drivers/of/of_pci.c

   1 #include <linux/kernel.h>
   2 #include <linux/export.h>
   3 #include <linux/of.h>
   4 #include <linux/of_address.h>
   5 #include <linux/of_device.h>
   6 #include <linux/of_pci.h>
   7 #include <linux/slab.h>
   8
   9 static inline int __of_pci_pci_compare(struct device_node *node,
  10                                        unsigned int data)
  11 {
  12         int devfn;
  13
  14         devfn = of_pci_get_devfn(node);
  15         if (devfn < 0)
  16                 return 0;
  17
  18         return devfn == data;
  19 }
  20
  21 struct device_node *of_pci_find_child_device(struct device_node *parent,
  22                                              unsigned int devfn)
  23 {
  24         struct device_node *node, *node2;
  25
  26         for_each_child_of_node(parent, node) {
  27                 if (__of_pci_pci_compare(node, devfn))
  28                         return node;
  29                 /*
  30                  * Some OFs create a parent node "multifunc-device" as
  31                  * a fake root for all functions of a multi-function
  32                  * device we go down them as well.
  33                  */
  34                 if (!strcmp(node->name, "multifunc-device")) {
  35                         for_each_child_of_node(node, node2) {
  36                                 if (__of_pci_pci_compare(node2, devfn)) {
  37                                         of_node_put(node);
  38                                         return node2;
  39                                 }
  40                         }
  41                 }
  42         }
  43         return NULL;
  44 }
  45 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
  46
  47 /**
  48  * of_pci_get_devfn() - Get device and function numbers for a device node
  49  * @np: device node
  50  *
  51  * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
  52  * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
  53  * and function numbers respectively. On error a negative error code is
  54  * returned.
  55  */
  56 int of_pci_get_devfn(struct device_node *np)
  57 {
  58         unsigned int size;
  59         const __be32 *reg;
  60
  61         reg = of_get_property(np, "reg", &size);
  62
  63         if (!reg || size < 5 * sizeof(__be32))
  64                 return -EINVAL;
  65
  66         return (be32_to_cpup(reg) >> 8) & 0xff;
  67 }
  68 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
  69
  70 /**
  71  * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
  72  * @node: device node
  73  * @res: address to a struct resource to return the bus-range
  74  *
  75  * Returns 0 on success or a negative error-code on failure.
  76  */
  77 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
  78 {
  79         const __be32 *values;
  80         int len;
  81
  82         values = of_get_property(node, "bus-range", &len);
  83         if (!values || len < sizeof(*values) * 2)
  84                 return -EINVAL;
  85
  86         res->name = node->name;
  87         res->start = be32_to_cpup(values++);
  88         res->end = be32_to_cpup(values);
  89         res->flags = IORESOURCE_BUS;
  90
  91         return 0;
  92 }
  93 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
  94
  95 /**
  96  * This function will try to obtain the host bridge domain number by
  97  * finding a property called "linux,pci-domain" of the given device node.
  98  *
  99  * @node: device tree node with the domain information
 100  *
 101  * Returns the associated domain number from DT in the range [0-0xffff], or
 102  * a negative value if the required property is not found.
 103  */
 104 int of_get_pci_domain_nr(struct device_node *node)
 105 {
 106         const __be32 *value;
 107         int len;
 108         u16 domain;
 109
 110         value = of_get_property(node, "linux,pci-domain", &len);
 111         if (!value || len < sizeof(*value))
 112                 return -EINVAL;
 113
 114         domain = (u16)be32_to_cpup(value);
 115
 116         return domain;
 117 }
 118 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
 119
 120 /**
 121  * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
 122  *                           is present and valid
 123  */
 124 void of_pci_check_probe_only(void)
 125 {
 126         u32 val;
 127         int ret;
 128
 129         ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
 130         if (ret) {
 131                 if (ret == -ENODATA || ret == -EOVERFLOW)
 132                         pr_warn("linux,pci-probe-only without valid value, ignoring\n");
 133                 return;
 134         }
 135
 136         if (val)
 137                 pci_add_flags(PCI_PROBE_ONLY);
 138         else
 139                 pci_clear_flags(PCI_PROBE_ONLY);
 140
 141         pr_info("PCI: PROBE_ONLY %sabled\n", val ? "en" : "dis");
 142 }
 143 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
 144
 145 #if defined(CONFIG_OF_ADDRESS)
 146 /**
 147  * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
 148  * @dev: device node of the host bridge having the range property
 149  * @busno: bus number associated with the bridge root bus
 150  * @bus_max: maximum number of buses for this bridge
 151  * @resources: list where the range of resources will be added after DT parsing
 152  * @io_base: pointer to a variable that will contain on return the physical
 153  * address for the start of the I/O range. Can be NULL if the caller doesn't
 154  * expect IO ranges to be present in the device tree.
 155  *
 156  * It is the caller's job to free the @resources list.
 157  *
 158  * This function will parse the "ranges" property of a PCI host bridge device
 159  * node and setup the resource mapping based on its content. It is expected
 160  * that the property conforms with the Power ePAPR document.
