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1da177e4 LT |
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 | |
2ef9481e | 121 | * include/asm-powerpc/hvcserver.h |
1da177e4 LT |
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 | ||
133 | MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>"); | |
134 | MODULE_DESCRIPTION("IBM hvcs (Hypervisor Virtual Console Server) Driver"); | |
135 | MODULE_LICENSE("GPL"); | |
136 | MODULE_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. | |
2ef9481e JM |
171 | * We load up those 2 registers (in arch/powerpc/platforms/pseries/hvconsole.c) |
172 | * by casting char[16] to long[2]. It would work without __ALIGNED__, but a | |
173 | * little (tiny) bit slower because an unaligned load is slower than aligned | |
174 | * load. | |
1da177e4 LT |
175 | */ |
176 | #define __ALIGNED__ __attribute__((__aligned__(8))) | |
177 | ||
178 | /* | |
179 | * How much data can firmware send with each hvc_put_chars()? Maybe this | |
180 | * should be moved into an architecture specific area. | |
181 | */ | |
182 | #define HVCS_BUFF_LEN 16 | |
183 | ||
184 | /* | |
185 | * This is the maximum amount of data we'll let the user send us (hvcs_write) at | |
186 | * once in a chunk as a sanity check. | |
187 | */ | |
188 | #define HVCS_MAX_FROM_USER 4096 | |
189 | ||
190 | /* | |
191 | * Be careful when adding flags to this line discipline. Don't add anything | |
192 | * that will cause echoing or we'll go into recursive loop echoing chars back | |
193 | * and forth with the console drivers. | |
194 | */ | |
606d099c | 195 | static struct ktermios hvcs_tty_termios = { |
1da177e4 LT |
196 | .c_iflag = IGNBRK | IGNPAR, |
197 | .c_oflag = OPOST, | |
198 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
606d099c AC |
199 | .c_cc = INIT_C_CC, |
200 | .c_ispeed = 38400, | |
201 | .c_ospeed = 38400 | |
1da177e4 LT |
202 | }; |
203 | ||
204 | /* | |
205 | * This value is used to take the place of a command line parameter when the | |
206 | * module is inserted. It starts as -1 and stays as such if the user doesn't | |
207 | * specify a module insmod parameter. If they DO specify one then it is set to | |
208 | * the value of the integer passed in. | |
209 | */ | |
210 | static int hvcs_parm_num_devs = -1; | |
211 | module_param(hvcs_parm_num_devs, int, 0); | |
212 | ||
213 | char hvcs_driver_name[] = "hvcs"; | |
214 | char hvcs_device_node[] = "hvcs"; | |
215 | char hvcs_driver_string[] | |
216 | = "IBM hvcs (Hypervisor Virtual Console Server) Driver"; | |
217 | ||
218 | /* Status of partner info rescan triggered via sysfs. */ | |
219 | static int hvcs_rescan_status; | |
220 | ||
221 | static struct tty_driver *hvcs_tty_driver; | |
222 | ||
223 | /* | |
224 | * In order to be somewhat sane this driver always associates the hvcs_struct | |
225 | * index element with the numerically equal tty->index. This means that a | |
226 | * hotplugged vty-server adapter will always map to the lowest index valued | |
227 | * device node. If vty-servers were hotplug removed from the system and then | |
228 | * new ones added the new vty-server may have the largest slot number of all | |
229 | * the vty-server adapters in the partition but it may have the lowest dev node | |
230 | * index of all the adapters due to the hole left by the hotplug removed | |
231 | * adapter. There are a set of functions provided to get the lowest index for | |
232 | * a new device as well as return the index to the list. This list is allocated | |
233 | * with a number of elements equal to the number of device nodes requested when | |
234 | * the module was inserted. | |
235 | */ | |
236 | static int *hvcs_index_list; | |
237 | ||
238 | /* | |
239 | * How large is the list? This is kept for traversal since the list is | |
240 | * dynamically created. | |
241 | */ | |
242 | static int hvcs_index_count; | |
243 | ||
244 | /* | |
245 | * Used by the khvcsd to pick up I/O operations when the kernel_thread is | |
246 | * already awake but potentially shifted to TASK_INTERRUPTIBLE state. | |
247 | */ | |
248 | static int hvcs_kicked; | |
249 | ||
250 | /* | |
251 | * Use by the kthread construct for task operations like waking the sleeping | |
252 | * thread and stopping the kthread. | |
253 | */ | |
254 | static struct task_struct *hvcs_task; | |
255 | ||
256 | /* | |
257 | * We allocate this for the use of all of the hvcs_structs when they fetch | |
258 | * partner info. | |
259 | */ | |
260 | static unsigned long *hvcs_pi_buff; | |
261 | ||
262 | /* Only allow one hvcs_struct to use the hvcs_pi_buff at a time. */ | |
263 | static DEFINE_SPINLOCK(hvcs_pi_lock); | |
264 | ||
265 | /* One vty-server per hvcs_struct */ | |
266 | struct hvcs_struct { | |
267 | spinlock_t lock; | |
268 | ||
269 | /* | |
270 | * This index identifies this hvcs device as the complement to a | |
271 | * specific tty index. | |
272 | */ | |
273 | unsigned int index; | |
274 | ||
275 | struct tty_struct *tty; | |
276 | unsigned int open_count; | |
277 | ||
278 | /* | |
279 | * Used to tell the driver kernel_thread what operations need to take | |
280 | * place upon this hvcs_struct instance. | |
281 | */ | |
282 | int todo_mask; | |
283 | ||
284 | /* | |
285 | * This buffer is required so that when hvcs_write_room() reports that | |
286 | * it can send HVCS_BUFF_LEN characters that it will buffer the full | |
287 | * HVCS_BUFF_LEN characters if need be. This is essential for opost | |
288 | * writes since they do not do high level buffering and expect to be | |
289 | * able to send what the driver commits to sending buffering | |
290 | * [e.g. tab to space conversions in n_tty.c opost()]. | |
291 | */ | |
292 | char buffer[HVCS_BUFF_LEN]; | |
293 | int chars_in_buffer; | |
294 | ||
295 | /* | |
296 | * Any variable below the kobject is valid before a tty is connected and | |
297 | * stays valid after the tty is disconnected. These shouldn't be | |
298 | * whacked until the koject refcount reaches zero though some entries | |
299 | * may be changed via sysfs initiatives. | |
300 | */ | |
301 | struct kobject kobj; /* ref count & hvcs_struct lifetime */ | |
302 | int connected; /* is the vty-server currently connected to a vty? */ | |
303 | uint32_t p_unit_address; /* partner unit address */ | |
304 | uint32_t p_partition_ID; /* partner partition ID */ | |
305 | char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */ | |
306 | struct list_head next; /* list management */ | |
307 | struct vio_dev *vdev; | |
308 | }; | |
309 | ||
310 | /* Required to back map a kobject to its containing object */ | |
311 | #define from_kobj(kobj) container_of(kobj, struct hvcs_struct, kobj) | |
312 | ||
313 | static struct list_head hvcs_structs = LIST_HEAD_INIT(hvcs_structs); | |
