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_dma_configure - Setup DMA configuration
 122  * @dev: ptr to pci_dev struct of the PCI device
 123  *
 124  * Function to update PCI devices's DMA configuration using the same
 125  * info from the OF node of host bridge's parent (if any).
 126  */
 127 void of_pci_dma_configure(struct pci_dev *pci_dev)
 128 {
 129         struct device *dev = &pci_dev->dev;
 130         struct device *bridge = pci_get_host_bridge_device(pci_dev);
 131
 132         if (!bridge->parent)
 133                 return;
 134
 135         of_dma_configure(dev, bridge->parent->of_node);
 136         pci_put_host_bridge_device(bridge);
 137 }
 138 EXPORT_SYMBOL_GPL(of_pci_dma_configure);
 139
 140 #if defined(CONFIG_OF_ADDRESS)
 141 /**
 142  * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
 143  * @dev: device node of the host bridge having the range property
 144  * @busno: bus number associated with the bridge root bus
 145  * @bus_max: maximum number of buses for this bridge
 146  * @resources: list where the range of resources will be added after DT parsing
 147  * @io_base: pointer to a variable that will contain on return the physical
 148  * address for the start of the I/O range. Can be NULL if the caller doesn't
 149  * expect IO ranges to be present in the device tree.
 150  *
 151  * It is the caller's job to free the @resources list.
 152  *
 153  * This function will parse the "ranges" property of a PCI host bridge device
 154  * node and setup the resource mapping based on its content. It is expected
 155  * that the property conforms with the Power ePAPR document.
 156  *
 157  * It returns zero if the range parsing has been successful or a standard error
 158  * value if it failed.
 159  */
 160 int of_pci_get_host_bridge_resources(struct device_node *dev,
 161                         unsigned char busno, unsigned char bus_max,
 162                         struct list_head *resources, resource_size_t *io_base)
 163 {
 164         struct resource_entry *window;
 165         struct resource *res;
 166         struct resource *bus_range;
 167         struct of_pci_range range;
 168         struct of_pci_range_parser parser;
 169         char range_type[4];
 170         int err;
 171
 172         if (io_base)
 173                 *io_base = (resource_size_t)OF_BAD_ADDR;
 174
 175         bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
 176         if (!bus_range)
 177                 return -ENOMEM;
 178
 179         pr_info("PCI host bridge %s ranges:\n", dev->full_name);
 180
 181         err = of_pci_parse_bus_range(dev, bus_range);
 182         if (err) {
 183                 bus_range->start = busno;
 184                 bus_range->end = bus_max;
 185                 bus_range->flags = IORESOURCE_BUS;
 186                 pr_info("  No bus range found for %s, using %pR\n",
 187                         dev->full_name, bus_range);
 188         } else {
 189                 if (bus_range->end > bus_range->start + bus_max)
 190                         bus_range->end = bus_range->start + bus_max;
 191         }
 192         pci_add_resource(resources, bus_range);
 193
 194         /* Check for ranges property */
 195         err = of_pci_range_parser_init(&parser, dev);
 196         if (err)
 197                 goto parse_failed;
 198
 199         pr_debug("Parsing ranges property...\n");
 200         for_each_of_pci_range(&parser, &range) {
 201                 /* Read next ranges element */
 202                 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
 203                         snprintf(range_type, 4, " IO");
 204                 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
 205                         snprintf(range_type, 4, "MEM");
 206                 else
 207                         snprintf(range_type, 4, "err");
 208                 pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
 209                         range.cpu_addr, range.cpu_addr + range.size - 1,
 210                         range.pci_addr);
 211
 212                 /*
 213                  * If we failed translation or got a zero-sized region
 214                  * then skip this range
 215                  */
 216                 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 217                         continue;
 218
 219                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 220                 if (!res) {
 221                         err = -ENOMEM;
 222                         goto parse_failed;
 223                 }
 224
 225                 err = of_pci_range_to_resource(&range, dev, res);
 226                 if (err)
 227                         goto conversion_failed;
 228
 229                 if (resource_type(res) == IORESOURCE_IO) {
 230                         if (!io_base) {
 231                                 pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
 232                                         dev->full_name);
 233                                 err = -EINVAL;
 234                                 goto conversion_failed;
 235                         }
 236                         if (*io_base != (resource_size_t)OF_BAD_ADDR)
 237                                 pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
 238                                         dev->full_name);
 239                         *io_base = range.cpu_addr;
 240                 }
 241
 242                 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
 243         }
 244
 245         return 0;
 246
 247 conversion_failed:
 248         kfree(res);
 249 parse_failed:
 250         resource_list_for_each_entry(window, resources)
 251                 kfree(window->res);
 252         pci_free_resource_list(resources);
 253         return err;
 254 }
 255 EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
 256 #endif /* CONFIG_OF_ADDRESS */
 257
 258 #ifdef CONFIG_PCI_MSI
 259
 260 static LIST_HEAD(of_pci_msi_chip_list);
 261 static DEFINE_MUTEX(of_pci_msi_chip_mutex);
 262
 263 int of_pci_msi_chip_add(struct msi_controller *chip)
 264 {
 265         if (!of_property_read_bool(chip->of_node, "msi-controller"))
 266                 return -EINVAL;
 267
 268         mutex_lock(&of_pci_msi_chip_mutex);
 269         list_add(&chip->list, &of_pci_msi_chip_list);
 270         mutex_unlock(&of_pci_msi_chip_mutex);
 271
 272         return 0;
 273 }
 274 EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);
 275
 276 void of_pci_msi_chip_remove(struct msi_controller *chip)
 277 {
 278         mutex_lock(&of_pci_msi_chip_mutex);
 279         list_del(&chip->list);
 280         mutex_unlock(&of_pci_msi_chip_mutex);
 281 }
 282 EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);
 283
 284 struct msi_controller *of_pci_find_msi_chip_by_node(struct device_node *of_node)
 285 {
 286         struct msi_controller *c;
 287
 288         mutex_lock(&of_pci_msi_chip_mutex);
 289         list_for_each_entry(c, &of_pci_msi_chip_list, list) {
 290                 if (c->of_node == of_node) {
 291                         mutex_unlock(&of_pci_msi_chip_mutex);
 292                         return c;
 293                 }
 294         }
 295         mutex_unlock(&of_pci_msi_chip_mutex);
 296
 297         return NULL;
 298 }
 299 EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);
 300
 301 #endif /* CONFIG_PCI_MSI */