xref: /linux/drivers/rapidio/rio-scan.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
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 
28 #include "rio.h"
29 
30 LIST_HEAD(rio_devices);
31 static LIST_HEAD(rio_switches);
32 
33 #define RIO_ENUM_CMPL_MAGIC	0xdeadbeef
34 
35 static void rio_enum_timeout(unsigned long);
36 
37 DEFINE_SPINLOCK(rio_global_list_lock);
38 
39 static int next_destid = 0;
40 static int next_switchid = 0;
41 static int next_net = 0;
42 
43 static struct timer_list rio_enum_timer =
44 TIMER_INITIALIZER(rio_enum_timeout, 0, 0);
45 
46 static int rio_mport_phys_table[] = {
47 	RIO_EFB_PAR_EP_ID,
48 	RIO_EFB_PAR_EP_REC_ID,
49 	RIO_EFB_SER_EP_ID,
50 	RIO_EFB_SER_EP_REC_ID,
51 	-1,
52 };
53 
54 static int rio_sport_phys_table[] = {
55 	RIO_EFB_PAR_EP_FREE_ID,
56 	RIO_EFB_SER_EP_FREE_ID,
57 	-1,
58 };
59 
60 /**
61  * rio_get_device_id - Get the base/extended device id for a device
62  * @port: RIO master port
63  * @destid: Destination ID of device
64  * @hopcount: Hopcount to device
65  *
66  * Reads the base/extended device id from a device. Returns the
67  * 8/16-bit device ID.
68  */
69 static u16 rio_get_device_id(struct rio_mport *port, u16 destid, u8 hopcount)
70 {
71 	u32 result;
72 
73 	rio_mport_read_config_32(port, destid, hopcount, RIO_DID_CSR, &result);
74 
75 	return RIO_GET_DID(result);
76 }
77 
78 /**
79  * rio_set_device_id - Set the base/extended device id for a device
80  * @port: RIO master port
81  * @destid: Destination ID of device
82  * @hopcount: Hopcount to device
83  * @did: Device ID value to be written
84  *
85  * Writes the base/extended device id from a device.
86  */
87 static void rio_set_device_id(struct rio_mport *port, u16 destid, u8 hopcount, u16 did)
88 {
89 	rio_mport_write_config_32(port, destid, hopcount, RIO_DID_CSR,
90 				  RIO_SET_DID(did));
91 }
92 
93 /**
94  * rio_local_set_device_id - Set the base/extended device id for a port
95  * @port: RIO master port
96  * @did: Device ID value to be written
97  *
98  * Writes the base/extended device id from a device.
99  */
100 static void rio_local_set_device_id(struct rio_mport *port, u16 did)
101 {
102 	rio_local_write_config_32(port, RIO_DID_CSR, RIO_SET_DID(did));
103 }
104 
105 /**
106  * rio_clear_locks- Release all host locks and signal enumeration complete
107  * @port: Master port to issue transaction
108  *
109  * Marks the component tag CSR on each device with the enumeration
110  * complete flag. When complete, it then release the host locks on
111  * each device. Returns 0 on success or %-EINVAL on failure.
112  */
113 static int rio_clear_locks(struct rio_mport *port)
114 {
115 	struct rio_dev *rdev;
116 	u32 result;
117 	int ret = 0;
118 
119 	/* Write component tag CSR magic complete value */
120 	rio_local_write_config_32(port, RIO_COMPONENT_TAG_CSR,
121 				  RIO_ENUM_CMPL_MAGIC);
122 	list_for_each_entry(rdev, &rio_devices, global_list)
123 	    rio_write_config_32(rdev, RIO_COMPONENT_TAG_CSR,
124 				RIO_ENUM_CMPL_MAGIC);
125 
126 	/* Release host device id locks */
127 	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
128 				  port->host_deviceid);
129 	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
130 	if ((result & 0xffff) != 0xffff) {
131 		printk(KERN_INFO
132 		       "RIO: badness when releasing host lock on master port, result %8.8x\n",
133 		       result);
134 		ret = -EINVAL;
135 	}
136 	list_for_each_entry(rdev, &rio_devices, global_list) {
137 		rio_write_config_32(rdev, RIO_HOST_DID_LOCK_CSR,
138 				    port->host_deviceid);
139 		rio_read_config_32(rdev, RIO_HOST_DID_LOCK_CSR, &result);
140 		if ((result & 0xffff) != 0xffff) {
141 			printk(KERN_INFO
142 			       "RIO: badness when releasing host lock on vid %4.4x did %4.4x\n",
143 			       rdev->vid, rdev->did);
144 			ret = -EINVAL;
145 		}
146 	}
147 
148 	return ret;
149 }
150 
151 /**
152  * rio_enum_host- Set host lock and initialize host destination ID
153  * @port: Master port to issue transaction
154  *
155  * Sets the local host master port lock and destination ID register
156  * with the host device ID value. The host device ID value is provided
157  * by the platform. Returns %0 on success or %-1 on failure.
