Merge tag 'amd-drm-next-5.7-2020-02-26' of git://people.freedesktop.org/~agd5f/linux...

[linux-2.6-microblaze.git] / lib / xarray.c

diff --git a/lib/xarray.c b/lib/xarray.c
index 1237c21..1d9fab7 100644 (file)
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1,7 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * XArray implementation
- * Copyright (c) 2017 Microsoft Corporation
+ * Copyright (c) 2017-2018 Microsoft Corporation
+ * Copyright (c) 2018-2020 Oracle
  * Author: Matthew Wilcox <willy@infradead.org>
  */
 
@@ -967,6 +968,7 @@ void xas_pause(struct xa_state *xas)
        if (xas_invalid(xas))
                return;
 
+       xas->xa_node = XAS_RESTART;
        if (node) {
                unsigned int offset = xas->xa_offset;
                while (++offset < XA_CHUNK_SIZE) {
@@ -974,10 +976,11 @@ void xas_pause(struct xa_state *xas)
                                break;
                }
                xas->xa_index += (offset - xas->xa_offset) << node->shift;
+               if (xas->xa_index == 0)
+                       xas->xa_node = XAS_BOUNDS;
        } else {
                xas->xa_index++;
        }
-       xas->xa_node = XAS_RESTART;
 }
 EXPORT_SYMBOL_GPL(xas_pause);
 
@@ -1079,13 +1082,15 @@ void *xas_find(struct xa_state *xas, unsigned long max)
 {
        void *entry;
 
-       if (xas_error(xas))
+       if (xas_error(xas) || xas->xa_node == XAS_BOUNDS)
                return NULL;
+       if (xas->xa_index > max)
+               return set_bounds(xas);
 
        if (!xas->xa_node) {
                xas->xa_index = 1;
                return set_bounds(xas);
-       } else if (xas_top(xas->xa_node)) {
+       } else if (xas->xa_node == XAS_RESTART) {
                entry = xas_load(xas);
                if (entry || xas_not_node(xas->xa_node))
                        return entry;
@@ -1150,6 +1155,8 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
 
        if (xas_error(xas))
                return NULL;
+       if (xas->xa_index > max)
+               goto max;
 
        if (!xas->xa_node) {
                xas->xa_index = 1;
@@ -1824,6 +1831,17 @@ void *xa_find(struct xarray *xa, unsigned long *indexp,
 }
 EXPORT_SYMBOL(xa_find);
 
+static bool xas_sibling(struct xa_state *xas)
+{
+       struct xa_node *node = xas->xa_node;
+       unsigned long mask;
+
+       if (!node)
+               return false;
+       mask = (XA_CHUNK_SIZE << node->shift) - 1;
+       return (xas->xa_index & mask) > (xas->xa_offset << node->shift);
+}
+
 /**
  * xa_find_after() - Search the XArray for a present entry.
  * @xa: XArray.
@@ -1847,21 +1865,20 @@ void *xa_find_after(struct xarray *xa, unsigned long *indexp,
        XA_STATE(xas, xa, *indexp + 1);
        void *entry;
 
+       if (xas.xa_index == 0)
+               return NULL;
+
        rcu_read_lock();
        for (;;) {
                if ((__force unsigned int)filter < XA_MAX_MARKS)
                        entry = xas_find_marked(&xas, max, filter);
                else
                        entry = xas_find(&xas, max);
-               if (xas.xa_node == XAS_BOUNDS)
+
+               if (xas_invalid(&xas))
                        break;
-               if (xas.xa_shift) {
-                       if (xas.xa_index & ((1UL << xas.xa_shift) - 1))
-                               continue;
-               } else {
-                       if (xas.xa_offset < (xas.xa_index & XA_CHUNK_MASK))
-                               continue;
-               }
+               if (xas_sibling(&xas))
+                       continue;
                if (!xas_retry(&xas, entry))
                        break;
        }