From: Olaf Hering <olaf@aepfle.de>
To: Hank Janssen <hjanssen@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Greg Kroah-Hartman <gregkh@suse.de>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] hv: use sync_bitops when interacting with the hypervisor
Date: Mon, 21 Mar 2011 14:41:37 +0100 [thread overview]
Message-ID: <20110321134137.GA29305@aepfle.de> (raw)
Locking is required when tweaking bits located in a shared page, use the
sync_ version of bitops. Without this change vmbus_on_event() will miss
events and as a result, vmbus_isr() will not schedule the receive tasklet.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
drivers/staging/hv/channel.c | 8 ++++----
drivers/staging/hv/connection.c | 4 ++--
drivers/staging/hv/vmbus_drv.c | 2 +-
drivers/staging/hv/vmbus_private.h | 1 +
4 files changed, 8 insertions(+), 7 deletions(-)
Index: linux-2.6/drivers/staging/hv/channel.c
===================================================================
--- linux-2.6.orig/drivers/staging/hv/channel.c
+++ linux-2.6/drivers/staging/hv/channel.c
@@ -81,14 +81,14 @@ static void vmbus_setevent(struct vmbus_
if (channel->offermsg.monitor_allocated) {
/* Each u32 represents 32 channels */
- set_bit(channel->offermsg.child_relid & 31,
+ sync_set_bit(channel->offermsg.child_relid & 31,
(unsigned long *) vmbus_connection.send_int_page +
(channel->offermsg.child_relid >> 5));
monitorpage = vmbus_connection.monitor_pages;
monitorpage++; /* Get the child to parent monitor page */
- set_bit(channel->monitor_bit,
+ sync_set_bit(channel->monitor_bit,
(unsigned long *)&monitorpage->trigger_group
[channel->monitor_grp].pending);
@@ -104,7 +104,7 @@ static void VmbusChannelClearEvent(struc
if (Channel->offermsg.monitor_allocated) {
/* Each u32 represents 32 channels */
- clear_bit(Channel->offermsg.child_relid & 31,
+ sync_clear_bit(Channel->offermsg.child_relid & 31,
(unsigned long *)vmbus_connection.send_int_page +
(Channel->offermsg.child_relid >> 5));
@@ -112,7 +112,7 @@ static void VmbusChannelClearEvent(struc
vmbus_connection.monitor_pages;
monitorPage++; /* Get the child to parent monitor page */
- clear_bit(Channel->monitor_bit,
+ sync_clear_bit(Channel->monitor_bit,
(unsigned long *)&monitorPage->trigger_group
[Channel->monitor_grp].Pending);
}
Index: linux-2.6/drivers/staging/hv/connection.c
===================================================================
--- linux-2.6.orig/drivers/staging/hv/connection.c
+++ linux-2.6/drivers/staging/hv/connection.c
@@ -296,7 +296,7 @@ void vmbus_on_event(unsigned long data)
for (dword = 0; dword < maxdword; dword++) {
if (recv_int_page[dword]) {
for (bit = 0; bit < 32; bit++) {
- if (test_and_clear_bit(bit,
+ if (sync_test_and_clear_bit(bit,
(unsigned long *)
&recv_int_page[dword])) {
relid = (dword << 5) + bit;
@@ -338,7 +338,7 @@ int vmbus_post_msg(void *buffer, size_t
int vmbus_set_event(u32 child_relid)
{
/* Each u32 represents 32 channels */
- set_bit(child_relid & 31,
+ sync_set_bit(child_relid & 31,
(unsigned long *)vmbus_connection.send_int_page +
(child_relid >> 5));
Index: linux-2.6/drivers/staging/hv/vmbus_drv.c
===================================================================
--- linux-2.6.orig/drivers/staging/hv/vmbus_drv.c
+++ linux-2.6/drivers/staging/hv/vmbus_drv.c
@@ -254,7 +254,7 @@ static int vmbus_on_isr(void)
event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
/* Since we are a child, we only need to check bit 0 */
- if (test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
+ if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
DPRINT_DBG(VMBUS, "received event %d", event->flags32[0]);
ret |= 0x2;
}
Index: linux-2.6/drivers/staging/hv/vmbus_private.h
===================================================================
--- linux-2.6.orig/drivers/staging/hv/vmbus_private.h
+++ linux-2.6/drivers/staging/hv/vmbus_private.h
@@ -31,6 +31,7 @@
#include "channel_mgmt.h"
#include "ring_buffer.h"
#include <linux/list.h>
+#include <asm/sync_bitops.h>
/*
next reply other threads:[~2011-03-21 13:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-21 13:41 Olaf Hering [this message]
2011-03-21 14:09 ` [PATCH] hv: use sync_bitops when interacting with the hypervisor Greg KH
2011-03-21 14:16 ` Haiyang Zhang
2011-03-21 14:58 ` Hank Janssen
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