314 | static DEFINE_SPINLOCK(hvcs_structs_lock); | |
315 | ||
316 | static void hvcs_unthrottle(struct tty_struct *tty); | |
317 | static void hvcs_throttle(struct tty_struct *tty); | |
7d12e780 | 318 | static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance); |
1da177e4 LT |
319 | |
320 | static int hvcs_write(struct tty_struct *tty, | |
321 | const unsigned char *buf, int count); | |
322 | static int hvcs_write_room(struct tty_struct *tty); | |
323 | static int hvcs_chars_in_buffer(struct tty_struct *tty); | |
324 | ||
325 | static int hvcs_has_pi(struct hvcs_struct *hvcsd); | |
326 | static void hvcs_set_pi(struct hvcs_partner_info *pi, | |
327 | struct hvcs_struct *hvcsd); | |
328 | static int hvcs_get_pi(struct hvcs_struct *hvcsd); | |
329 | static int hvcs_rescan_devices_list(void); | |
330 | ||
331 | static int hvcs_partner_connect(struct hvcs_struct *hvcsd); | |
332 | static void hvcs_partner_free(struct hvcs_struct *hvcsd); | |
333 | ||
334 | static int hvcs_enable_device(struct hvcs_struct *hvcsd, | |
335 | uint32_t unit_address, unsigned int irq, struct vio_dev *dev); | |
336 | ||
337 | static void destroy_hvcs_struct(struct kobject *kobj); | |
338 | static int hvcs_open(struct tty_struct *tty, struct file *filp); | |
339 | static void hvcs_close(struct tty_struct *tty, struct file *filp); | |
340 | static void hvcs_hangup(struct tty_struct * tty); | |
341 | ||
1da177e4 LT |
342 | static int __devinit hvcs_probe(struct vio_dev *dev, |
343 | const struct vio_device_id *id); | |
344 | static int __devexit hvcs_remove(struct vio_dev *dev); | |
345 | static int __init hvcs_module_init(void); | |
346 | static void __exit hvcs_module_exit(void); | |
347 | ||
348 | #define HVCS_SCHED_READ 0x00000001 | |
349 | #define HVCS_QUICK_READ 0x00000002 | |
350 | #define HVCS_TRY_WRITE 0x00000004 | |
351 | #define HVCS_READ_MASK (HVCS_SCHED_READ | HVCS_QUICK_READ) | |
352 | ||
c15bb296 LV |
353 | static inline struct hvcs_struct *from_vio_dev(struct vio_dev *viod) |
354 | { | |
355 | return viod->dev.driver_data; | |
356 | } | |
357 | /* The sysfs interface for the driver and devices */ | |
358 | ||
359 | static ssize_t hvcs_partner_vtys_show(struct device *dev, struct device_attribute *attr, char *buf) | |
360 | { | |
361 | struct vio_dev *viod = to_vio_dev(dev); | |
362 | struct hvcs_struct *hvcsd = from_vio_dev(viod); | |
363 | unsigned long flags; | |
364 | int retval; | |
365 | ||
366 | spin_lock_irqsave(&hvcsd->lock, flags); | |
367 | retval = sprintf(buf, "%X\n", hvcsd->p_unit_address); | |
368 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
369 | return retval; | |
370 | } | |
371 | static DEVICE_ATTR(partner_vtys, S_IRUGO, hvcs_partner_vtys_show, NULL); | |
372 | ||
373 | static ssize_t hvcs_partner_clcs_show(struct device *dev, struct device_attribute *attr, char *buf) | |
374 | { | |
375 | struct vio_dev *viod = to_vio_dev(dev); | |
376 | struct hvcs_struct *hvcsd = from_vio_dev(viod); | |
377 | unsigned long flags; | |
378 | int retval; | |
379 | ||
380 | spin_lock_irqsave(&hvcsd->lock, flags); | |
381 | retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]); | |
382 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
383 | return retval; | |
384 | } | |
385 | static DEVICE_ATTR(partner_clcs, S_IRUGO, hvcs_partner_clcs_show, NULL); | |
386 | ||
387 | static ssize_t hvcs_current_vty_store(struct device *dev, struct device_attribute *attr, const char * buf, | |
388 | size_t count) | |
389 | { | |
390 | /* | |
391 | * Don't need this feature at the present time because firmware doesn't | |
392 | * yet support multiple partners. | |
393 | */ | |
394 | printk(KERN_INFO "HVCS: Denied current_vty change: -EPERM.\n"); | |
395 | return -EPERM; | |
396 | } | |
397 | ||
398 | static ssize_t hvcs_current_vty_show(struct device *dev, struct device_attribute *attr, char *buf) | |
399 | { | |
400 | struct vio_dev *viod = to_vio_dev(dev); | |
401 | struct hvcs_struct *hvcsd = from_vio_dev(viod); | |
402 | unsigned long flags; | |
403 | int retval; | |
404 | ||
405 | spin_lock_irqsave(&hvcsd->lock, flags); | |
406 | retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]); | |
407 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
408 | return retval; | |
409 | } | |
410 | ||
411 | static DEVICE_ATTR(current_vty, | |
412 | S_IRUGO | S_IWUSR, hvcs_current_vty_show, hvcs_current_vty_store); | |
413 | ||
414 | static ssize_t hvcs_vterm_state_store(struct device *dev, struct device_attribute *attr, const char *buf, | |
415 | size_t count) | |
416 | { | |
417 | struct vio_dev *viod = to_vio_dev(dev); | |
418 | struct hvcs_struct *hvcsd = from_vio_dev(viod); | |
419 | unsigned long flags; | |
420 | ||
421 | /* writing a '0' to this sysfs entry will result in the disconnect. */ | |
422 | if (simple_strtol(buf, NULL, 0) != 0) | |
423 | return -EINVAL; | |
424 | ||
425 | spin_lock_irqsave(&hvcsd->lock, flags); | |
426 | ||
427 | if (hvcsd->open_count > 0) { | |
428 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
429 | printk(KERN_INFO "HVCS: vterm state unchanged. " | |
430 | "The hvcs device node is still in use.\n"); | |
431 | return -EPERM; | |
432 | } | |
433 | ||
434 | if (hvcsd->connected == 0) { | |
435 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
436 | printk(KERN_INFO "HVCS: vterm state unchanged. The" | |
437 | " vty-server is not connected to a vty.\n"); | |
438 | return -EPERM; | |
439 | } | |
440 | ||
441 | hvcs_partner_free(hvcsd); | |
442 | printk(KERN_INFO "HVCS: Closed vty-server@%X and" | |
443 | " partner vty@%X:%d connection.\n", | |
444 | hvcsd->vdev->unit_address, | |
445 | hvcsd->p_unit_address, | |
446 | (uint32_t)hvcsd->p_partition_ID); | |
447 | ||
448 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
449 | return count; | |
450 | } | |
451 | ||
452 | static ssize_t hvcs_vterm_state_show(struct device *dev, struct device_attribute *attr, char *buf) | |
453 | { | |
454 | struct vio_dev *viod = to_vio_dev(dev); | |
455 | struct hvcs_struct *hvcsd = from_vio_dev(viod); | |
456 | unsigned long flags; | |
457 | int retval; | |
458 | ||
459 | spin_lock_irqsave(&hvcsd->lock, flags); | |
460 | retval = sprintf(buf, "%d\n", hvcsd->connected); | |
461 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
462 | return retval; | |
463 | } | |
464 | static DEVICE_ATTR(vterm_state, S_IRUGO | S_IWUSR, | |
465 | hvcs_vterm_state_show, hvcs_vterm_state_store); | |
466 | ||
467 | static ssize_t hvcs_index_show(struct device *dev, struct device_attribute *attr, char *buf) | |
468 | { | |
469 | struct vio_dev *viod = to_vio_dev(dev); | |
470 | struct hvcs_struct *hvcsd = from_vio_dev(viod); | |
471 | unsigned long flags; | |
472 | int retval; | |
473 | ||
474 | spin_lock_irqsave(&hvcsd->lock, flags); | |
475 | retval = sprintf(buf, "%d\n", hvcsd->index); | |
