2016-12-04 10:54:35

by Manuel Schölling

[permalink] [raw]
Subject: [PATCH v7 0/3] console: Add persistent scrollback buffers for all VGA consoles

Reviewed-by: Andrey Utkin <[email protected]>
Tested-by: Andrey Utkin <[email protected]>
Tested-by: Adam Borowski <[email protected]>

--
Changes in v7:
- Add new callback to consw struct for flushing video console driver's
scrollback buffer. Fixes issues with escape sequence '\e[3J' reported
by Adam Borowski ([email protected]).
- Fix style issues
Changes in v6:
- Change of check if feature is enabled in
vgacon_scrollback_switch()
Changes in v5:
- Clearify documentation
- Skip superfluous array initialization
- Disable scrollback if buffer allocation fails
- Refactor vgacon_switch_scrollback()
- Rename vgacon_switch_scrollback() to vgacon_scrollback_switch()
- Add check for fg_console in vgacon_scrollback_update
Changes in v4.1:
- Fix compiler error
Changes in v4:
- Rename from VGACON_SOFT_SCROLLBACK_FOR_EACH_CONSOLE to
VGACON_SOFT_SCROLLBACK_PERSISTENT
- Split into two patches
- Rework documentation
- Remove cosmetic changes in comments (postponed)
Changes in v3:
- Add config option for this feature
- Fallback to old scrollback buffer if kcalloc() fails
- Remove ioctl() call again and add documentation about existing
escape sequence to flush the scrollback buffer
Changes in v2:
- Add ioctl() call to flush scrollback buffer
- (Patch v2 was not labeled as such, sorry)

Manuel Schölling (3):
console: Move scrollback data into its own struct
console: Add callback to flush scrollback buffer to consw struct
console: Add persistent scrollback buffers for all VGA consoles

drivers/tty/vt/vt.c | 9 +++
drivers/video/console/Kconfig | 25 ++++++-
drivers/video/console/vgacon.c | 165 ++++++++++++++++++++++++++++-------------
include/linux/console.h | 4 +
4 files changed, 148 insertions(+), 55 deletions(-)

--
2.1.4


2016-12-04 10:54:36

by Manuel Schölling

[permalink] [raw]
Subject: [PATCH v7 2/3] console: Add callback to flush scrollback buffer to consw struct

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 <[email protected]>
Reviewed-by: Andrey Utkin <[email protected]>
Tested-by: Andrey Utkin <[email protected]>
Tested-by: Adam Borowski <[email protected]>

---
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 4c10a9d..9d3ce50 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 48b9764..9a7c2bb 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 9c26c66..5949d18 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -73,6 +73,10 @@ struct consw {
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
* palette, and allowing debugger generated output.
--
2.1.4

2016-12-04 10:54:58

by Manuel Schölling

[permalink] [raw]
Subject: [PATCH v7 1/3] console: Move scrollback data into its own struct

This refactoring is in preparation for persistent scrollback
support for VGA console.

Signed-off-by: Manuel Schölling <[email protected]>
Reviewed-by: Andrey Utkin <[email protected]>
Tested-by: Andrey Utkin <[email protected]>
Tested-by: Adam Borowski <[email protected]>

---
drivers/video/console/vgacon.c | 91 ++++++++++++++++++++++--------------------
1 file changed, 47 insertions(+), 44 deletions(-)

diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index c22a562..48b9764 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -162,31 +162,34 @@ static inline void vga_set_mem_top(struct vc_data *c)

#ifdef CONFIG_VGACON_SOFT_SCROLLBACK
/* software scrollback */
-static void *vgacon_scrollback;
-static int vgacon_scrollback_tail;
-static int vgacon_scrollback_size;
-static int vgacon_scrollback_rows;
-static int vgacon_scrollback_cnt;
-static int vgacon_scrollback_cur;
-static int vgacon_scrollback_save;
-static int vgacon_scrollback_restore;
+static struct vgacon_scrollback_info {
+ void *data;
+ int tail;
+ int size;
+ int rows;
+ int cnt;
+ int cur;
+ int save;
+ int restore;
+} vgacon_scrollback;

static void vgacon_scrollback_init(int pitch)
{
int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch;

- if (vgacon_scrollback) {
- vgacon_scrollback_cnt = 0;
- vgacon_scrollback_tail = 0;
- vgacon_scrollback_cur = 0;
- vgacon_scrollback_rows = rows - 1;
- vgacon_scrollback_size = rows * pitch;
+ if (vgacon_scrollback.data) {
+ vgacon_scrollback.cnt = 0;
+ vgacon_scrollback.tail = 0;
+ vgacon_scrollback.cur = 0;
+ vgacon_scrollback.rows = rows - 1;
+ vgacon_scrollback.size = rows * pitch;
}
}

static void vgacon_scrollback_startup(void)
{
- vgacon_scrollback = kcalloc(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, 1024, GFP_NOWAIT);
+ vgacon_scrollback.data = kcalloc(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE,
+ 1024, GFP_NOWAIT);
vgacon_scrollback_init(vga_video_num_columns * 2);
}

@@ -194,38 +197,38 @@ static void vgacon_scrollback_update(struct vc_data *c, int t, int count)
{
void *p;

