Commit | Line | Data |
---|---|---|
44a01d5b | 1 | /* |
17e19f04 | 2 | * hvc_iucv.c - z/VM IUCV hypervisor console (HVC) device driver |
44a01d5b | 3 | * |
17e19f04 | 4 | * This HVC device driver provides terminal access using |
44a01d5b HB |
5 | * z/VM IUCV communication paths. |
6 | * | |
17e19f04 | 7 | * Copyright IBM Corp. 2008 |
44a01d5b HB |
8 | * |
9 | * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> | |
10 | */ | |
11 | #define KMSG_COMPONENT "hvc_iucv" | |
17e19f04 | 12 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
44a01d5b HB |
13 | |
14 | #include <linux/types.h> | |
15 | #include <asm/ebcdic.h> | |
c45ce4b5 | 16 | #include <linux/delay.h> |
68c6b3d2 | 17 | #include <linux/init.h> |
44a01d5b HB |
18 | #include <linux/mempool.h> |
19 | #include <linux/module.h> | |
20 | #include <linux/tty.h> | |
c45ce4b5 | 21 | #include <linux/wait.h> |
44a01d5b HB |
22 | #include <net/iucv/iucv.h> |
23 | ||
24 | #include "hvc_console.h" | |
25 | ||
26 | ||
17e19f04 | 27 | /* General device driver settings */ |
44a01d5b HB |
28 | #define HVC_IUCV_MAGIC 0xc9e4c3e5 |
29 | #define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS | |
30 | #define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4) | |
31 | ||
32 | /* IUCV TTY message */ | |
33 | #define MSG_VERSION 0x02 /* Message version */ | |
34 | #define MSG_TYPE_ERROR 0x01 /* Error message */ | |
35 | #define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */ | |
36 | #define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */ | |
37 | #define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */ | |
38 | #define MSG_TYPE_DATA 0x10 /* Terminal data */ | |
39 | ||
44a01d5b HB |
40 | struct iucv_tty_msg { |
41 | u8 version; /* Message version */ | |
42 | u8 type; /* Message type */ | |
c45ce4b5 | 43 | #define MSG_MAX_DATALEN ((u16)(~0)) |
44a01d5b HB |
44 | u16 datalen; /* Payload length */ |
45 | u8 data[]; /* Payload buffer */ | |
46 | } __attribute__((packed)); | |
17e19f04 | 47 | #define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data)) |
44a01d5b HB |
48 | |
49 | enum iucv_state_t { | |
50 | IUCV_DISCONN = 0, | |
51 | IUCV_CONNECTED = 1, | |
52 | IUCV_SEVERED = 2, | |
53 | }; | |
54 | ||
55 | enum tty_state_t { | |
56 | TTY_CLOSED = 0, | |
57 | TTY_OPENED = 1, | |
58 | }; | |
59 | ||
60 | struct hvc_iucv_private { | |
17e19f04 | 61 | struct hvc_struct *hvc; /* HVC struct reference */ |
44a01d5b | 62 | u8 srv_name[8]; /* IUCV service name (ebcdic) */ |
6c089fd3 | 63 | unsigned char is_console; /* Linux console usage flag */ |
44a01d5b HB |
64 | enum iucv_state_t iucv_state; /* IUCV connection status */ |
65 | enum tty_state_t tty_state; /* TTY status */ | |
66 | struct iucv_path *path; /* IUCV path pointer */ | |
67 | spinlock_t lock; /* hvc_iucv_private lock */ | |
c45ce4b5 HB |
68 | #define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */ |
69 | void *sndbuf; /* send buffer */ | |
70 | size_t sndbuf_len; /* length of send buffer */ | |
71 | #define QUEUE_SNDBUF_DELAY (HZ / 25) | |
72 | struct delayed_work sndbuf_work; /* work: send iucv msg(s) */ | |
73 | wait_queue_head_t sndbuf_waitq; /* wait for send completion */ | |
44a01d5b HB |
74 | struct list_head tty_outqueue; /* outgoing IUCV messages */ |
75 | struct list_head tty_inqueue; /* incoming IUCV messages */ | |
76 | }; | |
77 | ||
78 | struct iucv_tty_buffer { | |
79 | struct list_head list; /* list pointer */ | |
17e19f04 | 80 | struct iucv_message msg; /* store an IUCV message */ |
44a01d5b HB |
81 | size_t offset; /* data buffer offset */ |
82 | struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ | |
83 | }; | |
84 | ||
85 | /* IUCV callback handler */ | |
86 | static int hvc_iucv_path_pending(struct iucv_path *, u8[8], u8[16]); | |
87 | static void hvc_iucv_path_severed(struct iucv_path *, u8[16]); | |
88 | static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); | |
89 | static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); | |
90 | ||
91 | ||
2dc184c0 HB |
92 | /* Kernel module parameter: use one terminal device as default */ |
93 | static unsigned long hvc_iucv_devices = 1; | |
44a01d5b HB |
94 | |
95 | /* Array of allocated hvc iucv tty lines... */ | |
96 | static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; | |
6c089fd3 | 97 | #define IUCV_HVC_CON_IDX (0) |
44a01d5b HB |
98 | |
99 | /* Kmem cache and mempool for iucv_tty_buffer elements */ | |
100 | static struct kmem_cache *hvc_iucv_buffer_cache; | |
101 | static mempool_t *hvc_iucv_mempool; | |
102 | ||
103 | /* IUCV handler callback functions */ | |
104 | static struct iucv_handler hvc_iucv_handler = { | |
105 | .path_pending = hvc_iucv_path_pending, | |
106 | .path_severed = hvc_iucv_path_severed, | |
107 | .message_complete = hvc_iucv_msg_complete, | |
108 | .message_pending = hvc_iucv_msg_pending, | |
109 | }; | |
