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, 43 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/grackle.c b/arch/powerpc/sysdev/grackle.c
new file mode 100644
index 000000000..7dce8278b
--- /dev/null
+++ b/arch/powerpc/sysdev/grackle.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Functions for setting up and using a MPC106 northbridge
+ * Extracted from arch/powerpc/platforms/powermac/pci.c.
+ *
+ * Copyright (C) 2003 Benjamin Herrenschmuidt (benh@kernel.crashing.org)
+ * Copyright (C) 1997 Paul Mackerras (paulus@samba.org)
+ */
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/of.h>
+
+#include <asm/io.h>
+#include <asm/pci-bridge.h>
+#include <asm/grackle.h>
+
+#define GRACKLE_CFA(b, d, o)	(0x80 | ((b) << 8) | ((d) << 16) \
+				 | (((o) & ~3) << 24))
+
+#define GRACKLE_PICR1_LOOPSNOOP		0x00000010
+
+static inline void grackle_set_loop_snoop(struct pci_controller *bp, int enable)
+{
+	unsigned int val;
+
+	out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
+	val = in_le32(bp->cfg_data);
+	val = enable? (val | GRACKLE_PICR1_LOOPSNOOP) :
+		(val & ~GRACKLE_PICR1_LOOPSNOOP);
+	out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
+	out_le32(bp->cfg_data, val);
+	(void)in_le32(bp->cfg_data);
+}
+
+void __init setup_grackle(struct pci_controller *hose)
+{
+	setup_indirect_pci(hose, 0xfec00000, 0xfee00000, 0);
+	if (of_machine_is_compatible("PowerMac1,1"))
+		pci_add_flags(PCI_REASSIGN_ALL_BUS);
+	if (of_machine_is_compatible("AAPL,PowerBook1998"))
+		grackle_set_loop_snoop(hose, 1);
+}