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Diffstat (limited to '')
| -rw-r--r-- | drivers/s390/char/sclp_vt220.c | 898 |
1 files changed, 898 insertions, 0 deletions
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c new file mode 100644 index 000000000..3c2ed6d01 --- /dev/null +++ b/drivers/s390/char/sclp_vt220.c @@ -0,0 +1,898 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SCLP VT220 terminal driver. + * + * Copyright IBM Corp. 2003, 2009 + * + * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com> + */ + +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/list.h> +#include <linux/wait.h> +#include <linux/timer.h> +#include <linux/kernel.h> +#include <linux/sysrq.h> +#include <linux/tty.h> +#include <linux/tty_driver.h> +#include <linux/tty_flip.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/major.h> +#include <linux/console.h> +#include <linux/kdev_t.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/reboot.h> +#include <linux/slab.h> + +#include <linux/uaccess.h> +#include "sclp.h" +#include "ctrlchar.h" + +#define SCLP_VT220_MAJOR TTY_MAJOR +#define SCLP_VT220_MINOR 65 +#define SCLP_VT220_DRIVER_NAME "sclp_vt220" +#define SCLP_VT220_DEVICE_NAME "ttysclp" +#define SCLP_VT220_CONSOLE_NAME "ttysclp" +#define SCLP_VT220_CONSOLE_INDEX 0 /* console=ttysclp0 */ + +/* Representation of a single write request */ +struct sclp_vt220_request { + struct list_head list; + struct sclp_req sclp_req; + int retry_count; +}; + +/* VT220 SCCB */ +struct sclp_vt220_sccb { + struct sccb_header header; + struct evbuf_header evbuf; +}; + +#define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \ + sizeof(struct sclp_vt220_request) - \ + sizeof(struct sclp_vt220_sccb)) + +/* Structures and data needed to register tty driver */ +static struct tty_driver *sclp_vt220_driver; + +static struct tty_port sclp_vt220_port; + +/* Lock to protect internal data from concurrent access */ +static spinlock_t sclp_vt220_lock; + +/* List of empty pages to be used as write request buffers */ +static struct list_head sclp_vt220_empty; + +/* List of pending requests */ +static struct list_head sclp_vt220_outqueue; + +/* Suspend mode flag */ +static int sclp_vt220_suspended; + +/* Flag that output queue is currently running */ +static int sclp_vt220_queue_running; + +/* Timer used for delaying write requests to merge subsequent messages into + * a single buffer */ +static struct timer_list sclp_vt220_timer; + +/* Pointer to current request buffer which has been partially filled but not + * yet sent */ +static struct sclp_vt220_request *sclp_vt220_current_request; + +/* Number of characters in current request buffer */ +static int sclp_vt220_buffered_chars; + +/* Counter controlling core driver initialization. */ +static int __initdata sclp_vt220_init_count; + +/* Flag indicating that sclp_vt220_current_request should really + * have been already queued but wasn't because the SCLP was processing + * another buffer */ +static int sclp_vt220_flush_later; + +static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); +static void sclp_vt220_pm_event_fn(struct sclp_register *reg, + enum sclp_pm_event sclp_pm_event); +static int __sclp_vt220_emit(struct sclp_vt220_request *request); +static void sclp_vt220_emit_current(void); + +/* Registration structure for SCLP output event buffers */ +static struct sclp_register sclp_vt220_register = { + .send_mask = EVTYP_VT220MSG_MASK, + .pm_event_fn = sclp_vt220_pm_event_fn, +}; + +/* Registration structure for SCLP input event buffers */ +static struct sclp_register sclp_vt220_register_input = { + .receive_mask = EVTYP_VT220MSG_MASK, + .receiver_fn = sclp_vt220_receiver_fn, +}; + + +/* + * Put provided request buffer back into queue and check emit pending + * buffers if necessary. + */ +static void +sclp_vt220_process_queue(struct sclp_vt220_request *request) +{ + unsigned long flags; + void *page; + + do { + /* Put buffer back to list of empty buffers */ + page = request->sclp_req.sccb; + spin_lock_irqsave(&sclp_vt220_lock, flags); + /* Move request from outqueue to empty queue */ + list_del(&request->list); + list_add_tail((struct list_head *) page, &sclp_vt220_empty); + /* Check if there is a pending buffer on the out queue. */ + request = NULL; + if (!list_empty(&sclp_vt220_outqueue)) + request = list_entry(sclp_vt220_outqueue.next, + struct sclp_vt220_request, list); + if (!request || sclp_vt220_suspended) { + sclp_vt220_queue_running = 0; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + break; + } + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + } while (__sclp_vt220_emit(request)); + if (request == NULL && sclp_vt220_flush_later) + sclp_vt220_emit_current(); + tty_port_tty_wakeup(&sclp_vt220_port); +} + +#define SCLP_BUFFER_MAX_RETRY 1 + +/* + * Callback through which the result of a write request is reported by the + * SCLP. + */ +static void +sclp_vt220_callback(struct sclp_req *request, void *data) +{ + struct sclp_vt220_request *vt220_request; + struct sclp_vt220_sccb *sccb; + + vt220_request = (struct sclp_vt220_request *) data; + if (request->status == SCLP_REQ_FAILED) { + sclp_vt220_process_queue(vt220_request); + return; + } + sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; + + /* Check SCLP response code and choose suitable action */ + switch (sccb->header.response_code) { + case 0x0020 : + break; + + case 0x05f0: /* Target resource in improper state */ + break; + + case 0x0340: /* Contained SCLP equipment check */ + if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) + break; + /* Remove processed buffers and requeue rest */ + if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { + /* Not all buffers were processed */ + sccb->header.response_code = 0x0000; + vt220_request->sclp_req.status = SCLP_REQ_FILLED; + if (sclp_add_request(request) == 0) + return; + } + break; + + case 0x0040: /* SCLP equipment check */ + if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) + break; + sccb->header.response_code = 0x0000; + vt220_request->sclp_req.status = SCLP_REQ_FILLED; + if (sclp_add_request(request) == 0) + return; + break; + + default: + break; + } + sclp_vt220_process_queue(vt220_request); +} + +/* + * Emit vt220 request buffer to SCLP. Return zero on success, non-zero + * otherwise. + */ +static int +__sclp_vt220_emit(struct sclp_vt220_request *request) +{ + request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA; + request->sclp_req.status = SCLP_REQ_FILLED; + request->sclp_req.callback = sclp_vt220_callback; + request->sclp_req.callback_data = (void *) request; + + return sclp_add_request(&request->sclp_req); +} + +/* + * Queue and emit current request. + */ +static void +sclp_vt220_emit_current(void) +{ + unsigned long flags; + struct sclp_vt220_request *request; + struct sclp_vt220_sccb *sccb; + + spin_lock_irqsave(&sclp_vt220_lock, flags); + if (sclp_vt220_current_request) { + sccb = (struct sclp_vt220_sccb *) + sclp_vt220_current_request->sclp_req.sccb; + /* Only emit buffers with content */ + if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { + list_add_tail(&sclp_vt220_current_request->list, + &sclp_vt220_outqueue); + sclp_vt220_current_request = NULL; + if (timer_pending(&sclp_vt220_timer)) + del_timer(&sclp_vt220_timer); + } + sclp_vt220_flush_later = 0; + } + if (sclp_vt220_queue_running || sclp_vt220_suspended) + goto out_unlock; + if (list_empty(&sclp_vt220_outqueue)) + goto out_unlock; + request = list_first_entry(&sclp_vt220_outqueue, + struct sclp_vt220_request, list); + sclp_vt220_queue_running = 1; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + + if (__sclp_vt220_emit(request)) + sclp_vt220_process_queue(request); + return; +out_unlock: + spin_unlock_irqrestore(&sclp_vt220_lock, flags); +} + +#define SCLP_NORMAL_WRITE 0x00 + +/* + * Helper function to initialize a page with the sclp request structure. + */ +static struct sclp_vt220_request * +sclp_vt220_initialize_page(void *page) +{ + struct sclp_vt220_request *request; + struct sclp_vt220_sccb *sccb; + + /* Place request structure at end of page */ + request = ((struct sclp_vt220_request *) + ((addr_t) page + PAGE_SIZE)) - 1; + request->retry_count = 0; + request->sclp_req.sccb = page; + /* SCCB goes at start of page */ + sccb = (struct sclp_vt220_sccb *) page; + memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb)); + sccb->header.length = sizeof(struct sclp_vt220_sccb); + sccb->header.function_code = SCLP_NORMAL_WRITE; + sccb->header.response_code = 0x0000; + sccb->evbuf.type = EVTYP_VT220MSG; + sccb->evbuf.length = sizeof(struct evbuf_header); + + return request; +} + +static inline unsigned int +sclp_vt220_space_left(struct sclp_vt220_request *request) +{ + struct sclp_vt220_sccb *sccb; + sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; + return PAGE_SIZE - sizeof(struct sclp_vt220_request) - + sccb->header.length; +} + +static inline unsigned int +sclp_vt220_chars_stored(struct sclp_vt220_request *request) +{ + struct sclp_vt220_sccb *sccb; + sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; + return sccb->evbuf.length - sizeof(struct evbuf_header); +} + +/* + * Add msg to buffer associated with request. Return the number of characters + * added. + */ +static int +sclp_vt220_add_msg(struct sclp_vt220_request *request, + const unsigned char *msg, int count, int convertlf) +{ + struct sclp_vt220_sccb *sccb; + void *buffer; + unsigned char c; + int from; + int to; + + if (count > sclp_vt220_space_left(request)) + count = sclp_vt220_space_left(request); + if (count <= 0) + return 0; + + sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; + buffer = (void *) ((addr_t) sccb + sccb->header.length); + + if (convertlf) { + /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/ + for (from=0, to=0; + (from < count) && (to < sclp_vt220_space_left(request)); + from++) { + /* Retrieve character */ + c = msg[from]; + /* Perform conversion */ + if (c == 0x0a) { + if (to + 1 < sclp_vt220_space_left(request)) { + ((unsigned char *) buffer)[to++] = c; + ((unsigned char *) buffer)[to++] = 0x0d; + } else + break; + + } else + ((unsigned char *) buffer)[to++] = c; + } + sccb->header.length += to; + sccb->evbuf.length += to; + return from; + } else { + memcpy(buffer, (const void *) msg, count); + sccb->header.length += count; + sccb->evbuf.length += count; + return count; + } +} + +/* + * Emit buffer after having waited long enough for more data to arrive. + */ +static void +sclp_vt220_timeout(struct timer_list *unused) +{ + sclp_vt220_emit_current(); +} + +#define BUFFER_MAX_DELAY HZ/20 + +/* + * Drop oldest console buffer if sclp_con_drop is set + */ +static int +sclp_vt220_drop_buffer(void) +{ + struct list_head *list; + struct sclp_vt220_request *request; + void *page; + + if (!sclp_console_drop) + return 0; + list = sclp_vt220_outqueue.next; + if (sclp_vt220_queue_running) + /* The first element is in I/O */ + list = list->next; + if (list == &sclp_vt220_outqueue) + return 0; + list_del(list); + request = list_entry(list, struct sclp_vt220_request, list); + page = request->sclp_req.sccb; + list_add_tail((struct list_head *) page, &sclp_vt220_empty); + return 1; +} + +/* + * Internal implementation of the write function. Write COUNT bytes of data + * from memory at BUF + * to the SCLP interface. In case that the data does not fit into the current + * write buffer, emit the current one and allocate a new one. If there are no + * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE + * is non-zero, the buffer will be scheduled for emitting after a timeout - + * otherwise the user has to explicitly call the flush function. + * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message + * buffer should be converted to 0x0a 0x0d. After completion, return the number + * of bytes written. + */ +static int +__sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, + int convertlf, int may_fail) +{ + unsigned long flags; + void *page; + int written; + int overall_written; + + if (count <= 0) + return 0; + overall_written = 0; + spin_lock_irqsave(&sclp_vt220_lock, flags); + do { + /* Create an sclp output buffer if none exists yet */ + if (sclp_vt220_current_request == NULL) { + if (list_empty(&sclp_vt220_empty)) + sclp_console_full++; + while (list_empty(&sclp_vt220_empty)) { + if (may_fail || sclp_vt220_suspended) + goto out; + if (sclp_vt220_drop_buffer()) + break; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + + sclp_sync_wait(); + spin_lock_irqsave(&sclp_vt220_lock, flags); + } + page = (void *) sclp_vt220_empty.next; + list_del((struct list_head *) page); + sclp_vt220_current_request = + sclp_vt220_initialize_page(page); + } + /* Try to write the string to the current request buffer */ + written = sclp_vt220_add_msg(sclp_vt220_current_request, + buf, count, convertlf); + 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. + */ + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + sclp_vt220_emit_current(); + spin_lock_irqsave(&sclp_vt220_lock, flags); + buf += written; + count -= written; + } while (count > 0); + /* Setup timer to output current console buffer after some time */ + if (sclp_vt220_current_request != NULL && + !timer_pending(&sclp_vt220_timer) && do_schedule) { + sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; + add_timer(&sclp_vt220_timer); + } +out: + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + 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_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) +{ + return __sclp_vt220_write(buf, count, 1, 0, 1); +} + +#define SCLP_VT220_SESSION_ENDED 0x01 +#define SCLP_VT220_SESSION_STARTED 0x80 +#define SCLP_VT220_SESSION_DATA 0x00 + +#ifdef CONFIG_MAGIC_SYSRQ + +static int sysrq_pressed; +static struct sysrq_work sysrq; + +static void sclp_vt220_reset_session(void) +{ + sysrq_pressed = 0; +} + +static void sclp_vt220_handle_input(const char *buffer, unsigned int count) +{ + int i; + + for (i = 0; i < count; i++) { + /* Handle magic sys request */ + if (buffer[i] == ('O' ^ 0100)) { /* CTRL-O */ + /* + * If pressed again, reset sysrq_pressed + * and flip CTRL-O character + */ + sysrq_pressed = !sysrq_pressed; + if (sysrq_pressed) + continue; + } else if (sysrq_pressed) { + sysrq.key = buffer[i]; + schedule_sysrq_work(&sysrq); + sysrq_pressed = 0; + continue; + } + tty_insert_flip_char(&sclp_vt220_port, buffer[i], 0); + } +} + +#else + +static void sclp_vt220_reset_session(void) +{ +} + +static void sclp_vt220_handle_input(const char *buffer, unsigned int count) +{ + tty_insert_flip_string(&sclp_vt220_port, buffer, count); +} + +#endif + +/* + * Called by the SCLP to report incoming event buffers. + */ +static void +sclp_vt220_receiver_fn(struct evbuf_header *evbuf) +{ + char *buffer; + unsigned int count; + + buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); + count = evbuf->length - sizeof(struct evbuf_header); + + switch (*buffer) { + case SCLP_VT220_SESSION_ENDED: + case SCLP_VT220_SESSION_STARTED: + sclp_vt220_reset_session(); + break; + case SCLP_VT220_SESSION_DATA: + /* Send input to line discipline */ + buffer++; + count--; + sclp_vt220_handle_input(buffer, count); + tty_flip_buffer_push(&sclp_vt220_port); + break; + } +} + +/* + * This routine is called when a particular tty device is opened. + */ +static int +sclp_vt220_open(struct tty_struct *tty, struct file *filp) +{ + if (tty->count == 1) { + tty_port_tty_set(&sclp_vt220_port, tty); + sclp_vt220_port.low_latency = 0; + if (!tty->winsize.ws_row && !tty->winsize.ws_col) { + tty->winsize.ws_row = 24; + tty->winsize.ws_col = 80; + } + } + return 