[src/trunk]: src/sys/external/bsd/drm2/linux wait_on_bit

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4b2dd11bf03f
branches:  trunk
changeset: 1028035:4b2dd11bf03f
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Dec 19 01:42:01 2021 +0000

description:
wait_on_bit

diffstat:

 sys/external/bsd/drm2/include/linux/wait_bit.h |   4 ++-
 sys/external/bsd/drm2/linux/linux_wait_bit.c   |  36 ++++++++++++++++++++++++-
 2 files changed, 37 insertions(+), 3 deletions(-)

diffs (82 lines):

diff -r 9a5ccb3972e1 -r 4b2dd11bf03f sys/external/bsd/drm2/include/linux/wait_bit.h
--- a/sys/external/bsd/drm2/include/linux/wait_bit.h    Sun Dec 19 01:41:54 2021 +0000
+++ b/sys/external/bsd/drm2/include/linux/wait_bit.h    Sun Dec 19 01:42:01 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: wait_bit.h,v 1.1 2021/12/19 01:22:15 riastradh Exp $   */
+/*     $NetBSD: wait_bit.h,v 1.2 2021/12/19 01:42:01 riastradh Exp $   */
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -32,6 +32,7 @@
 #ifndef        _LINUX_WAIT_BIT_H_
 #define        _LINUX_WAIT_BIT_H_
 
+#define        wait_on_bit             linux_wait_on_bit
 #define        wait_on_bit_timeout     linux_wait_on_bit_timeout
 #define        wake_up_bit             linux_wake_up_bit
 
@@ -39,6 +40,7 @@
 void   linux_wait_bit_fini(void);
 
 void   wake_up_bit(const volatile unsigned long *, unsigned);
+int    wait_on_bit(const volatile unsigned long *, unsigned, int);
 int    wait_on_bit_timeout(const volatile unsigned long *, unsigned, int,
            unsigned long);
 
diff -r 9a5ccb3972e1 -r 4b2dd11bf03f sys/external/bsd/drm2/linux/linux_wait_bit.c
--- a/sys/external/bsd/drm2/linux/linux_wait_bit.c      Sun Dec 19 01:41:54 2021 +0000
+++ b/sys/external/bsd/drm2/linux/linux_wait_bit.c      Sun Dec 19 01:42:01 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: linux_wait_bit.c,v 1.2 2021/12/19 01:41:54 riastradh Exp $     */
+/*     $NetBSD: linux_wait_bit.c,v 1.3 2021/12/19 01:42:02 riastradh Exp $     */
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux_wait_bit.c,v 1.2 2021/12/19 01:41:54 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_wait_bit.c,v 1.3 2021/12/19 01:42:02 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -115,6 +115,38 @@
 }
 
 int
+wait_on_bit(const volatile unsigned long *bitmap, unsigned bit, int flags)
+{
+       struct waitbitentry *wbe;
+       int error, ret;
+
+       if (test_bit(bit, bitmap))
+               return 0;
+
+       wbe = wait_bit_enter(bitmap, bit);
+
+       while (!test_bit(bit, bitmap)) {
+               if (flags & TASK_UNINTERRUPTIBLE) {
+                       cv_wait(&wbe->cv, &wbe->lock);
+               } else {
+                       error = cv_wait_sig(&wbe->cv, &wbe->lock);
+                       if (error == EINTR || error == ERESTART)
+                               ret = -ERESTARTSYS;
+                       else if (error != 0)
+                               ret = -error;
+                       if (ret)
+                               goto out;
+               }
+       }
+
+       /* Bit is set.  Return zero on success.   */
+       ret = 0;
+
+out:   wait_bit_exit(wbe);
+       return ret;
+}
+
+int
 wait_on_bit_timeout(const volatile unsigned long *bitmap, unsigned bit,
     int flags, unsigned long timeout)
 {