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, 99 insertions, 0 deletions

diff --git a/net/sched/em_cmp.c b/net/sched/em_cmp.c
new file mode 100644
index 000000000..48c1bce74
--- /dev/null
+++ b/net/sched/em_cmp.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/sched/em_cmp.c	Simple packet data comparison ematch
+ *
+ * Authors:	Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/tc_ematch/tc_em_cmp.h>
+#include <linux/unaligned.h>
+#include <net/pkt_cls.h>
+
+static inline int cmp_needs_transformation(struct tcf_em_cmp *cmp)
+{
+	return unlikely(cmp->flags & TCF_EM_CMP_TRANS);
+}
+
+static int em_cmp_match(struct sk_buff *skb, struct tcf_ematch *em,
+			struct tcf_pkt_info *info)
+{
+	struct tcf_em_cmp *cmp = (struct tcf_em_cmp *) em->data;
+	unsigned char *ptr = tcf_get_base_ptr(skb, cmp->layer);
+	u32 val = 0;
+
+	if (!ptr)
+		return 0;
+	ptr += cmp->off;
+	if (!tcf_valid_offset(skb, ptr, cmp->align))
+		return 0;
+
+	switch (cmp->align) {
+	case TCF_EM_ALIGN_U8:
+		val = *ptr;
+		break;
+
+	case TCF_EM_ALIGN_U16:
+		val = get_unaligned_be16(ptr);
+
+		if (cmp_needs_transformation(cmp))
+			val = be16_to_cpu(val);
+		break;
+
+	case TCF_EM_ALIGN_U32:
+		/* Worth checking boundaries? The branching seems
+		 * to get worse. Visit again.
+		 */
+		val = get_unaligned_be32(ptr);
+
+		if (cmp_needs_transformation(cmp))
+			val = be32_to_cpu(val);
+		break;
+
+	default:
+		return 0;
+	}
+
+	if (cmp->mask)
+		val &= cmp->mask;
+
+	switch (cmp->opnd) {
+	case TCF_EM_OPND_EQ:
+		return val == cmp->val;
+	case TCF_EM_OPND_LT:
+		return val < cmp->val;
+	case TCF_EM_OPND_GT:
+		return val > cmp->val;
+	}
+
+	return 0;
+}
+
+static struct tcf_ematch_ops em_cmp_ops = {
+	.kind	  = TCF_EM_CMP,
+	.datalen  = sizeof(struct tcf_em_cmp),
+	.match	  = em_cmp_match,
+	.owner	  = THIS_MODULE,
+	.link	  = LIST_HEAD_INIT(em_cmp_ops.link)
+};
+
+static int __init init_em_cmp(void)
+{
+	return tcf_em_register(&em_cmp_ops);
+}
+
+static void __exit exit_em_cmp(void)
+{
+	tcf_em_unregister(&em_cmp_ops);
+}
+
+MODULE_DESCRIPTION("ematch classifier for basic data types(8/16/32 bit) against skb data");
+MODULE_LICENSE("GPL");
+
+module_init(init_em_cmp);
+module_exit(exit_em_cmp);
+
+MODULE_ALIAS_TCF_EMATCH(TCF_EM_CMP);