[PATCH 05/10] uio_hv_generic: make ring size configurable

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Allow setting size of ring buffer for host communication via
module parameter.

Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
---
 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

_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel



[Index of Archives]     [Linux Driver Backports]     [DMA Engine]     [Linux GPIO]     [Linux SPI]     [Video for Linux]     [Linux USB Devel]     [Linux Coverity]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux