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         u32 reg[5];
  61         int error;
  62
  63         error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
  64         if (error)
  65                 return error;
  66
  67         return (reg[0] >> 8) & 0xff;
  68 }
  69 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
  70
  71 /**
  72  * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
  73  * @node: device node
  74  * @res: address to a struct resource to return the bus-range
  75  *
  76  * Returns 0 on success or a negative error-code on failure.
  77  */
  78 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
  79 {
  80         u32 bus_range[2];
  81         int error;
  82
  83         error = of_property_read_u32_array(node, "bus-range", bus_range,
  84                                            ARRAY_SIZE(bus_range));
  85         if (error)
  86                 return error;
  87
  88         res->name = node->name;
  89         res->start = bus_range[0];
  90         res->end = bus_range[1];
  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         u32 domain;
 109         int error;
 110
 111         error = of_property_read_u32(node, "linux,pci-domain", &domain);
 112         if (error)
 113                 return error;
 114
 115         return (u16)domain;
 116 }
 117 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
 118
 119 /**
 120  * This function will try to find the limitation of link speed by finding
 121  * a property called "max-link-speed" of the given device node.
 122  *
 123  * @node: device tree node with the max link speed information
 124  *
 125  * Returns the associated max link speed from DT, or a negative value if the
 126  * required property is not found or is invalid.
 127  */
 128 int of_pci_get_max_link_speed(struct device_node *node)
 129 {
 130         u32 max_link_speed;
 131
 132         if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
 133             max_link_speed > 4)
 134                 return -EINVAL;
 135
 136         return max_link_speed;
 137 }
 138 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
 139
 140 /**
 141  * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
 142  *                           is present and valid
 143  */
 144 void of_pci_check_probe_only(void)
 145 {
 146         u32 val;
 147         int ret;
 148
 149         ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
 150         if (ret) {
 151                 if (ret == -ENODATA || ret == -EOVERFLOW)
 152                         pr_warn("linux,pci-probe-only without valid value, ignoring\n");
 153                 return;
 154         }
 155
 156         if (val)
 157                 pci_add_flags(PCI_PROBE_ONLY);
 158         else
 159                 pci_clear_flags(PCI_PROBE_ONLY);
 160
 161         pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
 162 }
 163 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
 164
 165 #if defined(CONFIG_OF_ADDRESS)
 166 /**
 167  * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
 168  * @dev: device node of the host bridge having the range property
 169  * @busno: bus number associated with the bridge root bus
 170  * @bus_max: maximum number of buses for this bridge
 171  * @resources: list where the range of resources will be added after DT parsing
 172  * @io_base: pointer to a variable that will contain on return the physical
 173  * address for the start of the I/O range. Can be NULL if the caller doesn't
 174  * expect IO ranges to be present in the device tree.
 175  *
 176  * It is the caller's job to free the @resources list.
 177  *
 178  * This function will parse the "ranges" property of a PCI host bridge device
 179  * node and setup the resource mapping based on its content. It is expected
 180  * that the property conforms with the Power ePAPR document.
 181  *
 182  * It returns zero if the range parsing has been successful or a standard error
 183  * value if it failed.
 184  */
 185 int of_pci_get_host_bridge_resources(struct device_node *dev,
 186                         unsigned char busno, unsigned char bus_max,
 187                         struct list_head *resources, resource_size_t *io_base)
 188 {
 189         struct resource_entry *window;
 190         struct resource *res;
 191         struct resource *bus_range;
 192         struct of_pci_range range;
 193         struct of_pci_range_parser parser;
 194         char range_type[4];
 195         int err;
 196
 197         if (io_base)
 198                 *io_base = (resource_size_t)OF_BAD_ADDR;
 199
 200         bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
 201         if (!bus_range)
 202                 return -ENOMEM;
 203
 204         pr_info("host bridge %pOF ranges:\n", dev);
 205
 206         err = of_pci_parse_bus_range(dev, bus_range);
 207         if (err) {
 208                 bus_range->start = busno;
 209                 bus_range->end = bus_max;
 210                 bus_range->flags = IORESOURCE_BUS;
 211                 pr_info("  No bus range found for %pOF, using %pR\n",
 212                         dev, bus_range);
 213         } else {
 214                 if (bus_range->end > bus_range->start + bus_max)
 215                         bus_range->end = bus_range->start + bus_max;
 216         }
 217         pci_add_resource(resources, bus_range);
 218
 219         /* Check for ranges property */
 220         err = of_pci_range_parser_init(&parser, dev);
 221         if (err)
 222                 goto parse_failed;
 223
 224         pr_debug("Parsing ranges property...\n");
 225         for_each_of_pci_range(&parser, &range) {
 226                 /* Read next ranges element */
 227                 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
 228                         snprintf(range_type, 4, " IO");
 229                 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
 230                         snprintf(range_type, 4, "MEM");
 231                 else
 232                         snprintf(range_type, 4, "err");
 233                 pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
 234                         range.cpu_addr, range.cpu_addr + range.size - 1,
 235                         range.pci_addr);
 236
 237                 /*
 238                  * If we failed translation or got a zero-sized region
 239                  * then skip this range
 240                  */
 241                 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 242                         continue;
 243
 244                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 245                 if (!res) {
 246                         err = -ENOMEM;
 247                         goto parse_failed;
 248                 }
 249
 250                 err = of_pci_range_to_resource(&range, dev, res);
 251                 if (err) {
 252                         kfree(res);
 253                         continue;
 254                 }
 255
 256                 if (resource_type(res) == IORESOURCE_IO) {
 257                         if (!io_base) {
 258                                 pr_err("I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
 259                                         dev);
 260                                 err = -EINVAL;
 261                                 goto conversion_failed;
 262                         }
 263                         if (*io_base != (resource_size_t)OF_BAD_ADDR)
 264                                 pr_warn("More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
 265                                         dev);
 266                         *io_base = range.cpu_addr;
 267                 }
 268
 269                 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
 270         }
 271
 272         return 0;
 273
 274 conversion_failed:
 275         kfree(res);
 276 parse_failed:
 277         resource_list_for_each_entry(window, resources)
 278                 kfree(window->res);
 279         pci_free_resource_list(resources);
 280         return err;
 281 }
 282 EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
 283 #endif /* CONFIG_OF_ADDRESS */
 284
 285 /**
 286  * of_pci_map_rid - Translate a requester ID through a downstream mapping.
