From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/pci/host/pci-host-generic.c | 276 ++++++++++++++++++++++++++++++++++++ 1 file changed, 276 insertions(+) create mode 100644 drivers/pci/host/pci-host-generic.c (limited to 'drivers/pci/host/pci-host-generic.c') 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 . + * + * Copyright (C) 2014 ARM Limited + * + * Author: Will Deacon + */ + +#include +#include +#include +#include +#include + +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 "); +MODULE_LICENSE("GPL v2"); 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