xref: /linux/drivers/rapidio/rio-scan.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/config.h>
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 
17 #include <linux/delay.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/init.h>
20 #include <linux/rio.h>
21 #include <linux/rio_drv.h>
22 #include <linux/rio_ids.h>
23 #include <linux/rio_regs.h>
24 #include <linux/module.h>
25 #include <linux/spinlock.h>
26 #include <linux/timer.h>
27 #include <linux/jiffies.h>
28 #include <linux/slab.h>
29 
30 #include "rio.h"
31 
32 LIST_HEAD(rio_devices);
33 static LIST_HEAD(rio_switches);
34 
35 #define RIO_ENUM_CMPL_MAGIC	0xdeadbeef
36 
37 static void rio_enum_timeout(unsigned long);
38 
39 DEFINE_SPINLOCK(rio_global_list_lock);
40 
41 static int next_destid = 0;
42 static int next_switchid = 0;
43 static int next_net = 0;
44 
45 static struct timer_list rio_enum_timer =
46 TIMER_INITIALIZER(rio_enum_timeout, 0, 0);
47 
48 static int rio_mport_phys_table[] = {
49 	RIO_EFB_PAR_EP_ID,
50 	RIO_EFB_PAR_EP_REC_ID,
51 	RIO_EFB_SER_EP_ID,
52 	RIO_EFB_SER_EP_REC_ID,
53 	-1,
54 };
55 
56 static int rio_sport_phys_table[] = {
57 	RIO_EFB_PAR_EP_FREE_ID,
58 	RIO_EFB_SER_EP_FREE_ID,
59 	-1,
60 };
61 
62 /**
63  * rio_get_device_id - Get the base/extended device id for a device
64  * @port: RIO master port
65  * @destid: Destination ID of device
66  * @hopcount: Hopcount to device
67  *
68  * Reads the base/extended device id from a device. Returns the
69  * 8/16-bit device ID.
70  */
71 static u16 rio_get_device_id(struct rio_mport *port, u16 destid, u8 hopcount)
72 {
73 	u32 result;
74 
75 	rio_mport_read_config_32(port, destid, hopcount, RIO_DID_CSR, &result);
76 
77 	return RIO_GET_DID(result);
78 }
79 
80 /**
81  * rio_set_device_id - Set the base/extended device id for a device
82  * @port: RIO master port
83  * @destid: Destination ID of device
84  * @hopcount: Hopcount to device
85  * @did: Device ID value to be written
86  *
87  * Writes the base/extended device id from a device.
88  */
89 static void rio_set_device_id(struct rio_mport *port, u16 destid, u8 hopcount, u16 did)
90 {
91 	rio_mport_write_config_32(port, destid, hopcount, RIO_DID_CSR,
92 				  RIO_SET_DID(did));
93 }
94 
95 /**
96  * rio_local_set_device_id - Set the base/extended device id for a port
97  * @port: RIO master port
98  * @did: Device ID value to be written
99  *
100  * Writes the base/extended device id from a device.
101  */
102 static void rio_local_set_device_id(struct rio_mport *port, u16 did)
103 {
104 	rio_local_write_config_32(port, RIO_DID_CSR, RIO_SET_DID(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 void __devinit rio_add_device(struct rio_dev *rdev)
267 {
268 	device_add(&rdev->dev);
269 
270 	spin_lock(&rio_global_list_lock);
271 	list_add_tail(&rdev->global_list, &rio_devices);
272 	spin_unlock(&rio_global_list_lock);
273 
274 	rio_create_sysfs_dev_files(rdev);
275 }
276 
277 /**
278  * rio_setup_device- Allocates and sets up a RIO device
279  * @net: RIO network
280  * @port: Master port to send transactions
281  * @destid: Current destination ID
282  * @hopcount: Current hopcount
283  * @do_enum: Enumeration/Discovery mode flag
284  *
285  * Allocates a RIO device and configures fields based on configuration
286  * space contents. If device has a destination ID register, a destination
287  * ID is either assigned in enumeration mode or read from configuration
288  * space in discovery mode.  If the device has switch capabilities, then
289  * a switch is allocated and configured appropriately. Returns a pointer
290  * to a RIO device on success or NULL on failure.
