2 * (c) 1999--2000 Martin Mares <mj@suse.cz>
3 * (c) 2003 Eric Biederman <ebiederm@xmission.com>
4 * (c) 2003 Linux Networx
6 /* lots of mods by ron minnich (rminnich@lanl.gov), with
7 * the final architecture guidance from Tom Merritt (tjm@codegen.com)
8 * In particular, we changed from the one-pass original version to
9 * Tom's recommended multiple-pass version. I wasn't sure about doing
10 * it with multiple passes, until I actually started doing it and saw
11 * the wisdom of Tom's recommendations ...
13 * Lots of cleanups by Eric Biederman to handle bridges, and to
14 * handle resource allocation for non-pci devices.
17 #include <console/console.h>
20 #include <device/device.h>
21 #include <device/pci.h>
22 #include <device/pci_ids.h>
26 /** Linked list of ALL devices */
27 struct device *all_devices = &dev_root;
28 /** Pointer to the last device */
29 static struct device **last_dev_p = &dev_root.next;
31 /** The upper limit of MEM resource of the devices.
32 * Reserve 20M for the system */
33 #define DEVICE_MEM_HIGH 0xFEC00000UL
34 /** The lower limit of IO resource of the devices.
35 * Reserve 4k for ISA/Legacy devices */
36 #define DEVICE_IO_START 0x1000
39 * @brief Allocate a new device structure.
41 * Allocte a new device structure and attached it to the device tree as a
42 * child of the parent bus.
44 * @param parent parent bus the newly created device attached to.
45 * @param path path to the device to be created.
47 * @return pointer to the newly created device structure.
51 device_t alloc_dev(struct bus *parent, struct device_path *path)
56 /* Find the last child of our parent */
57 for(child = parent->children; child && child->sibling; ) {
58 child = child->sibling;
60 dev = malloc(sizeof(*dev));
62 die("DEV: out of memory.\n");
64 memset(dev, 0, sizeof(*dev));
65 memcpy(&dev->path, path, sizeof(*path));
67 /* Append a new device to the global device list.
68 * The list is used to find devices once everything is set up.
71 last_dev_p = &dev->next;
73 /* Initialize the back pointers in the link fields */
74 for(link = 0; link < MAX_LINKS; link++) {
75 dev->link[link].dev = dev;
76 dev->link[link].link = link;
79 /* Add the new device to the list of children of the bus. */
84 parent->children = dev;
86 /* If we don't have any other information about a device enable it */
93 * @brief round a number up to an alignment.
94 * @param val the starting value
95 * @param roundup Alignment as a power of two
96 * @returns rounded up number
98 static unsigned long round(unsigned long val, unsigned long roundup)
100 /* ROUNDUP MUST BE A POWER OF TWO. */
101 unsigned long inverse;
102 inverse = ~(roundup - 1);
103 val += (roundup - 1);
108 static unsigned long round_down(unsigned long val, unsigned long round_down)
110 /* ROUND_DOWN MUST BE A POWER OF TWO. */
111 unsigned long inverse;
112 inverse = ~(round_down - 1);
118 /** Read the resources on all devices of a given bus.
119 * @param bus bus to read the resources on.