- if (!vgacon_scrollback_size || c->vc_num != fg_console)
+ if (!vgacon_scrollback.size || c->vc_num != fg_console)
return;

p = (void *) (c->vc_origin + t * c->vc_size_row);

while (count--) {
- scr_memcpyw(vgacon_scrollback + vgacon_scrollback_tail,
+ scr_memcpyw(vgacon_scrollback.data + vgacon_scrollback.tail,
p, c->vc_size_row);
- vgacon_scrollback_cnt++;
+ vgacon_scrollback.cnt++;
p += c->vc_size_row;
- vgacon_scrollback_tail += c->vc_size_row;
+ vgacon_scrollback.tail += c->vc_size_row;

- if (vgacon_scrollback_tail >= vgacon_scrollback_size)
- vgacon_scrollback_tail = 0;
+ if (vgacon_scrollback.tail >= vgacon_scrollback.size)
+ vgacon_scrollback.tail = 0;

- if (vgacon_scrollback_cnt > vgacon_scrollback_rows)
- vgacon_scrollback_cnt = vgacon_scrollback_rows;
+ if (vgacon_scrollback.cnt > vgacon_scrollback.rows)
+ vgacon_scrollback.cnt = vgacon_scrollback.rows;

- vgacon_scrollback_cur = vgacon_scrollback_cnt;
+ vgacon_scrollback.cur = vgacon_scrollback.cnt;
}
}

static void vgacon_restore_screen(struct vc_data *c)
{
- vgacon_scrollback_save = 0;
+ vgacon_scrollback.save = 0;

- if (!vga_is_gfx && !vgacon_scrollback_restore) {
+ if (!vga_is_gfx && !vgacon_scrollback.restore) {
scr_memcpyw((u16 *) c->vc_origin, (u16 *) c->vc_screenbuf,
c->vc_screenbuf_size > vga_vram_size ?
vga_vram_size : c->vc_screenbuf_size);
- vgacon_scrollback_restore = 1;
- vgacon_scrollback_cur = vgacon_scrollback_cnt;
+ vgacon_scrollback.restore = 1;
+ vgacon_scrollback.cur = vgacon_scrollback.cnt;
}
}

@@ -239,41 +242,41 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)
return;
}

- if (!vgacon_scrollback)
+ if (!vgacon_scrollback.data)
return;

- if (!vgacon_scrollback_save) {
+ if (!vgacon_scrollback.save) {
vgacon_cursor(c, CM_ERASE);
vgacon_save_screen(c);
- vgacon_scrollback_save = 1;
+ vgacon_scrollback.save = 1;
}

- vgacon_scrollback_restore = 0;
- start = vgacon_scrollback_cur + lines;
+ vgacon_scrollback.restore = 0;
+ start = vgacon_scrollback.cur + lines;
end = start + abs(lines);

if (start < 0)
start = 0;

- if (start > vgacon_scrollback_cnt)
- start = vgacon_scrollback_cnt;
+ if (start > vgacon_scrollback.cnt)
+ start = vgacon_scrollback.cnt;

if (end < 0)
end = 0;

- if (end > vgacon_scrollback_cnt)
- end = vgacon_scrollback_cnt;
+ if (end > vgacon_scrollback.cnt)
+ end = vgacon_scrollback.cnt;

- vgacon_scrollback_cur = start;
+ vgacon_scrollback.cur = start;
count = end - start;
- soff = vgacon_scrollback_tail - ((vgacon_scrollback_cnt - end) *
+ soff = vgacon_scrollback.tail - ((vgacon_scrollback.cnt - end) *
c->vc_size_row);
soff -= count * c->vc_size_row;

if (soff < 0)
- soff += vgacon_scrollback_size;
+ soff += vgacon_scrollback.size;

- count = vgacon_scrollback_cnt - start;
+ count = vgacon_scrollback.cnt - start;

if (count > c->vc_rows)
count = c->vc_rows;
@@ -287,13 +290,13 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)

count *= c->vc_size_row;
/* how much memory to end of buffer left? */
- copysize = min(count, vgacon_scrollback_size - soff);
- scr_memcpyw(d, vgacon_scrollback + soff, copysize);
+ copysize = min(count, vgacon_scrollback.size - soff);
+ scr_memcpyw(d, vgacon_scrollback.data + soff, copysize);
d += copysize;
count -= copysize;

if (count) {
- scr_memcpyw(d, vgacon_scrollback, count);
+ scr_memcpyw(d, vgacon_scrollback.data, count);
d += count;
}

--
2.1.4

2016-12-04 10:55:02

by Manuel Schölling

[permalink] [raw]
Subject: [PATCH v7 3/3] console: Add persistent scrollback buffers for all VGA consoles

Add a scrollback buffers for each VGA console. The benefit is that
the scrollback history is not flushed when switching between consoles
but is persistent.
The buffers are allocated on demand when a new console is opened.

This breaks tools like clear_console that rely on flushing the
scrollback history by switching back and forth between consoles
which is why this feature is disabled by default.
Use the escape sequence \e[3J instead for flushing the buffer.

Signed-off-by: Manuel Schölling <[email protected]>
Reviewed-by: Andrey Utkin <[email protected]>
Tested-by: Andrey Utkin <[email protected]>
Tested-by: Adam Borowski <[email protected]>

---
drivers/video/console/Kconfig | 25 +++++++-
drivers/video/console/vgacon.c | 142 ++++++++++++++++++++++++++---------------
2 files changed, 111 insertions(+), 56 deletions(-)

diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index 38da6e2..c5742d2 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -43,9 +43,28 @@ config VGACON_SOFT_SCROLLBACK_SIZE
range 1 1024
default "64"
help
- Enter the amount of System RAM to allocate for the scrollback
- buffer. Each 64KB will give you approximately 16 80x25
- screenfuls of scrollback buffer
+ Enter the amount of System RAM to allocate for scrollback
+ buffers of VGA consoles. Each 64KB will give you approximately
+ 16 80x25 screenfuls of scrollback buffer.
+
+config VGACON_SOFT_SCROLLBACK_PERSISTENT
+ bool "Persistent Scrollback History for each console"
+ depends on VGACON_SOFT_SCROLLBACK
+ default n
+ help
+ Say Y here if the scrollback history should persist when switching
+ between consoles. Otherwise, the scrollback history will be flushed
+ each time the console is switched.
+
+ This feature might break your tool of choice to flush the scrollback
+ buffer, e.g. clear(1) will work fine but Debian's clear_console(1)
+ will be broken, which might cause security issues.
+ You can use the escape sequence \e[3J instead if this feature is
+ activated.
+
+ Note that a buffer of VGACON_SOFT_SCROLLBACK_SIZE is taken for each
+ created tty device.
+ So if you use a RAM-constrained system, say N here.

config MDA_CONSOLE
depends on !M68K && !PARISC && ISA
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 9a7c2bb..ca23d22 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -162,7 +162,7 @@ static inline void vga_set_mem_top(struct vc_data *c)

#ifdef CONFIG_VGACON_SOFT_SCROLLBACK
/* software scrollback */
-static struct vgacon_scrollback_info {
+struct vgacon_scrollback_info {
void *data;
int tail;
int size;
@@ -171,74 +171,110 @@ static struct vgacon_scrollback_info {
int cur;
int save;
int restore;
-} vgacon_scrollback;
+};
+
+static struct vgacon_scrollback_info *vgacon_scrollback_cur;
+#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
+static struct vgacon_scrollback_info vgacon_scrollbacks[MAX_NR_CONSOLES];
+#else
+static struct vgacon_scrollback_info vgacon_scrollbacks[1];
+#endif

-static void vgacon_scrollback_reset(size_t reset_size)
+static void vgacon_scrollback_reset(int vc_num, size_t reset_size)
{
- if (vgacon_scrollback.data && reset_size > 0)
- memset(vgacon_scrollback.data, 0, reset_size);
+ struct vgacon_scrollback_info *scrollback = &vgacon_scrollbacks[vc_num];
+
+ if (scrollback->data && reset_size > 0)
+ memset(scrollback->data, 0, reset_size);

- vgacon_scrollback.cnt = 0;
- vgacon_scrollback.tail = 0;
- vgacon_scrollback.cur = 0;
+ scrollback->cnt = 0;
+ scrollback->tail = 0;
+ scrollback->cur = 0;
}

-static void vgacon_scrollback_init(int pitch)
+static void vgacon_scrollback_init(int vc_num)
{
- int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch;
-
- if (vgacon_scrollback.data) {
- vgacon_scrollback.cnt = 0;
- vgacon_scrollback.tail = 0;
- vgacon_scrollback.cur = 0;
- vgacon_scrollback.rows = rows - 1;
- vgacon_scrollback.size = rows * pitch;
+ int pitch = vga_video_num_columns * 2;
+ size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;
+ int rows = size / pitch;
+ void *data;
+
+ data = kmalloc_array(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, 1024,
+ GFP_NOWAIT);
+
+ vgacon_scrollbacks[vc_num].data = data;
+ vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num];
+
+ vgacon_scrollback_cur->rows = rows - 1;
+ vgacon_scrollback_cur->size = rows * pitch;
+
+ vgacon_scrollback_reset(vc_num, size);
+}
+
+static void vgacon_scrollback_switch(int vc_num)
+{
+#ifndef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
+ vc_num = 0;
+#endif
+
+ if (!vgacon_scrollbacks[vc_num].data) {
+ vgacon_scrollback_init(vc_num);
+ } else {
+#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
+ vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num];
+#else
+ size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;
+
+ vgacon_scrollback_reset(vc_num, size);
+#endif
}
}

static void vgacon_scrollback_startup(void)
{
- vgacon_scrollback.data = kcalloc(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE,
- 1024, GFP_NOWAIT);
- vgacon_scrollback_init(vga_video_num_columns * 2);
+ vgacon_scrollback_cur = &vgacon_scrollbacks[0];
+ vgacon_scrollback_init(0);
}

static void vgacon_scrollback_update(struct vc_data *c, int t, int count)
{
void *p;

- if (!vgacon_scrollback.size || c->vc_num != fg_console)
+ if (!vgacon_scrollback_cur->data || !vgacon_scrollback_cur->size ||
+ c->vc_num != fg_console)
return;

p = (void *) (c->vc_origin + t * c->vc_size_row);

while (count--) {
- scr_memcpyw(vgacon_scrollback.data + vgacon_scrollback.tail,
+ scr_memcpyw(vgacon_scrollback_cur->data +
+ vgacon_scrollback_cur->tail,
p, c->vc_size_row);
- vgacon_scrollback.cnt++;
+
+ vgacon_scrollback_cur->cnt++;
p += c->vc_size_row;
- vgacon_scrollback.tail += c->vc_size_row;
+ vgacon_scrollback_cur->tail += c->vc_size_row;

- if (vgacon_scrollback.tail >= vgacon_scrollback.size)
- vgacon_scrollback.tail = 0;
+ if (vgacon_scrollback_cur->tail >= vgacon_scrollback_cur->size)
+ vgacon_scrollback_cur->tail = 0;

