| /* |
| * SCLP line mode terminal driver. |
| * |
| * S390 version |
| * Copyright IBM Corp. 1999 |
| * Author(s): Martin Peschke <mpeschke@de.ibm.com> |
| * Martin Schwidefsky <schwidefsky@de.ibm.com> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kmod.h> |
| #include <linux/tty.h> |
| #include <linux/tty_driver.h> |
| #include <linux/tty_flip.h> |
| #include <linux/err.h> |
| #include <linux/init.h> |
| #include <linux/interrupt.h> |
| #include <linux/gfp.h> |
| #include <asm/uaccess.h> |
| |
| #include "ctrlchar.h" |
| #include "sclp.h" |
| #include "sclp_rw.h" |
| #include "sclp_tty.h" |
| |
| /* |
| * size of a buffer that collects single characters coming in |
| * via sclp_tty_put_char() |
| */ |
| #define SCLP_TTY_BUF_SIZE 512 |
| |
| /* |
| * There is exactly one SCLP terminal, so we can keep things simple |
| * and allocate all variables statically. |
| */ |
| |
| /* Lock to guard over changes to global variables. */ |
| static spinlock_t sclp_tty_lock; |
| /* List of free pages that can be used for console output buffering. */ |
| static struct list_head sclp_tty_pages; |
| /* List of full struct sclp_buffer structures ready for output. */ |
| static struct list_head sclp_tty_outqueue; |
| /* Counter how many buffers are emitted. */ |
| static int sclp_tty_buffer_count; |
| /* Pointer to current console buffer. */ |
| static struct sclp_buffer *sclp_ttybuf; |
| /* Timer for delayed output of console messages. */ |
| static struct timer_list sclp_tty_timer; |
| |
| static struct tty_port sclp_port; |
| static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE]; |
| static unsigned short int sclp_tty_chars_count; |
| |
| struct tty_driver *sclp_tty_driver; |
| |
| static int sclp_tty_tolower; |
| static int sclp_tty_columns = 80; |
| |
| #define SPACES_PER_TAB 8 |
| #define CASE_DELIMITER 0x6c /* to separate upper and lower case (% in EBCDIC) */ |
| |
| /* This routine is called whenever we try to open a SCLP terminal. */ |
| static int |
| sclp_tty_open(struct tty_struct *tty, struct file *filp) |
| { |
| tty_port_tty_set(&sclp_port, tty); |
| tty->driver_data = NULL; |
| sclp_port.low_latency = 0; |
| return 0; |
| } |
| |
| /* This routine is called when the SCLP terminal is closed. */ |
| static void |
| sclp_tty_close(struct tty_struct *tty, struct file *filp) |
| { |
| if (tty->count > 1) |
| return; |
| tty_port_tty_set(&sclp_port, NULL); |
| } |
| |
| /* |
| * This routine returns the numbers of characters the tty driver |
| * will accept for queuing to be written. This number is subject |
| * to change as output buffers get emptied, or if the output flow |
| * control is acted. This is not an exact number because not every |
| * character needs the same space in the sccb. The worst case is |
| * a string of newlines. Every newlines creates a new mto which |
| * needs 8 bytes. |
| */ |
| static int |
| sclp_tty_write_room (struct tty_struct *tty) |
| { |
| unsigned long flags; |
| struct list_head *l; |
| int count; |
| |
| spin_lock_irqsave(&sclp_tty_lock, flags); |
| count = 0; |
| if (sclp_ttybuf != NULL) |
| count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct mto); |
| list_for_each(l, &sclp_tty_pages) |
| count += NR_EMPTY_MTO_PER_SCCB; |
| spin_unlock_irqrestore(&sclp_tty_lock, flags); |
| return count; |
| } |
| |
| static void |
| sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc) |