158  */
159 static int rio_enum_host(struct rio_mport *port)
160 {
161 	u32 result;
162 
163 	/* Set master port host device id lock */
164 	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
165 				  port->host_deviceid);
166 
167 	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
168 	if ((result & 0xffff) != port->host_deviceid)
169 		return -1;
170 
171 	/* Set master port destid and init destid ctr */
172 	rio_local_set_device_id(port, port->host_deviceid);
173 
174 	if (next_destid == port->host_deviceid)
175 		next_destid++;
176 
177 	return 0;
178 }
179 
180 /**
181  * rio_device_has_destid- Test if a device contains a destination ID register
182  * @port: Master port to issue transaction
183  * @src_ops: RIO device source operations
184  * @dst_ops: RIO device destination operations
185  *
186  * Checks the provided @src_ops and @dst_ops for the necessary transaction
187  * capabilities that indicate whether or not a device will implement a
188  * destination ID register. Returns 1 if true or 0 if false.
189  */
190 static int rio_device_has_destid(struct rio_mport *port, int src_ops,
191 				 int dst_ops)
192 {
193 	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;
194 
195 	return !!((src_ops | dst_ops) & mask);
196 }
197 
198 /**
199  * rio_release_dev- Frees a RIO device struct
200  * @dev: LDM device associated with a RIO device struct
201  *
202  * Gets the RIO device struct associated a RIO device struct.
203  * The RIO device struct is freed.
204  */
205 static void rio_release_dev(struct device *dev)
206 {
207 	struct rio_dev *rdev;
208 
209 	rdev = to_rio_dev(dev);
210 	kfree(rdev);
211 }
212 
213 /**
214  * rio_is_switch- Tests if a RIO device has switch capabilities
215  * @rdev: RIO device
216  *
217  * Gets the RIO device Processing Element Features register
218  * contents and tests for switch capabilities. Returns 1 if
219  * the device is a switch or 0 if it is not a switch.
220  * The RIO device struct is freed.
221  */
222 static int rio_is_switch(struct rio_dev *rdev)
223 {
224 	if (rdev->pef & RIO_PEF_SWITCH)
225 		return 1;
226 	return 0;
227 }
228 
229 /**
230  * rio_route_set_ops- Sets routing operations for a particular vendor switch
231  * @rdev: RIO device
232  *
233  * Searches the RIO route ops table for known switch types. If the vid
234  * and did match a switch table entry, then set the add_entry() and
235  * get_entry() ops to the table entry values.
236  */
237 static void rio_route_set_ops(struct rio_dev *rdev)
238 {
239 	struct rio_route_ops *cur = __start_rio_route_ops;
240 	struct rio_route_ops *end = __end_rio_route_ops;
241 
242 	while (cur < end) {
243 		if ((cur->vid == rdev->vid) && (cur->did == rdev->did)) {
244 			pr_debug("RIO: adding routing ops for %s\n", rio_name(rdev));
245 			rdev->rswitch->add_entry = cur->add_hook;
246 			rdev->rswitch->get_entry = cur->get_hook;
247 		}
248 		cur++;
249 	}
250 
251 	if (!rdev->rswitch->add_entry || !rdev->rswitch->get_entry)
252 		printk(KERN_ERR "RIO: missing routing ops for %s\n",
253 		       rio_name(rdev));
254 }
255 
256 /**
257  * rio_add_device- Adds a RIO device to the device model
258  * @rdev: RIO device
259  *
260  * Adds the RIO device to the global device list and adds the RIO
261  * device to the RIO device list.  Creates the generic sysfs nodes
262  * for an RIO device.