 287  * @np: root complex device node.
 288  * @rid: PCI requester ID to map.
 289  * @map_name: property name of the map to use.
 290  * @map_mask_name: optional property name of the mask to use.
 291  * @target: optional pointer to a target device node.
 292  * @id_out: optional pointer to receive the translated ID.
 293  *
 294  * Given a PCI requester ID, look up the appropriate implementation-defined
 295  * platform ID and/or the target device which receives transactions on that
 296  * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
 297  * @id_out may be NULL if only the other is required. If @target points to
 298  * a non-NULL device node pointer, only entries targeting that node will be
 299  * matched; if it points to a NULL value, it will receive the device node of
 300  * the first matching target phandle, with a reference held.
 301  *
 302  * Return: 0 on success or a standard error code on failure.
 303  */
 304 int of_pci_map_rid(struct device_node *np, u32 rid,
 305                    const char *map_name, const char *map_mask_name,
 306                    struct device_node **target, u32 *id_out)
 307 {
 308         u32 map_mask, masked_rid;
 309         int map_len;
 310         const __be32 *map = NULL;
 311
 312         if (!np || !map_name || (!target && !id_out))
 313                 return -EINVAL;
 314
 315         map = of_get_property(np, map_name, &map_len);
 316         if (!map) {
 317                 if (target)
 318                         return -ENODEV;
 319                 /* Otherwise, no map implies no translation */
 320                 *id_out = rid;
 321                 return 0;
 322         }
 323
 324         if (!map_len || map_len % (4 * sizeof(*map))) {
 325                 pr_err("%pOF: Error: Bad %s length: %d\n", np,
 326                         map_name, map_len);
 327                 return -EINVAL;
 328         }
 329
 330         /* The default is to select all bits. */
 331         map_mask = 0xffffffff;
 332
 333         /*
 334          * Can be overridden by "{iommu,msi}-map-mask" property.
 335          * If of_property_read_u32() fails, the default is used.
 336          */
 337         if (map_mask_name)
 338                 of_property_read_u32(np, map_mask_name, &map_mask);
 339
 340         masked_rid = map_mask & rid;
 341         for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
 342                 struct device_node *phandle_node;
 343                 u32 rid_base = be32_to_cpup(map + 0);
 344                 u32 phandle = be32_to_cpup(map + 1);
 345                 u32 out_base = be32_to_cpup(map + 2);
 346                 u32 rid_len = be32_to_cpup(map + 3);
 347
 348                 if (rid_base & ~map_mask) {
 349                         pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
 350                                 np, map_name, map_name,
 351                                 map_mask, rid_base);
 352                         return -EFAULT;
 353                 }
 354
 355                 if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
 356                         continue;
 357
 358                 phandle_node = of_find_node_by_phandle(phandle);
 359                 if (!phandle_node)
 360                         return -ENODEV;
 361
 362                 if (target) {
 363                         if (*target)
 364                                 of_node_put(phandle_node);
 365                         else
 366                                 *target = phandle_node;
 367
 368                         if (*target != phandle_node)
 369                                 continue;
 370                 }
 371
 372                 if (id_out)
 373                         *id_out = masked_rid - rid_base + out_base;
 374
 375                 pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
 376                         np, map_name, map_mask, rid_base, out_base,
 377                         rid_len, rid, *id_out);
 378                 return 0;
 379         }
 380
 381         pr_err("%pOF: Invalid %s translation - no match for rid 0x%x on %pOF\n",
 382                 np, map_name, rid, target && *target ? *target : NULL);
 383         return -EFAULT;
 384 }