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;
61 dev = malloc(sizeof(*dev));
63 die("DEV: out of memory.\n");
65 memset(dev, 0, sizeof(*dev));
66 memcpy(&dev->path, path, sizeof(*path));
68 /* Append a new device to the global device list.
69 * The list is used to find devices once everything is set up.
72 last_dev_p = &dev->next;
74 /* Initialize the back pointers in the link fields */
75 for (link = 0; link < MAX_LINKS; link++) {
76 dev->link[link].dev = dev;
77 dev->link[link].link = link;
80 /* Add the new device as a children of the bus. */
85 parent->children = dev;
88 /* If we don't have any other information about a device enable it */
95 * @brief round a number up to an alignment.
96 * @param val the starting value
97 * @param roundup Alignment as a power of two
98 * @returns rounded up number
100 static unsigned long round(unsigned long val, unsigned long roundup)
102 /* ROUNDUP MUST BE A POWER OF TWO. */
103 unsigned long inverse;
104 inverse = ~(roundup - 1);
105 val += (roundup - 1);
110 static unsigned long round_down(unsigned long val, unsigned long round_down)
112 /* ROUND_DOWN MUST BE A POWER OF TWO. */
113 unsigned long inverse;
114 inverse = ~(round_down - 1);
120 /** Read the resources on all devices of a given bus.
121 * @param bus bus to read the resources on.
123 static void read_resources(struct bus *bus)
125 struct device *curdev;
127 /* Walk through all of the devices and find which resources they need. */
128 for (curdev = bus->children; curdev; curdev = curdev->sibling) {
131 if (curdev->resources > 0) {
134 if (!curdev->ops || !curdev->ops->read_resources) {
135 printk_err("%s missing read_resources\n",
139 if (!curdev->enabled) {
143 curdev->ops->read_resources(curdev);
145 /* Read in subtractive resources behind the current device */
147 for (i = 0; i < curdev->resources; i++) {
148 struct resource *resource;
149 resource = &curdev->resource[i];
150 if ((resource->flags & IORESOURCE_SUBTRACTIVE) &&
151 (!(links & (1 << resource->index))))
153 links |= (1 << resource->index);
154 read_resources(&curdev->link[resource->index]);
161 struct pick_largest_state {
162 struct resource *last;
163 struct device *result_dev;
164 struct resource *result;
168 static void pick_largest_resource(struct pick_largest_state *state,
169 struct device *dev, struct resource *resource)
171 struct resource *last;
173 /* Be certain to pick the successor to last */
174 if (resource == last) {
175 state->seen_last = 1;
179 ((last->align < resource->align) ||
180 ((last->align == resource->align) &&
181 (last->size < resource->size)) ||
182 ((last->align == resource->align) &&
183 (last->size == resource->size) &&
184 (!state->seen_last)))) {
187 if (!state->result ||
188 (state->result->align < resource->align) ||
189 ((state->result->align == resource->align) &&
190 (state->result->size < resource->size))) {
191 state->result_dev = dev;
192 state->result = resource;
196 static void find_largest_resource(struct pick_largest_state *state,
197 struct bus *bus, unsigned long type_mask,
200 struct device *curdev;
202 for (curdev = bus->children; curdev; curdev = curdev->sibling) {
204 for (i = 0; i < curdev->resources; i++) {
205 struct resource *resource = &curdev->resource[i];
206 /* If it isn't the right kind of resource ignore it */
207 if ((resource->flags & type_mask) != type) {
210 /* If it is a subtractive resource recurse */
211 if (resource->flags & IORESOURCE_SUBTRACTIVE) {
213 subbus = &curdev->link[resource->index];
214 find_largest_resource(state, subbus,
218 /* See if this is the largest resource */
219 pick_largest_resource(state, curdev, resource);
224 static struct device *largest_resource(struct bus *bus,
225 struct resource **result_res,
226 unsigned long type_mask,
229 struct pick_largest_state state;
231 state.last = *result_res;
232 state.result_dev = 0;
236 find_largest_resource(&state, bus, type_mask, type);
238 *result_res = state.result;
239 return state.result_dev;
242 /* Compute allocate resources is the guts of the resource allocator.
245 * - Allocate resources locations for every device.
246 * - Don't overlap, and follow the rules of bridges.
247 * - Don't overlap with resources in fixed locations.
248 * - Be efficient so we don't have ugly strategies.
251 * - Devices that have fixed addresses are the minority so don't
252 * worry about them too much. Instead only use part of the address
253 * space for devices with programmable addresses. This easily handles
254 * everything except bridges.
