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, 43 insertions, 0 deletions

diff --git a/Documentation/admin-guide/device-mapper/index.rst b/Documentation/admin-guide/device-mapper/index.rst
new file mode 100644
index 000000000..73c1f2002
--- /dev/null
+++ b/Documentation/admin-guide/device-mapper/index.rst
@@ -0,0 +1,43 @@
+=============
+Device Mapper
+=============
+
+.. toctree::
+    :maxdepth: 1
+
+    cache-policies
+    cache
+    delay
+    dm-clone
+    dm-crypt
+    dm-dust
+    dm-ebs
+    dm-flakey
+    dm-ima
+    dm-init
+    dm-inlinecrypt
+    dm-integrity
+    dm-io
+    dm-log
+    dm-pcache
+    dm-queue-length
+    dm-raid
+    dm-service-time
+    dm-uevent
+    dm-zoned
+    era
+    kcopyd
+    linear
+    log-writes
+    persistent-data
+    snapshot
+    statistics
+    striped
+    switch
+    thin-provisioning
+    unstriped
+    vdo-design
+    vdo
+    verity
+    writecache
+    zero