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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/hvcs.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/char/hvcs.c')
-rw-r--r--drivers/char/hvcs.c1649
1 files changed, 1649 insertions, 0 deletions
diff --git a/drivers/char/hvcs.c b/drivers/char/hvcs.c
new file mode 100644
index 000000000000..abfbdcfd4e72
--- /dev/null
+++ b/drivers/char/hvcs.c
@@ -0,0 +1,1649 @@
1/*
2 * IBM eServer Hypervisor Virtual Console Server Device Driver
3 * Copyright (C) 2003, 2004 IBM Corp.
4 * Ryan S. Arnold (rsa@us.ibm.com)
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 * Author(s) : Ryan S. Arnold <rsa@us.ibm.com>
21 *
22 * This is the device driver for the IBM Hypervisor Virtual Console Server,
23 * "hvcs". The IBM hvcs provides a tty driver interface to allow Linux
24 * user space applications access to the system consoles of logically
25 * partitioned operating systems, e.g. Linux, running on the same partitioned
26 * Power5 ppc64 system. Physical hardware consoles per partition are not
27 * practical on this hardware so system consoles are accessed by this driver
28 * using inter-partition firmware interfaces to virtual terminal devices.
29 *
30 * A vty is known to the HMC as a "virtual serial server adapter". It is a
31 * virtual terminal device that is created by firmware upon partition creation
32 * to act as a partitioned OS's console device.
33 *
34 * Firmware dynamically (via hotplug) exposes vty-servers to a running ppc64
35 * Linux system upon their creation by the HMC or their exposure during boot.
36 * The non-user interactive backend of this driver is implemented as a vio
37 * device driver so that it can receive notification of vty-server lifetimes
38 * after it registers with the vio bus to handle vty-server probe and remove
39 * callbacks.
40 *
41 * Many vty-servers can be configured to connect to one vty, but a vty can
42 * only be actively connected to by a single vty-server, in any manner, at one
43 * time. If the HMC is currently hosting the console for a target Linux
44 * partition; attempts to open the tty device to the partition's console using
45 * the hvcs on any partition will return -EBUSY with every open attempt until
46 * the HMC frees the connection between its vty-server and the desired
47 * partition's vty device. Conversely, a vty-server may only be connected to
48 * a single vty at one time even though it may have several configured vty
49 * partner possibilities.
50 *
51 * Firmware does not provide notification of vty partner changes to this
52 * driver. This means that an HMC Super Admin may add or remove partner vtys
53 * from a vty-server's partner list but the changes will not be signaled to
54 * the vty-server. Firmware only notifies the driver when a vty-server is
55 * added or removed from the system. To compensate for this deficiency, this
56 * driver implements a sysfs update attribute which provides a method for
57 * rescanning partner information upon a user's request.
58 *
59 * Each vty-server, prior to being exposed to this driver is reference counted
60 * using the 2.6 Linux kernel kobject construct. This kobject is also used by
61 * the vio bus to provide a vio device sysfs entry that this driver attaches
62 * device specific attributes to, including partner information. The vio bus
63 * framework also provides a sysfs entry for each vio driver. The hvcs driver
64 * provides driver attributes in this entry.
65 *
66 * For direction on installation and usage of this driver please reference
67 * Documentation/powerpc/hvcs.txt.
68 */
69
70#include <linux/device.h>
71#include <linux/init.h>
72#include <linux/interrupt.h>
73#include <linux/kernel.h>
74#include <linux/kobject.h>
75#include <linux/kthread.h>
76#include <linux/list.h>
77#include <linux/major.h>
78#include <linux/module.h>
79#include <linux/moduleparam.h>
80#include <linux/sched.h>
81#include <linux/spinlock.h>
82#include <linux/stat.h>
83#include <linux/tty.h>
84#include <linux/tty_flip.h>
85#include <asm/hvconsole.h>
86#include <asm/hvcserver.h>
87#include <asm/uaccess.h>
88#include <asm/vio.h>
89
90/*
91 * 1.3.0 -> 1.3.1 In hvcs_open memset(..,0x00,..) instead of memset(..,0x3F,00).
92 * Removed braces around single statements following conditionals. Removed '=
93 * 0' after static int declarations since these default to zero. Removed
94 * list_for_each_safe() and replaced with list_for_each_entry() in
95 * hvcs_get_by_index(). The 'safe' version is un-needed now that the driver is
96 * using spinlocks. Changed spin_lock_irqsave() to spin_lock() when locking
97 * hvcs_structs_lock and hvcs_pi_lock since these are not touched in an int
98 * handler. Initialized hvcs_structs_lock and hvcs_pi_lock to
99 * SPIN_LOCK_UNLOCKED at declaration time rather than in hvcs_module_init().
100 * Added spin_lock around list_del() in destroy_hvcs_struct() to protect the
101 * list traversals from a deletion. Removed '= NULL' from pointer declaration
102 * statements since they are initialized NULL by default. Removed wmb()
103 * instances from hvcs_try_write(). They probably aren't needed with locking in
104 * place. Added check and cleanup for hvcs_pi_buff = kmalloc() in
105 * hvcs_module_init(). Exposed hvcs_struct.index via a sysfs attribute so that
106 * the coupling between /dev/hvcs* and a vty-server can be automatically
107 * determined. Moved kobject_put() in hvcs_open outside of the
108 * spin_unlock_irqrestore().
109 *
110 * 1.3.1 -> 1.3.2 Changed method for determining hvcs_struct->index and had it
111 * align with how the tty layer always assigns the lowest index available. This
112 * change resulted in a list of ints that denotes which indexes are available.
113 * Device additions and removals use the new hvcs_get_index() and
114 * hvcs_return_index() helper functions. The list is created with
115 * hvsc_alloc_index_list() and it is destroyed with hvcs_free_index_list().
116 * Without these fixes hotplug vty-server adapter support goes crazy with this
117 * driver if the user removes a vty-server adapter. Moved free_irq() outside of
118 * the hvcs_final_close() function in order to get it out of the spinlock.
119 * Rearranged hvcs_close(). Cleaned up some printks and did some housekeeping
120 * on the changelog. Removed local CLC_LENGTH and used HVCS_CLC_LENGTH from
121 * arch/ppc64/hvcserver.h.
122 *
123 * 1.3.2 -> 1.3.3 Replaced yield() in hvcs_close() with tty_wait_until_sent() to
124 * prevent possible lockup with realtime scheduling as similarily pointed out by
125 * akpm in hvc_console. Changed resulted in the removal of hvcs_final_close()
126 * to reorder cleanup operations and prevent discarding of pending data during
127 * an hvcs_close(). Removed spinlock protection of hvcs_struct data members in
128 * hvcs_write_room() and hvcs_chars_in_buffer() because they aren't needed.
129 */
130
131#define HVCS_DRIVER_VERSION "1.3.3"
132
133MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>");
134MODULE_DESCRIPTION("IBM hvcs (Hypervisor Virtual Console Server) Driver");
135MODULE_LICENSE("GPL");
136MODULE_VERSION(HVCS_DRIVER_VERSION);
137
138/*
139 * Wait this long per iteration while trying to push buffered data to the
140 * hypervisor before allowing the tty to complete a close operation.
141 */
142#define HVCS_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
143
144/*
145 * Since the Linux TTY code does not currently (2-04-2004) support dynamic
146 * addition of tty derived devices and we shouldn't allocate thousands of
147 * tty_device pointers when the number of vty-server & vty partner connections
148 * will most often be much lower than this, we'll arbitrarily allocate
149 * HVCS_DEFAULT_SERVER_ADAPTERS tty_structs and cdev's by default when we
150 * register the tty_driver. This can be overridden using an insmod parameter.
