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5b56d49fc3
Patch series "mm: unexport __get_user_pages_unlocked()". This patch series continues the cleanup of get_user_pages*() functions taking advantage of the fact we can now pass gup_flags as we please. It firstly adds an additional 'locked' parameter to get_user_pages_remote() to allow for its callers to utilise VM_FAULT_RETRY functionality. This is necessary as the invocation of __get_user_pages_unlocked() in process_vm_rw_single_vec() makes use of this and no other existing higher level function would allow it to do so. Secondly existing callers of __get_user_pages_unlocked() are replaced with the appropriate higher-level replacement - get_user_pages_unlocked() if the current task and memory descriptor are referenced, or get_user_pages_remote() if other task/memory descriptors are referenced (having acquiring mmap_sem.) This patch (of 2): Add a int *locked parameter to get_user_pages_remote() to allow VM_FAULT_RETRY faulting behaviour similar to get_user_pages_[un]locked(). Taking into account the previous adjustments to get_user_pages*() functions allowing for the passing of gup_flags, we are now in a position where __get_user_pages_unlocked() need only be exported for his ability to allow VM_FAULT_RETRY behaviour, this adjustment allows us to subsequently unexport __get_user_pages_unlocked() as well as allowing for future flexibility in the use of get_user_pages_remote(). [sfr@canb.auug.org.au: merge fix for get_user_pages_remote API change] Link: http://lkml.kernel.org/r/20161122210511.024ec341@canb.auug.org.au Link: http://lkml.kernel.org/r/20161027095141.2569-2-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
673 lines
20 KiB
C
673 lines
20 KiB
C
/*
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* Copyright (c) 2014 Mellanox Technologies. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include <linux/types.h>
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#include <linux/sched.h>
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#include <linux/pid.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include <linux/vmalloc.h>
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#include <rdma/ib_verbs.h>
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#include <rdma/ib_umem.h>
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#include <rdma/ib_umem_odp.h>
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static void ib_umem_notifier_start_account(struct ib_umem *item)
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{
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mutex_lock(&item->odp_data->umem_mutex);
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/* Only update private counters for this umem if it has them.
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* Otherwise skip it. All page faults will be delayed for this umem. */
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if (item->odp_data->mn_counters_active) {
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int notifiers_count = item->odp_data->notifiers_count++;
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if (notifiers_count == 0)
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/* Initialize the completion object for waiting on
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* notifiers. Since notifier_count is zero, no one
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* should be waiting right now. */
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reinit_completion(&item->odp_data->notifier_completion);
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}
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mutex_unlock(&item->odp_data->umem_mutex);
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}
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static void ib_umem_notifier_end_account(struct ib_umem *item)
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{
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mutex_lock(&item->odp_data->umem_mutex);
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/* Only update private counters for this umem if it has them.
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* Otherwise skip it. All page faults will be delayed for this umem. */
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if (item->odp_data->mn_counters_active) {
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/*
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* This sequence increase will notify the QP page fault that
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* the page that is going to be mapped in the spte could have
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* been freed.
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*/
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++item->odp_data->notifiers_seq;
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if (--item->odp_data->notifiers_count == 0)
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complete_all(&item->odp_data->notifier_completion);
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}
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mutex_unlock(&item->odp_data->umem_mutex);
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}
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/* Account for a new mmu notifier in an ib_ucontext. */
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static void ib_ucontext_notifier_start_account(struct ib_ucontext *context)
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{
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atomic_inc(&context->notifier_count);
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}
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/* Account for a terminating mmu notifier in an ib_ucontext.
