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