xref: /openbmc/linux/drivers/rapidio/rio-scan.c (revision 64c70b1c)
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(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(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(did));
104 }
105 
106 /**
107  * rio_clear_locks- Release all host locks and signal enumeration complete
108  * @port: Master port to issue transaction
109  *
110  * Marks the component tag CSR on each device with the enumeration
111  * complete flag. When complete, it then release the host locks on
112  * each device. Returns 0 on success or %-EINVAL on failure.
113  */
114 static int rio_clear_locks(struct rio_mport *port)
115 {
116 	struct rio_dev *rdev;
117 	u32 result;
118 	int ret = 0;
119 
120 	/* Write component tag CSR magic complete value */
121 	rio_local_write_config_32(port, RIO_COMPONENT_TAG_CSR,
122 				  RIO_ENUM_CMPL_MAGIC);
123 	list_for_each_entry(rdev, &rio_devices, global_list)
124 	    rio_write_config_32(rdev, RIO_COMPONENT_TAG_CSR,
125 				RIO_ENUM_CMPL_MAGIC);
126 
127 	/* Release host device id locks */
128 	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
129 				  port->host_deviceid);
130 	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
131 	if ((result & 0xffff) != 0xffff) {
132 		printk(KERN_INFO
133 		       "RIO: badness when releasing host lock on master port, result %8.8x\n",
134 		       result);
135 		ret = -EINVAL;
136 	}
137 	list_for_each_entry(rdev, &rio_devices, global_list) {
138 		rio_write_config_32(rdev, RIO_HOST_DID_LOCK_CSR,
139 				    port->host_deviceid);
140 		rio_read_config_32(rdev, RIO_HOST_DID_LOCK_CSR, &result);
141 		if ((result & 0xffff) != 0xffff) {
142 			printk(KERN_INFO
143 			       "RIO: badness when releasing host lock on vid %4.4x did %4.4x\n",
144 			       rdev->vid, rdev->did);
145 			ret = -EINVAL;
146 		}
147 	}
148 
149 	return ret;
150 }
151 
152 /**
153  * rio_enum_host- Set host lock and initialize host destination ID
154  * @port: Master port to issue transaction
155  *
156  * Sets the local host master port lock and destination ID register
157  * with the host device ID value. The host device ID value is provided
158  * by the platform. Returns %0 on success or %-1 on failure.
159  */
160 static int rio_enum_host(struct rio_mport *port)
161 {
162 	u32 result;
163 
164 	/* Set master port host device id lock */
165 	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
166 				  port->host_deviceid);
167 
168 	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
169 	if ((result & 0xffff) != port->host_deviceid)
170 		return -1;
171 
172 	/* Set master port destid and init destid ctr */
173 	rio_local_set_device_id(port, port->host_deviceid);
174 
175 	if (next_destid == port->host_deviceid)
176 		next_destid++;
177 
178 	return 0;
179 }
180 
181 /**
182  * rio_device_has_destid- Test if a device contains a destination ID register
183  * @port: Master port to issue transaction
184  * @src_ops: RIO device source operations
185  * @dst_ops: RIO device destination operations
186  *
187  * Checks the provided @src_ops and @dst_ops for the necessary transaction
188  * capabilities that indicate whether or not a device will implement a
189  * destination ID register. Returns 1 if true or 0 if false.
190  */
191 static int rio_device_has_destid(struct rio_mport *port, int src_ops,
192 				 int dst_ops)
193 {
194 	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;
195 
196 	return !!((src_ops | dst_ops) & mask);
197 }
198 
199 /**
200  * rio_release_dev- Frees a RIO device struct
201  * @dev: LDM device associated with a RIO device struct
202  *
203  * Gets the RIO device struct associated a RIO device struct.
204  * The RIO device struct is freed.
205  */
206 static void rio_release_dev(struct device *dev)
207 {
208 	struct rio_dev *rdev;
209 
210 	rdev = to_rio_dev(dev);
211 	kfree(rdev);
212 }
213 
214 /**
215  * rio_is_switch- Tests if a RIO device has switch capabilities
216  * @rdev: RIO device
217  *
218  * Gets the RIO device Processing Element Features register
219  * contents and tests for switch capabilities. Returns 1 if
220  * the device is a switch or 0 if it is not a switch.
221  * The RIO device struct is freed.
