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path: root/drivers/staging/speakup/selection.c
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Diffstat (limited to 'drivers/staging/speakup/selection.c')
-rw-r--r--drivers/staging/speakup/selection.c212
1 files changed, 86 insertions, 126 deletions
diff --git a/drivers/staging/speakup/selection.c b/drivers/staging/speakup/selection.c
index 0ed1fefee0e9..a8b4d0c5ab7e 100644
--- a/drivers/staging/speakup/selection.c
+++ b/drivers/staging/speakup/selection.c
@@ -9,178 +9,138 @@
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/atomic.h>
+#include <linux/console.h>
#include "speakup.h"
-/* ------ cut and paste ----- */
-/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
-#define ishardspace(c) ((c) == ' ')
-
unsigned short spk_xs, spk_ys, spk_xe, spk_ye; /* our region points */
-
-/* Variables for selection control. */
-/* must not be deallocated */
struct vc_data *spk_sel_cons;
-/* cleared by clear_selection */
-static int sel_start = -1;
-static int sel_end;
-static int sel_buffer_lth;
-static char *sel_buffer;
-static unsigned char sel_pos(int n)
-{
- return inverse_translate(spk_sel_cons,
- screen_glyph(spk_sel_cons, n), 0);
-}
+struct speakup_selection_work {
+ struct work_struct work;
+ struct tiocl_selection sel;
+ struct tty_struct *tty;
+};
void speakup_clear_selection(void)
{
- sel_start = -1;
+ console_lock();
+ clear_selection();
+ console_unlock();
}
-/* does screen address p correspond to character at LH/RH edge of screen? */
-static int atedge(const int p, int size_row)
+static void __speakup_set_selection(struct work_struct *work)
{
- return !(p % size_row) || !((p + 2) % size_row);
-}
+ struct speakup_selection_work *ssw =
+ container_of(work, struct speakup_selection_work, work);
-/* constrain v such that v <= u */
-static unsigned short limit(const unsigned short v, const unsigned short u)
-{
- return (v > u) ? u : v;
-}
+ struct tty_struct *tty;
+ struct tiocl_selection sel;
-int speakup_set_selection(struct tty_struct *tty)
-{
- int new_sel_start, new_sel_end;
- char *bp, *obp;
- int i, ps, pe;
- struct vc_data *vc = vc_cons[fg_console].d;
+ sel = ssw->sel;
- spk_xs = limit(spk_xs, vc->vc_cols - 1);
- spk_ys = limit(spk_ys, vc->vc_rows - 1);
- spk_xe = limit(spk_xe, vc->vc_cols - 1);
- spk_ye = limit(spk_ye, vc->vc_rows - 1);
- ps = spk_ys * vc->vc_size_row + (spk_xs << 1);
- pe = spk_ye * vc->vc_size_row + (spk_xe << 1);
+ /* this ensures we copy sel before releasing the lock below */
+ rmb();
- if (ps > pe) /* make sel_start <= sel_end */
- swap(ps, pe);
+ /* release the lock by setting tty of the struct to NULL */
+ tty = xchg(&ssw->tty, NULL);
if (spk_sel_cons != vc_cons[fg_console].d) {
- speakup_clear_selection();
spk_sel_cons = vc_cons[fg_console].d;
- dev_warn(tty->dev,
- "Selection: mark console not the same as cut\n");
- return -EINVAL;
+ pr_warn("Selection: mark console not the same as cut\n");
+ goto unref;
}
- new_sel_start = ps;
- new_sel_end = pe;
-
- /* select to end of line if on trailing space */
- if (new_sel_end > new_sel_start &&
- !atedge(new_sel_end, vc->vc_size_row) &&
- ishardspace(sel_pos(new_sel_end))) {
- for (pe = new_sel_end + 2; ; pe += 2)
- if (!ishardspace(sel_pos(pe)) ||
- atedge(pe, vc->vc_size_row))
- break;
- if (ishardspace(sel_pos(pe)))
- new_sel_end = pe;
- }
- if ((new_sel_start == sel_start) && (new_sel_end == sel_end))
- return 0; /* no action required */
-
- sel_start = new_sel_start;
- sel_end = new_sel_end;
- /* Allocate a new buffer before freeing the old one ... */
- bp = kmalloc((sel_end - sel_start) / 2 + 1, GFP_ATOMIC);
- if (!bp) {
- speakup_clear_selection();
- return -ENOMEM;
- }
- kfree(sel_buffer);
- sel_buffer = bp;
-
- obp = bp;
- for (i = sel_start; i <= sel_end; i += 2) {
- *bp = sel_pos(i);
- if (!ishardspace(*bp++))
- obp = bp;
- if (!((i + 2) % vc->vc_size_row)) {
- /* strip trailing blanks from line and add newline,
- * unless non-space at end of line.
