xref: /openbmc/linux/drivers/rapidio/rio-scan.c (revision fd589a8f)
1 /*
2  * RapidIO enumeration and discovery support
3  *
4  * Copyright 2005 MontaVista Software, Inc.
5  * Matt Porter <mporter@kernel.crashing.org>
6  *
7  * This program is free software; you can redistribute  it and/or modify it
8  * under  the terms of  the GNU General  Public License as published by the
9  * Free Software Foundation;  either version 2 of the  License, or (at your
10  * option) any later version.
11  */
12 
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 
16 #include <linux/delay.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/init.h>
19 #include <linux/rio.h>
20 #include <linux/rio_drv.h>
21 #include <linux/rio_ids.h>
22 #include <linux/rio_regs.h>
23 #include <linux/module.h>
24 #include <linux/spinlock.h>
25 #include <linux/timer.h>
26 #include <linux/jiffies.h>
27 #include <linux/slab.h>
28 
29 #include "rio.h"
30 
31 LIST_HEAD(rio_devices);
32 static LIST_HEAD(rio_switches);
33 
34 #define RIO_ENUM_CMPL_MAGIC	0xdeadbeef
35 
36 static void rio_enum_timeout(unsigned long);
37 
38 DEFINE_SPINLOCK(rio_global_list_lock);
39 
40 static int next_destid = 0;
41 static int next_switchid = 0;
42 static int next_net = 0;
43 
44 static struct timer_list rio_enum_timer =
45 TIMER_INITIALIZER(rio_enum_timeout, 0, 0);
46 
47 static int rio_mport_phys_table[] = {
48 	RIO_EFB_PAR_EP_ID,
49 	RIO_EFB_PAR_EP_REC_ID,
50 	RIO_EFB_SER_EP_ID,
51 	RIO_EFB_SER_EP_REC_ID,
52 	-1,
53 };
54 
55 static int rio_sport_phys_table[] = {
56 	RIO_EFB_PAR_EP_FREE_ID,
57 	RIO_EFB_SER_EP_FREE_ID,
58 	-1,
59 };
60 
61 /**
62  * rio_get_device_id - Get the base/extended device id for a device
63  * @port: RIO master port
64  * @destid: Destination ID of device
65  * @hopcount: Hopcount to device
66  *
67  * Reads the base/extended device id from a device. Returns the
68  * 8/16-bit device ID.
69  */
70 static u16 rio_get_device_id(struct rio_mport *port, u16 destid, u8 hopcount)
71 {
72 	u32 result;
73 
74 	rio_mport_read_config_32(port, destid, hopcount, RIO_DID_CSR, &result);
75 
76 	return RIO_GET_DID(port->sys_size, result);
77 }
78 
79 /**
80  * rio_set_device_id - Set the base/extended device id for a device
81  * @port: RIO master port
82  * @destid: Destination ID of device
83  * @hopcount: Hopcount to device
84  * @did: Device ID value to be written
85  *
86  * Writes the base/extended device id from a device.
87  */
88 static void rio_set_device_id(struct rio_mport *port, u16 destid, u8 hopcount, u16 did)
89 {
90 	rio_mport_write_config_32(port, destid, hopcount, RIO_DID_CSR,
91 				  RIO_SET_DID(port->sys_size, did));
92 }
93 
94 /**
95  * rio_local_set_device_id - Set the base/extended device id for a port
96  * @port: RIO master port
97  * @did: Device ID value to be written
98  *
99  * Writes the base/extended device id from a device.
100  */
101 static void rio_local_set_device_id(struct rio_mport *port, u16 did)
102 {
103 	rio_local_write_config_32(port, RIO_DID_CSR, RIO_SET_DID(port->sys_size,
104 				did));
105 }
106 
107 /**
108  * rio_clear_locks- Release all host locks and signal enumeration complete
109  * @port: Master port to issue transaction
110  *
111  * Marks the component tag CSR on each device with the enumeration
112  * complete flag. When complete, it then release the host locks on
113  * each device. Returns 0 on success or %-EINVAL on failure.
