xref: /openbmc/linux/drivers/rapidio/rio-scan.c (revision 384740dc)
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 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 = kzalloc(sizeof(struct rio_dev), GFP_KERNEL);
302 	if (!rdev)
303 		goto out;
304 
305 	rdev->net = net;
306 	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_ID_CAR,
307 				 &result);
308 	rdev->did = result >> 16;
309 	rdev->vid = result & 0xffff;
310 	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_INFO_CAR,
311 				 &rdev->device_rev);
312 	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_ID_CAR,
313 				 &result);
314 	rdev->asm_did = result >> 16;
315 	rdev->asm_vid = result & 0xffff;
316 	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_INFO_CAR,
317 				 &result);
318 	rdev->asm_rev = result >> 16;
319 	rio_mport_read_config_32(port, destid, hopcount, RIO_PEF_CAR,
320 				 &rdev->pef);
321 	if (rdev->pef & RIO_PEF_EXT_FEATURES)
322 		rdev->efptr = result & 0xffff;
323 
324 	rio_mport_read_config_32(port, destid, hopcount, RIO_SRC_OPS_CAR,
325 				 &rdev->src_ops);
326 	rio_mport_read_config_32(port, destid, hopcount, RIO_DST_OPS_CAR,
327 				 &rdev->dst_ops);
328 
329 	if (rio_device_has_destid(port, rdev->src_ops, rdev->dst_ops)) {
330 		if (do_enum) {
331 			rio_set_device_id(port, destid, hopcount, next_destid);
332 			rdev->destid = next_destid++;
333 			if (next_destid == port->host_deviceid)
334 				next_destid++;
335 		} else
336 			rdev->destid = rio_get_device_id(port, destid, hopcount);
337 	} else
338 		/* Switch device has an associated destID */
339 		rdev->destid = RIO_INVALID_DESTID;
340 
341 	/* If a PE has both switch and other functions, show it as a switch */
342 	if (rio_is_switch(rdev)) {
343 		rio_mport_read_config_32(port, destid, hopcount,
344 					 RIO_SWP_INFO_CAR, &rdev->swpinfo);
345 		rswitch = kmalloc(sizeof(struct rio_switch), GFP_KERNEL);
346 		if (!rswitch) {
347 			kfree(rdev);
348 			rdev = NULL;
349 			goto out;
350 		}
351 		rswitch->switchid = next_switchid;
352 		rswitch->hopcount = hopcount;
353 		rswitch->destid = destid;
354 		rswitch->route_table = kzalloc(sizeof(u8)*
355 					RIO_MAX_ROUTE_ENTRIES(port->sys_size),
356 					GFP_KERNEL);
357 		if (!rswitch->route_table) {
358 			kfree(rdev);
359 			rdev = NULL;
360 			kfree(rswitch);
361 			goto out;
362 		}
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 		sprintf(rio_name(rdev), "%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 		sprintf(rio_name(rdev), "%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_32BIT_MASK;
385 	rdev->dev.dma_mask = &rdev->dma_mask;
386 	rdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
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 	rio_add_device(rdev);
394 
395       out:
396 	return rdev;
397 }
398 
399 /**
400  * rio_sport_is_active- Tests if a switch port has an active connection.
401  * @port: Master port to send transaction
402  * @destid: Associated destination ID for switch
403  * @hopcount: Hopcount to reach switch
404  * @sport: Switch port number
405  *
406  * Reads the port error status CSR for a particular switch port to
407  * determine if the port has an active link.  Returns
408  * %PORT_N_ERR_STS_PORT_OK if the port is active or %0 if it is
409  * inactive.