 161  *
 162  * It returns zero if the range parsing has been successful or a standard error
 163  * value if it failed.
 164  */
 165 int of_pci_get_host_bridge_resources(struct device_node *dev,
 166                         unsigned char busno, unsigned char bus_max,
 167                         struct list_head *resources, resource_size_t *io_base)
 168 {
 169         struct resource_entry *window;
 170         struct resource *res;
 171         struct resource *bus_range;
 172         struct of_pci_range range;
 173         struct of_pci_range_parser parser;
 174         char range_type[4];
 175         int err;
 176
 177         if (io_base)
 178                 *io_base = (resource_size_t)OF_BAD_ADDR;
 179
 180         bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
 181         if (!bus_range)
 182                 return -ENOMEM;
 183
 184         pr_info("PCI host bridge %s ranges:\n", dev->full_name);
 185
 186         err = of_pci_parse_bus_range(dev, bus_range);
 187         if (err) {
 188                 bus_range->start = busno;
 189                 bus_range->end = bus_max;
 190                 bus_range->flags = IORESOURCE_BUS;
 191                 pr_info("  No bus range found for %s, using %pR\n",
 192                         dev->full_name, bus_range);
 193         } else {
 194                 if (bus_range->end > bus_range->start + bus_max)
 195                         bus_range->end = bus_range->start + bus_max;
 196         }
 197         pci_add_resource(resources, bus_range);
 198
 199         /* Check for ranges property */
 200         err = of_pci_range_parser_init(&parser, dev);
 201         if (err)
 202                 goto parse_failed;
 203
 204         pr_debug("Parsing ranges property...\n");
 205         for_each_of_pci_range(&parser, &range) {
 206                 /* Read next ranges element */
 207                 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
 208                         snprintf(range_type, 4, " IO");
 209                 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
 210                         snprintf(range_type, 4, "MEM");
 211                 else
 212                         snprintf(range_type, 4, "err");
 213                 pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
 214                         range.cpu_addr, range.cpu_addr + range.size - 1,
 215                         range.pci_addr);
 216
 217                 /*
 218                  * If we failed translation or got a zero-sized region
 219                  * then skip this range
 220                  */
 221                 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 222                         continue;
 223
 224                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 225                 if (!res) {
 226                         err = -ENOMEM;
 227                         goto parse_failed;
 228                 }
 229
 230                 err = of_pci_range_to_resource(&range, dev, res);
 231                 if (err) {
 232                         kfree(res);
 233                         continue;
 234                 }
 235
 236                 if (resource_type(res) == IORESOURCE_IO) {
 237                         if (!io_base) {
 238                                 pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
 239                                         dev->full_name);
 240                                 err = -EINVAL;
 241                                 goto conversion_failed;
 242                         }
 243                         if (*io_base != (resource_size_t)OF_BAD_ADDR)
 244                                 pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
 245                                         dev->full_name);
 246                         *io_base = range.cpu_addr;
 247                 }
 248
 249                 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
 250         }
 251
 252         return 0;
 253
 254 conversion_failed:
 255         kfree(res);
 256 parse_failed:
 257         resource_list_for_each_entry(window, resources)
 258                 kfree(window->res);
 259         pci_free_resource_list(resources);
 260         return err;
 261 }
 262 EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
 263 #endif /* CONFIG_OF_ADDRESS */
 264
 265 #ifdef CONFIG_PCI_MSI
 266
 267 static LIST_HEAD(of_pci_msi_chip_list);
 268 static DEFINE_MUTEX(of_pci_msi_chip_mutex);
 269
 270 int of_pci_msi_chip_add(struct msi_controller *chip)
 271 {
 272         if (!of_property_read_bool(chip->of_node, "msi-controller"))
 273                 return -EINVAL;
 274
 275         mutex_lock(&of_pci_msi_chip_mutex);
 276         list_add(&chip->list, &of_pci_msi_chip_list);
 277         mutex_unlock(&of_pci_msi_chip_mutex);
 278
 279         return 0;
 280 }
 281 EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);
 282
 283 void of_pci_msi_chip_remove(struct msi_controller *chip)
 284 {
 285         mutex_lock(&of_pci_msi_chip_mutex);
 286         list_del(&chip->list);
 287         mutex_unlock(&of_pci_msi_chip_mutex);
 288 }
 289 EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);
 290
 291 struct msi_controller *of_pci_find_msi_chip_by_node(struct device_node *of_node)
 292 {
 293         struct msi_controller *c;
 294
 295         mutex_lock(&of_pci_msi_chip_mutex);
 296         list_for_each_entry(c, &of_pci_msi_chip_list, list) {
 297                 if (c->of_node == of_node) {
 298                         mutex_unlock(&of_pci_msi_chip_mutex);
 299                         return c;
 300                 }
 301         }
 302         mutex_unlock(&of_pci_msi_chip_mutex);
 303
 304         return NULL;
 305 }
 306 EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);
 307
 308 #endif /* CONFIG_PCI_MSI */