222  */
223 static int rio_is_switch(struct rio_dev *rdev)
224 {
225 	if (rdev->pef & RIO_PEF_SWITCH)
226 		return 1;
227 	return 0;
228 }
229 
230 /**
231  * rio_route_set_ops- Sets routing operations for a particular vendor switch
232  * @rdev: RIO device
233  *
234  * Searches the RIO route ops table for known switch types. If the vid
235  * and did match a switch table entry, then set the add_entry() and
236  * get_entry() ops to the table entry values.
237  */
238 static void rio_route_set_ops(struct rio_dev *rdev)
239 {
240 	struct rio_route_ops *cur = __start_rio_route_ops;
241 	struct rio_route_ops *end = __end_rio_route_ops;
242 
243 	while (cur < end) {
244 		if ((cur->vid == rdev->vid) && (cur->did == rdev->did)) {
245 			pr_debug("RIO: adding routing ops for %s\n", rio_name(rdev));
246 			rdev->rswitch->add_entry = cur->add_hook;
247 			rdev->rswitch->get_entry = cur->get_hook;
248 		}
249 		cur++;
250 	}
251 
252 	if (!rdev->rswitch->add_entry || !rdev->rswitch->get_entry)
253 		printk(KERN_ERR "RIO: missing routing ops for %s\n",
254 		       rio_name(rdev));
255 }
256 
257 /**
258  * rio_add_device- Adds a RIO device to the device model
259  * @rdev: RIO device
260  *
261  * Adds the RIO device to the global device list and adds the RIO
262  * device to the RIO device list.  Creates the generic sysfs nodes
263  * for an RIO device.
264  */
265 static void __devinit rio_add_device(struct rio_dev *rdev)
266 {
267 	device_add(&rdev->dev);
268 
269 	spin_lock(&rio_global_list_lock);
270 	list_add_tail(&rdev->global_list, &rio_devices);
271 	spin_unlock(&rio_global_list_lock);
272 
273 	rio_create_sysfs_dev_files(rdev);
274 }
275 
276 /**
277  * rio_setup_device- Allocates and sets up a RIO device
278  * @net: RIO network
279  * @port: Master port to send transactions
280  * @destid: Current destination ID
281  * @hopcount: Current hopcount
282  * @do_enum: Enumeration/Discovery mode flag
283  *
284  * Allocates a RIO device and configures fields based on configuration
285  * space contents. If device has a destination ID register, a destination
286  * ID is either assigned in enumeration mode or read from configuration
287  * space in discovery mode.  If the device has switch capabilities, then
288  * a switch is allocated and configured appropriately. Returns a pointer
289  * to a RIO device on success or NULL on failure.
290  *
291  */
292 static struct rio_dev *rio_setup_device(struct rio_net *net,
293 					struct rio_mport *port, u16 destid,
294 					u8 hopcount, int do_enum)
295 {
296 	struct rio_dev *rdev;
297 	struct rio_switch *rswitch;
298 	int result, rdid;
299 
300 	rdev = kmalloc(sizeof(struct rio_dev), GFP_KERNEL);
301 	if (!rdev)
302 		goto out;
303 
304 	memset(rdev, 0, sizeof(struct rio_dev));
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 		/* Initialize switch route table */
355 		for (rdid = 0; rdid < RIO_MAX_ROUTE_ENTRIES; rdid++)
356 			rswitch->route_table[rdid] = RIO_INVALID_ROUTE;
357 		rdev->rswitch = rswitch;
358 		sprintf(rio_name(rdev), "%02x:s:%04x", rdev->net->id,
359 			rdev->rswitch->switchid);
360 		rio_route_set_ops(rdev);
361 
362 		list_add_tail(&rswitch->node, &rio_switches);
363 
364 	} else
365 		sprintf(rio_name(rdev), "%02x:e:%04x", rdev->net->id,
366 			rdev->destid);
367 
368 	rdev->dev.bus = &rio_bus_type;
369 
370 	device_initialize(&rdev->dev);
371 	rdev->dev.release = rio_release_dev;
372 	rio_dev_get(rdev);
373 
374 	rdev->dma_mask = DMA_32BIT_MASK;
375 	rdev->dev.dma_mask = &rdev->dma_mask;
376 	rdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
377 
378 	if ((rdev->pef & RIO_PEF_INB_DOORBELL) &&
379 	    (rdev->dst_ops & RIO_DST_OPS_DOORBELL))
380 		rio_init_dbell_res(&rdev->riores[RIO_DOORBELL_RESOURCE],
381 				   0, 0xffff);
382 
383 	rio_add_device(rdev);
384 
385       out:
386 	return rdev;
387 }
388 
389 /**
390  * rio_sport_is_active- Tests if a switch port has an active connection.
