auto import from //depot/cupcake/@135843
diff --git a/libpagemap/pm_map.c b/libpagemap/pm_map.c
new file mode 100644
index 0000000..f683ba6
--- /dev/null
+++ b/libpagemap/pm_map.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <pagemap/pagemap.h>
+
+int pm_map_pagemap(pm_map_t *map, uint64_t **pagemap_out, size_t *len) {
+    if (!map)
+        return -1;
+
+    return pm_process_pagemap_range(map->proc, map->start, map->end,
+                                    pagemap_out, len);
+}
+
+int pm_map_usage(pm_map_t *map, pm_memusage_t *usage_out) {
+    uint64_t *pagemap;
+    size_t len, i;
+    uint64_t count;
+    pm_memusage_t usage;
+    int error;
+
+    if (!map || !usage_out)
+        return -1;
+
+    error = pm_map_pagemap(map, &pagemap, &len);
+    if (error) return error;
+
+    pm_memusage_zero(&usage);
+
+    for (i = 0; i < len; i++) {
+        if (!PM_PAGEMAP_PRESENT(pagemap[i]) ||
+            PM_PAGEMAP_SWAPPED(pagemap[i]))
+            continue;
+
+        error = pm_kernel_count(map->proc->ker, PM_PAGEMAP_PFN(pagemap[i]),
+                                &count);
+        if (error) goto out;
+
+        usage.vss += map->proc->ker->pagesize;
+        usage.rss += (count >= 1) ? (map->proc->ker->pagesize) : (0);
+        usage.pss += (count >= 1) ? (map->proc->ker->pagesize / count) : (0);
+        usage.uss += (count == 1) ? (map->proc->ker->pagesize) : (0);
+    }
+
+    memcpy(usage_out, &usage, sizeof(usage));
+
+    error = 0;
+
+out:    
+    free(pagemap);
+
+    return error;
+}
+
+int pm_map_workingset(pm_map_t *map, pm_memusage_t *ws_out) {
+    uint64_t *pagemap;
+    size_t len, i;
+    uint64_t count, flags;
+    pm_memusage_t ws;
+    int error;
+
+    if (!map || !ws_out)
+        return -1;
+
+    error = pm_map_pagemap(map, &pagemap, &len);
+    if (error) return error;
+
+    pm_memusage_zero(&ws);
+    
+    for (i = 0; i < len; i++) {
+        if (!PM_PAGEMAP_PRESENT(pagemap[i]) ||
+            PM_PAGEMAP_SWAPPED(pagemap[i]))
+            continue;
+
+        error = pm_kernel_flags(map->proc->ker, PM_PAGEMAP_PFN(pagemap[i]),
+                                &flags);
+        if (error) goto out;
+
+        if (!(flags & PM_PAGE_REFERENCED)) 
+            continue;
+
+        error = pm_kernel_count(map->proc->ker, PM_PAGEMAP_PFN(pagemap[i]),
+                                &count);
+        if (error) goto out;
+
+        ws.vss += map->proc->ker->pagesize;
+        ws.rss += (count >= 1) ? (map->proc->ker->pagesize) : (0);
+        ws.pss += (count >= 1) ? (map->proc->ker->pagesize / count) : (0);
+        ws.uss += (count == 1) ? (map->proc->ker->pagesize) : (0);
+    }
+
+    memcpy(ws_out, &ws, sizeof(ws));
+
+    error = 0;
+
+out:
+    free(pagemap);
+
+    return 0;
+}
+
+int pm_map_destroy(pm_map_t *map) {
+    if (!map)
+        return -1;
+
+    free(map->name);
+    free(map);
+
+    return 0;
+}