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  * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
 124  *                           is present and valid
 125  */
 126 void of_pci_check_probe_only(void)
 127 {
 128         u32 val;
 129         int ret;
 130
 131         ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
 132         if (ret) {
 133                 if (ret == -ENODATA || ret == -EOVERFLOW)
 134                         pr_warn("linux,pci-probe-only without valid value, ignoring\n");
 135                 return;
 136         }
 137
 138         if (val)
 139                 pci_add_flags(PCI_PROBE_ONLY);
 140         else
 141                 pci_clear_flags(PCI_PROBE_ONLY);
 142
 143         pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
 144 }
 145 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
 146
 147 #if defined(CONFIG_OF_ADDRESS)
 148 /**
 149  * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
 150  * @dev: device node of the host bridge having the range property
 151  * @busno: bus number associated with the bridge root bus
 152  * @bus_max: maximum number of buses for this bridge
 153  * @resources: list where the range of resources will be added after DT parsing
 154  * @io_base: pointer to a variable that will contain on return the physical
 155  * address for the start of the I/O range. Can be NULL if the caller doesn't
 156  * expect IO ranges to be present in the device tree.
 157  *
 158  * It is the caller's job to free the @resources list.
 159  *
 160  * This function will parse the "ranges" property of a PCI host bridge device
 161  * node and setup the resource mapping based on its content. It is expected
 162  * that the property conforms with the Power ePAPR document.
 163  *
 164  * It returns zero if the range parsing has been successful or a standard error
 165  * value if it failed.
 166  */
 167 int of_pci_get_host_bridge_resources(struct device_node *dev,
 168                         unsigned char busno, unsigned char bus_max,
 169                         struct list_head *resources, resource_size_t *io_base)
 170 {
 171         struct resource_entry *window;
 172         struct resource *res;
 173         struct resource *bus_range;
 174         struct of_pci_range range;
 175         struct of_pci_range_parser parser;
 176         char range_type[4];
 177         int err;
 178
 179         if (io_base)
 180                 *io_base = (resource_size_t)OF_BAD_ADDR;
 181
 182         bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
 183         if (!bus_range)
 184                 return -ENOMEM;
 185
 186         pr_info("host bridge %s ranges:\n", dev->full_name);
 187
 188         err = of_pci_parse_bus_range(dev, bus_range);
 189         if (err) {
 190                 bus_range->start = busno;
 191                 bus_range->end = bus_max;
 192                 bus_range->flags = IORESOURCE_BUS;
 193                 pr_info("  No bus range found for %s, using %pR\n",
 194                         dev->full_name, bus_range);
 195         } else {
 196                 if (bus_range->end > bus_range->start + bus_max)
 197                         bus_range->end = bus_range->start + bus_max;
 198         }
 199         pci_add_resource(resources, bus_range);
 200
 201         /* Check for ranges property */
 202         err = of_pci_range_parser_init(&parser, dev);
 203         if (err)
 204                 goto parse_failed;
 205
 206         pr_debug("Parsing ranges property...\n");
 207         for_each_of_pci_range(&parser, &range) {
 208                 /* Read next ranges element */
 209                 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
 210                         snprintf(range_type, 4, " IO");
 211                 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
 212                         snprintf(range_type, 4, "MEM");
 213                 else
 214                         snprintf(range_type, 4, "err");
 215                 pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
 216                         range.cpu_addr, range.cpu_addr + range.size - 1,
 217                         range.pci_addr);
 218
 219                 /*
 220                  * If we failed translation or got a zero-sized region
 221                  * then skip this range
 222                  */
 223                 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 224                         continue;
 225
 226                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 227                 if (!res) {
 228                         err = -ENOMEM;
 229                         goto parse_failed;
 230                 }
 231
 232                 err = of_pci_range_to_resource(&range, dev, res);
 233                 if (err) {
 234                         kfree(res);
 235                         continue;
 236                 }
 237
 238                 if (resource_type(res) == IORESOURCE_IO) {
 239                         if (!io_base) {
 240                                 pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
 241                                         dev->full_name);
 242                                 err = -EINVAL;
 243                                 goto conversion_failed;
 244                         }
 245                         if (*io_base != (resource_size_t)OF_BAD_ADDR)
 246                                 pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
 247                                         dev->full_name);
 248                         *io_base = range.cpu_addr;
 249                 }
 250
 251                 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
 252         }
 253
 254         return 0;
 255
 256 conversion_failed:
 257         kfree(res);
 258 parse_failed:
 259         resource_list_for_each_entry(window, resources)
 260                 kfree(window->res);
 261         pci_free_resource_list(resources);
 262         return err;
 263 }
 264 EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
 265 #endif /* CONFIG_OF_ADDRESS */
 266
 267 #ifdef CONFIG_PCI_MSI
 268
 269 static LIST_HEAD(of_pci_msi_chip_list);
 270 static DEFINE_MUTEX(of_pci_msi_chip_mutex);
 271
 272 int of_pci_msi_chip_add(struct msi_controller *chip)
 273 {
 274         if (!of_property_read_bool(chip->of_node, "msi-controller"))
 275                 return -EINVAL;
 276
 277         mutex_lock(&of_pci_msi_chip_mutex);
 278         list_add(&chip->list, &of_pci_msi_chip_list);
 279         mutex_unlock(&of_pci_msi_chip_mutex);
 280
 281         return 0;
 282 }
 283 EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);
 284
 285 void of_pci_msi_chip_remove(struct msi_controller *chip)
 286 {
 287         mutex_lock(&of_pci_msi_chip_mutex);
 288         list_del(&chip->list);
 289         mutex_unlock(&of_pci_msi_chip_mutex);
 290 }
 291 EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);
 292
 293 struct msi_controller *of_pci_find_msi_chip_by_node(struct device_node *of_node)
 294 {
 295         struct msi_controller *c;
 296
 297         mutex_lock(&of_pci_msi_chip_mutex);
 298         list_for_each_entry(c, &of_pci_msi_chip_list, list) {
 299                 if (c->of_node == of_node) {
 300                         mutex_unlock(&of_pci_msi_chip_mutex);
 301                         return c;
 302                 }
 303         }
 304         mutex_unlock(&of_pci_msi_chip_mutex);
 305
 306         return NULL;
 307 }
 308 EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);
 309
 310 #endif /* CONFIG_PCI_MSI */