121 static void read_resources(struct bus *bus)
123 struct device *curdev;
125 /* Walk through all of the devices and find which resources they need. */
126 for(curdev = bus->children; curdev; curdev = curdev->sibling) {
129 if (curdev->resources > 0) {
132 if (!curdev->ops || !curdev->ops->read_resources) {
133 printk_err("%s missing read_resources\n",
137 if (!curdev->enabled) {
140 curdev->ops->read_resources(curdev);
141 /* Read in subtractive resources behind the current device */
143 for(i = 0; i < curdev->resources; i++) {
144 struct resource *resource;
145 resource = &curdev->resource[i];
146 if ((resource->flags & IORESOURCE_SUBTRACTIVE) &&
147 (!(links & (1 << resource->index))))
149 links |= (1 << resource->index);
150 read_resources(&curdev->link[resource->index]);
157 struct pick_largest_state {
158 struct resource *last;
159 struct device *result_dev;
160 struct resource *result;
164 static void pick_largest_resource(struct pick_largest_state *state,
165 struct device *dev, struct resource *resource)
167 struct resource *last;
169 /* Be certain to pick the successor to last */
170 if (resource == last) {
171 state->seen_last = 1;
175 (last->align < resource->align) ||
176 ((last->align == resource->align) &&
177 (last->size < resource->size)) ||
178 ((last->align == resource->align) &&
179 (last->size == resource->size) &&
180 (!state->seen_last)))) {
183 if (!state->result ||
184 (state->result->align < resource->align) ||
185 ((state->result->align == resource->align) &&
186 (state->result->size < resource->size))) {
187 state->result_dev = dev;
188 state->result = resource;
192 static void find_largest_resource(struct pick_largest_state *state,
193 struct bus *bus, unsigned long type_mask, unsigned long type)
195 struct device *curdev;
196 for(curdev = bus->children; curdev; curdev = curdev->sibling) {
198 for(i = 0; i < curdev->resources; i++) {
199 struct resource *resource = &curdev->resource[i];
200 /* If it isn't the right kind of resource ignore it */
201 if ((resource->flags & type_mask) != type) {
204 /* If it is a subtractive resource recurse */
205 if (resource->flags & IORESOURCE_SUBTRACTIVE) {
207 subbus = &curdev->link[resource->index];
208 find_largest_resource(state, subbus, type_mask, type);
211 /* See if this is the largest resource */
212 pick_largest_resource(state, curdev, resource);
217 static struct device *largest_resource(struct bus *bus,
218 struct resource **result_res,
219 unsigned long type_mask,
222 struct pick_largest_state state;
224 state.last = *result_res;
225 state.result_dev = 0;
229 find_largest_resource(&state, bus, type_mask, type);
231 *result_res = state.result;
232 return state.result_dev;
235 /* Compute allocate resources is the guts of the resource allocator.
238 * - Allocate resources locations for every device.
239 * - Don't overlap, and follow the rules of bridges.
240 * - Don't overlap with resources in fixed locations.
241 * - Be efficient so we don't have ugly strategies.
244 * - Devices that have fixed addresses are the minority so don't
245 * worry about them too much. Instead only use part of the address
246 * space for devices with programmable addresses. This easily handles
247 * everything except bridges.
249 * - PCI devices are required to have thier sizes and their alignments
250 * equal. In this case an optimal solution to the packing problem
251 * exists. Allocate all devices from highest alignment to least
252 * alignment or vice versa. Use this.
254 * - So we can handle more than PCI run two allocation passes on
255 * bridges. The first to see how large the resources are behind
256 * the bridge, and what their alignment requirements are. The
257 * second to assign a safe address to the devices behind the
258 * bridge. This allows me to treat a bridge as just a device with
259 * a couple of resources, and not need to special case it in the
260 * allocator. Also this allows handling of other types of bridges.
264 void compute_allocate_resource(
266 struct resource *bridge,
267 unsigned long type_mask,
271 struct resource *resource;
273 unsigned long align, min_align;
277 printk_spew("%s compute_allocate_%s: base: %08lx size: %08lx align: %d gran: %d\n",
279 (bridge->flags & IORESOURCE_IO)? "io":
280 (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
281 base, bridge->size, bridge->align, bridge->gran);
284 /* We want different minimum alignments for different kinds of
285 * resources. These minimums are not device type specific
286 * but resource type specific.
288 if (bridge->flags & IORESOURCE_IO) {
289 min_align = log2(DEVICE_IO_ALIGN);
291 if (bridge->flags & IORESOURCE_MEM) {
292 min_align = log2(DEVICE_MEM_ALIGN);
295 /* Make certain I have read in all of the resources */
298 /* Remember I haven't found anything yet. */
301 /* Walk through all the devices on the current bus and
302 * compute the addresses.
