[PATCH 12/16] vc_screen: extract vcs_read_buf_uni

From: Jiri Slaby
Date: Tue Aug 18 2020 - 04:58:03 EST


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@xxxxxxx>
---
drivers/tty/vt/vc_screen.c | 49 +++++++++++++++++++++++---------------
1 file changed, 30 insertions(+), 19 deletions(-)

diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
index 8ebb6724a804..91d2e0148a67 100644
--- 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;
--
2.28.0