291  *
292  */
293 static struct rio_dev *rio_setup_device(struct rio_net *net,
294 					struct rio_mport *port, u16 destid,
295 					u8 hopcount, int do_enum)
296 {
297 	struct rio_dev *rdev;
298 	struct rio_switch *rswitch;
299 	int result, rdid;
300 
301 	rdev = kmalloc(sizeof(struct rio_dev), GFP_KERNEL);
302 	if (!rdev)
303 		goto out;
304 
305 	memset(rdev, 0, sizeof(struct rio_dev));
306 	rdev->net = net;
307 	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_ID_CAR,
308 				 &result);
309 	rdev->did = result >> 16;
310 	rdev->vid = result & 0xffff;
311 	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_INFO_CAR,
312 				 &rdev->device_rev);
313 	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_ID_CAR,
314 				 &result);
315 	rdev->asm_did = result >> 16;
316 	rdev->asm_vid = result & 0xffff;
317 	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_INFO_CAR,
318 				 &result);
319 	rdev->asm_rev = result >> 16;
320 	rio_mport_read_config_32(port, destid, hopcount, RIO_PEF_CAR,
321 				 &rdev->pef);
322 	if (rdev->pef & RIO_PEF_EXT_FEATURES)
323 		rdev->efptr = result & 0xffff;
324 
325 	rio_mport_read_config_32(port, destid, hopcount, RIO_SRC_OPS_CAR,
326 				 &rdev->src_ops);
327 	rio_mport_read_config_32(port, destid, hopcount, RIO_DST_OPS_CAR,
328 				 &rdev->dst_ops);
329 
330 	if (rio_device_has_destid(port, rdev->src_ops, rdev->dst_ops)
331 	    && do_enum) {
332 		rio_set_device_id(port, destid, hopcount, next_destid);
333 		rdev->destid = next_destid++;
334 		if (next_destid == port->host_deviceid)
335 			next_destid++;
336 	} else
337 		rdev->destid = rio_get_device_id(port, destid, hopcount);
338 
339 	/* If a PE has both switch and other functions, show it as a switch */
340 	if (rio_is_switch(rdev)) {
341 		rio_mport_read_config_32(port, destid, hopcount,
342 					 RIO_SWP_INFO_CAR, &rdev->swpinfo);
343 		rswitch = kmalloc(sizeof(struct rio_switch), GFP_KERNEL);
344 		if (!rswitch) {
345 			kfree(rdev);
346 			rdev = NULL;
347 			goto out;
348 		}
349 		rswitch->switchid = next_switchid;
350 		rswitch->hopcount = hopcount;
351 		rswitch->destid = 0xffff;
352 		/* Initialize switch route table */
353 		for (rdid = 0; rdid < RIO_MAX_ROUTE_ENTRIES; rdid++)
354 			rswitch->route_table[rdid] = RIO_INVALID_ROUTE;
355 		rdev->rswitch = rswitch;
356 		sprintf(rio_name(rdev), "%02x:s:%04x", rdev->net->id,
357 			rdev->rswitch->switchid);
358 		rio_route_set_ops(rdev);
359 
360 		list_add_tail(&rswitch->node, &rio_switches);
361 
362 	} else
363 		sprintf(rio_name(rdev), "%02x:e:%04x", rdev->net->id,
364 			rdev->destid);
365 
366 	rdev->dev.bus = &rio_bus_type;
367 
368 	device_initialize(&rdev->dev);
369 	rdev->dev.release = rio_release_dev;
370 	rio_dev_get(rdev);
371 
372 	rdev->dma_mask = DMA_32BIT_MASK;
373 	rdev->dev.dma_mask = &rdev->dma_mask;
374 	rdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
375 
376 	if ((rdev->pef & RIO_PEF_INB_DOORBELL) &&
377 	    (rdev->dst_ops & RIO_DST_OPS_DOORBELL))
378 		rio_init_dbell_res(&rdev->riores[RIO_DOORBELL_RESOURCE],
379 				   0, 0xffff);
380 
381 	rio_add_device(rdev);
382 
383       out:
384 	return rdev;
385 }
386 
387 /**
388  * rio_sport_is_active- Tests if a switch port has an active connection.
