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
__of_pci_pci_compare(struct device_node * node,unsigned int data)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
of_pci_find_child_device(struct device_node * parent,unsigned int devfn)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 */
of_pci_get_devfn(struct device_node * np)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 */
of_pci_parse_bus_range(struct device_node * node,struct resource * res)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 */
of_get_pci_domain_nr(struct device_node * node)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 */
of_pci_check_probe_only(void)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 */
of_pci_get_host_bridge_resources(struct device_node * dev,unsigned char busno,unsigned char bus_max,struct list_head * resources,resource_size_t * io_base)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
of_pci_msi_chip_add(struct msi_controller * chip)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
of_pci_msi_chip_remove(struct msi_controller * chip)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
of_pci_find_msi_chip_by_node(struct device_node * of_node)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 */
310