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*
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* Must be called with the ib_ucontext->umem_rwsem semaphore unlocked, since
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* the function takes the semaphore itself. */
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static void ib_ucontext_notifier_end_account(struct ib_ucontext *context)
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{
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int zero_notifiers = atomic_dec_and_test(&context->notifier_count);
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if (zero_notifiers &&
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!list_empty(&context->no_private_counters)) {
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/* No currently running mmu notifiers. Now is the chance to
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* add private accounting to all previously added umems. */
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struct ib_umem_odp *odp_data, *next;
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/* Prevent concurrent mmu notifiers from working on the
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* no_private_counters list. */
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down_write(&context->umem_rwsem);
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/* Read the notifier_count again, with the umem_rwsem
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* semaphore taken for write. */
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if (!atomic_read(&context->notifier_count)) {
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list_for_each_entry_safe(odp_data, next,
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&context->no_private_counters,
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no_private_counters) {
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mutex_lock(&odp_data->umem_mutex);
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odp_data->mn_counters_active = true;
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list_del(&odp_data->no_private_counters);
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complete_all(&odp_data->notifier_completion);
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mutex_unlock(&odp_data->umem_mutex);
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}
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}
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up_write(&context->umem_rwsem);
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}
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}
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static int ib_umem_notifier_release_trampoline(struct ib_umem *item, u64 start,
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u64 end, void *cookie) {
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/*
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* Increase the number of notifiers running, to
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* prevent any further fault handling on this MR.
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*/
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ib_umem_notifier_start_account(item);
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item->odp_data->dying = 1;
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/* Make sure that the fact the umem is dying is out before we release
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* all pending page faults. */
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smp_wmb();
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complete_all(&item->odp_data->notifier_completion);
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item->context->invalidate_range(item, ib_umem_start(item),
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ib_umem_end(item));
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return 0;
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}
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static void ib_umem_notifier_release(struct mmu_notifier *mn,
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struct mm_struct *mm)
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{
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struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);
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if (!context->invalidate_range)
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return;
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ib_ucontext_notifier_start_account(context);
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down_read(&context->umem_rwsem);
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rbt_ib_umem_for_each_in_range(&context->umem_tree, 0,
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ULLONG_MAX,
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ib_umem_notifier_release_trampoline,
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NULL);
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up_read(&context->umem_rwsem);
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}
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static int invalidate_page_trampoline(struct ib_umem *item, u64 start,
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u64 end, void *cookie)
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{
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ib_umem_notifier_start_account(item);
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item->context->invalidate_range(item, start, start + PAGE_SIZE);
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ib_umem_notifier_end_account(item);
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return 0;
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}
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static void ib_umem_notifier_invalidate_page(struct mmu_notifier *mn,
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struct mm_struct *mm,
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unsigned long address)
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{
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struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);
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if (!context->invalidate_range)
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return;
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ib_ucontext_notifier_start_account(context);
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down_read(&context->umem_rwsem);
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rbt_ib_umem_for_each_in_range(&context->umem_tree, address,
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address + PAGE_SIZE,
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invalidate_page_trampoline, NULL);
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up_read(&context->umem_rwsem);
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ib_ucontext_notifier_end_account(context);
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}
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static int invalidate_range_start_trampoline(struct ib_umem *item, u64 start,
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u64 end, void *cookie)
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{
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ib_umem_notifier_start_account(item);
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item->context->invalidate_range(item, start, end);
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return 0;
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}
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static void ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn,
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struct mm_struct *mm,
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unsigned long start,
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unsigned long end)
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{
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struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);
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if (!context->invalidate_range)
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return;
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ib_ucontext_notifier_start_account(context);
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down_read(&context->umem_rwsem);
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rbt_ib_umem_for_each_in_range(&context->umem_tree, start,
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end,
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invalidate_range_start_trampoline, NULL);
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up_read(&context->umem_rwsem);
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}
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static int invalidate_range_end_trampoline(struct ib_umem *item, u64 start,
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u64 end, void *cookie)
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{
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ib_umem_notifier_end_account(item);
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return 0;
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}
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static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn,
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struct mm_struct *mm,
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unsigned long start,
