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path: root/drivers/infiniband/hw/hfi1/mmu_rb.c
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2016-12-11IB/hfi1: constify mmu_notifier_ops structureBhumika Goyal
Declare the structure mmu_notifier_ops as const as it is only stored in the ops field of a mmu_notifier structure. The ops field is of type const struct mmu_notifier_ops *, so mmu_notifier_ops structures having this property can be declared as const. Done using coccinelle: @r1 disable optional_qualifier @ identifier i; position p; @@ static struct mmu_notifier_ops i@p = {...}; @ok1@ identifier r1.i; position p; struct mmu_rb_handler handler; @@ handler.mn.ops=&i@p @bad@ position p!={r1.p,ok1.p}; identifier r1.i; @@ i@p @depends on !bad disable optional_qualifier@ identifier r1.i; @@ static +const struct mmu_notifier_ops i={...}; @depends on !bad disable optional_qualifier@ identifier r1.i; @@ +const struct mmu_notifier_ops i; File size before: text data bss dec hex filename 3566 72 16 3654 e46 drivers/infiniband/hw/hfi1/mmu_rb.o File size after: text data bss dec hex filename 3658 0 16 3674 e5a drivers/infiniband/hw/hfi1/mmu_rb.o Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Add cache evict LRU listDean Luick
The original code used a LRU list to evict nodes which were least recently used. For correctness the evict code was moved under the handler->lock, now add back the LRU list. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Remove unneeded mm argument in remove functionDean Luick
The reworked mmu_rb interface allows the unused mm argument to be removed. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Consistently call ops->remove outside spinlockDean Luick
The ops->remove() callback was called by hfi1_mmu_unregister() with a NULL mm argument while holding a spinlock. In the case of sdma_rb_remove() this caused it to pass current->mm to hfi1_release_user_pages() This had 2 problems. First this would attempt to acquire the mmap_sem under a spin lock. Second the use of current->mm is not always guaranteed to be the proper mm when the fd is being closed. Rather than depend on this implicit behavior we move all calls to ops->remove outside of the spinlock. This also allows the correct mm to be used in the remove callback without fear of deadlock. Because the MMU notifier is not guaranteed to hold mm->mmap_sem, but usually does, we must delay all remove callbacks until out of the notifier, when the callbacks can take the mmap_sem if they need to. Code comments were added to clarify what the expectations are for the users of the mmu rb tree. Suggested-by: Jim Foraker <foraker1@llnl.gov> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Add evict operation to the mmu rb handlerDean Luick
Allow users to clear nodes from the rb tree based on their evict callback. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Make the cache handler own its rb tree rootDean Luick
The objects which use cache handling should reference their own handler object not the internal data structure it uses to track the nodes. Have the "users" of the mmu notifier code pass opaque objects which can then be properly used in the mmu callbacks depending on the owners needs. This patch has the additional benefit that operations no longer require a look up in a list to find the handlers. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Make use of mm consistentIra Weiny
The hfi1 driver registers a mmu_notifier callback when /dev/hfi1_* is opened, and unregisters it when the device is closed. The driver incorrectly assumes that the close will always happen from the same context as the open. In particular, closes due to SIGKILL or OOM killer activity may happen from a different context. In these cases, the wrong mm is passed to mmu_notifier_unregister(), which causes improper reference counting for the victim mm, and eventual memory corruption. Preserve the mm for all open file descriptors and use this mm rather than current->mm for memory operations for the lifetime of that fd. Note: this patch leaves 1 use of current->mm in place. This use is removed in a follow on patch because other functional changes were required prior to that use being removed. If registration fails, there is no reason to keep the handler object around. Free the handler object rather than add it to the list to prevent any mmu_notifier operations, including unregister, when registration fails. Suggested-by: Jim Foraker <foraker1@llnl.gov> Reviewed-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Remove unneeded empty check in hfi1_mmu_rb_unregister()Dean Luick
Checking if the rb tree is empty is redundant with the while loop which is emptying the rb tree. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Consolidate __mmu_rb_remove and hfi1_mmu_rb_removeIra Weiny
__mmu_rb_remove was called in only 1 place which was a very simple call site. Combine this function into its caller. Reviewed-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Always expect ops functionsDean Luick
Remove, insert, and invalidate are always provided. No need to test. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02IB/hfi1: Remove unused function hfi1_mmu_rb_searchDean Luick
Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-05-26IB/hfi1: Move driver out of stagingDennis Dalessandro
The TODO list for the hfi1 driver was completed during 4.6. In addition other objections raised (which are far beyond what was in the TODO list) have been addressed as well. It is now time to remove the driver from staging and into the drivers/infiniband sub-tree. Reviewed-by: Jubin John <jubin.john@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>