consolemap.c

linux 内核源代码

 *
 * A font has at most 512 chars, usually 256.
 * But one font position may represent several Unicode chars.
 * A hashtable is somewhat of a pain to deal with, so use a
 * "paged table" instead.  Simulation has shown the memory cost of
 * this 3-level paged table scheme to be comparable to a hash table.
 */

extern u8 dfont_unicount[];	/* Defined in console_defmap.c */
extern u16 dfont_unitable[];

static void con_release_unimap(struct uni_pagedir *p)
{
	u16 **p1;
	int i, j;

	if (p == dflt) dflt = NULL;  
	for (i = 0; i < 32; i++) {
		if ((p1 = p->uni_pgdir[i]) != NULL) {
			for (j = 0; j < 32; j++)
				kfree(p1[j]);
			kfree(p1);
		}
		p->uni_pgdir[i] = NULL;
	}
	for (i = 0; i < 4; i++) {
		kfree(p->inverse_translations[i]);
		p->inverse_translations[i] = NULL;
	}
	if (p->inverse_trans_unicode) {
		kfree(p->inverse_trans_unicode);
		p->inverse_trans_unicode = NULL;
	}
}

void con_free_unimap(struct vc_data *vc)
{
	struct uni_pagedir *p;

	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
	if (!p)
		return;
	*vc->vc_uni_pagedir_loc = 0;
	if (--p->refcount)
		return;
	con_release_unimap(p);
	kfree(p);
}
  
static int con_unify_unimap(struct vc_data *conp, struct uni_pagedir *p)
{
	int i, j, k;
	struct uni_pagedir *q;
	
	for (i = 0; i < MAX_NR_CONSOLES; i++) {
		if (!vc_cons_allocated(i))
			continue;
		q = (struct uni_pagedir *)*vc_cons[i].d->vc_uni_pagedir_loc;
		if (!q || q == p || q->sum != p->sum)
			continue;
		for (j = 0; j < 32; j++) {
			u16 **p1, **q1;
			p1 = p->uni_pgdir[j]; q1 = q->uni_pgdir[j];
			if (!p1 && !q1)
				continue;
			if (!p1 || !q1)
				break;
			for (k = 0; k < 32; k++) {
				if (!p1[k] && !q1[k])
					continue;
				if (!p1[k] || !q1[k])
					break;
				if (memcmp(p1[k], q1[k], 64*sizeof(u16)))
					break;
			}
			if (k < 32)
				break;
		}
		if (j == 32) {
			q->refcount++;
			*conp->vc_uni_pagedir_loc = (unsigned long)q;
			con_release_unimap(p);
			kfree(p);
			return 1;
		}
	}
	return 0;
}

static int
con_insert_unipair(struct uni_pagedir *p, u_short unicode, u_short fontpos)
{
	int i, n;
	u16 **p1, *p2;

	if (!(p1 = p->uni_pgdir[n = unicode >> 11])) {
		p1 = p->uni_pgdir[n] = kmalloc(32*sizeof(u16 *), GFP_KERNEL);
		if (!p1) return -ENOMEM;
		for (i = 0; i < 32; i++)
			p1[i] = NULL;
	}

	if (!(p2 = p1[n = (unicode >> 6) & 0x1f])) {
		p2 = p1[n] = kmalloc(64*sizeof(u16), GFP_KERNEL);
		if (!p2) return -ENOMEM;
		memset(p2, 0xff, 64*sizeof(u16)); /* No glyphs for the characters (yet) */
	}

	p2[unicode & 0x3f] = fontpos;
	
	p->sum += (fontpos << 20) + unicode;

	return 0;
}

/* ui is a leftover from using a hashtable, but might be used again */
int con_clear_unimap(struct vc_data *vc, struct unimapinit *ui)
{
	struct uni_pagedir *p, *q;
  
	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
	if (p && p->readonly) return -EIO;
	if (!p || --p->refcount) {
		q = kzalloc(sizeof(*p), GFP_KERNEL);
		if (!q) {
			if (p) p->refcount++;
			return -ENOMEM;
		}
		q->refcount=1;
		*vc->vc_uni_pagedir_loc = (unsigned long)q;
	} else {
		if (p == dflt) dflt = NULL;
		p->refcount++;
		p->sum = 0;
		con_release_unimap(p);
	}
	return 0;
}

int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
{
	int err = 0, err1, i;
	struct uni_pagedir *p, *q;

	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
	if (p->readonly) return -EIO;
	
	if (!ct) return 0;
	
	if (p->refcount > 1) {
		int j, k;
		u16 **p1, *p2, l;
		
		err1 = con_clear_unimap(vc, NULL);
		if (err1) return err1;
		
		q = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
		for (i = 0, l = 0; i < 32; i++)
		if ((p1 = p->uni_pgdir[i]))
			for (j = 0; j < 32; j++)
			if ((p2 = p1[j]))
				for (k = 0; k < 64; k++, l++)
				if (p2[k] != 0xffff) {
					err1 = con_insert_unipair(q, l, p2[k]);
					if (err1) {
						p->refcount++;
						*vc->vc_uni_pagedir_loc = (unsigned long)p;
						con_release_unimap(q);
						kfree(q);
						return err1; 
					}
              			}
              	p = q;
	} else if (p == dflt)
		dflt = NULL;
	
	while (ct--) {
		unsigned short unicode, fontpos;
		__get_user(unicode, &list->unicode);
		__get_user(fontpos, &list->fontpos);
		if ((err1 = con_insert_unipair(p, unicode,fontpos)) != 0)
			err = err1;
			list++;
	}
	
	if (con_unify_unimap(vc, p))
		return err;

	for (i = 0; i <= 3; i++)
		set_inverse_transl(vc, p, i); /* Update all inverse translations */
	set_inverse_trans_unicode(vc, p);
  
	return err;
}

/* Loads the unimap for the hardware font, as defined in uni_hash.tbl.
   The representation used was the most compact I could come up
   with.  This routine is executed at sys_setup time, and when the
   PIO_FONTRESET ioctl is called. */

int con_set_default_unimap(struct vc_data *vc)
{
	int i, j, err = 0, err1;
	u16 *q;
	struct uni_pagedir *p;

	if (dflt) {
		p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
		if (p == dflt)
			return 0;
		dflt->refcount++;
		*vc->vc_uni_pagedir_loc = (unsigned long)dflt;
		if (p && --p->refcount) {
			con_release_unimap(p);
			kfree(p);
		}
		return 0;
	}
	
