RDMA/umem: use hmm_range_fault_unlocked_timeout() for ODP faults

ib_umem_odp_map_dma_and_lock() takes mmap_read_lock() only around
hmm_range_fault(), then retries -EBUSY until HMM_RANGE_DEFAULT_TIMEOUT
expires.

Use hmm_range_fault_unlocked_timeout() instead.  The HMM helper now owns
the mmap lock and refreshes range->notifier_seq for its internal retries. 
ODP keeps using HMM_RANGE_DEFAULT_TIMEOUT for each HMM fault attempt,
while interval invalidation retries continue to be handled by the existing
outer loop.

ODP still validates the interval notifier sequence while holding
umem_mutex before DMA mapping pages.

Link: https://lore.kernel.org/20260723-hmm-v10-v11-6-c55b003a4b61@gmail.com
Signed-off-by: Stanislav Kinsburskii <skinsburskii@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lizhi Hou <lizhi.hou@amd.com>
Cc: Long Li <longli@microsoft.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Lyude <lyude@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oded Gabbay <ogabbay@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 5 insertions, 13 deletions

diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index 404fa1cc3254..9cc21cd762d9 100644
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -329,7 +329,7 @@ int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *umem_odp, u64 user_virt,
 	struct mm_struct *owning_mm = umem_odp->umem.owning_mm;
 	int pfn_index, dma_index, ret = 0, start_idx;
 	unsigned int page_shift, hmm_order, pfn_start_idx;
-	unsigned long num_pfns, current_seq;
+	unsigned long num_pfns;
 	struct hmm_range range = {};
 	unsigned long timeout;
 
@@ -363,26 +363,18 @@ int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *umem_odp, u64 user_virt,
 	}
 
 	range.hmm_pfns = &(umem_odp->map.pfn_list[pfn_start_idx]);
-	timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
+	timeout = msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
 
 retry:
-	current_seq = range.notifier_seq =
-		mmu_interval_read_begin(&umem_odp->notifier);
-
-	mmap_read_lock(owning_mm);
-	ret = hmm_range_fault(&range);
-	mmap_read_unlock(owning_mm);
-	if (unlikely(ret)) {
-		if (ret == -EBUSY && !time_after(jiffies, timeout))
-			goto retry;
+	ret = hmm_range_fault_unlocked_timeout(&range, timeout);
+	if (unlikely(ret))
 		goto out_put_mm;
-	}
 
 	start_idx = (range.start - ib_umem_start(umem_odp)) >> page_shift;
 	dma_index = start_idx;
 
 	mutex_lock(&umem_odp->umem_mutex);
-	if (mmu_interval_read_retry(&umem_odp->notifier, current_seq)) {
+	if (mmu_interval_read_retry(&umem_odp->notifier, range.notifier_seq)) {
 		mutex_unlock(&umem_odp->umem_mutex);
 		goto retry;
 	}