From: Thomas Zimmermann <tzimmermann@suse.de>
To: deller@gmx.de, simona@ffwll.ch
Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
sashiko-reviews@lists.linux.dev,
Thomas Zimmermann <tzimmermann@suse.de>
Subject: [PATCH 1/6] fbcon: Use unsigned char for glyph data
Date: Tue, 27 Oct 2026 14:27:16 +0100 [thread overview]
Message-ID: <20261027133646.297856-2-tzimmermann@suse.de> (raw)
In-Reply-To: <20261027133646.297856-1-tzimmermann@suse.de>
Represent glyph data as unsigned char, as done by font_data_t. Convert
all related code. Also declare source buffers with glyph data as const
because internal fonts reside in read-only memory. Avoid writing them.
We still use char for glyph data in struct fb_image. The type is part
of the kernel uAPI and therefore cannot be changed. Fall back to type
casting in this case.
Destination buffers for font drawing are still u8. This is framebuffer
memory provided by graphics hardware.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/fbdev/core/bitblit.c | 25 ++++++++++++++-----------
drivers/video/fbdev/core/fbcon.h | 4 ++--
drivers/video/fbdev/core/fbcon_ccw.c | 22 ++++++++++++----------
drivers/video/fbdev/core/fbcon_cw.c | 22 ++++++++++++----------
drivers/video/fbdev/core/fbcon_ud.c | 28 +++++++++++++++-------------
5 files changed, 55 insertions(+), 46 deletions(-)
diff --git a/drivers/video/fbdev/core/bitblit.c b/drivers/video/fbdev/core/bitblit.c
index 4838df192ffe..df3fdaf392a6 100644
--- a/drivers/video/fbdev/core/bitblit.c
+++ b/drivers/video/fbdev/core/bitblit.c
@@ -22,12 +22,13 @@
/*
* Accelerated handlers.
*/
-static void update_attr(u8 *dst, const u8 *src, int attribute, struct vc_data *vc)
+static void update_attr(unsigned char *dst, const unsigned char *src, int attribute,
+ struct vc_data *vc)
{
int i, offset = (vc->vc_font.height < 10) ? 1 : 2;
int width = DIV_ROUND_UP(vc->vc_font.width, 8);
unsigned int cellsize = vc->vc_font.height * width;
- u8 c;
+ unsigned char c;
offset = cellsize - (offset * width);
for (i = 0; i < cellsize; i++) {
@@ -75,12 +76,13 @@ static void bit_clear(struct vc_data *vc, struct fb_info *info, int sy,
static inline void bit_putcs_aligned(struct vc_data *vc, struct fb_info *info,
const u16 *s, u32 attr, u32 cnt,
u32 d_pitch, u32 s_pitch, u32 cellsize,
- struct fb_image *image, u8 *buf, u8 *dst)
+ struct fb_image *image,
+ unsigned char *buf, u8 *dst)
{
u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
unsigned int charcnt = vc->vc_font.charcount;
u32 idx = vc->vc_font.width >> 3;
- const u8 *src;
+ const unsigned char *src;
while (cnt--) {
u16 ch = scr_readw(s++) & charmask;
@@ -111,15 +113,15 @@ static inline void bit_putcs_unaligned(struct vc_data *vc,
struct fb_info *info, const u16 *s,
u32 attr, u32 cnt, u32 d_pitch,
u32 s_pitch, u32 cellsize,
- struct fb_image *image, u8 *buf,
- u8 *dst)
+ struct fb_image *image,
+ unsigned char *buf, u8 *dst)
{
u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
unsigned int charcnt = vc->vc_font.charcount;
u32 shift_low = 0, mod = vc->vc_font.width % 8;
u32 shift_high = 8;
u32 idx = vc->vc_font.width >> 3;
- const u8 *src;
+ const unsigned char *src;
while (cnt--) {
u16 ch = scr_readw(s++) & charmask;
@@ -158,7 +160,8 @@ static void bit_putcs(struct vc_data *vc, struct fb_info *info,
u32 buf_align = info->pixmap.buf_align - 1;
u32 mod = vc->vc_font.width % 8, cnt, pitch, size;
u32 attribute = get_attribute(info, scr_readw(s));
- u8 *dst, *buf = NULL;
