[v2,5/9] vgacon: remove screen_info dependency

Message ID 20230719123944.3438363-6-arnd@kernel.org
State New
Headers
Series video: screen_info cleanups |

Commit Message

Arnd Bergmann July 19, 2023, 12:39 p.m. UTC
  From: Arnd Bergmann <arnd@arndb.de>

The vga console driver is fairly self-contained, and only used by
architectures that explicitly initialize the screen_info settings.

Chance every instance that picks the vga console by setting conswitchp
to call a function instead, and pass a reference to the screen_info
there.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/alpha/kernel/setup.c      |  2 +-
 arch/arm/kernel/setup.c        |  2 +-
 arch/ia64/kernel/setup.c       |  2 +-
 arch/mips/kernel/setup.c       |  2 +-
 arch/x86/kernel/setup.c        |  2 +-
 drivers/firmware/pcdp.c        |  2 +-
 drivers/video/console/vgacon.c | 68 ++++++++++++++++++++--------------
 include/linux/console.h        |  7 ++++
 8 files changed, 53 insertions(+), 34 deletions(-)
  

Comments

Javier Martinez Canillas July 19, 2023, 1:49 p.m. UTC | #1
Arnd Bergmann <arnd@kernel.org> writes:

> From: Arnd Bergmann <arnd@arndb.de>
>
> The vga console driver is fairly self-contained, and only used by
> architectures that explicitly initialize the screen_info settings.
>
> Chance every instance that picks the vga console by setting conswitchp
> to call a function instead, and pass a reference to the screen_info
> there.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
  
Philippe Mathieu-Daudé July 19, 2023, 1:49 p.m. UTC | #2
Hi Arnd,

On 19/7/23 14:39, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The vga console driver is fairly self-contained, and only used by
> architectures that explicitly initialize the screen_info settings.
> 
> Chance every instance that picks the vga console by setting conswitchp
> to call a function instead, and pass a reference to the screen_info
> there.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   arch/alpha/kernel/setup.c      |  2 +-
>   arch/arm/kernel/setup.c        |  2 +-
>   arch/ia64/kernel/setup.c       |  2 +-
>   arch/mips/kernel/setup.c       |  2 +-
>   arch/x86/kernel/setup.c        |  2 +-
>   drivers/firmware/pcdp.c        |  2 +-
>   drivers/video/console/vgacon.c | 68 ++++++++++++++++++++--------------
>   include/linux/console.h        |  7 ++++
>   8 files changed, 53 insertions(+), 34 deletions(-)


> @@ -1074,13 +1077,13 @@ static int vgacon_resize(struct vc_data *c, unsigned int width,
>   		 * Ho ho!  Someone (svgatextmode, eh?) may have reprogrammed
>   		 * the video mode!  Set the new defaults then and go away.
>   		 */
> -		screen_info.orig_video_cols = width;
> -		screen_info.orig_video_lines = height;
> +		vga_si->orig_video_cols = width;
> +		vga_si->orig_video_lines = height;
>   		vga_default_font_height = c->vc_cell_height;
>   		return 0;
>   	}
> -	if (width % 2 || width > screen_info.orig_video_cols ||
> -	    height > (screen_info.orig_video_lines * vga_default_font_height)/
> +	if (width % 2 || width > vga_si->orig_video_cols ||
> +	    height > (vga_si->orig_video_lines * vga_default_font_height)/
>   	    c->vc_cell_height)
>   		return -EINVAL;
>   
> @@ -1110,8 +1113,8 @@ static void vgacon_save_screen(struct vc_data *c)
>   		 * console initialization routines.
>   		 */
>   		vga_bootup_console = 1;
> -		c->state.x = screen_info.orig_x;
> -		c->state.y = screen_info.orig_y;
> +		c->state.x = vga_si->orig_x;
> +		c->state.y = vga_si->orig_y;

Not really my area, so bare with me if this is obviously not
possible :) If using DUMMY_CONSOLE, can we trigger a save_screen
/ resize? If so, we'd reach here with vga_si=NULL.

