drivers/of/of_pci.c

   1 #define pr_fmt(fmt)     "OF: PCI: " fmt
   2
   3 #include <linux/kernel.h>
   4 #include <linux/export.h>
   5 #include <linux/of.h>
   6 #include <linux/of_address.h>
   7 #include <linux/of_device.h>
   8 #include <linux/of_pci.h>
   9 #include <linux/slab.h>
  10
  11 static inline int __of_pci_pci_compare(struct device_node *node,
  12                                        unsigned int data)
  13 {
  14         int devfn;
  15
  16         devfn = of_pci_get_devfn(node);
  17         if (devfn < 0)
  18                 return 0;
  19
  20         return devfn == data;
  21 }
  22
  23 struct device_node *of_pci_find_child_device(struct device_node *parent,
  24                                              unsigned int devfn)
  25 {
  26         struct device_node *node, *node2;
  27
  28         for_each_child_of_node(parent, node) {
  29                 if (__of_pci_pci_compare(node, devfn))
  30                         return node;
  31                 /*
  32                  * Some OFs create a parent node "multifunc-device" as
  33                  * a fake root for all functions of a multi-function
  34                  * device we go down them as well.
  35                  */
  36                 if (!strcmp(node->name, "multifunc-device")) {
  37                         for_each_child_of_node(node, node2) {
  38                                 if (__of_pci_pci_compare(node2, devfn)) {
  39                                         of_node_put(node);
  40                                         return node2;
  41                                 }
  42                         }
  43                 }
  44         }
  45         return NULL;
  46 }
  47 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
  48
  49 /**
  50  * of_pci_get_devfn() - Get device and function numbers for a device node
  51  * @np: device node
  52  *
  53  * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
  54  * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
  55  * and function numbers respectively. On error a negative error code is
  56  * returned.
  57  */
  58 int of_pci_get_devfn(struct device_node *np)
  59 {
  60         unsigned int size;
  61         const __be32 *reg;
  62
  63         reg = of_get_property(np, "reg", &size);
  64
  65         if (!reg || size < 5 * sizeof(__be32))
  66                 return -EINVAL;
  67
  68         return (be32_to_cpup(reg) >> 8) & 0xff;
  69 }
  70 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
  71
  72 /**
  73  * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
  74  * @node: device node
  75  * @res: address to a struct resource to return the bus-range
  76  *
  77  * Returns 0 on success or a negative error-code on failure.
  78  */
  79 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
  80 {
  81         const __be32 *values;
  82         int len;
  83
  84         values = of_get_property(node, "bus-range", &len);
  85         if (!values || len < sizeof(*values) * 2)
  86                 return -EINVAL;
  87
  88         res->name = node->name;
  89         res->start = be32_to_cpup(values++);
  90         res->end = be32_to_cpup(values);
  91         res->flags = IORESOURCE_BUS;
  92
  93         return 0;
  94 }
  95 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
  96
  97 /**
  98  * This function will try to obtain the host bridge domain number by
  99  * finding a property called "linux,pci-domain" of the given device node.
 100  *
 101  * @node: device tree node with the domain information
 102  *
 103  * Returns the associated domain number from DT in the range [0-0xffff], or
 104  * a negative value if the required property is not found.
 105  */
 106 int of_get_pci_domain_nr(struct device_node *node)
 107 {
 108         const __be32 *value;
 109         int len;
 110         u16 domain;
 111
 112         value = of_get_property(node, "linux,pci-domain", &len);
 113         if (!value || len < sizeof(*value))
 114                 return -EINVAL;
 115
 116         domain = (u16)be32_to_cpup(value);
 117
 118         return domain;
 119 }
 120 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
 121
 122 /**
 123  * This function will try to find the limitation of link speed by finding
 124  * a property called "max-link-speed" of the given device node.
 125  *
 126  * @node: device tree node with the max link speed information
 127  *
 128  * Returns the associated max link speed from DT, or a negative value if the
 129  * required property is not found or is invalid.