- if (vgacon_scrollback.cnt > vgacon_scrollback.rows)
- vgacon_scrollback.cnt = vgacon_scrollback.rows;
+ if (vgacon_scrollback_cur->cnt > vgacon_scrollback_cur->rows)
+ vgacon_scrollback_cur->cnt = vgacon_scrollback_cur->rows;

- vgacon_scrollback.cur = vgacon_scrollback.cnt;
+ vgacon_scrollback_cur->cur = vgacon_scrollback_cur->cnt;
}
}

static void vgacon_restore_screen(struct vc_data *c)
{
- vgacon_scrollback.save = 0;
+ vgacon_scrollback_cur->save = 0;

- if (!vga_is_gfx && !vgacon_scrollback.restore) {
+ if (!vga_is_gfx && !vgacon_scrollback_cur->restore) {
scr_memcpyw((u16 *) c->vc_origin, (u16 *) c->vc_screenbuf,
c->vc_screenbuf_size > vga_vram_size ?
vga_vram_size : c->vc_screenbuf_size);
- vgacon_scrollback.restore = 1;
- vgacon_scrollback.cur = vgacon_scrollback.cnt;
+ vgacon_scrollback_cur->restore = 1;
+ vgacon_scrollback_cur->cur = vgacon_scrollback_cur->cnt;
}
}

@@ -252,41 +288,41 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)
return;
}

- if (!vgacon_scrollback.data)
+ if (!vgacon_scrollback_cur->data)
return;

- if (!vgacon_scrollback.save) {
+ if (!vgacon_scrollback_cur->save) {
vgacon_cursor(c, CM_ERASE);
vgacon_save_screen(c);
- vgacon_scrollback.save = 1;
+ vgacon_scrollback_cur->save = 1;
}

- vgacon_scrollback.restore = 0;
- start = vgacon_scrollback.cur + lines;
+ vgacon_scrollback_cur->restore = 0;
+ start = vgacon_scrollback_cur->cur + lines;
end = start + abs(lines);

if (start < 0)
start = 0;

- if (start > vgacon_scrollback.cnt)
- start = vgacon_scrollback.cnt;
+ if (start > vgacon_scrollback_cur->cnt)
+ start = vgacon_scrollback_cur->cnt;

if (end < 0)
end = 0;

- if (end > vgacon_scrollback.cnt)
- end = vgacon_scrollback.cnt;
+ if (end > vgacon_scrollback_cur->cnt)
+ end = vgacon_scrollback_cur->cnt;

- vgacon_scrollback.cur = start;
+ vgacon_scrollback_cur->cur = start;
count = end - start;
- soff = vgacon_scrollback.tail - ((vgacon_scrollback.cnt - end) *
- c->vc_size_row);
+ soff = vgacon_scrollback_cur->tail -
+ ((vgacon_scrollback_cur->cnt - end) * c->vc_size_row);
soff -= count * c->vc_size_row;

if (soff < 0)
- soff += vgacon_scrollback.size;
+ soff += vgacon_scrollback_cur->size;

- count = vgacon_scrollback.cnt - start;
+ count = vgacon_scrollback_cur->cnt - start;

if (count > c->vc_rows)
count = c->vc_rows;
@@ -300,13 +336,13 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)

count *= c->vc_size_row;
/* how much memory to end of buffer left? */
- copysize = min(count, vgacon_scrollback.size - soff);
- scr_memcpyw(d, vgacon_scrollback.data + soff, copysize);
+ copysize = min(count, vgacon_scrollback_cur->size - soff);
+ scr_memcpyw(d, vgacon_scrollback_cur->data + soff, copysize);
d += copysize;
count -= copysize;

if (count) {
- scr_memcpyw(d, vgacon_scrollback.data, count);
+ scr_memcpyw(d, vgacon_scrollback_cur->data, count);
d += count;
}

@@ -320,13 +356,13 @@ 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);
+ vgacon_scrollback_reset(c->vc_num, size);
}
#else
#define vgacon_scrollback_startup(...) do { } while (0)
#define vgacon_scrollback_init(...) do { } while (0)
#define vgacon_scrollback_update(...) do { } while (0)
+#define vgacon_scrollback_switch(...) do { } while (0)

static void vgacon_restore_screen(struct vc_data *c)
{
@@ -805,7 +841,7 @@ static int vgacon_switch(struct vc_data *c)
vgacon_doresize(c, c->vc_cols, c->vc_rows);
}

- vgacon_scrollback_init(c->vc_size_row);
+ vgacon_scrollback_switch(c->vc_num);
return 0; /* Redrawing not needed */
}

--
2.1.4

2016-12-06 10:02:38

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH v7 0/3] console: Add persistent scrollback buffers for all VGA consoles

On Sun, Dec 04, 2016 at 11:53:53AM +0100, Manuel Sch?lling wrote:
> Reviewed-by: Andrey Utkin <[email protected]>
> Tested-by: Andrey Utkin <[email protected]>
> Tested-by: Adam Borowski <[email protected]>
>
> --
> Changes in v7:
> - Add new callback to consw struct for flushing video console driver's
> scrollback buffer. Fixes issues with escape sequence '\e[3J' reported
> by Adam Borowski ([email protected]).
> - Fix style issues

But this is now v8, right? I see two v7 patch series in my inbox :(

confused,

greg k-h

2016-12-06 16:41:51

by Manuel Schölling

[permalink] [raw]
Subject: Re: [PATCH v7 0/3] console: Add persistent scrollback buffers for all VGA consoles