256 * - PCI devices are required to have thier sizes and their alignments
257 * equal. In this case an optimal solution to the packing problem
258 * exists. Allocate all devices from highest alignment to least
259 * alignment or vice versa. Use this.
261 * - So we can handle more than PCI run two allocation passes on
262 * bridges. The first to see how large the resources are behind
263 * the bridge, and what their alignment requirements are. The
264 * second to assign a safe address to the devices behind the
265 * bridge. This allows me to treat a bridge as just a device with
266 * a couple of resources, and not need to special case it in the
267 * allocator. Also this allows handling of other types of bridges.
271 void compute_allocate_resource(
273 struct resource *bridge,
274 unsigned long type_mask,
278 struct resource *resource;
280 unsigned long align, min_align;
284 printk_spew("%s compute_allocate_%s: base: %08lx size: %08lx "
285 "align: %d gran: %d\n",
287 (bridge->flags & IORESOURCE_IO)? "io":
288 (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
289 base, bridge->size, bridge->align, bridge->gran);
291 /* We want different minimum alignments for different kinds of
292 * resources. These minimums are not device type specific
293 * but resource type specific.
295 if (bridge->flags & IORESOURCE_IO) {
296 min_align = log2(DEVICE_IO_ALIGN);
298 if (bridge->flags & IORESOURCE_MEM) {
299 min_align = log2(DEVICE_MEM_ALIGN);
302 /* Make certain I have read in all of the resources */
305 /* Remember I haven't found anything yet. */
308 /* Walk through all the devices on the current bus and compute the
310 while ((dev = largest_resource(bus, &resource, type_mask, type))) {
312 /* Do NOT I repeat do not ignore resources which have zero size.
313 * If they need to be ignored dev->read_resources should not even
314 * return them. Some resources must be set even when they have
315 * no size. PCI bridge resources are a good example of this.
318 /* Propogate the resource alignment to the bridge register */
319 if (resource->align > bridge->align) {
320 bridge->align = resource->align;
323 /* Make certain we are dealing with a good minimum size */
324 size = resource->size;
325 align = resource->align;
326 if (align < min_align) {
329 if (resource->flags & IORESOURCE_FIXED) {
332 if (resource->flags & IORESOURCE_IO) {
333 /* Don't allow potential aliases over the
334 * legacy pci expansion card addresses.
335 * The legacy pci decodes only 10 bits,
336 * uses 100h - 3ffh. Therefor, only 0 - ff
337 * can be used out of each 400h block of io
340 if ((base & 0x300) != 0) {
341 base = (base & ~0x3ff) + 0x400;
343 /* Don't allow allocations in the VGA IO range.
344 * PCI has special cases for that.
346 else if ((base >= 0x3b0) && (base <= 0x3df)) {
350 if (((round(base, 1UL << align) + size) -1) <= resource->limit) {
351 /* base must be aligned to size */
352 base = round(base, 1UL << align);
353 resource->base = base;
354 resource->flags |= IORESOURCE_ASSIGNED;
355 resource->flags &= ~IORESOURCE_STORED;
358 printk_spew("%s %02x * [0x%08lx - 0x%08lx] %s\n",
360 resource->index, resource->base,
361 resource->base + resource->size - 1,
362 (resource->flags & IORESOURCE_IO)? "io":
363 (resource->flags & IORESOURCE_PREFETCH)? "prefmem": "mem");
366 /* A pci bridge resource does not need to be a power
367 * of two size, but it does have a minimum granularity.
368 * Round the size up to that minimum granularity so we
369 * know not to place something else at an address postitively
370 * decoded by the bridge.
372 bridge->size = round(base, 1UL << bridge->gran) - bridge->base;
374 printk_spew("%s compute_allocate_%s: base: %08lx size: %08lx align: %d gran: %d done\n",
376 (bridge->flags & IORESOURCE_IO)? "io":
377 (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
378 base, bridge->size, bridge->align, bridge->gran);
383 static void allocate_vga_resource(void)
385 #warning "FIXME modify allocate_vga_resource so it is less pci centric!"
386 #warning "This function knows to much about PCI stuff, it should be just a ietrator/visitor."
