powerpc/e500mc: Implement machine check handler.

Most of the MSCR bit assigments are different in e500mc versus
e500, and they are now write-one-to-clear.

Some e500mc machine check conditions are made recoverable (as long as
they aren't stuck on), most notably L1 instruction cache parity errors.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

2 files changed, 88 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index 9556be903e96..87aa0f3c6047 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -1840,7 +1840,7 @@ static struct cpu_spec __initdata cpu_specs[] = {
                 .oprofile_cpu_type      = "ppc/e500mc",
                 .oprofile_type          = PPC_OPROFILE_FSL_EMB,
                 .cpu_setup              = __setup_cpu_e500mc,
-                .machine_check          = machine_check_e500,
+                .machine_check          = machine_check_e500mc,
                 .platform               = "ppce500mc",
         },
         {       /* default match */
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index ca7ce85ebc2e..5ed46758f4e9 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1,5 +1,6 @@
 /*
  *  Copyright (C) 1995-1996  Gary Thomas (gdt@linuxppc.org)
+ *  Copyright 2007-2010 Freescale Semiconductor, Inc.
  *
  *  This program is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU General Public License
@@ -305,7 +306,7 @@ static inline int check_io_access(struct pt_regs *regs)
 #ifndef CONFIG_FSL_BOOKE
 #define get_mc_reason(regs)     ((regs)->dsisr)
 #else
-#define get_mc_reason(regs)     (mfspr(SPRN_MCSR) & MCSR_MASK)
+#define get_mc_reason(regs)     (mfspr(SPRN_MCSR))
 #endif
 #define REASON_FP               ESR_FP
 #define REASON_ILLEGAL          (ESR_PIL | ESR_PUO)
@@ -421,6 +422,91 @@ int machine_check_47x(struct pt_regs *regs)
         return 0;
 }
 #elif defined(CONFIG_E500)
+int machine_check_e500mc(struct pt_regs *regs)
+{
+        unsigned long mcsr = mfspr(SPRN_MCSR);
+        unsigned long reason = mcsr;
+        int recoverable = 1;
+
+        printk("Machine check in kernel mode.\n");
+        printk("Caused by (from MCSR=%lx): ", reason);
+
+        if (reason & MCSR_MCP)
+                printk("Machine Check Signal\n");
+
+        if (reason & MCSR_ICPERR) {
+                printk("Instruction Cache Parity Error\n");
+
+                /*
+                 * This is recoverable by invalidating the i-cache.
+                 */
+                mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI);
+                while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI)
+                        ;
+
+                /*
+                 * This will generally be accompanied by an instruction
+                 * fetch error report -- only treat MCSR_IF as fatal
+                 * if it wasn't due to an L1 parity error.
+                 */
+                reason &= ~MCSR_IF;
+        }
+
+        if (reason & MCSR_DCPERR_MC) {
+                printk("Data Cache Parity Error\n");
+                recoverable = 0;
+        }
+
+        if (reason & MCSR_L2MMU_MHIT) {
+                printk("Hit on multiple TLB entries\n");
+                recoverable = 0;
+        }
+
+        if (reason & MCSR_NMI)
+                printk("Non-maskable interrupt\n");
+
+        if (reason & MCSR_IF) {
+                printk("Instruction Fetch Error Report\n");
+                recoverable = 0;
+        }
+
+        if (reason & MCSR_LD) {
+                printk("Load Error Report\n");
+                recoverable = 0;
+        }
+
+        if (reason & MCSR_ST) {
+                printk("Store Error Report\n");
+                recoverable = 0;
+        }
+
+        if (reason & MCSR_LDG) {
+                printk("Guarded Load Error Report\n");
+                recoverable = 0;
+        }
+
+        if (reason & MCSR_TLBSYNC)
+                printk("Simultaneous tlbsync operations\n");
+
+        if (reason & MCSR_BSL2_ERR) {
+                printk("Level 2 Cache Error\n");
+                recoverable = 0;
+        }
+
+        if (reason & MCSR_MAV) {
+                u64 addr;
+
+                addr = mfspr(SPRN_MCAR);
+                addr |= (u64)mfspr(SPRN_MCARU) << 32;
+
+                printk("Machine Check %s Address: %#llx\n",
+                       reason & MCSR_MEA ? "Effective" : "Physical", addr);
+        }
+
+        mtspr(SPRN_MCSR, mcsr);
+        return mfspr(SPRN_MCSR) == 0 && recoverable;
+}
+
 int machine_check_e500(struct pt_regs *regs)
 {
         unsigned long reason = get_mc_reason(regs);