drivers/pci/host/pci-host-generic.c - linux - Git at Google

 /*
  * 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 int gen_pci_config_read(struct pci_bus *bus, unsigned int devfn,
 				int where, int size, u32 *val)
 {
 	void __iomem *addr;
 	struct pci_sys_data *sys = bus->sysdata;
 	struct gen_pci *pci = sys->private_data;

 	addr = pci->cfg.ops->map_bus(bus, devfn, where);

 	switch (size) {
 	case 1:
 		*val = readb(addr);
 		break;
 	case 2:
 		*val = readw(addr);
 		break;
 	default:
 		*val = readl(addr);
 	}

 	return PCIBIOS_SUCCESSFUL;
 }

 static int gen_pci_config_write(struct pci_bus *bus, unsigned int devfn,
 				 int where, int size, u32 val)
 {
 	void __iomem *addr;
 	struct pci_sys_data *sys = bus->sysdata;
 	struct gen_pci *pci = sys->private_data;

 	addr = pci->cfg.ops->map_bus(bus, devfn, where);

 	switch (size) {
 	case 1:
 		writeb(val, addr);
 		break;
 	case 2:
 		writew(val, addr);
 		break;
 	default:
 		writel(val, addr);
 	}

 	return PCIBIOS_SUCCESSFUL;
 }

 static struct pci_ops gen_pci_ops = {
 	.read	= gen_pci_config_read,
 	.write	= gen_pci_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 int gen_pci_calc_io_offset(struct device *dev,
 				  struct of_pci_range *range,
 				  struct resource *res,
 				  resource_size_t *offset)
 {
 	static atomic_t wins = ATOMIC_INIT(0);
 	int err, idx, max_win;
 	unsigned int window;

 	if (!PAGE_ALIGNED(range->cpu_addr))
 		return -EINVAL;

 	max_win = (IO_SPACE_LIMIT + 1) / SZ_64K;
 	idx = atomic_inc_return(&wins);
 	if (idx > max_win)
 		return -ENOSPC;

 	window = (idx - 1) * SZ_64K;
 	err = pci_ioremap_io(window, range->cpu_addr);
 	if (err)
 		return err;

 	of_pci_range_to_resource(range, dev->of_node, res);
 	res->start = window;
 	res->end = res->start + range->size - 1;
 	*offset = window - range->pci_addr;
 	return 0;
 }

 static int gen_pci_calc_mem_offset(struct device *dev,
 				   struct of_pci_range *range,
 				   struct resource *res,
 				   resource_size_t *offset)
 {
 	of_pci_range_to_resource(range, dev->of_node, res);
 	*offset = range->cpu_addr - range->pci_addr;
 	return 0;
 }

 static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
 {
 	struct pci_host_bridge_window *win;

 	list_for_each_entry(win, &pci->resources, list)
 		release_resource(win->res);

 	pci_free_resource_list(&pci->resources);
 }

 static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
 {
 	struct of_pci_range range;
 	struct of_pci_range_parser parser;
 	int err, res_valid = 0;
 	struct device *dev = pci->host.dev.parent;
 	struct device_node *np = dev->of_node;

 	if (of_pci_range_parser_init(&parser, np)) {
 		dev_err(dev, "missing \"ranges\" property\n");
 		return -EINVAL;
 	}

 	for_each_of_pci_range(&parser, &range) {
 		struct resource *parent, *res;
 		resource_size_t offset;
 		u32 restype = range.flags & IORESOURCE_TYPE_BITS;

 		res = devm_kmalloc(dev, sizeof(*res), GFP_KERNEL);
 		if (!res) {
 			err = -ENOMEM;
 			goto out_release_res;
 		}

 		switch (restype) {
 		case IORESOURCE_IO:
 			parent = &ioport_resource;
 			err = gen_pci_calc_io_offset(dev, &range, res, &offset);
 			break;
 		case IORESOURCE_MEM:
 			parent = &iomem_resource;
 			err = gen_pci_calc_mem_offset(dev, &range, res, &offset);
 			res_valid |= !(res->flags & IORESOURCE_PREFETCH || err);
 			break;
 		default:
 			err = -EINVAL;
 			continue;
 		}

 		if (err) {
 			dev_warn(dev,
 				 "error %d: failed to add resource [type 0x%x, %lld bytes]\n",
 				 err, restype, range.size);
 			continue;
 		}

 		err = request_resource(parent, res);
 		if (err)
 			goto out_release_res;

 		pci_add_resource_offset(&pci->resources, res, offset);
 	}

 	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;

 	if (of_pci_parse_bus_range(np, &pci->cfg.bus_range))
 		pci->cfg.bus_range = (struct resource) {
 			.name	= np->name,
 			.start	= 0,
 			.end	= 0xff,
 			.flags	= IORESOURCE_BUS,
 		};

 	err = of_address_to_resource(np, 0, &pci->cfg.res);
 	if (err) {
 		dev_err(dev, "missing \"reg\" property\n");
 		return err;
 	}

 	pci->cfg.win = devm_kcalloc(dev, resource_size(&pci->cfg.bus_range),
 				    sizeof(*pci->cfg.win), GFP_KERNEL);
 	if (!pci->cfg.win)
 		return -ENOMEM;