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unsigned long end)
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{
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struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);
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if (!context->invalidate_range)
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return;
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down_read(&context->umem_rwsem);
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rbt_ib_umem_for_each_in_range(&context->umem_tree, start,
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end,
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invalidate_range_end_trampoline, NULL);
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up_read(&context->umem_rwsem);
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ib_ucontext_notifier_end_account(context);
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}
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static const struct mmu_notifier_ops ib_umem_notifiers = {
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.release = ib_umem_notifier_release,
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.invalidate_page = ib_umem_notifier_invalidate_page,
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.invalidate_range_start = ib_umem_notifier_invalidate_range_start,
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.invalidate_range_end = ib_umem_notifier_invalidate_range_end,
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};
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int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem)
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{
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int ret_val;
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struct pid *our_pid;
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struct mm_struct *mm = get_task_mm(current);
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if (!mm)
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return -EINVAL;
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/* Prevent creating ODP MRs in child processes */
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rcu_read_lock();
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our_pid = get_task_pid(current->group_leader, PIDTYPE_PID);
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rcu_read_unlock();
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put_pid(our_pid);
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if (context->tgid != our_pid) {
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ret_val = -EINVAL;
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goto out_mm;
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}
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umem->hugetlb = 0;
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umem->odp_data = kzalloc(sizeof(*umem->odp_data), GFP_KERNEL);
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if (!umem->odp_data) {
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ret_val = -ENOMEM;
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goto out_mm;
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}
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umem->odp_data->umem = umem;
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mutex_init(&umem->odp_data->umem_mutex);
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init_completion(&umem->odp_data->notifier_completion);
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umem->odp_data->page_list = vzalloc(ib_umem_num_pages(umem) *
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sizeof(*umem->odp_data->page_list));
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if (!umem->odp_data->page_list) {
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ret_val = -ENOMEM;
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goto out_odp_data;
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}
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umem->odp_data->dma_list = vzalloc(ib_umem_num_pages(umem) *
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sizeof(*umem->odp_data->dma_list));
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if (!umem->odp_data->dma_list) {
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ret_val = -ENOMEM;
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goto out_page_list;
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}
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/*
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* When using MMU notifiers, we will get a
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* notification before the "current" task (and MM) is
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* destroyed. We use the umem_rwsem semaphore to synchronize.
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*/
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down_write(&context->umem_rwsem);
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context->odp_mrs_count++;
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if (likely(ib_umem_start(umem) != ib_umem_end(umem)))
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rbt_ib_umem_insert(&umem->odp_data->interval_tree,
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&context->umem_tree);
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if (likely(!atomic_read(&context->notifier_count)) ||
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context->odp_mrs_count == 1)
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umem->odp_data->mn_counters_active = true;
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else
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list_add(&umem->odp_data->no_private_counters,
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&context->no_private_counters);
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downgrade_write(&context->umem_rwsem);
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if (context->odp_mrs_count == 1) {
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/*
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* Note that at this point, no MMU notifier is running
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* for this context!
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*/
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atomic_set(&context->notifier_count, 0);
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INIT_HLIST_NODE(&context->mn.hlist);
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context->mn.ops = &ib_umem_notifiers;
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/*
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* Lock-dep detects a false positive for mmap_sem vs.
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* umem_rwsem, due to not grasping downgrade_write correctly.
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*/
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lockdep_off();
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ret_val = mmu_notifier_register(&context->mn, mm);
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lockdep_on();
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if (ret_val) {
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pr_err("Failed to register mmu_notifier %d\n", ret_val);
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ret_val = -EBUSY;
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goto out_mutex;
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}
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}
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up_read(&context->umem_rwsem);
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/*
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* Note that doing an mmput can cause a notifier for the relevant mm.
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* If the notifier is called while we hold the umem_rwsem, this will
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* cause a deadlock. Therefore, we release the reference only after we
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* released the semaphore.
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*/
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mmput(mm);
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return 0;
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out_mutex:
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up_read(&context->umem_rwsem);
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vfree(umem->odp_data->dma_list);
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out_page_list:
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vfree(umem->odp_data->page_list);
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out_odp_data:
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kfree(umem->odp_data);
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out_mm:
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mmput(mm);
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return ret_val;
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}
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void ib_umem_odp_release(struct ib_umem *umem)
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{
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struct ib_ucontext *context = umem->context;
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/*
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* Ensure that no more pages are mapped in the umem.
