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, 61 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-ksm b/Documentation/ABI/testing/sysfs-kernel-mm-ksm
new file mode 100644
index 000000000..6041a025b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-ksm
@@ -0,0 +1,61 @@
+What:		/sys/kernel/mm/ksm
+Date:		September 2009
+KernelVersion:	2.6.32
+Contact:	Linux memory management mailing list <linux-mm@kvack.org>
+Description:	Interface for Kernel Samepage Merging (KSM)
+
+What:		/sys/kernel/mm/ksm/full_scans
+What:		/sys/kernel/mm/ksm/pages_shared
+What:		/sys/kernel/mm/ksm/pages_sharing
+What:		/sys/kernel/mm/ksm/pages_to_scan
+What:		/sys/kernel/mm/ksm/pages_unshared
+What:		/sys/kernel/mm/ksm/pages_volatile
+What:		/sys/kernel/mm/ksm/run
+What:		/sys/kernel/mm/ksm/sleep_millisecs
+Date:		September 2009
+Contact:	Linux memory management mailing list <linux-mm@kvack.org>
+Description:	Kernel Samepage Merging daemon sysfs interface
+
+		full_scans: how many times all mergeable areas have been
+		scanned.
+
+		pages_shared: how many shared pages are being used.
+
+		pages_sharing: how many more sites are sharing them i.e. how
+		much saved.
+
+		pages_to_scan: how many present pages to scan before ksmd goes
+		to sleep.
+
+		pages_unshared: how many pages unique but repeatedly checked
+		for merging.
+
+		pages_volatile: how many pages changing too fast to be placed
+		in a tree.
+
+		run: write 0 to disable ksm, read 0 while ksm is disabled.
+
+			- write 1 to run ksm, read 1 while ksm is running.
+			- write 2 to disable ksm and unmerge all its pages.
+
+		sleep_millisecs: how many milliseconds ksm should sleep between
+		scans.
+
+		See Documentation/mm/ksm.rst for more information.
+
+What:		/sys/kernel/mm/ksm/merge_across_nodes
+Date:		January 2013
+KernelVersion:	3.9
+Contact:	Linux memory management mailing list <linux-mm@kvack.org>
+Description:	Control merging pages across different NUMA nodes.
+
+		When it is set to 0 only pages from the same node are merged,
+		otherwise pages from all nodes can be merged together (default).
+
+What:		/sys/kernel/mm/ksm/general_profit
+Date:		April 2023
+KernelVersion:  6.4
+Contact:	Linux memory management mailing list <linux-mm@kvack.org>
+Description:	Measure how effective KSM is.
+		general_profit: how effective is KSM. The formula for the
+		calculation is in Documentation/admin-guide/mm/ksm.rst.