476 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
477 | return retval; | |
478 | } | |
479 | ||
480 | static DEVICE_ATTR(index, S_IRUGO, hvcs_index_show, NULL); | |
481 | ||
482 | static struct attribute *hvcs_attrs[] = { | |
483 | &dev_attr_partner_vtys.attr, | |
484 | &dev_attr_partner_clcs.attr, | |
485 | &dev_attr_current_vty.attr, | |
486 | &dev_attr_vterm_state.attr, | |
487 | &dev_attr_index.attr, | |
488 | NULL, | |
489 | }; | |
490 | ||
491 | static struct attribute_group hvcs_attr_group = { | |
492 | .attrs = hvcs_attrs, | |
493 | }; | |
494 | ||
495 | static ssize_t hvcs_rescan_show(struct device_driver *ddp, char *buf) | |
496 | { | |
497 | /* A 1 means it is updating, a 0 means it is done updating */ | |
498 | return snprintf(buf, PAGE_SIZE, "%d\n", hvcs_rescan_status); | |
499 | } | |
500 | ||
501 | static ssize_t hvcs_rescan_store(struct device_driver *ddp, const char * buf, | |
502 | size_t count) | |
503 | { | |
504 | if ((simple_strtol(buf, NULL, 0) != 1) | |
505 | && (hvcs_rescan_status != 0)) | |
506 | return -EINVAL; | |
507 | ||
508 | hvcs_rescan_status = 1; | |
509 | printk(KERN_INFO "HVCS: rescanning partner info for all" | |
510 | " vty-servers.\n"); | |
511 | hvcs_rescan_devices_list(); | |
512 | hvcs_rescan_status = 0; | |
513 | return count; | |
514 | } | |
515 | ||
516 | static DRIVER_ATTR(rescan, | |
517 | S_IRUGO | S_IWUSR, hvcs_rescan_show, hvcs_rescan_store); | |
518 | ||
1da177e4 LT |
519 | static void hvcs_kick(void) |
520 | { | |
521 | hvcs_kicked = 1; | |
522 | wmb(); | |
523 | wake_up_process(hvcs_task); | |
524 | } | |
525 | ||
526 | static void hvcs_unthrottle(struct tty_struct *tty) | |
527 | { | |
528 | struct hvcs_struct *hvcsd = tty->driver_data; | |
529 | unsigned long flags; | |
530 | ||
531 | spin_lock_irqsave(&hvcsd->lock, flags); | |
532 | hvcsd->todo_mask |= HVCS_SCHED_READ; | |
533 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
534 | hvcs_kick(); | |
535 | } | |
536 | ||
537 | static void hvcs_throttle(struct tty_struct *tty) | |
538 | { | |
539 | struct hvcs_struct *hvcsd = tty->driver_data; | |
540 | unsigned long flags; | |
541 | ||
542 | spin_lock_irqsave(&hvcsd->lock, flags); | |
543 | vio_disable_interrupts(hvcsd->vdev); | |
544 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
545 | } | |
546 | ||
547 | /* | |
548 | * If the device is being removed we don't have to worry about this interrupt | |
549 | * handler taking any further interrupts because they are disabled which means | |
550 | * the hvcs_struct will always be valid in this handler. | |
551 | */ | |
7d12e780 | 552 | static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance) |
1da177e4 LT |
553 | { |
554 | struct hvcs_struct *hvcsd = dev_instance; | |
555 | ||
556 | spin_lock(&hvcsd->lock); | |
557 | vio_disable_interrupts(hvcsd->vdev); | |
558 | hvcsd->todo_mask |= HVCS_SCHED_READ; | |
559 | spin_unlock(&hvcsd->lock); | |
560 | hvcs_kick(); | |
561 | ||
562 | return IRQ_HANDLED; | |
563 | } | |
564 | ||
565 | /* This function must be called with the hvcsd->lock held */ | |
566 | static void hvcs_try_write(struct hvcs_struct *hvcsd) | |
567 | { | |
568 | uint32_t unit_address = hvcsd->vdev->unit_address; | |
569 | struct tty_struct *tty = hvcsd->tty; | |
570 | int sent; | |
571 | ||
572 | if (hvcsd->todo_mask & HVCS_TRY_WRITE) { | |
573 | /* won't send partial writes */ | |
574 | sent = hvc_put_chars(unit_address, | |
575 | &hvcsd->buffer[0], | |
576 | hvcsd->chars_in_buffer ); | |
577 | if (sent > 0) { | |
578 | hvcsd->chars_in_buffer = 0; | |
579 | /* wmb(); */ | |
580 | hvcsd->todo_mask &= ~(HVCS_TRY_WRITE); | |
581 | /* wmb(); */ | |
582 | ||
583 | /* | |
584 | * We are still obligated to deliver the data to the | |
585 | * hypervisor even if the tty has been closed because | |
586 | * we commited to delivering it. But don't try to wake | |
587 | * a non-existent tty. | |
588 | */ | |
589 | if (tty) { | |
590 | tty_wakeup(tty); | |
591 | } | |
592 | } | |
593 | } | |
594 | } | |
595 | ||
596 | static int hvcs_io(struct hvcs_struct *hvcsd) | |
597 | { | |
598 | uint32_t unit_address; | |
599 | struct tty_struct *tty; | |
600 | char buf[HVCS_BUFF_LEN] __ALIGNED__; | |
601 | unsigned long flags; | |
602 | int got = 0; | |
1da177e4 LT |
603 | |
604 | spin_lock_irqsave(&hvcsd->lock, flags); | |
605 | ||
606 | unit_address = hvcsd->vdev->unit_address; | |
607 | tty = hvcsd->tty; | |
608 | ||
609 | hvcs_try_write(hvcsd); | |
610 | ||
611 | if (!tty || test_bit(TTY_THROTTLED, &tty->flags)) { | |
612 | hvcsd->todo_mask &= ~(HVCS_READ_MASK); | |
613 | goto bail; | |
614 | } else if (!(hvcsd->todo_mask & (HVCS_READ_MASK))) | |
615 | goto bail; | |
616 | ||
617 | /* remove the read masks */ | |
618 | hvcsd->todo_mask &= ~(HVCS_READ_MASK); | |
619 | ||
33f0f88f | 620 | if (tty_buffer_request_room(tty, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) { |
1da177e4 LT |
621 | got = hvc_get_chars(unit_address, |
622 | &buf[0], | |
623 | HVCS_BUFF_LEN); | |
33f0f88f | 624 | tty_insert_flip_string(tty, buf, got); |
1da177e4 LT |
625 | } |
626 | ||
627 | /* Give the TTY time to process the data we just sent. */ | |
628 | if (got) | |
629 | hvcsd->todo_mask |= HVCS_QUICK_READ; | |
630 | ||
631 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
33f0f88f AC |
632 | /* This is synch because tty->low_latency == 1 */ |
633 | if(got) | |
1da177e4 | 634 | tty_flip_buffer_push(tty); |
1da177e4 LT |
635 | |
636 | if (!got) { | |
637 | /* Do this _after_ the flip_buffer_push */ | |
638 | spin_lock_irqsave(&hvcsd->lock, flags); | |
639 | vio_enable_interrupts(hvcsd->vdev); | |
640 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
641 | } | |
642 | ||
643 | return hvcsd->todo_mask; | |
644 | ||
645 | bail: | |
646 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
647 | return hvcsd->todo_mask; | |
648 | } | |
649 | ||
650 | static int khvcsd(void *unused) | |
651 | { | |
652 | struct hvcs_struct *hvcsd; | |
653 | int hvcs_todo_mask; | |
654 | ||
655 | __set_current_state(TASK_RUNNING); | |
656 | ||
657 | do { | |
658 | hvcs_todo_mask = 0; | |
659 | hvcs_kicked = 0; | |
660 | wmb(); | |
661 | ||
662 | spin_lock(&hvcs_structs_lock); | |
663 | list_for_each_entry(hvcsd, &hvcs_structs, next) { | |
664 | hvcs_todo_mask |= hvcs_io(hvcsd); | |
665 | } | |
666 | spin_unlock(&hvcs_structs_lock); | |
667 | ||
668 | /* | |
669 | * If any of the hvcs adapters want to try a write or quick read | |
670 | * don't schedule(), yield a smidgen then execute the hvcs_io | |
671 | * thread again for those that want the write. | |
672 | */ | |
673 | if (hvcs_todo_mask & (HVCS_TRY_WRITE | HVCS_QUICK_READ)) { | |
674 | yield(); | |
675 | continue; | |
676 | } | |
677 | ||
678 | set_current_state(TASK_INTERRUPTIBLE); | |
