1 files changed, 107 insertions, 0 deletions
diff --git a/plpa-1.3.2/src/libplpa/plpa_api_probe.c b/plpa-1.3.2/src/libplpa/plpa_api_probe.c
new file mode 100644
index 0000000..5f059c3
--- /dev/null
+++ b/plpa-1.3.2/src/libplpa/plpa_api_probe.c
@@ -0,0 +1,107 @@
+/* -*- c -*-
+ *
+ * Copyright (c) 2004-2005 The Trustees of Indiana University.
+ *                         All rights reserved.
+ * Copyright (c) 2004-2005 The Regents of the University of California.
+ *                         All rights reserved.
+ * Copyright (c) 2007-2008 Cisco, Inc.  All rights reserved.
+ * $COPYRIGHT$
+ *
+ * Additional copyrights may follow
+ *
+ * $HEADER$
+ */
+
+#include "plpa_config.h"
+#include "plpa.h"
+#include "plpa_internal.h"
+
+#include <errno.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#if PLPA_WANT_VALGRIND_SUPPORT
+#include "valgrind/memcheck.h"
+#endif
+
+/* Cache, just to make things a little more efficient */
+static PLPA_NAME(api_type_t) cache = PLPA_NAME_CAPS(PROBE_UNSET);
+
+/* The len value we find - not in public header, but used by the lib */
+size_t PLPA_NAME(len) = 0;
+
+int PLPA_NAME(api_probe_init)(void)
+{
+    PLPA_NAME(cpu_set_t) mask;
+    int rc;
+    size_t len;
+    
+    for (len = sizeof(mask); len != 0; len >>= 1) {
+        rc = syscall(__NR_sched_getaffinity, 0, len, &mask);
+        if (rc >= 0) {
+            /* OK, kernel is happy with a get().  Validate w/ a set(). */
+            /* Note that kernel may have told us the "proper" size */
+            size_t tmp = (0 != rc) ? ((size_t) rc) : len;
+            /* Pass mask=NULL, expect errno==EFAULT if tmp was OK
+               as a length */
+#if PLPA_WANT_VALGRIND_SUPPORT
+            /* Lie to Valgrind and say that this memory is addressible
+               so that we don't get a false positive here -- we *know*
+               that 0 is unaddressible; that's the whole point of this
+               test (to see what error NR_sched_set_affinity will
+               return).  So let's not see a warning from Valgrind from
+               something that we know is wrong.  :-) */
+            VALGRIND_MAKE_MEM_DEFINED(0, len);
+#endif
+            rc = syscall(__NR_sched_setaffinity, 0, tmp, NULL);
+#if PLPA_WANT_VALGRIND_SUPPORT
+            VALGRIND_MAKE_MEM_UNDEFINED(0, len);
+            VALGRIND_MAKE_MEM_NOACCESS(0, len);
+#endif
+            if ((rc < 0) && (errno == EFAULT)) {
+                cache = PLPA_NAME_CAPS(PROBE_OK);
+                PLPA_NAME(len) = tmp;
+                rc = 0;
+                break;
+            }
+        }
+        if (errno == ENOSYS) {
+            break; /* No point in looping */
+        }
+    }
+    
+    if (rc >= 0) {
+        /* OK */
+    } else if (errno == ENOSYS) {
+        /* Kernel returns ENOSYS because there is no support for
+           processor affinity */
+        cache = PLPA_NAME_CAPS(PROBE_NOT_SUPPORTED);
+    } else {
+        /* Unknown! */
+        cache = PLPA_NAME_CAPS(PROBE_UNKNOWN);
+    }
+
+    return 0;
+}
+
+
+int PLPA_NAME(api_probe)(PLPA_NAME(api_type_t) *api_type)
+{
+    int ret;
+
+    /* Check to see that we're initialized */
+    if (!PLPA_NAME(initialized)) {
+        if (0 != (ret = PLPA_NAME(init)())) {
+            return ret;
+        }
+    }
+
+    /* Check for bozo arguments */
+    if (NULL == api_type) {
+        return EINVAL;
+    }
+
+    /* All done */
+    *api_type = cache;
+    return 0;
+}