263  */
264 static void __devinit rio_add_device(struct rio_dev *rdev)
265 {
266 	device_add(&rdev->dev);
267 
268 	spin_lock(&rio_global_list_lock);
269 	list_add_tail(&rdev->global_list, &rio_devices);
270 	spin_unlock(&rio_global_list_lock);
271 
272 	rio_create_sysfs_dev_files(rdev);
273 }
274 
275 /**
276  * rio_setup_device- Allocates and sets up a RIO device
277  * @net: RIO network
278  * @port: Master port to send transactions
279  * @destid: Current destination ID
280  * @hopcount: Current hopcount
281  * @do_enum: Enumeration/Discovery mode flag
282  *
283  * Allocates a RIO device and configures fields based on configuration
284  * space contents. If device has a destination ID register, a destination
285  * ID is either assigned in enumeration mode or read from configuration
286  * space in discovery mode.  If the device has switch capabilities, then
287  * a switch is allocated and configured appropriately. Returns a pointer
288  * to a RIO device on success or NULL on failure.
289  *
290  */
291 static struct rio_dev *rio_setup_device(struct rio_net *net,
292 					struct rio_mport *port, u16 destid,
293 					u8 hopcount, int do_enum)
294 {
295 	struct rio_dev *rdev;
296 	struct rio_switch *rswitch;
297 	int result, rdid;
298 
299 	rdev = kmalloc(sizeof(struct rio_dev), GFP_KERNEL);
300 	if (!rdev)
301 		goto out;
302 
303 	memset(rdev, 0, sizeof(struct rio_dev));
304 	rdev->net = net;
305 	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_ID_CAR,
306 				 &result);
307 	rdev->did = result >> 16;
308 	rdev->vid = result & 0xffff;
309 	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_INFO_CAR,
310 				 &rdev->device_rev);
311 	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_ID_CAR,
312 				 &result);
313 	rdev->asm_did = result >> 16;
314 	rdev->asm_vid = result & 0xffff;
315 	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_INFO_CAR,
316 				 &result);
317 	rdev->asm_rev = result >> 16;
318 	rio_mport_read_config_32(port, destid, hopcount, RIO_PEF_CAR,
319 				 &rdev->pef);
320 	if (rdev->pef & RIO_PEF_EXT_FEATURES)
321 		rdev->efptr = result & 0xffff;
322 
323 	rio_mport_read_config_32(port, destid, hopcount, RIO_SRC_OPS_CAR,
324 				 &rdev->src_ops);
325 	rio_mport_read_config_32(port, destid, hopcount, RIO_DST_OPS_CAR,
326 				 &rdev->dst_ops);
327 
328 	if (rio_device_has_destid(port, rdev->src_ops, rdev->dst_ops)
329 	    && do_enum) {
330 		rio_set_device_id(port, destid, hopcount, next_destid);
331 		rdev->destid = next_destid++;
332 		if (next_destid == port->host_deviceid)
333 			next_destid++;
334 	} else
335 		rdev->destid = rio_get_device_id(port, destid, hopcount);
336 
337 	/* If a PE has both switch and other functions, show it as a switch */
338 	if (rio_is_switch(rdev)) {
339 		rio_mport_read_config_32(port, destid, hopcount,
340 					 RIO_SWP_INFO_CAR, &rdev->swpinfo);
341 		rswitch = kmalloc(sizeof(struct rio_switch), GFP_KERNEL);
342 		if (!rswitch) {
343 			kfree(rdev);
344 			rdev = NULL;
345 			goto out;
346 		}
347 		rswitch->switchid = next_switchid;
348 		rswitch->hopcount = hopcount;
349 		rswitch->destid = 0xffff;
350 		/* Initialize switch route table */
351 		for (rdid = 0; rdid < RIO_MAX_ROUTE_ENTRIES; rdid++)
352 			rswitch->route_table[rdid] = RIO_INVALID_ROUTE;
353 		rdev->rswitch = rswitch;
354 		sprintf(rio_name(rdev), "%02x:s:%04x", rdev->net->id,
355 			rdev->rswitch->switchid);
356 		rio_route_set_ops(rdev);
357 
358 		list_add_tail(&rswitch->node, &rio_switches);
359 
360 	} else
361 		sprintf(rio_name(rdev), "%02x:e:%04x", rdev->net->id,
362 			rdev->destid);
363 