>   	}
>   
>   	/* We can't copy in more than the size of the video buffer,
> @@ -1204,4 +1207,13 @@ const struct consw vga_con = {
>   };
>   EXPORT_SYMBOL(vga_con);
>   
> +void vgacon_register_screen(struct screen_info *si)
> +{
> +	if (!si || vga_si)
> +		return;
> +
> +	conswitchp = &vga_con;
> +	vga_si = si;
> +}
  
Arnd Bergmann July 19, 2023, 2:38 p.m. UTC | #3
On Wed, Jul 19, 2023, at 15:49, Philippe Mathieu-Daudé wrote:
> On 19/7/23 14:39, Arnd Bergmann wrote:

>> @@ -1074,13 +1077,13 @@ static int vgacon_resize(struct vc_data *c, unsigned int width,
>>   		 * Ho ho!  Someone (svgatextmode, eh?) may have reprogrammed
>>   		 * the video mode!  Set the new defaults then and go away.
>>   		 */
>> -		screen_info.orig_video_cols = width;
>> -		screen_info.orig_video_lines = height;
>> +		vga_si->orig_video_cols = width;
>> +		vga_si->orig_video_lines = height;
>>   		vga_default_font_height = c->vc_cell_height;
>>   		return 0;
>>   	}
>> -	if (width % 2 || width > screen_info.orig_video_cols ||
>> -	    height > (screen_info.orig_video_lines * vga_default_font_height)/
>> +	if (width % 2 || width > vga_si->orig_video_cols ||
>> +	    height > (vga_si->orig_video_lines * vga_default_font_height)/
>>   	    c->vc_cell_height)
>>   		return -EINVAL;
>>   
>> @@ -1110,8 +1113,8 @@ static void vgacon_save_screen(struct vc_data *c)
>>   		 * console initialization routines.
>>   		 */
>>   		vga_bootup_console = 1;
>> -		c->state.x = screen_info.orig_x;
>> -		c->state.y = screen_info.orig_y;
>> +		c->state.x = vga_si->orig_x;
>> +		c->state.y = vga_si->orig_y;
>
> Not really my area, so bare with me if this is obviously not
> possible :) If using DUMMY_CONSOLE, can we trigger a save_screen
> / resize? If so, we'd reach here with vga_si=NULL.
>

I think it cannot happen because the only way that anything calls
into vgacon.c is through the "conswitchp = &vga_con;" that now happens
at the same time as the "vga_si = &screen_info;". It's definitely
possible that I'm missing something as well here.

     Arnd
  
Khalid Aziz July 20, 2023, 6:51 p.m. UTC | #4
On 7/19/23 6:39 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The vga console driver is fairly self-contained, and only used by
> architectures that explicitly initialize the screen_info settings.
> 
> Chance every instance that picks the vga console by setting conswitchp
> to call a function instead, and pass a reference to the screen_info
> there.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

PCDP and ia64 changes look good to me.

