[src/trunk]: src/sys/external/bsd/drm2/include/linux Add some more Linux comp...

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

details:   https://anonhg.NetBSD.org/src/rev/6deb3f652c5d
branches:  trunk
changeset: 328355:6deb3f652c5d
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Tue Apr 01 14:55:20 2014 +0000

description:
Add some more Linux completion operations.

Adapted from a patch by nick@.

diffstat:

 sys/external/bsd/drm2/include/linux/completion.h |  82 +++++++++++++++++++++--
 1 files changed, 75 insertions(+), 7 deletions(-)

diffs (109 lines):

diff -r c5b736181780 -r 6deb3f652c5d sys/external/bsd/drm2/include/linux/completion.h
--- a/sys/external/bsd/drm2/include/linux/completion.h  Tue Apr 01 14:28:17 2014 +0000
+++ b/sys/external/bsd/drm2/include/linux/completion.h  Tue Apr 01 14:55:20 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: completion.h,v 1.2 2014/03/18 18:20:43 riastradh Exp $ */
+/*     $NetBSD: completion.h,v 1.3 2014/04/01 14:55:20 riastradh Exp $ */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -146,6 +146,17 @@
        mutex_exit(&completion->c_lock);
 }
 
+static inline void
+_completion_claim(struct completion *completion)
+{
+
+       KASSERT(mutex_owned(&completion->c_lock));
+       if (completion->c_done > 0)
+               completion->c_done--;
+       else
+               KASSERT(completion->c_done == -1);
+}
+
 /*
  * Wait interruptibly with a timeout for someone to call complete or
  * complete_all.
@@ -175,13 +186,8 @@
                start = now;
        }
 
-       /* Claim a completion if it's not open season.  */
-       if (completion->c_done > 0)
-               completion->c_done--;
-       else
-               KASSERT(completion->c_done == -1);
-
        /* Success!  */
+       _completion_claim(completion);
        error = 0;
 
 out:   mutex_exit(&completion->c_lock);
@@ -195,4 +201,66 @@
        }
 }
 
+/*
+ * Wait interruptibly for someone to call complete or complete_all.
+ */
+static inline int
+wait_for_completion_interruptible(struct completion *completion)
+{
+       int error;
+
+       mutex_enter(&completion->c_lock);
+
+       /* Wait until c_done is nonzero.  */
+       while (completion->c_done == 0) {
+               error = cv_wait_sig(&completion->c_cv, &completion->c_lock);
+               if (error)
+                       goto out;
+       }
+
+       /* Success!  */
+       _completion_claim(completion);
+       error = 0;
+
+out:   mutex_exit(&completion->c_lock);
+       if ((error == EINTR) || (error == ERESTART))
+               error = -ERESTARTSYS;
+       return error;
+}
+
+/*
+ * Wait uninterruptibly, except by SIGKILL, for someone to call
+ * complete or complete_all.
+ *
+ * XXX In this implementation, any signal will actually wake us, not
+ * just SIGKILL.
+ */
+static inline int
+wait_for_completion_killable(struct completion *completion)
+{
+
+       return wait_for_completion_interruptible(completion);
+}
+
+/*
+ * Try to claim a completion immediately.  Return true on success, false
+ * if it would block.
+ */
+static inline bool
+try_wait_for_completion(struct completion *completion)
+{
+       bool ok;
+
+       mutex_enter(&completion->c_lock);
+       if (completion->c_done == 0) {
+               ok = false;
+       } else {
+               _completion_claim(completion);
+               ok = true;
+       }
+       mutex_exit(&completion->c_lock);
+
+       return ok;
+}
+
 #endif /* _LINUX_COMPLETION_H_ */