151 */
152#define HVCS_DEFAULT_SERVER_ADAPTERS 64
153
154/*
155 * The user can't insmod with more than HVCS_MAX_SERVER_ADAPTERS hvcs device
156 * nodes as a sanity check. Theoretically there can be over 1 Billion
157 * vty-server & vty partner connections.
158 */
159#define HVCS_MAX_SERVER_ADAPTERS 1024
160
161/*
162 * We let Linux assign us a major number and we start the minors at zero. There
163 * is no intuitive mapping between minor number and the target vty-server
164 * adapter except that each new vty-server adapter is always assigned to the
165 * smallest minor number available.
166 */
167#define HVCS_MINOR_START 0
168
169/*
170 * The hcall interface involves putting 8 chars into each of two registers.
171 * We load up those 2 registers (in arch/ppc64/hvconsole.c) by casting char[16]
172 * to long[2]. It would work without __ALIGNED__, but a little (tiny) bit
173 * slower because an unaligned load is slower than aligned load.
174 */
175#define __ALIGNED__ __attribute__((__aligned__(8)))
176
177/*
178 * How much data can firmware send with each hvc_put_chars()? Maybe this
179 * should be moved into an architecture specific area.
180 */
181#define HVCS_BUFF_LEN 16
182
183/*
184 * This is the maximum amount of data we'll let the user send us (hvcs_write) at
185 * once in a chunk as a sanity check.
186 */
187#define HVCS_MAX_FROM_USER 4096
188
189/*
190 * Be careful when adding flags to this line discipline. Don't add anything
191 * that will cause echoing or we'll go into recursive loop echoing chars back
192 * and forth with the console drivers.
193 */
194static struct termios hvcs_tty_termios = {
195 .c_iflag = IGNBRK | IGNPAR,
196 .c_oflag = OPOST,
197 .c_cflag = B38400 | CS8 | CREAD | HUPCL,
198 .c_cc = INIT_C_CC
199};
200
201/*
202 * This value is used to take the place of a command line parameter when the
203 * module is inserted. It starts as -1 and stays as such if the user doesn't
204 * specify a module insmod parameter. If they DO specify one then it is set to
205 * the value of the integer passed in.
206 */
207static int hvcs_parm_num_devs = -1;
208module_param(hvcs_parm_num_devs, int, 0);
209
210char hvcs_driver_name[] = "hvcs";
211char hvcs_device_node[] = "hvcs";
212char hvcs_driver_string[]
213 = "IBM hvcs (Hypervisor Virtual Console Server) Driver";
214
215/* Status of partner info rescan triggered via sysfs. */
216static int hvcs_rescan_status;
217
218static struct tty_driver *hvcs_tty_driver;
219
220/*
221 * In order to be somewhat sane this driver always associates the hvcs_struct
222 * index element with the numerically equal tty->index. This means that a
223 * hotplugged vty-server adapter will always map to the lowest index valued
224 * device node. If vty-servers were hotplug removed from the system and then
225 * new ones added the new vty-server may have the largest slot number of all
226 * the vty-server adapters in the partition but it may have the lowest dev node
227 * index of all the adapters due to the hole left by the hotplug removed
228 * adapter. There are a set of functions provided to get the lowest index for
229 * a new device as well as return the index to the list. This list is allocated
230 * with a number of elements equal to the number of device nodes requested when
231 * the module was inserted.
232 */
233static int *hvcs_index_list;
234
235/*
236 * How large is the list? This is kept for traversal since the list is
237 * dynamically created.
238 */
239static int hvcs_index_count;
240
241/*
242 * Used by the khvcsd to pick up I/O operations when the kernel_thread is
243 * already awake but potentially shifted to TASK_INTERRUPTIBLE state.
244 */
245static int hvcs_kicked;
246
247/*
248 * Use by the kthread construct for task operations like waking the sleeping
249 * thread and stopping the kthread.
250 */
251static struct task_struct *hvcs_task;
252
253/*
254 * We allocate this for the use of all of the hvcs_structs when they fetch
255 * partner info.
256 */
257static unsigned long *hvcs_pi_buff;
258
259/* Only allow one hvcs_struct to use the hvcs_pi_buff at a time. */
260static DEFINE_SPINLOCK(hvcs_pi_lock);
261
262/* One vty-server per hvcs_struct */
263struct hvcs_struct {
264 spinlock_t lock;
265
266 /*
267 * This index identifies this hvcs device as the complement to a
268 * specific tty index.
269 */
270 unsigned int index;
271
272 struct tty_struct *tty;
273 unsigned int open_count;
274
275 /*
276 * Used to tell the driver kernel_thread what operations need to take
277 * place upon this hvcs_struct instance.
278 */
279 int todo_mask;
280
281 /*
282 * This buffer is required so that when hvcs_write_room() reports that
283 * it can send HVCS_BUFF_LEN characters that it will buffer the full
284 * HVCS_BUFF_LEN characters if need be. This is essential for opost
285 * writes since they do not do high level buffering and expect to be
286 * able to send what the driver commits to sending buffering
287 * [e.g. tab to space conversions in n_tty.c opost()].
288 */
289 char buffer[HVCS_BUFF_LEN];
290 int chars_in_buffer;
291
292 /*
293 * Any variable below the kobject is valid before a tty is connected and
294 * stays valid after the tty is disconnected. These shouldn't be
295 * whacked until the koject refcount reaches zero though some entries
296 * may be changed via sysfs initiatives.
297 */
298 struct kobject kobj; /* ref count & hvcs_struct lifetime */
299 int connected; /* is the vty-server currently connected to a vty? */
300 uint32_t p_unit_address; /* partner unit address */
301 uint32_t p_partition_ID; /* partner partition ID */
302 char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */
303 struct list_head next; /* list management */
304 struct vio_dev *vdev;
305};
306
307/* Required to back map a kobject to its containing object */
308#define from_kobj(kobj) container_of(kobj, struct hvcs_struct, kobj)
309
310static struct list_head hvcs_structs = LIST_HEAD_INIT(hvcs_structs);
311static DEFINE_SPINLOCK(hvcs_structs_lock);
312
313static void hvcs_unthrottle(struct tty_struct *tty);
314static void hvcs_throttle(struct tty_struct *tty);
315static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance,
316 struct pt_regs *regs);
317
318static int hvcs_write(struct tty_struct *tty,
319 const unsigned char *buf, int count);
320static int hvcs_write_room(struct tty_struct *tty);
321static int hvcs_chars_in_buffer(struct tty_struct *tty);
322
323static int hvcs_has_pi(struct hvcs_struct *hvcsd);
324static void hvcs_set_pi(struct hvcs_partner_info *pi,
325 struct hvcs_struct *hvcsd);
326static int hvcs_get_pi(struct hvcs_struct *hvcsd);
327static int hvcs_rescan_devices_list(void);
328
329static int hvcs_partner_connect(struct hvcs_struct *hvcsd);
330static void hvcs_partner_free(struct hvcs_struct *hvcsd);
331
332static int hvcs_enable_device(struct hvcs_struct *hvcsd,
333 uint32_t unit_address, unsigned int irq, struct vio_dev *dev);
334
335static void destroy_hvcs_struct(struct kobject *kobj);
336static int hvcs_open(struct tty_struct *tty, struct file *filp);
337static void hvcs_close(struct tty_struct *tty, struct file *filp);
338static void hvcs_hangup(struct tty_struct * tty);
339
340static void hvcs_create_device_attrs(struct hvcs_struct *hvcsd);
341static void hvcs_remove_device_attrs(struct vio_dev *vdev);
342static void hvcs_create_driver_attrs(void);
343static void hvcs_remove_driver_attrs(void);
344
345static int __devinit hvcs_probe(struct vio_dev *dev,
346 const struct vio_device_id *id);
347static int __devexit hvcs_remove(struct vio_dev *dev);
348static int __init hvcs_module_init(void);
349static void __exit hvcs_module_exit(void);
350
351#define HVCS_SCHED_READ 0x00000001
352#define HVCS_QUICK_READ 0x00000002
353#define HVCS_TRY_WRITE 0x00000004
354#define HVCS_READ_MASK (HVCS_SCHED_READ | HVCS_QUICK_READ)
355
356static void hvcs_kick(void)
357{
358 hvcs_kicked = 1;
359 wmb();
360 wake_up_process(hvcs_task);
361}
362
363static void hvcs_unthrottle(struct tty_struct *tty)
364{
365 struct hvcs_struct *hvcsd = tty->driver_data;
366 unsigned long flags;
367
368 spin_lock_irqsave(&hvcsd->lock, flags);
369 hvcsd->todo_mask |= HVCS_SCHED_READ;
370 spin_unlock_irqrestore(&hvcsd->lock, flags);
371 hvcs_kick();
372}
373
374static void hvcs_throttle(struct tty_struct *tty)
375{
376 struct hvcs_struct *hvcsd = tty->driver_data;
377 unsigned long flags;
378
379 spin_lock_irqsave(&hvcsd->lock, flags);
380 vio_disable_interrupts(hvcsd->vdev);
381 spin_unlock_irqrestore(&hvcsd->lock, flags);
382}
383
384/*
385 * If the device is being removed we don't have to worry about this interrupt
386 * handler taking any further interrupts because they are disabled which means
387 * the hvcs_struct will always be valid in this handler.