0; +} + +/* + * This routine is called when a particular tty device is closed. + */ +static void +sclp_vt220_close(struct tty_struct *tty, struct file *filp) +{ + if (tty->count == 1) + tty_port_tty_set(&sclp_vt220_port, NULL); +} + +/* + * 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. + */ +static int +sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) +{ + return __sclp_vt220_write(&ch, 1, 0, 0, 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_vt220_flush_chars(struct tty_struct *tty) +{ + if (!sclp_vt220_queue_running) + sclp_vt220_emit_current(); + else + sclp_vt220_flush_later = 1; +} + +/* + * 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. + */ +static int +sclp_vt220_write_room(struct tty_struct *tty) +{ + unsigned long flags; + struct list_head *l; + int count; + + spin_lock_irqsave(&sclp_vt220_lock, flags); + count = 0; + if (sclp_vt220_current_request != NULL) + count = sclp_vt220_space_left(sclp_vt220_current_request); + list_for_each(l, &sclp_vt220_empty) + count += SCLP_VT220_MAX_CHARS_PER_BUFFER; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + return count; +} + +/* + * Return number of buffered chars. + */ +static int +sclp_vt220_chars_in_buffer(struct tty_struct *tty) +{ + unsigned long flags; + struct list_head *l; + struct sclp_vt220_request *r; + int count; + + spin_lock_irqsave(&sclp_vt220_lock, flags); + count = 0; + if (sclp_vt220_current_request != NULL) + count = sclp_vt220_chars_stored(sclp_vt220_current_request); + list_for_each(l, &sclp_vt220_outqueue) { + r = list_entry(l, struct sclp_vt220_request, list); + count += sclp_vt220_chars_stored(r); + } + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + return count; +} + +/* + * Pass on all buffers to the hardware. Return only when there are no more + * buffers pending. + */ +static void +sclp_vt220_flush_buffer(struct tty_struct *tty) +{ + sclp_vt220_emit_current(); +} + +/* Release allocated pages. */ +static void __init __sclp_vt220_free_pages(void) +{ + struct list_head *page, *p; + + list_for_each_safe(page, p, &sclp_vt220_empty) { + list_del(page); + free_page((unsigned long) page); + } +} + +/* Release memory and unregister from sclp core. Controlled by init counting - + * only the last invoker will actually perform these actions. */ +static void __init __sclp_vt220_cleanup(void) +{ + sclp_vt220_init_count--; + if (sclp_vt220_init_count != 0) + return; + sclp_unregister(&sclp_vt220_register); + __sclp_vt220_free_pages(); + tty_port_destroy(&sclp_vt220_port); +} + +/* Allocate buffer pages and register with sclp core. Controlled by init + * counting - only the first invoker will actually perform these actions. */ +static int __init __sclp_vt220_init(int num_pages) +{ + void *page; + int i; + int rc; + + sclp_vt220_init_count++; + if (sclp_vt220_init_count != 1) + return 0; + spin_lock_init(&sclp_vt220_lock); + INIT_LIST_HEAD(&sclp_vt220_empty); + INIT_LIST_HEAD(&sclp_vt220_outqueue); + timer_setup(&sclp_vt220_timer, sclp_vt220_timeout, 0); + tty_port_init(&sclp_vt220_port); + sclp_vt220_current_request = NULL; + sclp_vt220_buffered_chars = 0; + sclp_vt220_flush_later = 0; + + /* Allocate pages for output buffering */ + rc = -ENOMEM; + for (i = 0; i < num_pages; i++) { + page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); + if (!page) + goto out; + list_add_tail(page, &sclp_vt220_empty); + } + rc = sclp_register(&sclp_vt220_register); +out: + if (rc) { + __sclp_vt220_free_pages(); + sclp_vt220_init_count--; + tty_port_destroy(&sclp_vt220_port); + } + return rc; +} + +static const struct tty_operations sclp_vt220_ops = { + .open = sclp_vt220_open, + .close = sclp_vt220_close, + .write = sclp_vt220_write, + .put_char = sclp_vt220_put_char, + .flush_chars = sclp_vt220_flush_chars, + .write_room = sclp_vt220_write_room, + .chars_in_buffer = sclp_vt220_chars_in_buffer, + .flush_buffer = sclp_vt220_flush_buffer, +}; + +/* + * Register driver with SCLP and Linux and initialize internal tty structures. + */ +static int __init sclp_vt220_tty_init(void) +{ + struct tty_driver *driver; + int rc; + + /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve + * symmetry between VM and LPAR systems regarding ttyS1. */ + driver = alloc_tty_driver(1); + if (!driver) + return -ENOMEM; + rc = __sclp_vt220_init(MAX_KMEM_PAGES); + if (rc) + goto out_driver; + + driver->driver_name = SCLP_VT220_DRIVER_NAME; + driver->name = SCLP_VT220_DEVICE_NAME; + driver->major = SCLP_VT220_MAJOR; + driver->minor_start = SCLP_VT220_MINOR; + driver->type = TTY_DRIVER_TYPE_SYSTEM; + driver->subtype = SYSTEM_TYPE_TTY; + driver->init_termios = tty_std_termios; + driver->flags = TTY_DRIVER_REAL_RAW; + tty_set_operations(driver, &sclp_vt220_ops); + tty_port_link_device(&sclp_vt220_port, driver, 0); + + rc = tty_register_driver(driver); + if (rc) + goto out_init; + rc = sclp_register(&sclp_vt220_register_input); + if (rc) + goto out_reg; + sclp_vt220_driver = driver; + return 0; + +out_reg: + tty_unregister_driver(driver); +out_init: + __sclp_vt220_cleanup(); +out_driver: + put_tty_driver(driver); + return rc; +} +__initcall(sclp_vt220_tty_init); + +static void __sclp_vt220_flush_buffer(void) +{ + unsigned long flags; + + sclp_vt220_emit_current(); + spin_lock_irqsave(&sclp_vt220_lock, flags); + if (timer_pending(&sclp_vt220_timer)) + del_timer(&sclp_vt220_timer); + while (sclp_vt220_queue_running) { + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + sclp_sync_wait(); + spin_lock_irqsave(&sclp_vt220_lock, flags); + } + spin_unlock_irqrestore(&sclp_vt220_lock, flags); +} + +/* + * Resume console: If there are cached messages, emit them. + */ +static void sclp_vt220_resume(void) +{ + unsigned long flags; + + spin_lock_irqsave(&sclp_vt220_lock, flags); + sclp_vt220_suspended = 0; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + sclp_vt220_emit_current(); +} + +/* + * Suspend console: Set suspend flag and flush console + */ +static void sclp_vt220_suspend(void) +{ + unsigned long flags; + + spin_lock_irqsave(&sclp_vt220_lock, flags); + sclp_vt220_suspended = 1; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + __sclp_vt220_flush_buffer(); +} + +static void sclp_vt220_pm_event_fn(struct sclp_register *reg, + enum sclp_pm_event sclp_pm_event) +{ + switch (sclp_pm_event) { + case SCLP_PM_EVENT_FREEZE: + sclp_vt220_suspend(); + break; + case SCLP_PM_EVENT_RESTORE: + case SCLP_PM_EVENT_THAW: + sclp_vt220_resume(); + break; + } +} + +#ifdef CONFIG_SCLP_VT220_CONSOLE + +static void +sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) +{ + __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0); +} + +static struct tty_driver * +sclp_vt220_con_device(struct console *c, int *index) +{ + *index = 0; + return sclp_vt220_driver; +} + +static int +sclp_vt220_notify(struct notifier_block *self, + unsigned long event, void *data) +{ + __sclp_vt220_flush_buffer(); + return NOTIFY_OK; +} + +static struct notifier_block on_panic_nb = { + .notifier_call = sclp_vt220_notify, + .priority = 1, +}; + +static struct notifier_block on_reboot_nb = { + .notifier_call = sclp_vt220_notify, + .priority = 1, +}; + +/* Structure needed to register with printk */ +static struct console sclp_vt220_console = +{ + .name = SCLP_VT220_CONSOLE_NAME, + .write = sclp_vt220_con_write, + .device = sclp_vt220_con_device, + .flags = CON_PRINTBUFFER, + .index = SCLP_VT220_CONSOLE_INDEX +}; + +static int __init +sclp_vt220_con_init(void) +{ + int rc; + + rc = __sclp_vt220_init(sclp_console_pages); + if (rc) + return rc; + /* Attach linux console */ + atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb); + register_reboot_notifier(&on_reboot_nb); + register_console(&sclp_vt220_console); + return 0; +} + +console_initcall(sclp_vt220_con_init); +#endif /* CONFIG_SCLP_VT220_CONSOLE */ + |