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*
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* It is the driver's responsibility to ensure, before calling us,
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* that the hardware will not attempt to access the MR any more.
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*/
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ib_umem_odp_unmap_dma_pages(umem, ib_umem_start(umem),
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ib_umem_end(umem));
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down_write(&context->umem_rwsem);
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if (likely(ib_umem_start(umem) != ib_umem_end(umem)))
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rbt_ib_umem_remove(&umem->odp_data->interval_tree,
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&context->umem_tree);
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context->odp_mrs_count--;
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if (!umem->odp_data->mn_counters_active) {
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list_del(&umem->odp_data->no_private_counters);
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complete_all(&umem->odp_data->notifier_completion);
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}
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/*
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* Downgrade the lock to a read lock. This ensures that the notifiers
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* (who lock the mutex for reading) will be able to finish, and we
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* will be able to enventually obtain the mmu notifiers SRCU. Note
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* that since we are doing it atomically, no other user could register
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* and unregister while we do the check.
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*/
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downgrade_write(&context->umem_rwsem);
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if (!context->odp_mrs_count) {
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struct task_struct *owning_process = NULL;
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struct mm_struct *owning_mm = NULL;
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owning_process = get_pid_task(context->tgid,
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PIDTYPE_PID);
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if (owning_process == NULL)
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/*
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* The process is already dead, notifier were removed
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* already.
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*/
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goto out;
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owning_mm = get_task_mm(owning_process);
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if (owning_mm == NULL)
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/*
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* The process' mm is already dead, notifier were
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* removed already.
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*/
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goto out_put_task;
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mmu_notifier_unregister(&context->mn, owning_mm);
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mmput(owning_mm);
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out_put_task:
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put_task_struct(owning_process);
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}
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out:
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up_read(&context->umem_rwsem);
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vfree(umem->odp_data->dma_list);
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vfree(umem->odp_data->page_list);
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kfree(umem->odp_data);
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kfree(umem);
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}
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/*
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* Map for DMA and insert a single page into the on-demand paging page tables.
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*
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* @umem: the umem to insert the page to.
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* @page_index: index in the umem to add the page to.
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* @page: the page struct to map and add.
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* @access_mask: access permissions needed for this page.
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* @current_seq: sequence number for synchronization with invalidations.
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* the sequence number is taken from
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* umem->odp_data->notifiers_seq.
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*
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* The function returns -EFAULT if the DMA mapping operation fails. It returns
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* -EAGAIN if a concurrent invalidation prevents us from updating the page.
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*
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* The page is released via put_page even if the operation failed. For
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* on-demand pinning, the page is released whenever it isn't stored in the
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* umem.
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*/
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static int ib_umem_odp_map_dma_single_page(
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struct ib_umem *umem,
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int page_index,
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u64 base_virt_addr,
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struct page *page,
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u64 access_mask,
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unsigned long current_seq)
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{
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struct ib_device *dev = umem->context->device;
|
|
dma_addr_t dma_addr;
|
|
int stored_page = 0;
|
|
int remove_existing_mapping = 0;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* Note: we avoid writing if seq is different from the initial seq, to
|
|
* handle case of a racing notifier. This check also allows us to bail
|
|
* early if we have a notifier running in parallel with us.
