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

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