virtio_mmio: re-order all virtio mmio devices before inserting into fdt

When we insert virtio mmio devices into fdt, we should add it in order,
from low to high.
For now, they were iterated and inserted in anogstic order.
To avoid that, we re-store them in Vec for sorting out lately in right
order.

Signed-off-by: Penny Zheng <[email protected]>
Signed-off-by: Haibo Xu <[email protected]>

Author: Pennyzct

arch/src/aarch64/fdt.rs

@@ -441,7 +441,7 @@ fn create_psci_node(fdt: &mut Vec<u8>) -> Result<()> {
 
 fn create_virtio_node<T: DeviceInfoForFDT + Clone + Debug>(
     fdt: &mut Vec<u8>,
-    dev_info: T,
+    dev_info: &T,
 ) -> Result<()> {
     let device_reg_prop = generate_prop64(&[dev_info.addr(), dev_info.length()]);
     let irq = generate_prop32(&[GIC_FDT_IRQ_TYPE_SPI, dev_info.irq(), IRQ_TYPE_EDGE_RISING]);
@@ -458,7 +458,7 @@ fn create_virtio_node<T: DeviceInfoForFDT + Clone + Debug>(
 
 fn create_serial_node<T: DeviceInfoForFDT + Clone + Debug>(
     fdt: &mut Vec<u8>,
-    dev_info: T,
+    dev_info: &T,
 ) -> Result<()> {
     let serial_reg_prop = generate_prop64(&[dev_info.addr(), dev_info.length()]);
     let irq = generate_prop32(&[GIC_FDT_IRQ_TYPE_SPI, dev_info.irq(), IRQ_TYPE_EDGE_RISING]);
@@ -476,7 +476,7 @@ fn create_serial_node<T: DeviceInfoForFDT + Clone + Debug>(
 
 fn create_rtc_node<T: DeviceInfoForFDT + Clone + Debug>(
     fdt: &mut Vec<u8>,
-    dev_info: T,
+    dev_info: &T,
 ) -> Result<()> {
     let compatible = b"arm,pl031\0arm,primecell\0";
     let rtc_reg_prop = generate_prop64(&[dev_info.addr(), dev_info.length()]);
@@ -496,35 +496,23 @@ fn create_devices_node<T: DeviceInfoForFDT + Clone + Debug>(
     fdt: &mut Vec<u8>,
     dev_info: &HashMap<(DeviceType, String), T>,
 ) -> Result<()> {
-    // We are trying to detect the root block device. We know
-    // that if a root block device is attached, it will be the one with the lowest bus address.
-
-    // As per doc, `None` will be returned only if the iterator
-    // is empty. That cannot happen, since on aarch64 the RTC device is
-    // always appended to the hashmap of devices.
-    let ((first_device_type, first_device_id), first_device_info) = dev_info
-        .iter()
-        .min_by(|&(_, ref a), &(_, ref b)| a.addr().cmp(&b.addr()))
-        .expect("Device Information cannot be empty");
-
-    // We check that the device with the lowest bus address is indeed a virtio device.
-    // At this point, it does not matter whether we are dealing with network or block since
-    // the create_virtio_node function is agnostic of that.
-    if let DeviceType::Virtio(_) = first_device_type {
-        create_virtio_node(fdt, first_device_info.clone())?;
-    }
+    // Create one temp Vec to store all virtio devices
+    let mut ordered_virtio_device: Vec<&T> = Vec::new();
 
     for ((device_type, device_id), info) in dev_info {
         match device_type {
-            DeviceType::RTC => create_rtc_node(fdt, info.clone())?,
-            DeviceType::Serial => create_serial_node(fdt, info.clone())?,
+            DeviceType::RTC => create_rtc_node(fdt, info)?,
+            DeviceType::Serial => create_serial_node(fdt, info)?,
             DeviceType::Virtio(_) => {
-                // We already appended the first virtio device.
-                if (device_type, device_id) != (&first_device_type, &first_device_id) {
-                    create_virtio_node(fdt, info.clone())?;
-                }
+                ordered_virtio_device.push(info);
             }
-        };
+        }
+    }
+
+    // Sort out virtio devices by address from low to high and insert them into fdt table.
+    ordered_virtio_device.sort_by(|a, b| a.addr().cmp(&b.addr()));
+    for ordered_device_info in ordered_virtio_device.drain(..) {
+        create_virtio_node(fdt, ordered_device_info)?;
     }
 
     Ok(())