|
|
*/
|
|
if (ib_umem_mmu_notifier_retry(umem, current_seq)) {
|
|
ret = -EAGAIN;
|
|
goto out;
|
|
}
|
|
if (!(umem->odp_data->dma_list[page_index])) {
|
|
dma_addr = ib_dma_map_page(dev,
|
|
page,
|
|
0, PAGE_SIZE,
|
|
DMA_BIDIRECTIONAL);
|
|
if (ib_dma_mapping_error(dev, dma_addr)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
umem->odp_data->dma_list[page_index] = dma_addr | access_mask;
|
|
umem->odp_data->page_list[page_index] = page;
|
|
stored_page = 1;
|
|
} else if (umem->odp_data->page_list[page_index] == page) {
|
|
umem->odp_data->dma_list[page_index] |= access_mask;
|
|
} else {
|
|
pr_err("error: got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n",
|
|
umem->odp_data->page_list[page_index], page);
|
|
/* Better remove the mapping now, to prevent any further
|
|
* damage. */
|
|
remove_existing_mapping = 1;
|
|
}
|
|
|
|
out:
|
|
/* On Demand Paging - avoid pinning the page */
|
|
if (umem->context->invalidate_range || !stored_page)
|
|
put_page(page);
|
|
|
|
if (remove_existing_mapping && umem->context->invalidate_range) {
|
|
invalidate_page_trampoline(
|
|
umem,
|
|
base_virt_addr + (page_index * PAGE_SIZE),
|
|
base_virt_addr + ((page_index+1)*PAGE_SIZE),
|
|
NULL);
|
|
ret = -EAGAIN;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* ib_umem_odp_map_dma_pages - Pin and DMA map userspace memory in an ODP MR.
|
|
*
|
|
* Pins the range of pages passed in the argument, and maps them to
|
|
* DMA addresses. The DMA addresses of the mapped pages is updated in
|
|
* umem->odp_data->dma_list.
|
|
*
|
|
* Returns the number of pages mapped in success, negative error code
|
|
* for failure.
|
|
* An -EAGAIN error code is returned when a concurrent mmu notifier prevents
|
|
* the function from completing its task.
|
|
*
|
|
* @umem: the umem to map and pin
|
|
* @user_virt: the address from which we need to map.
|
|
* @bcnt: the minimal number of bytes to pin and map. The mapping might be
|
|
* bigger due to alignment, and may also be smaller in case of an error
|
|
* pinning or mapping a page. The actual pages mapped is returned in
|
|
* the return value.
|
|
* @access_mask: bit mask of the requested access permissions for the given
|
|
* range.
|
|
* @current_seq: the MMU notifiers sequance value for synchronization with
|
|
* invalidations. the sequance number is read from
|
|
* umem->odp_data->notifiers_seq before calling this function
|
|
*/
|
|
int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt,
|
|
u64 access_mask, unsigned long current_seq)
|
|
{
|
|
struct task_struct *owning_process = NULL;
|
|
struct mm_struct *owning_mm = NULL;
|
|
struct page **local_page_list = NULL;
|
|
u64 off;
|
|
int j, k, ret = 0, start_idx, npages = 0;
|
|
u64 base_virt_addr;
|
|
unsigned int flags = 0;
|
|
|
|
if (access_mask == 0)
|
|
return -EINVAL;
|
|
|
|
if (user_virt < ib_umem_start(umem) ||
|
|
user_virt + bcnt > ib_umem_end(umem))
|
|
return -EFAULT;
|
|
|
|
local_page_list = (struct page **)__get_free_page(GFP_KERNEL);
|
|
if (!local_page_list)
|
|
return -ENOMEM;
|
|
|
|
off = user_virt & (~PAGE_MASK);
|
|
user_virt = user_virt & PAGE_MASK;
|
|
base_virt_addr = user_virt;
|
|
bcnt += off; /* Charge for the first page offset as well. */
|
|
|
|
owning_process = get_pid_task(umem->context->tgid, PIDTYPE_PID);
|
|
if (owning_process == NULL) {
|
|
ret = -EINVAL;
|
|
goto out_no_task;
|
|
}
|
|
|
|
owning_mm = get_task_mm(owning_process);
|
|
if (owning_mm == NULL) {
|
|
ret = -EINVAL;
|
|
goto out_put_task;
|
|
}
|
|
|
|
if (access_mask & ODP_WRITE_ALLOWED_BIT)
|
|
flags |= FOLL_WRITE;
|
|
|
|
start_idx = (user_virt - ib_umem_start(umem)) >> PAGE_SHIFT;
|
|
k = start_idx;
|
|
|
|
while (bcnt > 0) {
|
|
const size_t gup_num_pages =
|
|
min_t(size_t, ALIGN(bcnt, PAGE_SIZE) / PAGE_SIZE,
|
|
PAGE_SIZE / sizeof(struct page *));
|
|
|
|
down_read(&owning_mm->mmap_sem);
|
|
/*
|
|
* Note: this might result in redundent page getting. We can
|
|
* avoid this by checking dma_list to be 0 before calling
|
|
* get_user_pages. However, this make the code much more
|
|
* complex (and doesn't gain us much performance in most use
|
|
* cases).
