These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / lib / sort.c

diff --git a/kernel/lib/sort.c b/kernel/lib/sort.c
index 43c9fe7..fc20df4 100644 (file)
--- a/kernel/lib/sort.c
+++ b/kernel/lib/sort.c
@@ -8,6 +8,12 @@
 #include <linux/export.h>
 #include <linux/sort.h>
 
+static int alignment_ok(const void *base, int align)
+{
+       return IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
+               ((unsigned long)base & (align - 1)) == 0;
+}
+
 static void u32_swap(void *a, void *b, int size)
 {
        u32 t = *(u32 *)a;
@@ -15,6 +21,13 @@ static void u32_swap(void *a, void *b, int size)
        *(u32 *)b = t;
 }
 
+static void u64_swap(void *a, void *b, int size)
+{
+       u64 t = *(u64 *)a;
+       *(u64 *)a = *(u64 *)b;
+       *(u64 *)b = t;
+}
+
 static void generic_swap(void *a, void *b, int size)
 {
        char t;
@@ -50,8 +63,14 @@ void sort(void *base, size_t num, size_t size,
        /* pre-scale counters for performance */
        int i = (num/2 - 1) * size, n = num * size, c, r;
 
-       if (!swap_func)
-               swap_func = (size == 4 ? u32_swap : generic_swap);
+       if (!swap_func) {
+               if (size == 4 && alignment_ok(base, 4))
+                       swap_func = u32_swap;
+               else if (size == 8 && alignment_ok(base, 8))
+                       swap_func = u64_swap;
+               else
+                       swap_func = generic_swap;
+       }
 
        /* heapify */
        for ( ; i >= 0; i -= size) {