| Message ID | 20170105113320.18166-4-manuel.schoelling@gmx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, The patchset generally looks fine to me but I have a question regarding new VGACON_SOFT_SCROLLBACK_PERSISTENT config option. Since the code size impact to support the persistent scrollback feature is minimal wouldn't it be better to always include it? The feature would be disabled by default and could be enabled by using the new kernel command line parameter (you may also add a new config option for enabling it by default if desired). Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics On Thursday, January 05, 2017 12:33:20 PM Manuel Schölling wrote: > 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 <manuel.schoelling@gmx.de> > Reviewed-by: Andrey Utkin <andrey_utkin@fastmail.com> > Tested-by: Andrey Utkin <andrey_utkin@fastmail.com> > Tested-by: Adam Borowski <kilobyte@angband.pl> > --- > 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 c3f1fb9ee820..f500e58f7636 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 9a7c2bbc5326..ca23d222e029 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 */ > } -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tuesday, January 10, 2017 05:22:22 PM Bartlomiej Zolnierkiewicz wrote: > > Hi, > > The patchset generally looks fine to me but I have a question > regarding new VGACON_SOFT_SCROLLBACK_PERSISTENT config option. > > Since the code size impact to support the persistent scrollback > feature is minimal wouldn't it be better to always include it? > > The feature would be disabled by default and could be enabled > by using the new kernel command line parameter (you may also add > a new config option for enabling it by default if desired). Something like: #ifdef VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT static bool scrollback_persistent = 1; #else static bool scrollback_persistent; #endif module_param_named(scrollback_persistent, scrollback_persistent, bool, 0); MODULE_PARM_DESC(scrollback_persistent, "Enable persistent scrollback feature"); and then use scrollback_persistent variable in vgacon_scrollback_switch() to control the actual behavior instead of ifdefs. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics > Best regards, > -- > Bartlomiej Zolnierkiewicz > Samsung R&D Institute Poland > Samsung Electronics > > On Thursday, January 05, 2017 12:33:20 PM Manuel Schölling wrote: > > 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 <manuel.schoelling@gmx.de> > > Reviewed-by: Andrey Utkin <andrey_utkin@fastmail.com> > > Tested-by: Andrey Utkin <andrey_utkin@fastmail.com> > > Tested-by: Adam Borowski <kilobyte@angband.pl> > > --- > > 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 c3f1fb9ee820..f500e58f7636 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 9a7c2bbc5326..ca23d222e029 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 */ > > } -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Bartlomiej, First of all thank you for you feedback! On Tue, 2017-01-10 at 17:44 +0100, Bartlomiej Zolnierkiewicz wrote: > On Tuesday, January 10, 2017 05:22:22 PM Bartlomiej Zolnierkiewicz > wrote: > > > > Hi, > > > > The patchset generally looks fine to me but I have a question > > regarding new VGACON_SOFT_SCROLLBACK_PERSISTENT config option. > > > > Since the code size impact to support the persistent scrollback > > feature is minimal wouldn't it be better to always include it? > > > > The feature would be disabled by default and could be enabled > > by using the new kernel command line parameter (you may also add > > a new config option for enabling it by default if desired). > > Something like: > > #ifdef VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT > static bool scrollback_persistent = 1; > #else > static bool scrollback_persistent; > #endif > > module_param_named(scrollback_persistent, scrollback_persistent, > bool, 0); > MODULE_PARM_DESC(scrollback_persistent, "Enable persistent scrollback > feature"); > > and then use scrollback_persistent variable in > vgacon_scrollback_switch() > to control the actual behavior instead of ifdefs. Sounds pretty good to me. You are right: The code size impact is rather small. I will apply your suggestions and send you another patch as soon as I find the time to implement it (should be any time this week). Thanks again! Manuel > Best regards, > -- > Bartlomiej Zolnierkiewicz > Samsung R&D Institute Poland > Samsung Electronics > > > Best regards, > > -- > > Bartlomiej Zolnierkiewicz > > Samsung R&D Institute Poland > > Samsung Electronics > > > > On Thursday, January 05, 2017 12:33:20 PM Manuel Schölling wrote: > > > 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 <manuel.schoelling@gmx.de> > > > Reviewed-by: Andrey Utkin <andrey_utkin@fastmail.com> > > > Tested-by: Andrey Utkin <andrey_utkin@fastmail.com> > > > Tested-by: Adam Borowski <kilobyte@angband.pl> > > > --- > > > 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 c3f1fb9ee820..f500e58f7636 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 9a7c2bbc5326..ca23d222e029 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 */ > > > } > > -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Changes in v9:
- Make persistent scrollback feature a boot parameter
Changes in v8:
- Add Reviewed-by/Tested-By statements
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 (kilobyte@angband.pl).
- 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(-)
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig index c3f1fb9ee820..f500e58f7636 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 9a7c2bbc5326..ca23d222e029 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 */ }