Acked-by: Khalid Azzi <khalid@gonehiking.org>

> ---
>   arch/alpha/kernel/setup.c      |  2 +-
>   arch/arm/kernel/setup.c        |  2 +-
>   arch/ia64/kernel/setup.c       |  2 +-
>   arch/mips/kernel/setup.c       |  2 +-
>   arch/x86/kernel/setup.c        |  2 +-
>   drivers/firmware/pcdp.c        |  2 +-
>   drivers/video/console/vgacon.c | 68 ++++++++++++++++++++--------------
>   include/linux/console.h        |  7 ++++
>   8 files changed, 53 insertions(+), 34 deletions(-)
> 
> diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
> index b4d2297765c02..d73b685fe9852 100644
> --- a/arch/alpha/kernel/setup.c
> +++ b/arch/alpha/kernel/setup.c
> @@ -655,7 +655,7 @@ setup_arch(char **cmdline_p)
>   
>   #ifdef CONFIG_VT
>   #if defined(CONFIG_VGA_CONSOLE)
> -	conswitchp = &vga_con;
> +	vgacon_register_screen(&screen_info);
>   #endif
>   #endif
>   
> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> index 40326a35a179b..5d8a7fb3eba45 100644
> --- a/arch/arm/kernel/setup.c
> +++ b/arch/arm/kernel/setup.c
> @@ -1192,7 +1192,7 @@ void __init setup_arch(char **cmdline_p)
>   
>   #ifdef CONFIG_VT
>   #if defined(CONFIG_VGA_CONSOLE)
> -	conswitchp = &vga_con;
> +	vgacon_register_screen(&screen_info);
>   #endif
>   #endif
>   
> diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
> index d2c66efdde560..2c9283fcd3759 100644
> --- a/arch/ia64/kernel/setup.c
> +++ b/arch/ia64/kernel/setup.c
> @@ -619,7 +619,7 @@ setup_arch (char **cmdline_p)
>   		 * memory so we can avoid this problem.
>   		 */
>   		if (efi_mem_type(0xA0000) != EFI_CONVENTIONAL_MEMORY)
> -			conswitchp = &vga_con;
> +			vgacon_register_screen(&screen_info);
>   # endif
>   	}
>   #endif
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 1aba7dc95132c..6c3fae62a9f6b 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -794,7 +794,7 @@ void __init setup_arch(char **cmdline_p)
>   
>   #if defined(CONFIG_VT)
>   #if defined(CONFIG_VGA_CONSOLE)
> -	conswitchp = &vga_con;
> +	vgacon_register_screen(&screen_info);
>   #endif
>   #endif
>   
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index fd975a4a52006..b1ea77d504615 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1293,7 +1293,7 @@ void __init setup_arch(char **cmdline_p)
>   #ifdef CONFIG_VT
>   #if defined(CONFIG_VGA_CONSOLE)
>   	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
> -		conswitchp = &vga_con;
> +		vgacon_register_screen(&screen_info);
>   #endif
>   #endif
>   	x86_init.oem.banner();
> diff --git a/drivers/firmware/pcdp.c b/drivers/firmware/pcdp.c
> index 715a45442d1cf..667a595373b2d 100644
> --- a/drivers/firmware/pcdp.c
> +++ b/drivers/firmware/pcdp.c
> @@ -72,7 +72,7 @@ setup_vga_console(struct pcdp_device *dev)
>   		return -ENODEV;
>   	}
>   
> -	conswitchp = &vga_con;
> +	vgacon_register_screen(&screen_info);
>   	printk(KERN_INFO "PCDP: VGA console\n");
>   	return 0;
>   #else
> diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
> index e25ba523892e5..3d7fedf27ffc1 100644
> --- a/drivers/video/console/vgacon.c
> +++ b/drivers/video/console/vgacon.c
> @@ -97,6 +97,8 @@ static int 		vga_video_font_height;
>   static int 		vga_scan_lines		__read_mostly;
>   static unsigned int 	vga_rolled_over; /* last vc_origin offset before wrap */
>   
> +static struct screen_info *vga_si;
> +
>   static bool vga_hardscroll_enabled;
>   static bool vga_hardscroll_user_enable = true;
>   
> @@ -161,8 +163,9 @@ static const char *vgacon_startup(void)