410  */
411 static int
412 rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport)
413 {
414 	u32 result;
415 	u32 ext_ftr_ptr;
416 
417 	int *entry = rio_sport_phys_table;
418 
419 	do {
420 		if ((ext_ftr_ptr =
421 		     rio_mport_get_feature(port, 0, destid, hopcount, *entry)))
422 
423 			break;
424 	} while (*++entry >= 0);
425 
426 	if (ext_ftr_ptr)
427 		rio_mport_read_config_32(port, destid, hopcount,
428 					 ext_ftr_ptr +
429 					 RIO_PORT_N_ERR_STS_CSR(sport),
430 					 &result);
431 
432 	return (result & PORT_N_ERR_STS_PORT_OK);
433 }
434 
435 /**
436  * rio_route_add_entry- Add a route entry to a switch routing table
437  * @mport: Master port to send transaction
438  * @rswitch: Switch device
439  * @table: Routing table ID
440  * @route_destid: Destination ID to be routed
441  * @route_port: Port number to be routed
442  *
443  * Calls the switch specific add_entry() method to add a route entry
444  * on a switch. The route table can be specified using the @table
445  * argument if a switch has per port routing tables or the normal
446  * use is to specific all tables (or the global table) by passing
447  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
448  * on failure.
449  */
450 static int rio_route_add_entry(struct rio_mport *mport, struct rio_switch *rswitch,
451 			       u16 table, u16 route_destid, u8 route_port)
452 {
453 	return rswitch->add_entry(mport, rswitch->destid,
454 					rswitch->hopcount, table,
455 					route_destid, route_port);
456 }
457 
458 /**
459  * rio_route_get_entry- Read a route entry in a switch routing table
460  * @mport: Master port to send transaction
461  * @rswitch: Switch device
462  * @table: Routing table ID
463  * @route_destid: Destination ID to be routed
464  * @route_port: Pointer to read port number into
465  *
466  * Calls the switch specific get_entry() method to read a route entry
467  * in a switch. The route table can be specified using the @table
468  * argument if a switch has per port routing tables or the normal
469  * use is to specific all tables (or the global table) by passing
470  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
471  * on failure.
472  */
473 static int
474 rio_route_get_entry(struct rio_mport *mport, struct rio_switch *rswitch, u16 table,
475 		    u16 route_destid, u8 * route_port)
476 {
477 	return rswitch->get_entry(mport, rswitch->destid,
478 					rswitch->hopcount, table,
479 					route_destid, route_port);
480 }
481 
482 /**
483  * rio_get_host_deviceid_lock- Reads the Host Device ID Lock CSR on a device
484  * @port: Master port to send transaction
485  * @hopcount: Number of hops to the device
486  *
487  * Used during enumeration to read the Host Device ID Lock CSR on a
488  * RIO device. Returns the value of the lock register.
489  */
490 static u16 rio_get_host_deviceid_lock(struct rio_mport *port, u8 hopcount)
491 {
492 	u32 result;
493 
494 	rio_mport_read_config_32(port, RIO_ANY_DESTID(port->sys_size), hopcount,
495 				 RIO_HOST_DID_LOCK_CSR, &result);
496 
497 	return (u16) (result & 0xffff);
498 }
499 
500 /**
501  * rio_get_swpinfo_inport- Gets the ingress port number
502  * @mport: Master port to send transaction
503  * @destid: Destination ID associated with the switch
504  * @hopcount: Number of hops to the device
505  *
506  * Returns port number being used to access the switch device.
507  */
508 static u8
509 rio_get_swpinfo_inport(struct rio_mport *mport, u16 destid, u8 hopcount)
510 {
511 	u32 result;
512 
513 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
514 				 &result);
515 
516 	return (u8) (result & 0xff);
517 }
518 
519 /**
520  * rio_get_swpinfo_tports- Gets total number of ports on the switch
521  * @mport: Master port to send transaction
522  * @destid: Destination ID associated with the switch
523  * @hopcount: Number of hops to the device
524  *
525  * Returns total numbers of ports implemented by the switch device.
526  */
527 static u8 rio_get_swpinfo_tports(struct rio_mport *mport, u16 destid,
528 				 u8 hopcount)
529 {
530 	u32 result;
531 
532 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
533 				 &result);
534 
535 	return RIO_GET_TOTAL_PORTS(result);
536 }
537 
538 /**
539  * rio_net_add_mport- Add a master port to a RIO network
540  * @net: RIO network
541  * @port: Master port to add
542  *
543  * Adds a master port to the network list of associated master
544  * ports..
