From bcd375f7f71f7106c97516bf5395149954ef8810 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Manuel=20Sch=C3=B6lling?= Date: Fri, 13 Jan 2017 21:07:56 +0100 Subject: [PATCH] console: Add callback to flush scrollback buffer to consw struct MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This new callback is in preparation for persistent scrollback buffer support for VGA consoles. With a single scrollback buffer for all consoles, we could flush the buffer just by invocating consw->con_switch(). But when each VGA console has its own scrollback buffer, we need a new callback to tell the video console driver which buffer to flush. Signed-off-by: Manuel Schölling Reviewed-by: Andrey Utkin Tested-by: Andrey Utkin Tested-by: Adam Borowski Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vt.c | 9 +++++++++ drivers/video/console/vgacon.c | 24 +++++++++++++++++++++++- include/linux/console.h | 4 ++++ 3 files changed, 36 insertions(+), 1 deletion(-) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 4c10a9df3b91..9d3ce505e7ab 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -625,6 +625,14 @@ static void save_screen(struct vc_data *vc) vc->vc_sw->con_save_screen(vc); } +static void flush_scrollback(struct vc_data *vc) +{ + WARN_CONSOLE_UNLOCKED(); + + if (vc->vc_sw->con_flush_scrollback) + vc->vc_sw->con_flush_scrollback(vc); +} + /* * Redrawing of screen */ @@ -1171,6 +1179,7 @@ static void csi_J(struct vc_data *vc, int vpar) case 3: /* erase scroll-back buffer (and whole display) */ scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char, vc->vc_screenbuf_size); + flush_scrollback(vc); set_origin(vc); if (con_is_visible(vc)) update_screen(vc); diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index 48b97648d4af..9a7c2bbc5326 100644 --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -173,6 +173,16 @@ static struct vgacon_scrollback_info { int restore; } vgacon_scrollback; +static void vgacon_scrollback_reset(size_t reset_size) +{ + if (vgacon_scrollback.data && reset_size > 0) + memset(vgacon_scrollback.data, 0, reset_size); + + vgacon_scrollback.cnt = 0; + vgacon_scrollback.tail = 0; + vgacon_scrollback.cur = 0; +} + static void vgacon_scrollback_init(int pitch) { int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch; @@ -305,6 +315,14 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines) } else vgacon_cursor(c, CM_MOVE); } + +static void vgacon_flush_scrollback(struct vc_data *c) +{ + size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024; + + if (c->vc_num == fg_console) + vgacon_scrollback_reset(size); +} #else #define vgacon_scrollback_startup(...) do { } while (0) #define vgacon_scrollback_init(...) do { } while (0) @@ -322,6 +340,10 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines) vga_vram_size); vga_set_mem_top(c); } + +static void vgacon_flush_scrollback(struct vc_data *c) +{ +} #endif /* CONFIG_VGACON_SOFT_SCROLLBACK */ static const char *vgacon_startup(void) @@ -1329,7 +1351,6 @@ static bool vgacon_scroll(struct vc_data *c, unsigned int t, unsigned int b, return true; } - /* * The console `switch' structure for the VGA based console */ @@ -1362,6 +1383,7 @@ const struct consw vga_con = { .con_save_screen = vgacon_save_screen, .con_build_attr = vgacon_build_attr, .con_invert_region = vgacon_invert_region, + .con_flush_scrollback = vgacon_flush_scrollback, }; EXPORT_SYMBOL(vga_con); diff --git a/include/linux/console.h b/include/linux/console.h index 9c26c6685587..5949d1855589 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -72,6 +72,10 @@ struct consw { void (*con_invert_region)(struct vc_data *, u16 *, int); u16 *(*con_screen_pos)(struct vc_data *, int); unsigned long (*con_getxy)(struct vc_data *, unsigned long, int *, int *); + /* + * Flush the video console driver's scrollback buffer + */ + void (*con_flush_scrollback)(struct vc_data *); /* * Prepare the console for the debugger. This includes, but is not * limited to, unblanking the console, loading an appropriate -- 2.20.1