x86/platform/uv/BAU: Fix payload queue setup on UV4 hardware
authorAndrew Banman <abanman@sgi.com>
Wed, 21 Sep 2016 16:09:20 +0000 (11:09 -0500)
committerIngo Molnar <mingo@kernel.org>
Thu, 22 Sep 2016 09:16:15 +0000 (11:16 +0200)
The BAU on UV4 does not need to maintain the payload queue tail pointer. Do
not initialize the tail pointer MMR on UV4.

Note that write_payload_tail is not an abstracted BAU function since it is
an operation specific to pre-UV4 versions. Then we must switch on the UV
version to control its usage, for which we use uvhub_version rather than
is_uv*_hub because it is quicker/more concise.

Signed-off-by: Andrew Banman <abanman@sgi.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mike Travis <travis@sgi.com>
Acked-by: Dimitri Sivanich <sivanich@sgi.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: akpm@linux-foundation.org
Cc: rja@sgi.com
Link: http://lkml.kernel.org/r/1474474161-265604-10-git-send-email-abanman@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/platform/uv/tlb_uv.c

index 72a5de7cf2e046e147893f931ba039cb10588a5e..7ca0e5c314776fe3ac028e83a7212697eaf20ddf 100644 (file)
@@ -1826,11 +1826,19 @@ static void pq_init(int node, int pnode)
 
        first = ops.bau_gpa_to_offset(uv_gpa(pqp));
        last = ops.bau_gpa_to_offset(uv_gpa(pqp + (DEST_Q_SIZE - 1)));
-       tail = first;
-       gnode = uv_gpa_to_gnode(uv_gpa(pqp));
-       first = (gnode << UV_PAYLOADQ_GNODE_SHIFT) | tail;
 
-       write_mmr_payload_tail(pnode, tail);
+       /*
+        * Pre UV4, the gnode is required to locate the payload queue
+        * and the payload queue tail must be maintained by the kernel.
+        */
+       bcp = &per_cpu(bau_control, smp_processor_id());
+       if (bcp->uvhub_version <= 3) {
+               tail = first;
+               gnode = uv_gpa_to_gnode(uv_gpa(pqp));
+               first = (gnode << UV_PAYLOADQ_GNODE_SHIFT) | tail;
+               write_mmr_payload_tail(pnode, tail);
+       }
+
        ops.write_payload_first(pnode, first);
        ops.write_payload_last(pnode, last);
        ops.write_g_sw_ack(pnode, 0xffffUL);