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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/hexagon/mm/uaccess.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/hexagon/mm/uaccess.c')
-rw-r--r--arch/hexagon/mm/uaccess.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/hexagon/mm/uaccess.c b/arch/hexagon/mm/uaccess.c
new file mode 100644
index 0000000000..650bca92f0
--- /dev/null
+++ b/arch/hexagon/mm/uaccess.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
+ */
+
+/*
+ * Support for user memory access from kernel. This will
+ * probably be inlined for performance at some point, but
+ * for ease of debug, and to a lesser degree for code size,
+ * we implement here as subroutines.
+ */
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/pgtable.h>
+
+/*
+ * For clear_user(), exploit previously defined copy_to_user function
+ * and the fact that we've got a handy zero page defined in kernel/head.S
+ *
+ * dczero here would be even faster.
+ */
+__kernel_size_t __clear_user_hexagon(void __user *dest, unsigned long count)
+{
+ long uncleared;
+
+ while (count > PAGE_SIZE) {
+ uncleared = raw_copy_to_user(dest, &empty_zero_page, PAGE_SIZE);
+ if (uncleared)
+ return count - (PAGE_SIZE - uncleared);
+ count -= PAGE_SIZE;
+ dest += PAGE_SIZE;
+ }
+ if (count)
+ count = raw_copy_to_user(dest, &empty_zero_page, count);
+
+ return count;
+}
+
+unsigned long clear_user_hexagon(void __user *dest, unsigned long count)
+{
+ if (!access_ok(dest, count))
+ return count;
+ else
+ return __clear_user_hexagon(dest, count);
+}