12067fd92SSamuel Thibault // SPDX-License-Identifier: GPL-2.0
22067fd92SSamuel Thibault #include <linux/slab.h> /* for kmalloc */
32067fd92SSamuel Thibault #include <linux/consolemap.h>
42067fd92SSamuel Thibault #include <linux/interrupt.h>
52067fd92SSamuel Thibault #include <linux/sched.h>
62067fd92SSamuel Thibault #include <linux/device.h> /* for dev_warn */
72067fd92SSamuel Thibault #include <linux/selection.h>
82067fd92SSamuel Thibault #include <linux/workqueue.h>
92067fd92SSamuel Thibault #include <linux/tty.h>
102067fd92SSamuel Thibault #include <linux/tty_flip.h>
112067fd92SSamuel Thibault #include <linux/atomic.h>
122067fd92SSamuel Thibault #include <linux/console.h>
132067fd92SSamuel Thibault
142067fd92SSamuel Thibault #include "speakup.h"
152067fd92SSamuel Thibault
162067fd92SSamuel Thibault unsigned short spk_xs, spk_ys, spk_xe, spk_ye; /* our region points */
172067fd92SSamuel Thibault struct vc_data *spk_sel_cons;
182067fd92SSamuel Thibault
192067fd92SSamuel Thibault struct speakup_selection_work {
202067fd92SSamuel Thibault struct work_struct work;
212067fd92SSamuel Thibault struct tiocl_selection sel;
222067fd92SSamuel Thibault struct tty_struct *tty;
232067fd92SSamuel Thibault };
242067fd92SSamuel Thibault
__speakup_set_selection(struct work_struct * work)252067fd92SSamuel Thibault static void __speakup_set_selection(struct work_struct *work)
262067fd92SSamuel Thibault {
272067fd92SSamuel Thibault struct speakup_selection_work *ssw =
282067fd92SSamuel Thibault container_of(work, struct speakup_selection_work, work);
292067fd92SSamuel Thibault
302067fd92SSamuel Thibault struct tty_struct *tty;
312067fd92SSamuel Thibault struct tiocl_selection sel;
322067fd92SSamuel Thibault
332067fd92SSamuel Thibault sel = ssw->sel;
342067fd92SSamuel Thibault
352067fd92SSamuel Thibault /* this ensures we copy sel before releasing the lock below */
362067fd92SSamuel Thibault rmb();
372067fd92SSamuel Thibault
382067fd92SSamuel Thibault /* release the lock by setting tty of the struct to NULL */
392067fd92SSamuel Thibault tty = xchg(&ssw->tty, NULL);
402067fd92SSamuel Thibault
412067fd92SSamuel Thibault if (spk_sel_cons != vc_cons[fg_console].d) {
422067fd92SSamuel Thibault spk_sel_cons = vc_cons[fg_console].d;
432067fd92SSamuel Thibault pr_warn("Selection: mark console not the same as cut\n");
442067fd92SSamuel Thibault goto unref;
452067fd92SSamuel Thibault }
462067fd92SSamuel Thibault
47*640969a6SSamuel Thibault console_lock();
48*640969a6SSamuel Thibault clear_selection();
49*640969a6SSamuel Thibault console_unlock();
50*640969a6SSamuel Thibault
512067fd92SSamuel Thibault set_selection_kernel(&sel, tty);
522067fd92SSamuel Thibault
532067fd92SSamuel Thibault unref:
542067fd92SSamuel Thibault tty_kref_put(tty);
552067fd92SSamuel Thibault }
562067fd92SSamuel Thibault
572067fd92SSamuel Thibault static struct speakup_selection_work speakup_sel_work = {
582067fd92SSamuel Thibault .work = __WORK_INITIALIZER(speakup_sel_work.work,
592067fd92SSamuel Thibault __speakup_set_selection)
602067fd92SSamuel Thibault };
612067fd92SSamuel Thibault
speakup_set_selection(struct tty_struct * tty)622067fd92SSamuel Thibault int speakup_set_selection(struct tty_struct *tty)
632067fd92SSamuel Thibault {
642067fd92SSamuel Thibault /* we get kref here first in order to avoid a subtle race when
652067fd92SSamuel Thibault * cancelling selection work. getting kref first establishes the
662067fd92SSamuel Thibault * invariant that if speakup_sel_work.tty is not NULL when
672067fd92SSamuel Thibault * speakup_cancel_selection() is called, it must be the case that a put
682067fd92SSamuel Thibault * kref is pending.