364 	rdev->dev.bus = &rio_bus_type;
365 
366 	device_initialize(&rdev->dev);
367 	rdev->dev.release = rio_release_dev;
368 	rio_dev_get(rdev);
369 
370 	rdev->dma_mask = DMA_32BIT_MASK;
371 	rdev->dev.dma_mask = &rdev->dma_mask;
372 	rdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
373 
374 	if ((rdev->pef & RIO_PEF_INB_DOORBELL) &&
375 	    (rdev->dst_ops & RIO_DST_OPS_DOORBELL))
376 		rio_init_dbell_res(&rdev->riores[RIO_DOORBELL_RESOURCE],
377 				   0, 0xffff);
378 
379 	rio_add_device(rdev);
380 
381       out:
382 	return rdev;
383 }
384 
385 /**
386  * rio_sport_is_active- Tests if a switch port has an active connection.
387  * @port: Master port to send transaction
388  * @destid: Associated destination ID for switch
389  * @hopcount: Hopcount to reach switch
390  * @sport: Switch port number
391  *
392  * Reads the port error status CSR for a particular switch port to
393  * determine if the port has an active link.  Returns
394  * %PORT_N_ERR_STS_PORT_OK if the port is active or %0 if it is
395  * inactive.
396  */
397 static int
398 rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport)
399 {
400 	u32 result;
401 	u32 ext_ftr_ptr;
402 
403 	int *entry = rio_sport_phys_table;
404 
405 	do {
406 		if ((ext_ftr_ptr =
407 		     rio_mport_get_feature(port, 0, destid, hopcount, *entry)))
408 
409 			break;
410 	} while (*++entry >= 0);
411 
412 	if (ext_ftr_ptr)
413 		rio_mport_read_config_32(port, destid, hopcount,
414 					 ext_ftr_ptr +
415 					 RIO_PORT_N_ERR_STS_CSR(sport),
416 					 &result);
417 
418 	return (result & PORT_N_ERR_STS_PORT_OK);
419 }
420 
421 /**
422  * rio_route_add_entry- Add a route entry to a switch routing table
423  * @mport: Master port to send transaction
424  * @rdev: Switch device
425  * @table: Routing table ID
426  * @route_destid: Destination ID to be routed
427  * @route_port: Port number to be routed
428  *
429  * Calls the switch specific add_entry() method to add a route entry
430  * on a switch. The route table can be specified using the @table
431  * argument if a switch has per port routing tables or the normal
432  * use is to specific all tables (or the global table) by passing
433  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
434  * on failure.
435  */
436 static int rio_route_add_entry(struct rio_mport *mport, struct rio_dev *rdev,
437 			       u16 table, u16 route_destid, u8 route_port)
438 {
439 	return rdev->rswitch->add_entry(mport, rdev->rswitch->destid,
440 					rdev->rswitch->hopcount, table,
441 					route_destid, route_port);
442 }
443 
444 /**
445  * rio_route_get_entry- Read a route entry in a switch routing table
446  * @mport: Master port to send transaction
447  * @rdev: Switch device
448  * @table: Routing table ID
449  * @route_destid: Destination ID to be routed
450  * @route_port: Pointer to read port number into
451  *
452  * Calls the switch specific get_entry() method to read a route entry
453  * in 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
460 rio_route_get_entry(struct rio_mport *mport, struct rio_dev *rdev, u16 table,
461 		    u16 route_destid, u8 * route_port)
462 {
463 	return rdev->rswitch->get_entry(mport, rdev->rswitch->destid,
464 					rdev->rswitch->hopcount, table,
465 					route_destid, route_port);
466 }
467 
468 /**
469  * rio_get_host_deviceid_lock- Reads the Host Device ID Lock CSR on a device
470  * @port: Master port to send transaction
471  * @hopcount: Number of hops to the device
472  *
473  * Used during enumeration to read the Host Device ID Lock CSR on a
474  * RIO device. Returns the value of the lock register.
