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, 97 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-mce b/Documentation/ABI/testing/sysfs-mce
new file mode 100644
index 000000000..83172f50e
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-mce
@@ -0,0 +1,97 @@
+What:		/sys/devices/system/machinecheck/machinecheckX/
+Contact:	Andi Kleen <ak@linux.intel.com>
+Date:		Feb, 2007
+Description:
+		(X = CPU number)
+
+		Machine checks report internal hardware error conditions
+		detected by the CPU. Uncorrected errors typically cause a
+		machine check (often with panic), corrected ones cause a
+		machine check log entry.
+
+		For more details about the x86 machine check architecture
+		see the Intel and AMD architecture manuals from their
+		developer websites.
+
+		For more details about the architecture
+		see http://one.firstfloor.org/~andi/mce.pdf
+
+		Each CPU has its own directory.
+
+What:		/sys/devices/system/machinecheck/machinecheckX/bank<Y>
+Contact:	Andi Kleen <ak@linux.intel.com>
+Date:		Feb, 2007
+Description:
+		(Y bank number)
+
+		64bit Hex bitmask enabling/disabling specific subevents for
+		bank Y.
+
+		When a bit in the bitmask is zero then the respective
+		subevent will not be reported.
+
+		By default all events are enabled.
+
+		Note that BIOS maintain another mask to disable specific events
+		per bank.  This is not visible here
+
+What:		/sys/devices/system/machinecheck/machinecheckX/check_interval
+Contact:	Andi Kleen <ak@linux.intel.com>
+Date:		Feb, 2007
+Description:
+		The entries appear for each CPU, but they are truly shared
+		between all CPUs.
+
+		How often to poll for corrected machine check errors, in
+		seconds (Note output is hexadecimal). Default 5 minutes.
+		When the poller finds MCEs it triggers an exponential speedup
+		(poll more often) on the polling interval.  When the poller
+		stops finding MCEs, it triggers an exponential backoff
+		(poll less often) on the polling interval. The check_interval
+		variable is both the initial and maximum polling interval.
+		0 means no polling for corrected machine check errors
+		(but some corrected errors might be still reported
+		in other ways)
+
+What:		/sys/devices/system/machinecheck/machinecheckX/trigger
+Contact:	Andi Kleen <ak@linux.intel.com>
+Date:		Feb, 2007
+Description:
+		The entries appear for each CPU, but they are truly shared
+		between all CPUs.
+
+		Program to run when a machine check event is detected.
+		This is an alternative to running mcelog regularly from cron
+		and allows to detect events faster.
+
+What:		/sys/devices/system/machinecheck/machinecheckX/monarch_timeout
+Contact:	Andi Kleen <ak@linux.intel.com>
+Date:		Feb, 2007
+Description:
+		How long to wait for the other CPUs to machine check too on a
+		exception. 0 to disable waiting for other CPUs.
+
+		Unit: us
+
+What:		/sys/devices/system/machinecheck/machinecheckX/ignore_ce
+Contact:	Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
+Date:		Jun 2009
+Description:
+		Disables polling and CMCI for corrected errors.
+		All corrected events are not cleared and kept in bank MSRs.
+
+What:		/sys/devices/system/machinecheck/machinecheckX/dont_log_ce
+Contact:	Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
+Date:		Jun 2009
+Description:
+		Disables logging for corrected errors.
+		All reported corrected errors will be cleared silently.
+
+		This option will be useful if you never care about corrected
+		errors.
+
+What:		/sys/devices/system/machinecheck/machinecheckX/cmci_disabled
+Contact:	Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
+Date:		Jun 2009
+Description:
+		Disables the CMCI feature.