545  */
546 static void rio_net_add_mport(struct rio_net *net, struct rio_mport *port)
547 {
548 	spin_lock(&rio_global_list_lock);
549 	list_add_tail(&port->nnode, &net->mports);
550 	spin_unlock(&rio_global_list_lock);
551 }
552 
553 /**
554  * rio_enum_peer- Recursively enumerate a RIO network through a master port
555  * @net: RIO network being enumerated
556  * @port: Master port to send transactions
557  * @hopcount: Number of hops into the network
558  *
559  * Recursively enumerates a RIO network.  Transactions are sent via the
560  * master port passed in @port.
561  */
562 static int rio_enum_peer(struct rio_net *net, struct rio_mport *port,
563 			 u8 hopcount)
564 {
565 	int port_num;
566 	int num_ports;
567 	int cur_destid;
568 	int sw_destid;
569 	int sw_inport;
570 	struct rio_dev *rdev;
571 	u16 destid;
572 	int tmp;
573 
574 	if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
575 		pr_debug("RIO: PE already discovered by this host\n");
576 		/*
577 		 * Already discovered by this host. Add it as another
578 		 * master port for the current network.
579 		 */
580 		rio_net_add_mport(net, port);
581 		return 0;
582 	}
583 
584 	/* Attempt to acquire device lock */
585 	rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
586 				  hopcount,
587 				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
588 	while ((tmp = rio_get_host_deviceid_lock(port, hopcount))
589 	       < port->host_deviceid) {
590 		/* Delay a bit */
591 		mdelay(1);
592 		/* Attempt to acquire device lock again */
593 		rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
594 					  hopcount,
595 					  RIO_HOST_DID_LOCK_CSR,
596 					  port->host_deviceid);
597 	}
598 
599 	if (rio_get_host_deviceid_lock(port, hopcount) > port->host_deviceid) {
600 		pr_debug(
601 		    "RIO: PE locked by a higher priority host...retreating\n");
602 		return -1;
603 	}
604 
605 	/* Setup new RIO device */
606 	rdev = rio_setup_device(net, port, RIO_ANY_DESTID(port->sys_size),
607 					hopcount, 1);
608 	if (rdev) {
609 		/* Add device to the global and bus/net specific list. */
610 		list_add_tail(&rdev->net_list, &net->devices);
611 	} else
612 		return -1;
613 
614 	if (rio_is_switch(rdev)) {
615 		next_switchid++;
616 		sw_inport = rio_get_swpinfo_inport(port,
617 				RIO_ANY_DESTID(port->sys_size), hopcount);
618 		rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,
619 				    port->host_deviceid, sw_inport);
620 		rdev->rswitch->route_table[port->host_deviceid] = sw_inport;
621 
622 		for (destid = 0; destid < next_destid; destid++) {
623 			if (destid == port->host_deviceid)
624 				continue;
625 			rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,
626 					    destid, sw_inport);
627 			rdev->rswitch->route_table[destid] = sw_inport;
628 		}
629 
630 		num_ports =
631 		    rio_get_swpinfo_tports(port, RIO_ANY_DESTID(port->sys_size),
632 						hopcount);
633 		pr_debug(
634 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
635 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
636 		sw_destid = next_destid;
637 		for (port_num = 0; port_num < num_ports; port_num++) {
638 			if (sw_inport == port_num)
639 				continue;
640 
641 			cur_destid = next_destid;
642 
643 			if (rio_sport_is_active
644 			    (port, RIO_ANY_DESTID(port->sys_size), hopcount,
645 			     port_num)) {
646 				pr_debug(
647 				    "RIO: scanning device on port %d\n",
648 				    port_num);
649 				rio_route_add_entry(port, rdev->rswitch,
650 						RIO_GLOBAL_TABLE,
651 						RIO_ANY_DESTID(port->sys_size),
652 						port_num);
653 
654 				if (rio_enum_peer(net, port, hopcount + 1) < 0)
655 					return -1;
656 
657 				/* Update routing tables */
658 				if (next_destid > cur_destid) {
659 					for (destid = cur_destid;
660 					     destid < next_destid; destid++) {
661 						if (destid == port->host_deviceid)
662 							continue;
663 						rio_route_add_entry(port, rdev->rswitch,
664 								    RIO_GLOBAL_TABLE,
665 								    destid,
666 								    port_num);
667 						rdev->rswitch->
668 						    route_table[destid] =
669 						    port_num;
670 					}
671 				}
672 			}
673 		}
674 
675 		/* Check for empty switch */
676 		if (next_destid == sw_destid) {
677 			next_destid++;
678 			if (next_destid == port->host_deviceid)
679 				next_destid++;
680 		}
681 
682 		rdev->rswitch->destid = sw_destid;
683 	} else
684 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
685 		    rio_name(rdev), rdev->vid, rdev->did);
686 
687 	return 0;
688 }
689 
690 /**
691  * rio_enum_complete- Tests if enumeration of a network is complete
692  * @port: Master port to send transaction
693  *
694  * Tests the Component Tag CSR for presence of the magic enumeration
695  * complete flag. Return %1 if enumeration is complete or %0 if
696  * enumeration is incomplete.
