1 files changed, 387 insertions, 0 deletions
diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
new file mode 100644
index 000000000..f5d533345
--- /dev/null
+++ b/lib/fonts/fonts.c
@@ -0,0 +1,387 @@
+/*
+ * `Soft' font definitions
+ *
+ *    Created 1995 by Geert Uytterhoeven
+ *    Rewritten 1998 by Martin Mares <mj@ucw.cz>
+ *
+ *	2001 - Documented with DocBook
+ *	- Brad Douglas <brad@neruo.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/container_of.h>
+#include <linux/kd.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#if defined(__mc68000__)
+#include <asm/setup.h>
+#endif
+
+#include "font.h"
+
+#define console_font_pitch(font) font_glyph_pitch((font)->width)
+
+/*
+ * Helpers for font_data_t
+ */
+
+/* Extra word getters */
+#define REFCOUNT(fd)	(((int *)(fd))[-1])
+#define FNTSIZE(fd)	(((int *)(fd))[-2])
+#define FNTSUM(fd)	(((int *)(fd))[-4])
+
+static struct font_data *to_font_data_struct(font_data_t *fd)
+{
+	return container_of(fd, struct font_data, data[0]);
+}
+
+static bool font_data_is_internal(font_data_t *fd)
+{
+	return !REFCOUNT(fd); /* internal fonts have no reference counting */
+}
+
+static void font_data_free(font_data_t *fd)
+{
+	kfree(to_font_data_struct(fd));
+}
+
+/**
+ * font_data_import - Allocates and initializes font data from user space
+ * @font: A font from user space
+ * @vpitch: The size of a single glyph in @font in bytes
+ * @calc_csum: An optional helper to calculate a chechsum
+ *
+ * Font data from user space must be translated to the kernel's format. The
+ * font's glyph geometry and data is provided in @font. The parameter @vpitch
+ * gives the number of bytes per glyph, including trailing bytes.
+ *
+ * The parameter @calc_csum is optional. Fbcon passes crc32() to calculate the
+ * font data's checksum.
+ *
+ * Returns:
+ * Newly initialized font data on success, or a pointer-encoded errno value otherwise.
+ */
+font_data_t *font_data_import(const struct console_font *font, unsigned int vpitch,
+			      u32 (*calc_csum)(u32, const void *, size_t))
+{
+	unsigned int pitch = console_font_pitch(font);
+	unsigned int h = font->height;
+	unsigned int charcount = font->charcount;
+	const unsigned char *data = font->data;
+	u32 csum = 0;
+	struct font_data *font_data;
+	int size, alloc_size;
+	unsigned int i;
+	font_data_t *fd;
+
+	/* Check for integer overflow in font-size calculation */
+	if (check_mul_overflow(h, pitch, &size) ||
+	    check_mul_overflow(size, charcount, &size))
+		return ERR_PTR(-EINVAL);
+
+	/* Check for overflow in allocation size calculation */
+	if (check_add_overflow(sizeof(*font_data), size, &alloc_size))
+		return ERR_PTR(-EINVAL);
+
+	font_data = kmalloc(alloc_size, GFP_USER);
+	if (!font_data)
+		return ERR_PTR(-ENOMEM);
+	memset(font_data->extra, 0, sizeof(font_data->extra));
+
+	for (i = 0; i < charcount; ++i)
+		memcpy(font_data->data + i * h * pitch, data + i * vpitch * pitch, h * pitch);
+
+	if (calc_csum)
+		csum = calc_csum(0, font_data->data, size);
+
+	fd = font_data->data;
+	REFCOUNT(fd) = 1; /* start with reference acquired */
+	FNTSIZE(fd) = size;
+	FNTSUM(fd) = csum;
+
+	return fd;
+}
+EXPORT_SYMBOL_GPL(font_data_import);
+
+/**
+ * font_data_get - Acquires a reference on font data
+ * @fd: Font data
+ *
+ * Font data from user space is reference counted. The helper
+ * font_data_get() increases the reference counter by one. Invoke
+ * font_data_put() to release the reference.
+ *
+ * Internal font data is located in read-only memory. In this case
+ * the helper returns success without modifying the counter field.
+ * It is still required to call font_data_put() on internal font data.