+ unsigned char *buf = NULL;
+ u8 *dst;
image.fg_color = fg;
image.bg_color = bg;
@@ -249,7 +252,7 @@ static void bit_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
int y = real_y(par->p, vc->state.y);
int attribute, use_sw = vc->vc_cursor_type & CUR_SW;
int err = 1;
- const u8 *src;
+ const unsigned char *src;
cursor.set = 0;
@@ -267,12 +270,12 @@ static void bit_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
if (par->cursor_state.image.data != (const char *)src ||
par->cursor_reset) {
- par->cursor_state.image.data = src;
+ par->cursor_state.image.data = (const char *)src;
cursor.set |= FB_CUR_SETIMAGE;
}
if (attribute) {
- u8 *dst;
+ unsigned char *dst;
dst = kmalloc_array(w, vc->vc_font.height, GFP_ATOMIC);
if (!dst)
diff --git a/drivers/video/fbdev/core/fbcon.h b/drivers/video/fbdev/core/fbcon.h
index 054cf66b15fa..ab78dad15925 100644
--- a/drivers/video/fbdev/core/fbcon.h
+++ b/drivers/video/fbdev/core/fbcon.h
@@ -86,11 +86,11 @@ struct fbcon_par {
int graphics;
bool initialized;
int rotate;
- char *cursor_data;
+ unsigned char *cursor_data;
#ifdef CONFIG_FRAMEBUFFER_CONSOLE_ROTATION
struct {
font_data_t *fontdata; /* source font */
- u8 *buf; /* rotated glyphs */
+ unsigned char *buf; /* rotated glyphs */
size_t bufsize;
int buf_rotate; /* rotation of buf */
} rotated;
diff --git a/drivers/video/fbdev/core/fbcon_ccw.c b/drivers/video/fbdev/core/fbcon_ccw.c
index 9a9839631cc5..de4a58d3385e 100644
--- a/drivers/video/fbdev/core/fbcon_ccw.c
+++ b/drivers/video/fbdev/core/fbcon_ccw.c
@@ -23,13 +23,13 @@
* Rotation 270 degrees
*/
-static void ccw_update_attr(u8 *dst, u8 *src, int attribute,
- struct vc_data *vc)
+static void ccw_update_attr(unsigned char *dst, const unsigned char *src, int attribute,
+ struct vc_data *vc)
{
int i, j, offset = (vc->vc_font.height < 10) ? 1 : 2;
int width = font_glyph_pitch(vc->vc_font.height);
int mod = vc->vc_font.height % 8;
- u8 c, msk = ~(0xff << offset), msk1 = 0;
+ unsigned char c, msk = ~(0xff << offset), msk1 = 0;
if (mod)
msk <<= (8 - mod);
@@ -98,12 +98,13 @@ static void ccw_clear(struct vc_data *vc, struct fb_info *info, int sy,
static inline void ccw_putcs_aligned(struct vc_data *vc, struct fb_info *info,
const u16 *s, u32 attr, u32 cnt,
u32 d_pitch, u32 s_pitch, u32 cellsize,
- struct fb_image *image, u8 *buf, u8 *dst)
+ struct fb_image *image,
+ unsigned char *buf, u8 *dst)
{
struct fbcon_par *par = info->fbcon_par;
u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
u32 idx = font_glyph_pitch(vc->vc_font.height);
- u8 *src;
+ const unsigned char *src;
while (cnt--) {
src = par->rotated.buf + (scr_readw(s--) & charmask) * cellsize;
@@ -139,8 +140,9 @@ static void ccw_putcs(struct vc_data *vc, struct fb_info *info,
u32 buf_align = info->pixmap.buf_align - 1;
u32 cnt, pitch, size;
u32 attribute = get_attribute(info, scr_readw(s));
- u8 *dst, *buf = NULL;
+ unsigned char *buf = NULL;
u32 vyres = GETVYRES(par->p, info);
+ u8 *dst;
if (!par->rotated.buf)
return;
@@ -229,7 +231,7 @@ static void ccw_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
int y = real_y(par->p, vc->state.y);
int attribute, use_sw = vc->vc_cursor_type & CUR_SW;
int err = 1, dx, dy;
- char *src;
+ const unsigned char *src;
u32 vyres = GETVYRES(par->p, info);
if (!par->rotated.buf)
@@ -241,14 +243,14 @@ static void ccw_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
attribute = get_attribute(info, c);
