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 <asm/cmpxchg.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                 ps = pe;
  70                 pe = tmp;
  71         }
  72
  73         if (spk_sel_cons != vc_cons[fg_console].d) {
  74                 speakup_clear_selection();
  75                 spk_sel_cons = vc_cons[fg_console].d;
  76                 dev_warn(tty->dev,
  77                         "Selection: mark console not the same as cut\n");
  78                 return -EINVAL;
  79         }
  80
  81         new_sel_start = ps;
  82         new_sel_end = pe;
  83
  84         /* select to end of line if on trailing space */
  85         if (new_sel_end > new_sel_start &&
  86             !atedge(new_sel_end, vc->vc_size_row) &&
  87             ishardspace(sel_pos(new_sel_end))) {
  88                 for (pe = new_sel_end + 2; ; pe += 2)
  89                         if (!ishardspace(sel_pos(pe)) ||
  90                             atedge(pe, vc->vc_size_row))
  91                                 break;
  92                 if (ishardspace(sel_pos(pe)))
  93                         new_sel_end = pe;
  94         }
  95         if ((new_sel_start == sel_start) && (new_sel_end == sel_end))
  96                 return 0; /* no action required */
  97
  98         sel_start = new_sel_start;
  99         sel_end = new_sel_end;
 100         /* Allocate a new buffer before freeing the old one ... */
 101         bp = kmalloc((sel_end-sel_start)/2+1, GFP_ATOMIC);
 102         if (!bp) {
 103                 speakup_clear_selection();
 104                 return -ENOMEM;
 105         }
 106         kfree(sel_buffer);
 107         sel_buffer = bp;
 108
 109         obp = bp;
 110         for (i = sel_start; i <= sel_end; i += 2) {
 111                 *bp = sel_pos(i);
 112                 if (!ishardspace(*bp++))
 113                         obp = bp;
 114                 if (!((i + 2) % vc->vc_size_row)) {
 115                         /* strip trailing blanks from line and add newline,
 116                            unless non-space at end of line. */
 117                         if (obp != bp) {
 118                                 bp = obp;
 119                                 *bp++ = '\r';
 120                         }
 121                         obp = bp;
 122                 }
 123         }
 124         sel_buffer_lth = bp - sel_buffer;
 125         return 0;
 126 }
 127
 128 struct speakup_paste_work {
 129         struct work_struct work;
 130         struct tty_struct *tty;
 131 };
 132
 133 static void __speakup_paste_selection(struct work_struct *work)
 134 {
 135         struct speakup_paste_work *spw =
 136                 container_of(work, struct speakup_paste_work, work);
 137         struct tty_struct *tty = xchg(&spw->tty, NULL);
 138         struct vc_data *vc = (struct vc_data *) tty->driver_data;
 139         int pasted = 0, count;
 140         struct tty_ldisc *ld;
 141         DECLARE_WAITQUEUE(wait, current);
 142
 143         ld = tty_ldisc_ref_wait(tty);
 144         tty_buffer_lock_exclusive(&vc->port);
 145
 146         add_wait_queue(&vc->paste_wait, &wait);
 147         while (sel_buffer && sel_buffer_lth > pasted) {
 148                 set_current_state(TASK_INTERRUPTIBLE);
 149                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
 150                         schedule();
 151                         continue;
 152                 }
 153                 count = sel_buffer_lth - pasted;
 154                 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
 155                                               count);
 156                 pasted += count;
 157         }
 158         remove_wait_queue(&vc->paste_wait, &wait);
 159         current->state = TASK_RUNNING;
 160
 161         tty_buffer_unlock_exclusive(&vc->port);
 162         tty_ldisc_deref(ld);
 163         tty_kref_put(tty);
 164 }
 165
 166 static struct speakup_paste_work speakup_paste_work = {
 167         .work = __WORK_INITIALIZER(speakup_paste_work.work,
 168                                    __speakup_paste_selection)
 169 };
 170
 171 int speakup_paste_selection(struct tty_struct *tty)
 172 {
 173         if (cmpxchg(&speakup_paste_work.tty, NULL, tty) != NULL)
 174                 return -EBUSY;
 175
 176         tty_kref_get(tty);
 177         schedule_work_on(WORK_CPU_UNBOUND, &speakup_paste_work.work);
 178         return 0;
 179 }
 180
 181 void speakup_cancel_paste(void)
 182 {
 183         cancel_work_sync(&speakup_paste_work.work);
 184         tty_kref_put(speakup_paste_work.tty);
 185 }