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, 37 insertions, 0 deletions

diff --git a/include/uapi/asm-generic/ipcbuf.h b/include/uapi/asm-generic/ipcbuf.h
new file mode 100644
index 000000000..41a01b494
--- /dev/null
+++ b/include/uapi/asm-generic/ipcbuf.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __ASM_GENERIC_IPCBUF_H
+#define __ASM_GENERIC_IPCBUF_H
+
+#include <linux/posix_types.h>
+
+/*
+ * The generic ipc64_perm structure:
+ * Note extra padding because this structure is passed back and forth
+ * between kernel and user space.
+ *
+ * ipc64_perm was originally meant to be architecture specific, but
+ * everyone just ended up making identical copies without specific
+ * optimizations, so we may just as well all use the same one.
+ *
+ * Pad space is left for:
+ * - 32-bit mode_t on architectures that only had 16 bit
+ * - 32-bit seq
+ * - 2 miscellaneous 32-bit values
+ */
+
+struct ipc64_perm {
+	__kernel_key_t		key;
+	__kernel_uid32_t	uid;
+	__kernel_gid32_t	gid;
+	__kernel_uid32_t	cuid;
+	__kernel_gid32_t	cgid;
+	__kernel_mode_t		mode;
+				/* pad if mode_t is u16: */
+	unsigned char		__pad1[4 - sizeof(__kernel_mode_t)];
+	unsigned short		seq;
+	unsigned short		__pad2;
+	__kernel_ulong_t	__unused1;
+	__kernel_ulong_t	__unused2;
+};
+
+#endif /* __ASM_GENERIC_IPCBUF_H */