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

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

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/20250319105506.504992208@linutronix.de

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 85c2aba93f18c108a795c59b347c24eefd11a46d..99874839cc7b98f093746f48eaf76edcf7a5a21b 100644 (file)
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -335,38 +335,13 @@ static int msi_verify_entries(struct pci_dev *dev)
        return !entry ? 0 : -EIO;
 }
 
-/**
- * msi_capability_init - configure device's MSI capability structure
- * @dev: pointer to the pci_dev data structure of MSI device function
- * @nvec: number of interrupts to allocate
- * @affd: description of automatic IRQ affinity assignments (may be %NULL)
- *
- * Setup the MSI capability structure of the device with the requested
- * number of interrupts.  A return value of zero indicates the successful
- * setup of an entry with the new MSI IRQ.  A negative return value indicates
- * an error, and a positive return value indicates the number of interrupts
- * which could have been allocated.
- */
-static int msi_capability_init(struct pci_dev *dev, int nvec,
-                              struct irq_affinity *affd)
+static int __msi_capability_init(struct pci_dev *dev, int nvec, struct irq_affinity_desc *masks)
 {
+       int ret = msi_setup_msi_desc(dev, nvec, masks);
        struct msi_desc *entry, desc;
-       int ret;
 
-       /* Reject multi-MSI early on irq domain enabled architectures */
-       if (nvec > 1 && !pci_msi_domain_supports(dev, MSI_FLAG_MULTI_PCI_MSI, ALLOW_LEGACY))
-               return 1;
-
-       /* Disable MSI during setup in the hardware to erase stale state */
-       pci_msi_set_enable(dev, 0);
-
-       struct irq_affinity_desc *masks __free(kfree) =
-               affd ? irq_create_affinity_masks(nvec, affd) : NULL;
-
-       msi_lock_descs(&dev->dev);
-       ret = msi_setup_msi_desc(dev, nvec, masks);
        if (ret)
-               goto unlock;
+               return ret;
 
        /* All MSIs are unmasked by default; mask them all */
        entry = msi_first_desc(&dev->dev, MSI_DESC_ALL);
@@ -394,16 +369,45 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
 
        pcibios_free_irq(dev);
        dev->irq = entry->irq;
-       goto unlock;
-
+       return 0;
 err:
        pci_msi_unmask(&desc, msi_multi_mask(&desc));
        pci_free_msi_irqs(dev);
-unlock:
-       msi_unlock_descs(&dev->dev);
        return ret;
 }
 
+/**
+ * msi_capability_init - configure device's MSI capability structure
+ * @dev: pointer to the pci_dev data structure of MSI device function
+ * @nvec: number of interrupts to allocate
+ * @affd: description of automatic IRQ affinity assignments (may be %NULL)
+ *
+ * Setup the MSI capability structure of the device with the requested
+ * number of interrupts.  A return value of zero indicates the successful
+ * setup of an entry with the new MSI IRQ.  A negative return value indicates
+ * an error, and a positive return value indicates the number of interrupts
+ * which could have been allocated.
+ */
+static int msi_capability_init(struct pci_dev *dev, int nvec,
+                              struct irq_affinity *affd)
+{
+       /* Reject multi-MSI early on irq domain enabled architectures */
+       if (nvec > 1 && !pci_msi_domain_supports(dev, MSI_FLAG_MULTI_PCI_MSI, ALLOW_LEGACY))
+               return 1;
+
+       /*
+        * Disable MSI during setup in the hardware, but mark it enabled
+        * so that setup code can evaluate it.
+        */
+       pci_msi_set_enable(dev, 0);
+
+       struct irq_affinity_desc *masks __free(kfree) =
+               affd ? irq_create_affinity_masks(nvec, affd) : NULL;
+
+       guard(msi_descs_lock)(&dev->dev);
+       return __msi_capability_init(dev, nvec, masks);
+}
+
 int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
                           struct irq_affinity *affd)
 {