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, 36 insertions, 0 deletions

diff --git a/include/uapi/fwctl/mlx5.h b/include/uapi/fwctl/mlx5.h
new file mode 100644
index 000000000..625819180
--- /dev/null
+++ b/include/uapi/fwctl/mlx5.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2024-2025, NVIDIA CORPORATION & AFFILIATES
+ *
+ * These are definitions for the command interface for mlx5 HW. mlx5 FW has a
+ * User Context mechanism which allows the FW to understand a security scope.
+ * FWCTL binds each FD to a FW user context and then places the User Context ID
+ * (UID) in each command header. The created User Context has a capability set
+ * that is appropriate for FWCTL's security model.
+ *
+ * Command formation should use a copy of the structs in mlx5_ifc.h following
+ * the Programmers Reference Manual. A open release is available here:
+ *
+ *  https://network.nvidia.com/files/doc-2020/ethernet-adapters-programming-manual.pdf
+ *
+ * The device_type for this file is FWCTL_DEVICE_TYPE_MLX5.
+ */
+#ifndef _UAPI_FWCTL_MLX5_H
+#define _UAPI_FWCTL_MLX5_H
+
+#include <linux/types.h>
+
+/**
+ * struct fwctl_info_mlx5 - ioctl(FWCTL_INFO) out_device_data
+ * @uid: The FW UID this FD is bound to. Each command header will force
+ *	this value.
+ * @uctx_caps: The FW capabilities that are enabled for the uid.
+ *
+ * Return basic information about the FW interface available.
+ */
+struct fwctl_info_mlx5 {
+	__u32 uid;
+	__u32 uctx_caps;
+};
+
+#endif