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>
25 /** Linked list of ALL devices */
26 struct device *all_devices = &dev_root;
27 /** Pointer to the last device */
28 static struct device **last_dev_p = &dev_root.next;
30 /** The upper limit of MEM resource of the devices.
31 * Reserve 20M for the system */
32 #define DEVICE_MEM_HIGH 0xFEC00000UL
33 /** The lower limit of IO resource of the devices.
34 * Reserve 4k for ISA/Legacy devices */
35 #define DEVICE_IO_START 0x1000
38 * @brief Allocate a new device structure.
40 * Allocte a new device structure and attached it to the device tree as a child
43 * @param parent parent bus the newly created device attached to.
44 * @param path path to the device to be created.
46 * @return pointer to the newly created device structure.
50 device_t alloc_dev(struct bus *parent, struct device_path *path)
55 /* Find the last child of our parent */
56 for (child = parent->children; child && child->sibling; ) {
57 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 children of the bus. */
84 parent->children = dev;
87 /* If we don't have any other information about a device enable it */
94 * @brief round a number up to an alignment.
95 * @param val the starting value
96 * @param roundup Alignment as a power of two
97 * @returns rounded up number
99 static unsigned long round(unsigned long val, unsigned long roundup)
101 /* ROUNDUP MUST BE A POWER OF TWO. */
102 unsigned long inverse;
103 inverse = ~(roundup - 1);
104 val += (roundup - 1);
109 static unsigned long round_down(unsigned long val, unsigned long round_down)
111 /* ROUND_DOWN MUST BE A POWER OF TWO. */
112 unsigned long inverse;
113 inverse = ~(round_down - 1);
119 /** Read the resources on all devices of a given bus.
120 * @param bus bus to read the resources on.
122 static void read_resources(struct bus *bus)
124 struct device *curdev;
126 /* Walk through all of the devices and find which resources they need. */
127 for (curdev = bus->children; curdev; curdev = curdev->sibling) {
130 if (curdev->resources > 0) {
133 if (!curdev->ops || !curdev->ops->read_resources) {
134 printk_err("%s missing read_resources\n",
138 if (!curdev->enable) {
142 curdev->ops->read_resources(curdev);
144 /* Read in subtractive resources behind the current device */
146 for (i = 0; i < curdev->resources; i++) {
147 struct resource *resource;
148 resource = &curdev->resource[i];
149 if ((resource->flags & IORESOURCE_SUBTRACTIVE) &&
150 (!(links & (1 << resource->index))))
152 links |= (1 << resource->index);
153 read_resources(&curdev->link[resource->index]);
160 struct pick_largest_state {
161 struct resource *last;
162 struct device *result_dev;
163 struct resource *result;
167 static void pick_largest_resource(struct pick_largest_state *state,
168 struct device *dev, struct resource *resource)
170 struct resource *last;
172 /* Be certain to pick the successor to last */
173 if (resource == last) {
174 state->seen_last = 1;
178 ((last->align < resource->align) ||
179 ((last->align == resource->align) &&
180 (last->size < resource->size)) ||
181 ((last->align == resource->align) &&
182 (last->size == resource->size) &&
183 (!state->seen_last)))) {
186 if (!state->result ||
187 (state->result->align < resource->align) ||
188 ((state->result->align == resource->align) &&
189 (state->result->size < resource->size))) {
190 state->result_dev = dev;
191 state->result = resource;
195 static void find_largest_resource(struct pick_largest_state *state,
196 struct bus *bus, unsigned long type_mask,
199 struct device *curdev;
201 for (curdev = bus->children; curdev; curdev = curdev->sibling) {
203 for (i = 0; i < curdev->resources; i++) {
204 struct resource *resource = &curdev->resource[i];
205 /* If it isn't the right kind of resource ignore it */
206 if ((resource->flags & type_mask) != type) {
209 /* If it is a subtractive resource recurse */
210 if (resource->flags & IORESOURCE_SUBTRACTIVE) {
212 subbus = &curdev->link[resource->index];
213 find_largest_resource(state, subbus,
217 /* See if this is the largest resource */
218 pick_largest_resource(state, curdev, resource);
223 static struct device *largest_resource(struct bus *bus,
224 struct resource **result_res,
225 unsigned long type_mask,
228 struct pick_largest_state state;
230 state.last = *result_res;
231 state.result_dev = 0;
235 find_largest_resource(&state, bus, type_mask, type);
237 *result_res = state.result;
238 return state.result_dev;
241 /* Compute allocate resources is the guts of the resource allocator.
