From: Thomas Zimmermann Date: Tue, 7 Apr 2026 09:23:14 +0000 (+0200) Subject: lib/fonts: Provide helpers for calculating glyph pitch and size X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=97df8960240afc47c2349d008b0993e7727bbda5;p=thirdparty%2Fkernel%2Flinux.git lib/fonts: Provide helpers for calculating glyph pitch and size Implement pitch and size calculation for a single font glyph in the new helpers font_glyph_pitch() and font_glyph_size(). Replace the instances where the calculations are open-coded. Note that in the case of fbcon console rotation, the parameters for a glyph's width and height might be reversed. This is intentional. v2: - fix typos in commit message Signed-off-by: Thomas Zimmermann Signed-off-by: Helge Deller --- diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 3c90856488cdc..5c9fec4f99a0a 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -71,7 +71,6 @@ * by Adam Tla/lka , Aug 2006 */ -#include #include #include #include @@ -244,7 +243,7 @@ enum { */ unsigned int vc_font_pitch(const struct vc_font *font) { - return DIV_ROUND_UP(font->width, 8); + return font_glyph_pitch(font->width); } EXPORT_SYMBOL_GPL(vc_font_pitch); @@ -261,7 +260,7 @@ EXPORT_SYMBOL_GPL(vc_font_pitch); */ unsigned int vc_font_size(const struct vc_font *font) { - return font->height * vc_font_pitch(font) * font->charcount; + return font_glyph_size(font->width, font->height) * font->charcount; } EXPORT_SYMBOL_GPL(vc_font_size); diff --git a/drivers/video/fbdev/core/fbcon_ccw.c b/drivers/video/fbdev/core/fbcon_ccw.c index 2f394b5a17f79..96ef449ee6ac8 100644 --- a/drivers/video/fbdev/core/fbcon_ccw.c +++ b/drivers/video/fbdev/core/fbcon_ccw.c @@ -26,7 +26,7 @@ static void ccw_update_attr(u8 *dst, u8 *src, int attribute, struct vc_data *vc) { int i, j, offset = (vc->vc_font.height < 10) ? 1 : 2; - int width = (vc->vc_font.height + 7) >> 3; + int width = font_glyph_pitch(vc->vc_font.height); int mod = vc->vc_font.height % 8; u8 c, msk = ~(0xff << offset), msk1 = 0; @@ -101,7 +101,7 @@ static inline void ccw_putcs_aligned(struct vc_data *vc, struct fb_info *info, { struct fbcon_par *par = info->fbcon_par; u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff; - u32 idx = (vc->vc_font.height + 7) >> 3; + u32 idx = font_glyph_pitch(vc->vc_font.height); u8 *src; while (cnt--) { @@ -131,7 +131,7 @@ static void ccw_putcs(struct vc_data *vc, struct fb_info *info, { struct fb_image image; struct fbcon_par *par = info->fbcon_par; - u32 width = (vc->vc_font.height + 7)/8; + u32 width = font_glyph_pitch(vc->vc_font.height); u32 cellsize = width * vc->vc_font.width; u32 maxcnt = info->pixmap.size/cellsize; u32 scan_align = info->pixmap.scan_align - 1; @@ -223,7 +223,8 @@ static void ccw_cursor(struct vc_data *vc, struct fb_info *info, bool enable, struct fb_cursor cursor; struct fbcon_par *par = info->fbcon_par; unsigned short charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff; - int w = (vc->vc_font.height + 7) >> 3, c; + int w = font_glyph_pitch(vc->vc_font.height); + int c; int y = real_y(par->p, vc->state.y); int attribute, use_sw = vc->vc_cursor_type & CUR_SW; int err = 1, dx, dy; @@ -297,7 +298,7 @@ static void ccw_cursor(struct vc_data *vc, struct fb_info *info, bool enable, char *tmp, *mask = kmalloc_array(w, vc->vc_font.width, GFP_ATOMIC); int cur_height, size, i = 0; - int width = (vc->vc_font.width + 7)/8; + int width = font_glyph_pitch(vc->vc_font.width); if (!mask) return; diff --git a/drivers/video/fbdev/core/fbcon_cw.c b/drivers/video/fbdev/core/fbcon_cw.c index 3c3ad3471ec4b..ea712654edae3 100644 --- a/drivers/video/fbdev/core/fbcon_cw.c +++ b/drivers/video/fbdev/core/fbcon_cw.c @@ -26,7 +26,7 @@ static void cw_update_attr(u8 *dst, u8 *src, int attribute, struct vc_data *vc) { int i, j, offset = (vc->vc_font.height < 10) ? 1 : 2; - int width = (vc->vc_font.height + 7) >> 3; + int width = font_glyph_pitch(vc->vc_font.height); u8 c, msk = ~(0xff >> offset); for (i = 0; i < vc->vc_font.width; i++) { @@ -86,7 +86,7 @@ static inline void cw_putcs_aligned(struct vc_data *vc, struct fb_info *info, { struct fbcon_par *par = info->fbcon_par; u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff; - u32 idx = (vc->vc_font.height + 7) >> 3; + u32 idx = font_glyph_pitch(vc->vc_font.height); u8 *src; while (cnt--) { @@ -116,7 +116,7 @@ static void cw_putcs(struct vc_data *vc, struct fb_info *info, { struct fb_image image; struct fbcon_par *par = info->fbcon_par; - u32 width = (vc->vc_font.height + 7)/8; + u32 width = font_glyph_pitch(vc->vc_font.height); u32 cellsize = width * vc->vc_font.width; u32 maxcnt = info->pixmap.size/cellsize; u32 scan_align = info->pixmap.scan_align - 1; @@ -206,7 +206,8 @@ static void cw_cursor(struct vc_data *vc, struct fb_info *info, bool enable, struct fb_cursor cursor; struct fbcon_par *par = info->fbcon_par; unsigned short charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff; - int w = (vc->vc_font.height + 7) >> 3, c; + int w = font_glyph_pitch(vc->vc_font.height); + int c; int y = real_y(par->p, vc->state.y); int attribute, use_sw = vc->vc_cursor_type & CUR_SW; int err = 1, dx, dy; @@ -280,7 +281,7 @@ static void cw_cursor(struct vc_data *vc, struct fb_info *info, bool enable, char *tmp, *mask = kmalloc_array(w, vc->vc_font.width, GFP_ATOMIC); int cur_height, size, i = 0; - int width = (vc->vc_font.width + 7)/8; + int width = font_glyph_pitch(vc->vc_font.width); if (!mask) return; diff --git a/drivers/video/fbdev/core/fbcon_rotate.c b/drivers/video/fbdev/core/fbcon_rotate.c index 5348f6c6f57c7..18575c5182db3 100644 --- a/drivers/video/fbdev/core/fbcon_rotate.c +++ b/drivers/video/fbdev/core/fbcon_rotate.c @@ -33,14 +33,12 @@ int fbcon_rotate_font(struct fb_info *info, struct vc_data *vc) src = par->fontdata = vc->vc_font.data; par->cur_rotate = par->p->con_rotate; len = vc->vc_font.charcount; - s_cellsize = ((vc->vc_font.width + 7)/8) * - vc->vc_font.height; + s_cellsize = font_glyph_size(vc->vc_font.width, vc->vc_font.height); d_cellsize = s_cellsize; if (par->rotate == FB_ROTATE_CW || par->rotate == FB_ROTATE_CCW) - d_cellsize = ((vc->vc_font.height + 7)/8) * - vc->vc_font.width; + d_cellsize = font_glyph_size(vc->vc_font.height, vc->vc_font.width); if (info->fbops->fb_sync) info->fbops->fb_sync(info); diff --git a/drivers/video/fbdev/core/fbcon_ud.c b/drivers/video/fbdev/core/fbcon_ud.c index 6fc30cad5b19b..f7cd89c42b01c 100644 --- a/drivers/video/fbdev/core/fbcon_ud.c +++ b/drivers/video/fbdev/core/fbcon_ud.c @@ -26,7 +26,7 @@ static void ud_update_attr(u8 *dst, u8 *src, int attribute, struct vc_data *vc) { int i, offset = (vc->vc_font.height < 10) ? 1 : 2; - int width = (vc->vc_font.width + 7) >> 3; + int width = font_glyph_pitch(vc->vc_font.width); unsigned int cellsize = vc->vc_font.height * width; u8 c; @@ -153,7 +153,7 @@ static void ud_putcs(struct vc_data *vc, struct fb_info *info, { struct fb_image image; struct fbcon_par *par = info->fbcon_par; - u32 width = (vc->vc_font.width + 7)/8; + u32 width = font_glyph_pitch(vc->vc_font.width); u32 cellsize = width * vc->vc_font.height; u32 maxcnt = info->pixmap.size/cellsize; u32 scan_align = info->pixmap.scan_align - 1; @@ -253,7 +253,8 @@ static void ud_cursor(struct vc_data *vc, struct fb_info *info, bool enable, struct fb_cursor cursor; struct fbcon_par *par = info->fbcon_par; unsigned short charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff; - int w = (vc->vc_font.width + 7) >> 3, c; + int w = font_glyph_pitch(vc->vc_font.width); + int c; int y = real_y(par->p, vc->state.y); int attribute, use_sw = vc->vc_cursor_type & CUR_SW; int err = 1, dx, dy; diff --git a/include/linux/font.h b/include/linux/font.h index 5401f07dd6ce8..3bd49d914b22f 100644 --- a/include/linux/font.h +++ b/include/linux/font.h @@ -11,10 +11,50 @@ #ifndef _VIDEO_FONT_H #define _VIDEO_FONT_H +#include #include struct console_font; +/* + * Glyphs + */ + +/** + * font_glyph_pitch - Calculates the number of bytes per scanline + * @width: The glyph width in bits per scanline + * + * A glyph's pitch is the number of bytes in a single scanline, rounded + * up to the next full byte. The parameter @width receives the number + * of visible bits per scanline. For example, if width is 14 bytes per + * scanline, the pitch is 2 bytes per scanline. If width is 8 bits per + * scanline, the pitch is 1 byte per scanline. + * + * Returns: + * The number of bytes in a single scanline of the glyph + */ +static inline unsigned int font_glyph_pitch(unsigned int width) +{ + return DIV_ROUND_UP(width, 8); +} + +/** + * font_glyph_size - Calculates the number of bytes per glyph + * @width: The glyph width in bits per scanline + * @vpitch: The number of scanlines in the glyph + * + * The number of bytes in a glyph depends on the pitch and the number + * of scanlines. font_glyph_size automatically calculates the pitch + * from the given width. The parameter @vpitch gives the number of + * scanlines, which is usually the glyph's height in scanlines. Fonts + * coming from user space can sometimes have a different vertical pitch + * with empty scanlines between two adjacent glyphs. + */ +static inline unsigned int font_glyph_size(unsigned int width, unsigned int vpitch) +{ + return font_glyph_pitch(width) * vpitch; +} + /* * font_data_t and helpers */ diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c index 5938f542906b0..f5d5333450a02 100644 --- a/lib/fonts/fonts.c +++ b/lib/fonts/fonts.c @@ -26,7 +26,7 @@ #include "font.h" -#define console_font_pitch(font) DIV_ROUND_UP((font)->width, 8) +#define console_font_pitch(font) font_glyph_pitch((font)->width) /* * Helpers for font_data_t