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, 114 insertions, 0 deletions

diff --git a/Documentation/process/index.rst b/Documentation/process/index.rst
new file mode 100644
index 000000000..aa7c959a5
--- /dev/null
+++ b/Documentation/process/index.rst
@@ -0,0 +1,114 @@
+.. raw:: latex
+
+	\renewcommand\thesection*
+	\renewcommand\thesubsection*
+
+.. _process_index:
+
+=============================================
+Working with the kernel development community
+=============================================
+
+So you want to be a Linux kernel developer?  Welcome!  While there is a lot
+to be learned about the kernel in a technical sense, it is also important
+to learn about how our community works.  Reading these documents will make
+it much easier for you to get your changes merged with a minimum of
+trouble.
+
+An introduction to how kernel development works
+-----------------------------------------------
+
+Read these documents first: an understanding of the material here will ease
+your entry into the kernel community.
+
+.. toctree::
+   :maxdepth: 1
+
+   howto
+   development-process
+   submitting-patches
+   submit-checklist
+
+Tools and technical guides for kernel developers
+------------------------------------------------
+
+This is a collection of material that kernel developers should be familiar
+with.
+
+.. toctree::
+   :maxdepth: 1
+
+   changes
+   programming-language
+   coding-style
+   maintainer-pgp-guide
+   email-clients
+   applying-patches
+   backporting
+   adding-syscalls
+   volatile-considered-harmful
+   botching-up-ioctls
+
+Policy guides and developer statements
+--------------------------------------
+
+These are the rules that we try to live by in the kernel community (and
+beyond).
+
+.. toctree::
+   :maxdepth: 1
+
+   license-rules
+   code-of-conduct
+   code-of-conduct-interpretation
+   contribution-maturity-model
+   kernel-enforcement-statement
+   kernel-driver-statement
+   stable-api-nonsense
+   stable-kernel-rules
+   management-style
+   researcher-guidelines
+   generated-content
+   coding-assistants
+   conclave
+
+Dealing with bugs
+-----------------
+
+Bugs are a fact of life; it is important that we handle them properly. The
+documents below provide general advice about debugging and describe our
+policies around the handling of a couple of special classes of bugs:
+regressions and security problems.
+
+.. toctree::
+   :maxdepth: 1
+
+   debugging/index
+   handling-regressions
+   security-bugs
+   threat-model
+   cve
+   embargoed-hardware-issues
+
+Maintainer information
+----------------------
+
+How to find the people who will accept your patches.
+
+.. toctree::
+   :maxdepth: 1
+
+   maintainer-handbooks
+   maintainers
+
+Other material
+--------------
+
+Here are some other guides to the community that are of interest to most
+developers:
+
+.. toctree::
+   :maxdepth: 1
+
+   kernel-docs
+   deprecated