114  */
115 static int rio_clear_locks(struct rio_mport *port)
116 {
117 	struct rio_dev *rdev;
118 	u32 result;
119 	int ret = 0;
120 
121 	/* Write component tag CSR magic complete value */
122 	rio_local_write_config_32(port, RIO_COMPONENT_TAG_CSR,
123 				  RIO_ENUM_CMPL_MAGIC);
124 	list_for_each_entry(rdev, &rio_devices, global_list)
125 	    rio_write_config_32(rdev, RIO_COMPONENT_TAG_CSR,
126 				RIO_ENUM_CMPL_MAGIC);
127 
128 	/* Release host device id locks */
129 	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
130 				  port->host_deviceid);
131 	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
132 	if ((result & 0xffff) != 0xffff) {
133 		printk(KERN_INFO
134 		       "RIO: badness when releasing host lock on master port, result %8.8x\n",
135 		       result);
136 		ret = -EINVAL;
137 	}
138 	list_for_each_entry(rdev, &rio_devices, global_list) {
139 		rio_write_config_32(rdev, RIO_HOST_DID_LOCK_CSR,
140 				    port->host_deviceid);
141 		rio_read_config_32(rdev, RIO_HOST_DID_LOCK_CSR, &result);
142 		if ((result & 0xffff) != 0xffff) {
143 			printk(KERN_INFO
144 			       "RIO: badness when releasing host lock on vid %4.4x did %4.4x\n",
145 			       rdev->vid, rdev->did);
146 			ret = -EINVAL;
147 		}
148 	}
149 
150 	return ret;
151 }
152 
153 /**
154  * rio_enum_host- Set host lock and initialize host destination ID
155  * @port: Master port to issue transaction
156  *
157  * Sets the local host master port lock and destination ID register
158  * with the host device ID value. The host device ID value is provided
159  * by the platform. Returns %0 on success or %-1 on failure.
160  */
161 static int rio_enum_host(struct rio_mport *port)
162 {
163 	u32 result;
164 
165 	/* Set master port host device id lock */
166 	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
167 				  port->host_deviceid);
168 
169 	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
170 	if ((result & 0xffff) != port->host_deviceid)
171 		return -1;
172 
173 	/* Set master port destid and init destid ctr */
174 	rio_local_set_device_id(port, port->host_deviceid);
175 
176 	if (next_destid == port->host_deviceid)
177 		next_destid++;
178 
179 	return 0;
180 }
181 
182 /**
183  * rio_device_has_destid- Test if a device contains a destination ID register
184  * @port: Master port to issue transaction
185  * @src_ops: RIO device source operations
186  * @dst_ops: RIO device destination operations
187  *
188  * Checks the provided @src_ops and @dst_ops for the necessary transaction
189  * capabilities that indicate whether or not a device will implement a
190  * destination ID register. Returns 1 if true or 0 if false.
191  */
192 static int rio_device_has_destid(struct rio_mport *port, int src_ops,
193 				 int dst_ops)
194 {
195 	u32 mask = RIO_OPS_READ | RIO_OPS_WRITE | RIO_OPS_ATOMIC_TST_SWP | RIO_OPS_ATOMIC_INC | RIO_OPS_ATOMIC_DEC | RIO_OPS_ATOMIC_SET | RIO_OPS_ATOMIC_CLR;
196 
197 	return !!((src_ops | dst_ops) & mask);
198 }
199 
200 /**
201  * rio_release_dev- Frees a RIO device struct
202  * @dev: LDM device associated with a RIO device struct
203  *
204  * Gets the RIO device struct associated a RIO device struct.
205  * The RIO device struct is freed.
206  */
207 static void rio_release_dev(struct device *dev)
208 {
209 	struct rio_dev *rdev;
210 
211 	rdev = to_rio_dev(dev);
212 	kfree(rdev);
213 }
214 
215 /**
216  * rio_is_switch- Tests if a RIO device has switch capabilities
217  * @rdev: RIO device
218  *
219  * Gets the RIO device Processing Element Features register
220  * contents and tests for switch capabilities. Returns 1 if
221  * the device is a switch or 0 if it is not a switch.
222  * The RIO device struct is freed.
223  */
224 static int rio_is_switch(struct rio_dev *rdev)
225 {
226 	if (rdev->pef & RIO_PEF_SWITCH)
227 		return 1;
228 	return 0;
229 }
230 
231 /**
232  * rio_route_set_ops- Sets routing operations for a particular vendor switch
233  * @rdev: RIO device
234  *
235  * Searches the RIO route ops table for known switch types. If the vid
236  * and did match a switch table entry, then set the add_entry() and
237  * get_entry() ops to the table entry values.
238  */
239 static void rio_route_set_ops(struct rio_dev *rdev)
240 {
241 	struct rio_route_ops *cur = __start_rio_route_ops;
242 	struct rio_route_ops *end = __end_rio_route_ops;
243 
244 	while (cur < end) {
245 		if ((cur->vid == rdev->vid) && (cur->did == rdev->did)) {
246 			pr_debug("RIO: adding routing ops for %s\n", rio_name(rdev));
247 			rdev->rswitch->add_entry = cur->add_hook;
248 			rdev->rswitch->get_entry = cur->get_hook;
249 		}
250 		cur++;
251 	}
252 
253 	if (!rdev->rswitch->add_entry || !rdev->rswitch->get_entry)
254 		printk(KERN_ERR "RIO: missing routing ops for %s\n",
255 		       rio_name(rdev));
256 }
257 
258 /**
259  * rio_add_device- Adds a RIO device to the device model
260  * @rdev: RIO device
261  *
262  * Adds the RIO device to the global device list and adds the RIO
263  * device to the RIO device list.  Creates the generic sysfs nodes
264  * for an RIO device.