| { |
| struct tty_struct *tty; |
| unsigned long flags; |
| void *page; |
| |
| do { |
| page = sclp_unmake_buffer(buffer); |
| spin_lock_irqsave(&sclp_tty_lock, flags); |
| /* Remove buffer from outqueue */ |
| list_del(&buffer->list); |
| sclp_tty_buffer_count--; |
| list_add_tail((struct list_head *) page, &sclp_tty_pages); |
| /* Check if there is a pending buffer on the out queue. */ |
| buffer = NULL; |
| if (!list_empty(&sclp_tty_outqueue)) |
| buffer = list_entry(sclp_tty_outqueue.next, |
| struct sclp_buffer, list); |
| spin_unlock_irqrestore(&sclp_tty_lock, flags); |
| } while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback)); |
| /* check if the tty needs a wake up call */ |
| tty = tty_port_tty_get(&sclp_port); |
| if (tty != NULL) { |
| tty_wakeup(tty); |
| tty_kref_put(tty); |
| } |
| } |
| |
| static inline void |
| __sclp_ttybuf_emit(struct sclp_buffer *buffer) |
| { |
| unsigned long flags; |
| int count; |
| int rc; |
| |
| spin_lock_irqsave(&sclp_tty_lock, flags); |
| list_add_tail(&buffer->list, &sclp_tty_outqueue); |
| count = sclp_tty_buffer_count++; |
| spin_unlock_irqrestore(&sclp_tty_lock, flags); |
| if (count) |
| return; |
| rc = sclp_emit_buffer(buffer, sclp_ttybuf_callback); |
| if (rc) |
| sclp_ttybuf_callback(buffer, rc); |
| } |
| |
| /* |
| * When this routine is called from the timer then we flush the |
| * temporary write buffer. |
| */ |
| static void |
| sclp_tty_timeout(unsigned long data) |
| { |
| unsigned long flags; |
| struct sclp_buffer *buf; |
| |
| spin_lock_irqsave(&sclp_tty_lock, flags); |
| buf = sclp_ttybuf; |
| sclp_ttybuf = NULL; |
| spin_unlock_irqrestore(&sclp_tty_lock, flags); |
| |
| if (buf != NULL) { |
| __sclp_ttybuf_emit(buf); |
| } |
| } |
| |
| /* |
| * Write a string to the sclp tty. |
| */ |
| static int sclp_tty_write_string(const unsigned char *str, int count, int may_fail) |
| { |
| unsigned long flags; |
| void *page; |
| int written; |
| int overall_written; |
| struct sclp_buffer *buf; |
| |
| if (count <= 0) |
| return 0; |
| overall_written = 0; |
| spin_lock_irqsave(&sclp_tty_lock, flags); |
| do { |
| /* Create a sclp output buffer if none exists yet */ |
| if (sclp_ttybuf == NULL) { |
| while (list_empty(&sclp_tty_pages)) { |
| spin_unlock_irqrestore(&sclp_tty_lock, flags); |
| if (may_fail) |
| goto out; |
| else |
| sclp_sync_wait(); |
| spin_lock_irqsave(&sclp_tty_lock, flags); |
| } |
| page = sclp_tty_pages.next; |
| list_del((struct list_head *) page); |
| sclp_ttybuf = sclp_make_buffer(page, sclp_tty_columns, |
| SPACES_PER_TAB); |
| } |
| /* try to write the string to the current output buffer */ |
| written = sclp_write(sclp_ttybuf, str, count); |
| overall_written += written; |
| if (written == count) |
| break; |
| /* |
| * Not all characters could be written to the current |
| * output buffer. Emit the buffer, create a new buffer |
| * and then output the rest of the string. |
| */ |
| buf = sclp_ttybuf; |
| sclp_ttybuf = NULL; |
| spin_unlock_irqrestore(&sclp_tty_lock, flags); |
| __sclp_ttybuf_emit(buf); |
| spin_lock_irqsave(&sclp_tty_lock, flags); |
| str += written; |
| count -= written; |
| } while (count > 0); |
| /* Setup timer to output current console buffer after 1/10 second */ |
| if (sclp_ttybuf && sclp_chars_in_buffer(sclp_ttybuf) && |
| !timer_pending(&sclp_tty_timer)) { |
