powerpc/pseries: Update the device tree correctly for drconf memory add/remove

This updates the device tree manipulation routines so that memory
add/remove of lmbs represented under the
ibm,dynamic-reconfiguration-memory node of the device tree invokes the
hotplug notifier chain.

This change is needed because of the change in the way memory is
represented under the ibm,dynamic-reconfiguration-memory node.  All lmbs
are described in the ibm,dynamic-memory property instead of having a
separate node for each lmb as in previous device tree layouts.  This
requires the update_node() routine to check for updates to the
ibm,dynamic-memory property and invoke the hotplug notifier chain.

This also updates the pseries hotplug notifier to be able to gather information
for lmbs represented under the ibm,dynamic-reconfiguration-memory node and
have the lmbs added/removed.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

3 files changed, 104 insertions, 33 deletions

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 18a8138ef99f..a1a368dd2d99 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -15,32 +15,11 @@
 #include <asm/machdep.h>
 #include <asm/pSeries_reconfig.h>
 
-static int pseries_remove_memory(struct device_node *np)
+static int pseries_remove_lmb(unsigned long base, unsigned int lmb_size)
 {
-        const char *type;
-        const unsigned int *regs;
-        unsigned long base;
-        unsigned int lmb_size;
-        u64 start_pfn, start;
+        unsigned long start, start_pfn;
         struct zone *zone;
-        int ret = -EINVAL;
-
-        /*
-         * Check to see if we are actually removing memory
-         */
-        type = of_get_property(np, "device_type", NULL);
-        if (type == NULL || strcmp(type, "memory") != 0)
-                return 0;
-
-        /*
-         * Find the bae address and size of the lmb
-         */
-        regs = of_get_property(np, "reg", NULL);
-        if (!regs)
-                return ret;
-
-        base = *(unsigned long *)regs;
-        lmb_size = regs[3];
+        int ret;
 
         start_pfn = base >> PFN_SECTION_SHIFT;
         zone = page_zone(pfn_to_page(start_pfn));
@@ -71,13 +50,41 @@ static int pseries_remove_memory(struct device_node *np)
         return ret;
 }
 
+static int pseries_remove_memory(struct device_node *np)
+{
+        const char *type;
+        const unsigned int *regs;
+        unsigned long base;
+        unsigned int lmb_size;
+        int ret = -EINVAL;
+
+        /*
+         * Check to see if we are actually removing memory
+         */
+        type = of_get_property(np, "device_type", NULL);
+        if (type == NULL || strcmp(type, "memory") != 0)
+                return 0;
+
+        /*
+         * Find the bae address and size of the lmb
+         */
+        regs = of_get_property(np, "reg", NULL);
+        if (!regs)
+                return ret;
+
+        base = *(unsigned long *)regs;
+        lmb_size = regs[3];
+
+        ret = pseries_remove_lmb(base, lmb_size);
+        return ret;
+}
+
 static int pseries_add_memory(struct device_node *np)
 {
         const char *type;
         const unsigned int *regs;
         unsigned long base;
         unsigned int lmb_size;
-        u64 start_pfn;
         int ret = -EINVAL;
 
         /*
@@ -100,8 +107,37 @@ static int pseries_add_memory(struct device_node *np)
         /*
          * Update memory region to represent the memory add
          */
-        lmb_add(base, lmb_size);
-        return 0;
+        ret = lmb_add(base, lmb_size);
+        return (ret < 0) ? -EINVAL : 0;
+}
+
+static int pseries_drconf_memory(unsigned long *base, unsigned int action)
+{
+        struct device_node *np;
+        const unsigned long *lmb_size;
+        int rc;
+
+        np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+        if (!np)
+                return -EINVAL;
+
+        lmb_size = of_get_property(np, "ibm,lmb-size", NULL);
+        if (!lmb_size) {
+                of_node_put(np);
+                return -EINVAL;
+        }
+
+        if (action == PSERIES_DRCONF_MEM_ADD) {
+                rc = lmb_add(*base, *lmb_size);
+                rc = (rc < 0) ? -EINVAL : 0;
+        } else if (action == PSERIES_DRCONF_MEM_REMOVE) {
+                rc = pseries_remove_lmb(*base, *lmb_size);
+        } else {
+                rc = -EINVAL;
+        }
+
+        of_node_put(np);
+        return rc;
 }
 
