vc_screen: extract vcs_read_buf_uni

The same as making write more readable, extract unicode handling from
vcs_read. The other two cases (w/ and w/o attributes) will follow.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200818085706.12163-12-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
index 8ebb672..91d2e01 100644 (file)
--- a/drivers/tty/vt/vc_screen.c
+++ b/drivers/tty/vt/vc_screen.c
@@ -249,6 +249,33 @@ static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
        return fixed_size_llseek(file, offset, orig, size);
 }
 
+static int vcs_read_buf_uni(struct vc_data *vc, char *con_buf,
+               unsigned int pos, unsigned int count, bool viewed)
+{
+       unsigned int nr, row, col, maxcol = vc->vc_cols;
+       int ret;
+
+       ret = vc_uniscr_check(vc);
+       if (ret)
+               return ret;
+
+       pos /= 4;
+       row = pos / maxcol;
+       col = pos % maxcol;
+       nr = maxcol - col;
+       do {
+               if (nr > count / 4)
+                       nr = count / 4;
+               vc_uniscr_copy_line(vc, con_buf, viewed, row, col, nr);
+               con_buf += nr * 4;
+               count -= nr * 4;
+               row++;
+               col = 0;
+               nr = maxcol;
+       } while (count);
+
+       return 0;
+}
 
 static ssize_t
 vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
@@ -257,7 +284,7 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
        struct vc_data *vc;
        struct vcs_poll_data *poll;
        u16 *org;
-       unsigned int read, row, col, maxcol;
+       unsigned int read, col, maxcol;
        ssize_t ret;
        char *con_buf;
        loff_t pos;
@@ -327,26 +354,10 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
                orig_count = this_round;
                maxcol = vc->vc_cols;
                if (uni_mode) {
-                       unsigned int nr;
-
-                       ret = vc_uniscr_check(vc);
+                       ret = vcs_read_buf_uni(vc, con_buf, pos, this_round,
+                                       viewed);
                        if (ret)
                                break;
-                       p /= 4;
-                       row = p / vc->vc_cols;
-                       col = p % maxcol;
-                       nr = maxcol - col;
-                       do {
-                               if (nr > this_round/4)
-                                       nr = this_round/4;
-                               vc_uniscr_copy_line(vc, con_buf0, viewed,
-                                                   row, col, nr);
-                               con_buf0 += nr * 4;
-                               this_round -= nr * 4;
-                               row++;
-                               col = 0;
-                               nr = maxcol;
-                       } while (this_round);
                } else if (!attr) {
                        org = screen_pos(vc, p, viewed);
                        col = p % maxcol;