| init_timer(&sclp_tty_timer); |
| sclp_tty_timer.function = sclp_tty_timeout; |
| sclp_tty_timer.data = 0UL; |
| sclp_tty_timer.expires = jiffies + HZ/10; |
| add_timer(&sclp_tty_timer); |
| } |
| spin_unlock_irqrestore(&sclp_tty_lock, flags); |
| out: |
| return overall_written; |
| } |
| |
| /* |
| * This routine is called by the kernel to write a series of characters to the |
| * tty device. The characters may come from user space or kernel space. This |
| * routine will return the number of characters actually accepted for writing. |
| */ |
| static int |
| sclp_tty_write(struct tty_struct *tty, const unsigned char *buf, int count) |
| { |
| if (sclp_tty_chars_count > 0) { |
| sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0); |
| sclp_tty_chars_count = 0; |
| } |
| return sclp_tty_write_string(buf, count, 1); |
| } |
| |
| /* |
| * This routine is called by the kernel to write a single character to the tty |
| * device. If the kernel uses this routine, it must call the flush_chars() |
| * routine (if defined) when it is done stuffing characters into the driver. |
| * |
| * Characters provided to sclp_tty_put_char() are buffered by the SCLP driver. |
| * If the given character is a '\n' the contents of the SCLP write buffer |
| * - including previous characters from sclp_tty_put_char() and strings from |
| * sclp_write() without final '\n' - will be written. |
| */ |
| static int |
| sclp_tty_put_char(struct tty_struct *tty, unsigned char ch) |
| { |
| sclp_tty_chars[sclp_tty_chars_count++] = ch; |
| if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) { |
| sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0); |
| sclp_tty_chars_count = 0; |
| } |
| return 1; |
| } |
| |
| /* |
| * This routine is called by the kernel after it has written a series of |
| * characters to the tty device using put_char(). |
| */ |
| static void |
| sclp_tty_flush_chars(struct tty_struct *tty) |
| { |
| if (sclp_tty_chars_count > 0) { |
| sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0); |
| sclp_tty_chars_count = 0; |
| } |
| } |
| |
| /* |
| * This routine returns the number of characters in the write buffer of the |
| * SCLP driver. The provided number includes all characters that are stored |
| * in the SCCB (will be written next time the SCLP is not busy) as well as |
| * characters in the write buffer (will not be written as long as there is a |
| * final line feed missing). |
| */ |
| static int |
| sclp_tty_chars_in_buffer(struct tty_struct *tty) |
| { |
| unsigned long flags; |
| struct list_head *l; |
| struct sclp_buffer *t; |
| int count; |
| |
| spin_lock_irqsave(&sclp_tty_lock, flags); |
| count = 0; |
| if (sclp_ttybuf != NULL) |
| count = sclp_chars_in_buffer(sclp_ttybuf); |
| list_for_each(l, &sclp_tty_outqueue) { |
| t = list_entry(l, struct sclp_buffer, list); |
| count += sclp_chars_in_buffer(t); |
| } |
| spin_unlock_irqrestore(&sclp_tty_lock, flags); |
| return count; |
| } |
| |
| /* |
| * removes all content from buffers of low level driver |
| */ |
| static void |
| sclp_tty_flush_buffer(struct tty_struct *tty) |
| { |
| if (sclp_tty_chars_count > 0) { |
| sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0); |
| sclp_tty_chars_count = 0; |
| } |
| } |
| |
| /* |
| * push input to tty |
| */ |
| static void |
| sclp_tty_input(unsigned char* buf, unsigned int count) |