 130  */
 131 int of_pci_get_max_link_speed(struct device_node *node)
 132 {
 133         u32 max_link_speed;
 134
 135         if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
 136             max_link_speed > 4)
 137                 return -EINVAL;
 138
 139         return max_link_speed;
 140 }
 141 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
 142
 143 /**
 144  * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
 145  *                           is present and valid
 146  */
 147 void of_pci_check_probe_only(void)
 148 {
 149         u32 val;
 150         int ret;
 151
 152         ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
 153         if (ret) {
 154                 if (ret == -ENODATA || ret == -EOVERFLOW)
 155                         pr_warn("linux,pci-probe-only without valid value, ignoring\n");
 156                 return;
 157         }
 158
 159         if (val)
 160                 pci_add_flags(PCI_PROBE_ONLY);
 161         else
 162                 pci_clear_flags(PCI_PROBE_ONLY);
 163
 164         pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
 165 }
 166 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
 167
 168 #if defined(CONFIG_OF_ADDRESS)
 169 /**
 170  * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
 171  * @dev: device node of the host bridge having the range property
 172  * @busno: bus number associated with the bridge root bus
 173  * @bus_max: maximum number of buses for this bridge
 174  * @resources: list where the range of resources will be added after DT parsing
 175  * @io_base: pointer to a variable that will contain on return the physical
 176  * address for the start of the I/O range. Can be NULL if the caller doesn't
 177  * expect IO ranges to be present in the device tree.
 178  *
 179  * It is the caller's job to free the @resources list.
 180  *
 181  * This function will parse the "ranges" property of a PCI host bridge device
 182  * node and setup the resource mapping based on its content. It is expected
 183  * that the property conforms with the Power ePAPR document.
 184  *
 185  * It returns zero if the range parsing has been successful or a standard error
 186  * value if it failed.
 187  */
 188 int of_pci_get_host_bridge_resources(struct device_node *dev,
 189                         unsigned char busno, unsigned char bus_max,
 190                         struct list_head *resources, resource_size_t *io_base)
 191 {
 192         struct resource_entry *window;
 193         struct resource *res;
 194         struct resource *bus_range;
 195         struct of_pci_range range;
 196         struct of_pci_range_parser parser;
 197         char range_type[4];
 198         int err;
 199
 200         if (io_base)
 201                 *io_base = (resource_size_t)OF_BAD_ADDR;
 202
 203         bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
 204         if (!bus_range)
 205                 return -ENOMEM;
 206
 207         pr_info("host bridge %s ranges:\n", dev->full_name);
 208
 209         err = of_pci_parse_bus_range(dev, bus_range);
 210         if (err) {
 211                 bus_range->start = busno;
 212                 bus_range->end = bus_max;
 213                 bus_range->flags = IORESOURCE_BUS;
 214                 pr_info("  No bus range found for %s, using %pR\n",
 215                         dev->full_name, bus_range);
 216         } else {
 217                 if (bus_range->end > bus_range->start + bus_max)
 218                         bus_range->end = bus_range->start + bus_max;
 219         }
 220         pci_add_resource(resources, bus_range);
 221
 222         /* Check for ranges property */
 223         err = of_pci_range_parser_init(&parser, dev);
 224         if (err)
 225                 goto parse_failed;
 226
 227         pr_debug("Parsing ranges property...\n");
 228         for_each_of_pci_range(&parser, &range) {
 229                 /* Read next ranges element */
 230                 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
 231                         snprintf(range_type, 4, " IO");
 232                 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
 233                         snprintf(range_type, 4, "MEM");
 234                 else
 235                         snprintf(range_type, 4, "err");
 236                 pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
 237                         range.cpu_addr, range.cpu_addr + range.size - 1,
 238                         range.pci_addr);
 239
 240                 /*
 241                  * If we failed translation or got a zero-sized region
 242                  * then skip this range
 243                  */
 244                 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 245                         continue;
 246
 247                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 248                 if (!res) {
 249                         err = -ENOMEM;
 250                         goto parse_failed;
 251                 }
 252
 253                 err = of_pci_range_to_resource(&range, dev, res);
 254                 if (err) {
 255                         kfree(res);
 256                         continue;
 257                 }
 258
 259                 if (resource_type(res) == IORESOURCE_IO) {
 260                         if (!io_base) {
 261                                 pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
 262                                         dev->full_name);
 263                                 err = -EINVAL;
 264                                 goto conversion_failed;
 265                         }
 266                         if (*io_base != (resource_size_t)OF_BAD_ADDR)
 267                                 pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
 268                                         dev->full_name);
 269                         *io_base = range.cpu_addr;
 270                 }
 271
 272                 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
 273         }
 274
 275         return 0;
 276
 277 conversion_failed:
 278         kfree(res);
 279 parse_failed:
 280         resource_list_for_each_entry(window, resources)
 281                 kfree(window->res);
 282         pci_free_resource_list(resources);
 283         return err;
 284 }
 285 EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
 286 #endif /* CONFIG_OF_ADDRESS */
 287
 288 /**
 289  * of_pci_map_rid - Translate a requester ID through a downstream mapping.