110 | ||
111 | ||
112 | /** | |
113 | * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. | |
114 | * @num: The HVC virtual terminal number (vtermno) | |
115 | * | |
116 | * This function returns the struct hvc_iucv_private instance that corresponds | |
117 | * to the HVC virtual terminal number specified as parameter @num. | |
118 | */ | |
119 | struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) | |
120 | { | |
121 | if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices)) | |
122 | return NULL; | |
123 | return hvc_iucv_table[num - HVC_IUCV_MAGIC]; | |
124 | } | |
125 | ||
126 | /** | |
17e19f04 | 127 | * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element. |
44a01d5b HB |
128 | * @size: Size of the internal buffer used to store data. |
129 | * @flags: Memory allocation flags passed to mempool. | |
130 | * | |
131 | * This function allocates a new struct iucv_tty_buffer element and, optionally, | |
132 | * allocates an internal data buffer with the specified size @size. | |
133 | * Note: The total message size arises from the internal buffer size and the | |
134 | * members of the iucv_tty_msg structure. | |
44a01d5b HB |
135 | * The function returns NULL if memory allocation has failed. |
136 | */ | |
137 | static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) | |
138 | { | |
139 | struct iucv_tty_buffer *bufp; | |
140 | ||
141 | bufp = mempool_alloc(hvc_iucv_mempool, flags); | |
142 | if (!bufp) | |
143 | return NULL; | |
6c089fd3 | 144 | memset(bufp, 0, sizeof(*bufp)); |
44a01d5b HB |
145 | |
146 | if (size > 0) { | |
147 | bufp->msg.length = MSG_SIZE(size); | |
148 | bufp->mbuf = kmalloc(bufp->msg.length, flags); | |
149 | if (!bufp->mbuf) { | |
150 | mempool_free(bufp, hvc_iucv_mempool); | |
151 | return NULL; | |
152 | } | |
153 | bufp->mbuf->version = MSG_VERSION; | |
154 | bufp->mbuf->type = MSG_TYPE_DATA; | |
155 | bufp->mbuf->datalen = (u16) size; | |
156 | } | |
157 | return bufp; | |
158 | } | |
159 | ||
160 | /** | |
161 | * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. | |
162 | * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. | |
44a01d5b HB |
163 | */ |
164 | static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) | |
165 | { | |
166 | kfree(bufp->mbuf); | |
167 | mempool_free(bufp, hvc_iucv_mempool); | |
168 | } | |
169 | ||
170 | /** | |
171 | * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. | |
17e19f04 | 172 | * @list: List containing struct iucv_tty_buffer elements. |
44a01d5b HB |
173 | */ |
174 | static void destroy_tty_buffer_list(struct list_head *list) | |
175 | { | |
176 | struct iucv_tty_buffer *ent, *next; | |
177 | ||
178 | list_for_each_entry_safe(ent, next, list, list) { | |
179 | list_del(&ent->list); | |
180 | destroy_tty_buffer(ent); | |
181 | } | |
182 | } | |
183 | ||
184 | /** | |
17e19f04 HB |
185 | * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer. |
186 | * @priv: Pointer to struct hvc_iucv_private | |
187 | * @buf: HVC buffer for writing received terminal data. | |
188 | * @count: HVC buffer size. | |
44a01d5b HB |
189 | * @has_more_data: Pointer to an int variable. |
190 | * | |
191 | * The function picks up pending messages from the input queue and receives | |
192 | * the message data that is then written to the specified buffer @buf. | |
17e19f04 | 193 | * If the buffer size @count is less than the data message size, the |
44a01d5b | 194 | * message is kept on the input queue and @has_more_data is set to 1. |
17e19f04 | 195 | * If all message data has been written, the message is removed from |
44a01d5b HB |
196 | * the input queue. |
197 | * | |
198 | * The function returns the number of bytes written to the terminal, zero if | |
199 | * there are no pending data messages available or if there is no established | |
200 | * IUCV path. | |
201 | * If the IUCV path has been severed, then -EPIPE is returned to cause a | |
17e19f04 | 202 | * hang up (that is issued by the HVC layer). |
44a01d5b HB |
203 | */ |
204 | static int hvc_iucv_write(struct hvc_iucv_private *priv, | |
205 | char *buf, int count, int *has_more_data) | |
206 | { | |
207 | struct iucv_tty_buffer *rb; | |
208 | int written; | |
209 | int rc; | |
210 | ||
17e19f04 | 211 | /* immediately return if there is no IUCV connection */ |
44a01d5b HB |
212 | if (priv->iucv_state == IUCV_DISCONN) |
213 | return 0; | |
214 | ||
17e19f04 HB |
215 | /* if the IUCV path has been severed, return -EPIPE to inform the |
216 | * HVC layer to hang up the tty device. */ | |
44a01d5b HB |
217 | if (priv->iucv_state == IUCV_SEVERED) |
218 | return -EPIPE; | |
219 | ||
220 | /* check if there are pending messages */ | |
221 | if (list_empty(&priv->tty_inqueue)) | |
222 | return 0; | |
223 | ||
17e19f04 | 224 | /* receive an iucv message and flip data to the tty (ldisc) */ |
44a01d5b HB |
