PCI: Add pci_irq_type() to query the allocated interrupt typegrafted

Add a helper that returns PCI_IRQ_MSIX, PCI_IRQ_MSI, or PCI_IRQ_INTX
based on the interrupt type the PCI core selected after
pci_alloc_irq_vectors().

Several drivers already open-code this check against pdev->msix_enabled
and pdev->msi_enabled, or even open code this helper [1].

A common helper avoids the duplication and keeps drivers from accessing
the bitfield directly (see also [2]).

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Link: https://elixir.bootlin.com/linux/v7.1/source/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c#L196 [1]
Inspired-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/all/DKKG2QM3YJYB.Z2H2B2UXJ75N@kernel.org/ [2]
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260813165234.620555-5-dakr@kernel.org
[ Add missing pci_irq_type() stub for CONFIG_PCI=n. ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/include/net/dcbevent.h b/include/net/dcbevent.h
new file mode 100644
index 000000000..02700262f
--- /dev/null
+++ b/include/net/dcbevent.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2010, Intel Corporation.
+ *
+ * Author: John Fastabend <john.r.fastabend@intel.com>
+ */
+
+#ifndef _DCB_EVENT_H
+#define _DCB_EVENT_H
+
+struct notifier_block;
+
+enum dcbevent_notif_type {
+	DCB_APP_EVENT = 1,
+};
+
+#ifdef CONFIG_DCB
+int register_dcbevent_notifier(struct notifier_block *nb);
+int unregister_dcbevent_notifier(struct notifier_block *nb);
+int call_dcbevent_notifiers(unsigned long val, void *v);
+#else
+static inline int
+register_dcbevent_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
+
+static inline int unregister_dcbevent_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
+
+static inline int call_dcbevent_notifiers(unsigned long val, void *v)
+{
+	return 0;
+}
+#endif /* CONFIG_DCB */
+
+#endif