391  * @port: Master port to send transaction
392  * @destid: Associated destination ID for switch
393  * @hopcount: Hopcount to reach switch
394  * @sport: Switch port number
395  *
396  * Reads the port error status CSR for a particular switch port to
397  * determine if the port has an active link.  Returns
398  * %PORT_N_ERR_STS_PORT_OK if the port is active or %0 if it is
399  * inactive.
400  */
401 static int
402 rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport)
403 {
404 	u32 result;
405 	u32 ext_ftr_ptr;
406 
407 	int *entry = rio_sport_phys_table;
408 
409 	do {
410 		if ((ext_ftr_ptr =
411 		     rio_mport_get_feature(port, 0, destid, hopcount, *entry)))
412 
413 			break;
414 	} while (*++entry >= 0);
415 
416 	if (ext_ftr_ptr)
417 		rio_mport_read_config_32(port, destid, hopcount,
418 					 ext_ftr_ptr +
419 					 RIO_PORT_N_ERR_STS_CSR(sport),
420 					 &result);
421 
422 	return (result & PORT_N_ERR_STS_PORT_OK);
423 }
424 
425 /**
426  * rio_route_add_entry- Add a route entry to a switch routing table
427  * @mport: Master port to send transaction
428  * @rswitch: Switch device
429  * @table: Routing table ID
430  * @route_destid: Destination ID to be routed
431  * @route_port: Port number to be routed
432  *
433  * Calls the switch specific add_entry() method to add a route entry
434  * on a switch. The route table can be specified using the @table
435  * argument if a switch has per port routing tables or the normal
436  * use is to specific all tables (or the global table) by passing
437  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
438  * on failure.
439  */
440 static int rio_route_add_entry(struct rio_mport *mport, struct rio_switch *rswitch,
441 			       u16 table, u16 route_destid, u8 route_port)
442 {
443 	return rswitch->add_entry(mport, rswitch->destid,
444 					rswitch->hopcount, table,
445 					route_destid, route_port);
446 }
447 
448 /**
449  * rio_route_get_entry- Read a route entry in a switch routing table
450  * @mport: Master port to send transaction
451  * @rswitch: Switch device
452  * @table: Routing table ID
453  * @route_destid: Destination ID to be routed
454  * @route_port: Pointer to read port number into
455  *
456  * Calls the switch specific get_entry() method to read a route entry
457  * in a switch. The route table can be specified using the @table
458  * argument if a switch has per port routing tables or the normal
459  * use is to specific all tables (or the global table) by passing
460  * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL
461  * on failure.
462  */
463 static int
464 rio_route_get_entry(struct rio_mport *mport, struct rio_switch *rswitch, u16 table,
465 		    u16 route_destid, u8 * route_port)
466 {
467 	return rswitch->get_entry(mport, rswitch->destid,
468 					rswitch->hopcount, table,
469 					route_destid, route_port);
470 }
471 
472 /**
473  * rio_get_host_deviceid_lock- Reads the Host Device ID Lock CSR on a device
474  * @port: Master port to send transaction
475  * @hopcount: Number of hops to the device
476  *
477  * Used during enumeration to read the Host Device ID Lock CSR on a
478  * RIO device. Returns the value of the lock register.
479  */
480 static u16 rio_get_host_deviceid_lock(struct rio_mport *port, u8 hopcount)
481 {
482 	u32 result;
483 
484 	rio_mport_read_config_32(port, RIO_ANY_DESTID, hopcount,
485 				 RIO_HOST_DID_LOCK_CSR, &result);
486 
487 	return (u16) (result & 0xffff);
488 }
489 
490 /**
491  * rio_get_swpinfo_inport- Gets the ingress port number
492  * @mport: Master port to send transaction
493  * @destid: Destination ID associated with the switch
494  * @hopcount: Number of hops to the device
495  *
496  * Returns port number being used to access the switch device.
