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/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
new file mode 100644
index 000000000..892e69ab4
--- /dev/null
+++ b/init/do_mounts_initrd.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/unistd.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/initrd.h>
+
+#include "do_mounts.h"
+
+unsigned long initrd_start, initrd_end;
+int initrd_below_start_ok;
+static int __initdata mount_initrd = 1;
+
+phys_addr_t phys_initrd_start __initdata;
+unsigned long phys_initrd_size __initdata;
+
+static int __init no_initrd(char *str)
+{
+	pr_warn("noinitrd option is deprecated and will be removed soon\n");
+	mount_initrd = 0;
+	return 1;
+}
+
+__setup("noinitrd", no_initrd);
+
+static int __init early_initrdmem(char *p)
+{
+	phys_addr_t start;
+	unsigned long size;
+	char *endp;
+
+	start = memparse(p, &endp);
+	if (*endp == ',') {
+		size = memparse(endp + 1, NULL);
+
+		phys_initrd_start = start;
+		phys_initrd_size = size;
+	}
+	return 0;
+}
+early_param("initrdmem", early_initrdmem);
+
+static int __init early_initrd(char *p)
+{
+	return early_initrdmem(p);
+}
+early_param("initrd", early_initrd);
+
+void __init initrd_load(void)
+{
+	if (mount_initrd) {
+		create_dev("/dev/ram", Root_RAM0);
+		/*
+		 * Load the initrd data into /dev/ram0.
+		 */
+		if (rd_load_image()) {
+			pr_warn("using deprecated initrd support, will be removed in January 2027; "
+				"use initramfs instead or (as a last resort) /sys/firmware/initrd; "
+				"see section \"Workaround\" in "
+				"https://lore.kernel.org/lkml/20251010094047.3111495-1-safinaskar@gmail.com\n");
+		}
+	}
+	init_unlink("/initrd.image");
+}