[PATCH 07/13] lib/fonts: Store font data as font_data_t; update consoles
From: Thomas Zimmermann
Date: Wed Feb 18 2026 - 03:42:33 EST
Store font data as pointer to font_data_t instead of unsigned char.
Update consoles.
Pointers to font data refer to the raw data. There is a hidden header
before the data that contains additional state. Document the existing
layout and semantics of font_data_t.
The data field in struct vc_font can be used by any console. Therefore
it still points to plain data without the additional header. Fbcon sets
its value from struct fbcon_display.fontdata. Hence, update the size
test in fbcon_resize() to use struct fbcon_display.fontdata instead of
struct vc_font.data.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/video/console/newport_con.c | 17 ++++++-----
drivers/video/fbdev/core/fbcon.c | 44 ++++++++++++++++-----------
drivers/video/fbdev/core/fbcon.h | 3 +-
include/linux/font.h | 47 ++++++++++++++++++++++++++++-
4 files changed, 84 insertions(+), 27 deletions(-)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 6e9d61791888..fcf76f65b06e 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -33,9 +33,9 @@
#define NEWPORT_LEN 0x10000
-#define FONT_DATA ((unsigned char *)font_vga_8x16.data)
+#define FONT_DATA font_vga_8x16.data
-static unsigned char *font_data[MAX_NR_CONSOLES];
+static font_data_t *font_data[MAX_NR_CONSOLES];
static struct newport_regs *npregs;
static unsigned long newport_addr;
@@ -370,9 +370,9 @@ static void newport_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
static void newport_putc(struct vc_data *vc, u16 charattr, unsigned int ypos,
unsigned int xpos)
{
- unsigned char *p;
+ const unsigned char *p;
- p = &font_data[vc->vc_num][(charattr & 0xff) << 4];
+ p = &font_data_buf(font_data[vc->vc_num])[(charattr & 0xff) << 4];
charattr = (charattr >> 8) & 0xff;
xpos <<= 3;
ypos <<= 4;
@@ -400,7 +400,7 @@ static void newport_putcs(struct vc_data *vc, const u16 *s,
unsigned int count, unsigned int ypos,
unsigned int xpos)
{
- unsigned char *p;
+ const unsigned char *p;
unsigned int i;
u16 charattr;
@@ -424,7 +424,7 @@ static void newport_putcs(struct vc_data *vc, const u16 *s,
NPORT_DMODE0_L32);
for (i = 0; i < count; i++, xpos += 8) {
- p = &font_data[vc->vc_num][(scr_readw(s++) & 0xff) << 4];
+ p = &font_data_buf(font_data[vc->vc_num])[(scr_readw(s++) & 0xff) << 4];
newport_wait(npregs);
@@ -503,7 +503,8 @@ static int newport_set_font(int unit, const struct console_font *op,
int h = op->height;
int size = h * op->charcount;
int i;
- unsigned char *new_data, *data = op->data, *p;
+ font_data_t *new_data;
+ unsigned char *data = op->data, *p;
/* ladis: when I grow up, there will be a day... and more sizes will
* be supported ;-) */
@@ -519,7 +520,7 @@ static int newport_set_font(int unit, const struct console_font *op,
REFCOUNT(new_data) = 0; /* usage counter */
FNTSUM(new_data) = 0;
- p = new_data;
+ p = (unsigned char *)font_data_buf(new_data);
for (i = 0; i < op->charcount; i++) {
memcpy(p, data, h);
data += 32;
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 96cf890aa0c9..73f2757155e6 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1019,8 +1019,10 @@ static const char *fbcon_startup(void)
info->pixmap.blit_y);
vc->vc_font.width = font->width;
vc->vc_font.height = font->height;
- vc->vc_font.data = (void *)(p->fontdata = font->data);
+ vc->vc_font.data = font_data_buf(font->data);
vc->vc_font.charcount = font->charcount;
+
+ p->fontdata = font->data;
}
cols = FBCON_SWAP(par->rotate, info->var.xres, info->var.yres);
@@ -1077,11 +1079,12 @@ static void fbcon_init(struct vc_data *vc, bool init)
if (t->fontdata) {
struct vc_data *fvc = vc_cons[fg_console].d;
