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, 112 insertions, 0 deletions

diff --git a/rust/quote/ext.rs b/rust/quote/ext.rs
new file mode 100644
index 000000000..977d2f0c5
--- /dev/null
+++ b/rust/quote/ext.rs
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use super::ToTokens;
+use core::iter;
+use proc_macro2::{TokenStream, TokenTree};
+
+/// TokenStream extension trait with methods for appending tokens.
+///
+/// This trait is sealed and cannot be implemented outside of the `quote` crate.
+pub trait TokenStreamExt: private::Sealed {
+    /// For use by `ToTokens` implementations.
+    ///
+    /// Appends the token specified to this list of tokens.
+    fn append<U>(&mut self, token: U)
+    where
+        U: Into<TokenTree>;
+
+    /// For use by `ToTokens` implementations.
+    ///
+    /// ```
+    /// # use quote::{quote, TokenStreamExt, ToTokens};
+    /// # use proc_macro2::TokenStream;
+    /// #
+    /// struct X;
+    ///
+    /// impl ToTokens for X {
+    ///     fn to_tokens(&self, tokens: &mut TokenStream) {
+    ///         tokens.append_all(&[true, false]);
+    ///     }
+    /// }
+    ///
+    /// let tokens = quote!(#X);
+    /// assert_eq!(tokens.to_string(), "true false");
+    /// ```
+    fn append_all<I>(&mut self, iter: I)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens;
+
+    /// For use by `ToTokens` implementations.
+    ///
+    /// Appends all of the items in the iterator `I`, separated by the tokens
+    /// `U`.
+    fn append_separated<I, U>(&mut self, iter: I, op: U)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+        U: ToTokens;
+
+    /// For use by `ToTokens` implementations.
+    ///
+    /// Appends all tokens in the iterator `I`, appending `U` after each
+    /// element, including after the last element of the iterator.
+    fn append_terminated<I, U>(&mut self, iter: I, term: U)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+        U: ToTokens;
+}
+
+impl TokenStreamExt for TokenStream {
+    fn append<U>(&mut self, token: U)
+    where
+        U: Into<TokenTree>,
+    {
+        self.extend(iter::once(token.into()));
+    }
+
+    fn append_all<I>(&mut self, iter: I)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+    {
+        for token in iter {
+            token.to_tokens(self);
+        }
+    }
+
+    fn append_separated<I, U>(&mut self, iter: I, op: U)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+        U: ToTokens,
+    {
+        for (i, token) in iter.into_iter().enumerate() {
+            if i > 0 {
+                op.to_tokens(self);
+            }
+            token.to_tokens(self);
+        }
+    }
+
+    fn append_terminated<I, U>(&mut self, iter: I, term: U)
+    where
+        I: IntoIterator,
+        I::Item: ToTokens,
+        U: ToTokens,
+    {
+        for token in iter {
+            token.to_tokens(self);
+            term.to_tokens(self);
+        }
+    }
+}
+
+mod private {
+    use proc_macro2::TokenStream;
+
+    pub trait Sealed {}
+
+    impl Sealed for TokenStream {}
+}