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, 143 insertions, 0 deletions

diff --git a/net/sunrpc/auth_null.c b/net/sunrpc/auth_null.c
new file mode 100644
index 000000000..41a633a40
--- /dev/null
+++ b/net/sunrpc/auth_null.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/net/sunrpc/auth_null.c
+ *
+ * AUTH_NULL authentication. Really :-)
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/sunrpc/clnt.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+static struct rpc_auth null_auth;
+static struct rpc_cred null_cred;
+
+static struct rpc_auth *
+nul_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
+{
+	refcount_inc(&null_auth.au_count);
+	return &null_auth;
+}
+
+static void
+nul_destroy(struct rpc_auth *auth)
+{
+}
+
+/*
+ * Lookup NULL creds for current process
+ */
+static struct rpc_cred *
+nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+{
+	return get_rpccred(&null_cred);
+}
+
+/*
+ * Destroy cred handle.
+ */
+static void
+nul_destroy_cred(struct rpc_cred *cred)
+{
+}
+
+/*
+ * Match cred handle against current process
+ */
+static int
+nul_match(struct auth_cred *acred, struct rpc_cred *cred, int taskflags)
+{
+	return 1;
+}
+
+/*
+ * Marshal credential.
+ */
+static int
+nul_marshal(struct rpc_task *task, struct xdr_stream *xdr)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 * sizeof(*p));
+	if (!p)
+		return -EMSGSIZE;
+	/* Credential */
+	*p++ = rpc_auth_null;
+	*p++ = xdr_zero;
+	/* Verifier */
+	*p++ = rpc_auth_null;
+	*p   = xdr_zero;
+	return 0;
+}
+
+/*
+ * Refresh credential. This is a no-op for AUTH_NULL
+ */
+static int
+nul_refresh(struct rpc_task *task)
+{
+	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
+	return 0;
+}
+
+static int
+nul_validate(struct rpc_task *task, struct xdr_stream *xdr)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 2 * sizeof(*p));
+	if (!p)
+		return -EIO;
+	if (*p++ != rpc_auth_null)
+		return -EIO;
+	if (*p != xdr_zero)
+		return -EIO;
+	return 0;
+}
+
+const struct rpc_authops authnull_ops = {
+	.owner		= THIS_MODULE,
+	.au_flavor	= RPC_AUTH_NULL,
+	.au_name	= "NULL",
+	.create		= nul_create,
+	.destroy	= nul_destroy,
+	.lookup_cred	= nul_lookup_cred,
+};
+
+static
+struct rpc_auth null_auth = {
+	.au_cslack	= NUL_CALLSLACK,
+	.au_rslack	= NUL_REPLYSLACK,
+	.au_verfsize	= NUL_REPLYSLACK,
+	.au_ralign	= NUL_REPLYSLACK,
+	.au_ops		= &authnull_ops,
+	.au_flavor	= RPC_AUTH_NULL,
+	.au_count	= REFCOUNT_INIT(1),
+};
+
+static
+const struct rpc_credops null_credops = {
+	.cr_name	= "AUTH_NULL",
+	.crdestroy	= nul_destroy_cred,
+	.crmatch	= nul_match,
+	.crmarshal	= nul_marshal,
+	.crwrap_req	= rpcauth_wrap_req_encode,
+	.crrefresh	= nul_refresh,
+	.crvalidate	= nul_validate,
+	.crunwrap_resp	= rpcauth_unwrap_resp_decode,
+};
+
+static
+struct rpc_cred null_cred = {
+	.cr_lru		= LIST_HEAD_INIT(null_cred.cr_lru),
+	.cr_auth	= &null_auth,
+	.cr_ops		= &null_credops,
+	.cr_count	= REFCOUNT_INIT(2),
+	.cr_flags	= 1UL << RPCAUTH_CRED_UPTODATE,
+};