388 */
389static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance,
390 struct pt_regs *regs)
391{
392 struct hvcs_struct *hvcsd = dev_instance;
393
394 spin_lock(&hvcsd->lock);
395 vio_disable_interrupts(hvcsd->vdev);
396 hvcsd->todo_mask |= HVCS_SCHED_READ;
397 spin_unlock(&hvcsd->lock);
398 hvcs_kick();
399
400 return IRQ_HANDLED;
401}
402
403/* This function must be called with the hvcsd->lock held */
404static void hvcs_try_write(struct hvcs_struct *hvcsd)
405{
406 uint32_t unit_address = hvcsd->vdev->unit_address;
407 struct tty_struct *tty = hvcsd->tty;
408 int sent;
409
410 if (hvcsd->todo_mask & HVCS_TRY_WRITE) {
411 /* won't send partial writes */
412 sent = hvc_put_chars(unit_address,
413 &hvcsd->buffer[0],
414 hvcsd->chars_in_buffer );
415 if (sent > 0) {
416 hvcsd->chars_in_buffer = 0;
417 /* wmb(); */
418 hvcsd->todo_mask &= ~(HVCS_TRY_WRITE);
419 /* wmb(); */
420
421 /*
422 * We are still obligated to deliver the data to the
423 * hypervisor even if the tty has been closed because
424 * we commited to delivering it. But don't try to wake
425 * a non-existent tty.
426 */
427 if (tty) {
428 tty_wakeup(tty);
429 }
430 }
431 }
432}
433
434static int hvcs_io(struct hvcs_struct *hvcsd)
435{
436 uint32_t unit_address;
437 struct tty_struct *tty;
438 char buf[HVCS_BUFF_LEN] __ALIGNED__;
439 unsigned long flags;
440 int got = 0;
441 int i;
442
443 spin_lock_irqsave(&hvcsd->lock, flags);
444
445 unit_address = hvcsd->vdev->unit_address;
446 tty = hvcsd->tty;
447
448 hvcs_try_write(hvcsd);
449
450 if (!tty || test_bit(TTY_THROTTLED, &tty->flags)) {
451 hvcsd->todo_mask &= ~(HVCS_READ_MASK);
452 goto bail;
453 } else if (!(hvcsd->todo_mask & (HVCS_READ_MASK)))
454 goto bail;
455
456 /* remove the read masks */
457 hvcsd->todo_mask &= ~(HVCS_READ_MASK);
458
459 if ((tty->flip.count + HVCS_BUFF_LEN) < TTY_FLIPBUF_SIZE) {
460 got = hvc_get_chars(unit_address,
461 &buf[0],
462 HVCS_BUFF_LEN);
463 for (i=0;got && i<got;i++)
464 tty_insert_flip_char(tty, buf[i], TTY_NORMAL);
465 }
466
467 /* Give the TTY time to process the data we just sent. */
468 if (got)
469 hvcsd->todo_mask |= HVCS_QUICK_READ;
470
471 spin_unlock_irqrestore(&hvcsd->lock, flags);
472 if (tty->flip.count) {
473 /* This is synch because tty->low_latency == 1 */
474 tty_flip_buffer_push(tty);
475 }
476
477 if (!got) {
478 /* Do this _after_ the flip_buffer_push */
479 spin_lock_irqsave(&hvcsd->lock, flags);
480 vio_enable_interrupts(hvcsd->vdev);
481 spin_unlock_irqrestore(&hvcsd->lock, flags);
482 }
483
484 return hvcsd->todo_mask;
485
486 bail:
487 spin_unlock_irqrestore(&hvcsd->lock, flags);
488 return hvcsd->todo_mask;
489}
490
491static int khvcsd(void *unused)
492{
493 struct hvcs_struct *hvcsd;
494 int hvcs_todo_mask;
495
496 __set_current_state(TASK_RUNNING);
497
498 do {
499 hvcs_todo_mask = 0;
500 hvcs_kicked = 0;
501 wmb();
502
503 spin_lock(&hvcs_structs_lock);
504 list_for_each_entry(hvcsd, &hvcs_structs, next) {
505 hvcs_todo_mask |= hvcs_io(hvcsd);
506 }
507 spin_unlock(&hvcs_structs_lock);
508
509 /*
510 * If any of the hvcs adapters want to try a write or quick read
511 * don't schedule(), yield a smidgen then execute the hvcs_io
512 * thread again for those that want the write.