225 | rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); |
226 | ||
227 | written = 0; | |
228 | if (!rb->mbuf) { /* message not yet received ... */ | |
229 | /* allocate mem to store msg data; if no memory is available | |
230 | * then leave the buffer on the list and re-try later */ | |
231 | rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC); | |
232 | if (!rb->mbuf) | |
233 | return -ENOMEM; | |
234 | ||
235 | rc = __iucv_message_receive(priv->path, &rb->msg, 0, | |
236 | rb->mbuf, rb->msg.length, NULL); | |
237 | switch (rc) { | |
238 | case 0: /* Successful */ | |
239 | break; | |
240 | case 2: /* No message found */ | |
241 | case 9: /* Message purged */ | |
242 | break; | |
243 | default: | |
244 | written = -EIO; | |
245 | } | |
246 | /* remove buffer if an error has occured or received data | |
247 | * is not correct */ | |
248 | if (rc || (rb->mbuf->version != MSG_VERSION) || | |
249 | (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) | |
250 | goto out_remove_buffer; | |
251 | } | |
252 | ||
253 | switch (rb->mbuf->type) { | |
254 | case MSG_TYPE_DATA: | |
255 | written = min_t(int, rb->mbuf->datalen - rb->offset, count); | |
256 | memcpy(buf, rb->mbuf->data + rb->offset, written); | |
257 | if (written < (rb->mbuf->datalen - rb->offset)) { | |
258 | rb->offset += written; | |
259 | *has_more_data = 1; | |
260 | goto out_written; | |
261 | } | |
262 | break; | |
263 | ||
264 | case MSG_TYPE_WINSIZE: | |
265 | if (rb->mbuf->datalen != sizeof(struct winsize)) | |
266 | break; | |
17e19f04 | 267 | hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data)); |
44a01d5b HB |
268 | break; |
269 | ||
270 | case MSG_TYPE_ERROR: /* ignored ... */ | |
271 | case MSG_TYPE_TERMENV: /* ignored ... */ | |
272 | case MSG_TYPE_TERMIOS: /* ignored ... */ | |
273 | break; | |
274 | } | |
275 | ||
276 | out_remove_buffer: | |
277 | list_del(&rb->list); | |
278 | destroy_tty_buffer(rb); | |
279 | *has_more_data = !list_empty(&priv->tty_inqueue); | |
280 | ||
281 | out_written: | |
282 | return written; | |
283 | } | |
284 | ||
285 | /** | |
286 | * hvc_iucv_get_chars() - HVC get_chars operation. | |
287 | * @vtermno: HVC virtual terminal number. | |
288 | * @buf: Pointer to a buffer to store data | |
289 | * @count: Size of buffer available for writing | |
290 | * | |
17e19f04 HB |
291 | * The HVC thread calls this method to read characters from the back-end. |
292 | * If an IUCV communication path has been established, pending IUCV messages | |
293 | * are received and data is copied into buffer @buf up to @count bytes. | |
44a01d5b HB |
294 | * |
295 | * Locking: The routine gets called under an irqsave() spinlock; and | |
296 | * the routine locks the struct hvc_iucv_private->lock to call | |
297 | * helper functions. | |
298 | */ | |
299 | static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) | |
300 | { | |
301 | struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); | |
302 | int written; | |
303 | int has_more_data; | |
304 | ||
305 | if (count <= 0) | |
306 | return 0; | |
307 | ||
308 | if (!priv) | |
309 | return -ENODEV; | |
310 | ||
311 | spin_lock(&priv->lock); | |
312 | has_more_data = 0; | |
313 | written = hvc_iucv_write(priv, buf, count, &has_more_data); | |
314 | spin_unlock(&priv->lock); | |
315 | ||
316 | /* if there are still messages on the queue... schedule another run */ | |
317 | if (has_more_data) | |
318 | hvc_kick(); | |
319 | ||
320 | return written; | |
321 | } | |
322 | ||
323 | /** | |
c45ce4b5 | 324 | * hvc_iucv_queue() - Buffer terminal data for sending. |
44a01d5b HB |
325 | * @priv: Pointer to struct hvc_iucv_private instance. |
326 | * @buf: Buffer containing data to send. | |
c45ce4b5 | 327 | * @count: Size of buffer and amount of data to send. |
44a01d5b | 328 | * |
c45ce4b5 | 329 | * The function queues data for sending. To actually send the buffered data, |
17e19f04 | 330 | * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY). |
c45ce4b5 | 331 | * The function returns the number of data bytes that has been buffered. |
44a01d5b | 332 | * |
c45ce4b5 HB |
333 | * If the device is not connected, data is ignored and the function returns |
334 | * @count. | |
335 | * If the buffer is full, the function returns 0. | |
17e19f04 HB |
336 | * If an existing IUCV communicaton path has been severed, -EPIPE is returned |
337 | * (that can be passed to HVC layer to cause a tty hangup). | |
44a01d5b | 338 | */ |
c45ce4b5 | 339 | static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, |
17e19f04 | 340 | int count) |
c45ce4b5 HB |
341 | { |
342 | size_t len; | |
343 | ||
344 | if (priv->iucv_state == IUCV_DISCONN) | |
345 | return count; /* ignore data */ | |
346 | ||
347 | if (priv->iucv_state == IUCV_SEVERED) | |
348 | return -EPIPE; | |
349 | ||
350 | len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len); | |
