_GET, and is for +short term pins on pages whose data *will* get accessed. As such, FOLL_PIN is +a "more severe" form of pinning. And finally, FOLL_LONGTERM is an even more +restrictive case that has FOLL_PIN as a prerequisite: this is for pages that +will be pinned longterm, and whose data will be accessed. + +Unit testing +============ +This file:: + + tools/testing/selftests/vm/gup_benchmark.c + +has the following new calls to exercise the new pin*() wrapper functions: + +* PIN_FAST_BENCHMARK (./gup_benchmark -a) +* PIN_BENCHMARK (./gup_benchmark -b) + +You can monitor how many total dma-pinned pages have been acquired and released +since the system was booted, via two new /proc/vmstat entries: :: + + /proc/vmstat/nr_foll_pin_requested + /proc/vmstat/nr_foll_pin_requested + +Those are both going to show zero, unless CONFIG_DEBUG_VM is set. This is +because there is a noticeable performance drop in put_user_page(), when they +are activated. + +References +========== + +* `Some slow progress on get_user_pages() (Apr 2, 2019) `_ +* `DMA and get_user_pages() (LPC: Dec 12, 2018) `_ +* `The trouble with get_user_pages() (Apr 30, 2018) `_ + +John Hubbard, October, 2019 -- cgit From f1f6a7dd9b53aafd81b696b9017036e7b08e57ea Mon Sep 17 00:00:00 2001 From: John Hubbard Date: Thu, 30 Jan 2020 22:13:35 -0800 Subject: mm, tree-wide: rename put_user_page*() to unpin_user_page*() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In order to provide a clearer, more symmetric API for pinning and unpinning DMA pages. This way, pin_user_pages*() calls match up with unpin_user_pages*() calls, and the API is a lot closer to being self-explanatory. Link: http://lkml.kernel.org/r/20200107224558.2362728-23-jhubbard@nvidia.com Signed-off-by: John Hubbard Reviewed-by: Jan Kara Cc: Alex Williamson Cc: Aneesh Kumar K.V Cc: Björn Töpel Cc: Christoph Hellwig Cc: Daniel Vetter Cc: Dan Williams Cc: Hans Verkuil Cc: Ira Weiny Cc: Jason Gunthorpe Cc: Jason Gunthorpe Cc: Jens Axboe Cc: Jerome Glisse Cc: Jonathan Corbet Cc: Kirill A. Shutemov Cc: Leon Romanovsky Cc: Mauro Carvalho Chehab Cc: Mike Rapoport Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/core-api/pin_user_pages.rst | 2 +- arch/powerpc/mm/book3s64/iommu_api.c | 4 ++-- drivers/gpu/drm/via/via_dmablit.c | 4 ++-- drivers/infiniband/core/umem.c | 2 +- drivers/infiniband/hw/hfi1/user_pages.c | 2 +- drivers/infiniband/hw/mthca/mthca_memfree.c | 6 +++--- drivers/infiniband/hw/qib/qib_user_pages.c | 2 +- drivers/infiniband/hw/qib/qib_user_sdma.c | 6 +++--- drivers/infiniband/hw/usnic/usnic_uiom.c | 2 +- drivers/infiniband/sw/siw/siw_mem.c | 2 +- drivers/media/v4l2-core/videobuf-dma-sg.c | 4 ++-- drivers/platform/goldfish/goldfish_pipe.c | 4 ++-- drivers/vfio/vfio_iommu_type1.c | 2 +- fs/io_uring.c | 4 ++-- include/linux/mm.h | 26 +++++++++++------------ mm/gup.c | 32 ++++++++++++++--------------- mm/process_vm_access.c | 4 ++-- net/xdp/xdp_umem.c | 2 +- 18 files changed, 55 insertions(+), 55 deletions(-) (limited to 'Documentation/core-api') diff --git a/Documentation/core-api/pin_user_pages.rst b/Documentation/core-api/pin_user_pages.rst index 71849830cd48..1d490155ecd7 100644 --- a/Documentation/core-api/pin_user_pages.rst +++ b/Documentation/core-api/pin_user_pages.rst @@ -219,7 +219,7 @@ since the system was booted, via two new /proc/vmstat entries: :: /proc/vmstat/nr_foll_pin_requested Those are both going to show zero, unless CONFIG_DEBUG_VM is set. This is -because there is a noticeable performance drop in put_user_page(), when they +because there is a noticeable performance drop in unpin_user_page(), when they are activated. References diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c index a86547822034..eba73ebd8ae5 100644 --- a/arch/powerpc/mm/book3s64/iommu_api.c +++ b/arch/powerpc/mm/book3s64/iommu_api.c @@ -168,7 +168,7 @@ good_exit: free_exit: /* free the references taken */ - put_user_pages(mem->hpages, pinned); + unpin_user_pages(mem->hpages, pinned); vfree(mem->hpas); kfree(mem); @@ -214,7 +214,7 @@ static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem) if (mem->hpas[i] & MM_IOMMU_TABLE_GROUP_PAGE_DIRTY) SetPageDirty(page); - put_user_page(page); + unpin_user_page(page); mem->hpas[i] = 0; } diff --git a/drivers/gpu/drm/via/via_dmablit.c b/drivers/gpu/drm/via/via_dmablit.c index 37c5e572993a..719d036c9384 100644 --- a/drivers/gpu/drm/via/via_dmablit.c +++ b/drivers/gpu/drm/via/via_dmablit.c @@ -188,8 +188,8 @@ via_free_sg_info(struct pci_dev *pdev, drm_via_sg_info_t *vsg) kfree(vsg->desc_pages); /* fall through */ case dr_via_pages_locked: - put_user_pages_dirty_lock(vsg->pages, vsg->num_pages, - (vsg->direction == DMA_FROM_DEVICE)); + unpin_user_pages_dirty_lock(vsg->pages, vsg->num_pages, + (vsg->direction == DMA_FROM_DEVICE)); /* fall through */ case dr_via_pages_alloc: vfree(vsg->pages); diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index aae5bfed7f3b..c3769a5f096d 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -54,7 +54,7 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d for_each_sg_page(umem->sg_head.sgl, &sg_iter, umem->sg_nents, 0) { page = sg_page_iter_page(&sg_iter); - put_user_pages_dirty_lock(&page, 1, umem->writable && dirty); + unpin_user_pages_dirty_lock(&page, 1, umem->writable && dirty); } sg_free_table(&umem->sg_head); diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c index 9a94761765c0..3b505006c0a6 100644 --- a/drivers/infiniband/hw/hfi1/user_pages.c +++ b/drivers/infiniband/hw/hfi1/user_pages.c @@ -118,7 +118,7 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np void hfi1_release_user_pages(struct mm_struct *mm, struct page **p, size_t npages, bool dirty) { - put_user_pages_dirty_lock(p, npages, dirty); + unpin_user_pages_dirty_lock(p, npages, dirty); if (mm) { /* during close after signal, mm can be NULL */ atomic64_sub(npages, &mm->pinned_vm); diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c index 8269ab040c21..78a48aea3faf 100644 --- a/drivers/infiniband/hw/mthca/mthca_memfree.c +++ b/drivers/infiniband/hw/mthca/mthca_memfree.c @@ -482,7 +482,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar, ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE); if (ret < 0) { - put_user_page(pages[0]); + unpin_user_page(pages[0]); goto out; } @@ -490,7 +490,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar, mthca_uarc_virt(dev, uar, i)); if (ret) { pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE); - put_user_page(sg_page(&db_tab->page[i].mem)); + unpin_user_page(sg_page(&db_tab->page[i].mem)); goto out; } @@ -556,7 +556,7 @@ void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar, if (db_tab->page[i].uvirt) { mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1); pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE); - put_user_page(sg_page(&db_tab->page[i].mem)); + unpin_user_page(sg_page(&db_tab->page[i].mem)); } } diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c index 7fc4b5f81fcd..342e3172ca40 100644 --- a/drivers/infiniband/hw/qib/qib_user_pages.c +++ b/drivers/infiniband/hw/qib/qib_user_pages.c @@ -40,7 +40,7 @@ static void __qib_release_user_pages(struct page **p, size_t num_pages, int dirty) { - put_user_pages_dirty_lock(p, num_pages, dirty); + unpin_user_pages_dirty_lock(p, num_pages, dirty); } /** diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c index 1a3cc2957e3a..a67599b5a550 100644 --- a/drivers/infiniband/hw/qib/qib_user_sdma.c +++ b/drivers/infiniband/hw/qib/qib_user_sdma.c @@ -317,7 +317,7 @@ static int qib_user_sdma_page_to_frags(const struct qib_devdata *dd, * the caller can ignore this page. */ if (put) { - put_user_page(page); + unpin_user_page(page); } else { /* coalesce