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/pci-ecam.h>
  24 #include <linux/platform_device.h>
  25
  26 static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
  27                        struct list_head *resources, struct resource **bus_range)
  28 {
  29         int err, res_valid = 0;
  30         struct device_node *np = dev->of_node;
  31         resource_size_t iobase;
  32         struct resource_entry *win;
  33
  34         err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
  35         if (err)
  36                 return err;
  37
  38         err = devm_request_pci_bus_resources(dev, resources);
  39         if (err)
  40                 return err;
  41
  42         resource_list_for_each_entry(win, resources) {
  43                 struct resource *res = win->res;
  44
  45                 switch (resource_type(res)) {
  46                 case IORESOURCE_IO:
  47                         err = pci_remap_iospace(res, iobase);
  48                         if (err)
  49                                 dev_warn(dev, "error %d: failed to map resource %pR\n",
  50                                          err, res);
  51                         break;
  52                 case IORESOURCE_MEM:
  53                         res_valid |= !(res->flags & IORESOURCE_PREFETCH);
  54                         break;
  55                 case IORESOURCE_BUS:
  56                         *bus_range = res;
  57                         break;
  58                 }
  59         }
  60
  61         if (res_valid)
  62                 return 0;
  63
  64         dev_err(dev, "non-prefetchable memory resource required\n");
  65         return -EINVAL;
  66 }
  67
  68 static void gen_pci_unmap_cfg(void *ptr)
  69 {
  70         pci_ecam_free((struct pci_config_window *)ptr);
  71 }
  72
  73 static struct pci_config_window *gen_pci_init(struct device *dev,
  74                 struct list_head *resources, struct pci_ecam_ops *ops)
  75 {
  76         int err;
  77         struct resource cfgres;
  78         struct resource *bus_range = NULL;
  79         struct pci_config_window *cfg;
  80
  81         /* Parse our PCI ranges and request their resources */
  82         err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
  83         if (err)
  84                 goto err_out;
  85
  86         err = of_address_to_resource(dev->of_node, 0, &cfgres);
  87         if (err) {
  88                 dev_err(dev, "missing \"reg\" property\n");
  89                 goto err_out;
  90         }
  91
  92         cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
  93         if (IS_ERR(cfg)) {
  94                 err = PTR_ERR(cfg);
  95                 goto err_out;
  96         }
  97
  98         err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
  99         if (err) {
 100                 gen_pci_unmap_cfg(cfg);
 101                 goto err_out;
 102         }
 103         return cfg;
 104
 105 err_out:
 106         pci_free_resource_list(resources);
 107         return ERR_PTR(err);
 108 }
 109
 110 int pci_host_common_probe(struct platform_device *pdev,
 111                           struct pci_ecam_ops *ops)
 112 {
 113         const char *type;
 114         struct device *dev = &pdev->dev;
 115         struct device_node *np = dev->of_node;
 116         struct pci_bus *bus, *child;
 117         struct pci_config_window *cfg;
 118         struct list_head resources;
 119
 120         type = of_get_property(np, "device_type", NULL);
 121         if (!type || strcmp(type, "pci")) {
 122                 dev_err(dev, "invalid \"device_type\" %s\n", type);
 123                 return -EINVAL;
 124         }
 125
 126         of_pci_check_probe_only();
 127
 128         /* Parse and map our Configuration Space windows */
 129         INIT_LIST_HEAD(&resources);
 130         cfg = gen_pci_init(dev, &resources, ops);
 131         if (IS_ERR(cfg))
 132                 return PTR_ERR(cfg);
 133
 134         /* Do not reassign resources if probe only */
 135         if (!pci_has_flag(PCI_PROBE_ONLY))
 136                 pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
 137
 138         bus = pci_scan_root_bus(dev, cfg->busr.start, &ops->pci_ops, cfg,
 139                                 &resources);
 140         if (!bus) {
 141                 dev_err(dev, "Scanning rootbus failed");
 142                 return -ENODEV;
 143         }
 144
 145         pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
 146
 147         /*
 148          * We insert PCI resources into the iomem_resource and
 149          * ioport_resource trees in either pci_bus_claim_resources()
 150          * or pci_bus_assign_resources().
 151          */
 152         if (pci_has_flag(PCI_PROBE_ONLY)) {
 153                 pci_bus_claim_resources(bus);
 154         } else {
 155                 pci_bus_size_bridges(bus);
 156                 pci_bus_assign_resources(bus);
 157
 158                 list_for_each_entry(child, &bus->children, node)
 159                         pcie_bus_configure_settings(child);
 160         }
 161
 162         pci_bus_add_devices(bus);
 163         return 0;
 164 }
 165
 166 MODULE_DESCRIPTION("Generic PCI host driver common code");
 167 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
 168 MODULE_LICENSE("GPL v2");