powerpc: powernv: ocxl: use lock guard for mutex

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>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250505075333.184463-6-sshegde@linux.ibm.com

diff --git a/arch/powerpc/platforms/powernv/ocxl.c b/arch/powerpc/platforms/powernv/ocxl.c
index 64a9c7125c2942a27c0a83b91fc02790ca2c7cda..f8139948348e8b75523a792d312c3b85418017c8 100644 (file)
--- 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;