389  * @port: Master port to send transaction
390  * @destid: Associated destination ID for switch
391  * @hopcount: Hopcount to reach switch
392  * @sport: Switch port number
393  *
394  * Reads the port error status CSR for a particular switch port to
395  * determine if the port has an active link.  Returns
396  * %PORT_N_ERR_STS_PORT_OK if the port is active or %0 if it is
397  * inactive.
398  */
399 static int
400 rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport)
401 {
402 	u32 result;
403 	u32 ext_ftr_ptr;
404 
405 	int *entry = rio_sport_phys_table;
406 
407 	do {
408 		if ((ext_ftr_ptr =
409 		     rio_mport_get_feature(port, 0, destid, hopcount, *entry)))
410 
411 			break;
412 	} while (*++entry >= 0);
413 
414 	if (ext_ftr_ptr)
415 		rio_mport_read_config_32(port, destid, hopcount,
416 					 ext_ftr_ptr +
417 					 RIO_PORT_N_ERR_STS_CSR(sport),
418 					 &result);
419 
420 	return (result & PORT_N_ERR_STS_PORT_OK);
421 }
422 
423 /**
424  * rio_route_add_entry- Add a route entry to a switch routing table
425  * @mport: Master port to send transaction
426  * @rdev: Switch device
427  * @table: Routing table ID
428  * @route_destid: Destination ID to be routed
429  * @route_port: Port number to be routed
430  *
431  * Calls the switch specific add_entry() method to add a route entry
432  * on a switch. The route table can be specified using the @table
433  * argument if a switch has per port routing tables or the normal
434  * use is to specific all tables (or the global table) by passing
435  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
436  * on failure.
437  */
438 static int rio_route_add_entry(struct rio_mport *mport, struct rio_dev *rdev,
439 			       u16 table, u16 route_destid, u8 route_port)
440 {
441 	return rdev->rswitch->add_entry(mport, rdev->rswitch->destid,
442 					rdev->rswitch->hopcount, table,
443 					route_destid, route_port);
444 }
445 
446 /**
447  * rio_route_get_entry- Read a route entry in a switch routing table
448  * @mport: Master port to send transaction
449  * @rdev: Switch device
450  * @table: Routing table ID
451  * @route_destid: Destination ID to be routed
452  * @route_port: Pointer to read port number into
453  *
454  * Calls the switch specific get_entry() method to read a route entry
455  * in a switch. The route table can be specified using the @table
456  * argument if a switch has per port routing tables or the normal
457  * use is to specific all tables (or the global table) by passing
458  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
459  * on failure.
460  */
461 static int
462 rio_route_get_entry(struct rio_mport *mport, struct rio_dev *rdev, u16 table,
463 		    u16 route_destid, u8 * route_port)
464 {
465 	return rdev->rswitch->get_entry(mport, rdev->rswitch->destid,
466 					rdev->rswitch->hopcount, table,
467 					route_destid, route_port);
468 }
469 
470 /**
471  * rio_get_host_deviceid_lock- Reads the Host Device ID Lock CSR on a device
472  * @port: Master port to send transaction
473  * @hopcount: Number of hops to the device
474  *
475  * Used during enumeration to read the Host Device ID Lock CSR on a
476  * RIO device. Returns the value of the lock register.
477  */
478 static u16 rio_get_host_deviceid_lock(struct rio_mport *port, u8 hopcount)
479 {
480 	u32 result;
481 
482 	rio_mport_read_config_32(port, RIO_ANY_DESTID, hopcount,
483 				 RIO_HOST_DID_LOCK_CSR, &result);
484 
485 	return (u16) (result & 0xffff);
486 }
487 
488 /**
489  * rio_get_swpinfo_inport- Gets the ingress port number
490  * @mport: Master port to send transaction
491  * @destid: Destination ID associated with the switch
492  * @hopcount: Number of hops to the device
493  *
494  * Returns port number being used to access the switch device.
