drivers/staging/speakup/selection.c

   1 #include <linux/slab.h> /* for kmalloc */
   2 #include <linux/consolemap.h>
   3 #include <linux/interrupt.h>
   4 #include <linux/sched.h>
   5 #include <linux/device.h> /* for dev_warn */
   6 #include <linux/selection.h>
   7 #include <linux/workqueue.h>
   8 #include <linux/tty.h>
   9 #include <linux/tty_flip.h>
  10 #include <linux/atomic.h>
  11
  12 #include "speakup.h"
  13
  14 /* ------ cut and paste ----- */
  15 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
  16 #define ishardspace(c)      ((c) == ' ')
  17
  18 unsigned short spk_xs, spk_ys, spk_xe, spk_ye; /* our region points */
  19
  20 /* Variables for selection control. */
  21 /* must not be deallocated */
  22 struct vc_data *spk_sel_cons;
  23 /* cleared by clear_selection */
  24 static int sel_start = -1;
  25 static int sel_end;
  26 static int sel_buffer_lth;
  27 static char *sel_buffer;
  28
  29 static unsigned char sel_pos(int n)
  30 {
  31         return inverse_translate(spk_sel_cons,
  32                 screen_glyph(spk_sel_cons, n), 0);
  33 }
  34
  35 void speakup_clear_selection(void)
  36 {
  37         sel_start = -1;
  38 }
  39
  40 /* does screen address p correspond to character at LH/RH edge of screen? */
  41 static int atedge(const int p, int size_row)
  42 {
  43         return !(p % size_row) || !((p + 2) % size_row);
  44 }
  45
  46 /* constrain v such that v <= u */
  47 static unsigned short limit(const unsigned short v, const unsigned short u)
  48 {
  49         return (v > u) ? u : v;
  50 }
  51
  52 int speakup_set_selection(struct tty_struct *tty)
  53 {
  54         int new_sel_start, new_sel_end;
  55         char *bp, *obp;
  56         int i, ps, pe;
  57         struct vc_data *vc = vc_cons[fg_console].d;
  58
  59         spk_xs = limit(spk_xs, vc->vc_cols - 1);
  60         spk_ys = limit(spk_ys, vc->vc_rows - 1);
  61         spk_xe = limit(spk_xe, vc->vc_cols - 1);
  62         spk_ye = limit(spk_ye, vc->vc_rows - 1);
  63         ps = spk_ys * vc->vc_size_row + (spk_xs << 1);
  64         pe = spk_ye * vc->vc_size_row + (spk_xe << 1);
  65
  66         if (ps > pe) {
  67                 /* make sel_start <= sel_end */
  68                 int tmp = ps;
  69
  70                 ps = pe;
  71                 pe = tmp;
  72         }
  73
  74         if (spk_sel_cons != vc_cons[fg_console].d) {
  75                 speakup_clear_selection();
  76                 spk_sel_cons = vc_cons[fg_console].d;
  77                 dev_warn(tty->dev,
  78                         "Selection: mark console not the same as cut\n");
  79                 return -EINVAL;
  80         }
  81
  82         new_sel_start = ps;
  83         new_sel_end = pe;
  84
  85         /* select to end of line if on trailing space */
  86         if (new_sel_end > new_sel_start &&
  87             !atedge(new_sel_end, vc->vc_size_row) &&
  88             ishardspace(sel_pos(new_sel_end))) {
  89                 for (pe = new_sel_end + 2; ; pe += 2)
  90                         if (!ishardspace(sel_pos(pe)) ||
  91                             atedge(pe, vc->vc_size_row))
  92                                 break;
  93                 if (ishardspace(sel_pos(pe)))
  94                         new_sel_end = pe;
  95         }
  96         if ((new_sel_start == sel_start) && (new_sel_end == sel_end))
  97                 return 0; /* no action required */
  98
  99         sel_start = new_sel_start;
 100         sel_end = new_sel_end;
 101         /* Allocate a new buffer before freeing the old one ... */
 102         bp = kmalloc((sel_end-sel_start)/2+1, GFP_ATOMIC);
 103         if (!bp) {
 104                 speakup_clear_selection();
 105                 return -ENOMEM;
 106         }
 107         kfree(sel_buffer);
 108         sel_buffer = bp;
 109
 110         obp = bp;
 111         for (i = sel_start; i <= sel_end; i += 2) {
 112                 *bp = sel_pos(i);
 113                 if (!ishardspace(*bp++))
 114                         obp = bp;
 115                 if (!((i + 2) % vc->vc_size_row)) {
 116                         /* strip trailing blanks from line and add newline,
 117                          * unless non-space at end of line.
 118                          */
 119                         if (obp != bp) {
 120                                 bp = obp;
 121                                 *bp++ = '\r';
 122                         }
 123                         obp = bp;
 124                 }
 125         }
 126         sel_buffer_lth = bp - sel_buffer;
 127         return 0;
 128 }
 129
 130 struct speakup_paste_work {
 131         struct work_struct work;
 132         struct tty_struct *tty;
 133 };
 134
 135 static void __speakup_paste_selection(struct work_struct *work)
 136 {
 137         struct speakup_paste_work *spw =
 138                 container_of(work, struct speakup_paste_work, work);
 139         struct tty_struct *tty = xchg(&spw->tty, NULL);
 140         struct vc_data *vc = (struct vc_data *) tty->driver_data;
 141         int pasted = 0, count;
 142         struct tty_ldisc *ld;
 143         DECLARE_WAITQUEUE(wait, current);
 144
 145         ld = tty_ldisc_ref(tty);
 146         if (!ld)
 147                 goto tty_unref;
 148         tty_buffer_lock_exclusive(&vc->port);
 149
 150         add_wait_queue(&vc->paste_wait, &wait);
 151         while (sel_buffer && sel_buffer_lth > pasted) {
 152                 set_current_state(TASK_INTERRUPTIBLE);
 153                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
 154                         schedule();
 155                         continue;
 156                 }
 157                 count = sel_buffer_lth - pasted;
 158                 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
 159                                               count);
 160                 pasted += count;
 161         }
 162         remove_wait_queue(&vc->paste_wait, &wait);
 163         __set_current_state(TASK_RUNNING);
 164
 165         tty_buffer_unlock_exclusive(&vc->port);
 166         tty_ldisc_deref(ld);
 167 tty_unref:
 168         tty_kref_put(tty);
 169 }
 170
 171 static struct speakup_paste_work speakup_paste_work = {
 172         .work = __WORK_INITIALIZER(speakup_paste_work.work,
 173                                    __speakup_paste_selection)
 174 };
 175
 176 int speakup_paste_selection(struct tty_struct *tty)
 177 {
 178         if (cmpxchg(&speakup_paste_work.tty, NULL, tty) != NULL)
 179                 return -EBUSY;
 180
 181         tty_kref_get(tty);
 182         schedule_work_on(WORK_CPU_UNBOUND, &speakup_paste_work.work);
 183         return 0;
 184 }
 185
 186 void speakup_cancel_paste(void)
 187 {
 188         cancel_work_sync(&speakup_paste_work.work);
 189         tty_kref_put(speakup_paste_work.tty);
 190 }