Hi Greg,

On Di, 2016-12-06 at 11:02 +0100, Greg KH wrote:
> On Sun, Dec 04, 2016 at 11:53:53AM +0100, Manuel Schölling wrote:
> > Reviewed-by: Andrey Utkin <[email protected]>
> > Tested-by: Andrey Utkin <[email protected]>
> > Tested-by: Adam Borowski <[email protected]>
> >
> > --
> > Changes in v7:
> > - Add new callback to consw struct for flushing video console driver's
> > scrollback buffer. Fixes issues with escape sequence '\e[3J' reported
> > by Adam Borowski ([email protected]).
> > - Fix style issues
>
> But this is now v8, right? I see two v7 patch series in my inbox :(
>
> confused,
Sorry for causing confusion. I wasn't sure about the workflow so asked
on #kernelnewbies a few days ago but apparently I misunderstood the
advice I got there:

This is just the same patch (v7) as I sent before, but I added the
Tested-By/Reviewed-By tags.


2016-12-21 16:38:20

by Manuel Schölling

[permalink] [raw]
Subject: [PATCH RESEND v7 0/3] console: Add persistent scrollback buffers for all VGA consoles

Reviewed-by: Andrey Utkin <[email protected]>
Tested-by: Andrey Utkin <[email protected]>
Tested-by: Adam Borowski <[email protected]>

--
Changes in v7:
- Add new callback to consw struct for flushing video console driver's
scrollback buffer. Fixes issues with escape sequence '\e[3J' reported
by Adam Borowski ([email protected]).
- Fix style issues
Changes in v6:
- Change of check if feature is enabled in
vgacon_scrollback_switch()
Changes in v5:
- Clearify documentation
- Skip superfluous array initialization
- Disable scrollback if buffer allocation fails
- Refactor vgacon_switch_scrollback()
- Rename vgacon_switch_scrollback() to vgacon_scrollback_switch()
- Add check for fg_console in vgacon_scrollback_update
Changes in v4.1:
- Fix compiler error
Changes in v4:
- Rename from VGACON_SOFT_SCROLLBACK_FOR_EACH_CONSOLE to
VGACON_SOFT_SCROLLBACK_PERSISTENT
- Split into two patches
- Rework documentation
- Remove cosmetic changes in comments (postponed)
Changes in v3:
- Add config option for this feature
- Fallback to old scrollback buffer if kcalloc() fails
- Remove ioctl() call again and add documentation about existing
escape sequence to flush the scrollback buffer
Changes in v2:
- Add ioctl() call to flush scrollback buffer
- (Patch v2 was not labeled as such, sorry)

Manuel Schölling (3):
console: Move scrollback data into its own struct
console: Add callback to flush scrollback buffer to consw struct
console: Add persistent scrollback buffers for all VGA consoles

drivers/tty/vt/vt.c | 9 +++
drivers/video/console/Kconfig | 25 ++++++-
drivers/video/console/vgacon.c | 165 ++++++++++++++++++++++++++++-------------
include/linux/console.h | 4 +
4 files changed, 148 insertions(+), 55 deletions(-)

--
2.1.4

2016-12-21 16:38:25

by Manuel Schölling

[permalink] [raw]
Subject: [PATCH RESEND v7 3/3] console: Add persistent scrollback buffers for all VGA consoles

Add a scrollback buffers for each VGA console. The benefit is that
the scrollback history is not flushed when switching between consoles
but is persistent.
The buffers are allocated on demand when a new console is opened.

This breaks tools like clear_console that rely on flushing the
scrollback history by switching back and forth between consoles
which is why this feature is disabled by default.
Use the escape sequence \e[3J instead for flushing the buffer.

Signed-off-by: Manuel Schölling <[email protected]>
Reviewed-by: Andrey Utkin <[email protected]>
Tested-by: Andrey Utkin <[email protected]>
Tested-by: Adam Borowski <[email protected]>

---
drivers/video/console/Kconfig | 25 +++++++-
drivers/video/console/vgacon.c | 142 ++++++++++++++++++++++++++---------------
2 files changed, 111 insertions(+), 56 deletions(-)

diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index 38da6e2..c5742d2 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -43,9 +43,28 @@ config VGACON_SOFT_SCROLLBACK_SIZE
range 1 1024
default "64"
help
- Enter the amount of System RAM to allocate for the scrollback
- buffer. Each 64KB will give you approximately 16 80x25
- screenfuls of scrollback buffer
+ Enter the amount of System RAM to allocate for scrollback
+ buffers of VGA consoles. Each 64KB will give you approximately
+ 16 80x25 screenfuls of scrollback buffer.
+
+config VGACON_SOFT_SCROLLBACK_PERSISTENT
+ bool "Persistent Scrollback History for each console"
+ depends on VGACON_SOFT_SCROLLBACK
+ default n
+ help
+ Say Y here if the scrollback history should persist when switching
+ between consoles. Otherwise, the scrollback history will be flushed
+ each time the console is switched.
+
+ This feature might break your tool of choice to flush the scrollback
+ buffer, e.g. clear(1) will work fine but Debian's clear_console(1)
+ will be broken, which might cause security issues.
+ You can use the escape sequence \e[3J instead if this feature is
+ activated.
+
+ Note that a buffer of VGACON_SOFT_SCROLLBACK_SIZE is taken for each
+ created tty device.
+ So if you use a RAM-constrained system, say N here.

config MDA_CONSOLE
depends on !M68K && !PARISC && ISA
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 9a7c2bb..ca23d22 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -162,7 +162,7 @@ static inline void vga_set_mem_top(struct vc_data *c)

