@@ -4279,6 +4279,44 @@ void vcs_scr_updated(struct vc_data *vc)
notify_update(vc);
}
+void vc_scrolldelta_helper(struct vc_data *c, int lines,
+ unsigned int rolled_over, void *base, unsigned int size)
+{
+ unsigned long ubase = (unsigned long)base;
+ int margin = c->vc_size_row * 4;
+ int ul, we, p, st;
+
+ /* Turn scrollback off */
+ if (!lines) {
+ c->vc_visible_origin = c->vc_origin;
+ return;
+ }
+
+ /* Do we have already enough to allow jumping from 0 to the end? */
+ if (rolled_over > (c->vc_scr_end - ubase) + margin) {
+ ul = c->vc_scr_end - ubase;
+ we = rolled_over + c->vc_size_row;
+ } else {
+ ul = 0;
+ we = size;
+ }
+
+ p = (c->vc_visible_origin - ubase - ul + we) % we +
+ lines * c->vc_size_row;
+ st = (c->vc_origin - ubase - ul + we) % we;
+
+ /* Only a little piece would be left? Show all incl. the piece! */
+ if (st < 2 * margin)
+ margin = 0;
+ if (p < margin)
+ p = 0;
+ if (p > st - margin)
+ p = st;
+
+ c->vc_visible_origin = ubase + (p + ul) % we;
+}
+EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
+
/*
* Visible symbols for modules
*/
@@ -686,8 +686,6 @@ static void
sisusbcon_scrolldelta(struct vc_data *c, int lines)
{
struct sisusb_usb_data *sisusb;
- int margin = c->vc_size_row * 4;
- int ul, we, p, st;
sisusb = sisusb_get_sisusb_lock_and_check(c->vc_num);
if (!sisusb)
@@ -700,39 +698,8 @@ sisusbcon_scrolldelta(struct vc_data *c, int lines)
return;
}
- if (!lines) /* Turn scrollback off */
- c->vc_visible_origin = c->vc_origin;
- else {
-
- if (sisusb->con_rolled_over >
- (c->vc_scr_end - sisusb->scrbuf) + margin) {
-
- ul = c->vc_scr_end - sisusb->scrbuf;
- we = sisusb->con_rolled_over + c->vc_size_row;
-
- } else {
-
- ul = 0;
- we = sisusb->scrbuf_size;
-
- }
-
- p = (c->vc_visible_origin - sisusb->scrbuf - ul + we) % we +
- lines * c->vc_size_row;
-
- st = (c->vc_origin - sisusb->scrbuf - ul + we) % we;
-
- if (st < 2 * margin)
- margin = 0;
-
- if (p < margin)
- p = 0;
-
- if (p > st - margin)
- p = st;
-
- c->vc_visible_origin = sisusb->scrbuf + (p + ul) % we;
- }
+ vc_scrolldelta_helper(c, lines, sisusb->con_rolled_over,
+ (void *)sisusb->scrbuf, sisusb->scrbuf_size);
sisusbcon_set_start_address(sisusb, c);
@@ -332,31 +332,8 @@ static void vgacon_restore_screen(struct vc_data *c)
static void vgacon_scrolldelta(struct vc_data *c, int lines)
{
- if (!lines) /* Turn scrollback off */
- c->vc_visible_origin = c->vc_origin;
- else {
- int margin = c->vc_size_row * 4;
- int ul, we, p, st;
-
- if (vga_rolled_over >
- (c->vc_scr_end - vga_vram_base) + margin) {
- ul = c->vc_scr_end - vga_vram_base;
- we = vga_rolled_over + c->vc_size_row;
- } else {
- ul = 0;
- we = vga_vram_size;
- }
- p = (c->vc_visible_origin - vga_vram_base - ul + we) % we +
- lines * c->vc_size_row;
- st = (c->vc_origin - vga_vram_base - ul + we) % we;
- if (st < 2 * margin)
- margin = 0;
- if (p < margin)
- p = 0;
- if (p > st - margin)
- p = st;
- c->vc_visible_origin = vga_vram_base + (p + ul) % we;
- }
+ vc_scrolldelta_helper(c, lines, vga_rolled_over, (void *)vga_vram_base,
+ vga_vram_size);
vga_set_mem_top(c);
}
#endif /* CONFIG_VGACON_SOFT_SCROLLBACK */
@@ -191,5 +191,7 @@ extern void vt_set_led_state(int console, int leds);
extern void vt_kbd_con_start(int console);
extern void vt_kbd_con_stop(int console);
+void vc_scrolldelta_helper(struct vc_data *c, int lines,
+ unsigned int rolled_over, void *_base, unsigned int size);
#endif /* _VT_KERN_H */
This is a note to let you know that I've just added the patch titled tty: vgacon+sisusb, move scrolldelta to a common helper to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. From 35cc56f9a30480c8a0cca809cf341614a2144758 Mon Sep 17 00:00:00 2001 From: Jiri Slaby <jslaby@suse.cz> Date: Mon, 3 Oct 2016 11:18:35 +0200 Subject: tty: vgacon+sisusb, move scrolldelta to a common helper The code is mirrorred in scrolldelta implementations of both vgacon and sisusb. Let's move the code to a separate helper where we will perform a common cleanup and further changes. While we are moving the code, make it linear and save one indentation level. This is done by returning from the "!lines" then-branch immediatelly. This allows flushing the else-branch 1 level to the left, obviously. Few more new lines and comments were added too. And do not forget to export the helper function given sisusb can be built as module. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Thomas Winischhofer <thomas@winischhofer.net> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: <linux-fbdev@vger.kernel.org> Cc: <linux-usb@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/tty/vt/vt.c | 38 +++++++++++++++++++++++++++++++++ drivers/usb/misc/sisusbvga/sisusb_con.c | 37 ++------------------------------ drivers/video/console/vgacon.c | 27 ++--------------------- include/linux/vt_kern.h | 2 ++ 4 files changed, 44 insertions(+), 60 deletions(-)