| { |
| struct tty_struct *tty = tty_port_tty_get(&sclp_port); |
| unsigned int cchar; |
| |
| /* |
| * If this tty driver is currently closed |
| * then throw the received input away. |
| */ |
| if (tty == NULL) |
| return; |
| cchar = ctrlchar_handle(buf, count, tty); |
| switch (cchar & CTRLCHAR_MASK) { |
| case CTRLCHAR_SYSRQ: |
| break; |
| case CTRLCHAR_CTRL: |
| tty_insert_flip_char(&sclp_port, cchar, TTY_NORMAL); |
| tty_flip_buffer_push(tty); |
| break; |
| case CTRLCHAR_NONE: |
| /* send (normal) input to line discipline */ |
| if (count < 2 || |
| (strncmp((const char *) buf + count - 2, "^n", 2) && |
| strncmp((const char *) buf + count - 2, "\252n", 2))) { |
| /* add the auto \n */ |
| tty_insert_flip_string(&sclp_port, buf, count); |
| tty_insert_flip_char(&sclp_port, '\n', TTY_NORMAL); |
| } else |
| tty_insert_flip_string(&sclp_port, buf, count - 2); |
| tty_flip_buffer_push(tty); |
| break; |
| } |
| tty_kref_put(tty); |
| } |
| |
| /* |
| * get a EBCDIC string in upper/lower case, |
| * find out characters in lower/upper case separated by a special character, |
| * modifiy original string, |
| * returns length of resulting string |
| */ |
| static int sclp_switch_cases(unsigned char *buf, int count) |
| { |
| unsigned char *ip, *op; |
| int toggle; |
| |
| /* initially changing case is off */ |
| toggle = 0; |
| ip = op = buf; |
| while (count-- > 0) { |
| /* compare with special character */ |
| if (*ip == CASE_DELIMITER) { |
| /* followed by another special character? */ |
| if (count && ip[1] == CASE_DELIMITER) { |
| /* |
| * ... then put a single copy of the special |
| * character to the output string |
| */ |
| *op++ = *ip++; |
| count--; |
| } else |
| /* |
| * ... special character follower by a normal |
| * character toggles the case change behaviour |
| */ |
| toggle = ~toggle; |
| /* skip special character */ |
| ip++; |
| } else |
| /* not the special character */ |
| if (toggle) |
| /* but case switching is on */ |
| if (sclp_tty_tolower) |
| /* switch to uppercase */ |
| *op++ = _ebc_toupper[(int) *ip++]; |
| else |
| /* switch to lowercase */ |
| *op++ = _ebc_tolower[(int) *ip++]; |
| else |
| /* no case switching, copy the character */ |
| *op++ = *ip++; |
| } |
| /* return length of reformatted string. */ |
| return op - buf; |
| } |
| |
| static void sclp_get_input(struct gds_subvector *sv) |
| { |
| unsigned char *str; |
| int count; |
| |
| str = (unsigned char *) (sv + 1); |
| count = sv->length - sizeof(*sv); |
| if (sclp_tty_tolower) |
| EBC_TOLOWER(str, count); |
| count = sclp_switch_cases(str, count); |
| /* convert EBCDIC to ASCII (modify original input in SCCB) */ |
| sclp_ebcasc_str(str, count); |
| |
| /* transfer input to high level driver */ |
| sclp_tty_input(str, count); |
| } |
| |
| static inline void sclp_eval_selfdeftextmsg(struct gds_subvector *sv) |
| { |
| void *end; |
| |
| end = (void *) sv + sv->length; |
| for (sv = sv + 1; (void *) sv < end; sv = (void *) sv + sv->length) |
| if (sv->key == 0x30) |
| sclp_get_input(sv); |
| } |
| |
| static inline void sclp_eval_textcmd(struct gds_vector *v) |
| { |
| struct gds_subvector *sv; |
| void *end; |
| |
| end = (void *) v + v->length; |
| for (sv = (struct gds_subvector *) (v + 1); |
| (void *) sv < end; sv = (void *) sv + sv->length) |
| if (sv->key == GDS_KEY_SELFDEFTEXTMSG) |
| sclp_eval_selfdeftextmsg(sv); |
