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| author | Saurabh Sengar <ssengar@linux.microsoft.com> | 2024-03-30 01:51:59 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-11 14:55:53 +0200 |
| commit | 547fa4ffd799ad48bf96e60efd24985adeec35de (patch) | |
| tree | f98466d6121d85e6db5b480fe205111fbb767039 /drivers/uio | |
| parent | e566ed5b64177a0c07b677568f623ed31d23406d (diff) | |
| download | lwn-547fa4ffd799ad48bf96e60efd24985adeec35de.tar.gz lwn-547fa4ffd799ad48bf96e60efd24985adeec35de.zip | |
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.c | 9 |
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; |