679 | if (!hvcs_kicked) | |
680 | schedule(); | |
681 | __set_current_state(TASK_RUNNING); | |
682 | } while (!kthread_should_stop()); | |
683 | ||
684 | return 0; | |
685 | } | |
686 | ||
687 | static struct vio_device_id hvcs_driver_table[] __devinitdata= { | |
688 | {"serial-server", "hvterm2"}, | |
fb120da6 | 689 | { "", "" } |
1da177e4 LT |
690 | }; |
691 | MODULE_DEVICE_TABLE(vio, hvcs_driver_table); | |
692 | ||
693 | static void hvcs_return_index(int index) | |
694 | { | |
695 | /* Paranoia check */ | |
696 | if (!hvcs_index_list) | |
697 | return; | |
698 | if (index < 0 || index >= hvcs_index_count) | |
699 | return; | |
700 | if (hvcs_index_list[index] == -1) | |
701 | return; | |
702 | else | |
703 | hvcs_index_list[index] = -1; | |
704 | } | |
705 | ||
706 | /* callback when the kboject ref count reaches zero */ | |
707 | static void destroy_hvcs_struct(struct kobject *kobj) | |
708 | { | |
709 | struct hvcs_struct *hvcsd = from_kobj(kobj); | |
710 | struct vio_dev *vdev; | |
711 | unsigned long flags; | |
712 | ||
713 | spin_lock(&hvcs_structs_lock); | |
714 | spin_lock_irqsave(&hvcsd->lock, flags); | |
715 | ||
716 | /* the list_del poisons the pointers */ | |
717 | list_del(&(hvcsd->next)); | |
718 | ||
719 | if (hvcsd->connected == 1) { | |
720 | hvcs_partner_free(hvcsd); | |
721 | printk(KERN_INFO "HVCS: Closed vty-server@%X and" | |
722 | " partner vty@%X:%d connection.\n", | |
723 | hvcsd->vdev->unit_address, | |
724 | hvcsd->p_unit_address, | |
725 | (uint32_t)hvcsd->p_partition_ID); | |
726 | } | |
727 | printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n", | |
728 | hvcsd->vdev->unit_address); | |
729 | ||
730 | vdev = hvcsd->vdev; | |
731 | hvcsd->vdev = NULL; | |
732 | ||
733 | hvcsd->p_unit_address = 0; | |
734 | hvcsd->p_partition_ID = 0; | |
735 | hvcs_return_index(hvcsd->index); | |
736 | memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1); | |
737 | ||
738 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
739 | spin_unlock(&hvcs_structs_lock); | |
740 | ||
c15bb296 | 741 | sysfs_remove_group(&vdev->dev.kobj, &hvcs_attr_group); |
1da177e4 LT |
742 | |
743 | kfree(hvcsd); | |
744 | } | |
745 | ||
746 | static struct kobj_type hvcs_kobj_type = { | |
747 | .release = destroy_hvcs_struct, | |
748 | }; | |
749 | ||
750 | static int hvcs_get_index(void) | |
751 | { | |
752 | int i; | |
753 | /* Paranoia check */ | |
754 | if (!hvcs_index_list) { | |
755 | printk(KERN_ERR "HVCS: hvcs_index_list NOT valid!.\n"); | |
756 | return -EFAULT; | |
757 | } | |
758 | /* Find the numerically lowest first free index. */ | |
759 | for(i = 0; i < hvcs_index_count; i++) { | |
760 | if (hvcs_index_list[i] == -1) { | |
761 | hvcs_index_list[i] = 0; | |
762 | return i; | |
763 | } | |
764 | } | |
765 | return -1; | |
766 | } | |
767 | ||
768 | static int __devinit hvcs_probe( | |
769 | struct vio_dev *dev, | |
770 | const struct vio_device_id *id) | |
771 | { | |
772 | struct hvcs_struct *hvcsd; | |
773 | int index; | |
c15bb296 | 774 | int retval; |
1da177e4 LT |
775 | |
776 | if (!dev || !id) { | |
777 | printk(KERN_ERR "HVCS: probed with invalid parameter.\n"); | |
778 | return -EPERM; | |
779 | } | |
780 | ||
781 | /* early to avoid cleanup on failure */ | |
782 | index = hvcs_get_index(); | |
783 | if (index < 0) { | |
784 | return -EFAULT; | |
785 | } | |
786 | ||
787 | hvcsd = kmalloc(sizeof(*hvcsd), GFP_KERNEL); | |
788 | if (!hvcsd) | |
789 | return -ENODEV; | |
790 | ||
791 | /* hvcsd->tty is zeroed out with the memset */ | |
792 | memset(hvcsd, 0x00, sizeof(*hvcsd)); | |
793 | ||
794 | spin_lock_init(&hvcsd->lock); | |
795 | /* Automatically incs the refcount the first time */ | |
796 | kobject_init(&hvcsd->kobj); | |
797 | /* Set up the callback for terminating the hvcs_struct's life */ | |
798 | hvcsd->kobj.ktype = &hvcs_kobj_type; | |
799 | ||
800 | hvcsd->vdev = dev; | |
801 | dev->dev.driver_data = hvcsd; | |
802 | ||
803 | hvcsd->index = index; | |
804 | ||
805 | /* hvcsd->index = ++hvcs_struct_count; */ | |
806 | hvcsd->chars_in_buffer = 0; | |
807 | hvcsd->todo_mask = 0; | |
808 | hvcsd->connected = 0; | |
809 | ||
810 | /* | |
811 | * This will populate the hvcs_struct's partner info fields for the | |
812 | * first time. | |
813 | */ | |
814 | if (hvcs_get_pi(hvcsd)) { | |
815 | printk(KERN_ERR "HVCS: Failed to fetch partner" | |
816 | " info for vty-server@%X on device probe.\n", | |
817 | hvcsd->vdev->unit_address); | |
818 | } | |
819 | ||
820 | /* | |
821 | * If a user app opens a tty that corresponds to this vty-server before | |
822 | * the hvcs_struct has been added to the devices list then the user app | |
823 | * will get -ENODEV. | |
824 | */ | |
1da177e4 | 825 | spin_lock(&hvcs_structs_lock); |
1da177e4 | 826 | list_add_tail(&(hvcsd->next), &hvcs_structs); |
1da177e4 LT |
827 | spin_unlock(&hvcs_structs_lock); |
828 | ||
c15bb296 LV |
829 | retval = sysfs_create_group(&dev->dev.kobj, &hvcs_attr_group); |
830 | if (retval) { | |
831 | printk(KERN_ERR "HVCS: Can't create sysfs attrs for vty-server@%X\n", | |
832 | hvcsd->vdev->unit_address); | |
833 | return retval; | |
834 | } | |
1da177e4 LT |
835 | |
836 | printk(KERN_INFO "HVCS: vty-server@%X added to the vio bus.\n", dev->unit_address); | |
837 | ||
838 | /* | |
839 | * DON'T enable interrupts here because there is no user to receive the | |
840 | * data. | |
841 | */ | |
842 | return 0; | |
843 | } | |
844 | ||
845 | static int __devexit hvcs_remove(struct vio_dev *dev) | |
846 | { | |
847 | struct hvcs_struct *hvcsd = dev->dev.driver_data; | |
848 | unsigned long flags; | |
849 | struct kobject *kobjp; | |
850 | struct tty_struct *tty; | |
851 | ||
852 | if (!hvcsd) | |
853 | return -ENODEV; | |
854 | ||
855 | /* By this time the vty-server won't be getting any more interrups */ | |
856 | ||
857 | spin_lock_irqsave(&hvcsd->lock, flags); | |
858 | ||
859 | tty = hvcsd->tty; | |
860 | ||
861 | kobjp = &hvcsd->kobj; | |
862 | ||
863 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
864 | ||
865 | /* | |
866 | * Let the last holder of this object cause it to be removed, which | |
867 | * would probably be tty_hangup below. | |
868 | */ | |
869 | kobject_put (kobjp); | |
870 | ||
871 | /* | |
872 | * The hangup is a scheduled function which will auto chain call | |
873 | * hvcs_hangup. The tty should always be valid at this time unless a | |
874 | * simultaneous tty close already cleaned up the hvcs_struct. | |
875 | */ | |
876 | if (tty) | |
877 | tty_hangup(tty); | |
878 | ||
879 | printk(KERN_INFO "HVCS: vty-server@%X removed from the" | |
880 | " vio bus.\n", dev->unit_address); | |
881 | return 0; | |
882 | }; | |
883 | ||
884 | static struct vio_driver hvcs_vio_driver = { | |
1da177e4 LT |
885 | .id_table = hvcs_driver_table, |