495  */
496 static u8
497 rio_get_swpinfo_inport(struct rio_mport *mport, u16 destid, u8 hopcount)
498 {
499 	u32 result;
500 
501 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
502 				 &result);
503 
504 	return (u8) (result & 0xff);
505 }
506 
507 /**
508  * rio_get_swpinfo_tports- Gets total number of ports on the switch
509  * @mport: Master port to send transaction
510  * @destid: Destination ID associated with the switch
511  * @hopcount: Number of hops to the device
512  *
513  * Returns total numbers of ports implemented by the switch device.
514  */
515 static u8 rio_get_swpinfo_tports(struct rio_mport *mport, u16 destid,
516 				 u8 hopcount)
517 {
518 	u32 result;
519 
520 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
521 				 &result);
522 
523 	return RIO_GET_TOTAL_PORTS(result);
524 }
525 
526 /**
527  * rio_net_add_mport- Add a master port to a RIO network
528  * @net: RIO network
529  * @port: Master port to add
530  *
531  * Adds a master port to the network list of associated master
532  * ports..
533  */
534 static void rio_net_add_mport(struct rio_net *net, struct rio_mport *port)
535 {
536 	spin_lock(&rio_global_list_lock);
537 	list_add_tail(&port->nnode, &net->mports);
538 	spin_unlock(&rio_global_list_lock);
539 }
540 
541 /**
542  * rio_enum_peer- Recursively enumerate a RIO network through a master port
543  * @net: RIO network being enumerated
544  * @port: Master port to send transactions
545  * @hopcount: Number of hops into the network
546  *
547  * Recursively enumerates a RIO network.  Transactions are sent via the
548  * master port passed in @port.
549  */
550 static int rio_enum_peer(struct rio_net *net, struct rio_mport *port,
551 			 u8 hopcount)
552 {
553 	int port_num;
554 	int num_ports;
555 	int cur_destid;
556 	struct rio_dev *rdev;
557 	u16 destid;
558 	int tmp;
559 
560 	if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
561 		pr_debug("RIO: PE already discovered by this host\n");
562 		/*
563 		 * Already discovered by this host. Add it as another
564 		 * master port for the current network.
565 		 */
566 		rio_net_add_mport(net, port);
567 		return 0;
568 	}
569 
570 	/* Attempt to acquire device lock */
571 	rio_mport_write_config_32(port, RIO_ANY_DESTID, hopcount,
572 				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
573 	while ((tmp = rio_get_host_deviceid_lock(port, hopcount))
574 	       < port->host_deviceid) {
575 		/* Delay a bit */
576 		mdelay(1);
577 		/* Attempt to acquire device lock again */
578 		rio_mport_write_config_32(port, RIO_ANY_DESTID, hopcount,
579 					  RIO_HOST_DID_LOCK_CSR,
580 					  port->host_deviceid);
581 	}
582 
583 	if (rio_get_host_deviceid_lock(port, hopcount) > port->host_deviceid) {
584 		pr_debug(
585 		    "RIO: PE locked by a higher priority host...retreating\n");
586 		return -1;
587 	}
588 
589 	/* Setup new RIO device */
590 	if ((rdev = rio_setup_device(net, port, RIO_ANY_DESTID, hopcount, 1))) {
591 		/* Add device to the global and bus/net specific list. */
592 		list_add_tail(&rdev->net_list, &net->devices);
593 	} else
594 		return -1;
595 
596 	if (rio_is_switch(rdev)) {
597 		next_switchid++;
598 
599 		for (destid = 0; destid < next_destid; destid++) {
600 			rio_route_add_entry(port, rdev, RIO_GLOBAL_TABLE,
601 					    destid, rio_get_swpinfo_inport(port,
602 									   RIO_ANY_DESTID,
603 									   hopcount));
604 			rdev->rswitch->route_table[destid] =
605 			    rio_get_swpinfo_inport(port, RIO_ANY_DESTID,
606 						   hopcount);
607 		}
608 
609 		num_ports =
610 		    rio_get_swpinfo_tports(port, RIO_ANY_DESTID, hopcount);
611 		pr_debug(
612 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
613 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
614 		for (port_num = 0; port_num < num_ports; port_num++) {
615 			if (rio_get_swpinfo_inport
616 			    (port, RIO_ANY_DESTID, hopcount) == port_num)
617 				continue;
618 
619 			cur_destid = next_destid;
620 
621 			if (rio_sport_is_active
