Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966019Ab3GSFoe (ORCPT ); Fri, 19 Jul 2013 01:44:34 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39671 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965581Ab3GSF03 (ORCPT ); Fri, 19 Jul 2013 01:26:29 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Wang , Haiyang Zhang , "K. Y. Srinivasan" Subject: [ 17/72] drivers: hv: switch to use mb() instead of smp_mb() Date: Thu, 18 Jul 2013 22:25:34 -0700 Message-Id: <20130719052601.042108041@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <20130719052559.852627424@linuxfoundation.org> References: <20130719052559.852627424@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2531 Lines: 87 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang commit 35848f68b07df3f917cb13fc3c134718669f569b upstream. Even if guest were compiled without SMP support, it could not assume that host wasn't. So switch to use mb() instead of smp_mb() to force memory barriers for UP guest. Signed-off-by: Jason Wang Cc: Haiyang Zhang Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/ring_buffer.c | 10 +++++----- drivers/hv/vmbus_drv.c | 2 +- 2 files changed, 6 insertions(+), 6 deletions(-) --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -32,7 +32,7 @@ void hv_begin_read(struct hv_ring_buffer_info *rbi) { rbi->ring_buffer->interrupt_mask = 1; - smp_mb(); + mb(); } u32 hv_end_read(struct hv_ring_buffer_info *rbi) @@ -41,7 +41,7 @@ u32 hv_end_read(struct hv_ring_buffer_in u32 write; rbi->ring_buffer->interrupt_mask = 0; - smp_mb(); + mb(); /* * Now check to see if the ring buffer is still empty. @@ -71,7 +71,7 @@ u32 hv_end_read(struct hv_ring_buffer_in static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi) { - smp_mb(); + mb(); if (rbi->ring_buffer->interrupt_mask) return false; @@ -442,7 +442,7 @@ int hv_ringbuffer_write(struct hv_ring_b sizeof(u64)); /* Issue a full memory barrier before updating the write index */ - smp_mb(); + mb(); /* Now, update the write location */ hv_set_next_write_location(outring_info, next_write_location); @@ -549,7 +549,7 @@ int hv_ringbuffer_read(struct hv_ring_bu /* Make sure all reads are done before we update the read index since */ /* the writer may start writing to the read area once the read index */ /*is updated */ - smp_mb(); + mb(); /* Update the read index */ hv_set_next_read_location(inring_info, next_read_location); --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -434,7 +434,7 @@ static void vmbus_on_msg_dpc(unsigned lo * will not deliver any more messages since there is * no empty slot */ - smp_mb(); + mb(); if (msg->header.message_flags.msg_pending) { /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/