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