From 82a9a4809f4cb4ce3f17da99a8150df8455fa096 Mon Sep 17 00:00:00 2001
From: Scott Wood <scottwood@freescale.com>
Date: Thu, 16 Jun 2011 14:09:17 -0500
Subject: [PATCH] powerpc/e500: fix breakage with fsl_rio_mcheck_exception
The wrong MCSR bit was being used on e500mc. MCSR_BUS_RBERR only exists
on e500v1/v2. Use MCSR_LD on e500mc, and remove all MCSR checking
in fsl_rio_mcheck_exception as we now no longer call that function
if the appropriate bit in MCSR is not set.
If RIO support was enabled at compile-time, but was never probed, just
return from fsl_rio_mcheck_exception rather than dereference a NULL
pointer.
TODO: There is still a remaining, though comparitively minor, issue in
that this recovery mechanism will falsely engage if there's an unrelated
MCSR_LD event at the same time as a RIO error.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
arch/powerpc/kernel/traps.c | 2 +-
arch/powerpc/sysdev/fsl_rio.c | 35 ++++++++++++++++++-----------------
2 files changed, 19 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 0ff4ab98d50ca..6414a0d5ba65b 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -425,7 +425,7 @@ int machine_check_e500mc(struct pt_regs *regs)
unsigned long reason = mcsr;
int recoverable = 1;
- if (reason & MCSR_BUS_RBERR) {
+ if (reason & MCSR_LD) {
recoverable = fsl_rio_mcheck_exception(regs);
if (recoverable == 1)
goto silent_out;
diff --git a/arch/powerpc/sysdev/fsl_rio.c b/arch/powerpc/sysdev/fsl_rio.c
index 5b206a2fe17c4..b3fd081d56f5f 100644
--- a/arch/powerpc/sysdev/fsl_rio.c
+++ b/arch/powerpc/sysdev/fsl_rio.c
@@ -283,23 +283,24 @@ static void __iomem *rio_regs_win;
#ifdef CONFIG_E500
int fsl_rio_mcheck_exception(struct pt_regs *regs)
{
- const struct exception_table_entry *entry = NULL;
- unsigned long reason = mfspr(SPRN_MCSR);
-
- if (reason & MCSR_BUS_RBERR) {
- reason = in_be32((u32 *)(rio_regs_win + RIO_LTLEDCSR));
- if (reason & (RIO_LTLEDCSR_IER | RIO_LTLEDCSR_PRT)) {
- /* Check if we are prepared to handle this fault */
- entry = search_exception_tables(regs->nip);
- if (entry) {
- pr_debug("RIO: %s - MC Exception handled\n",
- __func__);
- out_be32((u32 *)(rio_regs_win + RIO_LTLEDCSR),
- 0);
- regs->msr |= MSR_RI;
- regs->nip = entry->fixup;
- return 1;
- }
+ const struct exception_table_entry *entry;
+ unsigned long reason;
+
+ if (!rio_regs_win)
+ return 0;
+
+ reason = in_be32((u32 *)(rio_regs_win + RIO_LTLEDCSR));
+ if (reason & (RIO_LTLEDCSR_IER | RIO_LTLEDCSR_PRT)) {
+ /* Check if we are prepared to handle this fault */
+ entry = search_exception_tables(regs->nip);
+ if (entry) {
+ pr_debug("RIO: %s - MC Exception handled\n",
+ __func__);
+ out_be32((u32 *)(rio_regs_win + RIO_LTLEDCSR),
+ 0);
+ regs->msr |= MSR_RI;
+ regs->nip = entry->fixup;
+ return 1;
}
}
--
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