622 			    (port, RIO_ANY_DESTID, hopcount, port_num)) {
623 				pr_debug(
624 				    "RIO: scanning device on port %d\n",
625 				    port_num);
626 				rio_route_add_entry(port, rdev,
627 						    RIO_GLOBAL_TABLE,
628 						    RIO_ANY_DESTID, port_num);
629 
630 				if (rio_enum_peer(net, port, hopcount + 1) < 0)
631 					return -1;
632 
633 				/* Update routing tables */
634 				if (next_destid > cur_destid) {
635 					for (destid = cur_destid;
636 					     destid < next_destid; destid++) {
637 						rio_route_add_entry(port, rdev,
638 								    RIO_GLOBAL_TABLE,
639 								    destid,
640 								    port_num);
641 						rdev->rswitch->
642 						    route_table[destid] =
643 						    port_num;
644 					}
645 					rdev->rswitch->destid = cur_destid;
646 				}
647 			}
648 		}
649 	} else
650 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
651 		    rio_name(rdev), rdev->vid, rdev->did);
652 
653 	return 0;
654 }
655 
656 /**
657  * rio_enum_complete- Tests if enumeration of a network is complete
658  * @port: Master port to send transaction
659  *
660  * Tests the Component Tag CSR for presence of the magic enumeration
661  * complete flag. Return %1 if enumeration is complete or %0 if
662  * enumeration is incomplete.
663  */
664 static int rio_enum_complete(struct rio_mport *port)
665 {
666 	u32 tag_csr;
667 	int ret = 0;
668 
669 	rio_local_read_config_32(port, RIO_COMPONENT_TAG_CSR, &tag_csr);
670 
671 	if (tag_csr == RIO_ENUM_CMPL_MAGIC)
672 		ret = 1;
673 
674 	return ret;
675 }
676 
677 /**
678  * rio_disc_peer- Recursively discovers a RIO network through a master port
679  * @net: RIO network being discovered
680  * @port: Master port to send transactions
681  * @destid: Current destination ID in network
682  * @hopcount: Number of hops into the network
683  *
684  * Recursively discovers a RIO network.  Transactions are sent via the
685  * master port passed in @port.
686  */
687 static int
688 rio_disc_peer(struct rio_net *net, struct rio_mport *port, u16 destid,
689 	      u8 hopcount)
690 {
691 	u8 port_num, route_port;
692 	int num_ports;
693 	struct rio_dev *rdev;
694 	u16 ndestid;
695 
696 	/* Setup new RIO device */
697 	if ((rdev = rio_setup_device(net, port, destid, hopcount, 0))) {
698 		/* Add device to the global and bus/net specific list. */
699 		list_add_tail(&rdev->net_list, &net->devices);
700 	} else
701 		return -1;
702 
703 	if (rio_is_switch(rdev)) {
704 		next_switchid++;
705 
706 		/* Associated destid is how we accessed this switch */
707 		rdev->rswitch->destid = destid;
708 
709 		num_ports = rio_get_swpinfo_tports(port, destid, hopcount);
710 		pr_debug(
711 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
712 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
713 		for (port_num = 0; port_num < num_ports; port_num++) {
714 			if (rio_get_swpinfo_inport(port, destid, hopcount) ==
715 			    port_num)
716 				continue;
717 
718 			if (rio_sport_is_active
719 			    (port, destid, hopcount, port_num)) {
720 				pr_debug(
721 				    "RIO: scanning device on port %d\n",
722 				    port_num);
723 				for (ndestid = 0; ndestid < RIO_ANY_DESTID;
724 				     ndestid++) {
725 					rio_route_get_entry(port, rdev,
726 							    RIO_GLOBAL_TABLE,
727 							    ndestid,
728 							    &route_port);
729 					if (route_port == port_num)
730 						break;
731 				}
732 
733 				if (rio_disc_peer
734 				    (net, port, ndestid, hopcount + 1) < 0)
735 					return -1;
736 			}
737 		}
738 	} else
739 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
740 		    rio_name(rdev), rdev->vid, rdev->did);
741 
742 	return 0;
743 }
744 
745 /**
746  * rio_mport_is_active- Tests if master port link is active
747  * @port: Master port to test
748  *
749  * Reads the port error status CSR for the master port to
750  * determine if the port has an active link.  Returns
751  * %PORT_N_ERR_STS_PORT_OK if the  master port is active
752  * or %0 if it is inactive.