#ifdef CONFIG_VGACON_SOFT_SCROLLBACK
/* software scrollback */
-static struct vgacon_scrollback_info {
+struct vgacon_scrollback_info {
void *data;
int tail;
int size;
@@ -171,74 +171,110 @@ static struct vgacon_scrollback_info {
int cur;
int save;
int restore;
-} vgacon_scrollback;
+};
+
+static struct vgacon_scrollback_info *vgacon_scrollback_cur;
+#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
+static struct vgacon_scrollback_info vgacon_scrollbacks[MAX_NR_CONSOLES];
+#else
+static struct vgacon_scrollback_info vgacon_scrollbacks[1];
+#endif

-static void vgacon_scrollback_reset(size_t reset_size)
+static void vgacon_scrollback_reset(int vc_num, size_t reset_size)
{
- if (vgacon_scrollback.data && reset_size > 0)
- memset(vgacon_scrollback.data, 0, reset_size);
+ struct vgacon_scrollback_info *scrollback = &vgacon_scrollbacks[vc_num];
+
+ if (scrollback->data && reset_size > 0)
+ memset(scrollback->data, 0, reset_size);

- vgacon_scrollback.cnt = 0;
- vgacon_scrollback.tail = 0;
- vgacon_scrollback.cur = 0;
+ scrollback->cnt = 0;
+ scrollback->tail = 0;
+ scrollback->cur = 0;
}

-static void vgacon_scrollback_init(int pitch)
+static void vgacon_scrollback_init(int vc_num)
{
- int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch;
-
- if (vgacon_scrollback.data) {
- vgacon_scrollback.cnt = 0;
- vgacon_scrollback.tail = 0;
- vgacon_scrollback.cur = 0;
- vgacon_scrollback.rows = rows - 1;
- vgacon_scrollback.size = rows * pitch;
+ int pitch = vga_video_num_columns * 2;
+ size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;
+ int rows = size / pitch;
+ void *data;
+
+ data = kmalloc_array(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, 1024,
+ GFP_NOWAIT);
+
+ vgacon_scrollbacks[vc_num].data = data;
+ vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num];
+
+ vgacon_scrollback_cur->rows = rows - 1;
+ vgacon_scrollback_cur->size = rows * pitch;
+
+ vgacon_scrollback_reset(vc_num, size);
+}
+
+static void vgacon_scrollback_switch(int vc_num)
+{
+#ifndef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
+ vc_num = 0;
+#endif
+
+ if (!vgacon_scrollbacks[vc_num].data) {
+ vgacon_scrollback_init(vc_num);
+ } else {
+#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
+ vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num];
+#else
+ size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;
+
+ vgacon_scrollback_reset(vc_num, size);
+#endif
}
}

static void vgacon_scrollback_startup(void)
{
- vgacon_scrollback.data = kcalloc(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE,
- 1024, GFP_NOWAIT);
- vgacon_scrollback_init(vga_video_num_columns * 2);
+ vgacon_scrollback_cur = &vgacon_scrollbacks[0];
+ vgacon_scrollback_init(0);
}

static void vgacon_scrollback_update(struct vc_data *c, int t, int count)
{
void *p;

- if (!vgacon_scrollback.size || c->vc_num != fg_console)
+ if (!vgacon_scrollback_cur->data || !vgacon_scrollback_cur->size ||
+ c->vc_num != fg_console)
return;

p = (void *) (c->vc_origin + t * c->vc_size_row);

while (count--) {
- scr_memcpyw(vgacon_scrollback.data + vgacon_scrollback.tail,
+ scr_memcpyw(vgacon_scrollback_cur->data +
+ vgacon_scrollback_cur->tail,
p, c->vc_size_row);
- vgacon_scrollback.cnt++;
+
+ vgacon_scrollback_cur->cnt++;
p += c->vc_size_row;
- vgacon_scrollback.tail += c->vc_size_row;
+ vgacon_scrollback_cur->tail += c->vc_size_row;

- if (vgacon_scrollback.tail >= vgacon_scrollback.size)
- vgacon_scrollback.tail = 0;
+ if (vgacon_scrollback_cur->tail >= vgacon_scrollback_cur->size)
+ vgacon_scrollback_cur->tail = 0;

- if (vgacon_scrollback.cnt > vgacon_scrollback.rows)
- vgacon_scrollback.cnt = vgacon_scrollback.rows;
+ if (vgacon_scrollback_cur->cnt > vgacon_scrollback_cur->rows)
+ vgacon_scrollback_cur->cnt = vgacon_scrollback_cur->rows;

- vgacon_scrollback.cur = vgacon_scrollback.cnt;
+ vgacon_scrollback_cur->cur = vgacon_scrollback_cur->cnt;
}
}

static void vgacon_restore_screen(struct vc_data *c)
{
- vgacon_scrollback.save = 0;
+ vgacon_scrollback_cur->save = 0;

- if (!vga_is_gfx && !vgacon_scrollback.restore) {
+ if (!vga_is_gfx && !vgacon_scrollback_cur->restore) {
scr_memcpyw((u16 *) c->vc_origin, (u16 *) c->vc_screenbuf,
c->vc_screenbuf_size > vga_vram_size ?
vga_vram_size : c->vc_screenbuf_size);
- vgacon_scrollback.restore = 1;
- vgacon_scrollback.cur = vgacon_scrollback.cnt;
+ vgacon_scrollback_cur->restore = 1;
+ vgacon_scrollback_cur->cur = vgacon_scrollback_cur->cnt;
}
}