- vc->vc_font.data = (void *)(p->fontdata =
- fvc->vc_font.data);
+ vc->vc_font.data = fvc->vc_font.data;
vc->vc_font.width = fvc->vc_font.width;
vc->vc_font.height = fvc->vc_font.height;
vc->vc_font.charcount = fvc->vc_font.charcount;
+
+ p->fontdata = t->fontdata;
p->userfont = t->userfont;
if (p->userfont)
@@ -1096,8 +1099,10 @@ static void fbcon_init(struct vc_data *vc, bool init)
info->pixmap.blit_y);
vc->vc_font.width = font->width;
vc->vc_font.height = font->height;
- vc->vc_font.data = (void *)(p->fontdata = font->data);
+ vc->vc_font.data = font_data_buf(font->data);
vc->vc_font.charcount = font->charcount;
+
+ p->fontdata = font->data;
}
}
@@ -1408,11 +1413,12 @@ static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var,
svc = *default_mode;
t = &fb_display[svc->vc_num];
- if (!vc->vc_font.data) {
- vc->vc_font.data = (void *)(p->fontdata = t->fontdata);
+ if (!p->fontdata) {
+ vc->vc_font.data = font_data_buf(t->fontdata);
vc->vc_font.width = (*default_mode)->vc_font.width;
vc->vc_font.height = (*default_mode)->vc_font.height;
vc->vc_font.charcount = (*default_mode)->vc_font.charcount;
+ p->fontdata = t->fontdata;
p->userfont = t->userfont;
if (p->userfont)
REFCOUNT(p->fontdata)++;
@@ -2052,7 +2058,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
struct fb_var_screeninfo var = info->var;
int x_diff, y_diff, virt_w, virt_h, virt_fw, virt_fh;
- if (p->userfont && FNTSIZE(vc->vc_font.data)) {
+ if (p->userfont && FNTSIZE(p->fontdata)) {
unsigned int size = vc_font_size(&vc->vc_font);
/*
@@ -2062,7 +2068,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
* charcount can change and cannot be used to determine the
* font data allocated size.
*/
- if (!size || size > FNTSIZE(vc->vc_font.data))
+ if (!size || size > FNTSIZE(p->fontdata))
return -EINVAL;
}
@@ -2286,7 +2292,8 @@ static bool fbcon_blank(struct vc_data *vc, enum vesa_blank_mode blank,
static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigned int vpitch)
{
- const u8 *fontdata = vc->vc_font.data;
+ struct fbcon_display *p = &fb_display[vc->vc_num];
+ font_data_t *fontdata = p->fontdata;
u8 *data = font->data;
int i, j;
@@ -2411,16 +2418,18 @@ static void set_vc_hi_font(struct vc_data *vc, bool set)
}
static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
- const u8 * data, int userfont)
+ font_data_t *data, int userfont)
{
struct fb_info *info = fbcon_info_from_console(vc->vc_num);
struct fbcon_par *par = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num];
int resize, ret, old_userfont, old_width, old_height, old_charcount;
+ font_data_t *old_fontdata = p->fontdata;
const u8 *old_data = vc->vc_font.data;
resize = (w != vc->vc_font.width) || (h != vc->vc_font.height);
- vc->vc_font.data = (void *)(p->fontdata = data);
+ p->fontdata = data;
+ vc->vc_font.data = font_data_buf(p->fontdata);
old_userfont = p->userfont;
if ((p->userfont = userfont))
REFCOUNT(data)++;
@@ -2453,12 +2462,12 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
update_screen(vc);
}
- if (old_userfont && (--REFCOUNT(old_data) == 0))
- kfree(old_data - FONT_EXTRA_WORDS * sizeof(int));
+ if (old_userfont && (--REFCOUNT(old_fontdata) == 0))
+ kfree(old_fontdata - FONT_EXTRA_WORDS * sizeof(int));
return 0;
err_out:
- p->fontdata = old_data;
+ p->fontdata = old_fontdata;
vc->vc_font.data = old_data;
if (userfont) {
@@ -2488,7 +2497,8 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
int h = font->height;
int size, alloc_size;
int i, csum;
- u8 *new_data, *data = font->data;
+ font_data_t *new_data;
+ u8 *data = font->data;
int pitch = PITCH(font->width);
/* Is there a reason why fbconsole couldn't handle any charcount >256?