>   	u16 saved1, saved2;
>   	volatile u16 *p;
>   
> -	if (screen_info.orig_video_isVGA == VIDEO_TYPE_VLFB ||
> -	    screen_info.orig_video_isVGA == VIDEO_TYPE_EFI) {
> +	if (!vga_si ||
> +	    vga_si->orig_video_isVGA == VIDEO_TYPE_VLFB ||
> +	    vga_si->orig_video_isVGA == VIDEO_TYPE_EFI) {
>   	      no_vga:
>   #ifdef CONFIG_DUMMY_CONSOLE
>   		conswitchp = &dummy_con;
> @@ -172,29 +175,29 @@ static const char *vgacon_startup(void)
>   #endif
>   	}
>   
> -	/* boot_params.screen_info reasonably initialized? */
> -	if ((screen_info.orig_video_lines == 0) ||
> -	    (screen_info.orig_video_cols  == 0))
> +	/* vga_si reasonably initialized? */
> +	if ((vga_si->orig_video_lines == 0) ||
> +	    (vga_si->orig_video_cols  == 0))
>   		goto no_vga;
>   
>   	/* VGA16 modes are not handled by VGACON */
> -	if ((screen_info.orig_video_mode == 0x0D) ||	/* 320x200/4 */
> -	    (screen_info.orig_video_mode == 0x0E) ||	/* 640x200/4 */
> -	    (screen_info.orig_video_mode == 0x10) ||	/* 640x350/4 */
> -	    (screen_info.orig_video_mode == 0x12) ||	/* 640x480/4 */
> -	    (screen_info.orig_video_mode == 0x6A))	/* 800x600/4 (VESA) */
> +	if ((vga_si->orig_video_mode == 0x0D) ||	/* 320x200/4 */
> +	    (vga_si->orig_video_mode == 0x0E) ||	/* 640x200/4 */
> +	    (vga_si->orig_video_mode == 0x10) ||	/* 640x350/4 */
> +	    (vga_si->orig_video_mode == 0x12) ||	/* 640x480/4 */
> +	    (vga_si->orig_video_mode == 0x6A))	/* 800x600/4 (VESA) */
>   		goto no_vga;
>   
> -	vga_video_num_lines = screen_info.orig_video_lines;
> -	vga_video_num_columns = screen_info.orig_video_cols;
> +	vga_video_num_lines = vga_si->orig_video_lines;
> +	vga_video_num_columns = vga_si->orig_video_cols;
>   	vgastate.vgabase = NULL;
>   
> -	if (screen_info.orig_video_mode == 7) {
> +	if (vga_si->orig_video_mode == 7) {
>   		/* Monochrome display */
>   		vga_vram_base = 0xb0000;
>   		vga_video_port_reg = VGA_CRT_IM;
>   		vga_video_port_val = VGA_CRT_DM;
> -		if ((screen_info.orig_video_ega_bx & 0xff) != 0x10) {
> +		if ((vga_si->orig_video_ega_bx & 0xff) != 0x10) {
>   			static struct resource ega_console_resource =
>   			    { .name	= "ega",
>   			      .flags	= IORESOURCE_IO,
> @@ -231,12 +234,12 @@ static const char *vgacon_startup(void)
>   		vga_vram_base = 0xb8000;
>   		vga_video_port_reg = VGA_CRT_IC;
>   		vga_video_port_val = VGA_CRT_DC;
> -		if ((screen_info.orig_video_ega_bx & 0xff) != 0x10) {
> +		if ((vga_si->orig_video_ega_bx & 0xff) != 0x10) {
>   			int i;
>   
>   			vga_vram_size = 0x8000;
>   
> -			if (!screen_info.orig_video_isVGA) {
> +			if (!vga_si->orig_video_isVGA) {
>   				static struct resource ega_console_resource =
>   				    { .name	= "ega",
>   				      .flags	= IORESOURCE_IO,
> @@ -327,14 +330,14 @@ static const char *vgacon_startup(void)
>   	    || vga_video_type == VIDEO_TYPE_VGAC
>   	    || vga_video_type == VIDEO_TYPE_EGAM) {
>   		vga_hardscroll_enabled = vga_hardscroll_user_enable;
> -		vga_default_font_height = screen_info.orig_video_points;
> -		vga_video_font_height = screen_info.orig_video_points;
> +		vga_default_font_height = vga_si->orig_video_points;
> +		vga_video_font_height = vga_si->orig_video_points;
>   		/* This may be suboptimal but is a safe bet - go with it */
>   		vga_scan_lines =
>   		    vga_video_font_height * vga_video_num_lines;
>   	}
>   
> -	vgacon_xres = screen_info.orig_video_cols * VGA_FONTWIDTH;
> +	vgacon_xres = vga_si->orig_video_cols * VGA_FONTWIDTH;