513 */
514 if (hvcs_todo_mask & (HVCS_TRY_WRITE | HVCS_QUICK_READ)) {
515 yield();
516 continue;
517 }
518
519 set_current_state(TASK_INTERRUPTIBLE);
520 if (!hvcs_kicked)
521 schedule();
522 __set_current_state(TASK_RUNNING);
523 } while (!kthread_should_stop());
524
525 return 0;
526}
527
528static struct vio_device_id hvcs_driver_table[] __devinitdata= {
529 {"serial-server", "hvterm2"},
530 { NULL, }
531};
532MODULE_DEVICE_TABLE(vio, hvcs_driver_table);
533
534static void hvcs_return_index(int index)
535{
536 /* Paranoia check */
537 if (!hvcs_index_list)
538 return;
539 if (index < 0 || index >= hvcs_index_count)
540 return;
541 if (hvcs_index_list[index] == -1)
542 return;
543 else
544 hvcs_index_list[index] = -1;
545}
546
547/* callback when the kboject ref count reaches zero */
548static void destroy_hvcs_struct(struct kobject *kobj)
549{
550 struct hvcs_struct *hvcsd = from_kobj(kobj);
551 struct vio_dev *vdev;
552 unsigned long flags;
553
554 spin_lock(&hvcs_structs_lock);
555 spin_lock_irqsave(&hvcsd->lock, flags);
556
557 /* the list_del poisons the pointers */
558 list_del(&(hvcsd->next));
559
560 if (hvcsd->connected == 1) {
561 hvcs_partner_free(hvcsd);
562 printk(KERN_INFO "HVCS: Closed vty-server@%X and"
563 " partner vty@%X:%d connection.\n",
564 hvcsd->vdev->unit_address,
565 hvcsd->p_unit_address,
566 (uint32_t)hvcsd->p_partition_ID);
567 }
568 printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n",
569 hvcsd->vdev->unit_address);
570
571 vdev = hvcsd->vdev;
572 hvcsd->vdev = NULL;
573
574 hvcsd->p_unit_address = 0;
575 hvcsd->p_partition_ID = 0;
576 hvcs_return_index(hvcsd->index);
577 memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1);
578
579 spin_unlock_irqrestore(&hvcsd->lock, flags);
580 spin_unlock(&hvcs_structs_lock);
581
582 hvcs_remove_device_attrs(vdev);
583
584 kfree(hvcsd);
585}
586
587static struct kobj_type hvcs_kobj_type = {
588 .release = destroy_hvcs_struct,
589};
590
591static int hvcs_get_index(void)
592{
593 int i;
594 /* Paranoia check */
595 if (!hvcs_index_list) {
596 printk(KERN_ERR "HVCS: hvcs_index_list NOT valid!.\n");
597 return -EFAULT;
598 }
599 /* Find the numerically lowest first free index. */
600 for(i = 0; i < hvcs_index_count; i++) {
601 if (hvcs_index_list[i] == -1) {
602 hvcs_index_list[i] = 0;
603 return i;
604 }
605 }
606 return -1;
607}
608
609static int __devinit hvcs_probe(
610 struct vio_dev *dev,
611 const struct vio_device_id *id)
612{
613 struct hvcs_struct *hvcsd;
614 int index;
615
616 if (!dev || !id) {
617 printk(KERN_ERR "HVCS: probed with invalid parameter.\n");
618 return -EPERM;
619 }
620
621 /* early to avoid cleanup on failure */
622 index = hvcs_get_index();
623 if (index < 0) {
624 return -EFAULT;
625 }
626
627 hvcsd = kmalloc(sizeof(*hvcsd), GFP_KERNEL);
628 if (!hvcsd)
629 return -ENODEV;
630
631 /* hvcsd->tty is zeroed out with the memset */
632 memset(hvcsd, 0x00, sizeof(*hvcsd));
633
634 spin_lock_init(&hvcsd->lock);
635 /* Automatically incs the refcount the first time */
636 kobject_init(&hvcsd->kobj);
637 /* Set up the callback for terminating the hvcs_struct's life */
638 hvcsd->kobj.ktype = &hvcs_kobj_type;
639
640 hvcsd->vdev = dev;
641 dev->dev.driver_data = hvcsd;
642
643 hvcsd->index = index;
644
645 /* hvcsd->index = ++hvcs_struct_count; */
646 hvcsd->chars_in_buffer = 0;
647 hvcsd->todo_mask = 0;
648 hvcsd->connected = 0;
649
650 /*
651 * This will populate the hvcs_struct's partner info fields for the
652 * first time.
653 */
654 if (hvcs_get_pi(hvcsd)) {
655 printk(KERN_ERR "HVCS: Failed to fetch partner"
656 " info for vty-server@%X on device probe.\n",
657 hvcsd->vdev->unit_address);
658 }
659
660 /*
661 * If a user app opens a tty that corresponds to this vty-server before
662 * the hvcs_struct has been added to the devices list then the user app
663 * will get -ENODEV.
664 */
665
666 spin_lock(&hvcs_structs_lock);
667
668 list_add_tail(&(hvcsd->next), &hvcs_structs);
669
670 spin_unlock(&hvcs_structs_lock);
671
672 hvcs_create_device_attrs(hvcsd);
673
674 printk(KERN_INFO "HVCS: vty-server@%X added to the vio bus.\n", dev->unit_address);
675
676 /*
677 * DON'T enable interrupts here because there is no user to receive the
678 * data.
679 */
680 return 0;
681}
682
683static int __devexit hvcs_remove(struct vio_dev *dev)
684{
685 struct hvcs_struct *hvcsd = dev->dev.driver_data;
686 unsigned long flags;
687 struct kobject *kobjp;
688 struct tty_struct *tty;
689
690 if (!hvcsd)
691 return -ENODEV;
692
693 /* By this time the vty-server won't be getting any more interrups */
694
695 spin_lock_irqsave(&hvcsd->lock, flags);
696
697 tty = hvcsd->tty;
698
699 kobjp = &hvcsd->kobj;
700
701 spin_unlock_irqrestore(&hvcsd->lock, flags);
702
703 /*
704 * Let the last holder of this object cause it to be removed, which
705 * would probably be tty_hangup below.
706 */
707 kobject_put (kobjp);
708
709 /*
710 * The hangup is a scheduled function which will auto chain call
711 * hvcs_hangup. The tty should always be valid at this time unless a
712 * simultaneous tty close already cleaned up the hvcs_struct.
713 */
714 if (tty)
715 tty_hangup(tty);
716
717 printk(KERN_INFO "HVCS: vty-server@%X removed from the"
718 " vio bus.\n", dev->unit_address);
719 return 0;
720};
721
722static struct vio_driver hvcs_vio_driver = {
723 .name = hvcs_driver_name,
724 .id_table = hvcs_driver_table,
725 .probe = hvcs_probe,
726 .remove = hvcs_remove,
727};
728
729/* Only called from hvcs_get_pi please */
730static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd)
731{
732 int clclength;
733
734 hvcsd->p_unit_address = pi->unit_address;
735 hvcsd->p_partition_ID = pi->partition_ID;
736 clclength = strlen(&pi->location_code[0]);
737 if (clclength > HVCS_CLC_LENGTH)
738 clclength = HVCS_CLC_LENGTH;
739
740 /* copy the null-term char too */
741 strncpy(&hvcsd->p_location_code[0],
742 &pi->location_code[0], clclength + 1);
743}
744
745/*
746 * Traverse the list and add the partner info that is found to the hvcs_struct
747 * struct entry. NOTE: At this time I know that partner info will return a
748 * single entry but in the future there may be multiple partner info entries per
749 * vty-server and you'll want to zero out that list and reset it. If for some
750 * reason you have an old version of this driver but there IS more than one
751 * partner info then hvcsd->p_* will hold the last partner info data from the
752 * firmware query. A good way to update this code would be to replace the three
753 * partner info fields in hvcs_struct with a list of hvcs_partner_info
754 * instances.
755 *
756 * This function must be called with the hvcsd->lock held.
757 */
758static int hvcs_get_pi(struct hvcs_struct *hvcsd)
759{
760 struct hvcs_partner_info *pi;
761 uint32_t unit_address = hvcsd->vdev->unit_address;
762 struct list_head head;
763 int retval;
764
765 spin_lock(&hvcs_pi_lock);
766 if (!hvcs_pi_buff) {
767 spin_unlock(&hvcs_pi_lock);
768 return -EFAULT;
769 }
770 retval = hvcs_get_partner_info(unit_address, &head, hvcs_pi_buff);
771 spin_unlock(&hvcs_pi_lock);
772 if (retval) {
773 printk(KERN_ERR "HVCS: Failed to fetch partner"
774 " info for vty-server@%x.\n", unit_address);
775 return retval;
776 }
777
778 /* nixes the values if the partner vty went away */
779 hvcsd->p_unit_address = 0;
780 hvcsd->p_partition_ID = 0;
781
782 list_for_each_entry(pi, &head, node)
783 hvcs_set_pi(pi, hvcsd);
784
785 hvcs_free_partner_info(&head);
786 return 0;
787}
788
789/*
790 * This function is executed by the driver "rescan" sysfs entry. It shouldn't
791 * be executed elsewhere, in order to prevent deadlock issues.
792 */
793static int hvcs_rescan_devices_list(void)
794{
795 struct hvcs_struct *hvcsd;
796 unsigned long flags;
797
798 spin_lock(&hvcs_structs_lock);
799
800 list_for_each_entry(hvcsd, &hvcs_structs, next) {
801 spin_lock_irqsave(&hvcsd->lock, flags);
802 hvcs_get_pi(hvcsd);
803 spin_unlock_irqrestore(&hvcsd->lock, flags);
804 }
805
806 spin_unlock(&hvcs_structs_lock);
807
808 return 0;
809}
810
811/*
812 * Farm this off into its own function because it could be more complex once
813 * multiple partners support is added. This function should be called with
814 * the hvcsd->lock held.
