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/net/dsa/trace.c b/net/dsa/trace.c
new file mode 100644
index 000000000..1b107165d
--- /dev/null
+++ b/net/dsa/trace.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Copyright 2022-2023 NXP
+ */
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
+void dsa_db_print(const struct dsa_db *db, char buf[DSA_DB_BUFSIZ])
+{
+	switch (db->type) {
+	case DSA_DB_PORT:
+		sprintf(buf, "port %s", db->dp->name);
+		break;
+	case DSA_DB_LAG:
+		sprintf(buf, "lag %s id %d", db->lag.dev->name, db->lag.id);
+		break;
+	case DSA_DB_BRIDGE:
+		sprintf(buf, "bridge %s num %d", db->bridge.dev->name,
+			db->bridge.num);
+		break;
+	default:
+		sprintf(buf, "unknown");
+		break;
+	}
+}
+
+const char *dsa_port_kind(const struct dsa_port *dp)
+{
+	switch (dp->type) {
+	case DSA_PORT_TYPE_USER:
+		return "user";
+	case DSA_PORT_TYPE_CPU:
+		return "cpu";
+	case DSA_PORT_TYPE_DSA:
+		return "dsa";
+	default:
+		return "unused";
+	}
+}