265  */
266 static int __devinit rio_add_device(struct rio_dev *rdev)
267 {
268 	int err;
269 
270 	err = device_add(&rdev->dev);
271 	if (err)
272 		return err;
273 
274 	spin_lock(&rio_global_list_lock);
275 	list_add_tail(&rdev->global_list, &rio_devices);
276 	spin_unlock(&rio_global_list_lock);
277 
278 	rio_create_sysfs_dev_files(rdev);
279 
280 	return 0;
281 }
282 
283 /**
284  * rio_setup_device- Allocates and sets up a RIO device
285  * @net: RIO network
286  * @port: Master port to send transactions
287  * @destid: Current destination ID
288  * @hopcount: Current hopcount
289  * @do_enum: Enumeration/Discovery mode flag
290  *
291  * Allocates a RIO device and configures fields based on configuration
292  * space contents. If device has a destination ID register, a destination
293  * ID is either assigned in enumeration mode or read from configuration
294  * space in discovery mode.  If the device has switch capabilities, then
295  * a switch is allocated and configured appropriately. Returns a pointer
296  * to a RIO device on success or NULL on failure.
297  *
298  */
299 static struct rio_dev __devinit *rio_setup_device(struct rio_net *net,
300 					struct rio_mport *port, u16 destid,
301 					u8 hopcount, int do_enum)
302 {
303 	int ret = 0;
304 	struct rio_dev *rdev;
305 	struct rio_switch *rswitch = NULL;
306 	int result, rdid;
307 
308 	rdev = kzalloc(sizeof(struct rio_dev), GFP_KERNEL);
309 	if (!rdev)
310 		return NULL;
311 
312 	rdev->net = net;
313 	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_ID_CAR,
314 				 &result);
315 	rdev->did = result >> 16;
316 	rdev->vid = result & 0xffff;
317 	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_INFO_CAR,
318 				 &rdev->device_rev);
319 	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_ID_CAR,
320 				 &result);
321 	rdev->asm_did = result >> 16;
322 	rdev->asm_vid = result & 0xffff;
323 	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_INFO_CAR,
324 				 &result);
325 	rdev->asm_rev = result >> 16;
326 	rio_mport_read_config_32(port, destid, hopcount, RIO_PEF_CAR,
327 				 &rdev->pef);
328 	if (rdev->pef & RIO_PEF_EXT_FEATURES)
329 		rdev->efptr = result & 0xffff;
330 
331 	rio_mport_read_config_32(port, destid, hopcount, RIO_SRC_OPS_CAR,
332 				 &rdev->src_ops);
333 	rio_mport_read_config_32(port, destid, hopcount, RIO_DST_OPS_CAR,
334 				 &rdev->dst_ops);
335 
336 	if (rio_device_has_destid(port, rdev->src_ops, rdev->dst_ops)) {
337 		if (do_enum) {
338 			rio_set_device_id(port, destid, hopcount, next_destid);
339 			rdev->destid = next_destid++;
340 			if (next_destid == port->host_deviceid)
341 				next_destid++;
342 		} else
343 			rdev->destid = rio_get_device_id(port, destid, hopcount);
344 	} else
345 		/* Switch device has an associated destID */
346 		rdev->destid = RIO_INVALID_DESTID;
347 
348 	/* If a PE has both switch and other functions, show it as a switch */
349 	if (rio_is_switch(rdev)) {
350 		rio_mport_read_config_32(port, destid, hopcount,
351 					 RIO_SWP_INFO_CAR, &rdev->swpinfo);
352 		rswitch = kmalloc(sizeof(struct rio_switch), GFP_KERNEL);
353 		if (!rswitch)
354 			goto cleanup;
355 		rswitch->switchid = next_switchid;
356 		rswitch->hopcount = hopcount;
357 		rswitch->destid = destid;
358 		rswitch->route_table = kzalloc(sizeof(u8)*
359 					RIO_MAX_ROUTE_ENTRIES(port->sys_size),
360 					GFP_KERNEL);
361 		if (!rswitch->route_table)
362 			goto cleanup;
363 		/* Initialize switch route table */
364 		for (rdid = 0; rdid < RIO_MAX_ROUTE_ENTRIES(port->sys_size);
365 				rdid++)
366 			rswitch->route_table[rdid] = RIO_INVALID_ROUTE;
367 		rdev->rswitch = rswitch;
368 		dev_set_name(&rdev->dev, "%02x:s:%04x", rdev->net->id,
369 			     rdev->rswitch->switchid);
370 		rio_route_set_ops(rdev);
371 
372 		list_add_tail(&rswitch->node, &rio_switches);
373 
374 	} else
375 		dev_set_name(&rdev->dev, "%02x:e:%04x", rdev->net->id,
376 			     rdev->destid);
377 
378 	rdev->dev.bus = &rio_bus_type;