 	/* 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);

 	/* 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;
 	}

 	/* Register bus resource */
 	pci_add_resource(&pci->resources, bus_range);
 	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;
 	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");
	/*
	* 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 int gen_pci_config_read(struct pci_bus *bus, unsigned int devfn,
	int where, int size, u32 *val)
	{
	void __iomem *addr;
	struct pci_sys_data *sys = bus->sysdata;
	struct gen_pci *pci = sys->private_data;

	addr = pci->cfg.ops->map_bus(bus, devfn, where);

	switch (size) {
	case 1:
	*val = readb(addr);
	break;
	case 2:
	*val = readw(addr);
	break;
	default:
	*val = readl(addr);
	}

	return PCIBIOS_SUCCESSFUL;
	}

	static int gen_pci_config_write(struct pci_bus *bus, unsigned int devfn,
	int where, int size, u32 val)
	{
	void __iomem *addr;
	struct pci_sys_data *sys = bus->sysdata;
	struct gen_pci *pci = sys->private_data;

	addr = pci->cfg.ops->map_bus(bus, devfn, where);

	switch (size) {
	case 1:
	writeb(val, addr);
	break;
	case 2:
	writew(val, addr);
	break;
	default:
	writel(val, addr);
	}

	return PCIBIOS_SUCCESSFUL;
	}

	static struct pci_ops gen_pci_ops = {
	.read = gen_pci_config_read,
	.write = gen_pci_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 int gen_pci_calc_io_offset(struct device *dev,
	struct of_pci_range *range,
	struct resource *res,
	resource_size_t *offset)
	{
	static atomic_t wins = ATOMIC_INIT(0);
	int err, idx, max_win;
	unsigned int window;

	if (!PAGE_ALIGNED(range->cpu_addr))
	return -EINVAL;

	max_win = (IO_SPACE_LIMIT + 1) / SZ_64K;
	idx = atomic_inc_return(&wins);
	if (idx > max_win)
	return -ENOSPC;

	window = (idx - 1) * SZ_64K;
	err = pci_ioremap_io(window, range->cpu_addr);
	if (err)
	return err;

	of_pci_range_to_resource(range, dev->of_node, res);
	res->start = window;
	res->end = res->start + range->size - 1;
	*offset = window - range->pci_addr;
	return 0;
	}

	static int gen_pci_calc_mem_offset(struct device *dev,
	struct of_pci_range *range,
	struct resource *res,
	resource_size_t *offset)
	{
	of_pci_range_to_resource(range, dev->of_node, res);
	*offset = range->cpu_addr - range->pci_addr;
	return 0;
	}

	static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
	{
	struct pci_host_bridge_window *win;

	list_for_each_entry(win, &pci->resources, list)
	release_resource(win->res);

	pci_free_resource_list(&pci->resources);
	}

	static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
	{
	struct of_pci_range range;
	struct of_pci_range_parser parser;
	int err, res_valid = 0;
	struct device *dev = pci->host.dev.parent;
	struct device_node *np = dev->of_node;

	if (of_pci_range_parser_init(&parser, np)) {
	dev_err(dev, "missing \"ranges\" property\n");
	return -EINVAL;
	}

	for_each_of_pci_range(&parser, &range) {
	struct resource parent, res;
	resource_size_t offset;
	u32 restype = range.flags & IORESOURCE_TYPE_BITS;

	res = devm_kmalloc(dev, sizeof(*res), GFP_KERNEL);
	if (!res) {
	err = -ENOMEM;
	goto out_release_res;
	}

	switch (restype) {
	case IORESOURCE_IO:
	parent = &ioport_resource;
	err = gen_pci_calc_io_offset(dev, &range, res, &offset);
	break;
	case IORESOURCE_MEM:
	parent = &iomem_resource;
	err = gen_pci_calc_mem_offset(dev, &range, res, &offset);
	res_valid \|= !(res->flags & IORESOURCE_PREFETCH \|\| err);
	break;
	default:
	err = -EINVAL;
	continue;
	}

	if (err) {
	dev_warn(dev,
	"error %d: failed to add resource [type 0x%x, %lld bytes]\n",
	err, restype, range.size);
	continue;
	}

	err = request_resource(parent, res);
	if (err)
	goto out_release_res;

	pci_add_resource_offset(&pci->resources, res, offset);
	}

	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;

	if (of_pci_parse_bus_range(np, &pci->cfg.bus_range))
	pci->cfg.bus_range = (struct resource) {
	.name = np->name,
	.start = 0,
	.end = 0xff,
	.flags = IORESOURCE_BUS,
	};

	err = of_address_to_resource(np, 0, &pci->cfg.res);
	if (err) {
	dev_err(dev, "missing \"reg\" property\n");
	return err;
	}

	pci->cfg.win = devm_kcalloc(dev, resource_size(&pci->cfg.bus_range),
	sizeof(*pci->cfg.win), GFP_KERNEL);
	if (!pci->cfg.win)
	return -ENOMEM;

	/* 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);

	/* 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;
	}

	/* Register bus resource */
	pci_add_resource(&pci->resources, bus_range);
	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;
	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");