+ */
+void font_data_get(font_data_t *fd)
+{
+	if (font_data_is_internal(fd))
+		return; /* never ref static data */
+
+	if (WARN_ON(!REFCOUNT(fd)))
+		return; /* should never be 0 */
+	++REFCOUNT(fd);
+}
+EXPORT_SYMBOL_GPL(font_data_get);
+
+/**
+ * font_data_put - Release a reference on font data
+ * @fd: Font data
+ *
+ * Font data from user space is reference counted. The helper
+ * font_data_put() decreases the reference counter by one. If this was
+ * the final reference, it frees the allocated memory.
+ *
+ * Internal font data is located in read-only memory. In this case
+ * the helper returns success without modifying the counter field.
+ *
+ * Returns:
+ * True if the font data's memory buffer has been freed, false otherwise.
+ */
+bool font_data_put(font_data_t *fd)
+{
+	unsigned int count;
+
+	if (font_data_is_internal(fd))
+		return false; /* never unref static data */
+
+	if (WARN_ON(!REFCOUNT(fd)))
+		return false; /* should never be 0 */
+
+	count = --REFCOUNT(fd);
+	if (!count)
+		font_data_free(fd);
+
+	return !count;
+}
+EXPORT_SYMBOL_GPL(font_data_put);
+
+/**
+ * font_data_size - Return size of the font data in bytes
+ * @fd: Font data
+ *
+ * Returns:
+ * The number of bytes in the given font data.
+ */
+unsigned int font_data_size(font_data_t *fd)
+{
+	return FNTSIZE(fd);
+}
+EXPORT_SYMBOL_GPL(font_data_size);
+
+/**
+ * font_data_is_equal - Compares font data for equality
+ * @lhs: Left-hand side font data
+ * @rhs: Right-hand-size font data
+ *
+ * Font data is equal if is constain the same sequence of values. The
+ * helper also use the checksum, if both arguments contain it. Font data
+ * coming from different origins, internal or from user space, is never
+ * equal. Allowing this would break reference counting.
+ *
+ * Returns:
+ * True if the given font data is equal, false otherwise.
+ */
+bool font_data_is_equal(font_data_t *lhs, font_data_t *rhs)
+{
+	if (font_data_is_internal(lhs) != font_data_is_internal(rhs))
+		return false;
+	if (font_data_size(lhs) != font_data_size(rhs))
+		return false;
+	if (FNTSUM(lhs) && FNTSUM(rhs) && FNTSUM(lhs) != FNTSUM(rhs))
+		return false;
+
+	return !memcmp(lhs, rhs, FNTSIZE(lhs));
+}
+EXPORT_SYMBOL_GPL(font_data_is_equal);
+
+/**
+ * font_data_export - Stores font data for user space
+ * @fd: Font data
+ * @font: A font for user space
+ * @vpitch: The size of a single glyph in @font in bytes
+ *
+ * Store the font data given in @fd to the font in @font. Values and
+ * pointers in @font are pre-initialized. This helper mostly checks some
+ * corner cases and translates glyph sizes according to the value given
+ * @vpitch.
+ *
+ * Returns:
+ * 0 on success, or a negative errno code otherwise.
