ieee1394: shrink csr1212_new_string_descriptor_leaf

Make unnecessarily generic code specific and thus simpler.
Shrink a lookup table from 128 to 16 bytes.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --git a/drivers/ieee1394/csr1212.c b/drivers/ieee1394/csr1212.c
index 4887e4895fd7299a3bd2b7295bfe173626ce148d..63bf11eb4d312c4d976b9f0a4cd25333a22b4f1d 100644 (file)
--- a/drivers/ieee1394/csr1212.c
+++ b/drivers/ieee1394/csr1212.c
@@ -388,101 +388,70 @@ csr1212_new_descriptor_leaf(u8 dtype, u32 specifier_id,
        CSR1212_DESCRIPTOR_LEAF_SET_TYPE(kv, dtype);
        CSR1212_DESCRIPTOR_LEAF_SET_SPECIFIER_ID(kv, specifier_id);
 
-       if (data) {
+       if (data)
                memcpy(CSR1212_DESCRIPTOR_LEAF_DATA(kv), data, data_len);
-       }
-
-       return kv;
-}
-
-#define CSR1212_TEXTUAL_DESCRIPTOR_LEAF_SET_WIDTH(kv, width) \
-       ((kv)->value.leaf.data[1] = \
-        ((kv)->value.leaf.data[1] & \
-         cpu_to_be32(~(CSR1212_TEXTUAL_DESCRIPTOR_LEAF_WIDTH_MASK << \
-                       CSR1212_TEXTUAL_DESCRIPTOR_LEAF_WIDTH_SHIFT))) | \
-        cpu_to_be32(((width) & CSR1212_TEXTUAL_DESCRIPTOR_LEAF_WIDTH_MASK) << \
-                    CSR1212_TEXTUAL_DESCRIPTOR_LEAF_WIDTH_SHIFT))
-
-#define CSR1212_TEXTUAL_DESCRIPTOR_LEAF_SET_CHAR_SET(kv, char_set) \
-       ((kv)->value.leaf.data[1] = \
-        ((kv)->value.leaf.data[1] & \
-         cpu_to_be32(~(CSR1212_TEXTUAL_DESCRIPTOR_LEAF_CHAR_SET_MASK << \
-                       CSR1212_TEXTUAL_DESCRIPTOR_LEAF_CHAR_SET_SHIFT))) | \
-        cpu_to_be32(((char_set) & \
-                     CSR1212_TEXTUAL_DESCRIPTOR_LEAF_CHAR_SET_MASK) << \
-                    CSR1212_TEXTUAL_DESCRIPTOR_LEAF_CHAR_SET_SHIFT))
-
-#define CSR1212_TEXTUAL_DESCRIPTOR_LEAF_SET_LANGUAGE(kv, language) \
-       ((kv)->value.leaf.data[1] = \
-        ((kv)->value.leaf.data[1] & \
-         cpu_to_be32(~(CSR1212_TEXTUAL_DESCRIPTOR_LEAF_LANGUAGE_MASK))) | \
-        cpu_to_be32(((language) & \
-                     CSR1212_TEXTUAL_DESCRIPTOR_LEAF_LANGUAGE_MASK)))
-
-static struct csr1212_keyval *
-csr1212_new_textual_descriptor_leaf(u8 cwidth, u16 cset, u16 language,
-                                   const void *data, size_t data_len)
-{
-       struct csr1212_keyval *kv;
-       char *lstr;
-
-       kv = csr1212_new_descriptor_leaf(0, 0, NULL, data_len +
-                                        CSR1212_TEXTUAL_DESCRIPTOR_LEAF_OVERHEAD);
-       if (!kv)
-               return NULL;
-
-       CSR1212_TEXTUAL_DESCRIPTOR_LEAF_SET_WIDTH(kv, cwidth);
-       CSR1212_TEXTUAL_DESCRIPTOR_LEAF_SET_CHAR_SET(kv, cset);
-       CSR1212_TEXTUAL_DESCRIPTOR_LEAF_SET_LANGUAGE(kv, language);
-
-       lstr = (char*)CSR1212_TEXTUAL_DESCRIPTOR_LEAF_DATA(kv);
-
-       /* make sure last quadlet is zeroed out */
-       *((u32*)&(lstr[(data_len - 1) & ~0x3])) = 0;
-
-       /* don't copy the NUL terminator */
-       memcpy(lstr, data, data_len);
 
