[PATCH] Properly assign to packet header (PR hsa/70394)

[Martin Liška]

Hello.

Following patch initializes whole packet->header field, which is eventually 
stored
to a packet in atomic manner. The function mechanism was adopted from the HSA 
runtime
manual.

I've been running bootstrap and regression tests.
Ready to be installed after it finishes?

Thanks,
Martin

libgomp/ChangeLog:

2016-03-24  Martin Liska  <mli...@suse.cz>

        * plugin/plugin-hsa.c (packet_store_release): New function
        that is taken from the HSA runtime manual.
        (GOMP_OFFLOAD_run): Use the function.
---
 libgomp/plugin/plugin-hsa.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/libgomp/plugin/plugin-hsa.c b/libgomp/plugin/plugin-hsa.c
index f7ef600..0b3b67a 100644
--- a/libgomp/plugin/plugin-hsa.c
+++ b/libgomp/plugin/plugin-hsa.c
@@ -1185,6 +1185,14 @@ failure:
   return false;
 }
 
+/* Atomically store pair of uint16_t values (HEADER and REST) to a PACKET.  */
+
+void
+packet_store_release (uint32_t* packet, uint16_t header, uint16_t rest)
+{
+  __atomic_store_n (packet, header | (rest << 16), __ATOMIC_RELEASE);
+}
+
 /* Part of the libgomp plugin interface.  Run a kernel on device N and pass it
    an array of pointers in VARS as a parameter.  The kernel is identified by
    FN_PTR which must point to a kernel_info structure.  */
@@ -1232,7 +1240,6 @@ GOMP_OFFLOAD_run (int n, void *fn_ptr, void *vars, void 
**args)
           + index % agent->command_q->size;
 
   memset (((uint8_t *) packet) + 4, 0, sizeof (*packet) - 4);
-  packet->setup |= (uint16_t) 1 << HSA_KERNEL_DISPATCH_PACKET_SETUP_DIMENSIONS;
   packet->grid_size_x = kla->gdims[0];
   uint32_t wgs = kla->wdims[0];
   if (wgs == 0)
@@ -1275,7 +1282,9 @@ GOMP_OFFLOAD_run (int n, void *fn_ptr, void *vars, void 
**args)
 
   HSA_DEBUG ("Going to dispatch kernel %s\n", kernel->name);
 
-  __atomic_store_n ((uint16_t *) (&packet->header), header, __ATOMIC_RELEASE);
+  packet_store_release ((uint32_t *) packet, header,
+                       1 << HSA_KERNEL_DISPATCH_PACKET_SETUP_DIMENSIONS);
+
   hsa_signal_store_release (agent->command_q->doorbell_signal, index);
 
   /* TODO: GPU agents in Carrizo APUs cannot properly update L2 cache for
-- 
2.7.1