351 | if (!len) | |
352 | return 0; | |
353 | ||
354 | memcpy(priv->sndbuf + priv->sndbuf_len, buf, len); | |
355 | priv->sndbuf_len += len; | |
356 | ||
357 | if (priv->iucv_state == IUCV_CONNECTED) | |
358 | schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY); | |
359 | ||
360 | return len; | |
361 | } | |
362 | ||
363 | /** | |
364 | * hvc_iucv_send() - Send an IUCV message containing terminal data. | |
365 | * @priv: Pointer to struct hvc_iucv_private instance. | |
366 | * | |
17e19f04 HB |
367 | * If an IUCV communication path has been established, the buffered output data |
368 | * is sent via an IUCV message and the number of bytes sent is returned. | |
369 | * Returns 0 if there is no established IUCV communication path or | |
370 | * -EPIPE if an existing IUCV communicaton path has been severed. | |
c45ce4b5 HB |
371 | */ |
372 | static int hvc_iucv_send(struct hvc_iucv_private *priv) | |
44a01d5b HB |
373 | { |
374 | struct iucv_tty_buffer *sb; | |
c45ce4b5 | 375 | int rc, len; |
44a01d5b HB |
376 | |
377 | if (priv->iucv_state == IUCV_SEVERED) | |
378 | return -EPIPE; | |
379 | ||
380 | if (priv->iucv_state == IUCV_DISCONN) | |
c45ce4b5 | 381 | return -EIO; |
44a01d5b | 382 | |
c45ce4b5 HB |
383 | if (!priv->sndbuf_len) |
384 | return 0; | |
44a01d5b HB |
385 | |
386 | /* allocate internal buffer to store msg data and also compute total | |
387 | * message length */ | |
c45ce4b5 | 388 | sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC); |
44a01d5b HB |
389 | if (!sb) |
390 | return -ENOMEM; | |
391 | ||
c45ce4b5 HB |
392 | memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len); |
393 | sb->mbuf->datalen = (u16) priv->sndbuf_len; | |
394 | sb->msg.length = MSG_SIZE(sb->mbuf->datalen); | |
44a01d5b HB |
395 | |
396 | list_add_tail(&sb->list, &priv->tty_outqueue); | |
397 | ||
398 | rc = __iucv_message_send(priv->path, &sb->msg, 0, 0, | |
399 | (void *) sb->mbuf, sb->msg.length); | |
400 | if (rc) { | |
c45ce4b5 HB |
401 | /* drop the message here; however we might want to handle |
402 | * 0x03 (msg limit reached) by trying again... */ | |
44a01d5b HB |
403 | list_del(&sb->list); |
404 | destroy_tty_buffer(sb); | |
44a01d5b | 405 | } |
c45ce4b5 HB |
406 | len = priv->sndbuf_len; |
407 | priv->sndbuf_len = 0; | |
44a01d5b HB |
408 | |
409 | return len; | |
410 | } | |
411 | ||
c45ce4b5 HB |
412 | /** |
413 | * hvc_iucv_sndbuf_work() - Send buffered data over IUCV | |
414 | * @work: Work structure. | |
415 | * | |
17e19f04 HB |
416 | * This work queue function sends buffered output data over IUCV and, |
417 | * if not all buffered data could be sent, reschedules itself. | |
c45ce4b5 HB |
418 | */ |
419 | static void hvc_iucv_sndbuf_work(struct work_struct *work) | |
420 | { | |
421 | struct hvc_iucv_private *priv; | |
422 | ||
423 | priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work); | |
c45ce4b5 HB |
424 | if (!priv) |
425 | return; | |
426 | ||
427 | spin_lock_bh(&priv->lock); | |
428 | hvc_iucv_send(priv); | |
429 | spin_unlock_bh(&priv->lock); | |
430 | } | |
431 | ||
44a01d5b HB |
432 | /** |
433 | * hvc_iucv_put_chars() - HVC put_chars operation. | |
434 | * @vtermno: HVC virtual terminal number. | |
435 | * @buf: Pointer to an buffer to read data from | |
436 | * @count: Size of buffer available for reading | |
437 | * | |
17e19f04 HB |
438 | * The HVC thread calls this method to write characters to the back-end. |
439 | * The function calls hvc_iucv_queue() to queue terminal data for sending. | |
44a01d5b HB |
440 | * |
441 | * Locking: The method gets called under an irqsave() spinlock; and | |
442 | * locks struct hvc_iucv_private->lock. | |
443 | */ | |
444 | static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) | |
445 | { | |
446 | struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); | |
c45ce4b5 | 447 | int queued; |
44a01d5b HB |
448 | |
449 | if (count <= 0) | |
450 | return 0; | |
451 | ||
452 | if (!priv) | |
453 | return -ENODEV; | |
454 | ||
455 | spin_lock(&priv->lock); | |
c45ce4b5 | 456 | queued = hvc_iucv_queue(priv, buf, count); |
44a01d5b HB |
457 | spin_unlock(&priv->lock); |
458 | ||
c45ce4b5 | 459 | return queued; |
44a01d5b HB |
460 | } |
461 | ||
462 | /** | |
463 | * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. | |
464 | * @hp: Pointer to the HVC device (struct hvc_struct) | |
465 | * @id: Additional data (originally passed to hvc_alloc): the index of an struct | |
466 | * hvc_iucv_private instance. | |
467 | * | |
6c089fd3 | 468 | * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private |
44a01d5b HB |
469 | * instance that is derived from @id. Always returns 0. |
470 | * | |
471 | * Locking: struct hvc_iucv_private->lock, spin_lock_bh | |
472 | */ | |
473 | static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) | |
474 | { | |
475 | struct hvc_iucv_private *priv; | |
