Messages in this thread Patch in this message | | | Date | Tue, 12 Apr 2011 07:34:10 -0700 | From | Greg KH <> | Subject | [021/105] staging: hv: use sync_bitops when interacting with the hypervisor |
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2.6.38-stable review patch. If anyone has any objections, please let us know.
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From: Olaf Hering <olaf@aepfle.de>
commit 22356585712d1ff08fbfed152edd8b386873b238 upstream.
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> Acked-by: Haiyang Zhang <haiyangz@microsoft.com> Acked-by: Hank Janssen <hjanssen@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.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(-)
--- a/drivers/staging/hv/channel.c +++ b/drivers/staging/hv/channel.c @@ -76,14 +76,14 @@ 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 *) gVmbusConnection.SendInterruptPage + (channel->offermsg.child_relid >> 5)); monitorpage = gVmbusConnection.MonitorPages; 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); @@ -99,7 +99,7 @@ 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 *)gVmbusConnection.SendInterruptPage + (Channel->offermsg.child_relid >> 5)); @@ -107,7 +107,7 @@ static void VmbusChannelClearEvent(struc (struct hv_monitor_page *)gVmbusConnection.MonitorPages; 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); } --- a/drivers/staging/hv/connection.c +++ b/drivers/staging/hv/connection.c @@ -281,7 +281,7 @@ void VmbusOnEvents(void) for (dword = 0; dword < maxdword; dword++) { if (recvInterruptPage[dword]) { for (bit = 0; bit < 32; bit++) { - if (test_and_clear_bit(bit, (unsigned long *)&recvInterruptPage[dword])) { + if (sync_test_and_clear_bit(bit, (unsigned long *)&recvInterruptPage[dword])) { relid = (dword << 5) + bit; DPRINT_DBG(VMBUS, "event detected for relid - %d", relid); @@ -320,7 +320,7 @@ int VmbusPostMessage(void *buffer, size_ int VmbusSetEvent(u32 childRelId) { /* Each u32 represents 32 channels */ - set_bit(childRelId & 31, + sync_set_bit(childRelId & 31, (unsigned long *)gVmbusConnection.SendInterruptPage + (childRelId >> 5)); --- a/drivers/staging/hv/vmbus_drv.c +++ b/drivers/staging/hv/vmbus_drv.c @@ -291,7 +291,7 @@ static int vmbus_on_isr(struct hv_driver 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; } --- a/drivers/staging/hv/vmbus_private.h +++ b/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> /*
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