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

Arnd Bergmann
2023-07-19T12:41:24Z

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(-)

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);
--
2.39.2