tty: vt, separate T.416 high colors handler

The code with T.416 high colors handling is flushed to the right and
hard to read. Move the code to a separate function and remove code
duplication for foreground & background colors.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 37 insertions, 48 deletions

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 6e12d9c0ea41..da49f5cfa654 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1284,6 +1284,40 @@ static void rgb_background(struct vc_data *vc, struct rgb c)
                 | (c.r&0x80) >> 1 | (c.g&0x80) >> 2 | (c.b&0x80) >> 3;
 }
 
+/*
+ * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
+ * and thus need to be detected and ignored by hand. Strictly speaking, that
+ * standard also wants : rather than ; as separators, contrary to ECMA-48, but
+ * no one produces such codes and almost no one accepts them.
+ *
+ * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
+ * supporting them.
+ */
+static int vc_t416_color(struct vc_data *vc, int i,
+                void(*set_color)(struct vc_data *vc, struct rgb c))
+{
+        i++;
+        if (i > vc->vc_npar)
+                return i;
+
+        if (vc->vc_par[i] == 5 && i < vc->vc_npar) {
+                /* 256 colours -- ubiquitous */
+                i++;
+                set_color(vc, rgb_from_256(vc->vc_par[i]));
+        } else if (vc->vc_par[i] == 2 && i <= vc->vc_npar + 3) {
+                /* 24 bit -- extremely rare */
+                struct rgb c = {
+                        .r = vc->vc_par[i + 1],
+                        .g = vc->vc_par[i + 2],
+                        .b = vc->vc_par[i + 3],
+                };
+                set_color(vc, c);
+                i += 3;
+        }
+
+        return i;
+}
+
 /* console_lock is held */
 static void csi_m(struct vc_data *vc)
 {
@@ -1355,56 +1389,11 @@ static void csi_m(struct vc_data *vc)
                         case 27:
                                 vc->vc_reverse = 0;
                                 break;
-                        case 38: /* ITU T.416
-                                  * Higher colour modes.
-                                  * They break the usual properties of SGR codes
-                                  * and thus need to be detected and ignored by
-                                  * hand.  Strictly speaking, that standard also
-                                  * wants : rather than ; as separators, contrary
-                                  * to ECMA-48, but no one produces such codes
-                                  * and almost no one accepts them.
-                                  */
-                                i++;
-                                if (i > vc->vc_npar)
-                                        break;
-                                if (vc->vc_par[i] == 5 &&  /* 256 colours */
-                                    i < vc->vc_npar) {     /* ubiquitous */
-                                        i++;
-                                        rgb_foreground(vc,
-                                                rgb_from_256(vc->vc_par[i]));
-                                } else if (vc->vc_par[i] == 2 &&  /* 24 bit */
-                                           i <= vc->vc_npar + 3) {/* extremely rare */
-                                        struct rgb c = {
-                                                .r = vc->vc_par[i + 1],
-                                                .g = vc->vc_par[i + 2],
-                                                .b = vc->vc_par[i + 3],
-                                        };
-                                        rgb_foreground(vc, c);
-                                        i += 3;
-                                }
-                                /* Subcommands 3 (CMY) and 4 (CMYK) are so insane
-                                 * there's no point in supporting them.
-                                 */
+                        case 38:
+                                i = vc_t416_color(vc, i, rgb_foreground);
                                 break;
                         case 48:
-                                i++;
-                                if (i > vc->vc_npar)
-                                        break;
-                                if (vc->vc_par[i] == 5 &&  /* 256 colours */
-                                    i < vc->vc_npar) {
-                                        i++;
-                                        rgb_background(vc,
-                                                rgb_from_256(vc->vc_par[i]));
-                                } else if (vc->vc_par[i] == 2 && /* 24 bit */
-                                           i <= vc->vc_npar + 3) {
-                                        struct rgb c = {
-                                                .r = vc->vc_par[i + 1],
-                                                .g = vc->vc_par[i + 2],
-                                                .b = vc->vc_par[i + 3],
-                                        };
-                                        rgb_background(vc, c);
-                                        i += 3;
-                                }
+                                i = vc_t416_color(vc, i, rgb_background);
                                 break;
                         case 39:
                                 vc->vc_color = (vc->vc_def_color & 0x0f) | (vc->vc_color & 0xf0);