379 
380 	device_initialize(&rdev->dev);
381 	rdev->dev.release = rio_release_dev;
382 	rio_dev_get(rdev);
383 
384 	rdev->dma_mask = DMA_BIT_MASK(32);
385 	rdev->dev.dma_mask = &rdev->dma_mask;
386 	rdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
387 
388 	if ((rdev->pef & RIO_PEF_INB_DOORBELL) &&
389 	    (rdev->dst_ops & RIO_DST_OPS_DOORBELL))
390 		rio_init_dbell_res(&rdev->riores[RIO_DOORBELL_RESOURCE],
391 				   0, 0xffff);
392 
393 	ret = rio_add_device(rdev);
394 	if (ret)
395 		goto cleanup;
396 
397 	return rdev;
398 
399 cleanup:
400 	if (rswitch) {
401 		kfree(rswitch->route_table);
402 		kfree(rswitch);
403 	}
404 	kfree(rdev);
405 	return NULL;
406 }
407 
408 /**
409  * rio_sport_is_active- Tests if a switch port has an active connection.
410  * @port: Master port to send transaction
411  * @destid: Associated destination ID for switch
412  * @hopcount: Hopcount to reach switch
413  * @sport: Switch port number
414  *
415  * Reads the port error status CSR for a particular switch port to
416  * determine if the port has an active link.  Returns
417  * %PORT_N_ERR_STS_PORT_OK if the port is active or %0 if it is
418  * inactive.
419  */
420 static int
421 rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport)
422 {
423 	u32 result;
424 	u32 ext_ftr_ptr;
425 
426 	int *entry = rio_sport_phys_table;
427 
428 	do {
429 		if ((ext_ftr_ptr =
430 		     rio_mport_get_feature(port, 0, destid, hopcount, *entry)))
431 
432 			break;
433 	} while (*++entry >= 0);
434 
435 	if (ext_ftr_ptr)
436 		rio_mport_read_config_32(port, destid, hopcount,
437 					 ext_ftr_ptr +
438 					 RIO_PORT_N_ERR_STS_CSR(sport),
439 					 &result);
440 
441 	return (result & PORT_N_ERR_STS_PORT_OK);
442 }
443 
444 /**
445  * rio_route_add_entry- Add a route entry to a switch routing table
446  * @mport: Master port to send transaction
447  * @rswitch: Switch device
448  * @table: Routing table ID
449  * @route_destid: Destination ID to be routed
450  * @route_port: Port number to be routed
451  *
452  * Calls the switch specific add_entry() method to add a route entry
453  * on a switch. The route table can be specified using the @table
454  * argument if a switch has per port routing tables or the normal
455  * use is to specific all tables (or the global table) by passing
456  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
457  * on failure.
458  */
459 static int rio_route_add_entry(struct rio_mport *mport, struct rio_switch *rswitch,
460 			       u16 table, u16 route_destid, u8 route_port)
461 {
462 	return rswitch->add_entry(mport, rswitch->destid,
463 					rswitch->hopcount, table,
464 					route_destid, route_port);
465 }
466 
467 /**
468  * rio_route_get_entry- Read a route entry in a switch routing table
469  * @mport: Master port to send transaction
470  * @rswitch: Switch device
471  * @table: Routing table ID
472  * @route_destid: Destination ID to be routed
473  * @route_port: Pointer to read port number into
474  *
475  * Calls the switch specific get_entry() method to read a route entry
476  * in a switch. The route table can be specified using the @table
477  * argument if a switch has per port routing tables or the normal
478  * use is to specific all tables (or the global table) by passing
479  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
480  * on failure.
481  */
482 static int
483 rio_route_get_entry(struct rio_mport *mport, struct rio_switch *rswitch, u16 table,
484 		    u16 route_destid, u8 * route_port)
485 {
486 	return rswitch->get_entry(mport, rswitch->destid,
487 					rswitch->hopcount, table,
488 					route_destid, route_port);
489 }
490 
491 /**
492  * rio_get_host_deviceid_lock- Reads the Host Device ID Lock CSR on a device
493  * @port: Master port to send transaction
494  * @hopcount: Number of hops to the device
495  *
496  * Used during enumeration to read the Host Device ID Lock CSR on a
497  * RIO device. Returns the value of the lock register.