476 | ||
477 | priv = hvc_iucv_get_private(id); | |
478 | if (!priv) | |
479 | return 0; | |
480 | ||
481 | spin_lock_bh(&priv->lock); | |
482 | priv->tty_state = TTY_OPENED; | |
483 | spin_unlock_bh(&priv->lock); | |
484 | ||
485 | return 0; | |
486 | } | |
487 | ||
488 | /** | |
17e19f04 | 489 | * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. |
44a01d5b | 490 | * @priv: Pointer to the struct hvc_iucv_private instance. |
44a01d5b HB |
491 | */ |
492 | static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) | |
493 | { | |
494 | destroy_tty_buffer_list(&priv->tty_outqueue); | |
495 | destroy_tty_buffer_list(&priv->tty_inqueue); | |
496 | ||
497 | priv->tty_state = TTY_CLOSED; | |
498 | priv->iucv_state = IUCV_DISCONN; | |
c45ce4b5 HB |
499 | |
500 | priv->sndbuf_len = 0; | |
501 | } | |
502 | ||
503 | /** | |
504 | * tty_outqueue_empty() - Test if the tty outq is empty | |
505 | * @priv: Pointer to struct hvc_iucv_private instance. | |
506 | */ | |
507 | static inline int tty_outqueue_empty(struct hvc_iucv_private *priv) | |
508 | { | |
509 | int rc; | |
510 | ||
511 | spin_lock_bh(&priv->lock); | |
512 | rc = list_empty(&priv->tty_outqueue); | |
513 | spin_unlock_bh(&priv->lock); | |
514 | ||
515 | return rc; | |
516 | } | |
517 | ||
518 | /** | |
519 | * flush_sndbuf_sync() - Flush send buffer and wait for completion | |
520 | * @priv: Pointer to struct hvc_iucv_private instance. | |
521 | * | |
522 | * The routine cancels a pending sndbuf work, calls hvc_iucv_send() | |
523 | * to flush any buffered terminal output data and waits for completion. | |
524 | */ | |
525 | static void flush_sndbuf_sync(struct hvc_iucv_private *priv) | |
526 | { | |
527 | int sync_wait; | |
528 | ||
529 | cancel_delayed_work_sync(&priv->sndbuf_work); | |
530 | ||
531 | spin_lock_bh(&priv->lock); | |
532 | hvc_iucv_send(priv); /* force sending buffered data */ | |
533 | sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */ | |
534 | spin_unlock_bh(&priv->lock); | |
535 | ||
536 | if (sync_wait) | |
537 | wait_event_timeout(priv->sndbuf_waitq, | |
538 | tty_outqueue_empty(priv), HZ); | |
44a01d5b HB |
539 | } |
540 | ||
541 | /** | |
17e19f04 HB |
542 | * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups. |
543 | * @hp: Pointer to the HVC device (struct hvc_struct) | |
544 | * @id: Additional data (originally passed to hvc_alloc): | |
545 | * the index of an struct hvc_iucv_private instance. | |
44a01d5b | 546 | * |
17e19f04 | 547 | * This routine notifies the HVC back-end that a tty hangup (carrier loss, |
44a01d5b | 548 | * virtual or otherwise) has occured. |
17e19f04 HB |
549 | * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup()) |
550 | * to keep an existing IUCV communication path established. | |
44a01d5b HB |
551 | * (Background: vhangup() is called from user space (by getty or login) to |
552 | * disable writing to the tty by other applications). | |
17e19f04 HB |
553 | * If the tty has been opened and an established IUCV path has been severed |
554 | * (we caused the tty hangup), the function calls hvc_iucv_cleanup(). | |
44a01d5b HB |
555 | * |
556 | * Locking: struct hvc_iucv_private->lock | |
557 | */ | |
558 | static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) | |
559 | { | |
560 | struct hvc_iucv_private *priv; | |
561 | ||
562 | priv = hvc_iucv_get_private(id); | |
563 | if (!priv) | |
564 | return; | |
565 | ||
c45ce4b5 HB |
566 | flush_sndbuf_sync(priv); |
567 | ||
44a01d5b HB |
568 | spin_lock_bh(&priv->lock); |
569 | /* NOTE: If the hangup was scheduled by ourself (from the iucv | |
17e19f04 HB |
570 | * path_servered callback [IUCV_SEVERED]), we have to clean up |
571 | * our structure and to set state to TTY_CLOSED. | |
44a01d5b HB |
572 | * If the tty was hung up otherwise (e.g. vhangup()), then we |
573 | * ignore this hangup and keep an established IUCV path open... | |
574 | * (...the reason is that we are not able to connect back to the | |
575 | * client if we disconnect on hang up) */ | |
576 | priv->tty_state = TTY_CLOSED; | |
577 | ||
578 | if (priv->iucv_state == IUCV_SEVERED) | |
579 | hvc_iucv_cleanup(priv); | |
580 | spin_unlock_bh(&priv->lock); | |
581 | } | |
582 | ||
583 | /** | |
584 | * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. | |
585 | * @hp: Pointer to the HVC device (struct hvc_struct) | |
586 | * @id: Additional data (originally passed to hvc_alloc): | |
587 | * the index of an struct hvc_iucv_private instance. | |
588 | * | |
17e19f04 HB |
589 | * This routine notifies the HVC back-end that the last tty device fd has been |
590 | * closed. The function calls hvc_iucv_cleanup() to clean up the struct | |
591 | * hvc_iucv_private instance. | |
44a01d5b HB |
592 | * |
593 | * Locking: struct hvc_iucv_private->lock | |
594 | */ | |
595 | static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) | |
