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, 63 insertions, 0 deletions

diff --git a/net/ceph/snapshot.c b/net/ceph/snapshot.c
new file mode 100644
index 000000000..e24315937
--- /dev/null
+++ b/net/ceph/snapshot.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * snapshot.c    Ceph snapshot context utility routines (part of libceph)
+ *
+ * Copyright (C) 2013 Inktank Storage, Inc.
+ */
+
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/ceph/libceph.h>
+
+/*
+ * Ceph snapshot contexts are reference counted objects, and the
+ * returned structure holds a single reference.  Acquire additional
+ * references with ceph_get_snap_context(), and release them with
+ * ceph_put_snap_context().  When the reference count reaches zero
+ * the entire structure is freed.
+ */
+
+/*
+ * Create a new ceph snapshot context large enough to hold the
+ * indicated number of snapshot ids (which can be 0).  Caller has
+ * to fill in snapc->seq and snapc->snaps[0..snap_count-1].
+ *
+ * Returns a null pointer if an error occurs.
+ */
+struct ceph_snap_context *ceph_create_snap_context(u32 snap_count,
+						gfp_t gfp_flags)
+{
+	struct ceph_snap_context *snapc;
+	size_t size;
+
+	size = sizeof (struct ceph_snap_context);
+	size += snap_count * sizeof (snapc->snaps[0]);
+	snapc = kzalloc(size, gfp_flags);
+	if (!snapc)
+		return NULL;
+
+	refcount_set(&snapc->nref, 1);
+	snapc->num_snaps = snap_count;
+
+	return snapc;
+}
+EXPORT_SYMBOL(ceph_create_snap_context);
+
+struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc)
+{
+	if (sc)
+		refcount_inc(&sc->nref);
+	return sc;
+}
+EXPORT_SYMBOL(ceph_get_snap_context);
+
+void ceph_put_snap_context(struct ceph_snap_context *sc)
+{
+	if (!sc)
+		return;
+	if (refcount_dec_and_test(&sc->nref)) {
+		/*printk(" deleting snap_context %p\n", sc);*/
+		kfree(sc);
+	}
+}
+EXPORT_SYMBOL(ceph_put_snap_context);