unicode diacritics support

There have been issues with non-latin1 diacritics and unicode.
http://bugzilla.kernel.org/show_bug.cgi?id=7746

Git 759448f459234bfcf34b82471f0dba77a9aca498 `Kernel utf-8 handling'
partly resolved it by adding conversion between diacritics and
unicode. The patch below goes further by just turning diacritics into
unicode, hence providing better future support. The kbd support can be
fetched from
http://bugzilla.kernel.org/attachment.cgi?id=12313

This was tested in all of latin1, latin9, latin2 and unicode with french
and czech dead keys.

Turn the kernel accent_table into unicode, and extend ioctls KDGKBDIACR
and KDSKBDIACR into their equivalents KDGKBDIACRUC and KDSKBDIACR.

New function int conv_uni_to_8bit(u32 uni) for converting unicode into 8bit
_input_.  No, we don't want to store the translation, as it is potentially
sparse and large.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Jan Engelhardt <jengelh@gmx.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/consolemap.c b/drivers/char/consolemap.c
index 163f3fc..6b104e4 100644
--- a/drivers/char/consolemap.c
+++ b/drivers/char/consolemap.c
@@ -669,19 +669,29 @@
 		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)
 {
-	/*
-	 * Always use USER_MAP. This function is 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.
-	 */
 	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) 
 {
diff --git a/drivers/char/defkeymap.c_shipped b/drivers/char/defkeymap.c_shipped
index 453a2f1..0aa419a 100644
--- a/drivers/char/defkeymap.c_shipped
+++ b/drivers/char/defkeymap.c_shipped
@@ -222,7 +222,7 @@
 	NULL,
 };
 
-struct kbdiacr accent_table[MAX_DIACR] = {
+struct kbdiacruc accent_table[MAX_DIACR] = {
 	{'`', 'A', '\300'},	{'`', 'a', '\340'},
 	{'\'', 'A', '\301'},	{'\'', 'a', '\341'},
 	{'^', 'A', '\302'},	{'^', 'a', '\342'},
diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index d95f316..5ae2a32 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -38,6 +38,7 @@
 #include <linux/kbd_kern.h>
 #include <linux/kbd_diacr.h>
 #include <linux/vt_kern.h>
+#include <linux/consolemap.h>
 #include <linux/sysrq.h>
 #include <linux/input.h>
 #include <linux/reboot.h>
@@ -403,9 +404,12 @@
 		return d;
 
 	if (kbd->kbdmode == VC_UNICODE)
-		to_utf8(vc, conv_8bit_to_uni(d));
-	else if (d < 0x100)
-		put_queue(vc, d);
+		to_utf8(vc, d);
+	else {
+		int c = conv_uni_to_8bit(d);
+		if (c != -1)
+			put_queue(vc, c);
+	}
 
 	return ch;
 }
@@ -417,9 +421,12 @@
 {
 	if (diacr) {
 		if (kbd->kbdmode == VC_UNICODE)
-			to_utf8(vc, conv_8bit_to_uni(diacr));
-		else if (diacr < 0x100)
-			put_queue(vc, diacr);
+			to_utf8(vc, diacr);
+		else {
+			int c = conv_uni_to_8bit(diacr);
+			if (c != -1)
+				put_queue(vc, c);
+		}
 		diacr = 0;
 	}
 	put_queue(vc, 13);
@@ -627,9 +634,12 @@
 		return;
 	}
 	if (kbd->kbdmode == VC_UNICODE)
-		to_utf8(vc, conv_8bit_to_uni(value));
-	else if (value < 0x100)
-		put_queue(vc, value);
+		to_utf8(vc, value);
+	else {
+		int c = conv_uni_to_8bit(value);
+		if (c != -1)
+			put_queue(vc, c);
+	}
 }
 
 /*
@@ -646,7 +656,12 @@
 
 static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
 {
-	k_unicode(vc, value, up_flag);
+	unsigned int uni;
+	if (kbd->kbdmode == VC_UNICODE)
+		uni = value;
+	else
+		uni = conv_8bit_to_uni(value);
+	k_unicode(vc, uni, up_flag);
 }
 
 static void k_dead2(struct vc_data *vc, unsigned char value, char up_flag)
diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index f69a825..6c7384a 100644
--- a/drivers/char/vt_ioctl.c
+++ b/drivers/char/vt_ioctl.c
@@ -23,6 +23,7 @@
 #include <linux/major.h>
 #include <linux/fs.h>
 #include <linux/console.h>
+#include <linux/consolemap.h>
 #include <linux/signal.h>
 #include <linux/timex.h>
 
@@ -582,10 +583,27 @@
 	case KDGKBDIACR:
 	{
 		struct kbdiacrs __user *a = up;
+		struct kbdiacr diacr;
+		int i;
 
 		if (put_user(accent_table_size, &a->kb_cnt))
 			return -EFAULT;
-		if (copy_to_user(a->kbdiacr, accent_table, accent_table_size*sizeof(struct kbdiacr)))
+		for (i = 0; i < accent_table_size; i++) {
+			diacr.diacr = conv_uni_to_8bit(accent_table[i].diacr);
+			diacr.base = conv_uni_to_8bit(accent_table[i].base);
+			diacr.result = conv_uni_to_8bit(accent_table[i].result);
+			if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
+				return -EFAULT;
+		}
+		return 0;
+	}
+	case KDGKBDIACRUC:
+	{
+		struct kbdiacrsuc __user *a = up;
+
+		if (put_user(accent_table_size, &a->kb_cnt))
+			return -EFAULT;
+		if (copy_to_user(a->kbdiacruc, accent_table, accent_table_size*sizeof(struct kbdiacruc)))
 			return -EFAULT;
 		return 0;
 	}
@@ -593,6 +611,30 @@
 	case KDSKBDIACR:
 	{
 		struct kbdiacrs __user *a = up;
+		struct kbdiacr diacr;
+		unsigned int ct;
+		int i;
+
+		if (!perm)
+			return -EPERM;
+		if (get_user(ct,&a->kb_cnt))
+			return -EFAULT;
+		if (ct >= MAX_DIACR)
+			return -EINVAL;
+		accent_table_size = ct;
+		for (i = 0; i < ct; i++) {
+			if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
+				return -EFAULT;
+			accent_table[i].diacr = conv_8bit_to_uni(diacr.diacr);
+			accent_table[i].base = conv_8bit_to_uni(diacr.base);
+			accent_table[i].result = conv_8bit_to_uni(diacr.result);
+		}
+		return 0;
+	}
+
+	case KDSKBDIACRUC:
+	{
+		struct kbdiacrsuc __user *a = up;
 		unsigned int ct;
 
 		if (!perm)
@@ -602,7 +644,7 @@
 		if (ct >= MAX_DIACR)
 			return -EINVAL;
 		accent_table_size = ct;
-		if (copy_from_user(accent_table, a->kbdiacr, ct*sizeof(struct kbdiacr)))
+		if (copy_from_user(accent_table, a->kbdiacruc, ct*sizeof(struct kbdiacruc)))
 			return -EFAULT;
 		return 0;
 	}