886 | .probe = hvcs_probe, | |
887 | .remove = hvcs_remove, | |
6fdf5392 SR |
888 | .driver = { |
889 | .name = hvcs_driver_name, | |
915124d8 | 890 | .owner = THIS_MODULE, |
6fdf5392 | 891 | } |
1da177e4 LT |
892 | }; |
893 | ||
894 | /* Only called from hvcs_get_pi please */ | |
895 | static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd) | |
896 | { | |
897 | int clclength; | |
898 | ||
899 | hvcsd->p_unit_address = pi->unit_address; | |
900 | hvcsd->p_partition_ID = pi->partition_ID; | |
901 | clclength = strlen(&pi->location_code[0]); | |
902 | if (clclength > HVCS_CLC_LENGTH) | |
903 | clclength = HVCS_CLC_LENGTH; | |
904 | ||
905 | /* copy the null-term char too */ | |
906 | strncpy(&hvcsd->p_location_code[0], | |
907 | &pi->location_code[0], clclength + 1); | |
908 | } | |
909 | ||
910 | /* | |
911 | * Traverse the list and add the partner info that is found to the hvcs_struct | |
912 | * struct entry. NOTE: At this time I know that partner info will return a | |
913 | * single entry but in the future there may be multiple partner info entries per | |
914 | * vty-server and you'll want to zero out that list and reset it. If for some | |
915 | * reason you have an old version of this driver but there IS more than one | |
916 | * partner info then hvcsd->p_* will hold the last partner info data from the | |
917 | * firmware query. A good way to update this code would be to replace the three | |
918 | * partner info fields in hvcs_struct with a list of hvcs_partner_info | |
919 | * instances. | |
920 | * | |
921 | * This function must be called with the hvcsd->lock held. | |
922 | */ | |
923 | static int hvcs_get_pi(struct hvcs_struct *hvcsd) | |
924 | { | |
925 | struct hvcs_partner_info *pi; | |
926 | uint32_t unit_address = hvcsd->vdev->unit_address; | |
927 | struct list_head head; | |
928 | int retval; | |
929 | ||
930 | spin_lock(&hvcs_pi_lock); | |
931 | if (!hvcs_pi_buff) { | |
932 | spin_unlock(&hvcs_pi_lock); | |
933 | return -EFAULT; | |
934 | } | |
935 | retval = hvcs_get_partner_info(unit_address, &head, hvcs_pi_buff); | |
936 | spin_unlock(&hvcs_pi_lock); | |
937 | if (retval) { | |
938 | printk(KERN_ERR "HVCS: Failed to fetch partner" | |
939 | " info for vty-server@%x.\n", unit_address); | |
940 | return retval; | |
941 | } | |
942 | ||
943 | /* nixes the values if the partner vty went away */ | |
944 | hvcsd->p_unit_address = 0; | |
945 | hvcsd->p_partition_ID = 0; | |
946 | ||
947 | list_for_each_entry(pi, &head, node) | |
948 | hvcs_set_pi(pi, hvcsd); | |
949 | ||
950 | hvcs_free_partner_info(&head); | |
951 | return 0; | |
952 | } | |
953 | ||
954 | /* | |
955 | * This function is executed by the driver "rescan" sysfs entry. It shouldn't | |
956 | * be executed elsewhere, in order to prevent deadlock issues. | |
957 | */ | |
958 | static int hvcs_rescan_devices_list(void) | |
959 | { | |
960 | struct hvcs_struct *hvcsd; | |
961 | unsigned long flags; | |
962 | ||
963 | spin_lock(&hvcs_structs_lock); | |
964 | ||
965 | list_for_each_entry(hvcsd, &hvcs_structs, next) { | |
966 | spin_lock_irqsave(&hvcsd->lock, flags); | |
967 | hvcs_get_pi(hvcsd); | |
968 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
969 | } | |
970 | ||
971 | spin_unlock(&hvcs_structs_lock); | |
972 | ||
973 | return 0; | |
974 | } | |
975 | ||
976 | /* | |
977 | * Farm this off into its own function because it could be more complex once | |
978 | * multiple partners support is added. This function should be called with | |
979 | * the hvcsd->lock held. | |
980 | */ | |
981 | static int hvcs_has_pi(struct hvcs_struct *hvcsd) | |
982 | { | |
983 | if ((!hvcsd->p_unit_address) || (!hvcsd->p_partition_ID)) | |
984 | return 0; | |
985 | return 1; | |
986 | } | |
987 | ||
988 | /* | |
989 | * NOTE: It is possible that the super admin removed a partner vty and then | |
990 | * added a different vty as the new partner. | |
991 | * | |
992 | * This function must be called with the hvcsd->lock held. | |
993 | */ | |
994 | static int hvcs_partner_connect(struct hvcs_struct *hvcsd) | |
995 | { | |
996 | int retval; | |
997 | unsigned int unit_address = hvcsd->vdev->unit_address; | |
998 | ||
999 | /* | |
1000 | * If there wasn't any pi when the device was added it doesn't meant | |
1001 | * there isn't any now. This driver isn't notified when a new partner | |
1002 | * vty is added to a vty-server so we discover changes on our own. | |
1003 | * Please see comments in hvcs_register_connection() for justification | |
1004 | * of this bizarre code. | |
1005 | */ | |
1006 | retval = hvcs_register_connection(unit_address, | |
1007 | hvcsd->p_partition_ID, | |
1008 | hvcsd->p_unit_address); | |
1009 | if (!retval) { | |
1010 | hvcsd->connected = 1; | |
1011 | return 0; | |
1012 | } else if (retval != -EINVAL) | |
1013 | return retval; | |
1014 | ||
1015 | /* | |
1016 | * As per the spec re-get the pi and try again if -EINVAL after the | |
1017 | * first connection attempt. | |
1018 | */ | |
1019 | if (hvcs_get_pi(hvcsd)) | |
1020 | return -ENOMEM; | |
1021 | ||
1022 | if (!hvcs_has_pi(hvcsd)) | |
1023 | return -ENODEV; | |
1024 | ||
1025 | retval = hvcs_register_connection(unit_address, | |
1026 | hvcsd->p_partition_ID, | |
1027 | hvcsd->p_unit_address); | |
1028 | if (retval != -EINVAL) { | |
1029 | hvcsd->connected = 1; | |
1030 | return retval; | |
1031 | } | |
1032 | ||
1033 | /* | |
1034 | * EBUSY is the most likely scenario though the vty could have been | |
1035 | * removed or there really could be an hcall error due to the parameter | |
1036 | * data but thanks to ambiguous firmware return codes we can't really | |
1037 | * tell. | |
1038 | */ | |
1039 | printk(KERN_INFO "HVCS: vty-server or partner" | |
1040 | " vty is busy. Try again later.\n"); | |
1041 | return -EBUSY; | |
1042 | } | |
1043 | ||
1044 | /* This function must be called with the hvcsd->lock held */ | |
1045 | static void hvcs_partner_free(struct hvcs_struct *hvcsd) | |
1046 | { | |
1047 | int retval; | |
1048 | do { | |
1049 | retval = hvcs_free_connection(hvcsd->vdev->unit_address); | |
1050 | } while (retval == -EBUSY); | |
1051 | hvcsd->connected = 0; | |
1052 | } | |
1053 | ||
1054 | /* This helper function must be called WITHOUT the hvcsd->lock held */ | |
1055 | static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address, | |
1056 | unsigned int irq, struct vio_dev *vdev) | |
1057 | { | |
1058 | unsigned long flags; | |
1059 | int rc; | |
1060 | ||
1061 | /* | |
1062 | * It is possible that the vty-server was removed between the time that | |
1063 | * the conn was registered and now. | |
1064 | */ | |
1065 | if (!(rc = request_irq(irq, &hvcs_handle_interrupt, | |
0f2ed4c6 | 1066 | IRQF_DISABLED, "ibmhvcs", hvcsd))) { |
1da177e4 LT |
1067 | /* |