498  */
499 static u16 rio_get_host_deviceid_lock(struct rio_mport *port, u8 hopcount)
500 {
501 	u32 result;
502 
503 	rio_mport_read_config_32(port, RIO_ANY_DESTID(port->sys_size), hopcount,
504 				 RIO_HOST_DID_LOCK_CSR, &result);
505 
506 	return (u16) (result & 0xffff);
507 }
508 
509 /**
510  * rio_get_swpinfo_inport- Gets the ingress port number
511  * @mport: Master port to send transaction
512  * @destid: Destination ID associated with the switch
513  * @hopcount: Number of hops to the device
514  *
515  * Returns port number being used to access the switch device.
516  */
517 static u8
518 rio_get_swpinfo_inport(struct rio_mport *mport, u16 destid, u8 hopcount)
519 {
520 	u32 result;
521 
522 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
523 				 &result);
524 
525 	return (u8) (result & 0xff);
526 }
527 
528 /**
529  * rio_get_swpinfo_tports- Gets total number of ports on the switch
530  * @mport: Master port to send transaction
531  * @destid: Destination ID associated with the switch
532  * @hopcount: Number of hops to the device
533  *
534  * Returns total numbers of ports implemented by the switch device.
535  */
536 static u8 rio_get_swpinfo_tports(struct rio_mport *mport, u16 destid,
537 				 u8 hopcount)
538 {
539 	u32 result;
540 
541 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
542 				 &result);
543 
544 	return RIO_GET_TOTAL_PORTS(result);
545 }
546 
547 /**
548  * rio_net_add_mport- Add a master port to a RIO network
549  * @net: RIO network
550  * @port: Master port to add
551  *
552  * Adds a master port to the network list of associated master
553  * ports..
554  */
555 static void rio_net_add_mport(struct rio_net *net, struct rio_mport *port)
556 {
557 	spin_lock(&rio_global_list_lock);
558 	list_add_tail(&port->nnode, &net->mports);
559 	spin_unlock(&rio_global_list_lock);
560 }
561 
562 /**
563  * rio_enum_peer- Recursively enumerate a RIO network through a master port
564  * @net: RIO network being enumerated
565  * @port: Master port to send transactions
566  * @hopcount: Number of hops into the network
567  *
568  * Recursively enumerates a RIO network.  Transactions are sent via the
569  * master port passed in @port.
570  */
571 static int __devinit rio_enum_peer(struct rio_net *net, struct rio_mport *port,
572 			 u8 hopcount)
573 {
574 	int port_num;
575 	int num_ports;
576 	int cur_destid;
577 	int sw_destid;
578 	int sw_inport;
579 	struct rio_dev *rdev;
580 	u16 destid;
581 	int tmp;
582 
583 	if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
584 		pr_debug("RIO: PE already discovered by this host\n");
585 		/*
586 		 * Already discovered by this host. Add it as another
587 		 * master port for the current network.
588 		 */
589 		rio_net_add_mport(net, port);
590 		return 0;
591 	}
592 
593 	/* Attempt to acquire device lock */
594 	rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
595 				  hopcount,
596 				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
597 	while ((tmp = rio_get_host_deviceid_lock(port, hopcount))
598 	       < port->host_deviceid) {
599 		/* Delay a bit */
600 		mdelay(1);
601 		/* Attempt to acquire device lock again */
602 		rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
603 					  hopcount,
604 					  RIO_HOST_DID_LOCK_CSR,
605 					  port->host_deviceid);
606 	}
607 
608 	if (rio_get_host_deviceid_lock(port, hopcount) > port->host_deviceid) {
609 		pr_debug(
610 		    "RIO: PE locked by a higher priority host...retreating\n");
611 		return -1;
612 	}
613 
614 	/* Setup new RIO device */
615 	rdev = rio_setup_device(net, port, RIO_ANY_DESTID(port->sys_size),
616 					hopcount, 1);
617 	if (rdev) {
618 		/* Add device to the global and bus/net specific list. */
619 		list_add_tail(&rdev->net_list, &net->devices);
620 	} else
621 		return -1;
622 
623 	if (rio_is_switch(rdev)) {
624 		next_switchid++;
625 		sw_inport = rio_get_swpinfo_inport(port,
626 				RIO_ANY_DESTID(port->sys_size), hopcount);
627 		rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,
628 				    port->host_deviceid, sw_inport);
629 		rdev->rswitch->route_table[port->host_deviceid] = sw_inport;
630 
631 		for (destid = 0; destid < next_destid; destid++) {
632 			if (destid == port->host_deviceid)
633 				continue;
634 			rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,
635 					    destid, sw_inport);
636 			rdev->rswitch->route_table[destid] = sw_inport;
637 		}
638 
639 		num_ports =
640 		    rio_get_swpinfo_tports(port, RIO_ANY_DESTID(port->sys_size),
641 						hopcount);
642 		pr_debug(
643 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