304 while((dev = largest_resource(bus, &resource, type_mask, type))) {
306 /* Do NOT I repeat do not ignore resources which have zero size.
307 * If they need to be ignored dev->read_resources should not even
308 * return them. Some resources must be set even when they have
309 * no size. PCI bridge resources are a good example of this.
312 /* Propogate the resource alignment to the bridge register */
313 if (resource->align > bridge->align) {
314 bridge->align = resource->align;
317 /* Make certain we are dealing with a good minimum size */
318 size = resource->size;
319 align = resource->align;
320 if (align < min_align) {
323 if (resource->flags & IORESOURCE_FIXED) {
326 if (resource->flags & IORESOURCE_IO) {
327 /* Don't allow potential aliases over the
328 * legacy pci expansion card addresses.
329 * The legacy pci decodes only 10 bits,
330 * uses 100h - 3ffh. Therefor, only 0 - ff
331 * can be used out of each 400h block of io
334 if ((base & 0x300) != 0) {
335 base = (base & ~0x3ff) + 0x400;
337 /* Don't allow allocations in the VGA IO range.
338 * PCI has special cases for that.
340 else if ((base >= 0x3b0) && (base <= 0x3df)) {
344 if (((round(base, 1UL << align) + size) -1) <= resource->limit) {
345 /* base must be aligned to size */
346 base = round(base, 1UL << align);
347 resource->base = base;
348 resource->flags |= IORESOURCE_ASSIGNED;
349 resource->flags &= ~IORESOURCE_STORED;
353 "%s %02x * [0x%08lx - 0x%08lx] %s\n",
356 resource->base, resource->base + resource->size - 1,
357 (resource->flags & IORESOURCE_IO)? "io":
358 (resource->flags & IORESOURCE_PREFETCH)? "prefmem": "mem");
361 /* A pci bridge resource does not need to be a power
362 * of two size, but it does have a minimum granularity.
363 * Round the size up to that minimum granularity so we
364 * know not to place something else at an address postitively
365 * decoded by the bridge.
367 bridge->size = round(base, 1UL << bridge->gran) - bridge->base;
369 printk_spew("%s compute_allocate_%s: base: %08lx size: %08lx align: %d gran: %d done\n",
371 (bridge->flags & IORESOURCE_IO)? "io":
372 (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
373 base, bridge->size, bridge->align, bridge->gran);
378 static void allocate_vga_resource(void)
380 #warning "FIXME modify allocate_vga_resource so it is less pci centric!"
381 #warning "This function knows to much about PCI stuff, it should be just a ietrator/visitor."
383 /* FIXME handle the VGA pallette snooping */
384 struct device *dev, *vga;
388 for(dev = all_devices; dev; dev = dev->next) {
389 if (((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) &&
390 ((dev->class >> 8) != PCI_CLASS_DISPLAY_OTHER)) {
392 printk_debug("Allocating VGA resource %s\n",
397 /* All legacy VGA cards have MEM & I/O space registers */
398 dev->command |= PCI_COMMAND_MEMORY | PCI_COMMAND_IO;
400 /* It isn't safe to enable other VGA cards */
401 dev->command &= ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
408 /* Now walk up the bridges setting the VGA enable */
410 bus->bridge_ctrl |= PCI_BRIDGE_CTL_VGA;
411 bus = (bus == bus->dev->bus)? 0 : bus->dev->bus;
416 /** Assign the computed resources to the bridges and devices on the bus.
417 * Recurse to any bridges found on this bus first. Then do the devices
420 * @param bus Pointer to the structure for this bus
422 void assign_resources(struct bus *bus)
424 struct device *curdev;
426 printk_debug("ASSIGN RESOURCES, bus %d\n", bus->secondary);
428 for (curdev = bus->children; curdev; curdev = curdev->sibling) {
429 if (!curdev->ops || !curdev->ops->set_resources) {
430 printk_err("%s missing set_resources\n",
434 if (!curdev->enabled) {
437 curdev->ops->set_resources(curdev);
439 printk_debug("ASSIGNED RESOURCES, bus %d\n", bus->secondary);
443 * @brief Enable the resources for a specific device
445 * @param dev the device whose resources are to be enabled
447 * Enable resources of the device by calling the device specific
448 * enable_resources() method.