753  */
754 static int rio_mport_is_active(struct rio_mport *port)
755 {
756 	u32 result = 0;
757 	u32 ext_ftr_ptr;
758 	int *entry = rio_mport_phys_table;
759 
760 	do {
761 		if ((ext_ftr_ptr =
762 		     rio_mport_get_feature(port, 1, 0, 0, *entry)))
763 			break;
764 	} while (*++entry >= 0);
765 
766 	if (ext_ftr_ptr)
767 		rio_local_read_config_32(port,
768 					 ext_ftr_ptr +
769 					 RIO_PORT_N_ERR_STS_CSR(port->index),
770 					 &result);
771 
772 	return (result & PORT_N_ERR_STS_PORT_OK);
773 }
774 
775 /**
776  * rio_alloc_net- Allocate and configure a new RIO network
777  * @port: Master port associated with the RIO network
778  *
779  * Allocates a RIO network structure, initializes per-network
780  * list heads, and adds the associated master port to the
781  * network list of associated master ports. Returns a
782  * RIO network pointer on success or %NULL on failure.
783  */
784 static struct rio_net __devinit *rio_alloc_net(struct rio_mport *port)
785 {
786 	struct rio_net *net;
787 
788 	net = kmalloc(sizeof(struct rio_net), GFP_KERNEL);
789 	if (net) {
790 		memset(net, 0, sizeof(struct rio_net));
791 		INIT_LIST_HEAD(&net->node);
792 		INIT_LIST_HEAD(&net->devices);
793 		INIT_LIST_HEAD(&net->mports);
794 		list_add_tail(&port->nnode, &net->mports);
795 		net->hport = port;
796 		net->id = next_net++;
797 	}
798 	return net;
799 }
800 
801 /**
802  * rio_enum_mport- Start enumeration through a master port
803  * @mport: Master port to send transactions
804  *
805  * Starts the enumeration process. If somebody has enumerated our
806  * master port device, then give up. If not and we have an active
807  * link, then start recursive peer enumeration. Returns %0 if
808  * enumeration succeeds or %-EBUSY if enumeration fails.
