memory hotplug: Define memory_block_size_bytes for powerpc/pseries

Define a version of memory_block_size_bytes() for powerpc/pseries such that
a memory block spans an entire lmb.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 53 insertions, 13 deletions

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index bc8803664140..33867ec4a234 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -17,6 +17,54 @@
 #include <asm/pSeries_reconfig.h>
 #include <asm/sparsemem.h>
 
+static unsigned long get_memblock_size(void)
+{
+        struct device_node *np;
+        unsigned int memblock_size = 0;
+
+        np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+        if (np) {
+                const unsigned long *size;
+
+                size = of_get_property(np, "ibm,lmb-size", NULL);
+                memblock_size = size ? *size : 0;
+
+                of_node_put(np);
+        } else {
+                unsigned int memzero_size = 0;
+                const unsigned int *regs;
+
+                np = of_find_node_by_path("/memory@0");
+                if (np) {
+                        regs = of_get_property(np, "reg", NULL);
+                        memzero_size = regs ? regs[3] : 0;
+                        of_node_put(np);
+                }
+
+                if (memzero_size) {
+                        /* We now know the size of memory@0, use this to find
+                         * the first memoryblock and get its size.
+                         */
+                        char buf[64];
+
+                        sprintf(buf, "/memory@%x", memzero_size);
+                        np = of_find_node_by_path(buf);
+                        if (np) {
+                                regs = of_get_property(np, "reg", NULL);
+                                memblock_size = regs ? regs[3] : 0;
+                                of_node_put(np);
+                        }
+                }
+        }
+
+        return memblock_size;
+}
+
+unsigned long memory_block_size_bytes(void)
+{
+        return get_memblock_size();
+}
+
 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
 {
         unsigned long start, start_pfn;
@@ -127,30 +175,22 @@ static int pseries_add_memory(struct device_node *np)
 
 static int pseries_drconf_memory(unsigned long *base, unsigned int action)
 {
-        struct device_node *np;
-        const unsigned long *lmb_size;
+        unsigned long memblock_size;
         int rc;
 
-        np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
-        if (!np)
+        memblock_size = get_memblock_size();
+        if (!memblock_size)
                 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 = memblock_add(*base, *lmb_size);
+                rc = memblock_add(*base, memblock_size);
                 rc = (rc < 0) ? -EINVAL : 0;
         } else if (action == PSERIES_DRCONF_MEM_REMOVE) {
-                rc = pseries_remove_memblock(*base, *lmb_size);
+                rc = pseries_remove_memblock(*base, memblock_size);
         } else {
                 rc = -EINVAL;
         }
 
-        of_node_put(np);
         return rc;
 }