tty: vt: move CSI ECMA handling to a separate function

Similar to previous moves, move also "CSI ..." (i.e. vc_priv == EPecma)
handling to a separate function.

This is the last large move of code out of do_con_trol(). And despite it
is still 151 lines of code (down from 407!), it is now quite easy to
folllow the transitions of the state machine in there. ESnonstd and
ESpalette handling still can be moved away, but it won't improve that
much.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-15-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 139 insertions, 130 deletions

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 7cdd0eb1e423..1c832d04c0dc 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2375,6 +2375,143 @@ static void csi_DEC(struct tty_struct *tty, struct vc_data *vc, u8 c)
 	}
 }
 
+/*
+ * Handle Control Sequence Introducer control characters. That is
+ * "ESC [ parameters char". Parameters are in @vc->vc_par and the char is in
+ * @c here.
+ */
+static void csi_ECMA(struct tty_struct *tty, struct vc_data *vc, u8 c)
+{
+	switch (c) {
+	case 'G':
+	case '`':
+		if (vc->vc_par[0])
+			vc->vc_par[0]--;
+		gotoxy(vc, vc->vc_par[0], vc->state.y);
+		break;
+	case 'A':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
+		break;
+	case 'B':
+	case 'e':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
+		break;
+	case 'C':
+	case 'a':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
+		break;
+	case 'D':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
+		break;
+	case 'E':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
+		break;
+	case 'F':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
+		break;
+	case 'd':
+		if (vc->vc_par[0])
+			vc->vc_par[0]--;
+		gotoxay(vc, vc->state.x ,vc->vc_par[0]);
+		break;
+	case 'H':
+	case 'f':
+		if (vc->vc_par[0])
+			vc->vc_par[0]--;
+		if (vc->vc_par[1])
+			vc->vc_par[1]--;
+		gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
+		break;
+	case 'J':
+		csi_J(vc, vc->vc_par[0]);
+		break;
+	case 'K':
+		csi_K(vc);
+		break;
+	case 'L':
+		csi_L(vc);
+		break;
+	case 'M':
+		csi_M(vc);
+		break;
+	case 'P':
+		csi_P(vc);
+		break;
+	case 'c':
+		if (!vc->vc_par[0])
+			respond_ID(tty);
+		break;
+	case 'g':
+		if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
+			set_bit(vc->state.x, vc->vc_tab_stop);
+		else if (vc->vc_par[0] == 3)
+			bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
+		break;
+	case 'h':
+		csi_hl(vc, true);
+		break;
+	case 'l':
+		csi_hl(vc, false);
+		break;
+	case 'm':
+		csi_m(vc);
+		break;
+	case 'n':
+		if (vc->vc_par[0] == 5)
+			status_report(tty);
+		else if (vc->vc_par[0] == 6)
+			cursor_report(vc, tty);
+		break;
+	case 'q': /* DECLL - but only 3 leds */
+		/* map 0,1,2,3 to 0,1,2,4 */
+		if (vc->vc_par[0] < 4)
+			vt_set_led_state(vc->vc_num,
+				    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
+		break;
+	case 'r':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		if (!vc->vc_par[1])
+			vc->vc_par[1] = vc->vc_rows;
+		/* Minimum allowed region is 2 lines */
+		if (vc->vc_par[0] < vc->vc_par[1] &&
+		    vc->vc_par[1] <= vc->vc_rows) {
+			vc->vc_top = vc->vc_par[0] - 1;
+			vc->vc_bottom = vc->vc_par[1];
+			gotoxay(vc, 0, 0);
+		}
+		break;
+	case 's':
+		save_cur(vc);
+		break;
+	case 'u':
+		restore_cur(vc);
+		break;
+	case 'X':
+		csi_X(vc);
+		break;
+	case '@':
+		csi_at(vc, vc->vc_par[0]);
+		break;
+	case ']':
+		csi_RSB(vc);
+		break;
+	}
+
+}
+
 /* console_lock is held */
 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, u8 c)
 {
@@ -2470,139 +2607,11 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, u8 c)
 			csi_DEC(tty, vc, c);
 			return;
 		case EPecma:
-			break;
-		default:
-			return;
-		}
-
-		switch(c) {
-		case 'G':
-		case '`':
-			if (vc->vc_par[0])
-				vc->vc_par[0]--;
-			gotoxy(vc, vc->vc_par[0], vc->state.y);
-			return;
-		case 'A':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
-			return;
-		case 'B':
-		case 'e':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
-			return;
-		case 'C':
-		case 'a':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
-			return;
-		case 'D':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
-			return;
-		case 'E':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
+			csi_ECMA(tty, vc, c);
 			return;
-		case 'F':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
-			return;
-		case 'd':
-			if (vc->vc_par[0])
-				vc->vc_par[0]--;
-			gotoxay(vc, vc->state.x ,vc->vc_par[0]);
-			return;
-		case 'H':
-		case 'f':
-			if (vc->vc_par[0])
-				vc->vc_par[0]--;
-			if (vc->vc_par[1])
-				vc->vc_par[1]--;
-			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
-			return;
-		case 'J':
-			csi_J(vc, vc->vc_par[0]);
-			return;
-		case 'K':
-			csi_K(vc);
-			return;
-		case 'L':
-			csi_L(vc);
-			return;
-		case 'M':
-			csi_M(vc);
-			return;
-		case 'P':
-			csi_P(vc);
-			return;
-		case 'c':
-			if (!vc->vc_par[0])
-				respond_ID(tty);
-			return;
-		case 'g':
-			if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
-				set_bit(vc->state.x, vc->vc_tab_stop);
-			else if (vc->vc_par[0] == 3)
-				bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
-			return;
-		case 'h':
-			csi_hl(vc, true);
-			return;
-		case 'l':
-			csi_hl(vc, false);
-			return;
-		case 'm':
-			csi_m(vc);
-			return;
-		case 'n':
-			if (vc->vc_par[0] == 5)
-				status_report(tty);
-			else if (vc->vc_par[0] == 6)
-				cursor_report(vc, tty);
-			return;
-		case 'q': /* DECLL - but only 3 leds */
-			/* map 0,1,2,3 to 0,1,2,4 */
-			if (vc->vc_par[0] < 4)
-				vt_set_led_state(vc->vc_num,
-					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
-			return;
-		case 'r':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			if (!vc->vc_par[1])
-				vc->vc_par[1] = vc->vc_rows;
-			/* Minimum allowed region is 2 lines */
-			if (vc->vc_par[0] < vc->vc_par[1] &&
-			    vc->vc_par[1] <= vc->vc_rows) {
-				vc->vc_top = vc->vc_par[0] - 1;
-				vc->vc_bottom = vc->vc_par[1];
-				gotoxay(vc, 0, 0);
-			}
-			return;
-		case 's':
-			save_cur(vc);
-			return;
-		case 'u':
-			restore_cur(vc);
-			return;
-		case 'X':
-			csi_X(vc);
-			return;
-		case '@':
-			csi_at(vc, vc->vc_par[0]);
-			return;
-		case ']':
-			csi_RSB(vc);
+		default:
 			return;
 		}
-		return;
 	case EScsiignore:
 		if (c >= ASCII_CSI_IGNORE_FIRST && c <= ASCII_CSI_IGNORE_LAST)
 			return;