475  */
476 static u16 rio_get_host_deviceid_lock(struct rio_mport *port, u8 hopcount)
477 {
478 	u32 result;
479 
480 	rio_mport_read_config_32(port, RIO_ANY_DESTID, hopcount,
481 				 RIO_HOST_DID_LOCK_CSR, &result);
482 
483 	return (u16) (result & 0xffff);
484 }
485 
486 /**
487  * rio_get_swpinfo_inport- Gets the ingress port number
488  * @mport: Master port to send transaction
489  * @destid: Destination ID associated with the switch
490  * @hopcount: Number of hops to the device
491  *
492  * Returns port number being used to access the switch device.
493  */
494 static u8
495 rio_get_swpinfo_inport(struct rio_mport *mport, u16 destid, u8 hopcount)
496 {
497 	u32 result;
498 
499 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
500 				 &result);
501 
502 	return (u8) (result & 0xff);
503 }
504 
505 /**
506  * rio_get_swpinfo_tports- Gets total number of ports on the switch
507  * @mport: Master port to send transaction
508  * @destid: Destination ID associated with the switch
509  * @hopcount: Number of hops to the device
510  *
511  * Returns total numbers of ports implemented by the switch device.
512  */
513 static u8 rio_get_swpinfo_tports(struct rio_mport *mport, u16 destid,
514 				 u8 hopcount)
515 {
516 	u32 result;
517 
518 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
519 				 &result);
520 
521 	return RIO_GET_TOTAL_PORTS(result);
522 }
523 
524 /**
525  * rio_net_add_mport- Add a master port to a RIO network
526  * @net: RIO network
527  * @port: Master port to add
528  *
529  * Adds a master port to the network list of associated master
530  * ports..
531  */
532 static void rio_net_add_mport(struct rio_net *net, struct rio_mport *port)
533 {
534 	spin_lock(&rio_global_list_lock);
535 	list_add_tail(&port->nnode, &net->mports);
536 	spin_unlock(&rio_global_list_lock);
537 }
538 
539 /**
540  * rio_enum_peer- Recursively enumerate a RIO network through a master port
541  * @net: RIO network being enumerated
542  * @port: Master port to send transactions
543  * @hopcount: Number of hops into the network
544  *
545  * Recursively enumerates a RIO network.  Transactions are sent via the
546  * master port passed in @port.
547  */
548 static int rio_enum_peer(struct rio_net *net, struct rio_mport *port,
549 			 u8 hopcount)
550 {
551 	int port_num;
552 	int num_ports;
553 	int cur_destid;
554 	struct rio_dev *rdev;
555 	u16 destid;
556 	int tmp;
557 
558 	if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
559 		pr_debug("RIO: PE already discovered by this host\n");
560 		/*
561 		 * Already discovered by this host. Add it as another
562 		 * master port for the current network.
