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-rw-r--r--lib/string_helpers.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
new file mode 100644
index 000000000000..8347925030ff
--- /dev/null
+++ b/lib/string_helpers.c
@@ -0,0 +1,64 @@
+/*
+ * Helpers for formatting and printing strings
+ *
+ * Copyright 31 August 2008 James Bottomley
+ */
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/string_helpers.h>
+
+/**
+ * string_get_size - get the size in the specified units
+ * @size:	The size to be converted
+ * @units:	units to use (powers of 1000 or 1024)
+ * @buf:	buffer to format to
+ * @len:	length of buffer
+ *
+ * This function returns a string formatted to 3 significant figures
+ * giving the size in the required units.  Returns 0 on success or
+ * error on failure.  @buf is always zero terminated.
+ *
+ */
+int string_get_size(u64 size, const enum string_size_units units,
+		    char *buf, int len)
+{
+	const char *units_10[] = { "B", "KB", "MB", "GB", "TB", "PB",
+				   "EB", "ZB", "YB", NULL};
+	const char *units_2[] = {"B", "KiB", "MiB", "GiB", "TiB", "PiB",
+				 "EiB", "ZiB", "YiB", NULL };
+	const char **units_str[] = {
+		[STRING_UNITS_10] =  units_10,
+		[STRING_UNITS_2] = units_2,
+	};
+	const int divisor[] = {
+		[STRING_UNITS_10] = 1000,
+		[STRING_UNITS_2] = 1024,
+	};
+	int i, j;
+	u64 remainder = 0, sf_cap;
+	char tmp[8];
+
+	tmp[0] = '\0';
+
+	for (i = 0; size > divisor[units] && units_str[units][i]; i++)
+		remainder = do_div(size, divisor[units]);
+
+	sf_cap = size;
+	for (j = 0; sf_cap*10 < 1000; j++)
+		sf_cap *= 10;
+
+	if (j) {
+		remainder *= 1000;
+		do_div(remainder, divisor[units]);
+		snprintf(tmp, sizeof(tmp), ".%03lld",
+			 (unsigned long long)remainder);
+		tmp[j+1] = '\0';
+	}
+
+	snprintf(buf, len, "%lld%s%s", (unsigned long long)size,
+		 tmp, units_str[units][i]);
+
+	return 0;
+}
+EXPORT_SYMBOL(string_get_size);