815 */
816static int hvcs_has_pi(struct hvcs_struct *hvcsd)
817{
818 if ((!hvcsd->p_unit_address) || (!hvcsd->p_partition_ID))
819 return 0;
820 return 1;
821}
822
823/*
824 * NOTE: It is possible that the super admin removed a partner vty and then
825 * added a different vty as the new partner.
826 *
827 * This function must be called with the hvcsd->lock held.
828 */
829static int hvcs_partner_connect(struct hvcs_struct *hvcsd)
830{
831 int retval;
832 unsigned int unit_address = hvcsd->vdev->unit_address;
833
834 /*
835 * If there wasn't any pi when the device was added it doesn't meant
836 * there isn't any now. This driver isn't notified when a new partner
837 * vty is added to a vty-server so we discover changes on our own.
838 * Please see comments in hvcs_register_connection() for justification
839 * of this bizarre code.
840 */
841 retval = hvcs_register_connection(unit_address,
842 hvcsd->p_partition_ID,
843 hvcsd->p_unit_address);
844 if (!retval) {
845 hvcsd->connected = 1;
846 return 0;
847 } else if (retval != -EINVAL)
848 return retval;
849
850 /*
851 * As per the spec re-get the pi and try again if -EINVAL after the
852 * first connection attempt.
853 */
854 if (hvcs_get_pi(hvcsd))
855 return -ENOMEM;
856
857 if (!hvcs_has_pi(hvcsd))
858 return -ENODEV;
859
860 retval = hvcs_register_connection(unit_address,
861 hvcsd->p_partition_ID,
862 hvcsd->p_unit_address);
863 if (retval != -EINVAL) {
864 hvcsd->connected = 1;
865 return retval;
866 }
867
868 /*
869 * EBUSY is the most likely scenario though the vty could have been
870 * removed or there really could be an hcall error due to the parameter
871 * data but thanks to ambiguous firmware return codes we can't really
872 * tell.
873 */
874 printk(KERN_INFO "HVCS: vty-server or partner"
875 " vty is busy. Try again later.\n");
876 return -EBUSY;
877}
878
879/* This function must be called with the hvcsd->lock held */
880static void hvcs_partner_free(struct hvcs_struct *hvcsd)
881{
882 int retval;
883 do {
884 retval = hvcs_free_connection(hvcsd->vdev->unit_address);
885 } while (retval == -EBUSY);
886 hvcsd->connected = 0;
887}
888
889/* This helper function must be called WITHOUT the hvcsd->lock held */
890static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address,
891 unsigned int irq, struct vio_dev *vdev)
892{
893 unsigned long flags;
894 int rc;
895
896 /*
897 * It is possible that the vty-server was removed between the time that
898 * the conn was registered and now.
899 */
900 if (!(rc = request_irq(irq, &hvcs_handle_interrupt,
901 SA_INTERRUPT, "ibmhvcs", hvcsd))) {
902 /*
903 * It is possible the vty-server was removed after the irq was
904 * requested but before we have time to enable interrupts.
905 */
906 if (vio_enable_interrupts(vdev) == H_Success)
907 return 0;
908 else {
909 printk(KERN_ERR "HVCS: int enable failed for"
910 " vty-server@%X.\n", unit_address);
911 free_irq(irq, hvcsd);
912 }
913 } else
914 printk(KERN_ERR "HVCS: irq req failed for"
915 " vty-server@%X.\n", unit_address);
916
917 spin_lock_irqsave(&hvcsd->lock, flags);
918 hvcs_partner_free(hvcsd);
919 spin_unlock_irqrestore(&hvcsd->lock, flags);
920
921 return rc;
922
923}
924
925/*
926 * This always increments the kobject ref count if the call is successful.
927 * Please remember to dec when you are done with the instance.
928 *
929 * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when
930 * calling this function or you will get deadlock.
931 */
932struct hvcs_struct *hvcs_get_by_index(int index)
933{
934 struct hvcs_struct *hvcsd = NULL;
935 unsigned long flags;
936
937 spin_lock(&hvcs_structs_lock);
938 /* We can immediately discard OOB requests */
939 if (index >= 0 && index < HVCS_MAX_SERVER_ADAPTERS) {
940 list_for_each_entry(hvcsd, &hvcs_structs, next) {
941 spin_lock_irqsave(&hvcsd->lock, flags);
942 if (hvcsd->index == index) {
943 kobject_get(&hvcsd->kobj);
944 spin_unlock_irqrestore(&hvcsd->lock, flags);
945 spin_unlock(&hvcs_structs_lock);
946 return hvcsd;
947 }
948 spin_unlock_irqrestore(&hvcsd->lock, flags);
949 }
950 hvcsd = NULL;
951 }
952
953 spin_unlock(&hvcs_structs_lock);
954 return hvcsd;
955}
956
957/*
958 * This is invoked via the tty_open interface when a user app connects to the
959 * /dev node.
960 */
961static int hvcs_open(struct tty_struct *tty, struct file *filp)
962{
963 struct hvcs_struct *hvcsd;
964 int rc, retval = 0;
965 unsigned long flags;
966 unsigned int irq;
967 struct vio_dev *vdev;
968 unsigned long unit_address;
969 struct kobject *kobjp;
970
971 if (tty->driver_data)
972 goto fast_open;
973
974 /*
975 * Is there a vty-server that shares the same index?
976 * This function increments the kobject index.
977 */
978 if (!(hvcsd = hvcs_get_by_index(tty->index))) {
979 printk(KERN_WARNING "HVCS: open failed, no device associated"
980 " with tty->index %d.\n", tty->index);
981 return -ENODEV;
982 }
983
984 spin_lock_irqsave(&hvcsd->lock, flags);
985
986 if (hvcsd->connected == 0)
987 if ((retval = hvcs_partner_connect(hvcsd)))
988 goto error_release;
989
990 hvcsd->open_count = 1;
991 hvcsd->tty = tty;
992 tty->driver_data = hvcsd;
993
994 /*
995 * Set this driver to low latency so that we actually have a chance at
996 * catching a throttled TTY after we flip_buffer_push. Otherwise the
997 * flush_to_async may not execute until after the kernel_thread has
998 * yielded and resumed the next flip_buffer_push resulting in data
999 * loss.
1000 */
1001 tty->low_latency = 1;
1002
1003 memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN);
1004
1005 /*
1006 * Save these in the spinlock for the enable operations that need them
1007 * outside of the spinlock.
1008 */
1009 irq = hvcsd->vdev->irq;
1010 vdev = hvcsd->vdev;
1011 unit_address = hvcsd->vdev->unit_address;
1012
1013 hvcsd->todo_mask |= HVCS_SCHED_READ;
1014 spin_unlock_irqrestore(&hvcsd->lock, flags);
1015
1016 /*
1017 * This must be done outside of the spinlock because it requests irqs
1018 * and will grab the spinlock and free the connection if it fails.
