diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/s390/char/sclp_con.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/s390/char/sclp_con.c')
-rw-r--r-- | drivers/s390/char/sclp_con.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c new file mode 100644 index 000000000000..10ef22f13541 --- /dev/null +++ b/drivers/s390/char/sclp_con.c | |||
@@ -0,0 +1,252 @@ | |||
1 | /* | ||
2 | * drivers/s390/char/sclp_con.c | ||
3 | * SCLP line mode console driver | ||
4 | * | ||
5 | * S390 version | ||
6 | * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation | ||
7 | * Author(s): Martin Peschke <mpeschke@de.ibm.com> | ||
8 | * Martin Schwidefsky <schwidefsky@de.ibm.com> | ||
9 | */ | ||
10 | |||
11 | #include <linux/config.h> | ||
12 | #include <linux/kmod.h> | ||
13 | #include <linux/console.h> | ||
14 | #include <linux/init.h> | ||
15 | #include <linux/timer.h> | ||
16 | #include <linux/jiffies.h> | ||
17 | #include <linux/bootmem.h> | ||
18 | #include <linux/err.h> | ||
19 | |||
20 | #include "sclp.h" | ||
21 | #include "sclp_rw.h" | ||
22 | #include "sclp_tty.h" | ||
23 | |||
24 | #define SCLP_CON_PRINT_HEADER "sclp console driver: " | ||
25 | |||
26 | #define sclp_console_major 4 /* TTYAUX_MAJOR */ | ||
27 | #define sclp_console_minor 64 | ||
28 | #define sclp_console_name "ttyS" | ||
29 | |||
30 | /* Lock to guard over changes to global variables */ | ||
31 | static spinlock_t sclp_con_lock; | ||
32 | /* List of free pages that can be used for console output buffering */ | ||
33 | static struct list_head sclp_con_pages; | ||
34 | /* List of full struct sclp_buffer structures ready for output */ | ||
35 | static struct list_head sclp_con_outqueue; | ||
36 | /* Counter how many buffers are emitted (max 1) and how many */ | ||
37 | /* are on the output queue. */ | ||
38 | static int sclp_con_buffer_count; | ||
39 | /* Pointer to current console buffer */ | ||
40 | static struct sclp_buffer *sclp_conbuf; | ||
41 | /* Timer for delayed output of console messages */ | ||
42 | static struct timer_list sclp_con_timer; | ||
43 | |||
44 | /* Output format for console messages */ | ||
45 | static unsigned short sclp_con_columns; | ||
46 | static unsigned short sclp_con_width_htab; | ||
47 | |||
48 | static void | ||
49 | sclp_conbuf_callback(struct sclp_buffer *buffer, int rc) | ||
50 | { | ||
51 | unsigned long flags; | ||
52 | void *page; | ||
53 | |||
54 | do { | ||
55 | page = sclp_unmake_buffer(buffer); | ||
56 | spin_lock_irqsave(&sclp_con_lock, flags); | ||
57 | /* Remove buffer from outqueue */ | ||
58 | list_del(&buffer->list); | ||
59 | sclp_con_buffer_count--; | ||
60 | list_add_tail((struct list_head *) page, &sclp_con_pages); | ||
61 | /* Check if there is a pending buffer on the out queue. */ | ||
62 | buffer = NULL; | ||
63 | if (!list_empty(&sclp_con_outqueue)) | ||
64 | buffer = list_entry(sclp_con_outqueue.next, | ||
65 | struct sclp_buffer, list); | ||
66 | spin_unlock_irqrestore(&sclp_con_lock, flags); | ||
67 | } while (buffer && sclp_emit_buffer(buffer, sclp_conbuf_callback)); | ||
68 | } | ||
69 | |||
70 | static inline void | ||
