tty/vt: consolemap: introduce UNI_*() macros

The code currently does shift, OR, and AND logic directly in the code.
It is not much obvious what happens there. Therefore define four macros
for that purpose and use them in the code. We use GENMASK() so that it
is clear which bits serve what purpose:
- UNI_GLYPH: bits  0.. 5
- UNI_ROW:   bits  6..10
- UNI_DIR:   bits 11..31

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-10-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index 016c1a0b429077b0d7fe50ca575b2a421456fa67..e5fd225e87bda2c701f6a60073e5cce224b4f0f7 100644 (file)
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -190,6 +190,11 @@ static int inv_translate[MAX_NR_CONSOLES];
 #define UNI_DIR_ROWS   32U
 #define UNI_ROW_GLYPHS 64U
 
+#define UNI_DIR(uni)           ( (uni)                   >> 11)
+#define UNI_ROW(uni)           (((uni) & GENMASK(10, 6)) >>  6)
+#define UNI_GLYPH(uni)         ( (uni) & GENMASK( 5, 0))
+#define UNI(dir, row, glyph)   (((dir) << 11) | ((row) << 6) | (glyph))
+
 /**
  * struct uni_pagedict -- unicode directory
  *
@@ -265,7 +270,7 @@ static void set_inverse_trans_unicode(struct vc_data *conp,
                                glyph = p2[k];
                                if (glyph >= 0 && glyph < MAX_GLYPH
                                               && q[glyph] < 32)
-                                       q[glyph] = (i << 11) | (j << 6) | k;
+                                       q[glyph] = UNI(i, j, k);
                        }
                }
        }
@@ -497,7 +502,7 @@ con_insert_unipair(struct uni_pagedict *p, u_short unicode, u_short fontpos)
        int i, n;
        u16 **p1, *p2;
 
-       n = unicode >> 11;
+       n = UNI_DIR(unicode);
        p1 = p->uni_pgdir[n];
        if (!p1) {
                p1 = p->uni_pgdir[n] = kmalloc_array(UNI_DIR_ROWS,
@@ -508,7 +513,7 @@ con_insert_unipair(struct uni_pagedict *p, u_short unicode, u_short fontpos)
                        p1[i] = NULL;
        }
 
-       n = (unicode >> 6) & 0x1f;
+       n = UNI_ROW(unicode);
        p2 = p1[n];
        if (!p2) {
                p2 = p1[n] = kmalloc_array(UNI_ROW_GLYPHS, sizeof(u16), GFP_KERNEL);
@@ -518,7 +523,7 @@ con_insert_unipair(struct uni_pagedict *p, u_short unicode, u_short fontpos)
                memset(p2, 0xff, UNI_ROW_GLYPHS * sizeof(u16));
        }
 
-       p2[unicode & 0x3f] = fontpos;
+       p2[UNI_GLYPH(unicode)] = fontpos;
        
        p->sum += (fontpos << 20U) + unicode;
 
@@ -788,7 +793,7 @@ int con_get_unimap(struct vc_data *vc, ushort ct, ushort __user *uct, struct uni
                                                continue;
                                        if (ect < ct) {
                                                unilist[ect].unicode =
-                                                       (i<<11) | (j<<6) | k;
+                                                       UNI(i, j, k);
                                                unilist[ect].fontpos = *p2;
                                        }
                                        ect++;
@@ -857,9 +862,9 @@ conv_uni_to_pc(struct vc_data *conp, long ucs)
                return -3;
 
        p = *conp->vc_uni_pagedir_loc;
-       if ((p1 = p->uni_pgdir[ucs >> 11]) &&
-           (p2 = p1[(ucs >> 6) & 0x1f]) &&
-           (h = p2[ucs & 0x3f]) < MAX_GLYPH)
+       if ((p1 = p->uni_pgdir[UNI_DIR(ucs)]) &&
+           (p2 = p1[UNI_ROW(ucs)]) &&
+           (h = p2[UNI_GLYPH(ucs)]) < MAX_GLYPH)
                return h;
 
        return -4;              /* not found */