>   	vgacon_yres = vga_scan_lines;
>   
>   	return display_desc;
> @@ -379,7 +382,7 @@ static void vgacon_init(struct vc_data *c, int init)
>   	/* Only set the default if the user didn't deliberately override it */
>   	if (global_cursor_default == -1)
>   		global_cursor_default =
> -			!(screen_info.flags & VIDEO_FLAGS_NOCURSOR);
> +			!(vga_si->flags & VIDEO_FLAGS_NOCURSOR);
>   }
>   
>   static void vgacon_deinit(struct vc_data *c)
> @@ -607,7 +610,7 @@ static int vgacon_switch(struct vc_data *c)
>   {
>   	int x = c->vc_cols * VGA_FONTWIDTH;
>   	int y = c->vc_rows * c->vc_cell_height;
> -	int rows = screen_info.orig_video_lines * vga_default_font_height/
> +	int rows = vga_si->orig_video_lines * vga_default_font_height/
>   		c->vc_cell_height;
>   	/*
>   	 * We need to save screen size here as it's the only way
> @@ -627,7 +630,7 @@ static int vgacon_switch(struct vc_data *c)
>   
>   		if ((vgacon_xres != x || vgacon_yres != y) &&
>   		    (!(vga_video_num_columns % 2) &&
> -		     vga_video_num_columns <= screen_info.orig_video_cols &&
> +		     vga_video_num_columns <= vga_si->orig_video_cols &&
>   		     vga_video_num_lines <= rows))
>   			vgacon_doresize(c, c->vc_cols, c->vc_rows);
>   	}
> @@ -1074,13 +1077,13 @@ static int vgacon_resize(struct vc_data *c, unsigned int width,
>   		 * Ho ho!  Someone (svgatextmode, eh?) may have reprogrammed
>   		 * the video mode!  Set the new defaults then and go away.
>   		 */
> -		screen_info.orig_video_cols = width;
> -		screen_info.orig_video_lines = height;
> +		vga_si->orig_video_cols = width;
> +		vga_si->orig_video_lines = height;
>   		vga_default_font_height = c->vc_cell_height;
>   		return 0;
>   	}
> -	if (width % 2 || width > screen_info.orig_video_cols ||
> -	    height > (screen_info.orig_video_lines * vga_default_font_height)/
> +	if (width % 2 || width > vga_si->orig_video_cols ||
> +	    height > (vga_si->orig_video_lines * vga_default_font_height)/
>   	    c->vc_cell_height)
>   		return -EINVAL;
>   
> @@ -1110,8 +1113,8 @@ static void vgacon_save_screen(struct vc_data *c)
>   		 * console initialization routines.
>   		 */
>   		vga_bootup_console = 1;
> -		c->state.x = screen_info.orig_x;
> -		c->state.y = screen_info.orig_y;
> +		c->state.x = vga_si->orig_x;
> +		c->state.y = vga_si->orig_y;
>   	}
>   
>   	/* We can't copy in more than the size of the video buffer,
> @@ -1204,4 +1207,13 @@ const struct consw vga_con = {
>   };
>   EXPORT_SYMBOL(vga_con);
>   
> +void vgacon_register_screen(struct screen_info *si)
> +{
> +	if (!si || vga_si)
> +		return;
> +
> +	conswitchp = &vga_con;
> +	vga_si = si;
> +}
> +
>   MODULE_LICENSE("GPL");
> diff --git a/include/linux/console.h b/include/linux/console.h
> index d3195664baa5a..5f900210e689e 100644
> --- a/include/linux/console.h
> +++ b/include/linux/console.h
> @@ -101,6 +101,13 @@ extern const struct consw dummy_con;	/* dummy console buffer */
>   extern const struct consw vga_con;	/* VGA text console */
>   extern const struct consw newport_con;	/* SGI Newport console  */
>   
> +struct screen_info;
> +#ifdef CONFIG_VGA_CONSOLE
> +void vgacon_register_screen(struct screen_info *si);
> +#else
> +static inline void vgacon_register_screen(struct screen_info *si) { }
> +#endif
> +
>   int con_is_bound(const struct consw *csw);
>   int do_unregister_con_driver(const struct consw *csw);
>   int do_take_over_console(const struct consw *sw, int first, int last, int deflt);
  