71 | sclp_conbuf_emit(void) | ||
72 | { | ||
73 | struct sclp_buffer* buffer; | ||
74 | unsigned long flags; | ||
75 | int count; | ||
76 | int rc; | ||
77 | |||
78 | spin_lock_irqsave(&sclp_con_lock, flags); | ||
79 | buffer = sclp_conbuf; | ||
80 | sclp_conbuf = NULL; | ||
81 | if (buffer == NULL) { | ||
82 | spin_unlock_irqrestore(&sclp_con_lock, flags); | ||
83 | return; | ||
84 | } | ||
85 | list_add_tail(&buffer->list, &sclp_con_outqueue); | ||
86 | count = sclp_con_buffer_count++; | ||
87 | spin_unlock_irqrestore(&sclp_con_lock, flags); | ||
88 | if (count) | ||
89 | return; | ||
90 | rc = sclp_emit_buffer(buffer, sclp_conbuf_callback); | ||
91 | if (rc) | ||
92 | sclp_conbuf_callback(buffer, rc); | ||
93 | } | ||
94 | |||
95 | /* | ||
96 | * When this routine is called from the timer then we flush the | ||
97 | * temporary write buffer without further waiting on a final new line. | ||
98 | */ | ||
99 | static void | ||
100 | sclp_console_timeout(unsigned long data) | ||
101 | { | ||
102 | sclp_conbuf_emit(); | ||
103 | } | ||
104 | |||
105 | /* | ||
106 | * Writes the given message to S390 system console | ||
107 | */ | ||
108 | static void | ||
109 | sclp_console_write(struct console *console, const char *message, | ||
110 | unsigned int count) | ||
111 | { | ||
112 | unsigned long flags; | ||
113 | void *page; | ||
114 | int written; | ||
115 | |||
116 | if (count == 0) | ||
117 | return; | ||
118 | spin_lock_irqsave(&sclp_con_lock, flags); | ||
119 | /* | ||
120 | * process escape characters, write message into buffer, | ||
121 | * send buffer to SCLP | ||
122 | */ | ||
123 | do { | ||
124 | /* make sure we have a console output buffer */ | ||
125 | if (sclp_conbuf == NULL) { | ||
126 | while (list_empty(&sclp_con_pages)) { | ||
127 | spin_unlock_irqrestore(&sclp_con_lock, flags); | ||
128 | sclp_sync_wait(); | ||
129 | spin_lock_irqsave(&sclp_con_lock, flags); | ||
130 | } | ||
131 | page = sclp_con_pages.next; | ||
132 | list_del((struct list_head *) page); | ||
133 | sclp_conbuf = sclp_make_buffer(page, sclp_con_columns, | ||
134 | sclp_con_width_htab); | ||
135 | } | ||
136 | /* try to write the string to the current output buffer */ | ||
137 | written = sclp_write(sclp_conbuf, (const unsigned char *) | ||
138 | message, count); | ||
139 | if (written == count) | ||
140 | break; | ||
141 | /* | ||
142 | * Not all characters could be written to the current | ||
143 | * output buffer. Emit the buffer, create a new buffer | ||
144 | * and then output the rest of the string. | ||
145 | */ | ||
146 | spin_unlock_irqrestore(&sclp_con_lock, flags); | ||
147 | sclp_conbuf_emit(); | ||
148 | spin_lock_irqsave(&sclp_con_lock, flags); | ||
149 | message += written; | ||
150 | count -= written; | ||
151 | } while (count > 0); | ||
152 | /* Setup timer to output current console buffer after 1/10 second */ | ||
153 | if (sclp_conbuf != NULL && sclp_chars_in_buffer(sclp_conbuf) != 0 && | ||
154 | !timer_pending(&sclp_con_timer)) { | ||
155 | init_timer(&sclp_con_timer); | ||
156 | sclp_con_timer.function = sclp_console_timeout; | ||