case */ kunmap(page); @@ -631,7 +631,7 @@ static void qib_user_sdma_free_pkt_frag(struct device *dev, kunmap(pkt->addr[i].page); if (pkt->addr[i].put_page) - put_user_page(pkt->addr[i].page); + unpin_user_page(pkt->addr[i].page); else __free_page(pkt->addr[i].page); } else if (pkt->addr[i].kvaddr) { @@ -706,7 +706,7 @@ static int qib_user_sdma_pin_pages(const struct qib_devdata *dd, /* if error, return all pages not managed by pkt */ free_pages: while (i < j) - put_user_page(pages[i++]); + unpin_user_page(pages[i++]); done: return ret; diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index 600896727d34..bd9f944b68fc 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -75,7 +75,7 @@ static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty) for_each_sg(chunk->page_list, sg, chunk->nents, i) { page = sg_page(sg); pa = sg_phys(sg); - put_user_pages_dirty_lock(&page, 1, dirty); + unpin_user_pages_dirty_lock(&page, 1, dirty); usnic_dbg("pa: %pa\n", &pa); } kfree(chunk); diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c index e53b07dcfed5..e2061dc0b043 100644 --- a/drivers/infiniband/sw/siw/siw_mem.c +++ b/drivers/infiniband/sw/siw/siw_mem.c @@ -63,7 +63,7 @@ struct siw_mem *siw_mem_id2obj(struct siw_device *sdev, int stag_index) static void siw_free_plist(struct siw_page_chunk *chunk, int num_pages, bool dirty) { - put_user_pages_dirty_lock(chunk->plist, num_pages, dirty); + unpin_user_pages_dirty_lock(chunk->plist, num_pages, dirty); } void siw_umem_release(struct siw_umem *umem, bool dirty) diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c index 162a2633b1e3..13b65ed9e74c 100644 --- a/drivers/media/v4l2-core/videobuf-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf-dma-sg.c @@ -349,8 +349,8 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma) BUG_ON(dma->sglen); if (dma->pages) { - put_user_pages_dirty_lock(dma->pages, dma->nr_pages, - dma->direction == DMA_FROM_DEVICE); + unpin_user_pages_dirty_lock(dma->pages, dma->nr_pages, + dma->direction == DMA_FROM_DEVICE); kfree(dma->pages); dma->pages = NULL; } diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c index 2a5901efecde..1ab207ec9c94 100644 --- a/drivers/platform/goldfish/goldfish_pipe.c +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -360,8 +360,8 @@ static int transfer_max_buffers(struct goldfish_pipe *pipe, *consumed_size = pipe->command_buffer->rw_params.consumed_size; - put_user_pages_dirty_lock(pipe->pages, pages_count, - !is_write && *consumed_size > 0); + unpin_user_pages_dirty_lock(pipe->pages, pages_count, + !is_write && *consumed_size > 0); mutex_unlock(&pipe->lock); return 0; diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 18bfc2fc8e6d..a177bf2c6683 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -310,7 +310,7 @@ static int put_pfn(unsigned long pfn, int prot) if (!is_invalid_reserved_pfn(pfn)) { struct page *page = pfn_to_page(pfn); - put_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE); + unpin_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE); return 1; } return 0; diff --git a/fs/io_uring.c b/fs/io_uring.c index 54f664e8b9b8..1806afddfea5 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6005,7 +6005,7 @@ static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx) struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; for (j = 0; j < imu->nr_bvecs; j++) - put_user_page(imu->bvec[j].bv_page); + unpin_user_page(imu->bvec[j].bv_page); if (ctx->account_mem) io_unaccount_mem(ctx->user, imu->nr_bvecs); @@ -6150,7 +6150,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, * release any pages we did get */ if (pret > 0) - put_user_pages(pages, pret); + unpin_user_pages(pages, pret); if (ctx->account_mem) io_unaccount_mem(ctx->user, nr_pages); kvfree(imu->bvec); diff --git a/include/linux/mm.h b/include/linux/mm.h index 