644 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
645 		sw_destid = next_destid;
646 		for (port_num = 0; port_num < num_ports; port_num++) {
647 			if (sw_inport == port_num)
648 				continue;
649 
650 			cur_destid = next_destid;
651 
652 			if (rio_sport_is_active
653 			    (port, RIO_ANY_DESTID(port->sys_size), hopcount,
654 			     port_num)) {
655 				pr_debug(
656 				    "RIO: scanning device on port %d\n",
657 				    port_num);
658 				rio_route_add_entry(port, rdev->rswitch,
659 						RIO_GLOBAL_TABLE,
660 						RIO_ANY_DESTID(port->sys_size),
661 						port_num);
662 
663 				if (rio_enum_peer(net, port, hopcount + 1) < 0)
664 					return -1;
665 
666 				/* Update routing tables */
667 				if (next_destid > cur_destid) {
668 					for (destid = cur_destid;
669 					     destid < next_destid; destid++) {
670 						if (destid == port->host_deviceid)
671 							continue;
672 						rio_route_add_entry(port, rdev->rswitch,
673 								    RIO_GLOBAL_TABLE,
674 								    destid,
675 								    port_num);
676 						rdev->rswitch->
677 						    route_table[destid] =
678 						    port_num;
679 					}
680 				}
681 			}
682 		}
683 
684 		/* Check for empty switch */
685 		if (next_destid == sw_destid) {
686 			next_destid++;
687 			if (next_destid == port->host_deviceid)
688 				next_destid++;
689 		}
690 
691 		rdev->rswitch->destid = sw_destid;
692 	} else
693 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
694 		    rio_name(rdev), rdev->vid, rdev->did);
695 
696 	return 0;
697 }
698 
699 /**
700  * rio_enum_complete- Tests if enumeration of a network is complete
701  * @port: Master port to send transaction
702  *
703  * Tests the Component Tag CSR for presence of the magic enumeration
704  * complete flag. Return %1 if enumeration is complete or %0 if
705  * enumeration is incomplete.
706  */
707 static int rio_enum_complete(struct rio_mport *port)
708 {
709 	u32 tag_csr;
710 	int ret = 0;
711 
712 	rio_local_read_config_32(port, RIO_COMPONENT_TAG_CSR, &tag_csr);
713 
714 	if (tag_csr == RIO_ENUM_CMPL_MAGIC)
715 		ret = 1;
716 
717 	return ret;
718 }
719 
720 /**
721  * rio_disc_peer- Recursively discovers a RIO network through a master port
722  * @net: RIO network being discovered
723  * @port: Master port to send transactions
724  * @destid: Current destination ID in network
725  * @hopcount: Number of hops into the network
726  *
727  * Recursively discovers a RIO network.  Transactions are sent via the
728  * master port passed in @port.
729  */
730 static int __devinit
731 rio_disc_peer(struct rio_net *net, struct rio_mport *port, u16 destid,
732 	      u8 hopcount)
733 {
734 	u8 port_num, route_port;
735 	int num_ports;
736 	struct rio_dev *rdev;
737 	u16 ndestid;
738 
739 	/* Setup new RIO device */
740 	if ((rdev = rio_setup_device(net, port, destid, hopcount, 0))) {
741 		/* Add device to the global and bus/net specific list. */
742 		list_add_tail(&rdev->net_list, &net->devices);
743 	} else
744 		return -1;
745 
746 	if (rio_is_switch(rdev)) {
747 		next_switchid++;
748 
749 		/* Associated destid is how we accessed this switch */
750 		rdev->rswitch->destid = destid;
751 
752 		num_ports = rio_get_swpinfo_tports(port, destid, hopcount);
753 		pr_debug(
754 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
755 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
756 		for (port_num = 0; port_num < num_ports; port_num++) {
757 			if (rio_get_swpinfo_inport(port, destid, hopcount) ==
758 			    port_num)
759 				continue;
760 
761 			if (rio_sport_is_active
762 			    (port, destid, hopcount, port_num)) {
763 				pr_debug(
764 				    "RIO: scanning device on port %d\n",
765 				    port_num);
766 				for (ndestid = 0;
767 				     ndestid < RIO_ANY_DESTID(port->sys_size);
768 				     ndestid++) {
769 					rio_route_get_entry(port, rdev->rswitch,
770 							    RIO_GLOBAL_TABLE,
771 							    ndestid,
772 							    &route_port);
773 					if (route_port == port_num)
774 						break;
775 				}
776 
777 				if (rio_disc_peer
778 				    (net, port, ndestid, hopcount + 1) < 0)
779 					return -1;
780 			}
781 		}
782 	} else
783 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
784 		    rio_name(rdev), rdev->vid, rdev->did);
785 
786 	return 0;
787 }
788 
789 /**
790  * rio_mport_is_active- Tests if master port link is active
791  * @port: Master port to test
792  *
793  * Reads the port error status CSR for the master port to
794  * determine if the port has an active link.  Returns
795  * %PORT_N_ERR_STS_PORT_OK if the  master port is active
796  * or %0 if it is inactive.