596 | { | |
597 | struct hvc_iucv_private *priv; | |
598 | struct iucv_path *path; | |
599 | ||
600 | priv = hvc_iucv_get_private(id); | |
601 | if (!priv) | |
602 | return; | |
603 | ||
c45ce4b5 HB |
604 | flush_sndbuf_sync(priv); |
605 | ||
44a01d5b HB |
606 | spin_lock_bh(&priv->lock); |
607 | path = priv->path; /* save reference to IUCV path */ | |
608 | priv->path = NULL; | |
609 | hvc_iucv_cleanup(priv); | |
610 | spin_unlock_bh(&priv->lock); | |
611 | ||
612 | /* sever IUCV path outside of priv->lock due to lock ordering of: | |
613 | * priv->lock <--> iucv_table_lock */ | |
614 | if (path) { | |
615 | iucv_path_sever(path, NULL); | |
616 | iucv_path_free(path); | |
617 | } | |
618 | } | |
619 | ||
620 | /** | |
621 | * hvc_iucv_path_pending() - IUCV handler to process a connection request. | |
622 | * @path: Pending path (struct iucv_path) | |
17e19f04 | 623 | * @ipvmid: z/VM system identifier of originator |
44a01d5b HB |
624 | * @ipuser: User specified data for this path |
625 | * (AF_IUCV: port/service name and originator port) | |
626 | * | |
17e19f04 HB |
627 | * The function uses the @ipuser data to determine if the pending path belongs |
628 | * to a terminal managed by this device driver. | |
629 | * If the path belongs to this driver, ensure that the terminal is not accessed | |
630 | * multiple times (only one connection to a terminal is allowed). | |
631 | * If the terminal is not yet connected, the pending path is accepted and is | |
632 | * associated to the appropriate struct hvc_iucv_private instance. | |
44a01d5b | 633 | * |
17e19f04 | 634 | * Returns 0 if @path belongs to a terminal managed by the this device driver; |
44a01d5b HB |
635 | * otherwise returns -ENODEV in order to dispatch this path to other handlers. |
636 | * | |
637 | * Locking: struct hvc_iucv_private->lock | |
638 | */ | |
639 | static int hvc_iucv_path_pending(struct iucv_path *path, | |
640 | u8 ipvmid[8], u8 ipuser[16]) | |
641 | { | |
642 | struct hvc_iucv_private *priv; | |
643 | u8 nuser_data[16]; | |
644 | int i, rc; | |
645 | ||
646 | priv = NULL; | |
647 | for (i = 0; i < hvc_iucv_devices; i++) | |
648 | if (hvc_iucv_table[i] && | |
649 | (0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) { | |
650 | priv = hvc_iucv_table[i]; | |
651 | break; | |
652 | } | |
44a01d5b HB |
653 | if (!priv) |
654 | return -ENODEV; | |
655 | ||
656 | spin_lock(&priv->lock); | |
657 | ||
658 | /* If the terminal is already connected or being severed, then sever | |
659 | * this path to enforce that there is only ONE established communication | |
660 | * path per terminal. */ | |
661 | if (priv->iucv_state != IUCV_DISCONN) { | |
662 | iucv_path_sever(path, ipuser); | |
663 | iucv_path_free(path); | |
664 | goto out_path_handled; | |
665 | } | |
666 | ||
667 | /* accept path */ | |
668 | memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ | |
669 | memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ | |
670 | path->msglim = 0xffff; /* IUCV MSGLIMIT */ | |
671 | path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ | |
672 | rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); | |
673 | if (rc) { | |
674 | iucv_path_sever(path, ipuser); | |
675 | iucv_path_free(path); | |
676 | goto out_path_handled; | |
677 | } | |
678 | priv->path = path; | |
679 | priv->iucv_state = IUCV_CONNECTED; | |
680 | ||
c45ce4b5 HB |
681 | /* flush buffered output data... */ |
682 | schedule_delayed_work(&priv->sndbuf_work, 5); | |
683 | ||
44a01d5b HB |
684 | out_path_handled: |
685 | spin_unlock(&priv->lock); | |
686 | return 0; | |
687 | } | |
688 | ||
689 | /** | |
690 | * hvc_iucv_path_severed() - IUCV handler to process a path sever. | |
691 | * @path: Pending path (struct iucv_path) | |
692 | * @ipuser: User specified data for this path | |
693 | * (AF_IUCV: port/service name and originator port) | |
694 | * | |
695 | * The function also severs the path (as required by the IUCV protocol) and | |
696 | * sets the iucv state to IUCV_SEVERED for the associated struct | |
697 | * hvc_iucv_private instance. Later, the IUCV_SEVERED state triggers a tty | |
698 | * hangup (hvc_iucv_get_chars() / hvc_iucv_write()). | |
17e19f04 | 699 | * If tty portion of the HVC is closed, clean up the outqueue. |
44a01d5b HB |
700 | * |
701 | * Locking: struct hvc_iucv_private->lock | |
702 | */ | |
703 | static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) | |
704 | { | |
705 | struct hvc_iucv_private *priv = path->private; | |
706 | ||
707 | spin_lock(&priv->lock); | |
708 | priv->iucv_state = IUCV_SEVERED; | |
709 | ||
c45ce4b5 HB |
710 | /* If the tty has not yet been opened, clean up the hvc_iucv_private |
711 | * structure to allow re-connects. | |
6c089fd3 HB |
712 | * This is also done for our console device because console hangups |
