[PATCH] ia64: Avoid deadlock when using printk() for MCA and INIT records

Port the ia64 mca.c clean up patches from 2.4.25-pre8 to 2.6.2-rc2.

The following 6 patches do :-

1 Avoid deadlock when using printk() for MCA and INIT records.
2 Delete all record printing code, moved to salinfo_decode in user space.
3 Mark variables and functions static where possible.
4 Delete dead variables and functions.
5 Reorder to remove the need for forward declarations and to consolidate
  related code.
6 Bjorn's printk cleanup.

Altogether they shrink mca.c from 2432 to 1339 lines and make it much
more readable.

The only functional change is the removal of any attempt to print the
CMC/CPE/MCA/INIT record contents in the kernel plus the addition of an
info printk to ia64_mca_check_errors(), to match 2.4.  Now we just get
one line to say that a record has been detected, except for MCA which
prints nothing at all.

diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
index 87af7534f8dba440f5f0618f082edb5045021e67..7db28d2c9a13ffe8531a5b5fcdd349dca71f986d 100644 (file)
--- a/arch/ia64/kernel/mca.c
+++ b/arch/ia64/kernel/mca.c
@@ -18,7 +18,7 @@
  * Copyright (C) 2000 Intel
  * Copyright (C) Chuck Fleckenstein (cfleck@co.intel.com)
  *
- * Copyright (C) 1999 Silicon Graphics, Inc.
+ * Copyright (C) 1999, 2004 Silicon Graphics, Inc.
  * Copyright (C) Vijay Chander(vijay@engr.sgi.com)
  *
  * 03/04/15 D. Mosberger Added INIT backtrace support.
@@ -40,6 +40,9 @@
  * 2003-12-08 Keith Owens <kaos@sgi.com>
  *            smp_call_function() must not be called from interrupt context (can
  *            deadlock on tasklist_lock).  Use keventd to call smp_call_function().
+ *
+ * 2004-02-01 Keith Owens <kaos@sgi.com>
+ *            Avoid deadlock when using printk() for MCA and INIT records.
  */
 #include <linux/config.h>
 #include <linux/types.h>
@@ -161,37 +164,34 @@ extern void salinfo_log_wakeup(int type, u8 *buffer, u64 size);
 /*
  *  ia64_mca_log_sal_error_record
  *
- *  This function retrieves a specified error record type from SAL,
- *  wakes up any processes waiting for error records, and sends it to
- *  the system log.
+ *  This function retrieves a specified error record type from SAL
+ *  and wakes up any processes waiting for error records.
  *
  *  Inputs  :   sal_info_type   (Type of error record MCA/CMC/CPE/INIT)
- *  Outputs :   platform error status
+ *             called_from_init (1 for boot processing)
  */
-int
+static void
 ia64_mca_log_sal_error_record(int sal_info_type, int called_from_init)
 {
        u8 *buffer;
        u64 size;
-       int platform_err;
+       int irq_safe = sal_info_type != SAL_INFO_TYPE_MCA && sal_info_type != SAL_INFO_TYPE_INIT;
+       static const char * const rec_name[] = { "MCA", "INIT", "CMC", "CPE" };
 
        size = ia64_log_get(sal_info_type, &buffer);
        if (!size)
-               return 0;
-
-       /* TODO:
-        * 1. analyze error logs to determine recoverability
-        * 2. perform error recovery procedures, if applicable
-        * 3. set ia64_os_mca_recovery_successful flag, if applicable
-        */
+               return;
 
        salinfo_log_wakeup(sal_info_type, buffer, size);
-       platform_err = ia64_log_print(sal_info_type, (prfunc_t)printk);
+
+       if (irq_safe || called_from_init)
+               printk(KERN_INFO "CPU %d: SAL log contains %s error record\n",
+                       smp_processor_id(),
+                       sal_info_type < ARRAY_SIZE(rec_name) ? rec_name[sal_info_type] : "UNKNOWN");
+
        /* Clear logs from corrected errors in case there's no user-level logger */
        if (sal_info_type == SAL_INFO_TYPE_CPE || sal_info_type == SAL_INFO_TYPE_CMC)
                ia64_sal_clear_state_info(sal_info_type);
-
-       return platform_err;
 }
 
 /*
@@ -1023,16 +1023,8 @@ ia64_return_to_sal_check(void)
 void
 ia64_mca_ucmc_handler(void)
 {
-       int platform_err = 0;
-
        /* Get the MCA error record and log it */
-       platform_err = ia64_mca_log_sal_error_record(SAL_INFO_TYPE_MCA, 0);
-
-       /*
-        *  Do Platform-specific mca error handling if required.
-        */
-       if (platform_err)
-               mca_handler_platform();
+       ia64_mca_log_sal_error_record(SAL_INFO_TYPE_MCA, 0);
 
        /*
         *  Wakeup all the processors which are spinning in the rendezvous
@@ -1337,6 +1329,8 @@ ia64_init_handler (struct pt_regs *pt, struct switch_stack *sw)
 {
        pal_min_state_area_t *ms;
 
+       oops_in_progress = 1;   /* avoid deadlock in printk, but it makes recovery dodgy */
+
        printk(KERN_INFO "Entered OS INIT handler. PSP=%lx\n",
                ia64_sal_to_os_handoff_state.proc_state_param);
 
@@ -1454,6 +1448,7 @@ ia64_log_get(int sal_info_type, u8 **buffer)
        sal_log_record_header_t     *log_buffer;
        u64                         total_len = 0;
        int                         s;
+       int irq_safe = sal_info_type != SAL_INFO_TYPE_MCA && sal_info_type != SAL_INFO_TYPE_INIT;
 
        IA64_LOG_LOCK(sal_info_type);
 
@@ -1465,8 +1460,10 @@ ia64_log_get(int sal_info_type, u8 **buffer)
        if (total_len) {
                IA64_LOG_INDEX_INC(sal_info_type);
                IA64_LOG_UNLOCK(sal_info_type);
-               IA64_MCA_DEBUG("ia64_log_get: SAL error record type %d retrieved. "
-                              "Record length = %ld\n", sal_info_type, total_len);
+               if (irq_safe) {
+                       IA64_MCA_DEBUG("ia64_log_get: SAL error record type %d retrieved. "
+                                      "Record length = %ld\n", sal_info_type, total_len);
+               }
                *buffer = (u8 *) log_buffer;
                return total_len;
        } else {