1019 */
1020 if (((rc = hvcs_enable_device(hvcsd, unit_address, irq, vdev)))) {
1021 kobject_put(&hvcsd->kobj);
1022 printk(KERN_WARNING "HVCS: enable device failed.\n");
1023 return rc;
1024 }
1025
1026 goto open_success;
1027
1028fast_open:
1029 hvcsd = tty->driver_data;
1030
1031 spin_lock_irqsave(&hvcsd->lock, flags);
1032 if (!kobject_get(&hvcsd->kobj)) {
1033 spin_unlock_irqrestore(&hvcsd->lock, flags);
1034 printk(KERN_ERR "HVCS: Kobject of open"
1035 " hvcs doesn't exist.\n");
1036 return -EFAULT; /* Is this the right return value? */
1037 }
1038
1039 hvcsd->open_count++;
1040
1041 hvcsd->todo_mask |= HVCS_SCHED_READ;
1042 spin_unlock_irqrestore(&hvcsd->lock, flags);
1043open_success:
1044 hvcs_kick();
1045
1046 printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n",
1047 hvcsd->vdev->unit_address );
1048
1049 return 0;
1050
1051error_release:
1052 kobjp = &hvcsd->kobj;
1053 spin_unlock_irqrestore(&hvcsd->lock, flags);
1054 kobject_put(&hvcsd->kobj);
1055
1056 printk(KERN_WARNING "HVCS: partner connect failed.\n");
1057 return retval;
1058}
1059
1060static void hvcs_close(struct tty_struct *tty, struct file *filp)
1061{
1062 struct hvcs_struct *hvcsd;
1063 unsigned long flags;
1064 struct kobject *kobjp;
1065 int irq = NO_IRQ;
1066
1067 /*
1068 * Is someone trying to close the file associated with this device after
1069 * we have hung up? If so tty->driver_data wouldn't be valid.
1070 */
1071 if (tty_hung_up_p(filp))
1072 return;
1073
1074 /*
1075 * No driver_data means that this close was probably issued after a
1076 * failed hvcs_open by the tty layer's release_dev() api and we can just
1077 * exit cleanly.
1078 */
1079 if (!tty->driver_data)
1080 return;
1081
1082 hvcsd = tty->driver_data;
1083
1084 spin_lock_irqsave(&hvcsd->lock, flags);
1085 kobjp = &hvcsd->kobj;
1086 if (--hvcsd->open_count == 0) {
1087
1088 vio_disable_interrupts(hvcsd->vdev);
1089
1090 /*
1091 * NULL this early so that the kernel_thread doesn't try to
1092 * execute any operations on the TTY even though it is obligated
1093 * to deliver any pending I/O to the hypervisor.
1094 */
1095 hvcsd->tty = NULL;
1096
1097 irq = hvcsd->vdev->irq;
1098 spin_unlock_irqrestore(&hvcsd->lock, flags);
1099
1100 tty_wait_until_sent(tty, HVCS_CLOSE_WAIT);
1101
1102 /*
1103 * This line is important because it tells hvcs_open that this
1104 * device needs to be re-configured the next time hvcs_open is
1105 * called.
1106 */
1107 tty->driver_data = NULL;
1108
1109 free_irq(irq, hvcsd);
1110 kobject_put(kobjp);
1111 return;
1112 } else if (hvcsd->open_count < 0) {
1113 printk(KERN_ERR "HVCS: vty-server@%X open_count: %d"
1114 " is missmanaged.\n",
1115 hvcsd->vdev->unit_address, hvcsd->open_count);
1116 }
1117
1118 spin_unlock_irqrestore(&hvcsd->lock, flags);
1119 kobject_put(kobjp);
1120}
1121
1122static void hvcs_hangup(struct tty_struct * tty)
1123{
1124 struct hvcs_struct *hvcsd = tty->driver_data;
1125 unsigned long flags;
1126 int temp_open_count;
1127 struct kobject *kobjp;
1128 int irq = NO_IRQ;
1129
1130 spin_lock_irqsave(&hvcsd->lock, flags);
1131 /* Preserve this so that we know how many kobject refs to put */
1132 temp_open_count = hvcsd->open_count;
1133
1134 /*
1135 * Don't kobject put inside the spinlock because the destruction
1136 * callback may use the spinlock and it may get called before the
1137 * spinlock has been released. Get a pointer to the kobject and
1138 * kobject_put on that after releasing the spinlock.
1139 */
1140 kobjp = &hvcsd->kobj;
1141
1142 vio_disable_interrupts(hvcsd->vdev);
1143
1144 hvcsd->todo_mask = 0;
1145
1146 /* I don't think the tty needs the hvcs_struct pointer after a hangup */
1147 hvcsd->tty->driver_data = NULL;
1148 hvcsd->tty = NULL;
1149
1150 hvcsd->open_count = 0;
1151
1152 /* This will drop any buffered data on the floor which is OK in a hangup
1153 * scenario. */
1154 memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN);
1155 hvcsd->chars_in_buffer = 0;
1156
1157 irq = hvcsd->vdev->irq;
1158
1159 spin_unlock_irqrestore(&hvcsd->lock, flags);
1160
1161 free_irq(irq, hvcsd);
1162
1163 /*
1164 * We need to kobject_put() for every open_count we have since the
1165 * tty_hangup() function doesn't invoke a close per open connection on a
1166 * non-console device.
1167 */
1168 while(temp_open_count) {
1169 --temp_open_count;
1170 /*
1171 * The final put will trigger destruction of the hvcs_struct.
1172 * NOTE: If this hangup was signaled from user space then the
1173 * final put will never happen.
1174 */
1175 kobject_put(kobjp);
1176 }
1177}
1178
1179/*
1180 * NOTE: This is almost always from_user since user level apps interact with the
1181 * /dev nodes. I'm trusting that if hvcs_write gets called and interrupted by
1182 * hvcs_remove (which removes the target device and executes tty_hangup()) that
1183 * tty_hangup will allow hvcs_write time to complete execution before it
1184 * terminates our device.
1185 */
1186static int hvcs_write(struct tty_struct *tty,
1187 const unsigned char *buf, int count)
1188{
1189 struct hvcs_struct *hvcsd = tty->driver_data;
1190 unsigned int unit_address;
1191 const unsigned char *charbuf;
1192 unsigned long flags;
1193 int total_sent = 0;
1194 int tosend = 0;
1195 int result = 0;
1196
1197 /*
1198 * If they don't check the return code off of their open they may
1199 * attempt this even if there is no connected device.
1200 */
1201 if (!hvcsd)
1202 return -ENODEV;
1203
1204 /* Reasonable size to prevent user level flooding */
1205 if (count > HVCS_MAX_FROM_USER) {
1206 printk(KERN_WARNING "HVCS write: count being truncated to"
1207 " HVCS_MAX_FROM_USER.\n");
1208 count = HVCS_MAX_FROM_USER;
1209 }
1210
1211 charbuf = buf;
1212
1213 spin_lock_irqsave(&hvcsd->lock, flags);
1214
1215 /*
1216 * Somehow an open succedded but the device was removed or the
1217 * connection terminated between the vty-server and partner vty during
1218 * the middle of a write operation? This is a crummy place to do this
1219 * but we want to keep it all in the spinlock.
1220 */
1221 if (hvcsd->open_count <= 0) {
1222 spin_unlock_irqrestore(&hvcsd->lock, flags);
1223 return -ENODEV;
1224 }
1225
1226 unit_address = hvcsd->vdev->unit_address;
1227
1228 while (count > 0) {
1229 tosend = min(count, (HVCS_BUFF_LEN - hvcsd->chars_in_buffer));
1230 /*
1231 * No more space, this probably means that the last call to
1232 * hvcs_write() didn't succeed and the buffer was filled up.
1233 */
1234 if (!tosend)
1235 break;
1236
1237 memcpy(&hvcsd->buffer[hvcsd->chars_in_buffer],
1238 &charbuf[total_sent],
1239 tosend);
1240
1241 hvcsd->chars_in_buffer += tosend;
1242
1243 result = 0;
1244
1245 /*
1246 * If this is true then we don't want to try writing to the
1247 * hypervisor because that is the kernel_threads job now. We'll
1248 * just add to the buffer.