- */
- if (obp != bp) {
- bp = obp;
- *bp++ = '\r';
- }
- obp = bp;
- }
+ console_lock();
+ set_selection_kernel(&sel, tty);
+ console_unlock();
+
+unref:
+ tty_kref_put(tty);
+}
+
+static struct speakup_selection_work speakup_sel_work = {
+ .work = __WORK_INITIALIZER(speakup_sel_work.work,
+ __speakup_set_selection)
+};
+
+int speakup_set_selection(struct tty_struct *tty)
+{
+ /* we get kref here first in order to avoid a subtle race when
+ * cancelling selection work. getting kref first establishes the
+ * invariant that if speakup_sel_work.tty is not NULL when
+ * speakup_cancel_selection() is called, it must be the case that a put
+ * kref is pending.
+ */
+ tty_kref_get(tty);
+ if (cmpxchg(&speakup_sel_work.tty, NULL, tty)) {
+ tty_kref_put(tty);
+ return -EBUSY;
}
- sel_buffer_lth = bp - sel_buffer;
+ /* now we have the 'lock' by setting tty member of
+ * speakup_selection_work. wmb() ensures that writes to
+ * speakup_sel_work don't happen before cmpxchg() above.
+ */
+ wmb();
+
+ speakup_sel_work.sel.xs = spk_xs + 1;
+ speakup_sel_work.sel.ys = spk_ys + 1;
+ speakup_sel_work.sel.xe = spk_xe + 1;
+ speakup_sel_work.sel.ye = spk_ye + 1;
+ speakup_sel_work.sel.sel_mode = TIOCL_SELCHAR;
+
+ schedule_work_on(WORK_CPU_UNBOUND, &speakup_sel_work.work);
+
return 0;
}
-struct speakup_paste_work {
- struct work_struct work;
+void speakup_cancel_selection(void)
+{
struct tty_struct *tty;
-};
+
+ cancel_work_sync(&speakup_sel_work.work);
+ /* setting to null so that if work fails to run and we cancel it,
+ * we can run it again without getting EBUSY forever from there on.
+ * we need to use xchg here to avoid race with speakup_set_selection()
+ */
+ tty = xchg(&speakup_sel_work.tty, NULL);
+ if (tty)
+ tty_kref_put(tty);
+}
static void __speakup_paste_selection(struct work_struct *work)
{
- struct speakup_paste_work *spw =
- container_of(work, struct speakup_paste_work, work);
- struct tty_struct *tty = xchg(&spw->tty, NULL);
- struct vc_data *vc = (struct vc_data *)tty->driver_data;
- int pasted = 0, count;
- struct tty_ldisc *ld;
- DECLARE_WAITQUEUE(wait, current);
-
- ld = tty_ldisc_ref(tty);
- if (!ld)
- goto tty_unref;
- tty_buffer_lock_exclusive(&vc->port);
-
- add_wait_queue(&vc->paste_wait, &wait);
- while (sel_buffer && sel_buffer_lth > pasted) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (tty_throttled(tty)) {
- schedule();
- continue;
- }
- count = sel_buffer_lth - pasted;
- count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
- count);
- pasted += count;
- }
- remove_wait_queue(&vc->paste_wait, &wait);
- __set_current_state(TASK_RUNNING);
+ struct speakup_selection_work *ssw =
+ container_of(work, struct speakup_selection_work, work);
+ struct tty_struct *tty = xchg(&ssw->tty, NULL);
- tty_buffer_unlock_exclusive(&vc->port);
- tty_ldisc_deref(ld);
-tty_unref:
+ paste_selection(tty);
tty_kref_put(tty);
}
-static struct speakup_paste_work speakup_paste_work = {
+static struct speakup_selection_work speakup_paste_work = {
.work = __WORK_INITIALIZER(speakup_paste_work.work,
__speakup_paste_selection)
};
int speakup_paste_selection(struct tty_struct *tty)
{
- if (cmpxchg(&speakup_paste_work.tty, NULL, tty))
+ tty_kref_get(tty);
+ if (cmpxchg(&speakup_paste_work.tty, NULL, tty)) {
+ tty_kref_put(tty);
return -EBUSY;
+ }
- tty_kref_get(tty);
schedule_work_on(WORK_CPU_UNBOUND, &speakup_paste_work.work);
return 0;
}
void speakup_cancel_paste(void)
{
+ struct tty_struct *tty;
+
cancel_work_sync(&speakup_paste_work.work);
- tty_kref_put(speakup_paste_work.tty);
+ tty = xchg(&speakup_paste_work.tty, NULL);
+ if (tty)
+ tty_kref_put(tty);
}