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authorSaurabh Sengar <ssengar@linux.microsoft.com>2024-03-30 01:51:59 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-04-11 14:55:53 +0200
commit547fa4ffd799ad48bf96e60efd24985adeec35de (patch)
treef98466d6121d85e6db5b480fe205111fbb767039 /drivers/uio
parente566ed5b64177a0c07b677568f623ed31d23406d (diff)
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uio_hv_generic: Enable interrupt for low speed VMBus devices
Hyper-V is adding some "specialty" synthetic devices. Instead of writing new kernel-level VMBus drivers for these devices, the devices will be presented to user space via this existing Hyper-V generic UIO driver, so that a user space driver can handle the device. Since these new synthetic devices are low speed devices, they don't support monitor bits and we must use vmbus_setevent() to enable interrupts from the host. Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Long Li <longli@microsoft.com> Link: https://lore.kernel.org/r/1711788723-8593-4-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/uio')
-rw-r--r--drivers/uio/uio_hv_generic.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 4bda6b52e49e..289611c7dfd7 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -84,6 +84,9 @@ hv_uio_irqcontrol(struct uio_info *info, s32 irq_state)
dev->channel->inbound.ring_buffer->interrupt_mask = !irq_state;
virt_mb();
+ if (!dev->channel->offermsg.monitor_allocated && irq_state)
+ vmbus_setevent(dev->channel);
+
return 0;
}
@@ -240,12 +243,6 @@ hv_uio_probe(struct hv_device *dev,
int ret;
size_t ring_size = hv_dev_ring_size(channel);
- /* Communicating with host has to be via shared memory not hypercall */
- if (!channel->offermsg.monitor_allocated) {
- dev_err(&dev->device, "vmbus channel requires hypercall\n");
- return -ENOTSUPP;
- }
-
if (!ring_size)
ring_size = HV_RING_SIZE * PAGE_SIZE;