157 | sclp_con_timer.data = 0UL; | ||
158 | sclp_con_timer.expires = jiffies + HZ/10; | ||
159 | add_timer(&sclp_con_timer); | ||
160 | } | ||
161 | spin_unlock_irqrestore(&sclp_con_lock, flags); | ||
162 | } | ||
163 | |||
164 | static struct tty_driver * | ||
165 | sclp_console_device(struct console *c, int *index) | ||
166 | { | ||
167 | *index = c->index; | ||
168 | return sclp_tty_driver; | ||
169 | } | ||
170 | |||
171 | /* | ||
172 | * This routine is called from panic when the kernel | ||
173 | * is going to give up. We have to make sure that all buffers | ||
174 | * will be flushed to the SCLP. | ||
175 | */ | ||
176 | static void | ||
177 | sclp_console_unblank(void) | ||
178 | { | ||
179 | unsigned long flags; | ||
180 | |||
181 | sclp_conbuf_emit(); | ||
182 | spin_lock_irqsave(&sclp_con_lock, flags); | ||
183 | if (timer_pending(&sclp_con_timer)) | ||
184 | del_timer(&sclp_con_timer); | ||
185 | while (sclp_con_buffer_count > 0) { | ||
186 | spin_unlock_irqrestore(&sclp_con_lock, flags); | ||
187 | sclp_sync_wait(); | ||
188 | spin_lock_irqsave(&sclp_con_lock, flags); | ||
189 | } | ||
190 | spin_unlock_irqrestore(&sclp_con_lock, flags); | ||
191 | } | ||
192 | |||
193 | /* | ||
194 | * used to register the SCLP console to the kernel and to | ||
195 | * give printk necessary information | ||
196 | */ | ||
197 | static struct console sclp_console = | ||
198 | { | ||
199 | .name = sclp_console_name, | ||
200 | .write = sclp_console_write, | ||
201 | .device = sclp_console_device, | ||
202 | .unblank = sclp_console_unblank, | ||
203 | .flags = CON_PRINTBUFFER, | ||
204 | .index = 0 /* ttyS0 */ | ||
205 | }; | ||
206 | |||
207 | /* | ||
208 | * called by console_init() in drivers/char/tty_io.c at boot-time. | ||
209 | */ | ||
210 | static int __init | ||
211 | sclp_console_init(void) | ||
212 | { | ||
213 | void *page; | ||
214 | int i; | ||
215 | int rc; | ||
216 | |||
217 | if (!CONSOLE_IS_SCLP) | ||
218 | return 0; | ||
219 | rc = sclp_rw_init(); | ||
220 | if (rc) | ||
221 | return rc; | ||
222 | /* Allocate pages for output buffering */ | ||
223 | INIT_LIST_HEAD(&sclp_con_pages); | ||
224 | for (i = 0; i < MAX_CONSOLE_PAGES; i++) { | ||
225 | page = alloc_bootmem_low_pages(PAGE_SIZE); | ||
226 | if (page == NULL) | ||
227 | return -ENOMEM; | ||
228 | list_add_tail((struct list_head *) page, &sclp_con_pages); | ||
229 | } | ||
230 | INIT_LIST_HEAD(&sclp_con_outqueue); | ||
231 | spin_lock_init(&sclp_con_lock); | ||
232 | sclp_con_buffer_count = 0; | ||
233 | sclp_conbuf = NULL; | ||
234 | init_timer(&sclp_con_timer); | ||
235 | |||
236 | /* Set output format */ | ||
237 | if (MACHINE_IS_VM) | ||
238 | /* | ||
239 | * save 4 characters for the CPU number | ||
240 | * written at start of each line by VM/CP | ||
241 | */ | ||
242 | sclp_con_columns = 76; | ||
243 | else | ||
244 | sclp_con_columns = 80; | ||
245 | sclp_con_width_htab = 8; | ||
246 | |||
247 | /* enable printk-access to this driver */ | ||
248 | register_console(&sclp_console); | ||
249 | return 0; | ||
250 | } | ||
251 | |||
252 | console_initcall(sclp_console_init); | ||