1068 | * It is possible the vty-server was removed after the irq was | |
1069 | * requested but before we have time to enable interrupts. | |
1070 | */ | |
706c8c93 | 1071 | if (vio_enable_interrupts(vdev) == H_SUCCESS) |
1da177e4 LT |
1072 | return 0; |
1073 | else { | |
1074 | printk(KERN_ERR "HVCS: int enable failed for" | |
1075 | " vty-server@%X.\n", unit_address); | |
1076 | free_irq(irq, hvcsd); | |
1077 | } | |
1078 | } else | |
1079 | printk(KERN_ERR "HVCS: irq req failed for" | |
1080 | " vty-server@%X.\n", unit_address); | |
1081 | ||
1082 | spin_lock_irqsave(&hvcsd->lock, flags); | |
1083 | hvcs_partner_free(hvcsd); | |
1084 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1085 | ||
1086 | return rc; | |
1087 | ||
1088 | } | |
1089 | ||
1090 | /* | |
1091 | * This always increments the kobject ref count if the call is successful. | |
1092 | * Please remember to dec when you are done with the instance. | |
1093 | * | |
1094 | * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when | |
1095 | * calling this function or you will get deadlock. | |
1096 | */ | |
1097 | struct hvcs_struct *hvcs_get_by_index(int index) | |
1098 | { | |
1099 | struct hvcs_struct *hvcsd = NULL; | |
1100 | unsigned long flags; | |
1101 | ||
1102 | spin_lock(&hvcs_structs_lock); | |
1103 | /* We can immediately discard OOB requests */ | |
1104 | if (index >= 0 && index < HVCS_MAX_SERVER_ADAPTERS) { | |
1105 | list_for_each_entry(hvcsd, &hvcs_structs, next) { | |
1106 | spin_lock_irqsave(&hvcsd->lock, flags); | |
1107 | if (hvcsd->index == index) { | |
1108 | kobject_get(&hvcsd->kobj); | |
1109 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1110 | spin_unlock(&hvcs_structs_lock); | |
1111 | return hvcsd; | |
1112 | } | |
1113 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1114 | } | |
1115 | hvcsd = NULL; | |
1116 | } | |
1117 | ||
1118 | spin_unlock(&hvcs_structs_lock); | |
1119 | return hvcsd; | |
1120 | } | |
1121 | ||
1122 | /* | |
1123 | * This is invoked via the tty_open interface when a user app connects to the | |
1124 | * /dev node. | |
1125 | */ | |
1126 | static int hvcs_open(struct tty_struct *tty, struct file *filp) | |
1127 | { | |
1128 | struct hvcs_struct *hvcsd; | |
1129 | int rc, retval = 0; | |
1130 | unsigned long flags; | |
1131 | unsigned int irq; | |
1132 | struct vio_dev *vdev; | |
1133 | unsigned long unit_address; | |
1134 | struct kobject *kobjp; | |
1135 | ||
1136 | if (tty->driver_data) | |
1137 | goto fast_open; | |
1138 | ||
1139 | /* | |
1140 | * Is there a vty-server that shares the same index? | |
1141 | * This function increments the kobject index. | |
1142 | */ | |
1143 | if (!(hvcsd = hvcs_get_by_index(tty->index))) { | |
1144 | printk(KERN_WARNING "HVCS: open failed, no device associated" | |
1145 | " with tty->index %d.\n", tty->index); | |
1146 | return -ENODEV; | |
1147 | } | |
1148 | ||
1149 | spin_lock_irqsave(&hvcsd->lock, flags); | |
1150 | ||
1151 | if (hvcsd->connected == 0) | |
1152 | if ((retval = hvcs_partner_connect(hvcsd))) | |
1153 | goto error_release; | |
1154 | ||
1155 | hvcsd->open_count = 1; | |
1156 | hvcsd->tty = tty; | |
1157 | tty->driver_data = hvcsd; | |
1158 | ||
1159 | /* | |
1160 | * Set this driver to low latency so that we actually have a chance at | |
1161 | * catching a throttled TTY after we flip_buffer_push. Otherwise the | |
1162 | * flush_to_async may not execute until after the kernel_thread has | |
1163 | * yielded and resumed the next flip_buffer_push resulting in data | |
1164 | * loss. | |
1165 | */ | |
1166 | tty->low_latency = 1; | |
1167 | ||
1168 | memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); | |
1169 | ||
1170 | /* | |
1171 | * Save these in the spinlock for the enable operations that need them | |
1172 | * outside of the spinlock. | |
1173 | */ | |
1174 | irq = hvcsd->vdev->irq; | |
1175 | vdev = hvcsd->vdev; | |
1176 | unit_address = hvcsd->vdev->unit_address; | |
1177 | ||
1178 | hvcsd->todo_mask |= HVCS_SCHED_READ; | |
1179 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1180 | ||
1181 | /* | |
1182 | * This must be done outside of the spinlock because it requests irqs | |
1183 | * and will grab the spinlock and free the connection if it fails. | |
1184 | */ | |
1185 | if (((rc = hvcs_enable_device(hvcsd, unit_address, irq, vdev)))) { | |
1186 | kobject_put(&hvcsd->kobj); | |
1187 | printk(KERN_WARNING "HVCS: enable device failed.\n"); | |
1188 | return rc; | |
1189 | } | |
1190 | ||
1191 | goto open_success; | |
1192 | ||
1193 | fast_open: | |
1194 | hvcsd = tty->driver_data; | |
1195 | ||
1196 | spin_lock_irqsave(&hvcsd->lock, flags); | |
1197 | if (!kobject_get(&hvcsd->kobj)) { | |
1198 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1199 | printk(KERN_ERR "HVCS: Kobject of open" | |
1200 | " hvcs doesn't exist.\n"); | |
1201 | return -EFAULT; /* Is this the right return value? */ | |
1202 | } | |
1203 | ||
1204 | hvcsd->open_count++; | |
1205 | ||
1206 | hvcsd->todo_mask |= HVCS_SCHED_READ; | |
1207 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1208 | open_success: | |
1209 | hvcs_kick(); | |
1210 | ||
1211 | printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n", | |
1212 | hvcsd->vdev->unit_address ); | |
1213 | ||
1214 | return 0; | |
1215 | ||
1216 | error_release: | |
1217 | kobjp = &hvcsd->kobj; | |
1218 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1219 | kobject_put(&hvcsd->kobj); | |
1220 | ||
1221 | printk(KERN_WARNING "HVCS: partner connect failed.\n"); | |
1222 | return retval; | |
1223 | } | |
1224 | ||
1225 | static void hvcs_close(struct tty_struct *tty, struct file *filp) | |
1226 | { | |
1227 | struct hvcs_struct *hvcsd; | |
1228 | unsigned long flags; | |
1229 | struct kobject *kobjp; | |
1230 | int irq = NO_IRQ; | |
1231 | ||
1232 | /* | |
1233 | * Is someone trying to close the file associated with this device after | |
1234 | * we have hung up? If so tty->driver_data wouldn't be valid. | |
1235 | */ | |
1236 | if (tty_hung_up_p(filp)) | |
1237 | return; | |
1238 | ||
1239 | /* | |
1240 | * No driver_data means that this close was probably issued after a | |
1241 | * failed hvcs_open by the tty layer's release_dev() api and we can just | |
1242 | * exit cleanly. | |
1243 | */ | |
1244 | if (!tty->driver_data) | |
1245 | return; | |
1246 | ||
1247 | hvcsd = tty->driver_data; | |
1248 | ||
1249 | spin_lock_irqsave(&hvcsd->lock, flags); | |
1250 | kobjp = &hvcsd->kobj; | |
1251 | if (--hvcsd->open_count == 0) { | |
1252 | ||
1253 | vio_disable_interrupts(hvcsd->vdev); | |
1254 | ||
1255 | /* | |
1256 | * NULL this early so that the kernel_thread doesn't try to | |
1257 | * execute any operations on the TTY even though it is obligated | |
1258 | * to deliver any pending I/O to the hypervisor. | |
1259 | */ | |
1260 | hvcsd->tty = NULL; | |