 290  * @np: root complex device node.
 291  * @rid: PCI requester ID to map.
 292  * @map_name: property name of the map to use.
 293  * @map_mask_name: optional property name of the mask to use.
 294  * @target: optional pointer to a target device node.
 295  * @id_out: optional pointer to receive the translated ID.
 296  *
 297  * Given a PCI requester ID, look up the appropriate implementation-defined
 298  * platform ID and/or the target device which receives transactions on that
 299  * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
 300  * @id_out may be NULL if only the other is required. If @target points to
 301  * a non-NULL device node pointer, only entries targeting that node will be
 302  * matched; if it points to a NULL value, it will receive the device node of
 303  * the first matching target phandle, with a reference held.
 304  *
 305  * Return: 0 on success or a standard error code on failure.
 306  */
 307 int of_pci_map_rid(struct device_node *np, u32 rid,
 308                    const char *map_name, const char *map_mask_name,
 309                    struct device_node **target, u32 *id_out)
 310 {
 311         u32 map_mask, masked_rid;
 312         int map_len;
 313         const __be32 *map = NULL;
 314
 315         if (!np || !map_name || (!target && !id_out))
 316                 return -EINVAL;
 317
 318         map = of_get_property(np, map_name, &map_len);
 319         if (!map) {
 320                 if (target)
 321                         return -ENODEV;
 322                 /* Otherwise, no map implies no translation */
 323                 *id_out = rid;
 324                 return 0;
 325         }
 326
 327         if (!map_len || map_len % (4 * sizeof(*map))) {
 328                 pr_err("%s: Error: Bad %s length: %d\n", np->full_name,
 329                         map_name, map_len);
 330                 return -EINVAL;
 331         }
 332
 333         /* The default is to select all bits. */
 334         map_mask = 0xffffffff;
 335
 336         /*
 337          * Can be overridden by "{iommu,msi}-map-mask" property.
 338          * If of_property_read_u32() fails, the default is used.
 339          */
 340         if (map_mask_name)
 341                 of_property_read_u32(np, map_mask_name, &map_mask);
 342
 343         masked_rid = map_mask & rid;
 344         for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
 345                 struct device_node *phandle_node;
 346                 u32 rid_base = be32_to_cpup(map + 0);
 347                 u32 phandle = be32_to_cpup(map + 1);
 348                 u32 out_base = be32_to_cpup(map + 2);
 349                 u32 rid_len = be32_to_cpup(map + 3);
 350
 351                 if (rid_base & ~map_mask) {
 352                         pr_err("%s: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
 353                                 np->full_name, map_name, map_name,
 354                                 map_mask, rid_base);
 355                         return -EFAULT;
 356                 }
 357
 358                 if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
 359                         continue;
 360
 361                 phandle_node = of_find_node_by_phandle(phandle);
 362                 if (!phandle_node)
 363                         return -ENODEV;
 364
 365                 if (target) {
 366                         if (*target)
 367                                 of_node_put(phandle_node);
 368                         else
 369                                 *target = phandle_node;
 370
 371                         if (*target != phandle_node)
 372                                 continue;
 373                 }
 374
 375                 if (id_out)
 376                         *id_out = masked_rid - rid_base + out_base;
 377
 378                 pr_debug("%s: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
 379                         np->full_name, map_name, map_mask, rid_base, out_base,
 380                         rid_len, rid, *id_out);
 381                 return 0;
 382         }
 383
 384         pr_err("%s: Invalid %s translation - no match for rid 0x%x on %s\n",
 385                 np->full_name, map_name, rid,
 386                 target && *target ? (*target)->full_name : "any target");
 387         return -EFAULT;
 388 }