1 files changed, 68 insertions, 0 deletions

diff --git a/lib/string_helpers.c b/lib/string_helpers.c
new file mode 100644
index 000000000000..ab431d4cc970
--- /dev/null
+++ b/lib/string_helpers.c
@@ -0,0 +1,68 @@
+/*
+ * 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 unsigned int divisor[] = {
+                [STRING_UNITS_10] = 1000,
+                [STRING_UNITS_2] = 1024,
+        };
+        int i, j;
+        u64 remainder = 0, sf_cap;
+        char tmp[8];
+
+        tmp[0] = '\0';
+        i = 0;
+        if (size >= divisor[units]) {
+                while (size >= divisor[units] && units_str[units][i]) {
+                        remainder = do_div(size, divisor[units]);
+                        i++;
+                }
+
+                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);