697  */
698 static int rio_enum_complete(struct rio_mport *port)
699 {
700 	u32 tag_csr;
701 	int ret = 0;
702 
703 	rio_local_read_config_32(port, RIO_COMPONENT_TAG_CSR, &tag_csr);
704 
705 	if (tag_csr == RIO_ENUM_CMPL_MAGIC)
706 		ret = 1;
707 
708 	return ret;
709 }
710 
711 /**
712  * rio_disc_peer- Recursively discovers a RIO network through a master port
713  * @net: RIO network being discovered
714  * @port: Master port to send transactions
715  * @destid: Current destination ID in network
716  * @hopcount: Number of hops into the network
717  *
718  * Recursively discovers a RIO network.  Transactions are sent via the
719  * master port passed in @port.
720  */
721 static int
722 rio_disc_peer(struct rio_net *net, struct rio_mport *port, u16 destid,
723 	      u8 hopcount)
724 {
725 	u8 port_num, route_port;
726 	int num_ports;
727 	struct rio_dev *rdev;
728 	u16 ndestid;
729 
730 	/* Setup new RIO device */
731 	if ((rdev = rio_setup_device(net, port, destid, hopcount, 0))) {
732 		/* Add device to the global and bus/net specific list. */
733 		list_add_tail(&rdev->net_list, &net->devices);
734 	} else
735 		return -1;
736 
737 	if (rio_is_switch(rdev)) {
738 		next_switchid++;
739 
740 		/* Associated destid is how we accessed this switch */
741 		rdev->rswitch->destid = destid;
742 
743 		num_ports = rio_get_swpinfo_tports(port, destid, hopcount);
744 		pr_debug(
745 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
746 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
747 		for (port_num = 0; port_num < num_ports; port_num++) {
748 			if (rio_get_swpinfo_inport(port, destid, hopcount) ==
749 			    port_num)
750 				continue;
751 
752 			if (rio_sport_is_active
753 			    (port, destid, hopcount, port_num)) {
754 				pr_debug(
755 				    "RIO: scanning device on port %d\n",
756 				    port_num);
757 				for (ndestid = 0;
758 				     ndestid < RIO_ANY_DESTID(port->sys_size);
759 				     ndestid++) {
760 					rio_route_get_entry(port, rdev->rswitch,
761 							    RIO_GLOBAL_TABLE,
762 							    ndestid,
763 							    &route_port);
764 					if (route_port == port_num)
765 						break;
766 				}
767 
768 				if (rio_disc_peer
769 				    (net, port, ndestid, hopcount + 1) < 0)
770 					return -1;
771 			}
772 		}
773 	} else
774 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
775 		    rio_name(rdev), rdev->vid, rdev->did);
776 
777 	return 0;
778 }
779 
780 /**
781  * rio_mport_is_active- Tests if master port link is active
782  * @port: Master port to test
783  *
784  * Reads the port error status CSR for the master port to
785  * determine if the port has an active link.  Returns
786  * %PORT_N_ERR_STS_PORT_OK if the  master port is active
787  * or %0 if it is inactive.
