1 files changed, 75 insertions, 0 deletions
diff --git a/sound/core/memory.c b/sound/core/memory.c
new file mode 100644
index 000000000..5d894dc32
--- /dev/null
+++ b/sound/core/memory.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ * 
+ *  Misc memory accessors
+ */
+
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <sound/core.h>
+
+/**
+ * copy_to_user_fromio - copy data from mmio-space to user-space
+ * @dst: the destination pointer on user-space
+ * @src: the source pointer on mmio
+ * @count: the data size to copy in bytes
+ *
+ * Copies the data from mmio-space to user-space.
+ *
+ * Return: Zero if successful, or non-zero on failure.
+ */
+int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
+{
+#if defined(__i386__) || defined(CONFIG_SPARC32)
+	return copy_to_user(dst, (const void __force*)src, count) ? -EFAULT : 0;
+#else
+	char buf[256];
+	while (count) {
+		size_t c = count;
+		if (c > sizeof(buf))
+			c = sizeof(buf);
+		memcpy_fromio(buf, (void __iomem *)src, c);
+		if (copy_to_user(dst, buf, c))
+			return -EFAULT;
+		count -= c;
+		dst += c;
+		src += c;
+	}
+	return 0;
+#endif
+}
+EXPORT_SYMBOL(copy_to_user_fromio);
+
+/**
+ * copy_from_user_toio - copy data from user-space to mmio-space
+ * @dst: the destination pointer on mmio-space
+ * @src: the source pointer on user-space
+ * @count: the data size to copy in bytes
+ *
+ * Copies the data from user-space to mmio-space.
+ *
+ * Return: Zero if successful, or non-zero on failure.
+ */
+int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
+{
+#if defined(__i386__) || defined(CONFIG_SPARC32)
+	return copy_from_user((void __force *)dst, src, count) ? -EFAULT : 0;
+#else
+	char buf[256];
+	while (count) {
+		size_t c = count;
+		if (c > sizeof(buf))
+			c = sizeof(buf);
+		if (copy_from_user(buf, src, c))
+			return -EFAULT;
+		memcpy_toio(dst, buf, c);
+		count -= c;
+		dst += c;
+		src += c;
+	}
+	return 0;
+#endif
+}
+EXPORT_SYMBOL(copy_from_user_toio);