	/* The default font is always 256 characters */

	err = con_clear_unimap(vc, NULL);
	if (err) return err;
    
	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
	q = dfont_unitable;
	
	for (i = 0; i < 256; i++)
		for (j = dfont_unicount[i]; j; j--) {
			err1 = con_insert_unipair(p, *(q++), i);
			if (err1)
				err = err1;
		}
			
	if (con_unify_unimap(vc, p)) {
		dflt = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
		return err;
	}

	for (i = 0; i <= 3; i++)
		set_inverse_transl(vc, p, i);	/* Update all inverse translations */
	set_inverse_trans_unicode(vc, p);
	dflt = p;
	return err;
}
EXPORT_SYMBOL(con_set_default_unimap);

int con_copy_unimap(struct vc_data *dst_vc, struct vc_data *src_vc)
{
	struct uni_pagedir *q;

	if (!*src_vc->vc_uni_pagedir_loc)
		return -EINVAL;
	if (*dst_vc->vc_uni_pagedir_loc == *src_vc->vc_uni_pagedir_loc)
		return 0;
	con_free_unimap(dst_vc);
	q = (struct uni_pagedir *)*src_vc->vc_uni_pagedir_loc;
	q->refcount++;
	*dst_vc->vc_uni_pagedir_loc = (long)q;
	return 0;
}

int con_get_unimap(struct vc_data *vc, ushort ct, ushort __user *uct, struct unipair __user *list)
{
	int i, j, k, ect;
	u16 **p1, *p2;
	struct uni_pagedir *p;

	ect = 0;
	if (*vc->vc_uni_pagedir_loc) {
		p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
		for (i = 0; i < 32; i++)
		if ((p1 = p->uni_pgdir[i]))
			for (j = 0; j < 32; j++)
			if ((p2 = *(p1++)))
				for (k = 0; k < 64; k++) {
					if (*p2 < MAX_GLYPH && ect++ < ct) {
						__put_user((u_short)((i<<11)+(j<<6)+k),
							   &list->unicode);
						__put_user((u_short) *p2, 
							   &list->fontpos);
						list++;
					}
					p2++;
				}
	}
	__put_user(ect, uct);
	return ((ect <= ct) ? 0 : -ENOMEM);
}

void con_protect_unimap(struct vc_data *vc, int rdonly)
{
	struct uni_pagedir *p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
	
	if (p)
		p->readonly = rdonly;
}

/*
 * Always use USER_MAP. These functions are used by the keyboard,
 * which shouldn't be affected by G0/G1 switching, etc.
 * If the user map still contains default values, i.e. the
 * direct-to-font mapping, then assume user is using Latin1.
 */
/* may be called during an interrupt */
u32 conv_8bit_to_uni(unsigned char c)
{
	unsigned short uni = translations[USER_MAP][c];
	return uni == (0xf000 | c) ? c : uni;
}

int conv_uni_to_8bit(u32 uni)
{
	int c;
	for (c = 0; c < 0x100; c++)
		if (translations[USER_MAP][c] == uni ||
		   (translations[USER_MAP][c] == (c | 0xf000) && uni == c))
			return c;
	return -1;
}

int
conv_uni_to_pc(struct vc_data *conp, long ucs) 
{
	int h;
	u16 **p1, *p2;
	struct uni_pagedir *p;
  
	/* Only 16-bit codes supported at this time */
	if (ucs > 0xffff)
		return -4;		/* Not found */
	else if (ucs < 0x20)
		return -1;		/* Not a printable character */
	else if (ucs == 0xfeff || (ucs >= 0x200b && ucs <= 0x200f))
		return -2;			/* Zero-width space */
	/*
	 * UNI_DIRECT_BASE indicates the start of the region in the User Zone
	 * which always has a 1:1 mapping to the currently loaded font.  The
	 * UNI_DIRECT_MASK indicates the bit span of the region.
	 */
	else if ((ucs & ~UNI_DIRECT_MASK) == UNI_DIRECT_BASE)
		return ucs & UNI_DIRECT_MASK;
  
	if (!*conp->vc_uni_pagedir_loc)
		return -3;

	p = (struct uni_pagedir *)*conp->vc_uni_pagedir_loc;  
	if ((p1 = p->uni_pgdir[ucs >> 11]) &&
	    (p2 = p1[(ucs >> 6) & 0x1f]) &&
	    (h = p2[ucs & 0x3f]) < MAX_GLYPH)
		return h;

	return -4;		/* not found */
}

/*
 * This is called at sys_setup time, after memory and the console are
 * initialized.  It must be possible to call kmalloc(..., GFP_KERNEL)
 * from this function, hence the call from sys_setup.
 */
void __init 
console_map_init(void)
{
	int i;
	
	for (i = 0; i < MAX_NR_CONSOLES; i++)
		if (vc_cons_allocated(i) && !*vc_cons[i].d->vc_uni_pagedir_loc)
			con_set_default_unimap(vc_cons[i].d);
}

EXPORT_SYMBOL(con_copy_unimap);