497  */
498 static u8
499 rio_get_swpinfo_inport(struct rio_mport *mport, u16 destid, u8 hopcount)
500 {
501 	u32 result;
502 
503 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
504 				 &result);
505 
506 	return (u8) (result & 0xff);
507 }
508 
509 /**
510  * rio_get_swpinfo_tports- Gets total number of ports on the switch
511  * @mport: Master port to send transaction
512  * @destid: Destination ID associated with the switch
513  * @hopcount: Number of hops to the device
514  *
515  * Returns total numbers of ports implemented by the switch device.
516  */
517 static u8 rio_get_swpinfo_tports(struct rio_mport *mport, u16 destid,
518 				 u8 hopcount)
519 {
520 	u32 result;
521 
522 	rio_mport_read_config_32(mport, destid, hopcount, RIO_SWP_INFO_CAR,
523 				 &result);
524 
525 	return RIO_GET_TOTAL_PORTS(result);
526 }
527 
528 /**
529  * rio_net_add_mport- Add a master port to a RIO network
530  * @net: RIO network
531  * @port: Master port to add
532  *
533  * Adds a master port to the network list of associated master
534  * ports..
535  */
536 static void rio_net_add_mport(struct rio_net *net, struct rio_mport *port)
537 {
538 	spin_lock(&rio_global_list_lock);
539 	list_add_tail(&port->nnode, &net->mports);
540 	spin_unlock(&rio_global_list_lock);
541 }
542 
543 /**
544  * rio_enum_peer- Recursively enumerate a RIO network through a master port
545  * @net: RIO network being enumerated
546  * @port: Master port to send transactions
547  * @hopcount: Number of hops into the network
548  *
549  * Recursively enumerates a RIO network.  Transactions are sent via the
550  * master port passed in @port.
551  */
552 static int rio_enum_peer(struct rio_net *net, struct rio_mport *port,
553 			 u8 hopcount)
554 {
555 	int port_num;
556 	int num_ports;
557 	int cur_destid;
558 	int sw_destid;
559 	int sw_inport;
560 	struct rio_dev *rdev;
561 	u16 destid;
562 	int tmp;
563 
564 	if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
565 		pr_debug("RIO: PE already discovered by this host\n");
566 		/*
567 		 * Already discovered by this host. Add it as another
568 		 * master port for the current network.
569 		 */
570 		rio_net_add_mport(net, port);
571 		return 0;
572 	}
573 
574 	/* Attempt to acquire device lock */
575 	rio_mport_write_config_32(port, RIO_ANY_DESTID, hopcount,
576 				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
577 	while ((tmp = rio_get_host_deviceid_lock(port, hopcount))
578 	       < port->host_deviceid) {
579 		/* Delay a bit */
580 		mdelay(1);
581 		/* Attempt to acquire device lock again */
582 		rio_mport_write_config_32(port, RIO_ANY_DESTID, hopcount,
583 					  RIO_HOST_DID_LOCK_CSR,
584 					  port->host_deviceid);
585 	}
586 
587 	if (rio_get_host_deviceid_lock(port, hopcount) > port->host_deviceid) {
588 		pr_debug(
589 		    "RIO: PE locked by a higher priority host...retreating\n");
590 		return -1;
591 	}
592 
593 	/* Setup new RIO device */
594 	if ((rdev = rio_setup_device(net, port, RIO_ANY_DESTID, hopcount, 1))) {
595 		/* Add device to the global and bus/net specific list. */
596 		list_add_tail(&rdev->net_list, &net->devices);
597 	} else
598 		return -1;
599 
600 	if (rio_is_switch(rdev)) {
601 		next_switchid++;
602 		sw_inport = rio_get_swpinfo_inport(port, RIO_ANY_DESTID, hopcount);
603 		rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,
604 				    port->host_deviceid, sw_inport);
605 		rdev->rswitch->route_table[port->host_deviceid] = sw_inport;
606 
607 		for (destid = 0; destid < next_destid; destid++) {
608 			if (destid == port->host_deviceid)
609 				continue;
610 			rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,
611 					    destid, sw_inport);
612 			rdev->rswitch->route_table[destid] = sw_inport;
613 		}
614 
615 		num_ports =
616 		    rio_get_swpinfo_tports(port, RIO_ANY_DESTID, hopcount);
617 		pr_debug(
618 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
619 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
620 		sw_destid = next_destid;
621 		for (port_num = 0; port_num < num_ports; port_num++) {
622 			if (sw_inport == port_num)
623 				continue;
624 
625 			cur_destid = next_destid;
626 
627 			if (rio_sport_is_active
