diff options
Diffstat (limited to 'drivers/pci/host/pci-host-generic.c')
| -rw-r--r-- | drivers/pci/host/pci-host-generic.c | 388 |
1 files changed, 388 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 0000000..44fe6aa --- /dev/null +++ b/drivers/pci/host/pci-host-generic.c @@ -0,0 +1,388 @@ +/* + * 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", + .owner = THIS_MODULE, + .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("GPLv2"); |