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, 47 insertions, 0 deletions

diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
new file mode 100644
index 000000000..27f11320b
--- /dev/null
+++ b/block/Kconfig.iosched
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0
+menu "IO Schedulers"
+
+config MQ_IOSCHED_DEADLINE
+	tristate "MQ deadline I/O scheduler"
+	default y
+	help
+	  MQ version of the deadline IO scheduler.
+
+config MQ_IOSCHED_KYBER
+	tristate "Kyber I/O scheduler"
+	default y
+	help
+	  The Kyber I/O scheduler is a low-overhead scheduler suitable for
+	  multiqueue and other fast devices. Given target latencies for reads and
+	  synchronous writes, it will self-tune queue depths to achieve that
+	  goal.
+
+config IOSCHED_BFQ
+	tristate "BFQ I/O scheduler"
+	select BLK_ICQ
+	help
+	BFQ I/O scheduler for BLK-MQ. BFQ distributes the bandwidth of
+	of the device among all processes according to their weights,
+	regardless of the device parameters and with any workload. It
+	also guarantees a low latency to interactive and soft
+	real-time applications.  Details in
+	Documentation/block/bfq-iosched.rst
+
+config BFQ_GROUP_IOSCHED
+       bool "BFQ hierarchical scheduling support"
+       depends on IOSCHED_BFQ && BLK_CGROUP
+       default y
+       select BLK_CGROUP_RWSTAT
+	help
+
+       Enable hierarchical scheduling in BFQ, using the blkio
+       (cgroups-v1) or io (cgroups-v2) controller.
+
+config BFQ_CGROUP_DEBUG
+	bool "BFQ IO controller debugging"
+	depends on BFQ_GROUP_IOSCHED
+	help
+	Enable some debugging help. Currently it exports additional stat
+	files in a cgroup which can be useful for debugging.
+
+endmenu