MIPS: Cavium: Add EDAC support.

Drivers for EDAC on Cavium.  Supported subsystems are:

 o CPU primary caches.  These are parity protected only, so only error
   reporting.
 o Second level cache - ECC protected, provides SECDED.
 o Memory: ECC / SECDEC if used with suitable DRAM modules.  The driver will
   will only initialize if ECC is enabled on a system so is safe to run on
   non-ECC memory.
 o PCI: Parity error reporting

Since it is very hard to test this sort of code the implementation is very
conservative and uses polling where possible for now.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: Borislav Petkov <borislav.petkov@amd.com>

arch/mips/Kconfig

@@ -774,6 +774,7 @@ config CAVIUM_OCTEON_REFERENCE_BOARD
 	select DMA_COHERENT
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select EDAC_SUPPORT
 	select SYS_SUPPORTS_HOTPLUG_CPU
 	select SYS_HAS_EARLY_PRINTK
 	select SYS_HAS_CPU_CAVIUM_OCTEON

arch/mips/cavium-octeon/setup.c

@@ -4,9 +4,11 @@
  * for more details.
  *
  * Copyright (C) 2004-2007 Cavium Networks
- * Copyright (C) 2008 Wind River Systems
+ * Copyright (C) 2008, 2009 Wind River Systems
+ *   written by Ralf Baechle <ralf@linux-mips.org>
  */
 #include <linux/init.h>
+#include <linux/kernel.h>
 #include <linux/console.h>
 #include <linux/delay.h>
 #include <linux/export.h>
@@ -821,3 +823,29 @@ void __init device_tree_init(void)
 	}
 	unflatten_device_tree();
 }
+
+static char *edac_device_names[] = {
+	"co_l2c_edac",
+	"co_lmc_edac",
+	"co_pc_edac",
+};
+
+static int __init edac_devinit(void)
+{
+	struct platform_device *dev;
+	int i, err = 0;
+	char *name;
+
+	for (i = 0; i < ARRAY_SIZE(edac_device_names); i++) {
+		name = edac_device_names[i];
+		dev = platform_device_register_simple(name, -1, NULL, 0);
+		if (IS_ERR(dev)) {
+			pr_err("Registation of %s failed!\n", name);
+			err = PTR_ERR(dev);
+		}
+	}
+
+	return err;
+}
+
+device_initcall(edac_devinit);

arch/mips/mm/c-octeon.c

@@ -5,6 +5,7 @@
  *
  * Copyright (C) 2005-2007 Cavium Networks
  */
+#include <linux/export.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
@@ -28,6 +29,7 @@
 #include <asm/octeon/octeon.h>
 
 unsigned long long cache_err_dcache[NR_CPUS];
+EXPORT_SYMBOL_GPL(cache_err_dcache);
 
 /**
  * Octeon automatically flushes the dcache on tlb changes, so
@@ -288,42 +290,42 @@ void __cpuinit octeon_cache_init(void)
  * Handle a cache error exception
  */
 
-static void  cache_parity_error_octeon(int non_recoverable)
+static RAW_NOTIFIER_HEAD(co_cache_error_chain);
+
+int register_co_cache_error_notifier(struct notifier_block *nb)
 {
-	unsigned long coreid = cvmx_get_core_num();
-	uint64_t icache_err = read_octeon_c0_icacheerr();
+	return raw_notifier_chain_register(&co_cache_error_chain, nb);
+}
+EXPORT_SYMBOL_GPL(register_co_cache_error_notifier);
 
-	pr_err("Cache error exception:\n");
-	pr_err("cp0_errorepc == %lx\n", read_c0_errorepc());
-	if (icache_err & 1) {
-		pr_err("CacheErr (Icache) == %llx\n",
-		       (unsigned long long)icache_err);
-		write_octeon_c0_icacheerr(0);
-	}
-	if (cache_err_dcache[coreid] & 1) {
-		pr_err("CacheErr (Dcache) == %llx\n",
-		       (unsigned long long)cache_err_dcache[coreid]);
-		cache_err_dcache[coreid] = 0;
-	}
+int unregister_co_cache_error_notifier(struct notifier_block *nb)
+{
+	return raw_notifier_chain_unregister(&co_cache_error_chain, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_co_cache_error_notifier);
 
-	if (non_recoverable)
-		panic("Can't handle cache error: nested exception");
+static inline int co_cache_error_call_notifiers(unsigned long val)
+{
+	return raw_notifier_call_chain(&co_cache_error_chain, val, NULL);
 }
 
 /**
  * Called when the the exception is recoverable
  */
-
 asmlinkage void cache_parity_error_octeon_recoverable(void)
 {
-	cache_parity_error_octeon(0);
+	co_cache_error_call_notifiers(0);
 }
 
 /**
  * Called when the the exception is not recoverable
+ *
+ * The issue not that the cache error exception itself was non-recoverable
+ * but that due to nesting of exception may have lost some state so can't
+ * continue.
  */
-
 asmlinkage void cache_parity_error_octeon_non_recoverable(void)
 {
-	cache_parity_error_octeon(1);
+	co_cache_error_call_notifiers(1);
+	panic("Can't handle cache error: nested exception");
 }

arch/mips/pci/pci-octeon.c

@@ -11,6 +11,7 @@
 #include <linux/interrupt.h>
 #include <linux/time.h>
 #include <linux/delay.h>
+#include <linux/platform_device.h>
 #include <linux/swiotlb.h>
 
 #include <asm/time.h>
@@ -704,6 +705,9 @@ static int __init octeon_pci_setup(void)
 	 */
 	cvmx_write_csr(CVMX_NPI_PCI_INT_SUM2, -1);
 
+	if (IS_ERR(platform_device_register_simple("co_pci_edac", 0, NULL, 0)))
+		pr_err("Registation of co_pci_edac failed!\n");
+
 	octeon_pci_dma_init();
 
 	return 0;