| |
| } |
| |
| static inline void sclp_eval_cpmsu(struct gds_vector *v) |
| { |
| void *end; |
| |
| end = (void *) v + v->length; |
| for (v = v + 1; (void *) v < end; v = (void *) v + v->length) |
| if (v->gds_id == GDS_ID_TEXTCMD) |
| sclp_eval_textcmd(v); |
| } |
| |
| |
| static inline void sclp_eval_mdsmu(struct gds_vector *v) |
| { |
| v = sclp_find_gds_vector(v + 1, (void *) v + v->length, GDS_ID_CPMSU); |
| if (v) |
| sclp_eval_cpmsu(v); |
| } |
| |
| static void sclp_tty_receiver(struct evbuf_header *evbuf) |
| { |
| struct gds_vector *v; |
| |
| v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length, |
| GDS_ID_MDSMU); |
| if (v) |
| sclp_eval_mdsmu(v); |
| } |
| |
| static void |
| sclp_tty_state_change(struct sclp_register *reg) |
| { |
| } |
| |
| static struct sclp_register sclp_input_event = |
| { |
| .receive_mask = EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK, |
| .state_change_fn = sclp_tty_state_change, |
| .receiver_fn = sclp_tty_receiver |
| }; |
| |
| static const struct tty_operations sclp_ops = { |
| .open = sclp_tty_open, |
| .close = sclp_tty_close, |
| .write = sclp_tty_write, |
| .put_char = sclp_tty_put_char, |
| .flush_chars = sclp_tty_flush_chars, |
| .write_room = sclp_tty_write_room, |
| .chars_in_buffer = sclp_tty_chars_in_buffer, |
| .flush_buffer = sclp_tty_flush_buffer, |
| }; |
| |
| static int __init |
| sclp_tty_init(void) |
| { |
| struct tty_driver *driver; |
| void *page; |
| int i; |
| int rc; |
| |
| if (!CONSOLE_IS_SCLP) |
| return 0; |
| driver = alloc_tty_driver(1); |
| if (!driver) |
| return -ENOMEM; |
| |
| rc = sclp_rw_init(); |
| if (rc) { |
| put_tty_driver(driver); |
| return rc; |
| } |
| /* Allocate pages for output buffering */ |
| INIT_LIST_HEAD(&sclp_tty_pages); |
| for (i = 0; i < MAX_KMEM_PAGES; i++) { |
| page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); |
| if (page == NULL) { |
| put_tty_driver(driver); |
| return -ENOMEM; |
| } |
| list_add_tail((struct list_head *) page, &sclp_tty_pages); |
| } |
| INIT_LIST_HEAD(&sclp_tty_outqueue); |
| spin_lock_init(&sclp_tty_lock); |
| init_timer(&sclp_tty_timer); |
| sclp_ttybuf = NULL; |
| sclp_tty_buffer_count = 0; |
| if (MACHINE_IS_VM) { |
| /* |
| * save 4 characters for the CPU number |
| * written at start of each line by VM/CP |
| */ |
| sclp_tty_columns = 76; |
| /* case input lines to lowercase */ |
| sclp_tty_tolower = 1; |
| } |
| sclp_tty_chars_count = 0; |
| |
| rc = sclp_register(&sclp_input_event); |
| if (rc) { |
| put_tty_driver(driver); |
| return rc; |
| } |
| |
| tty_port_init(&sclp_port); |
| |
| driver->driver_name = "sclp_line"; |
| driver->name = "sclp_line"; |
| driver->major = TTY_MAJOR; |
| driver->minor_start = 64; |
| driver->type = TTY_DRIVER_TYPE_SYSTEM; |
| driver->subtype = SYSTEM_TYPE_TTY; |
| driver->init_termios = tty_std_termios; |
| driver->init_termios.c_iflag = IGNBRK | IGNPAR; |
| driver->init_termios.c_oflag = ONLCR | XTABS; |
| driver->init_termios.c_lflag = ISIG | ECHO; |
| driver->flags = TTY_DRIVER_REAL_RAW; |
| tty_set_operations(driver, &sclp_ops); |
| tty_port_link_device(&sclp_port, driver, 0); |
| rc = tty_register_driver(driver); |
| if (rc) { |
| put_tty_driver(driver); |
| tty_port_destroy(&sclp_port); |
| return rc; |
| } |
| sclp_tty_driver = driver; |
| return 0; |
| } |
| module_init(sclp_tty_init); |