Patch

diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index b4d2297765c02..d73b685fe9852 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -655,7 +655,7 @@  setup_arch(char **cmdline_p)
 
 #ifdef CONFIG_VT
 #if defined(CONFIG_VGA_CONSOLE)
-	conswitchp = &vga_con;
+	vgacon_register_screen(&screen_info);
 #endif
 #endif
 
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 40326a35a179b..5d8a7fb3eba45 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1192,7 +1192,7 @@  void __init setup_arch(char **cmdline_p)
 
 #ifdef CONFIG_VT
 #if defined(CONFIG_VGA_CONSOLE)
-	conswitchp = &vga_con;
+	vgacon_register_screen(&screen_info);
 #endif
 #endif
 
diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index d2c66efdde560..2c9283fcd3759 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -619,7 +619,7 @@  setup_arch (char **cmdline_p)
 		 * memory so we can avoid this problem.
 		 */
 		if (efi_mem_type(0xA0000) != EFI_CONVENTIONAL_MEMORY)
-			conswitchp = &vga_con;
+			vgacon_register_screen(&screen_info);
 # endif
 	}
 #endif
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 1aba7dc95132c..6c3fae62a9f6b 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -794,7 +794,7 @@  void __init setup_arch(char **cmdline_p)
 
 #if defined(CONFIG_VT)
 #if defined(CONFIG_VGA_CONSOLE)
-	conswitchp = &vga_con;
+	vgacon_register_screen(&screen_info);
 #endif
 #endif
 
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index fd975a4a52006..b1ea77d504615 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1293,7 +1293,7 @@  void __init setup_arch(char **cmdline_p)
 #ifdef CONFIG_VT
 #if defined(CONFIG_VGA_CONSOLE)
 	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
-		conswitchp = &vga_con;
+		vgacon_register_screen(&screen_info);
 #endif
 #endif
 	x86_init.oem.banner();
diff --git a/drivers/firmware/pcdp.c b/drivers/firmware/pcdp.c
index 715a45442d1cf..667a595373b2d 100644
--- a/drivers/firmware/pcdp.c
+++ b/drivers/firmware/pcdp.c
@@ -72,7 +72,7 @@  setup_vga_console(struct pcdp_device *dev)
 		return -ENODEV;
 	}
 
-	conswitchp = &vga_con;
+	vgacon_register_screen(&screen_info);
 	printk(KERN_INFO "PCDP: VGA console\n");
 	return 0;
 #else
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index e25ba523892e5..3d7fedf27ffc1 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -97,6 +97,8 @@  static int 		vga_video_font_height;
 static int 		vga_scan_lines		__read_mostly;
 static unsigned int 	vga_rolled_over; /* last vc_origin offset before wrap */
 
+static struct screen_info *vga_si;
+
 static bool vga_hardscroll_enabled;
 static bool vga_hardscroll_user_enable = true;
 
@@ -161,8 +163,9 @@  static const char *vgacon_startup(void)
 	u16 saved1, saved2;
 	volatile u16 *p;
 
-	if (screen_info.orig_video_isVGA == VIDEO_TYPE_VLFB ||
-	    screen_info.orig_video_isVGA == VIDEO_TYPE_EFI) {
+	if (!vga_si ||
+	    vga_si->orig_video_isVGA == VIDEO_TYPE_VLFB ||
+	    vga_si->orig_video_isVGA == VIDEO_TYPE_EFI) {
 	      no_vga:
 #ifdef CONFIG_DUMMY_CONSOLE
 		conswitchp = &dummy_con;
@@ -172,29 +175,29 @@  static const char *vgacon_startup(void)
 #endif
 	}
 