692067fd92SSamuel Thibault */
702067fd92SSamuel Thibault tty_kref_get(tty);
712067fd92SSamuel Thibault if (cmpxchg(&speakup_sel_work.tty, NULL, tty)) {
722067fd92SSamuel Thibault tty_kref_put(tty);
732067fd92SSamuel Thibault return -EBUSY;
742067fd92SSamuel Thibault }
752067fd92SSamuel Thibault /* now we have the 'lock' by setting tty member of
762067fd92SSamuel Thibault * speakup_selection_work. wmb() ensures that writes to
772067fd92SSamuel Thibault * speakup_sel_work don't happen before cmpxchg() above.
782067fd92SSamuel Thibault */
792067fd92SSamuel Thibault wmb();
802067fd92SSamuel Thibault
812067fd92SSamuel Thibault speakup_sel_work.sel.xs = spk_xs + 1;
822067fd92SSamuel Thibault speakup_sel_work.sel.ys = spk_ys + 1;
832067fd92SSamuel Thibault speakup_sel_work.sel.xe = spk_xe + 1;
842067fd92SSamuel Thibault speakup_sel_work.sel.ye = spk_ye + 1;
852067fd92SSamuel Thibault speakup_sel_work.sel.sel_mode = TIOCL_SELCHAR;
862067fd92SSamuel Thibault
872067fd92SSamuel Thibault schedule_work_on(WORK_CPU_UNBOUND, &speakup_sel_work.work);
882067fd92SSamuel Thibault
892067fd92SSamuel Thibault return 0;
902067fd92SSamuel Thibault }
912067fd92SSamuel Thibault
speakup_cancel_selection(void)922067fd92SSamuel Thibault void speakup_cancel_selection(void)
932067fd92SSamuel Thibault {
942067fd92SSamuel Thibault struct tty_struct *tty;
952067fd92SSamuel Thibault
962067fd92SSamuel Thibault cancel_work_sync(&speakup_sel_work.work);
972067fd92SSamuel Thibault /* setting to null so that if work fails to run and we cancel it,
982067fd92SSamuel Thibault * we can run it again without getting EBUSY forever from there on.
992067fd92SSamuel Thibault * we need to use xchg here to avoid race with speakup_set_selection()
1002067fd92SSamuel Thibault */
1012067fd92SSamuel Thibault tty = xchg(&speakup_sel_work.tty, NULL);
1022067fd92SSamuel Thibault if (tty)
1032067fd92SSamuel Thibault tty_kref_put(tty);
1042067fd92SSamuel Thibault }
1052067fd92SSamuel Thibault
__speakup_paste_selection(struct work_struct * work)1062067fd92SSamuel Thibault static void __speakup_paste_selection(struct work_struct *work)
1072067fd92SSamuel Thibault {
1082067fd92SSamuel Thibault struct speakup_selection_work *ssw =
1092067fd92SSamuel Thibault container_of(work, struct speakup_selection_work, work);
1102067fd92SSamuel Thibault struct tty_struct *tty = xchg(&ssw->tty, NULL);
1112067fd92SSamuel Thibault
1122067fd92SSamuel Thibault paste_selection(tty);
1132067fd92SSamuel Thibault tty_kref_put(tty);
1142067fd92SSamuel Thibault }
1152067fd92SSamuel Thibault
1162067fd92SSamuel Thibault static struct speakup_selection_work speakup_paste_work = {
1172067fd92SSamuel Thibault .work = __WORK_INITIALIZER(speakup_paste_work.work,
1182067fd92SSamuel Thibault __speakup_paste_selection)
1192067fd92SSamuel Thibault };
1202067fd92SSamuel Thibault
speakup_paste_selection(struct tty_struct * tty)1212067fd92SSamuel Thibault int speakup_paste_selection(struct tty_struct *tty)
1222067fd92SSamuel Thibault {
1232067fd92SSamuel Thibault tty_kref_get(tty);
1242067fd92SSamuel Thibault if (cmpxchg(&speakup_paste_work.tty, NULL, tty)) {
1252067fd92SSamuel Thibault tty_kref_put(tty);
1262067fd92SSamuel Thibault return -EBUSY;
1272067fd92SSamuel Thibault }
1282067fd92SSamuel Thibault
1292067fd92SSamuel Thibault schedule_work_on(WORK_CPU_UNBOUND, &speakup_paste_work.work);
1302067fd92SSamuel Thibault return 0;
1312067fd92SSamuel Thibault }
1322067fd92SSamuel Thibault
speakup_cancel_paste(void)1332067fd92SSamuel Thibault void speakup_cancel_paste(void)
1342067fd92SSamuel Thibault {
1352067fd92SSamuel Thibault struct tty_struct *tty;
1362067fd92SSamuel Thibault
1372067fd92SSamuel Thibault cancel_work_sync(&speakup_paste_work.work);
1382067fd92SSamuel Thibault tty = xchg(&speakup_paste_work.tty, NULL);
1392067fd92SSamuel Thibault if (tty)
1402067fd92SSamuel Thibault tty_kref_put(tty);
1412067fd92SSamuel Thibault }
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