1 files changed, 93 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-al.c b/drivers/pci/controller/dwc/pcie-al.c
new file mode 100644
index 000000000000..3ab58f0584a8
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-al.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Amazon's Annapurna Labs IP (used in chips
+ * such as Graviton and Alpine)
+ *
+ * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Author: Jonathan Chocron <jonnyc@amazon.com>
+ */
+
+#include <linux/pci.h>
+#include <linux/pci-ecam.h>
+#include <linux/pci-acpi.h>
+#include "../../pci.h"
+
+#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
+
+struct al_pcie_acpi  {
+	void __iomem *dbi_base;
+};
+
+static void __iomem *al_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
+				     int where)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+	struct al_pcie_acpi *pcie = cfg->priv;
+	void __iomem *dbi_base = pcie->dbi_base;
+
+	if (bus->number == cfg->busr.start) {
+		/*
+		 * The DW PCIe core doesn't filter out transactions to other
+		 * devices/functions on the root bus num, so we do this here.
+		 */
+		if (PCI_SLOT(devfn) > 0)
+			return NULL;
+		else
+			return dbi_base + where;
+	}
+
+	return pci_ecam_map_bus(bus, devfn, where);
+}
+
+static int al_pcie_init(struct pci_config_window *cfg)
+{
+	struct device *dev = cfg->parent;
+	struct acpi_device *adev = to_acpi_device(dev);
+	struct acpi_pci_root *root = acpi_driver_data(adev);
+	struct al_pcie_acpi *al_pcie;
+	struct resource *res;
+	int ret;
+
+	al_pcie = devm_kzalloc(dev, sizeof(*al_pcie), GFP_KERNEL);
+	if (!al_pcie)
+		return -ENOMEM;
+
+	res = devm_kzalloc(dev, sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return -ENOMEM;
+
+	ret = acpi_get_rc_resources(dev, "AMZN0001", root->segment, res);
+	if (ret) {
+		dev_err(dev, "can't get rc dbi base address for SEG %d\n",
+			root->segment);
+		return ret;
+	}
+
+	dev_dbg(dev, "Root port dbi res: %pR\n", res);
+
+	al_pcie->dbi_base = devm_pci_remap_cfg_resource(dev, res);
+	if (IS_ERR(al_pcie->dbi_base)) {
+		long err = PTR_ERR(al_pcie->dbi_base);
+
+		dev_err(dev, "couldn't remap dbi base %pR (err:%ld)\n",
+			res, err);
+		return err;
+	}
+
+	cfg->priv = al_pcie;
+
+	return 0;
+}
+
+struct pci_ecam_ops al_pcie_ops = {
+	.bus_shift    = 20,
+	.init         =  al_pcie_init,
+	.pci_ops      = {
+		.map_bus    = al_pcie_map_bus,
+		.read       = pci_generic_config_read,
+		.write      = pci_generic_config_write,
+	}
+};
+
+#endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */