linux.git/drivers/video/fbdev/core/fbcon.c, branch v7.1

fbcon: Put font-rotation state into separate struct

2026-04-07T15:38:07+00:00

Move all temporary state of the font-rotation code into the struct
rotated in struct fbcon_par. Protect it with the Kconfig symbol
CONFIG_FRAMEBUFFER_CONSOLE_ROTATION. Avoids mixing it up with fbcon's
regular state.

v2:
- fix typos

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

fbcon: Fill cursor mask in helper function

2026-04-07T15:38:07+00:00

Fbcon creates a cursor shape on the fly from the user-configured
settings. The logic to create a glyph with the cursor's bitmap mask
is duplicated in four places. In the cases that involve console
rotation, the implementation further rotates the cursor glyph for
displaying.

Consolidate all cursor-mask creation in a single helper. Update the
callers accordingly. For console rotation, use the glyph helpers to
rotate the created cursor glyph to the correct orientation.

v2:
- fix sparse truncated-bits warning

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

lib/fonts: Store font data for user space with font_data_export()

2026-03-09T14:47:21+00:00

Add font_data_export() and update consoles to use it.

The helper font_data_export() is based on code in fbcon_get_font().
It extends the size of a single glyph to match the requested vpitch,
which us usually 32 bytes for fonts from user space. Internal fonts
have a pitch according to the glyph's height.

The implementation of font_data_export() differs in several ways from
the original code. The original implementation distinguished between
different pitches of the font data. This is not necessary as the pitch
is a parameter in the copying.

There was also special handling for a font pitch of 3 bytes, which got
expanded to 4 bytes (with trailing bits on each scanline). The logic
originated from long before git history exists even in the historical
tree. So it is not clear why this was implemented. It is not what user
space expects. The setfont utitlity loads font with 3-bytes pitches and
expects to read such fonts with a 3-byte pitch. For any font width, the
font pitch is always the width extended to the next multiple of 8. See
[1] for the user-space font-reading code.

With the changes to handling the font pitches, font_data_export() replaces
the original code's various special cases with a single copying logic.

v3:
- fix typos (Helge)

Signed-off-by: Thomas Zimmermann 
Link: https://github.com/legionus/kbd/blob/v2.9.0/src/libkfont/kdfontop.c#L73 # [1]
Signed-off-by: Helge Deller

lib/fonts: Create font_data_t from struct console_font with font_data_import()

2026-03-09T14:47:21+00:00

Add font_data_import() and update consoles to use it.

The implementation of font_data_import() is based on code from fbcon,
which supports overflow checks and crc32 checksums. Fbcon uses the crc32
checksum.

Newport_con now implements the same overflow checks as fbcon. As before,
this console does not support checksums, which are optional. Newport_con
can now also handle input font data with a vertical pitch other than 32
bytes. (The vertical pitch is the offset between two glyphs in the font
data.)

As an internal change, remove the const qualifier from the data field
if struct font_data. This allows font_data_import() to write the data
without type casting. For all users of the font data via font_data_t,
the stored data is still read only.

v3:
- fix typos

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

lib/fonts: Compare font data for equality with font_data_is_equal()

2026-03-09T14:47:21+00:00

Add font_data_is_equal() and update consoles to use it.

Font data is equal if it has the same size and contains the same values
on all bytes. Only fbcon uses a crc32 checksum. If set in both operands
the checksums have to be equal.

The new helper also guarantees to not compare internal fonts against
fonts from user space. Internal fonts cannot be ref-counted, so making
them equal to user-space fonts with the same byte sequence results in
undefined behavior.

The test only compares data buffers. Their interpretation is up each
console. Therefore remove a width test in fbcon_set_font().

v3:
- rebase onto font_data_{get,put}()

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

lib/fonts: Manage font-data lifetime with font_data_get/_put()

2026-03-09T14:47:21+00:00

Add font_data_get() and font_data_put(). Update consoles to use them
over REFCOUNT() and plain kfree().

Newly allocated font data starts with a reference count of 1. Loading
the font puts the previously loaded font. If the reference count reaches
zero, font_data_put() frees the font data.

The kernel stores a refcount of zero for internal font data. Invoking
font_data_get() and font_data_put() tests this internally and returns
success without further operation. From the caller's perspective,
getting and putting works the same for all font data.

Fbcon used the userfont flag distinguish between internal fonts and
fonts loaded by user space. Only the latter where refcounted. With the
new helper's automatic handling of internal font data, remove the
userfont flag from fbcon.

Newport_con uses a default font, FONT_DATA, until user space loads
custom font data. Remove all special cases for FONT_DATA, as the get
and put calls' read-only handling also covers this case.

v3:
- fix module linker error wrt font symbols (Nathan, Arnd)
- fix typos

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

lib/fonts: Read font size with font_data_size()

2026-03-09T14:47:20+00:00

Add font_data_size() and update consoles to use it.

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

lib/fonts: Store font data as font_data_t; update consoles

2026-03-09T14:47:20+00:00

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.

v3:
- fix typos (Helge)
v2:
- 'Font lookup' -> 'Font description' in 

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

vt: Calculate font-buffer size with vc_font_size()

2026-03-09T14:47:20+00:00

In fbcon, fbcon_resize() computes the size of the font buffer from the
values stored in vc_font. Move these calculations to the dedicated helpers
vc_font_pitch() and vc_font_size().

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

vt: Store font in struct vc_font

2026-03-09T14:47:20+00:00

Replace struct console_font with struct vc_font for the type of the
vc_font field of struct vc_data. Struct console_font is UAPI, which
prevents further changes. Hence a new data type is required.

Struct console_font has a documented vertical pitch of 32 bytes. This
is not the case after the font data has been loaded into the kernel.
Changing the type of vc_font addresses this inconsistency.

The font data is now declared as constant, as it might come from the
kernel's read-only section. There's some fallout throughout the console
code where non-const variables refer to it. Fix them. A later update
will declare the font data to a dedicated data type.

v3:
- fix typos

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller