- Define a new md function 'casuptr'. This atomically compares and sets

   a pointer that is in user space.  It will be used as the basic primitive
   for a kernel supported user space lock implementation.
 - Implement this function in x86's support.s
 - Provide stubs that return -1 in all other architectures.  Implementations
   will follow along shortly.

Reviewed by:	jake

2 files changed, 16 insertions, 0 deletions

diff --git a/sys/powerpc/aim/machdep.c b/sys/powerpc/aim/machdep.c
index 54661aa..e904fa3 100644
--- a/sys/powerpc/aim/machdep.c
+++ b/sys/powerpc/aim/machdep.c
@@ -752,3 +752,11 @@ kcopy(const void *src, void *dst, size_t len)
 	td->td_pcb->pcb_onfault = oldfault;
 	return (0);
 }
+
+
+intptr_t
+casuptr(intptr_t *p, intptr_t old, intptr_t new)
+{
+	return (-1);
+}
+
diff --git a/sys/powerpc/powerpc/machdep.c b/sys/powerpc/powerpc/machdep.c
index 54661aa..e904fa3 100644
--- a/sys/powerpc/powerpc/machdep.c
+++ b/sys/powerpc/powerpc/machdep.c
@@ -752,3 +752,11 @@ kcopy(const void *src, void *dst, size_t len)
 	td->td_pcb->pcb_onfault = oldfault;
 	return (0);
 }
+
+
+intptr_t
+casuptr(intptr_t *p, intptr_t old, intptr_t new)
+{
+	return (-1);
+}
+