563 		 */
564 		rio_net_add_mport(net, port);
565 		return 0;
566 	}
567 
568 	/* Attempt to acquire device lock */
569 	rio_mport_write_config_32(port, RIO_ANY_DESTID, hopcount,
570 				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
571 	while ((tmp = rio_get_host_deviceid_lock(port, hopcount))
572 	       < port->host_deviceid) {
573 		/* Delay a bit */
574 		mdelay(1);
575 		/* Attempt to acquire device lock again */
576 		rio_mport_write_config_32(port, RIO_ANY_DESTID, hopcount,
577 					  RIO_HOST_DID_LOCK_CSR,
578 					  port->host_deviceid);
579 	}
580 
581 	if (rio_get_host_deviceid_lock(port, hopcount) > port->host_deviceid) {
582 		pr_debug(
583 		    "RIO: PE locked by a higher priority host...retreating\n");
584 		return -1;
585 	}
586 
587 	/* Setup new RIO device */
588 	if ((rdev = rio_setup_device(net, port, RIO_ANY_DESTID, hopcount, 1))) {
589 		/* Add device to the global and bus/net specific list. */
590 		list_add_tail(&rdev->net_list, &net->devices);
591 	} else
592 		return -1;
593 
594 	if (rio_is_switch(rdev)) {
595 		next_switchid++;
596 
597 		for (destid = 0; destid < next_destid; destid++) {
598 			rio_route_add_entry(port, rdev, RIO_GLOBAL_TABLE,
599 					    destid, rio_get_swpinfo_inport(port,
600 									   RIO_ANY_DESTID,
601 									   hopcount));
602 			rdev->rswitch->route_table[destid] =
603 			    rio_get_swpinfo_inport(port, RIO_ANY_DESTID,
604 						   hopcount);
605 		}
606 
607 		num_ports =
608 		    rio_get_swpinfo_tports(port, RIO_ANY_DESTID, hopcount);
609 		pr_debug(
610 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
611 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
612 		for (port_num = 0; port_num < num_ports; port_num++) {
613 			if (rio_get_swpinfo_inport
614 			    (port, RIO_ANY_DESTID, hopcount) == port_num)
615 				continue;
616 
617 			cur_destid = next_destid;
618 
619 			if (rio_sport_is_active
620 			    (port, RIO_ANY_DESTID, hopcount, port_num)) {
621 				pr_debug(
622 				    "RIO: scanning device on port %d\n",
623 				    port_num);
624 				rio_route_add_entry(port, rdev,
625 						    RIO_GLOBAL_TABLE,
626 						    RIO_ANY_DESTID, port_num);
627 
628 				if (rio_enum_peer(net, port, hopcount + 1) < 0)
629 					return -1;
630 
631 				/* Update routing tables */
632 				if (next_destid > cur_destid) {
633 					for (destid = cur_destid;
634 					     destid < next_destid; destid++) {
635 						rio_route_add_entry(port, rdev,
636 								    RIO_GLOBAL_TABLE,
637 								    destid,
638 								    port_num);
639 						rdev->rswitch->
640 						    route_table[destid] =
641 						    port_num;
642 					}
643 					rdev->rswitch->destid = cur_destid;
644 				}
645 			}
646 		}
647 	} else
648 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
649 		    rio_name(rdev), rdev->vid, rdev->did);
650 
651 	return 0;
652 }
653 
654 /**
655  * rio_enum_complete- Tests if enumeration of a network is complete
656  * @port: Master port to send transaction
657  *
658  * Tests the Component Tag CSR for presence of the magic enumeration
659  * complete flag. Return %1 if enumeration is complete or %0 if
660  * enumeration is incomplete.
661  */
662 static int rio_enum_complete(struct rio_mport *port)
663 {
664 	u32 tag_csr;
665 	int ret = 0;
666 
667 	rio_local_read_config_32(port, RIO_COMPONENT_TAG_CSR, &tag_csr);
668 
669 	if (tag_csr == RIO_ENUM_CMPL_MAGIC)
670 		ret = 1;
671 
672 	return ret;
673 }
674 
675 /**
676  * rio_disc_peer- Recursively discovers a RIO network through a master port
677  * @net: RIO network being discovered
678  * @port: Master port to send transactions
679  * @destid: Current destination ID in network
680  * @hopcount: Number of hops into the network
681  *
682  * Recursively discovers a RIO network.  Transactions are sent via the
683  * master port passed in @port.