@@ -252,41 +288,41 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)
return;
}

- if (!vgacon_scrollback.data)
+ if (!vgacon_scrollback_cur->data)
return;

- if (!vgacon_scrollback.save) {
+ if (!vgacon_scrollback_cur->save) {
vgacon_cursor(c, CM_ERASE);
vgacon_save_screen(c);
- vgacon_scrollback.save = 1;
+ vgacon_scrollback_cur->save = 1;
}

- vgacon_scrollback.restore = 0;
- start = vgacon_scrollback.cur + lines;
+ vgacon_scrollback_cur->restore = 0;
+ start = vgacon_scrollback_cur->cur + lines;
end = start + abs(lines);

if (start < 0)
start = 0;

- if (start > vgacon_scrollback.cnt)
- start = vgacon_scrollback.cnt;
+ if (start > vgacon_scrollback_cur->cnt)
+ start = vgacon_scrollback_cur->cnt;

if (end < 0)
end = 0;

- if (end > vgacon_scrollback.cnt)
- end = vgacon_scrollback.cnt;
+ if (end > vgacon_scrollback_cur->cnt)
+ end = vgacon_scrollback_cur->cnt;

- vgacon_scrollback.cur = start;
+ vgacon_scrollback_cur->cur = start;
count = end - start;
- soff = vgacon_scrollback.tail - ((vgacon_scrollback.cnt - end) *
- c->vc_size_row);
+ soff = vgacon_scrollback_cur->tail -
+ ((vgacon_scrollback_cur->cnt - end) * c->vc_size_row);
soff -= count * c->vc_size_row;

if (soff < 0)
- soff += vgacon_scrollback.size;
+ soff += vgacon_scrollback_cur->size;

- count = vgacon_scrollback.cnt - start;
+ count = vgacon_scrollback_cur->cnt - start;

if (count > c->vc_rows)
count = c->vc_rows;
@@ -300,13 +336,13 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)

count *= c->vc_size_row;
/* how much memory to end of buffer left? */
- copysize = min(count, vgacon_scrollback.size - soff);
- scr_memcpyw(d, vgacon_scrollback.data + soff, copysize);
+ copysize = min(count, vgacon_scrollback_cur->size - soff);
+ scr_memcpyw(d, vgacon_scrollback_cur->data + soff, copysize);
d += copysize;
count -= copysize;

if (count) {
- scr_memcpyw(d, vgacon_scrollback.data, count);
+ scr_memcpyw(d, vgacon_scrollback_cur->data, count);
d += count;
}

@@ -320,13 +356,13 @@ 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);
+ vgacon_scrollback_reset(c->vc_num, size);
}
#else
#define vgacon_scrollback_startup(...) do { } while (0)
#define vgacon_scrollback_init(...) do { } while (0)
#define vgacon_scrollback_update(...) do { } while (0)
+#define vgacon_scrollback_switch(...) do { } while (0)

static void vgacon_restore_screen(struct vc_data *c)
{
@@ -805,7 +841,7 @@ static int vgacon_switch(struct vc_data *c)
vgacon_doresize(c, c->vc_cols, c->vc_rows);
}

- vgacon_scrollback_init(c->vc_size_row);
+ vgacon_scrollback_switch(c->vc_num);
return 0; /* Redrawing not needed */
}

--
2.1.4

2016-12-21 16:38:56

by Manuel Schölling

[permalink] [raw]
Subject: [PATCH RESEND v7 2/3] console: Add callback to flush scrollback buffer to consw struct

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 <[email protected]>
Reviewed-by: Andrey Utkin <[email protected]>
Tested-by: Andrey Utkin <[email protected]>
Tested-by: Adam Borowski <[email protected]>

---
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 4c10a9d..9d3ce50 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 48b9764..9a7c2bb 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 9c26c66..5949d18 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -73,6 +73,10 @@ struct consw {
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
* palette, and allowing debugger generated output.
--
2.1.4

2016-12-21 16:38:23

by Manuel Schölling

[permalink] [raw]
Subject: [PATCH RESEND v7 1/3] console: Move scrollback data into its own struct

This refactoring is in preparation for persistent scrollback
support for VGA console.

Signed-off-by: Manuel Schölling <[email protected]>
Reviewed-by: Andrey Utkin <[email protected]>
Tested-by: Andrey Utkin <[email protected]>
Tested-by: Adam Borowski <[email protected]>

---
drivers/video/console/vgacon.c | 91 ++++++++++++++++++++++--------------------
1 file changed, 47 insertions(+), 44 deletions(-)

diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index c22a562..48b9764 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -162,31 +162,34 @@ static inline void vga_set_mem_top(struct vc_data *c)

#ifdef CONFIG_VGACON_SOFT_SCROLLBACK
/* software scrollback */
-static void *vgacon_scrollback;
-static int vgacon_scrollback_tail;
-static int vgacon_scrollback_size;
-static int vgacon_scrollback_rows;
-static int vgacon_scrollback_cnt;
-static int vgacon_scrollback_cur;
-static int vgacon_scrollback_save;
-static int vgacon_scrollback_restore;
+static struct vgacon_scrollback_info {
+ void *data;
+ int tail;
+ int size;
+ int rows;
+ int cnt;
+ int cur;
+ int save;
+ int restore;
+} vgacon_scrollback;

static void vgacon_scrollback_init(int pitch)
{
int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch;