src = par->rotated.buf + ((c & charmask) * (w * vc->vc_font.width));
- if (par->cursor_state.image.data != src ||
+ if (par->cursor_state.image.data != (const char *)src ||
par->cursor_reset) {
- par->cursor_state.image.data = src;
+ par->cursor_state.image.data = (const char *)src;
cursor.set |= FB_CUR_SETIMAGE;
}
if (attribute) {
- u8 *dst;
+ unsigned char *dst;
dst = kmalloc_array(w, vc->vc_font.width, GFP_ATOMIC);
if (!dst)
diff --git a/drivers/video/fbdev/core/fbcon_cw.c b/drivers/video/fbdev/core/fbcon_cw.c
index 4cb20337cf79..4e82199082f1 100644
--- a/drivers/video/fbdev/core/fbcon_cw.c
+++ b/drivers/video/fbdev/core/fbcon_cw.c
@@ -23,12 +23,12 @@
* Rotation 90 degrees
*/
-static void cw_update_attr(u8 *dst, u8 *src, int attribute,
- struct vc_data *vc)
+static void cw_update_attr(unsigned char *dst, const unsigned char *src, int attribute,
+ struct vc_data *vc)
{
int i, j, offset = (vc->vc_font.height < 10) ? 1 : 2;
int width = font_glyph_pitch(vc->vc_font.height);
- u8 c, msk = ~(0xff >> offset);
+ unsigned char c, msk = ~(0xff >> offset);
for (i = 0; i < vc->vc_font.width; i++) {
for (j = 0; j < width; j++) {
@@ -83,12 +83,13 @@ static void cw_clear(struct vc_data *vc, struct fb_info *info, int sy,
static inline void cw_putcs_aligned(struct vc_data *vc, struct fb_info *info,
const u16 *s, u32 attr, u32 cnt,
u32 d_pitch, u32 s_pitch, u32 cellsize,
- struct fb_image *image, u8 *buf, u8 *dst)
+ struct fb_image *image,
+ unsigned char *buf, u8 *dst)
{
struct fbcon_par *par = info->fbcon_par;
u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
u32 idx = font_glyph_pitch(vc->vc_font.height);
- u8 *src;
+ const unsigned char *src;
while (cnt--) {
src = par->rotated.buf + (scr_readw(s++) & charmask) * cellsize;
@@ -124,8 +125,9 @@ static void cw_putcs(struct vc_data *vc, struct fb_info *info,
u32 buf_align = info->pixmap.buf_align - 1;
u32 cnt, pitch, size;
u32 attribute = get_attribute(info, scr_readw(s));
- u8 *dst, *buf = NULL;
+ unsigned char *buf = NULL;
u32 vxres = GETVXRES(par->p, info);
+ u8 *dst;
if (!par->rotated.buf)
return;
@@ -212,7 +214,7 @@ static void cw_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
int y = real_y(par->p, vc->state.y);
int attribute, use_sw = vc->vc_cursor_type & CUR_SW;
int err = 1, dx, dy;
- char *src;
+ const unsigned char *src;
u32 vxres = GETVXRES(par->p, info);
if (!par->rotated.buf)
@@ -224,14 +226,14 @@ static void cw_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
attribute = get_attribute(info, c);
src = par->rotated.buf + ((c & charmask) * (w * vc->vc_font.width));
- if (par->cursor_state.image.data != src ||
+ if (par->cursor_state.image.data != (const char *)src ||
par->cursor_reset) {
- par->cursor_state.image.data = src;
+ par->cursor_state.image.data = (const char *)src;
cursor.set |= FB_CUR_SETIMAGE;
}
if (attribute) {
- u8 *dst;
+ unsigned char *dst;
dst = kmalloc_array(w, vc->vc_font.width, GFP_ATOMIC);
if (!dst)
diff --git a/drivers/video/fbdev/core/fbcon_ud.c b/drivers/video/fbdev/core/fbcon_ud.c
index ac22b9846b79..dc48e19513a1 100644
--- a/drivers/video/fbdev/core/fbcon_ud.c
+++ b/drivers/video/fbdev/core/fbcon_ud.c
@@ -22,13 +22,13 @@
* Rotation 180 degrees
*/
-static void ud_update_attr(u8 *dst, u8 *src, int attribute,
- struct vc_data *vc)
+static void ud_update_attr(unsigned char *dst, const unsigned char *src, int attribute,
+ struct vc_data *vc)
{
int i, offset = (vc->vc_font.height < 10) ? 1 : 2;