-	/* boot_params.screen_info reasonably initialized? */
-	if ((screen_info.orig_video_lines == 0) ||
-	    (screen_info.orig_video_cols  == 0))
+	/* vga_si reasonably initialized? */
+	if ((vga_si->orig_video_lines == 0) ||
+	    (vga_si->orig_video_cols  == 0))
 		goto no_vga;
 
 	/* VGA16 modes are not handled by VGACON */
-	if ((screen_info.orig_video_mode == 0x0D) ||	/* 320x200/4 */
-	    (screen_info.orig_video_mode == 0x0E) ||	/* 640x200/4 */
-	    (screen_info.orig_video_mode == 0x10) ||	/* 640x350/4 */
-	    (screen_info.orig_video_mode == 0x12) ||	/* 640x480/4 */
-	    (screen_info.orig_video_mode == 0x6A))	/* 800x600/4 (VESA) */
+	if ((vga_si->orig_video_mode == 0x0D) ||	/* 320x200/4 */
+	    (vga_si->orig_video_mode == 0x0E) ||	/* 640x200/4 */
+	    (vga_si->orig_video_mode == 0x10) ||	/* 640x350/4 */
+	    (vga_si->orig_video_mode == 0x12) ||	/* 640x480/4 */
+	    (vga_si->orig_video_mode == 0x6A))	/* 800x600/4 (VESA) */
 		goto no_vga;
 
-	vga_video_num_lines = screen_info.orig_video_lines;
-	vga_video_num_columns = screen_info.orig_video_cols;
+	vga_video_num_lines = vga_si->orig_video_lines;
+	vga_video_num_columns = vga_si->orig_video_cols;
 	vgastate.vgabase = NULL;
 
-	if (screen_info.orig_video_mode == 7) {
+	if (vga_si->orig_video_mode == 7) {
 		/* Monochrome display */
 		vga_vram_base = 0xb0000;
 		vga_video_port_reg = VGA_CRT_IM;
 		vga_video_port_val = VGA_CRT_DM;
-		if ((screen_info.orig_video_ega_bx & 0xff) != 0x10) {
+		if ((vga_si->orig_video_ega_bx & 0xff) != 0x10) {
 			static struct resource ega_console_resource =
 			    { .name	= "ega",
 			      .flags	= IORESOURCE_IO,
@@ -231,12 +234,12 @@  static const char *vgacon_startup(void)
 		vga_vram_base = 0xb8000;
 		vga_video_port_reg = VGA_CRT_IC;
 		vga_video_port_val = VGA_CRT_DC;
-		if ((screen_info.orig_video_ega_bx & 0xff) != 0x10) {
+		if ((vga_si->orig_video_ega_bx & 0xff) != 0x10) {
 			int i;
 
 			vga_vram_size = 0x8000;
 
-			if (!screen_info.orig_video_isVGA) {
+			if (!vga_si->orig_video_isVGA) {
 				static struct resource ega_console_resource =
 				    { .name	= "ega",
 				      .flags	= IORESOURCE_IO,
@@ -327,14 +330,14 @@  static const char *vgacon_startup(void)
 	    || vga_video_type == VIDEO_TYPE_VGAC
 	    || vga_video_type == VIDEO_TYPE_EGAM) {
 		vga_hardscroll_enabled = vga_hardscroll_user_enable;
-		vga_default_font_height = screen_info.orig_video_points;
-		vga_video_font_height = screen_info.orig_video_points;
+		vga_default_font_height = vga_si->orig_video_points;
+		vga_video_font_height = vga_si->orig_video_points;
 		/* This may be suboptimal but is a safe bet - go with it */
 		vga_scan_lines =
 		    vga_video_font_height * vga_video_num_lines;
 	}
 