388 /* FIXME handle the VGA pallette snooping */
389 struct device *dev, *vga = 0;
392 for (dev = all_devices; dev; dev = dev->next) {
393 if (((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) &&
394 ((dev->class >> 8) != PCI_CLASS_DISPLAY_OTHER)) {
396 printk_debug("Allocating VGA resource %s\n", dev_path(dev));
400 /* All legacy VGA cards have MEM & I/O space registers */
401 dev->command |= PCI_COMMAND_MEMORY | PCI_COMMAND_IO;
403 /* It isn't safe to enable other VGA cards */
404 dev->command &= ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
412 /* Now walk up the bridges setting the VGA enable */
414 bus->bridge_ctrl |= PCI_BRIDGE_CTL_VGA;
415 bus = (bus == bus->dev->bus)? 0 : bus->dev->bus;
420 /** Assign the computed resources to the bridges and devices on the bus.
421 * Recurse to any bridges found on this bus first. Then do the devices
424 * @param bus Pointer to the structure for this bus
426 void assign_resources(struct bus *bus)
428 struct device *curdev;
430 printk_debug("ASSIGN RESOURCES, bus %d\n", bus->secondary);
432 for (curdev = bus->children; curdev; curdev = curdev->sibling) {
433 if (!curdev->ops || !curdev->ops->set_resources) {
434 printk_err("%s missing set_resources\n",
438 if (!curdev->enabled) {
441 curdev->ops->set_resources(curdev);
443 printk_debug("ASSIGNED RESOURCES, bus %d\n", bus->secondary);
447 * @brief Enable the resources for a specific device
449 * @param dev the device whose resources are to be enabled
451 * Enable resources of the device by calling the device specific
452 * enable_resources() method.
454 * The parent's resources should be enabled first to avoid having enabling
455 * order problem. This is done by calling the parent's enable_resources()
456 * method and let that method to call it's children's enable_resoruces() via
457 * enable_childrens_resources().
459 * Indirect mutual recursion:
461 void enable_resources(struct device *dev)
463 if (!dev->ops || !dev->ops->enable_resources) {
464 printk_err("%s missing enable_resources\n", dev_path(dev));
470 dev->ops->enable_resources(dev);
474 * @brief Determine the existence of dynamic devices and construct dynamic
477 * Start form the root device 'dev_root', scan the buses in the system
478 * recursively, build the dynamic device tree according to the result
481 * This function has no idea how to scan and probe buses and devices at all.
482 * It depends on the bus/device specific scan_bus() method to do it. The
483 * scan_bus() function also have to create the device structure and attach
484 * it to the device tree.
486 void dev_enumerate(void)
489 unsigned subordinate;
491 printk_info("Enumerating buses...\n");
494 subordinate = root->ops->scan_bus(root, 0);
496 printk_info("done\n");
500 * @brief Configure devices on the devices tree.
502 * Starting at the root of the dynamic device tree, travel recursively,
503 * compute resources needed by each device and allocate them.
505 * I/O resources start at DEVICE_IO_START and grow upward. MEM resources start
506 * at DEVICE_MEM_START and grow downward.
508 * Since the assignment is hierarchical we set the values into the dev_root
511 void dev_configure(void)
513 struct device *root = &dev_root;
515 printk_info("Allocating resources...\n");
517 root->ops->read_resources(root);
519 /* Make certain the io devices are allocated somewhere safe. */
520 root->resource[0].base = DEVICE_IO_START;
521 root->resource[0].flags |= IORESOURCE_ASSIGNED;
522 root->resource[0].flags &= ~IORESOURCE_STORED;
524 /* Now reallocate the pci resources memory with the highest
525 * addresses I can manage.*/
526 root->resource[1].base =
527 round_down(DEVICE_MEM_HIGH - root->resource[1].size,
528 1UL << root->resource[1].align);
529 root->resource[1].flags |= IORESOURCE_ASSIGNED;
530 root->resource[1].flags &= ~IORESOURCE_STORED;
532 /* Allocate the VGA I/O resource.. */
533 allocate_vga_resource();
535 /* now just set things into registers ... we hope ... */
536 root->ops->set_resources(root);
538 printk_info("done.\n");
542 * @brief Enable devices on the device tree.
544 * Starting at the root, walk the tree and enable all devices/bridges by
545 * calling the device's enable_resources() method.
547 void dev_enable(void)
549 printk_info("Enabling resourcess...\n");
551 /* now enable everything. */
552 enable_resources(&dev_root);
554 printk_info("done.\n");
558 * @brief Initialize all devices in the global device list.
560 * Starting at the first device on the global device link list,
561 * walk the list and call a driver to do device specific setup.
563 void dev_initialize(void)
567 printk_info("Initializing devices...\n");
569 for (dev = all_devices; dev; dev = dev->next) {
570 if (dev->enabled && dev->ops && dev->ops->init) {
571 printk_debug("%s init\n", dev_path(dev));
576 printk_info("Devices initialized\n");