684  */
685 static int
686 rio_disc_peer(struct rio_net *net, struct rio_mport *port, u16 destid,
687 	      u8 hopcount)
688 {
689 	u8 port_num, route_port;
690 	int num_ports;
691 	struct rio_dev *rdev;
692 	u16 ndestid;
693 
694 	/* Setup new RIO device */
695 	if ((rdev = rio_setup_device(net, port, destid, hopcount, 0))) {
696 		/* Add device to the global and bus/net specific list. */
697 		list_add_tail(&rdev->net_list, &net->devices);
698 	} else
699 		return -1;
700 
701 	if (rio_is_switch(rdev)) {
702 		next_switchid++;
703 
704 		/* Associated destid is how we accessed this switch */
705 		rdev->rswitch->destid = destid;
706 
707 		num_ports = rio_get_swpinfo_tports(port, destid, hopcount);
708 		pr_debug(
709 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
710 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
711 		for (port_num = 0; port_num < num_ports; port_num++) {
712 			if (rio_get_swpinfo_inport(port, destid, hopcount) ==
713 			    port_num)
714 				continue;
715 
716 			if (rio_sport_is_active
717 			    (port, destid, hopcount, port_num)) {
718 				pr_debug(
719 				    "RIO: scanning device on port %d\n",
720 				    port_num);
721 				for (ndestid = 0; ndestid < RIO_ANY_DESTID;
722 				     ndestid++) {
723 					rio_route_get_entry(port, rdev,
724 							    RIO_GLOBAL_TABLE,
725 							    ndestid,
726 							    &route_port);
727 					if (route_port == port_num)
728 						break;
729 				}
730 
731 				if (rio_disc_peer
732 				    (net, port, ndestid, hopcount + 1) < 0)
733 					return -1;
734 			}
735 		}
736 	} else
737 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
738 		    rio_name(rdev), rdev->vid, rdev->did);
739 
740 	return 0;
741 }
742 
743 /**
744  * rio_mport_is_active- Tests if master port link is active
745  * @port: Master port to test
746  *
747  * Reads the port error status CSR for the master port to
748  * determine if the port has an active link.  Returns
749  * %PORT_N_ERR_STS_PORT_OK if the  master port is active
750  * or %0 if it is inactive.
751  */
752 static int rio_mport_is_active(struct rio_mport *port)
753 {
754 	u32 result = 0;
755 	u32 ext_ftr_ptr;
756 	int *entry = rio_mport_phys_table;
757 
758 	do {
759 		if ((ext_ftr_ptr =
760 		     rio_mport_get_feature(port, 1, 0, 0, *entry)))
761 			break;
762 	} while (*++entry >= 0);
763 
764 	if (ext_ftr_ptr)
765 		rio_local_read_config_32(port,
766 					 ext_ftr_ptr +
767 					 RIO_PORT_N_ERR_STS_CSR(port->index),
768 					 &result);
769 
770 	return (result & PORT_N_ERR_STS_PORT_OK);
771 }
772 
773 /**
774  * rio_alloc_net- Allocate and configure a new RIO network
775  * @port: Master port associated with the RIO network
776  *
777  * Allocates a RIO network structure, initializes per-network
778  * list heads, and adds the associated master port to the
779  * network list of associated master ports. Returns a
780  * RIO network pointer on success or %NULL on failure.
781  */
782 static struct rio_net __devinit *rio_alloc_net(struct rio_mport *port)
783 {
784 	struct rio_net *net;
785 
786 	net = kmalloc(sizeof(struct rio_net), GFP_KERNEL);
787 	if (net) {
788 		memset(net, 0, sizeof(struct rio_net));
789 		INIT_LIST_HEAD(&net->node);
790 		INIT_LIST_HEAD(&net->devices);
791 		INIT_LIST_HEAD(&net->mports);
792 		list_add_tail(&port->nnode, &net->mports);
793 		net->hport = port;
794 		net->id = next_net++;
795 	}
796 	return net;
797 }
798 
799 /**
800  * rio_enum_mport- Start enumeration through a master port
801  * @mport: Master port to send transactions
802  *
803  * Starts the enumeration process. If somebody has enumerated our
804  * master port device, then give up. If not and we have an active
805  * link, then start recursive peer enumeration. Returns %0 if
806  * enumeration succeeds or %-EBUSY if enumeration fails.
