PCI/MSI: Switch msix_capability_init() to guard(msi_desc_lock)

Split the lock protected functionality of msix_capability_init() out into a
helper function and use guard(msi_desc_lock) to replace the lock/unlock
pair.

Simplify the error path in the helper function by utilizing a custom
cleanup to get rid of the remaining gotos.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/all/20250319105506.564105011@linutronix.de

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 99874839cc7b98f093746f48eaf76edcf7a5a21b..732166a9192c145a4ae474395e1bb6e0a2908e0a 100644 (file)
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -660,35 +660,39 @@ static void msix_mask_all(void __iomem *base, int tsize)
                writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL);
 }
 
-static int msix_setup_interrupts(struct pci_dev *dev, struct msix_entry *entries,
-                                int nvec, struct irq_affinity *affd)
+DEFINE_FREE(free_msi_irqs, struct pci_dev *, if (_T) pci_free_msi_irqs(_T));
+
+static int __msix_setup_interrupts(struct pci_dev *__dev, struct msix_entry *entries,
+                                  int nvec, struct irq_affinity_desc *masks)
 {
-       struct irq_affinity_desc *masks __free(kfree) =
-               affd ? irq_create_affinity_masks(nvec, affd) : NULL;
-       int ret;
+       struct pci_dev *dev __free(free_msi_irqs) = __dev;
 
-       msi_lock_descs(&dev->dev);
-       ret = msix_setup_msi_descs(dev, entries, nvec, masks);
+       int ret = msix_setup_msi_descs(dev, entries, nvec, masks);
        if (ret)
-               goto out_free;
+               return ret;
 
        ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
        if (ret)
-               goto out_free;
+               return ret;
 
        /* Check if all MSI entries honor device restrictions */
        ret = msi_verify_entries(dev);
        if (ret)
-               goto out_free;
+               return ret;
 
        msix_update_entries(dev, entries);
-       goto out_unlock;
+       retain_and_null_ptr(dev);
+       return 0;
+}
 
-out_free:
-       pci_free_msi_irqs(dev);
-out_unlock:
-       msi_unlock_descs(&dev->dev);
-       return ret;
+static int msix_setup_interrupts(struct pci_dev *dev, struct msix_entry *entries,
+                                int nvec, struct irq_affinity *affd)
+{
+       struct irq_affinity_desc *masks __free(kfree) =
+               affd ? irq_create_affinity_masks(nvec, affd) : NULL;
+
+       guard(msi_descs_lock)(&dev->dev);
+       return __msix_setup_interrupts(dev, entries, nvec, masks);
 }
 
 /**