drivers/pci/host/pci-host-common.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License version 2 as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  13  *
  14  * Copyright (C) 2014 ARM Limited
  15  *
  16  * Author: Will Deacon <will.deacon@arm.com>
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_pci.h>
  23 #include <linux/platform_device.h>
  24
  25 #include "../ecam.h"
  26
  27 static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
  28                        struct list_head *resources, struct resource **bus_range)
  29 {
  30         int err, res_valid = 0;
  31         struct device_node *np = dev->of_node;
  32         resource_size_t iobase;
  33         struct resource_entry *win;
  34
  35         err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
  36         if (err)
  37                 return err;
  38
  39         err = devm_request_pci_bus_resources(dev, resources);
  40         if (err)
  41                 goto out_release_res;
  42
  43         resource_list_for_each_entry(win, resources) {
  44                 struct resource *res = win->res;
  45
  46                 switch (resource_type(res)) {
  47                 case IORESOURCE_IO:
  48                         err = pci_remap_iospace(res, iobase);
  49                         if (err) {
  50                                 dev_warn(dev, "error %d: failed to map resource %pR\n",
  51                                          err, res);
  52                                 continue;
  53                         }
  54                         break;
  55                 case IORESOURCE_MEM:
  56                         res_valid |= !(res->flags & IORESOURCE_PREFETCH);
  57                         break;
  58                 case IORESOURCE_BUS:
  59                         *bus_range = res;
  60                 default:
  61                         continue;
  62                 }
  63         }
  64
  65         if (!res_valid) {
  66                 dev_err(dev, "non-prefetchable memory resource required\n");
  67                 err = -EINVAL;
  68                 goto out_release_res;
  69         }
  70
  71         return 0;
  72
  73 out_release_res:
  74         return err;
  75 }
  76
  77 static void gen_pci_unmap_cfg(void *ptr)
  78 {
  79         pci_ecam_free((struct pci_config_window *)ptr);
  80 }
  81
  82 static struct pci_config_window *gen_pci_init(struct device *dev,
  83                 struct list_head *resources, struct pci_ecam_ops *ops)
  84 {
  85         int err;
  86         struct resource cfgres;
  87         struct resource *bus_range = NULL;
  88         struct pci_config_window *cfg;
  89
  90         /* Parse our PCI ranges and request their resources */
  91         err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
  92         if (err)
  93                 goto err_out;
  94
  95         err = of_address_to_resource(dev->of_node, 0, &cfgres);
  96         if (err) {
  97                 dev_err(dev, "missing \"reg\" property\n");
  98                 goto err_out;
  99         }
 100
 101         cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
 102         if (IS_ERR(cfg)) {
 103                 err = PTR_ERR(cfg);
 104                 goto err_out;
 105         }
 106
 107         err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
 108         if (err) {
 109                 gen_pci_unmap_cfg(cfg);
 110                 goto err_out;
 111         }
 112         return cfg;
 113
 114 err_out:
 115         pci_free_resource_list(resources);
 116         return ERR_PTR(err);
 117 }
 118
 119 int pci_host_common_probe(struct platform_device *pdev,
 120                           struct pci_ecam_ops *ops)
 121 {
 122         const char *type;
 123         struct device *dev = &pdev->dev;
 124         struct device_node *np = dev->of_node;
 125         struct pci_bus *bus, *child;
 126         struct pci_config_window *cfg;
 127         struct list_head resources;
 128
 129         type = of_get_property(np, "device_type", NULL);
 130         if (!type || strcmp(type, "pci")) {
 131                 dev_err(dev, "invalid \"device_type\" %s\n", type);
 132                 return -EINVAL;
 133         }
 134
 135         of_pci_check_probe_only();
 136
 137         /* Parse and map our Configuration Space windows */
 138         INIT_LIST_HEAD(&resources);
 139         cfg = gen_pci_init(dev, &resources, ops);
 140         if (IS_ERR(cfg))
 141                 return PTR_ERR(cfg);
 142
 143         /* Do not reassign resources if probe only */
 144         if (!pci_has_flag(PCI_PROBE_ONLY))
 145                 pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
 146
 147         bus = pci_scan_root_bus(dev, cfg->busr.start, &ops->pci_ops, cfg,
 148                                 &resources);
 149         if (!bus) {
 150                 dev_err(dev, "Scanning rootbus failed");
 151                 return -ENODEV;
 152         }
 153
 154         pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
 155
 156         if (!pci_has_flag(PCI_PROBE_ONLY)) {
 157                 pci_bus_size_bridges(bus);
 158                 pci_bus_assign_resources(bus);
 159
 160                 list_for_each_entry(child, &bus->children, node)
 161                         pcie_bus_configure_settings(child);
 162         }
 163
 164         pci_bus_add_devices(bus);
 165         return 0;
 166 }
 167
 168 MODULE_DESCRIPTION("Generic PCI host driver common code");
 169 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
 170 MODULE_LICENSE("GPL v2");