[PATCH v3 5/6] powerpc: powernv: ocxl: use lock guard for mutex

[Shrikanth Hegde <sshegde@linux.ibm.com>]

use guard(mutex) for scope based resource management of mutex.
This would make the code simpler and easier to maintain.

More details on lock guards can be found at
https://lore.kernel.org/all/20230612093537.614161713@infradead.org/T/#u

Reviewed-by: Srikar Dronamraju <srikar@linux.ibm.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
---
 arch/powerpc/platforms/powernv/ocxl.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/ocxl.c b/arch/powerpc/platforms/powernv/ocxl.c
index 64a9c7125c29..f8139948348e 100644
--- a/arch/powerpc/platforms/powernv/ocxl.c
+++ b/arch/powerpc/platforms/powernv/ocxl.c
@@ -172,12 +172,11 @@ static void pnv_ocxl_fixup_actag(struct pci_dev *dev)
 	if (phb->type != PNV_PHB_NPU_OCAPI)
 		return;
 
-	mutex_lock(&links_list_lock);
+	guard(mutex)(&links_list_lock);
 
 	link = find_link(dev);
 	if (!link) {
 		dev_warn(&dev->dev, "couldn't update actag information\n");
-		mutex_unlock(&links_list_lock);
 		return;
 	}
 
@@ -206,7 +205,6 @@ static void pnv_ocxl_fixup_actag(struct pci_dev *dev)
 	dev_dbg(&dev->dev, "total actags for function: %d\n",
 		link->fn_desired_actags[PCI_FUNC(dev->devfn)]);
 
-	mutex_unlock(&links_list_lock);
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pnv_ocxl_fixup_actag);
 
@@ -253,12 +251,11 @@ int pnv_ocxl_get_actag(struct pci_dev *dev, u16 *base, u16 *enabled,
 {
 	struct npu_link *link;
 
-	mutex_lock(&links_list_lock);
+	guard(mutex)(&links_list_lock);
 
 	link = find_link(dev);
 	if (!link) {
 		dev_err(&dev->dev, "actag information not found\n");
-		mutex_unlock(&links_list_lock);
 		return -ENODEV;
 	}
 	/*
@@ -274,7 +271,6 @@ int pnv_ocxl_get_actag(struct pci_dev *dev, u16 *base, u16 *enabled,
 	*enabled   = link->fn_actags[PCI_FUNC(dev->devfn)].count;
 	*supported = link->fn_desired_actags[PCI_FUNC(dev->devfn)];
 
-	mutex_unlock(&links_list_lock);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pnv_ocxl_get_actag);
@@ -293,12 +289,11 @@ int pnv_ocxl_get_pasid_count(struct pci_dev *dev, int *count)
 	 *
 	 * We only support one AFU-carrying function for now.
 	 */
-	mutex_lock(&links_list_lock);
+	guard(mutex)(&links_list_lock);
 
 	link = find_link(dev);
 	if (!link) {
 		dev_err(&dev->dev, "actag information not found\n");
-		mutex_unlock(&links_list_lock);
 		return -ENODEV;
 	}
 
@@ -309,7 +304,6 @@ int pnv_ocxl_get_pasid_count(struct pci_dev *dev, int *count)
 			break;
 		}
 
-	mutex_unlock(&links_list_lock);
 	dev_dbg(&dev->dev, "%d PASIDs available for function\n",
 		rc ? 0 : *count);
 	return rc;
-- 
2.39.3