linux-kernel - [PATCH 1/2] habanalabs: remove dead code from free_device

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Message-Id: <20220626103304.46126-1-ogabbay@kernel.org>
Date:   Sun, 26 Jun 2022 13:33:03 +0300
From:   Oded Gabbay <ogabbay@...nel.org>
To:     linux-kernel@...r.kernel.org
Cc:     Tomer Tayar <ttayar@...ana.ai>
Subject: [PATCH 1/2] habanalabs: remove dead code from free_device_memory()

From: Tomer Tayar <ttayar@...ana.ai>

free_device_memory() ends with if and else, each has a return statement,
followed by another return statement that can never be reached.
Restructure the function and remove this dead code.

Signed-off-by: Tomer Tayar <ttayar@...ana.ai>
Reviewed-by: Oded Gabbay <ogabbay@...nel.org>
Signed-off-by: Oded Gabbay <ogabbay@...nel.org>
---
 drivers/misc/habanalabs/common/memory.c | 50 +++++++++++--------------
 1 file changed, 22 insertions(+), 28 deletions(-)

diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
index 4f35a5668fcb..bc921f32716a 100644
--- a/drivers/misc/habanalabs/common/memory.c
+++ b/drivers/misc/habanalabs/common/memory.c
@@ -359,41 +359,35 @@ static int free_device_memory(struct hl_ctx *ctx, struct hl_mem_in *args)
 
 	spin_lock(&vm->idr_lock);
 	phys_pg_pack = idr_find(&vm->phys_pg_pack_handles, handle);
-	if (phys_pg_pack) {
-		if (atomic_read(&phys_pg_pack->mapping_cnt) > 0) {
-			dev_err(hdev->dev, "handle %u is mapped, cannot free\n",
-				handle);
-			spin_unlock(&vm->idr_lock);
-			return -EINVAL;
-		}
-
-		if (phys_pg_pack->exporting_cnt) {
-			dev_dbg(hdev->dev, "handle %u is exported, cannot free\n", handle);
-			spin_unlock(&vm->idr_lock);
-			return -EINVAL;
-		}
-
-		/*
-		 * must remove from idr before the freeing of the physical
-		 * pages as the refcount of the pool is also the trigger of the
-		 * idr destroy
-		 */
-		idr_remove(&vm->phys_pg_pack_handles, handle);
+	if (!phys_pg_pack) {
 		spin_unlock(&vm->idr_lock);
+		dev_err(hdev->dev, "free device memory failed, no match for handle %u\n", handle);
+		return -EINVAL;
+	}
 
-		atomic64_sub(phys_pg_pack->total_size, &ctx->dram_phys_mem);
-		atomic64_sub(phys_pg_pack->total_size, &hdev->dram_used_mem);
+	if (atomic_read(&phys_pg_pack->mapping_cnt) > 0) {
+		spin_unlock(&vm->idr_lock);
+		dev_err(hdev->dev, "handle %u is mapped, cannot free\n", handle);
+		return -EINVAL;
+	}
 
-		free_phys_pg_pack(hdev, phys_pg_pack);
-		return 0;
-	} else {
+	if (phys_pg_pack->exporting_cnt) {
 		spin_unlock(&vm->idr_lock);
-		dev_err(hdev->dev,
-			"free device memory failed, no match for handle %u\n",
-			handle);
+		dev_dbg(hdev->dev, "handle %u is exported, cannot free\n", handle);
 		return -EINVAL;
 	}
 
+	/* must remove from idr before the freeing of the physical pages as the refcount of the pool
+	 * is also the trigger of the idr destroy
+	 */
+	idr_remove(&vm->phys_pg_pack_handles, handle);
+	spin_unlock(&vm->idr_lock);
+
+	atomic64_sub(phys_pg_pack->total_size, &ctx->dram_phys_mem);
+	atomic64_sub(phys_pg_pack->total_size, &hdev->dram_used_mem);
+
+	free_phys_pg_pack(hdev, phys_pg_pack);
+
 	return 0;
 }
 
-- 
2.25.1