1261 | ||
1262 | irq = hvcsd->vdev->irq; | |
1263 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1264 | ||
1265 | tty_wait_until_sent(tty, HVCS_CLOSE_WAIT); | |
1266 | ||
1267 | /* | |
1268 | * This line is important because it tells hvcs_open that this | |
1269 | * device needs to be re-configured the next time hvcs_open is | |
1270 | * called. | |
1271 | */ | |
1272 | tty->driver_data = NULL; | |
1273 | ||
1274 | free_irq(irq, hvcsd); | |
1275 | kobject_put(kobjp); | |
1276 | return; | |
1277 | } else if (hvcsd->open_count < 0) { | |
1278 | printk(KERN_ERR "HVCS: vty-server@%X open_count: %d" | |
1279 | " is missmanaged.\n", | |
1280 | hvcsd->vdev->unit_address, hvcsd->open_count); | |
1281 | } | |
1282 | ||
1283 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1284 | kobject_put(kobjp); | |
1285 | } | |
1286 | ||
1287 | static void hvcs_hangup(struct tty_struct * tty) | |
1288 | { | |
1289 | struct hvcs_struct *hvcsd = tty->driver_data; | |
1290 | unsigned long flags; | |
1291 | int temp_open_count; | |
1292 | struct kobject *kobjp; | |
1293 | int irq = NO_IRQ; | |
1294 | ||
1295 | spin_lock_irqsave(&hvcsd->lock, flags); | |
1296 | /* Preserve this so that we know how many kobject refs to put */ | |
1297 | temp_open_count = hvcsd->open_count; | |
1298 | ||
1299 | /* | |
1300 | * Don't kobject put inside the spinlock because the destruction | |
1301 | * callback may use the spinlock and it may get called before the | |
1302 | * spinlock has been released. Get a pointer to the kobject and | |
1303 | * kobject_put on that after releasing the spinlock. | |
1304 | */ | |
1305 | kobjp = &hvcsd->kobj; | |
1306 | ||
1307 | vio_disable_interrupts(hvcsd->vdev); | |
1308 | ||
1309 | hvcsd->todo_mask = 0; | |
1310 | ||
1311 | /* I don't think the tty needs the hvcs_struct pointer after a hangup */ | |
1312 | hvcsd->tty->driver_data = NULL; | |
1313 | hvcsd->tty = NULL; | |
1314 | ||
1315 | hvcsd->open_count = 0; | |
1316 | ||
1317 | /* This will drop any buffered data on the floor which is OK in a hangup | |
1318 | * scenario. */ | |
1319 | memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); | |
1320 | hvcsd->chars_in_buffer = 0; | |
1321 | ||
1322 | irq = hvcsd->vdev->irq; | |
1323 | ||
1324 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1325 | ||
1326 | free_irq(irq, hvcsd); | |
1327 | ||
1328 | /* | |
1329 | * We need to kobject_put() for every open_count we have since the | |
1330 | * tty_hangup() function doesn't invoke a close per open connection on a | |
1331 | * non-console device. | |
1332 | */ | |
1333 | while(temp_open_count) { | |
1334 | --temp_open_count; | |
1335 | /* | |
1336 | * The final put will trigger destruction of the hvcs_struct. | |
1337 | * NOTE: If this hangup was signaled from user space then the | |
1338 | * final put will never happen. | |
1339 | */ | |
1340 | kobject_put(kobjp); | |
1341 | } | |
1342 | } | |
1343 | ||
1344 | /* | |
1345 | * NOTE: This is almost always from_user since user level apps interact with the | |
1346 | * /dev nodes. I'm trusting that if hvcs_write gets called and interrupted by | |
1347 | * hvcs_remove (which removes the target device and executes tty_hangup()) that | |
1348 | * tty_hangup will allow hvcs_write time to complete execution before it | |
1349 | * terminates our device. | |
1350 | */ | |
1351 | static int hvcs_write(struct tty_struct *tty, | |
1352 | const unsigned char *buf, int count) | |
1353 | { | |
1354 | struct hvcs_struct *hvcsd = tty->driver_data; | |
1355 | unsigned int unit_address; | |
1356 | const unsigned char *charbuf; | |
1357 | unsigned long flags; | |
1358 | int total_sent = 0; | |
1359 | int tosend = 0; | |
1360 | int result = 0; | |
1361 | ||
1362 | /* | |
1363 | * If they don't check the return code off of their open they may | |
1364 | * attempt this even if there is no connected device. | |
1365 | */ | |
1366 | if (!hvcsd) | |
1367 | return -ENODEV; | |
1368 | ||
1369 | /* Reasonable size to prevent user level flooding */ | |
1370 | if (count > HVCS_MAX_FROM_USER) { | |
1371 | printk(KERN_WARNING "HVCS write: count being truncated to" | |
1372 | " HVCS_MAX_FROM_USER.\n"); | |
1373 | count = HVCS_MAX_FROM_USER; | |
1374 | } | |
1375 | ||
1376 | charbuf = buf; | |
1377 | ||
1378 | spin_lock_irqsave(&hvcsd->lock, flags); | |
1379 | ||
1380 | /* | |
1381 | * Somehow an open succedded but the device was removed or the | |
1382 | * connection terminated between the vty-server and partner vty during | |
1383 | * the middle of a write operation? This is a crummy place to do this | |
1384 | * but we want to keep it all in the spinlock. | |
1385 | */ | |
1386 | if (hvcsd->open_count <= 0) { | |
1387 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1388 | return -ENODEV; | |
1389 | } | |
1390 | ||
1391 | unit_address = hvcsd->vdev->unit_address; | |
1392 | ||
1393 | while (count > 0) { | |
1394 | tosend = min(count, (HVCS_BUFF_LEN - hvcsd->chars_in_buffer)); | |
1395 | /* | |
1396 | * No more space, this probably means that the last call to | |
1397 | * hvcs_write() didn't succeed and the buffer was filled up. | |
1398 | */ | |
1399 | if (!tosend) | |
1400 | break; | |
1401 | ||
1402 | memcpy(&hvcsd->buffer[hvcsd->chars_in_buffer], | |
1403 | &charbuf[total_sent], | |
1404 | tosend); | |
1405 | ||
1406 | hvcsd->chars_in_buffer += tosend; | |
1407 | ||
1408 | result = 0; | |
1409 | ||
1410 | /* | |
1411 | * If this is true then we don't want to try writing to the | |
1412 | * hypervisor because that is the kernel_threads job now. We'll | |
1413 | * just add to the buffer. | |
1414 | */ | |
1415 | if (!(hvcsd->todo_mask & HVCS_TRY_WRITE)) | |
1416 | /* won't send partial writes */ | |
1417 | result = hvc_put_chars(unit_address, | |
1418 | &hvcsd->buffer[0], | |
1419 | hvcsd->chars_in_buffer); | |
1420 | ||
1421 | /* | |
1422 | * Since we know we have enough room in hvcsd->buffer for | |
1423 | * tosend we record that it was sent regardless of whether the | |
1424 | * hypervisor actually took it because we have it buffered. | |
1425 | */ | |
1426 | total_sent+=tosend; | |
1427 | count-=tosend; | |
1428 | if (result == 0) { | |
1429 | hvcsd->todo_mask |= HVCS_TRY_WRITE; | |
1430 | hvcs_kick(); | |
1431 | break; | |
1432 | } | |
1433 | ||
1434 | hvcsd->chars_in_buffer = 0; | |
1435 | /* | |
1436 | * Test after the chars_in_buffer reset otherwise this could | |
1437 | * deadlock our writes if hvc_put_chars fails. | |
1438 | */ | |
1439 | if (result < 0) | |
1440 | break; | |
1441 | } | |
1442 | ||
1443 | spin_unlock_irqrestore(&hvcsd->lock, flags); | |
1444 | ||
1445 | if (result == -1) | |
1446 | return -EIO; | |
1447 | else | |
1448 | return total_sent; | |
1449 | } | |
1450 | ||
1451 | /* | |
1452 | * This is really asking how much can we guarentee that we can send or that we | |
