RESUBMIT: [PATCH] libibmad: To reserve upper 8 bits of tid used by solaris SRIOV driver

[Boris Chiu <boris.chiu-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>]

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>From 493e8ed95e32f9c3e337f758a979120392c9e412 Mon Sep 17 00:00:00 2001
From: Brendan Doyle <brendan.doyle-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Date: Tue, 12 Mar 2013 19:38:52 +0000
Subject: [PATCH] libibmad: To reserve upper 8 bits of tid used by solaris
 SRIOV driver

Signed-off-by: Brendan Doyle <brendan.doyle-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
 src/mad.c |    8 ++++++++
 src/rpc.c |    2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/mad.c b/src/mad.c
index 70a69dd..fe1305d 100644
--- a/src/mad.c
+++ b/src/mad.c
@@ -50,6 +50,13 @@
 #undef DEBUG
 #define DEBUG	if (ibdebug)	IBWARN
 
+#define GET_IB_USERLAND_TID(tid)	(tid & 0x00000000ffffffff)
+/*
+ * Generate the 64 bit MAD transaction ID. The upper 32 bits are reserved for
+ * use by the kernel. We clear the upper 32 bits here, but MADs received from
+ * the kernel may contain kernel specific data in these bits, consequently
+ * userland TID matching should only be done on the lower 32 bits.
+ */
 uint64_t mad_trid(void)
 {
 	static uint64_t base;
@@ -62,6 +69,7 @@ uint64_t mad_trid(void)
 		trid = random();
 	}
 	next = ++trid | (base << 32);
+	next = GET_IB_USERLAND_TID(next);
 	return next;
 }
 
diff --git a/src/rpc.c b/src/rpc.c
index 5cb13f1..7d93180 100644
--- a/src/rpc.c
+++ b/src/rpc.c
@@ -129,7 +129,7 @@ static int
 _do_madrpc(int port_id, void *sndbuf, void *rcvbuf, int agentid, int len,
 	   int timeout, int max_retries, int *p_error)
 {
-	uint32_t trid;		/* only low 32 bits */
+	uint32_t trid;		/* only low 32 bits - see mad_trid() */
 	int retries;
 	int length, status;
 
-- 
1.7.9.2