1249 */
1250 if (!(hvcsd->todo_mask & HVCS_TRY_WRITE))
1251 /* won't send partial writes */
1252 result = hvc_put_chars(unit_address,
1253 &hvcsd->buffer[0],
1254 hvcsd->chars_in_buffer);
1255
1256 /*
1257 * Since we know we have enough room in hvcsd->buffer for
1258 * tosend we record that it was sent regardless of whether the
1259 * hypervisor actually took it because we have it buffered.
1260 */
1261 total_sent+=tosend;
1262 count-=tosend;
1263 if (result == 0) {
1264 hvcsd->todo_mask |= HVCS_TRY_WRITE;
1265 hvcs_kick();
1266 break;
1267 }
1268
1269 hvcsd->chars_in_buffer = 0;
1270 /*
1271 * Test after the chars_in_buffer reset otherwise this could
1272 * deadlock our writes if hvc_put_chars fails.
1273 */
1274 if (result < 0)
1275 break;
1276 }
1277
1278 spin_unlock_irqrestore(&hvcsd->lock, flags);
1279
1280 if (result == -1)
1281 return -EIO;
1282 else
1283 return total_sent;
1284}
1285
1286/*
1287 * This is really asking how much can we guarentee that we can send or that we
1288 * absolutely WILL BUFFER if we can't send it. This driver MUST honor the
1289 * return value, hence the reason for hvcs_struct buffering.
1290 */
1291static int hvcs_write_room(struct tty_struct *tty)
1292{
1293 struct hvcs_struct *hvcsd = tty->driver_data;
1294
1295 if (!hvcsd || hvcsd->open_count <= 0)
1296 return 0;
1297
1298 return HVCS_BUFF_LEN - hvcsd->chars_in_buffer;
1299}
1300
1301static int hvcs_chars_in_buffer(struct tty_struct *tty)
1302{
1303 struct hvcs_struct *hvcsd = tty->driver_data;
1304
1305 return hvcsd->chars_in_buffer;
1306}
1307
1308static struct tty_operations hvcs_ops = {
1309 .open = hvcs_open,
1310 .close = hvcs_close,
1311 .hangup = hvcs_hangup,
1312 .write = hvcs_write,
1313 .write_room = hvcs_write_room,
1314 .chars_in_buffer = hvcs_chars_in_buffer,
1315 .unthrottle = hvcs_unthrottle,
1316 .throttle = hvcs_throttle,
1317};
1318
1319static int hvcs_alloc_index_list(int n)
1320{
1321 int i;
1322 hvcs_index_list = kmalloc(n * sizeof(hvcs_index_count),GFP_KERNEL);
1323 if (!hvcs_index_list)
1324 return -ENOMEM;
1325 hvcs_index_count = n;
1326 for(i = 0; i < hvcs_index_count; i++)
1327 hvcs_index_list[i] = -1;
1328 return 0;
1329}
1330
1331static void hvcs_free_index_list(void)
1332{
1333 /* Paranoia check to be thorough. */
1334 if (hvcs_index_list) {
1335 kfree(hvcs_index_list);
1336 hvcs_index_list = NULL;
1337 hvcs_index_count = 0;
1338 }
1339}
1340
1341static int __init hvcs_module_init(void)
1342{
1343 int rc;
1344 int num_ttys_to_alloc;
1345
1346 printk(KERN_INFO "Initializing %s\n", hvcs_driver_string);
1347
1348 /* Has the user specified an overload with an insmod param? */
1349 if (hvcs_parm_num_devs <= 0 ||
1350 (hvcs_parm_num_devs > HVCS_MAX_SERVER_ADAPTERS)) {
1351 num_ttys_to_alloc = HVCS_DEFAULT_SERVER_ADAPTERS;
1352 } else
1353 num_ttys_to_alloc = hvcs_parm_num_devs;
1354
1355 hvcs_tty_driver = alloc_tty_driver(num_ttys_to_alloc);
1356 if (!hvcs_tty_driver)
1357 return -ENOMEM;
1358
1359 if (hvcs_alloc_index_list(num_ttys_to_alloc))
1360 return -ENOMEM;
1361
1362 hvcs_tty_driver->owner = THIS_MODULE;
1363
1364 hvcs_tty_driver->driver_name = hvcs_driver_name;
1365 hvcs_tty_driver->name = hvcs_device_node;
1366 hvcs_tty_driver->devfs_name = hvcs_device_node;
1367
1368 /*
1369 * We'll let the system assign us a major number, indicated by leaving
1370 * it blank.
1371 */
1372
1373 hvcs_tty_driver->minor_start = HVCS_MINOR_START;
1374 hvcs_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1375
1376 /*
1377 * We role our own so that we DONT ECHO. We can't echo because the
1378 * device we are connecting to already echoes by default and this would
1379 * throw us into a horrible recursive echo-echo-echo loop.
1380 */
1381 hvcs_tty_driver->init_termios = hvcs_tty_termios;
1382 hvcs_tty_driver->flags = TTY_DRIVER_REAL_RAW;
1383
1384 tty_set_operations(hvcs_tty_driver, &hvcs_ops);
1385
1386 /*
1387 * The following call will result in sysfs entries that denote the
1388 * dynamically assigned major and minor numbers for our devices.
1389 */
1390 if (tty_register_driver(hvcs_tty_driver)) {
1391 printk(KERN_ERR "HVCS: registration "
1392 " as a tty driver failed.\n");
1393 hvcs_free_index_list();
1394 put_tty_driver(hvcs_tty_driver);
1395 return -EIO;
1396 }
1397
1398 hvcs_pi_buff = kmalloc(PAGE_SIZE, GFP_KERNEL);
1399 if (!hvcs_pi_buff) {
1400 tty_unregister_driver(hvcs_tty_driver);
1401 hvcs_free_index_list();
1402 put_tty_driver(hvcs_tty_driver);
1403 return -ENOMEM;
1404 }
1405
1406 hvcs_task = kthread_run(khvcsd, NULL, "khvcsd");
1407 if (IS_ERR(hvcs_task)) {
1408 printk(KERN_ERR "HVCS: khvcsd creation failed. Driver not loaded.\n");
1409 kfree(hvcs_pi_buff);
1410 tty_unregister_driver(hvcs_tty_driver);
1411 hvcs_free_index_list();
1412 put_tty_driver(hvcs_tty_driver);
1413 return -EIO;
1414 }
1415
1416 rc = vio_register_driver(&hvcs_vio_driver);
1417
1418 /*
1419 * This needs to be done AFTER the vio_register_driver() call or else
1420 * the kobjects won't be initialized properly.
1421 */
1422 hvcs_create_driver_attrs();
1423
1424 printk(KERN_INFO "HVCS: driver module inserted.\n");
1425
1426 return rc;
1427}
1428
1429static void __exit hvcs_module_exit(void)
1430{
1431 /*
1432 * This driver receives hvcs_remove callbacks for each device upon
1433 * module removal.
1434 */
1435
1436 /*
1437 * This synchronous operation will wake the khvcsd kthread if it is
1438 * asleep and will return when khvcsd has terminated.