1453 | * absolutely WILL BUFFER if we can't send it. This driver MUST honor the | |
1454 | * return value, hence the reason for hvcs_struct buffering. | |
1455 | */ | |
1456 | static int hvcs_write_room(struct tty_struct *tty) | |
1457 | { | |
1458 | struct hvcs_struct *hvcsd = tty->driver_data; | |
1459 | ||
1460 | if (!hvcsd || hvcsd->open_count <= 0) | |
1461 | return 0; | |
1462 | ||
1463 | return HVCS_BUFF_LEN - hvcsd->chars_in_buffer; | |
1464 | } | |
1465 | ||
1466 | static int hvcs_chars_in_buffer(struct tty_struct *tty) | |
1467 | { | |
1468 | struct hvcs_struct *hvcsd = tty->driver_data; | |
1469 | ||
1470 | return hvcsd->chars_in_buffer; | |
1471 | } | |
1472 | ||
b68e31d0 | 1473 | static const struct tty_operations hvcs_ops = { |
1da177e4 LT |
1474 | .open = hvcs_open, |
1475 | .close = hvcs_close, | |
1476 | .hangup = hvcs_hangup, | |
1477 | .write = hvcs_write, | |
1478 | .write_room = hvcs_write_room, | |
1479 | .chars_in_buffer = hvcs_chars_in_buffer, | |
1480 | .unthrottle = hvcs_unthrottle, | |
1481 | .throttle = hvcs_throttle, | |
1482 | }; | |
1483 | ||
1484 | static int hvcs_alloc_index_list(int n) | |
1485 | { | |
1486 | int i; | |
8f760780 | 1487 | |
1da177e4 LT |
1488 | hvcs_index_list = kmalloc(n * sizeof(hvcs_index_count),GFP_KERNEL); |
1489 | if (!hvcs_index_list) | |
1490 | return -ENOMEM; | |
1491 | hvcs_index_count = n; | |
8f760780 | 1492 | for (i = 0; i < hvcs_index_count; i++) |
1da177e4 LT |
1493 | hvcs_index_list[i] = -1; |
1494 | return 0; | |
1495 | } | |
1496 | ||
1497 | static void hvcs_free_index_list(void) | |
1498 | { | |
1499 | /* Paranoia check to be thorough. */ | |
8f760780 JJ |
1500 | kfree(hvcs_index_list); |
1501 | hvcs_index_list = NULL; | |
1502 | hvcs_index_count = 0; | |
1da177e4 LT |
1503 | } |
1504 | ||
1505 | static int __init hvcs_module_init(void) | |
1506 | { | |
1507 | int rc; | |
1508 | int num_ttys_to_alloc; | |
1509 | ||
1510 | printk(KERN_INFO "Initializing %s\n", hvcs_driver_string); | |
1511 | ||
1512 | /* Has the user specified an overload with an insmod param? */ | |
1513 | if (hvcs_parm_num_devs <= 0 || | |
1514 | (hvcs_parm_num_devs > HVCS_MAX_SERVER_ADAPTERS)) { | |
1515 | num_ttys_to_alloc = HVCS_DEFAULT_SERVER_ADAPTERS; | |
1516 | } else | |
1517 | num_ttys_to_alloc = hvcs_parm_num_devs; | |
1518 | ||
1519 | hvcs_tty_driver = alloc_tty_driver(num_ttys_to_alloc); | |
1520 | if (!hvcs_tty_driver) | |
1521 | return -ENOMEM; | |
1522 | ||
c15bb296 LV |
1523 | if (hvcs_alloc_index_list(num_ttys_to_alloc)) { |
1524 | rc = -ENOMEM; | |
1525 | goto index_fail; | |
1526 | } | |
1da177e4 LT |
1527 | |
1528 | hvcs_tty_driver->owner = THIS_MODULE; | |
1529 | ||
1530 | hvcs_tty_driver->driver_name = hvcs_driver_name; | |
1531 | hvcs_tty_driver->name = hvcs_device_node; | |
1da177e4 LT |
1532 | |
1533 | /* | |
1534 | * We'll let the system assign us a major number, indicated by leaving | |
1535 | * it blank. | |
1536 | */ | |
1537 | ||
1538 | hvcs_tty_driver->minor_start = HVCS_MINOR_START; | |
1539 | hvcs_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
1540 | ||
1541 | /* | |
1542 | * We role our own so that we DONT ECHO. We can't echo because the | |
1543 | * device we are connecting to already echoes by default and this would | |
1544 | * throw us into a horrible recursive echo-echo-echo loop. | |
1545 | */ | |
1546 | hvcs_tty_driver->init_termios = hvcs_tty_termios; | |
1547 | hvcs_tty_driver->flags = TTY_DRIVER_REAL_RAW; | |
1548 | ||
1549 | tty_set_operations(hvcs_tty_driver, &hvcs_ops); | |
1550 | ||
1551 | /* | |
1552 | * The following call will result in sysfs entries that denote the | |
1553 | * dynamically assigned major and minor numbers for our devices. | |
1554 | */ | |
1555 | if (tty_register_driver(hvcs_tty_driver)) { | |
c15bb296 LV |
1556 | printk(KERN_ERR "HVCS: registration as a tty driver failed.\n"); |
1557 | rc = -EIO; | |
1558 | goto register_fail; | |
1da177e4 LT |
1559 | } |
1560 | ||
1561 | hvcs_pi_buff = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
1562 | if (!hvcs_pi_buff) { | |
c15bb296 LV |
1563 | rc = -ENOMEM; |
1564 | goto buff_alloc_fail; | |
1da177e4 LT |
1565 | } |
1566 | ||
1567 | hvcs_task = kthread_run(khvcsd, NULL, "khvcsd"); | |
1568 | if (IS_ERR(hvcs_task)) { | |
1569 | printk(KERN_ERR "HVCS: khvcsd creation failed. Driver not loaded.\n"); | |
c15bb296 LV |
1570 | rc = -EIO; |
1571 | goto kthread_fail; | |
1da177e4 LT |
1572 | } |
1573 | ||
1574 | rc = vio_register_driver(&hvcs_vio_driver); | |
c15bb296 LV |
1575 | if (rc) { |
1576 | printk(KERN_ERR "HVCS: can't register vio driver\n"); | |
1577 | goto vio_fail; | |
1578 | } | |
1da177e4 LT |
1579 | |
1580 | /* | |
1581 | * This needs to be done AFTER the vio_register_driver() call or else | |
1582 | * the kobjects won't be initialized properly. | |
1583 | */ | |
c15bb296 LV |
1584 | rc = driver_create_file(&(hvcs_vio_driver.driver), &driver_attr_rescan); |
1585 | if (rc) { | |
1586 | printk(KERN_ERR "HVCS: sysfs attr create failed\n"); | |
1587 | goto attr_fail; | |
1588 | } | |
1da177e4 LT |
1589 | |
1590 | printk(KERN_INFO "HVCS: driver module inserted.\n"); | |
1591 | ||
c15bb296 LV |
1592 | return 0; |
1593 | ||
1594 | attr_fail: | |
1595 | vio_unregister_driver(&hvcs_vio_driver); | |
1596 | vio_fail: | |
1597 | kthread_stop(hvcs_task); | |
1598 | kthread_fail: | |
1599 | kfree(hvcs_pi_buff); | |
1600 | buff_alloc_fail: | |
1601 | tty_unregister_driver(hvcs_tty_driver); | |
1602 | register_fail: | |
1603 | hvcs_free_index_list(); | |
1604 | index_fail: | |
1605 | put_tty_driver(hvcs_tty_driver); | |
1606 | hvcs_tty_driver = NULL; | |
1da177e4 LT |
1607 | return rc; |
1608 | } | |
1609 | ||
1610 | static void __exit hvcs_module_exit(void) | |
1611 | { | |
1612 | /* | |
1613 | * This driver receives hvcs_remove callbacks for each device upon | |
1614 | * module removal. | |
1615 | */ | |
1616 | ||
1617 | /* | |
1618 | * This synchronous operation will wake the khvcsd kthread if it is | |
1619 | * asleep and will return when khvcsd has terminated. | |
1620 | */ | |
1621 | kthread_stop(hvcs_task); | |
1622 | ||
1623 | spin_lock(&hvcs_pi_lock); | |
1624 | kfree(hvcs_pi_buff); | |
1625 | hvcs_pi_buff = NULL; | |
1626 | spin_unlock(&hvcs_pi_lock); | |
1627 | ||
c15bb296 | 1628 | driver_remove_file(&hvcs_vio_driver.driver, &driver_attr_rescan); |
1da177e4 LT |
1629 | |
1630 | vio_unregister_driver(&hvcs_vio_driver); | |
1631 | ||
1632 | tty_unregister_driver(hvcs_tty_driver); | |
1633 | ||
1634 | hvcs_free_index_list(); | |
1635 | ||
1636 | put_tty_driver(hvcs_tty_driver); | |
1637 | ||
1638 | printk(KERN_INFO "HVCS: driver module removed.\n"); | |
1639 | } | |
1640 | ||
1641 | module_init(hvcs_module_init); | |
1642 | module_exit(hvcs_module_exit); |