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, 51 insertions, 0 deletions

diff --git a/arch/alpha/lib/ev67-strlen.S b/arch/alpha/lib/ev67-strlen.S
new file mode 100644
index 000000000..3d9078807
--- /dev/null
+++ b/arch/alpha/lib/ev67-strlen.S
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/alpha/lib/ev67-strlen.S
+ * 21264 version by Rick Gorton <rick.gorton@alpha-processor.com>
+ *
+ * Finds length of a 0-terminated string.  Optimized for the
+ * Alpha architecture:
+ *
+ *	- memory accessed as aligned quadwords only
+ *	- uses bcmpge to compare 8 bytes in parallel
+ *
+ * Much of the information about 21264 scheduling/coding comes from:
+ *	Compiler Writer's Guide for the Alpha 21264
+ *	abbreviated as 'CWG' in other comments here
+ *	ftp.digital.com/pub/Digital/info/semiconductor/literature/dsc-library.html
+ * Scheduling notation:
+ *	E	- either cluster
+ *	U	- upper subcluster; U0 - subcluster U0; U1 - subcluster U1
+ *	L	- lower subcluster; L0 - subcluster L0; L1 - subcluster L1
+ */
+#include <linux/export.h>
+	.set noreorder
+	.set noat
+
+	.globl	strlen
+	.ent	strlen
+	.align 4
+strlen:
+	ldq_u	$1, 0($16)	# L : load first quadword ($16  may be misaligned)
+	lda	$2, -1($31)	# E :
+	insqh	$2, $16, $2	# U :
+	andnot	$16, 7, $0	# E :
+
+	or	$2, $1, $1	# E :
+	cmpbge	$31, $1, $2	# E : $2  <- bitmask: bit i == 1 <==> i-th byte == 0
+	nop			# E :
+	bne	$2, $found	# U :
+
+$loop:	ldq	$1, 8($0)	# L :
+	addq	$0, 8, $0	# E : addr += 8
+	cmpbge	$31, $1, $2	# E :
+	beq	$2, $loop	# U :
+
+$found:
+	cttz	$2, $3		# U0 :
+	addq	$0, $3, $0	# E :
+	subq	$0, $16, $0	# E :
+	ret	$31, ($26)	# L0 :
+
+	.end	strlen
+	EXPORT_SYMBOL(strlen)