79ca557349c6..fc543eb45de1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1039,27 +1039,27 @@ static inline void put_page(struct page *page) } /** - * put_user_page() - release a gup-pinned page + * unpin_user_page() - release a gup-pinned page * @page: pointer to page to be released * * Pages that were pinned via pin_user_pages*() must be released via either - * put_user_page(), or one of the put_user_pages*() routines. This is so that - * eventually such pages can be separately tracked and uniquely handled. In + * unpin_user_page(), or one of the unpin_user_pages*() routines. This is so + * that eventually such pages can be separately tracked and uniquely handled. In * particular, interactions with RDMA and filesystems need special handling. * - * put_user_page() and put_page() are not interchangeable, despite this early - * implementation that makes them look the same. put_user_page() calls must + * unpin_user_page() and put_page() are not interchangeable, despite this early + * implementation that makes them look the same. unpin_user_page() calls must * be perfectly matched up with pin*() calls. */ -static inline void put_user_page(struct page *page) +static inline void unpin_user_page(struct page *page) { put_page(page); } -void put_user_pages_dirty_lock(struct page **pages, unsigned long npages, - bool make_dirty); +void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, + bool make_dirty); -void put_user_pages(struct page **pages, unsigned long npages); +void unpin_user_pages(struct page **pages, unsigned long npages); #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) #define SECTION_IN_PAGE_FLAGS @@ -2590,7 +2590,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, #define FOLL_ANON 0x8000 /* don't do file mappings */ #define FOLL_LONGTERM 0x10000 /* mapping lifetime is indefinite: see below */ #define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */ -#define FOLL_PIN 0x40000 /* pages must be released via put_user_page() */ +#define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */ /* * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each @@ -2625,7 +2625,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, * Direct IO). This lets the filesystem know that some non-file-system entity is * potentially changing the pages' data. In contrast to FOLL_GET (whose pages * are released via put_page()), FOLL_PIN pages must be released, ultimately, by - * a call to put_user_page(). + * a call to unpin_user_page(). * * FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different * and separate refcounting mechanisms, however, and that means that each has @@ -2633,7 +2633,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, * * FOLL_GET: get_user_pages*() to acquire, and put_page() to release. * - * FOLL_PIN: pin_user_pages*() to acquire, and put_user_pages to release. + * FOLL_PIN: pin_user_pages*() to acquire, and unpin_user_pages to release. * * FOLL_PIN and FOLL_GET are mutually exclusive for a given function call. * (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based @@ -2643,7 +2643,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, * FOLL_PIN should be set internally by the pin_user_pages*() APIs, never * directly by the caller. That's in order to help avoid mismatches when * releasing pages: get_user_pages*() pages must be released via put_page(), - * while pin_user_pages*() pages must be released via put_user_page(). + * while pin_user_pages*() pages must be released via unpin_user_page(). * * Please see Documentation/vm/pin_user_pages.rst for more information. */ diff --git a/mm/gup.c b/mm/gup.c index cc7e78f4a960..e13f4d211475 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -45,7 +45,7 @@ static inline struct page *try_get_compound_head(struct page *page, int refs) } /** - * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages + * unpin_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages * @pages: array of pages to be maybe marked dirty, and definitely released. * @npages: number of pages in the @pages array. * @make_dirty: whether to mark the pages dirty @@ -55,19 +55,19 @@ static inline struct page *try_get_compound_head(struct page *page, int refs) * * For each page in the @pages array, make that page (or its head page, if a * compound page) dirty, if @make_dirty is true, and if the page was previously - * listed as clean. In any case, releases all pages using put_user_page(), - * possibly via put_user_pages(), for the non-dirty case. + * listed as clean. In any case, releases all pages using unpin_user_page(), + * possibly via unpin_user_pages(), for the non-dirty case. * - * Please see the put_user_page() documentation for details. + * Please see the unpin_user_page() documentation for details. * * set_page_dirty_lock() is used internally. If instead, set_page_dirty() is * required, then the caller should a) verify that this is really correct, * because _lock() is usually required, and b) hand code it: - * set_page_dirty_lock(), put_user_page(). + * set_page_dirty_lock(), unpin_user_page(). * */ -void put_user_pages_dirty_lock(struct page **pages, unsigned long npages, - bool make_dirty) +void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, + bool make_dirty) { unsigned long index; @@ -78,7 +78,7 @@ void put_user_pages_dirty_lock(struct page **pages, unsigned long npages, */ if (!make_dirty) { - put_user_pages(pages, npages); + unpin_user_pages(pages, npages); return; } @@ -106,21 +106,21 @@ void put_user_pages_dirty_lock(struct page **pages, unsigned long npages, */ if (!PageDirty(page)) set_page_dirty_lock(page); - put_user_page(page); + unpin_user_page(page); } } -EXPORT_SYMBOL(put_user_pages_dirty_lock); +EXPORT_SYMBOL(unpin_user_pages_dirty_lock); /** - * put_user_pages() - release an array of gup-pinned pages. + * unpin_user_pages() - release an array of gup-pinned pages. * @pages: array of pages to be marked dirty and released. * @npages: number of pages in the @pages array. * - * For each page in the @pages array, release the page using put_user_page(). + * For each page in the @pages array, release the page using unpin_user_page(). * - * Please see the put_user_page() documentation for details. + * Please see the unpin_user_page() documentation for details. */ -void put_user_pages(struct page **pages, unsigned long npages) +void unpin_user_pages(struct page **pages, unsigned long npages) { unsigned long index; @@ -130,9 +130,9 @@ void put_user_pages(struct page **pages, unsigned long npages) * single operation to the head page should suffice. */ for (index = 0; index < npages; index++) - put_user_page(pages[index]); + unpin_user_page(pages[index]); } -EXPORT_SYMBOL(put_user_pages); +EXPORT_SYMBOL(unpin_user_pages); #ifdef CONFIG_MMU static struct page *no_page_table(struct vm_area_struct *vma, diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index fd20ab675b85..de41e830cdac 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -126,8 +126,8 @@ static int process_vm_rw_single_vec(unsigned long addr, pa += pinned_pages * PAGE_SIZE; /* If vm_write is set, the pages need to be made dirty: */ - put_user_pages_dirty_lock(process_pages, pinned_pages, - vm_write); + unpin_user_pages_dirty_lock(process_pages, pinned_pages, + vm_write); } return rc; diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index b17ce9a5534d..fa7bb5e060d0 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -212,7 +212,7 @@ static int xdp_umem_map_pages(struct xdp_umem *umem) static void xdp_umem_unpin_pages(struct xdp_umem *umem) { - put_user_pages_dirty_lock(umem->pgs, umem->npgs, true); + unpin_user_pages_dirty_lock(umem->pgs, umem->npgs, true); kfree(umem->pgs); umem->pgs = NULL; -- cgit