1 files changed, 57 insertions, 0 deletions
diff --git a/src/soc/amd/common/block/pci/pci_routing_info.c b/src/soc/amd/common/block/pci/pci_routing_info.c
new file mode 100644
index 000000000000..e0a696442e6e
--- /dev/null
+++ b/src/soc/amd/common/block/pci/pci_routing_info.c
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <amdblocks/amd_pci_util.h>
+#include <console/console.h>
+#include <device/pci_def.h>
+#include <types.h>
+
+enum pcie_swizzle_pin {
+	PIN_A,
+	PIN_B,
+	PIN_C,
+	PIN_D,
+};
+
+static const uint8_t pcie_swizzle_table[][4] = {
+	{PIN_A, PIN_B, PIN_C, PIN_D},
+	{PIN_B, PIN_C, PIN_D, PIN_A},
+	{PIN_C, PIN_D, PIN_A, PIN_B},
+	{PIN_D, PIN_A, PIN_B, PIN_C},
+};
+
+const struct pci_routing_info *get_pci_routing_info(unsigned int devfn)
+{
+	const struct pci_routing_info *routing_info;
+	size_t entries = 0;
+
+	routing_info = get_pci_routing_table(&entries);
+
+	if (!routing_info || !entries)
+		return NULL;
+
+	for (size_t i = 0; i < entries; ++i, ++routing_info)
+		if (routing_info->devfn == devfn)
+			return routing_info;
+
+	printk(BIOS_ERR, "Failed to find PCIe routing info for dev: %#x, fn: %#x\n",
+	       PCI_SLOT(devfn), PCI_FUNC(devfn));
+
+	return NULL;
+}
+
+unsigned int pci_calculate_irq(const struct pci_routing_info *routing_info,
+					      unsigned int pin)
+{
+	unsigned int irq;
+
+	if (routing_info->swizzle >= ARRAY_SIZE(pcie_swizzle_table))
+		die("%s: swizzle %u out of bounds\n", __func__, routing_info->swizzle);
+
+	if (pin >= ARRAY_SIZE(pcie_swizzle_table[routing_info->swizzle]))
+		die("%s: pin %u out of bounds\n", __func__, pin);
+
+	irq = routing_info->group * 4;
+	irq += pcie_swizzle_table[routing_info->swizzle][pin];
+
+	return irq;
+}