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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/s390/char/sclp_con.c
downloadop-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
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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.c252
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 0000000..10ef22f
--- /dev/null
+++ b/drivers/s390/char/sclp_con.c
@@ -0,0 +1,252 @@
+/*
+ * drivers/s390/char/sclp_con.c
+ * SCLP line mode console driver
+ *
+ * S390 version
+ * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Author(s): Martin Peschke <mpeschke@de.ibm.com>
+ * Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/config.h>
+#include <linux/kmod.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+#include <linux/bootmem.h>
+#include <linux/err.h>
+
+#include "sclp.h"
+#include "sclp_rw.h"
+#include "sclp_tty.h"
+
+#define SCLP_CON_PRINT_HEADER "sclp console driver: "
+
+#define sclp_console_major 4 /* TTYAUX_MAJOR */
+#define sclp_console_minor 64
+#define sclp_console_name "ttyS"
+
+/* Lock to guard over changes to global variables */
+static spinlock_t sclp_con_lock;
+/* List of free pages that can be used for console output buffering */
+static struct list_head sclp_con_pages;
+/* List of full struct sclp_buffer structures ready for output */
+static struct list_head sclp_con_outqueue;
+/* Counter how many buffers are emitted (max 1) and how many */
+/* are on the output queue. */
+static int sclp_con_buffer_count;
+/* Pointer to current console buffer */
+static struct sclp_buffer *sclp_conbuf;
+/* Timer for delayed output of console messages */
+static struct timer_list sclp_con_timer;
+
+/* Output format for console messages */
+static unsigned short sclp_con_columns;
+static unsigned short sclp_con_width_htab;
+
+static void
+sclp_conbuf_callback(struct sclp_buffer *buffer, int rc)
+{
+ unsigned long flags;
+ void *page;
+
+ do {
+ page = sclp_unmake_buffer(buffer);
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ /* Remove buffer from outqueue */
+ list_del(&buffer->list);
+ sclp_con_buffer_count--;
+ list_add_tail((struct list_head *) page, &sclp_con_pages);
+ /* Check if there is a pending buffer on the out queue. */
+ buffer = NULL;
+ if (!list_empty(&sclp_con_outqueue))
+ buffer = list_entry(sclp_con_outqueue.next,
+ struct sclp_buffer, list);
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+ } while (buffer && sclp_emit_buffer(buffer, sclp_conbuf_callback));
+}
+
+static inline void
+sclp_conbuf_emit(void)
+{
+ struct sclp_buffer* buffer;
+ unsigned long flags;
+ int count;
+ int rc;
+
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ buffer = sclp_conbuf;
+ sclp_conbuf = NULL;
+ if (buffer == NULL) {
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+ return;
+ }
+ list_add_tail(&buffer->list, &sclp_con_outqueue);
+ count = sclp_con_buffer_count++;
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+ if (count)
+ return;
+ rc = sclp_emit_buffer(buffer, sclp_conbuf_callback);
+ if (rc)
+ sclp_conbuf_callback(buffer, rc);
+}
+
+/*
+ * When this routine is called from the timer then we flush the
+ * temporary write buffer without further waiting on a final new line.
+ */
+static void
+sclp_console_timeout(unsigned long data)
+{
+ sclp_conbuf_emit();
+}
+
+/*
+ * Writes the given message to S390 system console
+ */
+static void
+sclp_console_write(struct console *console, const char *message,
+ unsigned int count)
+{
+ unsigned long flags;
+ void *page;
+ int written;
+
+ if (count == 0)
+ return;
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ /*
+ * process escape characters, write message into buffer,
+ * send buffer to SCLP
+ */
+ do {
+ /* make sure we have a console output buffer */
+ if (sclp_conbuf == NULL) {
+ while (list_empty(&sclp_con_pages)) {
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+ sclp_sync_wait();
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ }
+ page = sclp_con_pages.next;
+ list_del((struct list_head *) page);
+ sclp_conbuf = sclp_make_buffer(page, sclp_con_columns,
+ sclp_con_width_htab);
+ }
+ /* try to write the string to the current output buffer */
+ written = sclp_write(sclp_conbuf, (const unsigned char *)
+ message, count);
+ 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_con_lock, flags);
+ sclp_conbuf_emit();
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ message += written;
+ count -= written;
+ } while (count > 0);
+ /* Setup timer to output current console buffer after 1/10 second */
+ if (sclp_conbuf != NULL && sclp_chars_in_buffer(sclp_conbuf) != 0 &&
+ !timer_pending(&sclp_con_timer)) {
+ init_timer(&sclp_con_timer);
+ sclp_con_timer.function = sclp_console_timeout;
+ sclp_con_timer.data = 0UL;
+ sclp_con_timer.expires = jiffies + HZ/10;
+ add_timer(&sclp_con_timer);
+ }
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+}
+
+static struct tty_driver *
+sclp_console_device(struct console *c, int *index)
+{
+ *index = c->index;
+ return sclp_tty_driver;
+}
+
+/*
+ * This routine is called from panic when the kernel
+ * is going to give up. We have to make sure that all buffers
+ * will be flushed to the SCLP.
+ */
+static void
+sclp_console_unblank(void)
+{
+ unsigned long flags;
+
+ sclp_conbuf_emit();
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ if (timer_pending(&sclp_con_timer))
+ del_timer(&sclp_con_timer);
+ while (sclp_con_buffer_count > 0) {
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+ sclp_sync_wait();
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ }
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+}
+
+/*
+ * used to register the SCLP console to the kernel and to
+ * give printk necessary information
+ */
+static struct console sclp_console =
+{
+ .name = sclp_console_name,
+ .write = sclp_console_write,
+ .device = sclp_console_device,
+ .unblank = sclp_console_unblank,
+ .flags = CON_PRINTBUFFER,
+ .index = 0 /* ttyS0 */
+};
+
+/*
+ * called by console_init() in drivers/char/tty_io.c at boot-time.
+ */
+static int __init
+sclp_console_init(void)
+{
+ void *page;
+ int i;
+ int rc;
+
+ if (!CONSOLE_IS_SCLP)
+ return 0;
+ rc = sclp_rw_init();
+ if (rc)
+ return rc;
+ /* Allocate pages for output buffering */
+ INIT_LIST_HEAD(&sclp_con_pages);
+ for (i = 0; i < MAX_CONSOLE_PAGES; i++) {
+ page = alloc_bootmem_low_pages(PAGE_SIZE);
+ if (page == NULL)
+ return -ENOMEM;
+ list_add_tail((struct list_head *) page, &sclp_con_pages);
+ }
+ INIT_LIST_HEAD(&sclp_con_outqueue);
+ spin_lock_init(&sclp_con_lock);
+ sclp_con_buffer_count = 0;
+ sclp_conbuf = NULL;
+ init_timer(&sclp_con_timer);
+
+ /* Set output format */
+ if (MACHINE_IS_VM)
+ /*
+ * save 4 characters for the CPU number
+ * written at start of each line by VM/CP
+ */
+ sclp_con_columns = 76;
+ else
+ sclp_con_columns = 80;
+ sclp_con_width_htab = 8;
+
+ /* enable printk-access to this driver */
+ register_console(&sclp_console);
+ return 0;
+}
+
+console_initcall(sclp_console_init);
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