powerpc/pseries: Update dynamic cache nodes for suspend/resume operation

pHyp can change cache nodes for suspend/resume operation. Currently the
device tree is updated by drmgr in userspace after all non boot CPUs are
enabled. Hence, we do not modify the cache list based on the latest cache
nodes. Also we do not remove cache entries for the primary CPU.

This patch removes the cache list for the boot CPU, updates the device tree
before enabling nonboot CPUs and adds cache list for the boot cpu.

This patch also has the side effect that older versions of drmgr will
perform a second device tree update from userspace. While this is a
redundant waste of a couple cycles it is harmless since firmware returns the
same data for the subsequent update-nodes/properties rtas calls.

Signed-off-by: Haren Myneni <hbabu@us.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/rtas.h

@@ -283,6 +283,7 @@ extern void pSeries_log_error(char *buf, unsigned int err_type, int fatal);
 
 #ifdef CONFIG_PPC_PSERIES
 extern int pseries_devicetree_update(s32 scope);
+extern void post_mobility_fixup(void);
 #endif
 
 #ifdef CONFIG_PPC_RTAS_DAEMON

arch/powerpc/kernel/cacheinfo.c

@@ -756,7 +756,10 @@ void cacheinfo_cpu_online(unsigned int cpu_id)
 	cacheinfo_sysfs_populate(cpu_id, cache);
 }
 
-#ifdef CONFIG_HOTPLUG_CPU /* functions needed for cpu offline */
+/* functions needed to remove cache entry for cpu offline or suspend/resume */
+
+#if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \
+    defined(CONFIG_HOTPLUG_CPU)
 
 static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
 {
@@ -843,4 +846,4 @@ void cacheinfo_cpu_offline(unsigned int cpu_id)
 	if (cache)
 		cache_cpu_clear(cache, cpu_id);
 }
-#endif /* CONFIG_HOTPLUG_CPU */
+#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */

arch/powerpc/platforms/pseries/suspend.c

@@ -26,6 +26,7 @@
 #include <asm/mmu.h>
 #include <asm/rtas.h>
 #include <asm/topology.h>
+#include "../../kernel/cacheinfo.h"
 
 static u64 stream_id;
 static struct device suspend_dev;
@@ -78,6 +79,23 @@ static int pseries_suspend_cpu(void)
 	return 0;
 }
 
+/**
+ * pseries_suspend_enable_irqs
+ *
+ * Post suspend configuration updates
+ *
+ **/
+static void pseries_suspend_enable_irqs(void)
+{
+	/*
+	 * Update configuration which can be modified based on device tree
+	 * changes during resume.
+	 */
+	cacheinfo_cpu_offline(smp_processor_id());
+	post_mobility_fixup();
+	cacheinfo_cpu_online(smp_processor_id());
+}
+
 /**
  * pseries_suspend_enter - Final phase of hibernation
  *
@@ -235,6 +253,7 @@ static int __init pseries_suspend_init(void)
 		return rc;
 
 	ppc_md.suspend_disable_cpu = pseries_suspend_cpu;
+	ppc_md.suspend_enable_irqs = pseries_suspend_enable_irqs;
 	suspend_set_ops(&pseries_suspend_ops);
 	return 0;
 }