[POWERPC] pseries: phyp dump: Tracking memory range freed

This tracks the size freed.  For now it does a simple rudimentary
calculation of the ranges freed.  The idea is to keep it simple at the
external shell script level and send in large chunks for now.
Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/pseries/phyp_dump.c

@@ -261,6 +261,39 @@ static void release_memory_range(unsigned long start_pfn,
 	}
 }
 
+/**
+ * track_freed_range -- Counts the range being freed.
+ * Once the counter goes to zero, it re-registers dump for
+ * future use.
+ */
+static void
+track_freed_range(unsigned long addr, unsigned long length)
+{
+	static unsigned long scratch_area_size, reserved_area_size;
+
+	if (addr < phyp_dump_info->init_reserve_start)
+		return;
+
+	if ((addr >= phyp_dump_info->init_reserve_start) &&
+	    (addr <= phyp_dump_info->init_reserve_start +
+	     phyp_dump_info->init_reserve_size))
+		reserved_area_size += length;
+
+	if ((addr >= phyp_dump_info->reserved_scratch_addr) &&
+	    (addr <= phyp_dump_info->reserved_scratch_addr +
+	     phyp_dump_info->reserved_scratch_size))
+		scratch_area_size += length;
+
+	if ((reserved_area_size == phyp_dump_info->init_reserve_size) &&
+	    (scratch_area_size == phyp_dump_info->reserved_scratch_size)) {
+
+		invalidate_last_dump(&phdr,
+				phyp_dump_info->reserved_scratch_addr);
+		register_dump_area(&phdr,
+				phyp_dump_info->reserved_scratch_addr);
+	}
+}
+
 /* ------------------------------------------------- */
 /**
  * sysfs_release_region -- sysfs interface to release memory range.
@@ -285,6 +318,8 @@ static ssize_t store_release_region(struct kobject *kobj,
 	if (ret != 2)
 		return -EINVAL;
 
+	track_freed_range(start_addr, length);
+
 	/* Range-check - don't free any reserved memory that
 	 * wasn't reserved for phyp-dump */
 	if (start_addr < phyp_dump_info->init_reserve_start)