@@ -2527,13 +2537,13 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
if (!new_data)
return -ENOMEM;
- memset(new_data, 0, FONT_EXTRA_WORDS * sizeof(int));
+ memset((u8 *)new_data, 0, FONT_EXTRA_WORDS * sizeof(int));
new_data += FONT_EXTRA_WORDS * sizeof(int);
FNTSIZE(new_data) = size;
REFCOUNT(new_data) = 0; /* usage counter */
for (i=0; i< charcount; i++) {
- memcpy(new_data + i*h*pitch, data + i*vpitch*pitch, h*pitch);
+ memcpy((u8 *)new_data + i * h * pitch, data + i * vpitch * pitch, h * pitch);
}
/* Since linux has a nice crc32 function use it for counting font
diff --git a/drivers/video/fbdev/core/fbcon.h b/drivers/video/fbdev/core/fbcon.h
index 3f4386a40237..d26ee7860cf5 100644
--- a/drivers/video/fbdev/core/fbcon.h
+++ b/drivers/video/fbdev/core/fbcon.h
@@ -11,6 +11,7 @@
#ifndef _VIDEO_FBCON_H
#define _VIDEO_FBCON_H
+#include <linux/font.h>
#include <linux/types.h>
#include <linux/vt_buffer.h>
#include <linux/vt_kern.h>
@@ -25,7 +26,7 @@
struct fbcon_display {
/* Filled in by the low-level console driver */
- const u_char *fontdata;
+ font_data_t *fontdata;
int userfont; /* != 0 if fontdata kmalloc()ed */
#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
u_short scrollmode; /* Scroll Method, use fb_scrollmode() */
diff --git a/include/linux/font.h b/include/linux/font.h
index d929c5fa32ca..4ff8d52e59c3 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -13,12 +13,57 @@
#include <linux/types.h>
+/*
+ * font_data_t and helpers
+ */
+
+/**
+ * font_data_t - Raw font data
+ *
+ * Values of type font_data_t store a pointer to raw font data. The format
+ * is monochrome. Each bit sets a pixel of a stored glyph. Font data does
+ * not store geometry information for the individual glyphs. Users of the
+ * font have to store glyph size, pitch and characer count separately.
+ *
+ * Font data in font_data_t is not equivalent to raw u8. Each pointer stores
+ * an additional hidden header before the fotn data. The layout is
+ *
+ * +------+-----------------------------+
+ * | -16 | CRC32 Checksum (optional) |
+ * | -12 | <Unused> |
+ * | -8 | Number of data bytes |
+ * | -4 | Reference count |
+ * +------+-----------------------------+
+ * | 0 | Data buffer |
+ * | ... | |
+ * +------+-----------------------------+
+ *
+ * Use helpers to access font_data_t. Use font_data_buf() to get the stored data.
+ */
+typedef const unsigned char font_data_t;
+
+/**
+ * font_data_buf() - Returns the font data as raw bytes
+ * @fd: The font data
+ *
+ * Returns:
+ * The raw font data. The provided buffer is read-only.
+ */
+static inline const unsigned char *font_data_buf(font_data_t *fd)
+{
+ return (const unsigned char *)fd;
+}
+
+/*
+ * Font lookup
+ */
+
struct font_desc {
int idx;
const char *name;
unsigned int width, height;
unsigned int charcount;
- const void *data;
+ font_data_t *data;
int pref;
};
--
2.52.0