1439 */
1440 kthread_stop(hvcs_task);
1441
1442 spin_lock(&hvcs_pi_lock);
1443 kfree(hvcs_pi_buff);
1444 hvcs_pi_buff = NULL;
1445 spin_unlock(&hvcs_pi_lock);
1446
1447 hvcs_remove_driver_attrs();
1448
1449 vio_unregister_driver(&hvcs_vio_driver);
1450
1451 tty_unregister_driver(hvcs_tty_driver);
1452
1453 hvcs_free_index_list();
1454
1455 put_tty_driver(hvcs_tty_driver);
1456
1457 printk(KERN_INFO "HVCS: driver module removed.\n");
1458}
1459
1460module_init(hvcs_module_init);
1461module_exit(hvcs_module_exit);
1462
1463static inline struct hvcs_struct *from_vio_dev(struct vio_dev *viod)
1464{
1465 return viod->dev.driver_data;
1466}
1467/* The sysfs interface for the driver and devices */
1468
1469static ssize_t hvcs_partner_vtys_show(struct device *dev, char *buf)
1470{
1471 struct vio_dev *viod = to_vio_dev(dev);
1472 struct hvcs_struct *hvcsd = from_vio_dev(viod);
1473 unsigned long flags;
1474 int retval;
1475
1476 spin_lock_irqsave(&hvcsd->lock, flags);
1477 retval = sprintf(buf, "%X\n", hvcsd->p_unit_address);
1478 spin_unlock_irqrestore(&hvcsd->lock, flags);
1479 return retval;
1480}
1481static DEVICE_ATTR(partner_vtys, S_IRUGO, hvcs_partner_vtys_show, NULL);
1482
1483static ssize_t hvcs_partner_clcs_show(struct device *dev, char *buf)
1484{
1485 struct vio_dev *viod = to_vio_dev(dev);
1486 struct hvcs_struct *hvcsd = from_vio_dev(viod);
1487 unsigned long flags;
1488 int retval;
1489
1490 spin_lock_irqsave(&hvcsd->lock, flags);
1491 retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]);
1492 spin_unlock_irqrestore(&hvcsd->lock, flags);
1493 return retval;
1494}
1495static DEVICE_ATTR(partner_clcs, S_IRUGO, hvcs_partner_clcs_show, NULL);
1496
1497static ssize_t hvcs_current_vty_store(struct device *dev, const char * buf,
1498 size_t count)
1499{
1500 /*
1501 * Don't need this feature at the present time because firmware doesn't
1502 * yet support multiple partners.
1503 */
1504 printk(KERN_INFO "HVCS: Denied current_vty change: -EPERM.\n");
1505 return -EPERM;
1506}
1507
1508static ssize_t hvcs_current_vty_show(struct device *dev, char *buf)
1509{
1510 struct vio_dev *viod = to_vio_dev(dev);
1511 struct hvcs_struct *hvcsd = from_vio_dev(viod);
1512 unsigned long flags;
1513 int retval;
1514
1515 spin_lock_irqsave(&hvcsd->lock, flags);
1516 retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]);
1517 spin_unlock_irqrestore(&hvcsd->lock, flags);
1518 return retval;
1519}
1520
1521static DEVICE_ATTR(current_vty,
1522 S_IRUGO | S_IWUSR, hvcs_current_vty_show, hvcs_current_vty_store);
1523
1524static ssize_t hvcs_vterm_state_store(struct device *dev, const char *buf,
1525 size_t count)
1526{
1527 struct vio_dev *viod = to_vio_dev(dev);
1528 struct hvcs_struct *hvcsd = from_vio_dev(viod);
1529 unsigned long flags;
1530
1531 /* writing a '0' to this sysfs entry will result in the disconnect. */
1532 if (simple_strtol(buf, NULL, 0) != 0)
1533 return -EINVAL;
1534
1535 spin_lock_irqsave(&hvcsd->lock, flags);
1536
1537 if (hvcsd->open_count > 0) {
1538 spin_unlock_irqrestore(&hvcsd->lock, flags);
1539 printk(KERN_INFO "HVCS: vterm state unchanged. "
1540 "The hvcs device node is still in use.\n");
1541 return -EPERM;
1542 }
1543
1544 if (hvcsd->connected == 0) {
1545 spin_unlock_irqrestore(&hvcsd->lock, flags);
1546 printk(KERN_INFO "HVCS: vterm state unchanged. The"
1547 " vty-server is not connected to a vty.\n");
1548 return -EPERM;
1549 }
1550
1551 hvcs_partner_free(hvcsd);
1552 printk(KERN_INFO "HVCS: Closed vty-server@%X and"
1553 " partner vty@%X:%d connection.\n",
1554 hvcsd->vdev->unit_address,
1555 hvcsd->p_unit_address,
1556 (uint32_t)hvcsd->p_partition_ID);
1557
1558 spin_unlock_irqrestore(&hvcsd->lock, flags);
1559 return count;
1560}
1561
1562static ssize_t hvcs_vterm_state_show(struct device *dev, char *buf)
1563{
1564 struct vio_dev *viod = to_vio_dev(dev);
1565 struct hvcs_struct *hvcsd = from_vio_dev(viod);
1566 unsigned long flags;
1567 int retval;
1568
1569 spin_lock_irqsave(&hvcsd->lock, flags);
1570 retval = sprintf(buf, "%d\n", hvcsd->connected);
1571 spin_unlock_irqrestore(&hvcsd->lock, flags);
1572 return retval;
1573}
1574static DEVICE_ATTR(vterm_state, S_IRUGO | S_IWUSR,
1575 hvcs_vterm_state_show, hvcs_vterm_state_store);
1576
1577static ssize_t hvcs_index_show(struct device *dev, char *buf)
1578{
1579 struct vio_dev *viod = to_vio_dev(dev);
1580 struct hvcs_struct *hvcsd = from_vio_dev(viod);
1581 unsigned long flags;
1582 int retval;
1583
1584 spin_lock_irqsave(&hvcsd->lock, flags);
1585 retval = sprintf(buf, "%d\n", hvcsd->index);
1586 spin_unlock_irqrestore(&hvcsd->lock, flags);
1587 return retval;
1588}
1589
1590static DEVICE_ATTR(index, S_IRUGO, hvcs_index_show, NULL);
1591
1592static struct attribute *hvcs_attrs[] = {
1593 &dev_attr_partner_vtys.attr,
1594 &dev_attr_partner_clcs.attr,
1595 &dev_attr_current_vty.attr,
1596 &dev_attr_vterm_state.attr,
1597 &dev_attr_index.attr,
1598 NULL,
1599};
1600
1601static struct attribute_group hvcs_attr_group = {
1602 .attrs = hvcs_attrs,
1603};
1604
1605static void hvcs_create_device_attrs(struct hvcs_struct *hvcsd)
1606{
1607 struct vio_dev *vdev = hvcsd->vdev;
1608 sysfs_create_group(&vdev->dev.kobj, &hvcs_attr_group);
1609}
1610
1611static void hvcs_remove_device_attrs(struct vio_dev *vdev)
1612{
1613 sysfs_remove_group(&vdev->dev.kobj, &hvcs_attr_group);
1614}
1615
1616static ssize_t hvcs_rescan_show(struct device_driver *ddp, char *buf)
1617{
1618 /* A 1 means it is updating, a 0 means it is done updating */
1619 return snprintf(buf, PAGE_SIZE, "%d\n", hvcs_rescan_status);
1620}
1621
1622static ssize_t hvcs_rescan_store(struct device_driver *ddp, const char * buf,
1623 size_t count)
1624{
1625 if ((simple_strtol(buf, NULL, 0) != 1)
1626 && (hvcs_rescan_status != 0))
1627 return -EINVAL;
1628
1629 hvcs_rescan_status = 1;
1630 printk(KERN_INFO "HVCS: rescanning partner info for all"
1631 " vty-servers.\n");
1632 hvcs_rescan_devices_list();
1633 hvcs_rescan_status = 0;
1634 return count;
1635}
1636static DRIVER_ATTR(rescan,
1637 S_IRUGO | S_IWUSR, hvcs_rescan_show, hvcs_rescan_store);
1638
1639static void hvcs_create_driver_attrs(void)
1640{
1641 struct device_driver *driverfs = &(hvcs_vio_driver.driver);
1642 driver_create_file(driverfs, &driver_attr_rescan);
1643}
1644
1645static void hvcs_remove_driver_attrs(void)
1646{
1647 struct device_driver *driverfs = &(hvcs_vio_driver.driver);
1648 driver_remove_file(driverfs, &driver_attr_rescan);
1649}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-17 20:12:24 -0500