 static int pseries_memory_notifier(struct notifier_block *nb,
@@ -118,6 +154,11 @@ static int pseries_memory_notifier(struct notifier_block *nb,
                 if (pseries_remove_memory(node))
                         err = NOTIFY_BAD;
                 break;
+        case PSERIES_DRCONF_MEM_ADD:
+        case PSERIES_DRCONF_MEM_REMOVE:
+                if (pseries_drconf_memory(node, action))
+                        err = NOTIFY_BAD;
+                break;
         default:
                 err = NOTIFY_DONE;
                 break;
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index dfa2ebd2deb5..7637bd38c795 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -422,8 +422,8 @@ static int do_update_property(char *buf, size_t bufsize)
 {
         struct device_node *np;
         unsigned char *value;
-        char *name, *end;
-        int length;
+        char *name, *end, *next_prop;
+        int rc, length;
         struct property *newprop, *oldprop;
         buf = parse_node(buf, bufsize, &np);
         end = buf + bufsize;
@@ -431,7 +431,8 @@ static int do_update_property(char *buf, size_t bufsize)
         if (!np)
                 return -ENODEV;
 
-        if (parse_next_property(buf, end, &name, &length, &value) == NULL)
+        next_prop = parse_next_property(buf, end, &name, &length, &value);
+        if (!next_prop)
                 return -EINVAL;
 
         newprop = new_property(name, length, value, NULL);
@@ -442,7 +443,34 @@ static int do_update_property(char *buf, size_t bufsize)
         if (!oldprop)
                 return -ENODEV;
 
-        return prom_update_property(np, newprop, oldprop);
+        rc = prom_update_property(np, newprop, oldprop);
+        if (rc)
+                return rc;
+
+        /* For memory under the ibm,dynamic-reconfiguration-memory node
+         * of the device tree, adding and removing memory is just an update
+         * to the ibm,dynamic-memory property instead of adding/removing a
+         * memory node in the device tree.  For these cases we still need to
+         * involve the notifier chain.
+         */
+        if (!strcmp(name, "ibm,dynamic-memory")) {
+                int action;
+
+                next_prop = parse_next_property(next_prop, end, &name,
+                                                &length, &value);
+                if (!next_prop)
+                        return -EINVAL;
+
+                if (!strcmp(name, "add"))
+                        action = PSERIES_DRCONF_MEM_ADD;
+                else
+                        action = PSERIES_DRCONF_MEM_REMOVE;
+
+                blocking_notifier_call_chain(&pSeries_reconfig_chain,
+                                             action, value);
+        }
+
+        return 0;
 }
 
 /**
diff --git a/include/asm-powerpc/pSeries_reconfig.h b/include/asm-powerpc/pSeries_reconfig.h
index ea6cfb8efb84..e482e5352e69 100644
--- a/include/asm-powerpc/pSeries_reconfig.h
+++ b/include/asm-powerpc/pSeries_reconfig.h
@@ -9,8 +9,10 @@
  * added or removed on pSeries systems.
  */
 
-#define PSERIES_RECONFIG_ADD    0x0001
-#define PSERIES_RECONFIG_REMOVE 0x0002
+#define PSERIES_RECONFIG_ADD            0x0001
+#define PSERIES_RECONFIG_REMOVE         0x0002
+#define PSERIES_DRCONF_MEM_ADD          0x0003
+#define PSERIES_DRCONF_MEM_REMOVE       0x0004
 
 #ifdef CONFIG_PPC_PSERIES
 extern int pSeries_reconfig_notifier_register(struct notifier_block *);