[x/azure][PATCH 02/17] uio_hv_generic: create send and receive buffers

[Marcelo Henrique Cerri]

From: Stephen Hemminger <stephen at networkplumber.org>

BugLink: http://bugs.launchpad.net/bugs/1812123

Map in receive and send buffers for networking in UIO device.
These buffers are special and need to be setup by kernel
API's; userspace can not do it.

Signed-off-by: Stephen Hemminger <sthemmin at microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit e7d214642a19b8e0e7ecda39184c2ab98ba4801f)
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 Documentation/driver-api/uio-howto.rst |  2 +
 drivers/uio/uio_hv_generic.c           | 71 +++++++++++++++++++++++++-
 2 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/Documentation/driver-api/uio-howto.rst b/Documentation/driver-api/uio-howto.rst
index 733672ff702d..3d582634d1f5 100644
--- a/Documentation/driver-api/uio-howto.rst
+++ b/Documentation/driver-api/uio-howto.rst
@@ -701,6 +701,8 @@ The vmbus device regions are mapped into uio device resources:
     0) Channel ring buffers: guest to host and host to guest
     1) Guest to host interrupt signalling pages
     2) Guest to host monitor page
+    3) Network receive buffer region
+    4) Network send buffer region
 
 Further information
 ===================
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index fe5cdda80b2c..dee96330bd53 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -37,6 +37,10 @@
 #define DRIVER_AUTHOR	"Stephen Hemminger <sthemmin at microsoft.com>"
 #define DRIVER_DESC	"Generic UIO driver for VMBus devices"
 
+#define HV_RING_SIZE	 512	/* pages */
+#define SEND_BUFFER_SIZE (15 * 1024 * 1024)
+#define RECV_BUFFER_SIZE (15 * 1024 * 1024)
+
 /*
  * List of resources to be mapped to user space
  * can be extended up to MAX_UIO_MAPS(5) items
@@ -45,13 +49,21 @@ enum hv_uio_map {
 	TXRX_RING_MAP = 0,
 	INT_PAGE_MAP,
 	MON_PAGE_MAP,
+	RECV_BUF_MAP,
+	SEND_BUF_MAP
 };
 
-#define HV_RING_SIZE	512
-
 struct hv_uio_private_data {
 	struct uio_info info;
 	struct hv_device *device;
+
+	void	*recv_buf;
+	u32	recv_gpadl;
+	char	recv_name[32];	/* "recv_4294967295" */
+
+	void	*send_buf;
+	u32	send_gpadl;
+	char	send_name[32];
 };
 
 static int
@@ -107,6 +119,19 @@ static void hv_uio_channel_cb(void *context)
 	uio_event_notify(&pdata->info);
 }
 
+
+static void
+hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata)
+{
+	if (pdata->send_gpadl)
+		vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl);
+	vfree(pdata->send_buf);
+
+	if (pdata->recv_gpadl)
+		vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl);
+	vfree(pdata->recv_buf);
+}
+
 static int
 hv_uio_probe(struct hv_device *dev,
 	     const struct hv_vmbus_device_id *dev_id)
@@ -161,6 +186,46 @@ hv_uio_probe(struct hv_device *dev,
 	pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE;
 	pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL;
 
+	pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE);
+	if (pdata->recv_buf == NULL) {
+		ret = -ENOMEM;
+		goto fail_close;
+	}
+
+	ret = vmbus_establish_gpadl(dev->channel, pdata->recv_buf,
+				    RECV_BUFFER_SIZE, &pdata->recv_gpadl);
+	if (ret)
+		goto fail_close;
+
+	/* put Global Physical Address Label in name */
+	snprintf(pdata->recv_name, sizeof(pdata->recv_name),
+		 "recv:%u", pdata->recv_gpadl);
+	pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
+	pdata->info.mem[RECV_BUF_MAP].addr
+		= (phys_addr_t)pdata->recv_buf;
+	pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE;
+	pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
+
+
+	pdata->send_buf = vzalloc(SEND_BUFFER_SIZE);
+	if (pdata->send_buf == NULL) {
+		ret = -ENOMEM;
+		goto fail_close;
+	}
+
+	ret = vmbus_establish_gpadl(dev->channel, pdata->send_buf,
+				    SEND_BUFFER_SIZE, &pdata->send_gpadl);
+	if (ret)
+		goto fail_close;
+
+	snprintf(pdata->send_name, sizeof(pdata->send_name),
+		 "send:%u", pdata->send_gpadl);
+	pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
+	pdata->info.mem[SEND_BUF_MAP].addr
+		= (phys_addr_t)pdata->send_buf;
+	pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE;
+	pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
+
 	pdata->info.priv = pdata;
 	pdata->device = dev;
 
@@ -175,6 +240,7 @@ hv_uio_probe(struct hv_device *dev,
 	return 0;
 
 fail_close:
+	hv_uio_cleanup(dev, pdata);
 	vmbus_close(dev->channel);
 fail:
 	kfree(pdata);
@@ -191,6 +257,7 @@ hv_uio_remove(struct hv_device *dev)
 		return 0;
 
 	uio_unregister_device(&pdata->info);
+	hv_uio_cleanup(dev, pdata);
 	hv_set_drvdata(dev, NULL);
 	vmbus_close(dev->channel);
 	kfree(pdata);
-- 
2.20.1