uio_hv_generic: Add a check for HV_NIC for send, receive buffers setup

Receive and send buffer allocation was originally introduced to support
DPDK's networking use case. These buffer sizes were further increased to
meet DPDK performance requirements. However, these large buffers are
unnecessary for any other UIO use cases.
Restrict the allocation of receive and send buffers only for HV_NIC device
type, saving 47 MB of memory per device.

While at it, fix some of the syntax related issues in the touched code
which are reported by "--strict" option of checkpatch.

Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250102145243.2088-1-namjain@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250102145243.2088-1-namjain@linux.microsoft.com>

Author: Naman Jain

drivers/uio/uio_hv_generic.c

@@ -296,51 +296,51 @@ 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_free_ring;
+	if (channel->device_id == HV_NIC) {
+		pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE);
+		if (!pdata->recv_buf) {
+			ret = -ENOMEM;
+			goto fail_free_ring;
+		}
+
+		ret = vmbus_establish_gpadl(channel, pdata->recv_buf,
+					    RECV_BUFFER_SIZE, &pdata->recv_gpadl);
+		if (ret) {
+			if (!pdata->recv_gpadl.decrypted)
+				vfree(pdata->recv_buf);
+			goto fail_close;
+		}
+
+		/* put Global Physical Address Label in name */
+		snprintf(pdata->recv_name, sizeof(pdata->recv_name),
+			 "recv:%u", pdata->recv_gpadl.gpadl_handle);
+		pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
+		pdata->info.mem[RECV_BUF_MAP].addr = (uintptr_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) {
+			ret = -ENOMEM;
+			goto fail_close;
+		}
+
+		ret = vmbus_establish_gpadl(channel, pdata->send_buf,
+					    SEND_BUFFER_SIZE, &pdata->send_gpadl);
+		if (ret) {
+			if (!pdata->send_gpadl.decrypted)
+				vfree(pdata->send_buf);
+			goto fail_close;
+		}
+
+		snprintf(pdata->send_name, sizeof(pdata->send_name),
+			 "send:%u", pdata->send_gpadl.gpadl_handle);
+		pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
+		pdata->info.mem[SEND_BUF_MAP].addr = (uintptr_t)pdata->send_buf;
+		pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE;
+		pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
 	}
 
-	ret = vmbus_establish_gpadl(channel, pdata->recv_buf,
-				    RECV_BUFFER_SIZE, &pdata->recv_gpadl);
-	if (ret) {
-		if (!pdata->recv_gpadl.decrypted)
-			vfree(pdata->recv_buf);
-		goto fail_close;
-	}
-
-	/* put Global Physical Address Label in name */
-	snprintf(pdata->recv_name, sizeof(pdata->recv_name),
-		 "recv:%u", pdata->recv_gpadl.gpadl_handle);
-	pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
-	pdata->info.mem[RECV_BUF_MAP].addr
-		= (uintptr_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(channel, pdata->send_buf,
-				    SEND_BUFFER_SIZE, &pdata->send_gpadl);
-	if (ret) {
-		if (!pdata->send_gpadl.decrypted)
-			vfree(pdata->send_buf);
-		goto fail_close;
-	}
-
-	snprintf(pdata->send_name, sizeof(pdata->send_name),
-		 "send:%u", pdata->send_gpadl.gpadl_handle);
-	pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
-	pdata->info.mem[SEND_BUF_MAP].addr
-		= (uintptr_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;