628 			    (port, RIO_ANY_DESTID, hopcount, port_num)) {
629 				pr_debug(
630 				    "RIO: scanning device on port %d\n",
631 				    port_num);
632 				rio_route_add_entry(port, rdev->rswitch,
633 						    RIO_GLOBAL_TABLE,
634 						    RIO_ANY_DESTID, port_num);
635 
636 				if (rio_enum_peer(net, port, hopcount + 1) < 0)
637 					return -1;
638 
639 				/* Update routing tables */
640 				if (next_destid > cur_destid) {
641 					for (destid = cur_destid;
642 					     destid < next_destid; destid++) {
643 						if (destid == port->host_deviceid)
644 							continue;
645 						rio_route_add_entry(port, rdev->rswitch,
646 								    RIO_GLOBAL_TABLE,
647 								    destid,
648 								    port_num);
649 						rdev->rswitch->
650 						    route_table[destid] =
651 						    port_num;
652 					}
653 				}
654 			}
655 		}
656 
657 		/* Check for empty switch */
658 		if (next_destid == sw_destid) {
659 			next_destid++;
660 			if (next_destid == port->host_deviceid)
661 				next_destid++;
662 		}
663 
664 		rdev->rswitch->destid = sw_destid;
665 	} else
666 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
667 		    rio_name(rdev), rdev->vid, rdev->did);
668 
669 	return 0;
670 }
671 
672 /**
673  * rio_enum_complete- Tests if enumeration of a network is complete
674  * @port: Master port to send transaction
675  *
676  * Tests the Component Tag CSR for presence of the magic enumeration
677  * complete flag. Return %1 if enumeration is complete or %0 if
678  * enumeration is incomplete.
679  */
680 static int rio_enum_complete(struct rio_mport *port)
681 {
682 	u32 tag_csr;
683 	int ret = 0;
684 
685 	rio_local_read_config_32(port, RIO_COMPONENT_TAG_CSR, &tag_csr);
686 
687 	if (tag_csr == RIO_ENUM_CMPL_MAGIC)
688 		ret = 1;
689 
690 	return ret;
691 }
692 
693 /**
694  * rio_disc_peer- Recursively discovers a RIO network through a master port
695  * @net: RIO network being discovered
696  * @port: Master port to send transactions
697  * @destid: Current destination ID in network
698  * @hopcount: Number of hops into the network
699  *
700  * Recursively discovers a RIO network.  Transactions are sent via the
701  * master port passed in @port.
702  */
703 static int
704 rio_disc_peer(struct rio_net *net, struct rio_mport *port, u16 destid,
705 	      u8 hopcount)
706 {
707 	u8 port_num, route_port;
708 	int num_ports;
709 	struct rio_dev *rdev;
710 	u16 ndestid;
711 
712 	/* Setup new RIO device */
713 	if ((rdev = rio_setup_device(net, port, destid, hopcount, 0))) {
714 		/* Add device to the global and bus/net specific list. */
715 		list_add_tail(&rdev->net_list, &net->devices);
716 	} else
717 		return -1;
718 
719 	if (rio_is_switch(rdev)) {
720 		next_switchid++;
721 
722 		/* Associated destid is how we accessed this switch */
723 		rdev->rswitch->destid = destid;
724 
725 		num_ports = rio_get_swpinfo_tports(port, destid, hopcount);
726 		pr_debug(
727 		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
728 		    rio_name(rdev), rdev->vid, rdev->did, num_ports);
729 		for (port_num = 0; port_num < num_ports; port_num++) {
730 			if (rio_get_swpinfo_inport(port, destid, hopcount) ==
731 			    port_num)
732 				continue;
733 
734 			if (rio_sport_is_active
735 			    (port, destid, hopcount, port_num)) {
736 				pr_debug(
737 				    "RIO: scanning device on port %d\n",
738 				    port_num);
739 				for (ndestid = 0; ndestid < RIO_ANY_DESTID;
740 				     ndestid++) {
741 					rio_route_get_entry(port, rdev->rswitch,
742 							    RIO_GLOBAL_TABLE,
743 							    ndestid,
744 							    &route_port);
745 					if (route_port == port_num)
746 						break;
747 				}
748 
749 				if (rio_disc_peer
750 				    (net, port, ndestid, hopcount + 1) < 0)
751 					return -1;
752 			}
753 		}
754 	} else
755 		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
756 		    rio_name(rdev), rdev->vid, rdev->did);
757 
758 	return 0;
759 }
760 
761 /**
762  * rio_mport_is_active- Tests if master port link is active
763  * @port: Master port to test
764  *
765  * Reads the port error status CSR for the master port to
766  * determine if the port has an active link.  Returns
767  * %PORT_N_ERR_STS_PORT_OK if the  master port is active
768  * or %0 if it is inactive.