797  */
798 static int rio_mport_is_active(struct rio_mport *port)
799 {
800 	u32 result = 0;
801 	u32 ext_ftr_ptr;
802 	int *entry = rio_mport_phys_table;
803 
804 	do {
805 		if ((ext_ftr_ptr =
806 		     rio_mport_get_feature(port, 1, 0, 0, *entry)))
807 			break;
808 	} while (*++entry >= 0);
809 
810 	if (ext_ftr_ptr)
811 		rio_local_read_config_32(port,
812 					 ext_ftr_ptr +
813 					 RIO_PORT_N_ERR_STS_CSR(port->index),
814 					 &result);
815 
816 	return (result & PORT_N_ERR_STS_PORT_OK);
817 }
818 
819 /**
820  * rio_alloc_net- Allocate and configure a new RIO network
821  * @port: Master port associated with the RIO network
822  *
823  * Allocates a RIO network structure, initializes per-network
824  * list heads, and adds the associated master port to the
825  * network list of associated master ports. Returns a
826  * RIO network pointer on success or %NULL on failure.
827  */
828 static struct rio_net __devinit *rio_alloc_net(struct rio_mport *port)
829 {
830 	struct rio_net *net;
831 
832 	net = kzalloc(sizeof(struct rio_net), GFP_KERNEL);
833 	if (net) {
834 		INIT_LIST_HEAD(&net->node);
835 		INIT_LIST_HEAD(&net->devices);
836 		INIT_LIST_HEAD(&net->mports);
837 		list_add_tail(&port->nnode, &net->mports);
838 		net->hport = port;
839 		net->id = next_net++;
840 	}
841 	return net;
842 }
843 
844 /**
845  * rio_update_route_tables- Updates route tables in switches
846  * @port: Master port associated with the RIO network
847  *
848  * For each enumerated device, ensure that each switch in a system
849  * has correct routing entries. Add routes for devices that where
850  * unknown dirung the first enumeration pass through the switch.
851  */
852 static void rio_update_route_tables(struct rio_mport *port)
853 {
854 	struct rio_dev *rdev;
855 	struct rio_switch *rswitch;
856 	u8 sport;
857 	u16 destid;
858 
859 	list_for_each_entry(rdev, &rio_devices, global_list) {
860 
861 		destid = (rio_is_switch(rdev))?rdev->rswitch->destid:rdev->destid;
862 
863 		list_for_each_entry(rswitch, &rio_switches, node) {
864 
865 			if (rio_is_switch(rdev)	&& (rdev->rswitch == rswitch))
866 				continue;
867 
868 			if (RIO_INVALID_ROUTE == rswitch->route_table[destid]) {
869 
870 				sport = rio_get_swpinfo_inport(port,
871 						rswitch->destid, rswitch->hopcount);
872 
873 				if (rswitch->add_entry)	{
874 					rio_route_add_entry(port, rswitch, RIO_GLOBAL_TABLE, destid, sport);
875 					rswitch->route_table[destid] = sport;
876 				}
877 			}
878 		}
879 	}
880 }
881 
882 /**
883  * rio_enum_mport- Start enumeration through a master port
884  * @mport: Master port to send transactions
885  *
886  * Starts the enumeration process. If somebody has enumerated our
887  * master port device, then give up. If not and we have an active
888  * link, then start recursive peer enumeration. Returns %0 if
889  * enumeration succeeds or %-EBUSY if enumeration fails.