int width = font_glyph_pitch(vc->vc_font.width);
unsigned int cellsize = vc->vc_font.height * width;
- u8 c;
+ unsigned char c;
offset = offset * width;
@@ -84,12 +84,13 @@ static void ud_clear(struct vc_data *vc, struct fb_info *info, int sy,
static inline void ud_putcs_aligned(struct vc_data *vc, struct fb_info *info,
const u16 *s, u32 attr, u32 cnt,
u32 d_pitch, u32 s_pitch, u32 cellsize,
- struct fb_image *image, u8 *buf, u8 *dst)
+ struct fb_image *image,
+ unsigned char *buf, u8 *dst)
{
struct fbcon_par *par = info->fbcon_par;
u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
u32 idx = vc->vc_font.width >> 3;
- u8 *src;
+ const unsigned char *src;
while (cnt--) {
src = par->rotated.buf + (scr_readw(s--) & charmask) * cellsize;
@@ -116,15 +117,15 @@ static inline void ud_putcs_unaligned(struct vc_data *vc,
struct fb_info *info, const u16 *s,
u32 attr, u32 cnt, u32 d_pitch,
u32 s_pitch, u32 cellsize,
- struct fb_image *image, u8 *buf,
- u8 *dst)
+ struct fb_image *image,
+ unsigned char *buf, u8 *dst)
{
struct fbcon_par *par = info->fbcon_par;
u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
u32 shift_low = 0, mod = vc->vc_font.width % 8;
u32 shift_high = 8;
u32 idx = vc->vc_font.width >> 3;
- u8 *src;
+ const unsigned char *src;
while (cnt--) {
src = par->rotated.buf + (scr_readw(s--) & charmask) * cellsize;
@@ -160,9 +161,10 @@ static void ud_putcs(struct vc_data *vc, struct fb_info *info,
u32 buf_align = info->pixmap.buf_align - 1;
u32 mod = vc->vc_font.width % 8, cnt, pitch, size;
u32 attribute = get_attribute(info, scr_readw(s));
- u8 *dst, *buf = NULL;
+ unsigned char *buf = NULL;
u32 vyres = GETVYRES(par->p, info);
u32 vxres = GETVXRES(par->p, info);
+ u8 *dst;
if (!par->rotated.buf)
return;
@@ -258,7 +260,7 @@ static void ud_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
int y = real_y(par->p, vc->state.y);
int attribute, use_sw = vc->vc_cursor_type & CUR_SW;
int err = 1, dx, dy;
- char *src;
+ const unsigned char *src;
u32 vyres = GETVYRES(par->p, info);
u32 vxres = GETVXRES(par->p, info);
@@ -271,14 +273,14 @@ static void ud_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
attribute = get_attribute(info, c);
src = par->rotated.buf + ((c & charmask) * (w * vc->vc_font.height));
- if (par->cursor_state.image.data != src ||
+ if (par->cursor_state.image.data != (const char *)src ||
par->cursor_reset) {
- par->cursor_state.image.data = src;
+ par->cursor_state.image.data = (const char *)src;
cursor.set |= FB_CUR_SETIMAGE;
}
if (attribute) {
- u8 *dst;
+ unsigned char *dst;
dst = kmalloc_array(w, vc->vc_font.height, GFP_ATOMIC);
if (!dst)
--
2.56.0
next prev parent reply other threads:[~2026-10-27 13:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-27 13:27 [PATCH 0/6] fbcon: Clean up glyph handling on redraws Thomas Zimmermann
2026-10-27 13:27 ` Thomas Zimmermann [this message]
2026-10-27 13:27 ` [PATCH 2/6] lib/fonts: Provide internal helpers for allocating font_data_t Thomas Zimmermann
2026-10-27 13:27 ` [PATCH 3/6] lib/fonts, fbcon: Use font_data_t for rotated fonts Thomas Zimmermann
2026-10-27 13:27 ` [PATCH 4/6] fbcon: Refactor size calculation for cursor buffers Thomas Zimmermann
2026-10-27 13:27 ` [PATCH 5/6] fbcon: Look up glyphs using the font interface Thomas Zimmermann
2026-10-27 13:27 ` [PATCH 6/6] fbcon: Handle characters with no glyph defined in a consistent way Thomas Zimmermann
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