788  */
789 static int rio_mport_is_active(struct rio_mport *port)
790 {
791 	u32 result = 0;
792 	u32 ext_ftr_ptr;
793 	int *entry = rio_mport_phys_table;
794 
795 	do {
796 		if ((ext_ftr_ptr =
797 		     rio_mport_get_feature(port, 1, 0, 0, *entry)))
798 			break;
799 	} while (*++entry >= 0);
800 
801 	if (ext_ftr_ptr)
802 		rio_local_read_config_32(port,
803 					 ext_ftr_ptr +
804 					 RIO_PORT_N_ERR_STS_CSR(port->index),
805 					 &result);
806 
807 	return (result & PORT_N_ERR_STS_PORT_OK);
808 }
809 
810 /**
811  * rio_alloc_net- Allocate and configure a new RIO network
812  * @port: Master port associated with the RIO network
813  *
814  * Allocates a RIO network structure, initializes per-network
815  * list heads, and adds the associated master port to the
816  * network list of associated master ports. Returns a
817  * RIO network pointer on success or %NULL on failure.
818  */
819 static struct rio_net __devinit *rio_alloc_net(struct rio_mport *port)
820 {
821 	struct rio_net *net;
822 
823 	net = kzalloc(sizeof(struct rio_net), GFP_KERNEL);
824 	if (net) {
825 		INIT_LIST_HEAD(&net->node);
826 		INIT_LIST_HEAD(&net->devices);
827 		INIT_LIST_HEAD(&net->mports);
828 		list_add_tail(&port->nnode, &net->mports);
829 		net->hport = port;
830 		net->id = next_net++;
831 	}
832 	return net;
833 }
834 
835 /**
836  * rio_update_route_tables- Updates route tables in switches
837  * @port: Master port associated with the RIO network
838  *
839  * For each enumerated device, ensure that each switch in a system
840  * has correct routing entries. Add routes for devices that where
841  * unknown dirung the first enumeration pass through the switch.
842  */
843 static void rio_update_route_tables(struct rio_mport *port)
844 {
845 	struct rio_dev *rdev;
846 	struct rio_switch *rswitch;
847 	u8 sport;
848 	u16 destid;
849 
850 	list_for_each_entry(rdev, &rio_devices, global_list) {
851 
852 		destid = (rio_is_switch(rdev))?rdev->rswitch->destid:rdev->destid;
853 
854 		list_for_each_entry(rswitch, &rio_switches, node) {
855 
856 			if (rio_is_switch(rdev)	&& (rdev->rswitch == rswitch))
857 				continue;
858 
859 			if (RIO_INVALID_ROUTE == rswitch->route_table[destid]) {
860 
861 				sport = rio_get_swpinfo_inport(port,
862 						rswitch->destid, rswitch->hopcount);
863 
864 				if (rswitch->add_entry)	{
865 					rio_route_add_entry(port, rswitch, RIO_GLOBAL_TABLE, destid, sport);
866 					rswitch->route_table[destid] = sport;
867 				}
868 			}
869 		}
870 	}
871 }
872 
873 /**
874  * rio_enum_mport- Start enumeration through a master port
875  * @mport: Master port to send transactions
876  *
877  * Starts the enumeration process. If somebody has enumerated our
878  * master port device, then give up. If not and we have an active
879  * link, then start recursive peer enumeration. Returns %0 if
880  * enumeration succeeds or %-EBUSY if enumeration fails.
881  */
882 int rio_enum_mport(struct rio_mport *mport)
883 {
884 	struct rio_net *net = NULL;
885 	int rc = 0;
886 
887 	printk(KERN_INFO "RIO: enumerate master port %d, %s\n", mport->id,
888 	       mport->name);
889 	/* If somebody else enumerated our master port device, bail. */
890 	if (rio_enum_host(mport) < 0) {
891 		printk(KERN_INFO
892 		       "RIO: master port %d device has been enumerated by a remote host\n",
893 		       mport->id);
894 		rc = -EBUSY;
895 		goto out;
896 	}
897 
898 	/* If master port has an active link, allocate net and enum peers */
899 	if (rio_mport_is_active(mport)) {
900 		if (!(net = rio_alloc_net(mport))) {
901 			printk(KERN_ERR "RIO: failed to allocate new net\n");
902 			rc = -ENOMEM;
903 			goto out;
904 		}
905 		if (rio_enum_peer(net, mport, 0) < 0) {
906 			/* A higher priority host won enumeration, bail. */
907 			printk(KERN_INFO
908 			       "RIO: master port %d device has lost enumeration to a remote host\n",
909 			       mport->id);
910 			rio_clear_locks(mport);
911 			rc = -EBUSY;
912 			goto out;
913 		}
914 		rio_update_route_tables(mport);
915 		rio_clear_locks(mport);
916 	} else {
917 		printk(KERN_INFO "RIO: master port %d link inactive\n",
918 		       mport->id);
919 		rc = -EINVAL;
920 	}
921 
922       out:
923 	return rc;
924 }
925 
926 /**
927  * rio_build_route_tables- Generate route tables from switch route entries
928  *
929  * For each switch device, generate a route table by copying existing
930  * route entries from the switch.
