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/*
* 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>
#include "pci-host-common.h"
static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
unsigned int devfn,
int where)
{
struct gen_pci *pci = bus->sysdata;
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,
.ops = {
.map_bus = gen_pci_map_cfg_bus_cam,
.read = pci_generic_config_read,
.write = pci_generic_config_write,
}
};
static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
unsigned int devfn,
int where)
{
struct gen_pci *pci = bus->sysdata;
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,
.ops = {
.map_bus = gen_pci_map_cfg_bus_ecam,
.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;
u32 sz = 1 << pci->cfg.ops->bus_shift;
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;
pci->cfg.win[idx] = devm_ioremap(dev,
pci->cfg.res.start + idx * sz,
sz);
if (!pci->cfg.win[idx])
return -ENOMEM;
}
return 0;
}
static int gen_pci_probe(struct platform_device *pdev)
{
int err;
const char *type;
const struct of_device_id *of_id;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
struct pci_bus *bus, *child;
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;
}
of_pci_check_probe_only();
of_id = of_match_node(gen_pci_of_match, np);
pci->cfg.ops = (struct gen_pci_cfg_bus_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;
}
/* Do not reassign resources if probe only */
if (!pci_has_flag(PCI_PROBE_ONLY))
pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
bus = pci_scan_root_bus(dev, pci->cfg.bus_range->start,
&pci->cfg.ops->ops, pci, &pci->resources);
if (!bus) {
dev_err(dev, "Scanning rootbus failed");
return -ENODEV;
}
pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
if (!pci_has_flag(PCI_PROBE_ONLY)) {
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
list_for_each_entry(child, &bus->children, node)
pcie_bus_configure_settings(child);
}
pci_bus_add_devices(bus);
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");
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