1 files changed, 276 insertions, 0 deletions
diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
new file mode 100644
index 000000000..ba46e581d
--- /dev/null
+++ b/drivers/pci/host/pci-host-generic.c
@@ -0,0 +1,276 @@
+/*
+ * Simple, generic PCI host controller driver targetting firmware-initialised
+ * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright (C) 2014 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/platform_device.h>
+
+struct gen_pci_cfg_bus_ops {
+	u32 bus_shift;
+	void __iomem *(*map_bus)(struct pci_bus *, unsigned int, int);
+};
+
+struct gen_pci_cfg_windows {
+	struct resource				res;
+	struct resource				*bus_range;
+	void __iomem				**win;
+
+	const struct gen_pci_cfg_bus_ops	*ops;
+};
+
+struct gen_pci {
+	struct pci_host_bridge			host;
+	struct gen_pci_cfg_windows		cfg;
+	struct list_head			resources;
+};
+
+static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
+					     unsigned int devfn,
+					     int where)
+{
+	struct pci_sys_data *sys = bus->sysdata;
+	struct gen_pci *pci = sys->private_data;
+	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
+
+	return pci->cfg.win[idx] + ((devfn << 8) | where);
+}
+
+static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
+	.bus_shift	= 16,
+	.map_bus	= gen_pci_map_cfg_bus_cam,
+};
+
+static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
+					      unsigned int devfn,
+					      int where)
+{
+	struct pci_sys_data *sys = bus->sysdata;
+	struct gen_pci *pci = sys->private_data;
+	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
+
+	return pci->cfg.win[idx] + ((devfn << 12) | where);
+}
+
+static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
+	.bus_shift	= 20,
+	.map_bus	= gen_pci_map_cfg_bus_ecam,
+};
+
+static struct pci_ops gen_pci_ops = {
+	.read	= pci_generic_config_read,
+	.write	= pci_generic_config_write,
+};
+
+static const struct of_device_id gen_pci_of_match[] = {
+	{ .compatible = "pci-host-cam-generic",
+	  .data = &gen_pci_cfg_cam_bus_ops },
+
+	{ .compatible = "pci-host-ecam-generic",
+	  .data = &gen_pci_cfg_ecam_bus_ops },
+
+	{ },
+};
+MODULE_DEVICE_TABLE(of, gen_pci_of_match);
+
+static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
+{
+	pci_free_resource_list(&pci->resources);
+}
+
+static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
+{
+	int err, res_valid = 0;
+	struct device *dev = pci->host.dev.parent;
+	struct device_node *np = dev->of_node;
+	resource_size_t iobase;
+	struct resource_entry *win;
+
+	err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
+					       &iobase);
+	if (err)
+		return err;
+
+	resource_list_for_each_entry(win, &pci->resources) {
+		struct resource *parent, *res = win->res;
+
+		switch (resource_type(res)) {
+		case IORESOURCE_IO:
+			parent = &ioport_resource;
+			err = pci_remap_iospace(res, iobase);
+			if (err) {
+				dev_warn(dev, "error %d: failed to map resource %pR\n",
+					 err, res);
+				continue;
+			}
+			break;
+		case IORESOURCE_MEM:
+			parent = &iomem_resource;
+			res_valid |= !(res->flags & IORESOURCE_PREFETCH);
+			break;
+		case IORESOURCE_BUS:
+			pci->cfg.bus_range = res;
+		default:
+			continue;
+		}
+
+		err = devm_request_resource(dev, parent, res);
+		if (err)
+			goto out_release_res;
+	}
+
+	if (!res_valid) {
+		dev_err(dev, "non-prefetchable memory resource required\n");
+		err = -EINVAL;
+		goto out_release_res;
+	}
+
+	return 0;
+
+out_release_res:
+	gen_pci_release_of_pci_ranges(pci);
+	return err;
+}
+
+static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
+{
+	int err;
+	u8 bus_max;
+	resource_size_t busn;
+	struct resource *bus_range;
+	struct device *dev = pci->host.dev.parent;
+	struct device_node *np = dev->of_node;
+
+	err = of_address_to_resource(np, 0, &pci->cfg.res);
+	if (err) {
+		dev_err(dev, "missing \"reg\" property\n");
+		return err;
+	}
+
+	/* Limit the bus-range to fit within reg */
+	bus_max = pci->cfg.bus_range->start +
+		  (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
+	pci->cfg.bus_range->end = min_t(resource_size_t,
+					pci->cfg.bus_range->end, bus_max);
+
+	pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
+				    sizeof(*pci->cfg.win), GFP_KERNEL);
+	if (!pci->cfg.win)
+		return -ENOMEM;
+
+	/* Map our Configuration Space windows */
+	if (!devm_request_mem_region(dev, pci->cfg.res.start,
+				     resource_size(&pci->cfg.res),
+				     "Configuration Space"))
+		return -ENOMEM;
+
+	bus_range = pci->cfg.bus_range;
+	for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
+		u32 idx = busn - bus_range->start;
+		u32 sz = 1 << pci->cfg.ops->bus_shift;
+
+		pci->cfg.win[idx] = devm_ioremap(dev,
+						 pci->cfg.res.start + busn * sz,
+						 sz);
+		if (!pci->cfg.win[idx])
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int gen_pci_setup(int nr, struct pci_sys_data *sys)
+{
+	struct gen_pci *pci = sys->private_data;
+	list_splice_init(&pci->resources, &sys->resources);
+	return 1;
+}
+
+static int gen_pci_probe(struct platform_device *pdev)
+{
+	int err;
+	const char *type;
+	const struct of_device_id *of_id;
+	const int *prop;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+	struct hw_pci hw = {
+		.nr_controllers	= 1,
+		.private_data	= (void **)&pci,
+		.setup		= gen_pci_setup,
+		.map_irq	= of_irq_parse_and_map_pci,
+		.ops		= &gen_pci_ops,
+	};
+
+	if (!pci)
+		return -ENOMEM;
+
+	type = of_get_property(np, "device_type", NULL);
+	if (!type || strcmp(type, "pci")) {
+		dev_err(dev, "invalid \"device_type\" %s\n", type);
+		return -EINVAL;
+	}
+
+	prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
+	if (prop) {
+		if (*prop)
+			pci_add_flags(PCI_PROBE_ONLY);
+		else
+			pci_clear_flags(PCI_PROBE_ONLY);
+	}
+
+	of_id = of_match_node(gen_pci_of_match, np);
+	pci->cfg.ops = of_id->data;
+	gen_pci_ops.map_bus = pci->cfg.ops->map_bus;
+	pci->host.dev.parent = dev;
+	INIT_LIST_HEAD(&pci->host.windows);
+	INIT_LIST_HEAD(&pci->resources);
+
+	/* Parse our PCI ranges and request their resources */
+	err = gen_pci_parse_request_of_pci_ranges(pci);
+	if (err)
+		return err;
+
+	/* Parse and map our Configuration Space windows */
+	err = gen_pci_parse_map_cfg_windows(pci);
+	if (err) {
+		gen_pci_release_of_pci_ranges(pci);
+		return err;
+	}
+
+	pci_common_init_dev(dev, &hw);
+	return 0;
+}
+
+static struct platform_driver gen_pci_driver = {
+	.driver = {
+		.name = "pci-host-generic",
+		.of_match_table = gen_pci_of_match,
+	},
+	.probe = gen_pci_probe,
+};
+module_platform_driver(gen_pci_driver);
+
+MODULE_DESCRIPTION("Generic PCI host driver");
+MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
+MODULE_LICENSE("GPL v2");