+ */
+int font_data_export(font_data_t *fd, struct console_font *font, unsigned int vpitch)
+{
+	const unsigned char *font_data = font_data_buf(fd);
+	unsigned char *data = font->data;
+	unsigned int pitch = console_font_pitch(font);
+	unsigned int glyphsize, i;
+
+	if (!font->width || !font->height || !font->charcount || !font->data)
+		return 0;
+
+	glyphsize = font->height * pitch;
+
+	if (font->charcount * glyphsize > font_data_size(fd))
+		return -EINVAL;
+
+	for (i = 0; i < font->charcount; i++) {
+		memcpy(data, font_data, glyphsize);
+		memset(data + glyphsize, 0, pitch * vpitch - glyphsize);
+		data += pitch * vpitch;
+		font_data += glyphsize;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(font_data_export);
+
+/*
+ * Font lookup
+ */
+
+static const struct font_desc *fonts[] = {
+#ifdef CONFIG_FONT_8x8
+	&font_vga_8x8,
+#endif
+#ifdef CONFIG_FONT_8x16
+	&font_vga_8x16,
+#endif
+#ifdef CONFIG_FONT_6x11
+	&font_vga_6x11,
+#endif
+#ifdef CONFIG_FONT_7x14
+	&font_7x14,
+#endif
+#ifdef CONFIG_FONT_SUN8x16
+	&font_sun_8x16,
+#endif
+#ifdef CONFIG_FONT_SUN12x22
+	&font_sun_12x22,
+#endif
+#ifdef CONFIG_FONT_10x18
+	&font_10x18,
+#endif
+#ifdef CONFIG_FONT_ACORN_8x8
+	&font_acorn_8x8,
+#endif
+#ifdef CONFIG_FONT_PEARL_8x8
+	&font_pearl_8x8,
+#endif
+#ifdef CONFIG_FONT_MINI_4x6
+	&font_mini_4x6,
+#endif
+#ifdef CONFIG_FONT_6x10
+	&font_6x10,
+#endif
+#ifdef CONFIG_FONT_TER10x18
+	&font_ter_10x18,
+#endif
+#ifdef CONFIG_FONT_TER16x32
+	&font_ter_16x32,
+#endif
+#ifdef CONFIG_FONT_6x8
+	&font_6x8,
+#endif
+};
+
+#define num_fonts ARRAY_SIZE(fonts)
+
+#ifdef NO_FONTS
+#error No fonts configured.
+#endif
+
+
+/**
+ *	find_font - find a font
+ *	@name: string name of a font
+ *
+ *	Find a specified font with string name @name.
+ *
+ *	Returns %NULL if no font found, or a pointer to the
+ *	specified font.
+ *
+ */
+const struct font_desc *find_font(const char *name)
+{
+	unsigned int i;
+
+	BUILD_BUG_ON(!num_fonts);
+	for (i = 0; i < num_fonts; i++)
+		if (!strcmp(fonts[i]->name, name))
+			return fonts[i];
+	return NULL;
+}
+EXPORT_SYMBOL(find_font);
+
+
+/**
+ *	get_default_font - get default font
+ *	@xres: screen size of X
+ *	@yres: screen size of Y
+ *	@font_w: bit array of supported widths (1 - FB_MAX_BLIT_WIDTH)
+ *	@font_h: bit array of supported heights (1 - FB_MAX_BLIT_HEIGHT)
+ *
+ *	Get the default font for a specified screen size.
+ *	Dimensions are in pixels.
+ *
+ *	font_w or font_h being NULL means all values are supported.
+ *
+ *	Returns %NULL if no font is found, or a pointer to the
+ *	chosen font.
+ *
+ */
+const struct font_desc *get_default_font(int xres, int yres,
+					 unsigned long *font_w,
+					 unsigned long *font_h)
+{
+	int i, c, cc, res;
+	const struct font_desc *f, *g;
+
+	g = NULL;
+	cc = -10000;
+	for (i = 0; i < num_fonts; i++) {
+		f = fonts[i];
+		c = f->pref;
+#if defined(__mc68000__)
+#ifdef CONFIG_FONT_PEARL_8x8
+		if (MACH_IS_AMIGA && f->idx == PEARL8x8_IDX)
+			c = 100;
+#endif
+#ifdef CONFIG_FONT_6x11
+		if (MACH_IS_MAC && xres < 640 && f->idx == VGA6x11_IDX)
+			c = 100;
+#endif
+#endif
+		if ((yres < 400) == (f->height <= 8))
+			c += 1000;
+
+		/* prefer a bigger font for high resolution */
+		res = (xres / f->width) * (yres / f->height) / 1000;
+		if (res > 20)
+			c += 20 - res;
+
+		if ((!font_w || test_bit(f->width - 1, font_w)) &&
+		    (!font_h || test_bit(f->height - 1, font_h)))
+			c += 1000;
+
+		if (c > cc) {
+			cc = c;
+			g = f;
+		}
+	}
+	return g;
+}
+EXPORT_SYMBOL(get_default_font);
+
+MODULE_AUTHOR("James Simmons <jsimmons@users.sf.net>");
+MODULE_DESCRIPTION("Console Fonts");
+MODULE_LICENSE("GPL");