769  */
770 static int rio_mport_is_active(struct rio_mport *port)
771 {
772 	u32 result = 0;
773 	u32 ext_ftr_ptr;
774 	int *entry = rio_mport_phys_table;
775 
776 	do {
777 		if ((ext_ftr_ptr =
778 		     rio_mport_get_feature(port, 1, 0, 0, *entry)))
779 			break;
780 	} while (*++entry >= 0);
781 
782 	if (ext_ftr_ptr)
783 		rio_local_read_config_32(port,
784 					 ext_ftr_ptr +
785 					 RIO_PORT_N_ERR_STS_CSR(port->index),
786 					 &result);
787 
788 	return (result & PORT_N_ERR_STS_PORT_OK);
789 }
790 
791 /**
792  * rio_alloc_net- Allocate and configure a new RIO network
793  * @port: Master port associated with the RIO network
794  *
795  * Allocates a RIO network structure, initializes per-network
796  * list heads, and adds the associated master port to the
797  * network list of associated master ports. Returns a
798  * RIO network pointer on success or %NULL on failure.
799  */
800 static struct rio_net __devinit *rio_alloc_net(struct rio_mport *port)
801 {
802 	struct rio_net *net;
803 
804 	net = kmalloc(sizeof(struct rio_net), GFP_KERNEL);
805 	if (net) {
806 		memset(net, 0, sizeof(struct rio_net));
807 		INIT_LIST_HEAD(&net->node);
808 		INIT_LIST_HEAD(&net->devices);
809 		INIT_LIST_HEAD(&net->mports);
810 		list_add_tail(&port->nnode, &net->mports);
811 		net->hport = port;
812 		net->id = next_net++;
813 	}
814 	return net;
815 }
816 
817 /**
818  * rio_update_route_tables- Updates route tables in switches
819  * @port: Master port associated with the RIO network
820  *
821  * For each enumerated device, ensure that each switch in a system
822  * has correct routing entries. Add routes for devices that where
823  * unknown dirung the first enumeration pass through the switch.
824  */
825 static void rio_update_route_tables(struct rio_mport *port)
826 {
827 	struct rio_dev *rdev;
828 	struct rio_switch *rswitch;
829 	u8 sport;
830 	u16 destid;
831 
832 	list_for_each_entry(rdev, &rio_devices, global_list) {
833 
834 		destid = (rio_is_switch(rdev))?rdev->rswitch->destid:rdev->destid;
835 
836 		list_for_each_entry(rswitch, &rio_switches, node) {
837 
838 			if (rio_is_switch(rdev)	&& (rdev->rswitch == rswitch))
839 				continue;
840 
841 			if (RIO_INVALID_ROUTE == rswitch->route_table[destid]) {
842 
843 				sport = rio_get_swpinfo_inport(port,
844 						rswitch->destid, rswitch->hopcount);
845 
846 				if (rswitch->add_entry)	{
847 					rio_route_add_entry(port, rswitch, RIO_GLOBAL_TABLE, destid, sport);
848 					rswitch->route_table[destid] = sport;
849 				}
850 			}
851 		}
852 	}
853 }
854 
855 /**
856  * rio_enum_mport- Start enumeration through a master port
857  * @mport: Master port to send transactions
858  *
859  * Starts the enumeration process. If somebody has enumerated our
860  * master port device, then give up. If not and we have an active
861  * link, then start recursive peer enumeration. Returns %0 if
862  * enumeration succeeds or %-EBUSY if enumeration fails.
