[PATCH v10 7/8] accel/amdxdna: Use hmm_range_fault_unlocked_timeout() for range population

[Stanislav Kinsburskii <skinsburskii@gmail.com>]

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.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Stanislav Kinsburskii <skinsburskii@gmail.com>
---
 drivers/accel/amdxdna/aie2_ctx.c | 23 ++++-------------------
 1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/drivers/accel/amdxdna/aie2_ctx.c b/drivers/accel/amdxdna/aie2_ctx.c
index 54486960cbf5..b5b4ca263002 100644
--- a/drivers/accel/amdxdna/aie2_ctx.c
+++ b/drivers/accel/amdxdna/aie2_ctx.c
@@ -1034,7 +1034,7 @@ static int aie2_populate_range(struct amdxdna_gem_obj *abo)
 	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 @@ static int aie2_populate_range(struct amdxdna_gem_obj *abo)
 		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 @@ static int aie2_populate_range(struct amdxdna_gem_obj *abo)
 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)

-- 
2.43.0