iommu/amd: Use swiotlb in passthrough mode
[linux-2.6-block.git] / lib / string_helpers.c
index 8f8c4417f22865d9ffb274700540b37f1a17bd93..c98ae818eb4eed802119133ca9d1c809d6b9f155 100644 (file)
@@ -4,6 +4,7 @@
  * Copyright 31 August 2008 James Bottomley
  * Copyright (C) 2013, Intel Corporation
  */
+#include <linux/bug.h>
 #include <linux/kernel.h>
 #include <linux/math64.h>
 #include <linux/export.h>
@@ -14,7 +15,8 @@
 
 /**
  * string_get_size - get the size in the specified units
- * @size:      The size to be converted
+ * @size:      The size to be converted in blocks
+ * @blk_size:  Size of the block (use 1 for size in bytes)
  * @units:     units to use (powers of 1000 or 1024)
  * @buf:       buffer to format to
  * @len:       length of buffer
  * at least 9 bytes and will always be zero terminated.
  *
  */
-void string_get_size(u64 size, const enum string_size_units units,
+void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
                     char *buf, int len)
 {
        static const char *const units_10[] = {
-               "B", "kB", "MB", "GB", "TB", "PB", "EB"
+               "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
        };
        static const char *const units_2[] = {
-               "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"
+               "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"
        };
        static const char *const *const units_str[] = {
                [STRING_UNITS_10] = units_10,
@@ -42,31 +44,57 @@ void string_get_size(u64 size, const enum string_size_units units,
                [STRING_UNITS_2] = 1024,
        };
        int i, j;
-       u32 remainder = 0, sf_cap;
+       u32 remainder = 0, sf_cap, exp;
        char tmp[8];
+       const char *unit;
 
        tmp[0] = '\0';
        i = 0;
-       if (size >= divisor[units]) {
-               while (size >= divisor[units]) {
-                       remainder = do_div(size, divisor[units]);
-                       i++;
-               }
+       if (!size)
+               goto out;
 
-               sf_cap = size;
-               for (j = 0; sf_cap*10 < 1000; j++)
-                       sf_cap *= 10;
+       while (blk_size >= divisor[units]) {
+               remainder = do_div(blk_size, divisor[units]);
+               i++;
+       }
 
-               if (j) {
-                       remainder *= 1000;
-                       remainder /= divisor[units];
-                       snprintf(tmp, sizeof(tmp), ".%03u", remainder);
-                       tmp[j+1] = '\0';
-               }
+       exp = divisor[units] / (u32)blk_size;
+       if (size >= exp) {
+               remainder = do_div(size, divisor[units]);
+               remainder *= blk_size;
+               i++;
+       } else {
+               remainder *= size;
+       }
+
+       size *= blk_size;
+       size += remainder / divisor[units];
+       remainder %= divisor[units];
+
+       while (size >= divisor[units]) {
+               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;
+               remainder /= divisor[units];
+               snprintf(tmp, sizeof(tmp), ".%03u", remainder);
+               tmp[j+1] = '\0';
+       }
+
+ out:
+       if (i >= ARRAY_SIZE(units_2))
+               unit = "UNK";
+       else
+               unit = units_str[units][i];
+
        snprintf(buf, len, "%u%s %s", (u32)size,
-                tmp, units_str[units][i]);
+                tmp, unit);
 }
 EXPORT_SYMBOL(string_get_size);
 
@@ -239,29 +267,21 @@ int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
 }
 EXPORT_SYMBOL(string_unescape);
 
-static int escape_passthrough(unsigned char c, char **dst, size_t *osz)
+static bool escape_passthrough(unsigned char c, char **dst, char *end)
 {
        char *out = *dst;
 
-       if (*osz < 1)
-               return -ENOMEM;
-
-       *out++ = c;
-
-       *dst = out;
-       *osz -= 1;
-
-       return 1;
+       if (out < end)
+               *out = c;
+       *dst = out + 1;
+       return true;
 }
 
-static int escape_space(unsigned char c, char **dst, size_t *osz)
+static bool escape_space(unsigned char c, char **dst, char *end)
 {
        char *out = *dst;
        unsigned char to;
 
-       if (*osz < 2)
-               return -ENOMEM;
-
        switch (c) {
        case '\n':
                to = 'n';
@@ -279,26 +299,25 @@ static int escape_space(unsigned char c, char **dst, size_t *osz)
                to = 'f';
                break;
        default:
-               return 0;
+               return false;
        }
 
-       *out++ = '\\';
-       *out++ = to;
+       if (out < end)
+               *out = '\\';
+       ++out;
+       if (out < end)
+               *out = to;
+       ++out;
 
        *dst = out;
-       *osz -= 2;
-
-       return 1;
+       return true;
 }
 
-static int escape_special(unsigned char c, char **dst, size_t *osz)
+static bool escape_special(unsigned char c, char **dst, char *end)
 {
        char *out = *dst;
        unsigned char to;
 
-       if (*osz < 2)
-               return -ENOMEM;
-
        switch (c) {
        case '\\':
                to = '\\';
@@ -310,71 +329,78 @@ static int escape_special(unsigned char c, char **dst, size_t *osz)
                to = 'e';
                break;
        default:
-               return 0;
+               return false;
        }
 
