Messages in this thread Patch in this message | | | Date | Wed, 13 Apr 2011 09:09:39 -0700 | From | Greg KH <> | Subject | [16/71] staging: hv: use sync_bitops when interacting with the hypervisor |
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2.6.33-longterm 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.
[Backported to 2.6.32 stable kernel by Haiyang Zhang <haiyangz@microsoft.com>]
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 | 6 ++++-- drivers/staging/hv/Vmbus.c | 2 +- drivers/staging/hv/VmbusPrivate.h | 1 + 4 files changed, 10 insertions(+), 7 deletions(-)
--- a/drivers/staging/hv/Channel.c +++ b/drivers/staging/hv/Channel.c @@ -75,14 +75,14 @@ static void VmbusChannelSetEvent(struct if (Channel->OfferMsg.MonitorAllocated) { /* Each u32 represents 32 channels */ - set_bit(Channel->OfferMsg.ChildRelId & 31, + sync_set_bit(Channel->OfferMsg.ChildRelId & 31, (unsigned long *) gVmbusConnection.SendInterruptPage + (Channel->OfferMsg.ChildRelId >> 5)); monitorPage = gVmbusConnection.MonitorPages; monitorPage++; /* Get the child to parent monitor page */ - set_bit(Channel->MonitorBit, + sync_set_bit(Channel->MonitorBit, (unsigned long *)&monitorPage->TriggerGroup [Channel->MonitorGroup].Pending); @@ -102,7 +102,7 @@ static void VmbusChannelClearEvent(struc if (Channel->OfferMsg.MonitorAllocated) { /* Each u32 represents 32 channels */ - clear_bit(Channel->OfferMsg.ChildRelId & 31, + sync_clear_bit(Channel->OfferMsg.ChildRelId & 31, (unsigned long *)gVmbusConnection.SendInterruptPage + (Channel->OfferMsg.ChildRelId >> 5)); @@ -110,7 +110,7 @@ static void VmbusChannelClearEvent(struc (struct hv_monitor_page *)gVmbusConnection.MonitorPages; monitorPage++; /* Get the child to parent monitor page */ - clear_bit(Channel->MonitorBit, + sync_clear_bit(Channel->MonitorBit, (unsigned long *)&monitorPage->TriggerGroup [Channel->MonitorGroup].Pending); } --- a/drivers/staging/hv/Connection.c +++ b/drivers/staging/hv/Connection.c @@ -284,7 +284,9 @@ 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); @@ -329,7 +331,7 @@ int VmbusSetEvent(u32 childRelId) DPRINT_ENTER(VMBUS); /* 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.c +++ b/drivers/staging/hv/Vmbus.c @@ -254,7 +254,7 @@ static int VmbusOnISR(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/VmbusPrivate.h +++ b/drivers/staging/hv/VmbusPrivate.h @@ -32,6 +32,7 @@ #include "ChannelInterface.h" #include "RingBuffer.h" #include <linux/list.h> +#include <asm/sync_bitops.h> /*
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