[PATCH 3/7] rust: pci: allow drivers to manage DMA ownership

[Zhi Wang]

From: Danilo Krummrich <dakr@xxxxxxxxxx>

VFIO manages DMA ownership through the userspace IOMMU interface. Its
PCI variant drivers must opt out of the driver's default DMA domain.

Add Driver::DRIVER_MANAGED_DMA and pass it to the PCI core. Existing
Rust PCI drivers keep the default setting.

Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
Signed-off-by: Zhi Wang <zhiw@xxxxxxxxxx>
---
 rust/kernel/pci.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 10864ffda4ea..a156927e23d5 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -108,6 +108,7 @@ unsafe fn register(
             (*pdrv.get()).probe = Some(Self::probe_callback);
             (*pdrv.get()).remove = Some(Self::remove_callback);
             (*pdrv.get()).id_table = T::ID_TABLE.as_ptr();
+            (*pdrv.get()).driver_managed_dma = T::DRIVER_MANAGED_DMA;
             #[cfg(CONFIG_PCI_IOV)]
             if T::HAS_SRIOV_ENABLE {
                 (*pdrv.get()).sriov_configure = Some(Self::sriov_configure_callback);
@@ -345,6 +346,9 @@ pub trait Driver {
     /// The table of device ids supported by the driver.
     const ID_TABLE: IdTable<Self::IdInfo>;
 
+    /// Whether the driver manages DMA ownership instead of using the default DMA domain.
+    const DRIVER_MANAGED_DMA: bool = false;
+
     /// PCI driver probe.
     ///
     /// Called when a new pci device is added or discovered. Implementers should
-- 
2.53.0