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 "pci-host-common.h"
  26
  27 static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
  28 {
  29         pci_free_resource_list(&pci->resources);
  30 }
  31
  32 static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
  33 {
  34         int err, res_valid = 0;
  35         struct device *dev = pci->host.dev.parent;
  36         struct device_node *np = dev->of_node;
  37         resource_size_t iobase;
  38         struct resource_entry *win;
  39
  40         err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
  41                                                &iobase);
  42         if (err)
  43                 return err;
  44
  45         resource_list_for_each_entry(win, &pci->resources) {
  46                 struct resource *parent, *res = win->res;
  47
  48                 switch (resource_type(res)) {
  49                 case IORESOURCE_IO:
  50                         parent = &ioport_resource;
  51                         err = pci_remap_iospace(res, iobase);
  52                         if (err) {
  53                                 dev_warn(dev, "error %d: failed to map resource %pR\n",
  54                                          err, res);
  55                                 continue;
  56                         }
  57                         break;
  58                 case IORESOURCE_MEM:
  59                         parent = &iomem_resource;
  60                         res_valid |= !(res->flags & IORESOURCE_PREFETCH);
  61                         break;
  62                 case IORESOURCE_BUS:
  63                         pci->cfg.bus_range = res;
  64                 default:
  65                         continue;
  66                 }
  67
  68                 err = devm_request_resource(dev, parent, res);
  69                 if (err)
  70                         goto out_release_res;
  71         }
  72
  73         if (!res_valid) {
  74                 dev_err(dev, "non-prefetchable memory resource required\n");
  75                 err = -EINVAL;
  76                 goto out_release_res;
  77         }
  78
  79         return 0;
  80
  81 out_release_res:
  82         gen_pci_release_of_pci_ranges(pci);
  83         return err;
  84 }
  85
  86 static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
  87 {
  88         int err;
  89         u8 bus_max;
  90         resource_size_t busn;
  91         struct resource *bus_range;
  92         struct device *dev = pci->host.dev.parent;
  93         struct device_node *np = dev->of_node;
  94         u32 sz = 1 << pci->cfg.ops->bus_shift;
  95
  96         err = of_address_to_resource(np, 0, &pci->cfg.res);
  97         if (err) {
  98                 dev_err(dev, "missing \"reg\" property\n");
  99                 return err;
 100         }
 101
 102         /* Limit the bus-range to fit within reg */
 103         bus_max = pci->cfg.bus_range->start +
 104                   (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
 105         pci->cfg.bus_range->end = min_t(resource_size_t,
 106                                         pci->cfg.bus_range->end, bus_max);
 107
 108         pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
 109                                     sizeof(*pci->cfg.win), GFP_KERNEL);
 110         if (!pci->cfg.win)
 111                 return -ENOMEM;
 112
 113         /* Map our Configuration Space windows */
 114         if (!devm_request_mem_region(dev, pci->cfg.res.start,
 115                                      resource_size(&pci->cfg.res),
 116                                      "Configuration Space"))
 117                 return -ENOMEM;
 118
 119         bus_range = pci->cfg.bus_range;
 120         for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
 121                 u32 idx = busn - bus_range->start;
 122
 123                 pci->cfg.win[idx] = devm_ioremap(dev,
 124                                                  pci->cfg.res.start + idx * sz,
 125                                                  sz);
 126                 if (!pci->cfg.win[idx])
 127                         return -ENOMEM;
 128         }
 129
 130         return 0;
 131 }
 132
 133 int pci_host_common_probe(struct platform_device *pdev,
 134                           struct gen_pci *pci)
 135 {
 136         int err;
 137         const char *type;
 138         struct device *dev = &pdev->dev;
 139         struct device_node *np = dev->of_node;
 140         struct pci_bus *bus, *child;
 141
 142         type = of_get_property(np, "device_type", NULL);
 143         if (!type || strcmp(type, "pci")) {
 144                 dev_err(dev, "invalid \"device_type\" %s\n", type);
 145                 return -EINVAL;
 146         }
 147
 148         of_pci_check_probe_only();
 149
 150         pci->host.dev.parent = dev;
 151         INIT_LIST_HEAD(&pci->host.windows);
 152         INIT_LIST_HEAD(&pci->resources);
 153
 154         /* Parse our PCI ranges and request their resources */
 155         err = gen_pci_parse_request_of_pci_ranges(pci);
 156         if (err)
 157                 return err;
 158
 159         /* Parse and map our Configuration Space windows */
 160         err = gen_pci_parse_map_cfg_windows(pci);
 161         if (err) {
 162                 gen_pci_release_of_pci_ranges(pci);
 163                 return err;
 164         }
 165
 166         /* Do not reassign resources if probe only */
 167         if (!pci_has_flag(PCI_PROBE_ONLY))
 168                 pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
 169
 170
 171         bus = pci_scan_root_bus(dev, pci->cfg.bus_range->start,
 172                                 &pci->cfg.ops->ops, pci, &pci->resources);
 173         if (!bus) {
 174                 dev_err(dev, "Scanning rootbus failed");
 175                 return -ENODEV;
 176         }
 177
 178         pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
 179
 180         if (!pci_has_flag(PCI_PROBE_ONLY)) {
 181                 pci_bus_size_bridges(bus);
 182                 pci_bus_assign_resources(bus);
 183
 184                 list_for_each_entry(child, &bus->children, node)
 185                         pcie_bus_configure_settings(child);
 186         }
 187
 188         pci_bus_add_devices(bus);
 189         return 0;
 190 }
 191
 192 MODULE_DESCRIPTION("Generic PCI host driver common code");
 193 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
 194 MODULE_LICENSE("GPL v2");