244 * - Allocate resources locations for every device.
245 * - Don't overlap, and follow the rules of bridges.
246 * - Don't overlap with resources in fixed locations.
247 * - Be efficient so we don't have ugly strategies.
250 * - Devices that have fixed addresses are the minority so don't
251 * worry about them too much. Instead only use part of the address
252 * space for devices with programmable addresses. This easily handles
253 * everything except bridges.
255 * - PCI devices are required to have thier sizes and their alignments
256 * equal. In this case an optimal solution to the packing problem
257 * exists. Allocate all devices from highest alignment to least
258 * alignment or vice versa. Use this.
260 * - So we can handle more than PCI run two allocation passes on
261 * bridges. The first to see how large the resources are behind
262 * the bridge, and what their alignment requirements are. The
263 * second to assign a safe address to the devices behind the
264 * bridge. This allows me to treat a bridge as just a device with
265 * a couple of resources, and not need to special case it in the
266 * allocator. Also this allows handling of other types of bridges.
270 void compute_allocate_resource(
272 struct resource *bridge,
273 unsigned long type_mask,
277 struct resource *resource;
279 unsigned long align, min_align;
283 printk_spew("%s compute_allocate_%s: base: %08lx size: %08lx "
284 "align: %d gran: %d\n",
286 (bridge->flags & IORESOURCE_IO)? "io":
287 (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
288 base, bridge->size, bridge->align, bridge->gran);
290 /* We want different minimum alignments for different kinds of
291 * resources. These minimums are not device type specific
292 * but resource type specific.
294 if (bridge->flags & IORESOURCE_IO) {
295 min_align = log2(DEVICE_IO_ALIGN);
297 if (bridge->flags & IORESOURCE_MEM) {
298 min_align = log2(DEVICE_MEM_ALIGN);
301 /* Make certain I have read in all of the resources */
304 /* Remember I haven't found anything yet. */
307 /* Walk through all the devices on the current bus and compute the
309 while ((dev = largest_resource(bus, &resource, type_mask, type))) {
311 /* Do NOT I repeat do not ignore resources which have zero size.
312 * If they need to be ignored dev->read_resources should not even
313 * return them. Some resources must be set even when they have
314 * no size. PCI bridge resources are a good example of this.
317 /* Propogate the resource alignment to the bridge register */
318 if (resource->align > bridge->align) {
319 bridge->align = resource->align;
322 /* Make certain we are dealing with a good minimum size */
323 size = resource->size;
324 align = resource->align;
325 if (align < min_align) {
328 if (resource->flags & IORESOURCE_FIXED) {
331 if (resource->flags & IORESOURCE_IO) {
332 /* Don't allow potential aliases over the
333 * legacy pci expansion card addresses.
334 * The legacy pci decodes only 10 bits,
335 * uses 100h - 3ffh. Therefor, only 0 - ff
336 * can be used out of each 400h block of io
339 if ((base & 0x300) != 0) {
340 base = (base & ~0x3ff) + 0x400;
342 /* Don't allow allocations in the VGA IO range.
343 * PCI has special cases for that.
345 else if ((base >= 0x3b0) && (base <= 0x3df)) {
349 if (((round(base, 1UL << align) + size) -1) <= resource->limit) {
350 /* base must be aligned to size */
351 base = round(base, 1UL << align);
352 resource->base = base;
353 resource->flags |= IORESOURCE_ASSIGNED;
354 resource->flags &= ~IORESOURCE_STORED;
358 "%s %02x * [0x%08lx - 0x%08lx] %s\n",
361 resource->base, resource->base + resource->size -1,
362 (resource->flags & IORESOURCE_IO)? "io":
363 (resource->flags & IORESOURCE_PREFETCH)? "prefmem": "mem");
367 /* A pci bridge resource does not need to be a power
368 * of two size, but it does have a minimum granularity.
369 * Round the size up to that minimum granularity so we
370 * know not to place something else at an address postitively
371 * decoded by the bridge.