        return kv;
 }
 
+/* Check if string conforms to minimal ASCII as per IEEE 1212 clause 7.4 */
 static int csr1212_check_minimal_ascii(const char *s)
 {
        static const char minimal_ascii_table[] = {
-               0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07,
-               0x00, 0x00, 0x0a, 0x00, 0x0C, 0x0D, 0x00, 0x00,
-               0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-               0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-               0x20, 0x21, 0x22, 0x00, 0x00, 0x25, 0x26, 0x27,
-               0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
-               0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
-               0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
-               0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
-               0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
-               0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
-               0x58, 0x59, 0x5a, 0x00, 0x00, 0x00, 0x00, 0x5f,
-               0x00, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
-               0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
-               0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
-               0x78, 0x79, 0x7a, 0x00, 0x00, 0x00, 0x00, 0x00,
+                                       /*  1   2   4   8  16  32  64  128 */
+               128,                    /* --, --, --, --, --, --, --, 07, */
+               4 + 16 + 32,            /* --, --, 0a, --, 0C, 0D, --, --, */
+               0,                      /* --, --, --, --, --, --, --, --, */
+               0,                      /* --, --, --, --, --, --, --, --, */
+               255 - 8 - 16,           /* 20, 21, 22, --, --, 25, 26, 27, */
+               255,                    /* 28, 29, 2a, 2b, 2c, 2d, 2e, 2f, */
+               255,                    /* 30, 31, 32, 33, 34, 35, 36, 37, */
+               255,                    /* 38, 39, 3a, 3b, 3c, 3d, 3e, 3f, */
+               255,                    /* 40, 41, 42, 43, 44, 45, 46, 47, */
+               255,                    /* 48, 49, 4a, 4b, 4c, 4d, 4e, 4f, */
+               255,                    /* 50, 51, 52, 53, 54, 55, 56, 57, */
+               1 + 2 + 4 + 128,        /* 58, 59, 5a, --, --, --, --, 5f, */
+               255 - 1,                /* --, 61, 62, 63, 64, 65, 66, 67, */
+               255,                    /* 68, 69, 6a, 6b, 6c, 6d, 6e, 6f, */
+               255,                    /* 70, 71, 72, 73, 74, 75, 76, 77, */
+               1 + 2 + 4,              /* 78, 79, 7a, --, --, --, --, --, */
        };
+       int i, j;
+
        for (; *s; s++) {
-               if (minimal_ascii_table[*s & 0x7F] != *s)
-                       return -1; /* failed */
+               i = *s >> 3;            /*  i = *s / 8;         */
+               j = 1 << (*s & 3);      /*  j = 1 << (*s % 8);  */
+
+               if (i >= ARRAY_SIZE(minimal_ascii_table) ||
+                   !(minimal_ascii_table[i] & j))
+                       return -EINVAL;
        }
-       /* String conforms to minimal-ascii, as specified by IEEE 1212,
-        * par. 7.4 */
        return 0;
 }
 
+/* IEEE 1212 clause 7.5.4.1 textual descriptors (English, minimal ASCII) */
 struct csr1212_keyval *csr1212_new_string_descriptor_leaf(const char *s)
 {
-       /* Check if string conform to minimal_ascii format */
-       if (csr1212_check_minimal_ascii(s))
+       struct csr1212_keyval *kv;
+       u32 *text;
+       size_t str_len, quads;
+
+       if (!s || !*s || csr1212_check_minimal_ascii(s))
+               return NULL;
+
+       str_len = strlen(s);
+       quads = bytes_to_quads(str_len);
+       kv = csr1212_new_descriptor_leaf(0, 0, NULL, quads_to_bytes(quads) +
+                                     CSR1212_TEXTUAL_DESCRIPTOR_LEAF_OVERHEAD);
+       if (!kv)
                return NULL;
 
-       /* IEEE 1212, par. 7.5.4.1  Textual descriptors (minimal ASCII) */
-       return csr1212_new_textual_descriptor_leaf(0, 0, 0, s, strlen(s));
+       kv->value.leaf.data[1] = 0;     /* width, character_set, language */
+       text = CSR1212_TEXTUAL_DESCRIPTOR_LEAF_DATA(kv);
+       text[quads - 1] = 0;            /* padding */
+       memcpy(text, s, str_len);
+
+       return kv;
 }