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/drivers/perf/arm_brbe.h b/drivers/perf/arm_brbe.h
new file mode 100644
index 000000000..b7c7d8796
--- /dev/null
+++ b/drivers/perf/arm_brbe.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Branch Record Buffer Extension Helpers.
+ *
+ * Copyright (C) 2022-2025 ARM Limited
+ *
+ * Author: Anshuman Khandual <anshuman.khandual@arm.com>
+ */
+
+struct arm_pmu;
+struct perf_branch_stack;
+struct perf_event;
+
+#ifdef CONFIG_ARM64_BRBE
+void brbe_probe(struct arm_pmu *arm_pmu);
+unsigned int brbe_num_branch_records(const struct arm_pmu *armpmu);
+void brbe_invalidate(void);
+
+void brbe_enable(const struct arm_pmu *arm_pmu);
+void brbe_disable(void);
+
+bool brbe_branch_attr_valid(struct perf_event *event);
+void brbe_read_filtered_entries(struct perf_branch_stack *branch_stack,
+				const struct perf_event *event);
+#else
+static inline void brbe_probe(struct arm_pmu *arm_pmu) { }
+static inline unsigned int brbe_num_branch_records(const struct arm_pmu *armpmu)
+{
+	return 0;
+}
+
+static inline void brbe_invalidate(void) { }
+
+static inline void brbe_enable(const struct arm_pmu *arm_pmu) { };
+static inline void brbe_disable(void) { };
+
+static inline bool brbe_branch_attr_valid(struct perf_event *event)
+{
+	WARN_ON_ONCE(!has_branch_stack(event));
+	return false;
+}
+
+static void brbe_read_filtered_entries(struct perf_branch_stack *branch_stack,
+				       const struct perf_event *event)
+{
+}
+#endif