809  */
810 int rio_enum_mport(struct rio_mport *mport)
811 {
812 	struct rio_net *net = NULL;
813 	int rc = 0;
814 
815 	printk(KERN_INFO "RIO: enumerate master port %d, %s\n", mport->id,
816 	       mport->name);
817 	/* If somebody else enumerated our master port device, bail. */
818 	if (rio_enum_host(mport) < 0) {
819 		printk(KERN_INFO
820 		       "RIO: master port %d device has been enumerated by a remote host\n",
821 		       mport->id);
822 		rc = -EBUSY;
823 		goto out;
824 	}
825 
826 	/* If master port has an active link, allocate net and enum peers */
827 	if (rio_mport_is_active(mport)) {
828 		if (!(net = rio_alloc_net(mport))) {
829 			printk(KERN_ERR "RIO: failed to allocate new net\n");
830 			rc = -ENOMEM;
831 			goto out;
832 		}
833 		if (rio_enum_peer(net, mport, 0) < 0) {
834 			/* A higher priority host won enumeration, bail. */
835 			printk(KERN_INFO
836 			       "RIO: master port %d device has lost enumeration to a remote host\n",
837 			       mport->id);
838 			rio_clear_locks(mport);
839 			rc = -EBUSY;
840 			goto out;
841 		}
842 		rio_clear_locks(mport);
843 	} else {
844 		printk(KERN_INFO "RIO: master port %d link inactive\n",
845 		       mport->id);
846 		rc = -EINVAL;
847 	}
848 
849       out:
850 	return rc;
851 }
852 
853 /**
854  * rio_build_route_tables- Generate route tables from switch route entries
855  *
856  * For each switch device, generate a route table by copying existing
857  * route entries from the switch.
858  */
859 static void rio_build_route_tables(void)
860 {
861 	struct rio_dev *rdev;
862 	int i;
863 	u8 sport;
864 
865 	list_for_each_entry(rdev, &rio_devices, global_list)
866 	    if (rio_is_switch(rdev))
867 		for (i = 0; i < RIO_MAX_ROUTE_ENTRIES; i++) {
868 			if (rio_route_get_entry
869 			    (rdev->net->hport, rdev, RIO_GLOBAL_TABLE, i,
870 			     &sport) < 0)
871 				continue;
872 			rdev->rswitch->route_table[i] = sport;
873 		}
874 }
875 
876 /**
877  * rio_enum_timeout- Signal that enumeration timed out
878  * @data: Address of timeout flag.
879  *
880  * When the enumeration complete timer expires, set a flag that
881  * signals to the discovery process that enumeration did not
882  * complete in a sane amount of time.
883  */
884 static void rio_enum_timeout(unsigned long data)
885 {
886 	/* Enumeration timed out, set flag */
887 	*(int *)data = 1;
888 }
889 
890 /**
891  * rio_disc_mport- Start discovery through a master port
892  * @mport: Master port to send transactions
893  *
894  * Starts the discovery process. If we have an active link,
895  * then wait for the signal that enumeration is complete.
896  * When enumeration completion is signaled, start recursive
897  * peer discovery. Returns %0 if discovery succeeds or %-EBUSY
898  * on failure.
899  */
900 int rio_disc_mport(struct rio_mport *mport)
901 {
902 	struct rio_net *net = NULL;
903 	int enum_timeout_flag = 0;
904 
905 	printk(KERN_INFO "RIO: discover master port %d, %s\n", mport->id,
906 	       mport->name);
907 
908 	/* If master port has an active link, allocate net and discover peers */
909 	if (rio_mport_is_active(mport)) {
910 		if (!(net = rio_alloc_net(mport))) {
911 			printk(KERN_ERR "RIO: Failed to allocate new net\n");
912 			goto bail;
913 		}
914 
915 		pr_debug("RIO: wait for enumeration complete...");
916 
917 		rio_enum_timer.expires =
918 		    jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
919 		rio_enum_timer.data = (unsigned long)&enum_timeout_flag;
920 		add_timer(&rio_enum_timer);
921 		while (!rio_enum_complete(mport)) {
922 			mdelay(1);
923 			if (enum_timeout_flag) {
924 				del_timer_sync(&rio_enum_timer);
925 				goto timeout;
926 			}
927 		}
928 		del_timer_sync(&rio_enum_timer);
929 
930 		pr_debug("done\n");
931 		if (rio_disc_peer(net, mport, RIO_ANY_DESTID, 0) < 0) {
932 			printk(KERN_INFO
933 			       "RIO: master port %d device has failed discovery\n",
934 			       mport->id);
935 			goto bail;
936 		}
937 
938 		rio_build_route_tables();
939 	}
940 
941 	return 0;
942 
943       timeout:
944 	pr_debug("timeout\n");
945       bail:
946 	return -EBUSY;
947 }
948