Allow setting size of ring buffer for host communication via
module parameter.
Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
---
drivers/uio/uio_hv_generic.c | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 8d5f529a1dc1..24f8689fdb14 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -39,6 +39,13 @@
#define DRIVER_AUTHOR "Stephen Hemminger <sthemmin at microsoft.com>"
#define DRIVER_DESC "Generic UIO driver for VMBus devices"
+#define RING_SIZE_MIN 64
+#define RING_SIZE_MAX 512
+
+static unsigned int ring_size = 128;
+module_param(ring_size, uint, 0444);
+MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
+
/*
* List of resources to be mapped to user space
* can be extended up to MAX_UIO_MAPS(5) items
@@ -49,8 +56,6 @@ enum hv_uio_map {
MON_PAGE_MAP,
};
-#define HV_RING_SIZE 512
-
struct hv_uio_private_data {
struct uio_info info;
struct hv_device *device;
@@ -102,8 +107,8 @@ hv_uio_probe(struct hv_device *dev,
if (!pdata)
return -ENOMEM;
- ret = vmbus_open(dev->channel, HV_RING_SIZE * PAGE_SIZE,
- HV_RING_SIZE * PAGE_SIZE, NULL, 0,
+ ret = vmbus_open(dev->channel, ring_size * PAGE_SIZE,
+ ring_size * PAGE_SIZE, NULL, 0,
hv_uio_channel_cb, pdata);
if (ret)
goto fail;
@@ -183,6 +188,18 @@ static struct hv_driver hv_uio_drv = {
static int __init
hyperv_module_init(void)
{
+ if (ring_size < RING_SIZE_MIN) {
+ ring_size = RING_SIZE_MIN;
+ pr_info("Increased ring_size to %u (min allowed)\n",
+ ring_size);
+ }
+
+ if (ring_size > RING_SIZE_MAX) {
+ ring_size = RING_SIZE_MAX;
+ pr_info("Decreased ring_size to %u (max allowed)\n",
+ ring_size);
+ }
+
return vmbus_driver_register(&hv_uio_drv);
}
--
2.15.1
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