931  */
932 static void rio_build_route_tables(void)
933 {
934 	struct rio_dev *rdev;
935 	int i;
936 	u8 sport;
937 
938 	list_for_each_entry(rdev, &rio_devices, global_list)
939 	    if (rio_is_switch(rdev))
940 		for (i = 0;
941 		     i < RIO_MAX_ROUTE_ENTRIES(rdev->net->hport->sys_size);
942 		     i++) {
943 			if (rio_route_get_entry
944 			    (rdev->net->hport, rdev->rswitch, RIO_GLOBAL_TABLE,
945 			     i, &sport) < 0)
946 				continue;
947 			rdev->rswitch->route_table[i] = sport;
948 		}
949 }
950 
951 /**
952  * rio_enum_timeout- Signal that enumeration timed out
953  * @data: Address of timeout flag.
954  *
955  * When the enumeration complete timer expires, set a flag that
956  * signals to the discovery process that enumeration did not
957  * complete in a sane amount of time.
958  */
959 static void rio_enum_timeout(unsigned long data)
960 {
961 	/* Enumeration timed out, set flag */
962 	*(int *)data = 1;
963 }
964 
965 /**
966  * rio_disc_mport- Start discovery through a master port
967  * @mport: Master port to send transactions
968  *
969  * Starts the discovery process. If we have an active link,
970  * then wait for the signal that enumeration is complete.
971  * When enumeration completion is signaled, start recursive
972  * peer discovery. Returns %0 if discovery succeeds or %-EBUSY
973  * on failure.
974  */
975 int rio_disc_mport(struct rio_mport *mport)
976 {
977 	struct rio_net *net = NULL;
978 	int enum_timeout_flag = 0;
979 
980 	printk(KERN_INFO "RIO: discover master port %d, %s\n", mport->id,
981 	       mport->name);
982 
983 	/* If master port has an active link, allocate net and discover peers */
984 	if (rio_mport_is_active(mport)) {
985 		if (!(net = rio_alloc_net(mport))) {
986 			printk(KERN_ERR "RIO: Failed to allocate new net\n");
987 			goto bail;
988 		}
989 
990 		pr_debug("RIO: wait for enumeration complete...");
991 
992 		rio_enum_timer.expires =
993 		    jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
994 		rio_enum_timer.data = (unsigned long)&enum_timeout_flag;
995 		add_timer(&rio_enum_timer);
996 		while (!rio_enum_complete(mport)) {
997 			mdelay(1);
998 			if (enum_timeout_flag) {
999 				del_timer_sync(&rio_enum_timer);
1000 				goto timeout;
1001 			}
1002 		}
1003 		del_timer_sync(&rio_enum_timer);
1004 
1005 		pr_debug("done\n");
1006 		if (rio_disc_peer(net, mport, RIO_ANY_DESTID(mport->sys_size),
1007 					0) < 0) {
1008 			printk(KERN_INFO
1009 			       "RIO: master port %d device has failed discovery\n",
1010 			       mport->id);
1011 			goto bail;
1012 		}
1013 
1014 		rio_build_route_tables();
1015 	}
1016 
1017 	return 0;
1018 
1019       timeout:
1020 	pr_debug("timeout\n");
1021       bail:
1022 	return -EBUSY;
1023 }
1024