-       *out++ = '\\';
-       *out++ = to;
+       if (out < end)
+               *out = '\\';
+       ++out;
+       if (out < end)
+               *out = to;
+       ++out;
 
        *dst = out;
-       *osz -= 2;
-
-       return 1;
+       return true;
 }
 
-static int escape_null(unsigned char c, char **dst, size_t *osz)
+static bool escape_null(unsigned char c, char **dst, char *end)
 {
        char *out = *dst;
 
-       if (*osz < 2)
-               return -ENOMEM;
-
        if (c)
-               return 0;
+               return false;
 
-       *out++ = '\\';
-       *out++ = '0';
+       if (out < end)
+               *out = '\\';
+       ++out;
+       if (out < end)
+               *out = '0';
+       ++out;
 
        *dst = out;
-       *osz -= 2;
-
-       return 1;
+       return true;
 }
 
-static int escape_octal(unsigned char c, char **dst, size_t *osz)
+static bool escape_octal(unsigned char c, char **dst, char *end)
 {
        char *out = *dst;
 
-       if (*osz < 4)
-               return -ENOMEM;
-
-       *out++ = '\\';
-       *out++ = ((c >> 6) & 0x07) + '0';
-       *out++ = ((c >> 3) & 0x07) + '0';
-       *out++ = ((c >> 0) & 0x07) + '0';
+       if (out < end)
+               *out = '\\';
+       ++out;
+       if (out < end)
+               *out = ((c >> 6) & 0x07) + '0';
+       ++out;
+       if (out < end)
+               *out = ((c >> 3) & 0x07) + '0';
+       ++out;
+       if (out < end)
+               *out = ((c >> 0) & 0x07) + '0';
+       ++out;
 
        *dst = out;
-       *osz -= 4;
-
-       return 1;
+       return true;
 }
 
-static int escape_hex(unsigned char c, char **dst, size_t *osz)
+static bool escape_hex(unsigned char c, char **dst, char *end)
 {
        char *out = *dst;
 
-       if (*osz < 4)
-               return -ENOMEM;
-
-       *out++ = '\\';
-       *out++ = 'x';
-       *out++ = hex_asc_hi(c);
-       *out++ = hex_asc_lo(c);
+       if (out < end)
+               *out = '\\';
+       ++out;
+       if (out < end)
+               *out = 'x';
+       ++out;
+       if (out < end)
+               *out = hex_asc_hi(c);
+       ++out;
+       if (out < end)
+               *out = hex_asc_lo(c);
+       ++out;
 
        *dst = out;
-       *osz -= 4;
-
-       return 1;
+       return true;
 }
 
 /**
@@ -426,19 +452,17 @@ static int escape_hex(unsigned char c, char **dst, size_t *osz)
  * it if needs.
  *
  * Return:
- * The amount of the characters processed to the destination buffer, or
- * %-ENOMEM if the size of buffer is not enough to put an escaped character is
- * returned.
- *
- * Even in the case of error @dst pointer will be updated to point to the byte
- * after the last processed character.
+ * The total size of the escaped output that would be generated for
+ * the given input and flags. To check whether the output was
+ * truncated, compare the return value to osz. There is room left in
+ * dst for a '\0' terminator if and only if ret < osz.
  */
-int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
+int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
                      unsigned int flags, const char *esc)
 {
-       char *out = *dst, *p = out;
+       char *p = dst;
+       char *end = p + osz;
        bool is_dict = esc && *esc;
-       int ret = 0;
 
        while (isz--) {
                unsigned char c = *src++;
@@ -458,55 +482,26 @@ int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
                    (is_dict && !strchr(esc, c))) {
                        /* do nothing */
                } else {
-                       if (flags & ESCAPE_SPACE) {
-                               ret = escape_space(c, &p, &osz);
-                               if (ret < 0)
-                                       break;
-                               if (ret > 0)
-                                       continue;
-                       }
-
-                       if (flags & ESCAPE_SPECIAL) {
-                               ret = escape_special(c, &p, &osz);
-                               if (ret < 0)
-                                       break;
-                               if (ret > 0)
-                                       continue;
-                       }
-
-                       if (flags & ESCAPE_NULL) {
-                               ret = escape_null(c, &p, &osz);
-                               if (ret < 0)
-                                       break;
-                               if (ret > 0)
-                                       continue;
-                       }
+                       if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
+                               continue;
+
+                       if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
+                               continue;
+
+                       if (flags & ESCAPE_NULL && escape_null(c, &p, end))
+                               continue;
 
                        /* ESCAPE_OCTAL and ESCAPE_HEX always go last */
-                       if (flags & ESCAPE_OCTAL) {
-                               ret = escape_octal(c, &p, &osz);
-                               if (ret < 0)
-                                       break;
+                       if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
                                continue;
-                       }
-                       if (flags & ESCAPE_HEX) {
-                               ret = escape_hex(c, &p, &osz);
-                               if (ret < 0)
-                                       break;
+
+                       if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
                                continue;
-                       }
                }
 
-               ret = escape_passthrough(c, &p, &osz);
-               if (ret < 0)
-                       break;
+               escape_passthrough(c, &p, end);
        }
 
-       *dst = p;
-
-       if (ret < 0)
-               return ret;
-
-       return p - out;
+       return p - dst;
 }
 EXPORT_SYMBOL(string_escape_mem);