373 bridge->size = round(base, 1UL << bridge->gran) - bridge->base;
375 printk_spew("%s compute_allocate_%s: base: %08lx size: %08lx align: %d gran: %d done\n",
377 (bridge->flags & IORESOURCE_IO)? "io":
378 (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
379 base, bridge->size, bridge->align, bridge->gran);
384 static void allocate_vga_resource(void)
386 #warning "FIXME modify allocate_vga_resource so it is less pci centric!"
387 #warning "This function knows to much about PCI stuff, it should be just a ietrator/visitor."
389 /* FIXME handle the VGA pallette snooping */
390 struct device *dev, *vga;
394 for(dev = all_devices; dev; dev = dev->next) {
395 if (((dev->class >> 16) == 0x03) &&
396 ((dev->class >> 8) != 0x380)) {
398 printk_debug("Allocating VGA resource\n");
402 /* All legacy VGA cards have MEM & I/O space registers */
403 dev->command |= PCI_COMMAND_MEMORY | PCI_COMMAND_IO;
405 /* It isn't safe to enable other VGA cards */
406 dev->command &= ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
413 /* Now walk up the bridges setting the VGA enable */
415 bus->bridge_ctrl |= PCI_BRIDGE_CTL_VGA;
416 bus = (bus == bus->dev->bus)? 0 : bus->dev->bus;
421 /** Assign the computed resources to the bridges and devices on the bus.
422 * 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->enable) {
441 curdev->ops->set_resources(curdev);
443 printk_debug("ASSIGNED RESOURCES, bus %d\n", bus->secondary);
446 void enable_resources(struct device *dev)
448 /* Enable the resources for a specific device.
449 * The parents resources should be enabled first to avoid
450 * having enabling ordering problems.
452 if (!dev->ops || !dev->ops->enable_resources) {
453 printk_err("%s missing enable_resources\n",
460 dev->ops->enable_resources(dev);
464 * @brief Determine the existence of dynamic devices and construct dynamic
467 * Start for the root device 'dev_root', scan the buses in the system, build
468 * the dynamic device tree according to the result of the probe.
470 * This function have no idea how to scan and probe the buses and devices at
471 * all. It depends on the bus/device specific scan_bus() method to do it.
472 * The scan_bus() function also have to create the device structure and attach
473 * it to the device tree.
475 void dev_enumerate(void)
478 unsigned subordinate;
480 printk_info("Enumerating buses...\n");
483 subordinate = root->ops->scan_bus(root, 0);
485 printk_info("done\n");
489 * @brief Configure devices on the devices tree.
491 * Starting at the root, compute what resources are needed and allocate them.
492 * I/O starts at PCI_IO_START. Since the assignment is hierarchical we
493 * set the values into the dev_root struct.
495 void dev_configure(void)
497 struct device *root = &dev_root;
499 printk_info("Allocating resources...");
502 root->ops->read_resources(root);
504 /* Make certain the io devices are allocated somewhere safe. */
505 root->resource[0].base = DEVICE_IO_START;
506 root->resource[0].flags |= IORESOURCE_ASSIGNED;
507 root->resource[0].flags &= ~IORESOURCE_STORED;
509 /* Now reallocate the pci resources memory with the highest
510 * addresses I can manage.*/
511 root->resource[1].base =
512 round_down(DEVICE_MEM_HIGH - root->resource[1].size,
513 1UL << root->resource[1].align);
514 root->resource[1].flags |= IORESOURCE_ASSIGNED;
515 root->resource[1].flags &= ~IORESOURCE_STORED;
517 /* Allocate the VGA I/O resource.. */
518 allocate_vga_resource();
520 /* now just set things into registers ... we hope ... */
521 root->ops->set_resources(root);
523 printk_info("done.\n");
527 * @brief Enable devices on the device tree.
529 * Starting at the root, walk the tree and enable all devices/bridges by
530 * calling the device's enable_resources() method.
532 void dev_enable(void)
534 printk_info("Enabling resourcess...\n");
536 /* now enable everything. */
537 enable_resources(&dev_root);
539 printk_info("done.\n");
543 * @brief Initialize all devices in the global device list.
545 * Starting at the first device on the global device link list,
546 * walk the list and call a driver to do device specific setup.
548 void dev_initialize(void)
552 printk_info("Initializing devices...\n");
554 for (dev = all_devices; dev; dev = dev->next) {
555 if (dev->enable && dev->ops && dev->ops->init) {
556 printk_debug("%s init\n", dev_path(dev));
561 printk_info("Devices initialized\n");