450 * The parent's resources should be enabled first to avoid having enabling
451 * order problem. This is done by calling the parent's enable_resources()
452 * method and let that method to call it's children's enable_resoruces() via
453 * enable_childrens_resources().
455 * Indirect mutual recursion:
457 void enable_resources(struct device *dev)
459 if (!dev->ops || !dev->ops->enable_resources) {
460 printk_err("%s missing enable_resources\n", dev_path(dev));
466 dev->ops->enable_resources(dev);
470 * @brief Determine the existence of dynamic devices and construct dynamic
473 * Start from the root device 'dev_root', scan the buses in the system
474 * recursively, build the dynamic device tree according to the result
477 * This function has no idea how to scan and probe buses and devices at all.
478 * It depends on the bus/device specific scan_bus() method to do it. The
479 * scan_bus() function also has to create the device structure and attach
480 * it to the device tree.
482 void dev_enumerate(void)
485 unsigned subordinate;
486 printk_info("Enumerating buses...\n");
488 if (!root->ops || !root->ops->scan_bus) {
489 printk_err("dev_root missing scan_bus operation");
492 subordinate = root->ops->scan_bus(root, 0);
493 printk_info("done\n");
497 * @brief Configure devices on the devices tree.
499 * Starting at the root of the dynamic device tree, travel recursively,
500 * compute resources needed by each device and allocate them.
502 * I/O resources start at DEVICE_IO_START and grow upward. MEM resources start
503 * at DEVICE_MEM_START and grow downward.
505 * Since the assignment is hierarchical we set the values into the dev_root
508 void dev_configure(void)
512 printk_info("Allocating resources...\n");
515 if (!root->ops || !root->ops->read_resources) {
516 printk_err("dev_root missing read_resources\n");
519 if (!root->ops || !root->ops->set_resources) {
520 printk_err("dev_root missing set_resources\n");
523 root->ops->read_resources(root);
525 /* Make certain the io devices are allocated somewhere safe. */
526 root->resource[0].base = DEVICE_IO_START;
527 root->resource[0].flags |= IORESOURCE_ASSIGNED;
528 root->resource[0].flags &= ~IORESOURCE_STORED;
529 /* Now reallocate the pci resources memory with the
530 * highest addresses I can manage.
532 root->resource[1].base =
533 round_down(DEVICE_MEM_HIGH - root->resource[1].size,
534 1UL << root->resource[1].align);
535 root->resource[1].flags |= IORESOURCE_ASSIGNED;
536 root->resource[1].flags &= ~IORESOURCE_STORED;
538 /* Allocate the VGA I/O resource.. */
539 allocate_vga_resource();
541 /* Store the computed resource allocations into device registers ... */
542 root->ops->set_resources(root);
544 printk_info("done.\n");
548 * @brief Enable devices on the device tree.
550 * Starting at the root, walk the tree and enable all devices/bridges by
551 * calling the device's enable_resources() method.
553 void dev_enable(void)
555 printk_info("Enabling resourcess...\n");
557 /* now enable everything. */
558 enable_resources(&dev_root);
560 printk_info("done.\n");
564 * @brief Initialize all devices in the global device list.
566 * Starting at the first device on the global device link list,
567 * walk the list and call a driver to do device specific setup.
569 void dev_initialize(void)
573 printk_info("Initializing devices...\n");
574 for (dev = all_devices; dev; dev = dev->next) {
575 if (dev->enabled && dev->ops && dev->ops->init) {
576 printk_debug("%s init\n", dev_path(dev));
580 printk_info("Devices initialized\n");