+ accel-amdxdna-use-hmm_range_fault_unlocked_timeout-for-range-population.patch added to mm-unstable branch

+ accel-amdxdna-use-hmm_range_fault_unlocked_timeout-for-range-population.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: accel/amdxdna: use hmm_range_fault_unlocked_timeout() for range population
has been added to the -mm mm-unstable branch.  Its filename is
     accel-amdxdna-use-hmm_range_fault_unlocked_timeout-for-range-population.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/accel-amdxdna-use-hmm_range_fault_unlocked_timeout-for-range-population.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Stanislav Kinsburskii <skinsburskii@gmail.com>
Subject: accel/amdxdna: use hmm_range_fault_unlocked_timeout() for range population
Date: Wed, 15 Jul 2026 11:16:44 -0700

aie2_populate_range() takes mmap_read_lock() only around
hmm_range_fault().  It also open-codes the mmu interval sequence setup
before each HMM walk and 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 mapp->range.notifier_seq for its internal
retries, so the driver only needs to call the helper and then validate the
sequence before marking the mapping populated.

Pass HMM_RANGE_DEFAULT_TIMEOUT as the helper retry budget for each HMM
population attempt.  This scopes the timeout to repeated HMM notifier
retries while preserving the existing outer loop that moves between
invalid mappings and restarts when the interval is invalidated before the
driver updates its mapping state.

Keep returning -ETIME when the HMM retry budget expires, matching the
driver's existing timeout error convention.

Link: https://lore.kernel.org/178413940486.1155966.10368807598827608499.stgit@skinsburskii
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: Kees Cook <kees@kernel.org>
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: Oleg Nesterov <oleg@redhat.com>
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>
---

 drivers/accel/amdxdna/aie2_ctx.c |   23 ++++-------------------
 1 file changed, 4 insertions(+), 19 deletions(-)

--- a/drivers/accel/amdxdna/aie2_ctx.c~accel-amdxdna-use-hmm_range_fault_unlocked_timeout-for-range-population
+++ a/drivers/accel/amdxdna/aie2_ctx.c
@@ -1034,7 +1034,7 @@ static int aie2_populate_range(struct am
 	bool found;
 	int ret;
 
-	timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
+	timeout = msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
 again:
 	found = false;
 	down_write(&xdna->notifier_lock);
@@ -1061,24 +1061,9 @@ again:
 		return -EFAULT;
 	}
 
-	mapp->range.notifier_seq = mmu_interval_read_begin(&mapp->notifier);
-	mmap_read_lock(mm);
-	ret = hmm_range_fault(&mapp->range);
-	mmap_read_unlock(mm);
-	if (ret) {
-		if (time_after(jiffies, timeout)) {
-			ret = -ETIME;
-			goto put_mm;
-		}
-
-		if (ret == -EBUSY) {
-			amdxdna_umap_put(mapp);
-			mmput(mm);
-			goto again;
-		}
-
+	ret = hmm_range_fault_unlocked_timeout(&mapp->range, timeout);
+	if (ret)
 		goto put_mm;
-	}
 
 	down_write(&xdna->notifier_lock);
 	if (mmu_interval_read_retry(&mapp->notifier, mapp->range.notifier_seq)) {
@@ -1096,7 +1081,7 @@ again:
 put_mm:
 	amdxdna_umap_put(mapp);
 	mmput(mm);
-	return ret;
+	return ret == -EBUSY ? -ETIME : ret;
 }
 
 int aie2_cmd_submit(struct amdxdna_hwctx *hwctx, struct amdxdna_sched_job *job, u64 *seq)
_

Patches currently in -mm which might be from skinsburskii@gmail.com are

lib-test_hmm-use-device-devt-for-coherent-device-range-selection.patch
mm-hmm-move-page-fault-handling-out-of-walk-callbacks.patch
mm-hmm-add-hmm_range_fault_unlocked_timeout-for-mmap-lock-drop-support.patch
selftests-mm-add-hmm-test-for-mmap-lock-dropping-faults.patch
mshv-use-hmm_range_fault_unlocked_timeout-for-region-faults.patch
drm-nouveau-use-hmm_range_fault_unlocked_timeout-for-svm-faults.patch
rdma-umem-use-hmm_range_fault_unlocked_timeout-for-odp-faults.patch
accel-amdxdna-use-hmm_range_fault_unlocked_timeout-for-range-population.patch
drm-gpusvm-use-hmm_range_fault_unlocked_timeout-for-range-faults.patch