713 | * are handled specially and no notifier is called by HVC. | |
714 | * The tty session is active (TTY_OPEN) and ready for re-connects... | |
44a01d5b | 715 | * |
c45ce4b5 HB |
716 | * If it has been opened, let get_chars() return -EPIPE to signal the |
717 | * HVC layer to hang up the tty. | |
718 | * If so, we need to wake up the HVC thread to call get_chars()... | |
719 | */ | |
44a01d5b HB |
720 | priv->path = NULL; |
721 | if (priv->tty_state == TTY_CLOSED) | |
722 | hvc_iucv_cleanup(priv); | |
c45ce4b5 | 723 | else |
6c089fd3 HB |
724 | if (priv->is_console) { |
725 | hvc_iucv_cleanup(priv); | |
726 | priv->tty_state = TTY_OPENED; | |
727 | } else | |
728 | hvc_kick(); | |
44a01d5b HB |
729 | spin_unlock(&priv->lock); |
730 | ||
731 | /* finally sever path (outside of priv->lock due to lock ordering) */ | |
732 | iucv_path_sever(path, ipuser); | |
733 | iucv_path_free(path); | |
734 | } | |
735 | ||
736 | /** | |
737 | * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. | |
738 | * @path: Pending path (struct iucv_path) | |
739 | * @msg: Pointer to the IUCV message | |
740 | * | |
17e19f04 | 741 | * The function puts an incoming message on the input queue for later |
44a01d5b | 742 | * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). |
17e19f04 | 743 | * If the tty has not yet been opened, the message is rejected. |
44a01d5b HB |
744 | * |
745 | * Locking: struct hvc_iucv_private->lock | |
746 | */ | |
747 | static void hvc_iucv_msg_pending(struct iucv_path *path, | |
748 | struct iucv_message *msg) | |
749 | { | |
750 | struct hvc_iucv_private *priv = path->private; | |
751 | struct iucv_tty_buffer *rb; | |
752 | ||
c45ce4b5 HB |
753 | /* reject messages that exceed max size of iucv_tty_msg->datalen */ |
754 | if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { | |
755 | iucv_message_reject(path, msg); | |
756 | return; | |
757 | } | |
758 | ||
44a01d5b HB |
759 | spin_lock(&priv->lock); |
760 | ||
761 | /* reject messages if tty has not yet been opened */ | |
762 | if (priv->tty_state == TTY_CLOSED) { | |
763 | iucv_message_reject(path, msg); | |
764 | goto unlock_return; | |
765 | } | |
766 | ||
c45ce4b5 | 767 | /* allocate tty buffer to save iucv msg only */ |
44a01d5b HB |
768 | rb = alloc_tty_buffer(0, GFP_ATOMIC); |
769 | if (!rb) { | |
770 | iucv_message_reject(path, msg); | |
771 | goto unlock_return; /* -ENOMEM */ | |
772 | } | |
773 | rb->msg = *msg; | |
774 | ||
775 | list_add_tail(&rb->list, &priv->tty_inqueue); | |
776 | ||
17e19f04 | 777 | hvc_kick(); /* wake up hvc thread */ |
44a01d5b HB |
778 | |
779 | unlock_return: | |
780 | spin_unlock(&priv->lock); | |
781 | } | |
782 | ||
783 | /** | |
784 | * hvc_iucv_msg_complete() - IUCV handler to process message completion | |
785 | * @path: Pending path (struct iucv_path) | |
786 | * @msg: Pointer to the IUCV message | |
787 | * | |
17e19f04 HB |
788 | * The function is called upon completion of message delivery to remove the |
789 | * message from the outqueue. Additional delivery information can be found | |
790 | * msg->audit: rejected messages (0x040000 (IPADRJCT)), and | |
791 | * purged messages (0x010000 (IPADPGNR)). | |
44a01d5b HB |
792 | * |
793 | * Locking: struct hvc_iucv_private->lock | |
794 | */ | |
795 | static void hvc_iucv_msg_complete(struct iucv_path *path, | |
796 | struct iucv_message *msg) | |
797 | { | |
798 | struct hvc_iucv_private *priv = path->private; | |
799 | struct iucv_tty_buffer *ent, *next; | |
800 | LIST_HEAD(list_remove); | |
801 | ||
802 | spin_lock(&priv->lock); | |
803 | list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) | |
804 | if (ent->msg.id == msg->id) { | |
805 | list_move(&ent->list, &list_remove); | |
806 | break; | |
807 | } | |
c45ce4b5 | 808 | wake_up(&priv->sndbuf_waitq); |
44a01d5b HB |
809 | spin_unlock(&priv->lock); |
810 | destroy_tty_buffer_list(&list_remove); | |
811 | } | |
812 | ||
813 | ||
814 | /* HVC operations */ | |
815 | static struct hv_ops hvc_iucv_ops = { | |
816 | .get_chars = hvc_iucv_get_chars, | |
817 | .put_chars = hvc_iucv_put_chars, | |
818 | .notifier_add = hvc_iucv_notifier_add, | |
819 | .notifier_del = hvc_iucv_notifier_del, | |
820 | .notifier_hangup = hvc_iucv_notifier_hangup, | |
821 | }; | |
822 | ||
823 | /** | |
824 | * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance | |
6c089fd3 HB |
825 | * @id: hvc_iucv_table index |
826 | * @is_console: Flag if the instance is used as Linux console | |
44a01d5b | 827 | * |
17e19f04 HB |
828 | * This function allocates a new hvc_iucv_private structure and stores |
829 | * the instance in hvc_iucv_table at index @id. | |
44a01d5b HB |
830 | * Returns 0 on success; otherwise non-zero. |
831 | */ | |
6c089fd3 | 832 | static int __init hvc_iucv_alloc(int id, unsigned int is_console) |
44a01d5b HB |
833 | { |
834 | struct hvc_iucv_private *priv; | |
835 | char name[9]; | |