- if (vgacon_scrollback) {
- vgacon_scrollback_cnt = 0;
- vgacon_scrollback_tail = 0;
- vgacon_scrollback_cur = 0;
- vgacon_scrollback_rows = rows - 1;
- vgacon_scrollback_size = rows * pitch;
+ if (vgacon_scrollback.data) {
+ vgacon_scrollback.cnt = 0;
+ vgacon_scrollback.tail = 0;
+ vgacon_scrollback.cur = 0;
+ vgacon_scrollback.rows = rows - 1;
+ vgacon_scrollback.size = rows * pitch;
}
}

static void vgacon_scrollback_startup(void)
{
- vgacon_scrollback = kcalloc(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, 1024, GFP_NOWAIT);
+ vgacon_scrollback.data = kcalloc(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE,
+ 1024, GFP_NOWAIT);
vgacon_scrollback_init(vga_video_num_columns * 2);
}

@@ -194,38 +197,38 @@ static void vgacon_scrollback_update(struct vc_data *c, int t, int count)
{
void *p;

- if (!vgacon_scrollback_size || c->vc_num != fg_console)
+ if (!vgacon_scrollback.size || c->vc_num != fg_console)
return;

p = (void *) (c->vc_origin + t * c->vc_size_row);

while (count--) {
- scr_memcpyw(vgacon_scrollback + vgacon_scrollback_tail,
+ scr_memcpyw(vgacon_scrollback.data + vgacon_scrollback.tail,
p, c->vc_size_row);
- vgacon_scrollback_cnt++;
+ vgacon_scrollback.cnt++;
p += c->vc_size_row;
- vgacon_scrollback_tail += c->vc_size_row;
+ vgacon_scrollback.tail += c->vc_size_row;

- if (vgacon_scrollback_tail >= vgacon_scrollback_size)
- vgacon_scrollback_tail = 0;
+ if (vgacon_scrollback.tail >= vgacon_scrollback.size)
+ vgacon_scrollback.tail = 0;

- if (vgacon_scrollback_cnt > vgacon_scrollback_rows)
- vgacon_scrollback_cnt = vgacon_scrollback_rows;
+ if (vgacon_scrollback.cnt > vgacon_scrollback.rows)
+ vgacon_scrollback.cnt = vgacon_scrollback.rows;

- vgacon_scrollback_cur = vgacon_scrollback_cnt;
+ vgacon_scrollback.cur = vgacon_scrollback.cnt;
}
}

static void vgacon_restore_screen(struct vc_data *c)
{
- vgacon_scrollback_save = 0;
+ vgacon_scrollback.save = 0;

- if (!vga_is_gfx && !vgacon_scrollback_restore) {
+ if (!vga_is_gfx && !vgacon_scrollback.restore) {
scr_memcpyw((u16 *) c->vc_origin, (u16 *) c->vc_screenbuf,
c->vc_screenbuf_size > vga_vram_size ?
vga_vram_size : c->vc_screenbuf_size);
- vgacon_scrollback_restore = 1;
- vgacon_scrollback_cur = vgacon_scrollback_cnt;
+ vgacon_scrollback.restore = 1;
+ vgacon_scrollback.cur = vgacon_scrollback.cnt;
}
}

@@ -239,41 +242,41 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)
return;
}

- if (!vgacon_scrollback)
+ if (!vgacon_scrollback.data)
return;

- if (!vgacon_scrollback_save) {
+ if (!vgacon_scrollback.save) {
vgacon_cursor(c, CM_ERASE);
vgacon_save_screen(c);
- vgacon_scrollback_save = 1;
+ vgacon_scrollback.save = 1;
}

- vgacon_scrollback_restore = 0;
- start = vgacon_scrollback_cur + lines;
+ vgacon_scrollback.restore = 0;
+ start = vgacon_scrollback.cur + lines;
end = start + abs(lines);

if (start < 0)
start = 0;

- if (start > vgacon_scrollback_cnt)
- start = vgacon_scrollback_cnt;
+ if (start > vgacon_scrollback.cnt)
+ start = vgacon_scrollback.cnt;

if (end < 0)
end = 0;

- if (end > vgacon_scrollback_cnt)
- end = vgacon_scrollback_cnt;
+ if (end > vgacon_scrollback.cnt)
+ end = vgacon_scrollback.cnt;

- vgacon_scrollback_cur = start;
+ vgacon_scrollback.cur = start;
count = end - start;
- soff = vgacon_scrollback_tail - ((vgacon_scrollback_cnt - end) *
+ soff = vgacon_scrollback.tail - ((vgacon_scrollback.cnt - end) *
c->vc_size_row);
soff -= count * c->vc_size_row;

if (soff < 0)
- soff += vgacon_scrollback_size;
+ soff += vgacon_scrollback.size;

- count = vgacon_scrollback_cnt - start;
+ count = vgacon_scrollback.cnt - start;

if (count > c->vc_rows)
count = c->vc_rows;
@@ -287,13 +290,13 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)

count *= c->vc_size_row;
/* how much memory to end of buffer left? */
- copysize = min(count, vgacon_scrollback_size - soff);
- scr_memcpyw(d, vgacon_scrollback + soff, copysize);
+ copysize = min(count, vgacon_scrollback.size - soff);
+ scr_memcpyw(d, vgacon_scrollback.data + soff, copysize);
d += copysize;
count -= copysize;

if (count) {
- scr_memcpyw(d, vgacon_scrollback, count);
+ scr_memcpyw(d, vgacon_scrollback.data, count);
d += count;
}

--
2.1.4