diff options
| author |   K. Y. Srinivasan <kys@microsoft.com> | 2015-01-09 23:54:32 -0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-25 09:17:57 -0800 |
| commit | 4061ed9e2aaac31daef44f06e9b83143c78b24b2 (patch) | |
| tree | 26043c2e194e4e796fdbcbf95770aa7f74172a68 /drivers/hv/vmbus_drv.c | |
| parent | Drivers: hv: hv_balloon: Don't post pressure status from interrupt context (diff) | |
| download | linux-dev-4061ed9e2aaac31daef44f06e9b83143c78b24b2.tar.xz linux-dev-4061ed9e2aaac31daef44f06e9b83143c78b24b2.zip | |
Drivers: hv: vmbus: Implement a clockevent device
Implement a clockevent device based on the timer support available on
Hyper-V.
In this version of the patch I have addressed Jason's review comments.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/vmbus_drv.c')
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 4d6b26979fbd..7488111ec057 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -32,6 +32,7 @@ #include <linux/completion.h> #include <linux/hyperv.h> #include <linux/kernel_stat.h> +#include <linux/clockchips.h> #include <asm/hyperv.h> #include <asm/hypervisor.h> #include <asm/mshyperv.h> @@ -578,6 +579,34 @@ static void vmbus_onmessage_work(struct work_struct *work) kfree(ctx); } +void hv_process_timer_expiration(struct hv_message *msg, int cpu) +{ + struct clock_event_device *dev = hv_context.clk_evt[cpu]; + + if (dev->event_handler) + dev->event_handler(dev); + + msg->header.message_type = HVMSG_NONE; + + /* + * Make sure the write to MessageType (ie set to + * HVMSG_NONE) happens before we read the + * MessagePending and EOMing. Otherwise, the EOMing + * will not deliver any more messages since there is + * no empty slot + */ + mb(); + + if (msg->header.message_flags.msg_pending) { + /* + * This will cause message queue rescan to + * possibly deliver another msg from the + * hypervisor + */ + wrmsrl(HV_X64_MSR_EOM, 0); + } +} + static void vmbus_on_msg_dpc(unsigned long data) { int cpu = smp_processor_id(); @@ -667,8 +696,12 @@ static void vmbus_isr(void) msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; /* Check if there are actual msgs to be processed */ - if (msg->header.message_type != HVMSG_NONE) - tasklet_schedule(&msg_dpc); + if (msg->header.message_type != HVMSG_NONE) { + if (msg->header.message_type == HVMSG_TIMER_EXPIRED) + hv_process_timer_expiration(msg, cpu); + else + tasklet_schedule(&msg_dpc); + } } /* |