+/*
+ * limited & delayed printing support for MCA/INIT handler
+ */
+
+#define mprintk(fmt...) ia64_mca_printk(fmt)
+
+#define MLOGBUF_SIZE (512+256*NR_CPUS)
+#define MLOGBUF_MSGMAX 256
+static char mlogbuf[MLOGBUF_SIZE];
+static DEFINE_SPINLOCK(mlogbuf_wlock); /* mca context only */
+static DEFINE_SPINLOCK(mlogbuf_rlock); /* normal context only */
+static unsigned long mlogbuf_start;
+static unsigned long mlogbuf_end;
+static unsigned int mlogbuf_finished = 0;
+static unsigned long mlogbuf_timestamp = 0;
+
+static int loglevel_save = -1;
+#define BREAK_LOGLEVEL(__console_loglevel) \
+ oops_in_progress = 1; \
+ if (loglevel_save < 0) \
+ loglevel_save = __console_loglevel; \
+ __console_loglevel = 15;
+
+#define RESTORE_LOGLEVEL(__console_loglevel) \
+ if (loglevel_save >= 0) { \
+ __console_loglevel = loglevel_save; \
+ loglevel_save = -1; \
+ } \
+ mlogbuf_finished = 0; \
+ oops_in_progress = 0;
+
+/*
+ * Push messages into buffer, print them later if not urgent.
+ */
+void ia64_mca_printk(const char *fmt, ...)
+{
+ va_list args;
+ int printed_len;
+ char temp_buf[MLOGBUF_MSGMAX];
+ char *p;
+
+ va_start(args, fmt);
+ printed_len = vscnprintf(temp_buf, sizeof(temp_buf), fmt, args);
+ va_end(args);
+
+ /* Copy the output into mlogbuf */
+ if (oops_in_progress) {
+ /* mlogbuf was abandoned, use printk directly instead. */
+ printk(temp_buf);
+ } else {
+ spin_lock(&mlogbuf_wlock);
+ for (p = temp_buf; *p; p++) {
+ unsigned long next = (mlogbuf_end + 1) % MLOGBUF_SIZE;
+ if (next != mlogbuf_start) {
+ mlogbuf[mlogbuf_end] = *p;
+ mlogbuf_end = next;
+ } else {
+ /* buffer full */
+ break;
+ }
+ }
+ mlogbuf[mlogbuf_end] = '\0';
+ spin_unlock(&mlogbuf_wlock);
+ }
+}
+EXPORT_SYMBOL(ia64_mca_printk);
+
+/*
+ * Print buffered messages.
+ * NOTE: call this after returning normal context. (ex. from salinfod)
+ */
+void ia64_mlogbuf_dump(void)
+{
+ char temp_buf[MLOGBUF_MSGMAX];
+ char *p;
+ unsigned long index;
+ unsigned long flags;
+ unsigned int printed_len;
+
+ /* Get output from mlogbuf */
+ while (mlogbuf_start != mlogbuf_end) {
+ temp_buf[0] = '\0';
+ p = temp_buf;
+ printed_len = 0;
+
+ spin_lock_irqsave(&mlogbuf_rlock, flags);
+
+ index = mlogbuf_start;
+ while (index != mlogbuf_end) {
+ *p = mlogbuf[index];
+ index = (index + 1) % MLOGBUF_SIZE;
+ if (!*p)
+ break;
+ p++;
+ if (++printed_len >= MLOGBUF_MSGMAX - 1)
+ break;
+ }
+ *p = '\0';
+ if (temp_buf[0])
+ printk(temp_buf);
+ mlogbuf_start = index;
+
+ mlogbuf_timestamp = 0;
+ spin_unlock_irqrestore(&mlogbuf_rlock, flags);
+ }
+}
+EXPORT_SYMBOL(ia64_mlogbuf_dump);
+
+/*
+ * Call this if system is going to down or if immediate flushing messages to
+ * console is required. (ex. recovery was failed, crash dump is going to be
+ * invoked, long-wait rendezvous etc.)
+ * NOTE: this should be called from monarch.
+ */
+static void ia64_mlogbuf_finish(int wait)
+{
+ BREAK_LOGLEVEL(console_loglevel);
+
+ spin_lock_init(&mlogbuf_rlock);
+ ia64_mlogbuf_dump();
+ printk(KERN_EMERG "mlogbuf_finish: printing switched to urgent mode, "
+ "MCA/INIT might be dodgy or fail.\n");
+
+ if (!wait)
+ return;
+
+ /* wait for console */
+ printk("Delaying for 5 seconds...\n");
+ udelay(5*1000000);
+
+ mlogbuf_finished = 1;
+}
+EXPORT_SYMBOL(ia64_mlogbuf_finish);
+
+/*
+ * Print buffered messages from INIT context.
+ */
+static void ia64_mlogbuf_dump_from_init(void)
+{
+ if (mlogbuf_finished)
+ return;
+
+ if (mlogbuf_timestamp && (mlogbuf_timestamp + 30*HZ > jiffies)) {
+ printk(KERN_ERR "INIT: mlogbuf_dump is interrupted by INIT "
+ " and the system seems to be messed up.\n");
+ ia64_mlogbuf_finish(0);
+ return;
+ }
+
+ if (!spin_trylock(&mlogbuf_rlock)) {
+ printk(KERN_ERR "INIT: mlogbuf_dump is interrupted by INIT. "
+ "Generated messages other than stack dump will be "
+ "buffered to mlogbuf and will be printed later.\n");
+ printk(KERN_ERR "INIT: If messages would not printed after "
+ "this INIT, wait 30sec and assert INIT again.\n");
+ if (!mlogbuf_timestamp)
+ mlogbuf_timestamp = jiffies;
+ return;
+ }
+ spin_unlock(&mlogbuf_rlock);
+ ia64_mlogbuf_dump();
+}