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authorMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>2013-12-16 10:46:24 +0530
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-03-07 15:52:10 +1100
commit55672ecfa21f23616541c50e0e687f14f9ecf165 (patch)
tree1584ec952c56dcc7b2894085ddea9de3825c8d08 /arch/powerpc/kernel/prom.c
parentd2a36071ef8dd24dceb95c3d9b05aaeac987b447 (diff)
powerpc/book3s: Recover from MC in sapphire on SCOM read via MMIO.
Detect and recover from machine check when inside opal on a special scom load instructions. On specific SCOM read via MMIO we may get a machine check exception with SRR0 pointing inside opal. To recover from MC in this scenario, get a recovery instruction address and return to it from MC. OPAL will export the machine check recoverable ranges through device tree node mcheck-recoverable-ranges under ibm,opal: # hexdump /proc/device-tree/ibm,opal/mcheck-recoverable-ranges 0000000 0000 0000 3000 2804 0000 000c 0000 0000 0000010 3000 2814 0000 0000 3000 27f0 0000 000c 0000020 0000 0000 3000 2814 xxxx xxxx xxxx xxxx 0000030 llll llll yyyy yyyy yyyy yyyy ... ... # where: xxxx xxxx xxxx xxxx = Starting instruction address llll llll = Length of the address range. yyyy yyyy yyyy yyyy = recovery address Each recoverable address range entry is (start address, len, recovery address), 2 cells each for start and recovery address, 1 cell for len, totalling 5 cells per entry. During kernel boot time, build up the recovery table with the list of recovery ranges from device-tree node which will be used during machine check exception to recover from MMIO SCOM UE. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/prom.c')
-rw-r--r--arch/powerpc/kernel/prom.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index f58c0d3aaeb4..d711b7eb05aa 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -752,6 +752,11 @@ void __init early_init_devtree(void *params)
spinning_secondaries = boot_cpu_count - 1;
#endif
+#ifdef CONFIG_PPC_POWERNV
+ /* Scan and build the list of machine check recoverable ranges */
+ of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL);
+#endif
+
DBG(" <- early_init_devtree()\n");
}