MIPS: DEC: Rate-limit memory errors for non-KN01 parity systems

Similarly to memory errors in ECC systems also rate-limit memory parity
errors for KN02-BA, KN02-CA, KN04-BA, KN04-CA DECstation and DECsystem
models.  Unlike with ECC these events are always fatal and are less
likely to cause a message flood, but handle them the same way for
consistency.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/arch/mips/dec/kn02xa-berr.c b/arch/mips/dec/kn02xa-berr.c
index 9699fc4e6eb1c9b738ce3108f12155c88a27ca69..6e494db1e4372a038586ae1a26121cf609f7259d 100644 (file)
--- a/arch/mips/dec/kn02xa-berr.c
+++ b/arch/mips/dec/kn02xa-berr.c
@@ -6,12 +6,13 @@
  *     DECstation/DECsystem 5000/20, /25, /33 (KN02-CA), 5000/50
  *     (KN04-CA) systems.
  *
- *     Copyright (c) 2005  Maciej W. Rozycki
+ *     Copyright (c) 2005, 2026  Maciej W. Rozycki
  */
 
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
+#include <linux/ratelimit.h>
 #include <linux/types.h>
 
 #include <asm/addrspace.h>
@@ -50,6 +51,10 @@ static int dec_kn02xa_be_backend(struct pt_regs *regs, int is_fixup,
        static const char paritystr[] = "parity error";
        static const char lanestat[][4] = { " OK", "BAD" };
 
+       static DEFINE_RATELIMIT_STATE(rs,
+                                     DEFAULT_RATELIMIT_INTERVAL,
+                                     DEFAULT_RATELIMIT_BURST);
+
        const char *kind, *agent, *cycle, *event;
        unsigned long address;
 
@@ -79,18 +84,19 @@ static int dec_kn02xa_be_backend(struct pt_regs *regs, int is_fixup,
        if (is_fixup)
                action = MIPS_BE_FIXUP;
 
-       if (action != MIPS_BE_FIXUP)
+       if (action != MIPS_BE_FIXUP && __ratelimit(&rs)) {
                printk(KERN_ALERT "Bus error %s: %s %s %s at %#010lx\n",
                        kind, agent, cycle, event, address);
 
-       if (action != MIPS_BE_FIXUP && address < 0x10000000)
-               printk(KERN_ALERT "  Byte lane status %#3x -- "
-                      "#3: %s, #2: %s, #1: %s, #0: %s\n",
-                      (mer & KN02XA_MER_BYTERR) >> 8,
-                      lanestat[(mer & KN02XA_MER_BYTERR_3) != 0],
-                      lanestat[(mer & KN02XA_MER_BYTERR_2) != 0],
-                      lanestat[(mer & KN02XA_MER_BYTERR_1) != 0],
-                      lanestat[(mer & KN02XA_MER_BYTERR_0) != 0]);
+               if (address < 0x10000000)
+                       printk(KERN_ALERT "  Byte lane status %#3x -- "
+                              "#3: %s, #2: %s, #1: %s, #0: %s\n",
+                              (mer & KN02XA_MER_BYTERR) >> 8,
+                              lanestat[(mer & KN02XA_MER_BYTERR_3) != 0],
+                              lanestat[(mer & KN02XA_MER_BYTERR_2) != 0],
+                              lanestat[(mer & KN02XA_MER_BYTERR_1) != 0],
+                              lanestat[(mer & KN02XA_MER_BYTERR_0) != 0]);
+       }
 
        return action;
 }