807  */
808 int rio_enum_mport(struct rio_mport *mport)
809 {
810 	struct rio_net *net = NULL;
811 	int rc = 0;
812 
813 	printk(KERN_INFO "RIO: enumerate master port %d, %s\n", mport->id,
814 	       mport->name);
815 	/* If somebody else enumerated our master port device, bail. */
816 	if (rio_enum_host(mport) < 0) {
817 		printk(KERN_INFO
818 		       "RIO: master port %d device has been enumerated by a remote host\n",
819 		       mport->id);
820 		rc = -EBUSY;
821 		goto out;
822 	}
823 
824 	/* If master port has an active link, allocate net and enum peers */
825 	if (rio_mport_is_active(mport)) {
826 		if (!(net = rio_alloc_net(mport))) {
827 			printk(KERN_ERR "RIO: failed to allocate new net\n");
828 			rc = -ENOMEM;
829 			goto out;
830 		}
831 		if (rio_enum_peer(net, mport, 0) < 0) {
832 			/* A higher priority host won enumeration, bail. */
833 			printk(KERN_INFO
834 			       "RIO: master port %d device has lost enumeration to a remote host\n",
835 			       mport->id);
836 			rio_clear_locks(mport);
837 			rc = -EBUSY;
838 			goto out;
839 		}
840 		rio_clear_locks(mport);
841 	} else {
842 		printk(KERN_INFO "RIO: master port %d link inactive\n",
843 		       mport->id);
844 		rc = -EINVAL;
845 	}
846 
847       out:
848 	return rc;
849 }
850 
851 /**
852  * rio_build_route_tables- Generate route tables from switch route entries
853  *
854  * For each switch device, generate a route table by copying existing
855  * route entries from the switch.
856  */
857 static void rio_build_route_tables(void)
858 {
859 	struct rio_dev *rdev;
860 	int i;
861 	u8 sport;
862 
863 	list_for_each_entry(rdev, &rio_devices, global_list)
864 	    if (rio_is_switch(rdev))
865 		for (i = 0; i < RIO_MAX_ROUTE_ENTRIES; i++) {
866 			if (rio_route_get_entry
867 			    (rdev->net->hport, rdev, RIO_GLOBAL_TABLE, i,
868 			     &sport) < 0)
869 				continue;
870 			rdev->rswitch->route_table[i] = sport;
871 		}
872 }
873 
874 /**
875  * rio_enum_timeout- Signal that enumeration timed out
876  * @data: Address of timeout flag.
877  *
878  * When the enumeration complete timer expires, set a flag that
879  * signals to the discovery process that enumeration did not
880  * complete in a sane amount of time.
881  */
882 static void rio_enum_timeout(unsigned long data)
883 {
884 	/* Enumeration timed out, set flag */
885 	*(int *)data = 1;
886 }
887 
888 /**
889  * rio_disc_mport- Start discovery through a master port
890  * @mport: Master port to send transactions
891  *
892  * Starts the discovery process. If we have an active link,
893  * then wait for the signal that enumeration is complete.
894  * When enumeration completion is signaled, start recursive
895  * peer discovery. Returns %0 if discovery succeeds or %-EBUSY
896  * on failure.
897  */
898 int rio_disc_mport(struct rio_mport *mport)
899 {
900 	struct rio_net *net = NULL;
901 	int enum_timeout_flag = 0;
902 
903 	printk(KERN_INFO "RIO: discover master port %d, %s\n", mport->id,
904 	       mport->name);
905 
906 	/* If master port has an active link, allocate net and discover peers */
907 	if (rio_mport_is_active(mport)) {
908 		if (!(net = rio_alloc_net(mport))) {
909 			printk(KERN_ERR "RIO: Failed to allocate new net\n");
910 			goto bail;
911 		}
912 
913 		pr_debug("RIO: wait for enumeration complete...");
914 
915 		rio_enum_timer.expires =
916 		    jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
917 		rio_enum_timer.data = (unsigned long)&enum_timeout_flag;
918 		add_timer(&rio_enum_timer);
919 		while (!rio_enum_complete(mport)) {
920 			mdelay(1);
921 			if (enum_timeout_flag) {
922 				del_timer_sync(&rio_enum_timer);
923 				goto timeout;
924 			}
925 		}
926 		del_timer_sync(&rio_enum_timer);
927 
928 		pr_debug("done\n");
929 		if (rio_disc_peer(net, mport, RIO_ANY_DESTID, 0) < 0) {
930 			printk(KERN_INFO
931 			       "RIO: master port %d device has failed discovery\n",
932 			       mport->id);
933 			goto bail;
934 		}
935 
936 		rio_build_route_tables();
937 	}
938 
939 	return 0;
940 
941       timeout:
942 	pr_debug("timeout\n");
943       bail:
944 	return -EBUSY;
945 }
946