890  */
891 int __devinit rio_enum_mport(struct rio_mport *mport)
892 {
893 	struct rio_net *net = NULL;
894 	int rc = 0;
895 
896 	printk(KERN_INFO "RIO: enumerate master port %d, %s\n", mport->id,
897 	       mport->name);
898 	/* If somebody else enumerated our master port device, bail. */
899 	if (rio_enum_host(mport) < 0) {
900 		printk(KERN_INFO
901 		       "RIO: master port %d device has been enumerated by a remote host\n",
902 		       mport->id);
903 		rc = -EBUSY;
904 		goto out;
905 	}
906 
907 	/* If master port has an active link, allocate net and enum peers */
908 	if (rio_mport_is_active(mport)) {
909 		if (!(net = rio_alloc_net(mport))) {
910 			printk(KERN_ERR "RIO: failed to allocate new net\n");
911 			rc = -ENOMEM;
912 			goto out;
913 		}
914 		if (rio_enum_peer(net, mport, 0) < 0) {
915 			/* A higher priority host won enumeration, bail. */
916 			printk(KERN_INFO
917 			       "RIO: master port %d device has lost enumeration to a remote host\n",
918 			       mport->id);
919 			rio_clear_locks(mport);
920 			rc = -EBUSY;
921 			goto out;
922 		}
923 		rio_update_route_tables(mport);
924 		rio_clear_locks(mport);
925 	} else {
926 		printk(KERN_INFO "RIO: master port %d link inactive\n",
927 		       mport->id);
928 		rc = -EINVAL;
929 	}
930 
931       out:
932 	return rc;
933 }
934 
935 /**
936  * rio_build_route_tables- Generate route tables from switch route entries
937  *
938  * For each switch device, generate a route table by copying existing
939  * route entries from the switch.
940  */
941 static void rio_build_route_tables(void)
942 {
943 	struct rio_dev *rdev;
944 	int i;
945 	u8 sport;
946 
947 	list_for_each_entry(rdev, &rio_devices, global_list)
948 	    if (rio_is_switch(rdev))
949 		for (i = 0;
950 		     i < RIO_MAX_ROUTE_ENTRIES(rdev->net->hport->sys_size);
951 		     i++) {
952 			if (rio_route_get_entry
953 			    (rdev->net->hport, rdev->rswitch, RIO_GLOBAL_TABLE,
954 			     i, &sport) < 0)
955 				continue;
956 			rdev->rswitch->route_table[i] = sport;
957 		}
958 }
959 
960 /**
961  * rio_enum_timeout- Signal that enumeration timed out
962  * @data: Address of timeout flag.
963  *
964  * When the enumeration complete timer expires, set a flag that
965  * signals to the discovery process that enumeration did not
966  * complete in a sane amount of time.
967  */
968 static void rio_enum_timeout(unsigned long data)
969 {
970 	/* Enumeration timed out, set flag */
971 	*(int *)data = 1;
972 }
973 
974 /**
975  * rio_disc_mport- Start discovery through a master port
976  * @mport: Master port to send transactions
977  *
978  * Starts the discovery process. If we have an active link,
979  * then wait for the signal that enumeration is complete.
980  * When enumeration completion is signaled, start recursive
981  * peer discovery. Returns %0 if discovery succeeds or %-EBUSY
982  * on failure.
983  */
984 int __devinit rio_disc_mport(struct rio_mport *mport)
985 {
986 	struct rio_net *net = NULL;
987 	int enum_timeout_flag = 0;
988 
989 	printk(KERN_INFO "RIO: discover master port %d, %s\n", mport->id,
990 	       mport->name);
991 
992 	/* If master port has an active link, allocate net and discover peers */
993 	if (rio_mport_is_active(mport)) {
994 		if (!(net = rio_alloc_net(mport))) {
995 			printk(KERN_ERR "RIO: Failed to allocate new net\n");
996 			goto bail;
997 		}
998 
999 		pr_debug("RIO: wait for enumeration complete...");
1000 
1001 		rio_enum_timer.expires =
1002 		    jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
1003 		rio_enum_timer.data = (unsigned long)&enum_timeout_flag;
1004 		add_timer(&rio_enum_timer);
1005 		while (!rio_enum_complete(mport)) {
1006 			mdelay(1);
1007 			if (enum_timeout_flag) {
1008 				del_timer_sync(&rio_enum_timer);
1009 				goto timeout;
1010 			}
1011 		}
1012 		del_timer_sync(&rio_enum_timer);
1013 
1014 		pr_debug("done\n");
1015 		if (rio_disc_peer(net, mport, RIO_ANY_DESTID(mport->sys_size),
1016 					0) < 0) {
1017 			printk(KERN_INFO
1018 			       "RIO: master port %d device has failed discovery\n",
1019 			       mport->id);
1020 			goto bail;
1021 		}
1022 
1023 		rio_build_route_tables();
1024 	}
1025 
1026 	return 0;
1027 
1028       timeout:
1029 	pr_debug("timeout\n");
1030       bail:
1031 	return -EBUSY;
1032 }
1033