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, 10 insertions, 0 deletions

diff --git a/include/asm-generic/string.h b/include/asm-generic/string.h
new file mode 100644
index 000000000..de5e02014
--- /dev/null
+++ b/include/asm-generic/string.h
@@ -0,0 +1,10 @@
+#ifndef __ASM_GENERIC_STRING_H
+#define __ASM_GENERIC_STRING_H
+/*
+ * The kernel provides all required functions in lib/string.c
+ *
+ * Architectures probably want to provide at least their own optimized
+ * memcpy and memset functions though.
+ */
+
+#endif /* __ASM_GENERIC_STRING_H */