-	vgacon_xres = screen_info.orig_video_cols * VGA_FONTWIDTH;
+	vgacon_xres = vga_si->orig_video_cols * VGA_FONTWIDTH;
 	vgacon_yres = vga_scan_lines;
 
 	return display_desc;
@@ -379,7 +382,7 @@  static void vgacon_init(struct vc_data *c, int init)
 	/* Only set the default if the user didn't deliberately override it */
 	if (global_cursor_default == -1)
 		global_cursor_default =
-			!(screen_info.flags & VIDEO_FLAGS_NOCURSOR);
+			!(vga_si->flags & VIDEO_FLAGS_NOCURSOR);
 }
 
 static void vgacon_deinit(struct vc_data *c)
@@ -607,7 +610,7 @@  static int vgacon_switch(struct vc_data *c)
 {
 	int x = c->vc_cols * VGA_FONTWIDTH;
 	int y = c->vc_rows * c->vc_cell_height;
-	int rows = screen_info.orig_video_lines * vga_default_font_height/
+	int rows = vga_si->orig_video_lines * vga_default_font_height/
 		c->vc_cell_height;
 	/*
 	 * We need to save screen size here as it's the only way
@@ -627,7 +630,7 @@  static int vgacon_switch(struct vc_data *c)
 
 		if ((vgacon_xres != x || vgacon_yres != y) &&
 		    (!(vga_video_num_columns % 2) &&
-		     vga_video_num_columns <= screen_info.orig_video_cols &&
+		     vga_video_num_columns <= vga_si->orig_video_cols &&
 		     vga_video_num_lines <= rows))
 			vgacon_doresize(c, c->vc_cols, c->vc_rows);
 	}
@@ -1074,13 +1077,13 @@  static int vgacon_resize(struct vc_data *c, unsigned int width,
 		 * Ho ho!  Someone (svgatextmode, eh?) may have reprogrammed
 		 * the video mode!  Set the new defaults then and go away.
 		 */
-		screen_info.orig_video_cols = width;
-		screen_info.orig_video_lines = height;
+		vga_si->orig_video_cols = width;
+		vga_si->orig_video_lines = height;
 		vga_default_font_height = c->vc_cell_height;
 		return 0;
 	}
-	if (width % 2 || width > screen_info.orig_video_cols ||
-	    height > (screen_info.orig_video_lines * vga_default_font_height)/
+	if (width % 2 || width > vga_si->orig_video_cols ||
+	    height > (vga_si->orig_video_lines * vga_default_font_height)/
 	    c->vc_cell_height)
 		return -EINVAL;
 
@@ -1110,8 +1113,8 @@  static void vgacon_save_screen(struct vc_data *c)
 		 * console initialization routines.
 		 */
 		vga_bootup_console = 1;
-		c->state.x = screen_info.orig_x;
-		c->state.y = screen_info.orig_y;
+		c->state.x = vga_si->orig_x;
+		c->state.y = vga_si->orig_y;
 	}
 
 	/* We can't copy in more than the size of the video buffer,
@@ -1204,4 +1207,13 @@  const struct consw vga_con = {
 };
 EXPORT_SYMBOL(vga_con);
 
+void vgacon_register_screen(struct screen_info *si)
+{
+	if (!si || vga_si)
+		return;
+
+	conswitchp = &vga_con;
+	vga_si = si;
+}
+
 MODULE_LICENSE("GPL");
diff --git a/include/linux/console.h b/include/linux/console.h
index d3195664baa5a..5f900210e689e 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -101,6 +101,13 @@  extern const struct consw dummy_con;	/* dummy console buffer */
 extern const struct consw vga_con;	/* VGA text console */
 extern const struct consw newport_con;	/* SGI Newport console  */
 
+struct screen_info;
+#ifdef CONFIG_VGA_CONSOLE
+void vgacon_register_screen(struct screen_info *si);
+#else
+static inline void vgacon_register_screen(struct screen_info *si) { }
+#endif
+
 int con_is_bound(const struct consw *csw);
 int do_unregister_con_driver(const struct consw *csw);
 int do_take_over_console(const struct consw *sw, int first, int last, int deflt);