863  */
864 int rio_enum_mport(struct rio_mport *mport)
865 {
866 	struct rio_net *net = NULL;
867 	int rc = 0;
868 
869 	printk(KERN_INFO "RIO: enumerate master port %d, %s\n", mport->id,
870 	       mport->name);
871 	/* If somebody else enumerated our master port device, bail. */
872 	if (rio_enum_host(mport) < 0) {
873 		printk(KERN_INFO
874 		       "RIO: master port %d device has been enumerated by a remote host\n",
875 		       mport->id);
876 		rc = -EBUSY;
877 		goto out;
878 	}
879 
880 	/* If master port has an active link, allocate net and enum peers */
881 	if (rio_mport_is_active(mport)) {
882 		if (!(net = rio_alloc_net(mport))) {
883 			printk(KERN_ERR "RIO: failed to allocate new net\n");
884 			rc = -ENOMEM;
885 			goto out;
886 		}
887 		if (rio_enum_peer(net, mport, 0) < 0) {
888 			/* A higher priority host won enumeration, bail. */
889 			printk(KERN_INFO
890 			       "RIO: master port %d device has lost enumeration to a remote host\n",
891 			       mport->id);
892 			rio_clear_locks(mport);
893 			rc = -EBUSY;
894 			goto out;
895 		}
896 		rio_update_route_tables(mport);
897 		rio_clear_locks(mport);
898 	} else {
899 		printk(KERN_INFO "RIO: master port %d link inactive\n",
900 		       mport->id);
901 		rc = -EINVAL;
902 	}
903 
904       out:
905 	return rc;
906 }
907 
908 /**
909  * rio_build_route_tables- Generate route tables from switch route entries
910  *
911  * For each switch device, generate a route table by copying existing
912  * route entries from the switch.
913  */
914 static void rio_build_route_tables(void)
915 {
916 	struct rio_dev *rdev;
917 	int i;
918 	u8 sport;
919 
920 	list_for_each_entry(rdev, &rio_devices, global_list)
921 	    if (rio_is_switch(rdev))
922 		for (i = 0; i < RIO_MAX_ROUTE_ENTRIES; i++) {
923 			if (rio_route_get_entry
924 			    (rdev->net->hport, rdev->rswitch, RIO_GLOBAL_TABLE,
925 			     i, &sport) < 0)
926 				continue;
927 			rdev->rswitch->route_table[i] = sport;
928 		}
929 }
930 
931 /**
932  * rio_enum_timeout- Signal that enumeration timed out
933  * @data: Address of timeout flag.
934  *
935  * When the enumeration complete timer expires, set a flag that
936  * signals to the discovery process that enumeration did not
937  * complete in a sane amount of time.
938  */
939 static void rio_enum_timeout(unsigned long data)
940 {
941 	/* Enumeration timed out, set flag */
942 	*(int *)data = 1;
943 }
944 
945 /**
946  * rio_disc_mport- Start discovery through a master port
947  * @mport: Master port to send transactions
948  *
949  * Starts the discovery process. If we have an active link,
950  * then wait for the signal that enumeration is complete.
951  * When enumeration completion is signaled, start recursive
952  * peer discovery. Returns %0 if discovery succeeds or %-EBUSY
953  * on failure.
954  */
955 int rio_disc_mport(struct rio_mport *mport)
956 {
957 	struct rio_net *net = NULL;
958 	int enum_timeout_flag = 0;
959 
960 	printk(KERN_INFO "RIO: discover master port %d, %s\n", mport->id,
961 	       mport->name);
962 
963 	/* If master port has an active link, allocate net and discover peers */
964 	if (rio_mport_is_active(mport)) {
965 		if (!(net = rio_alloc_net(mport))) {
966 			printk(KERN_ERR "RIO: Failed to allocate new net\n");
967 			goto bail;
968 		}
969 
970 		pr_debug("RIO: wait for enumeration complete...");
971 
972 		rio_enum_timer.expires =
973 		    jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
974 		rio_enum_timer.data = (unsigned long)&enum_timeout_flag;
975 		add_timer(&rio_enum_timer);
976 		while (!rio_enum_complete(mport)) {
977 			mdelay(1);
978 			if (enum_timeout_flag) {
979 				del_timer_sync(&rio_enum_timer);
980 				goto timeout;
981 			}
982 		}
983 		del_timer_sync(&rio_enum_timer);
984 
985 		pr_debug("done\n");
986 		if (rio_disc_peer(net, mport, RIO_ANY_DESTID, 0) < 0) {
987 			printk(KERN_INFO
988 			       "RIO: master port %d device has failed discovery\n",
989 			       mport->id);
990 			goto bail;
991 		}
992 
993 		rio_build_route_tables();
994 	}
995 
996 	return 0;
997 
998       timeout:
999 	pr_debug("timeout\n");
1000       bail:
1001 	return -EBUSY;
1002 }
1003