|
|
*/
|
|
npages = get_user_pages_remote(owning_process, owning_mm,
|
|
user_virt, gup_num_pages,
|
|
flags, local_page_list, NULL, NULL);
|
|
up_read(&owning_mm->mmap_sem);
|
|
|
|
if (npages < 0)
|
|
break;
|
|
|
|
bcnt -= min_t(size_t, npages << PAGE_SHIFT, bcnt);
|
|
user_virt += npages << PAGE_SHIFT;
|
|
mutex_lock(&umem->odp_data->umem_mutex);
|
|
for (j = 0; j < npages; ++j) {
|
|
ret = ib_umem_odp_map_dma_single_page(
|
|
umem, k, base_virt_addr, local_page_list[j],
|
|
access_mask, current_seq);
|
|
if (ret < 0)
|
|
break;
|
|
k++;
|
|
}
|
|
mutex_unlock(&umem->odp_data->umem_mutex);
|
|
|
|
if (ret < 0) {
|
|
/* Release left over pages when handling errors. */
|
|
for (++j; j < npages; ++j)
|
|
put_page(local_page_list[j]);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (ret >= 0) {
|
|
if (npages < 0 && k == start_idx)
|
|
ret = npages;
|
|
else
|
|
ret = k - start_idx;
|
|
}
|
|
|
|
mmput(owning_mm);
|
|
out_put_task:
|
|
put_task_struct(owning_process);
|
|
out_no_task:
|
|
free_page((unsigned long)local_page_list);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(ib_umem_odp_map_dma_pages);
|
|
|
|
void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt,
|
|
u64 bound)
|
|
{
|
|
int idx;
|
|
u64 addr;
|
|
struct ib_device *dev = umem->context->device;
|
|
|
|
virt = max_t(u64, virt, ib_umem_start(umem));
|
|
bound = min_t(u64, bound, ib_umem_end(umem));
|
|
/* Note that during the run of this function, the
|
|
* notifiers_count of the MR is > 0, preventing any racing
|
|
* faults from completion. We might be racing with other
|
|
* invalidations, so we must make sure we free each page only
|
|
* once. */
|
|
mutex_lock(&umem->odp_data->umem_mutex);
|
|
for (addr = virt; addr < bound; addr += (u64)umem->page_size) {
|
|
idx = (addr - ib_umem_start(umem)) / PAGE_SIZE;
|
|
if (umem->odp_data->page_list[idx]) {
|
|
struct page *page = umem->odp_data->page_list[idx];
|
|
dma_addr_t dma = umem->odp_data->dma_list[idx];
|
|
dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK;
|
|
|
|
WARN_ON(!dma_addr);
|
|
|
|
ib_dma_unmap_page(dev, dma_addr, PAGE_SIZE,
|
|
DMA_BIDIRECTIONAL);
|
|
if (dma & ODP_WRITE_ALLOWED_BIT) {
|
|
struct page *head_page = compound_head(page);
|
|
/*
|
|
* set_page_dirty prefers being called with
|
|
* the page lock. However, MMU notifiers are
|
|
* called sometimes with and sometimes without
|
|
* the lock. We rely on the umem_mutex instead
|
|
* to prevent other mmu notifiers from
|
|
* continuing and allowing the page mapping to
|
|
* be removed.
|
|
*/
|
|
set_page_dirty(head_page);
|
|
}
|
|
/* on demand pinning support */
|
|
if (!umem->context->invalidate_range)
|
|
put_page(page);
|
|
umem->odp_data->page_list[idx] = NULL;
|
|
umem->odp_data->dma_list[idx] = 0;
|
|
}
|
|
}
|
|
mutex_unlock(&umem->odp_data->umem_mutex);
|
|
}
|
|
EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages);
|