836 | int rc; | |
837 | ||
838 | priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); | |
839 | if (!priv) | |
840 | return -ENOMEM; | |
841 | ||
842 | spin_lock_init(&priv->lock); | |
843 | INIT_LIST_HEAD(&priv->tty_outqueue); | |
844 | INIT_LIST_HEAD(&priv->tty_inqueue); | |
c45ce4b5 HB |
845 | INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); |
846 | init_waitqueue_head(&priv->sndbuf_waitq); | |
847 | ||
848 | priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); | |
849 | if (!priv->sndbuf) { | |
850 | kfree(priv); | |
851 | return -ENOMEM; | |
852 | } | |
44a01d5b | 853 | |
6c089fd3 HB |
854 | /* set console flag */ |
855 | priv->is_console = is_console; | |
856 | ||
17e19f04 | 857 | /* finally allocate hvc */ |
c45ce4b5 HB |
858 | priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */ |
859 | HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256); | |
44a01d5b HB |
860 | if (IS_ERR(priv->hvc)) { |
861 | rc = PTR_ERR(priv->hvc); | |
c45ce4b5 | 862 | free_page((unsigned long) priv->sndbuf); |
44a01d5b HB |
863 | kfree(priv); |
864 | return rc; | |
865 | } | |
866 | ||
17e19f04 | 867 | /* notify HVC thread instead of using polling */ |
c45ce4b5 HB |
868 | priv->hvc->irq_requested = 1; |
869 | ||
44a01d5b | 870 | /* setup iucv related information */ |
2dc184c0 | 871 | snprintf(name, 9, "lnxhvc%-2d", id); |
44a01d5b HB |
872 | memcpy(priv->srv_name, name, 8); |
873 | ASCEBC(priv->srv_name, 8); | |
874 | ||
875 | hvc_iucv_table[id] = priv; | |
876 | return 0; | |
877 | } | |
878 | ||
879 | /** | |
17e19f04 | 880 | * hvc_iucv_init() - z/VM IUCV HVC device driver initialization |
44a01d5b HB |
881 | */ |
882 | static int __init hvc_iucv_init(void) | |
883 | { | |
6c089fd3 HB |
884 | int rc; |
885 | unsigned int i; | |
44a01d5b HB |
886 | |
887 | if (!MACHINE_IS_VM) { | |
c45ce4b5 HB |
888 | pr_info("The z/VM IUCV HVC device driver cannot " |
889 | "be used without z/VM\n"); | |
44a01d5b HB |
890 | return -ENODEV; |
891 | } | |
892 | ||
893 | if (!hvc_iucv_devices) | |
894 | return -ENODEV; | |
895 | ||
896 | if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) | |
897 | return -EINVAL; | |
898 | ||
899 | hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, | |
900 | sizeof(struct iucv_tty_buffer), | |
901 | 0, 0, NULL); | |
902 | if (!hvc_iucv_buffer_cache) { | |
c45ce4b5 | 903 | pr_err("Allocating memory failed with reason code=%d\n", 1); |
44a01d5b HB |
904 | return -ENOMEM; |
905 | } | |
906 | ||
907 | hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, | |
908 | hvc_iucv_buffer_cache); | |
909 | if (!hvc_iucv_mempool) { | |
c45ce4b5 | 910 | pr_err("Allocating memory failed with reason code=%d\n", 2); |
44a01d5b HB |
911 | kmem_cache_destroy(hvc_iucv_buffer_cache); |
912 | return -ENOMEM; | |
913 | } | |
914 | ||
68c6b3d2 HB |
915 | /* register the first terminal device as console |
916 | * (must be done before allocating hvc terminal devices) */ | |
6c089fd3 HB |
917 | rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops); |
918 | if (rc) { | |
919 | pr_err("Registering HVC terminal device as " | |
920 | "Linux console failed\n"); | |
921 | goto out_error_memory; | |
922 | } | |
68c6b3d2 | 923 | |
44a01d5b HB |
924 | /* allocate hvc_iucv_private structs */ |
925 | for (i = 0; i < hvc_iucv_devices; i++) { | |
6c089fd3 | 926 | rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0); |
44a01d5b | 927 | if (rc) { |
c45ce4b5 | 928 | pr_err("Creating a new HVC terminal device " |
17e19f04 | 929 | "failed with error code=%d\n", rc); |
44a01d5b HB |
930 | goto out_error_hvc; |
931 | } | |
932 | } | |
933 | ||
934 | /* register IUCV callback handler */ | |
935 | rc = iucv_register(&hvc_iucv_handler, 0); | |
936 | if (rc) { | |
c45ce4b5 HB |
937 | pr_err("Registering IUCV handlers failed with error code=%d\n", |
938 | rc); | |
44a01d5b HB |
939 | goto out_error_iucv; |
940 | } | |
941 | ||
942 | return 0; | |
943 | ||
944 | out_error_iucv: | |
945 | iucv_unregister(&hvc_iucv_handler, 0); | |
946 | out_error_hvc: | |
947 | for (i = 0; i < hvc_iucv_devices; i++) | |
948 | if (hvc_iucv_table[i]) { | |
949 | if (hvc_iucv_table[i]->hvc) | |
950 | hvc_remove(hvc_iucv_table[i]->hvc); | |
951 | kfree(hvc_iucv_table[i]); | |
952 | } | |
6c089fd3 | 953 | out_error_memory: |
44a01d5b HB |
954 | mempool_destroy(hvc_iucv_mempool); |
955 | kmem_cache_destroy(hvc_iucv_buffer_cache); | |
956 | return rc; | |
957 | } | |
958 | ||
44a01d5b HB |
959 | /** |
960 | * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter | |
961 | * @val: Parameter value (numeric) | |
962 | */ | |
963 | static int __init hvc_iucv_config(char *val) | |
964 | { | |
965 | return strict_strtoul(val, 10, &hvc_iucv_devices); | |
966 | } | |
967 | ||
968 | ||
68c6b3d2 | 969 | device_initcall(hvc_iucv_init); |
44a01d5b | 970 | __setup("hvc_iucv=", hvc_iucv_config); |