[Zion][Denali] Move to MSI for AHCI devices.

This will allow us to properly do interrupts for XHCI devices in the
future.

Also move PCI device header parsing to a shared library.

Get rid of the old irq register format which supplied an irq number and
instead pass the appropriate irq number back out to the caller.

rust/lib/mammoth/src/bindings.rs

@@ -258,6 +258,7 @@ pub const kZionPortSend: u64 = 81;
 pub const kZionPortRecv: u64 = 82;
 pub const kZionPortPoll: u64 = 83;
 pub const kZionIrqRegister: u64 = 88;
+pub const kZionMsiIrqRegister: u64 = 89;
 pub const kZionEndpointCreate: u64 = 96;
 pub const kZionEndpointSend: u64 = 97;
 pub const kZionEndpointRecv: u64 = 98;
@@ -478,6 +479,12 @@ pub struct ZIrqRegisterReq {
 }
 #[repr(C)]
 #[derive(Debug, Copy, Clone)]
+pub struct ZMsiIrqRegisterReq {
+    pub irq_num: *mut u64,
+    pub port_cap: *mut z_cap_t,
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
 pub struct ZEndpointCreateReq {
     pub endpoint_cap: *mut z_cap_t,
 }

rust/lib/mammoth/src/mem.rs

@@ -120,6 +120,12 @@ impl<T> AsRef<T> for MemoryRegion {
     }
 }
 
+impl<T> AsMut<T> for MemoryRegion {
+    fn as_mut(&mut self) -> &mut T {
+        unsafe { (self.virt_addr as *mut T).as_mut().unwrap() }
+    }
+}
+
 impl Drop for MemoryRegion {
     fn drop(&mut self) {
         // FIXME: We shouldn't have to do this manual adjustment.

rust/lib/mammoth/src/syscall.rs

@@ -310,16 +310,17 @@ pub fn port_poll(
     Ok((num_bytes, num_caps))
 }
 
-pub fn register_irq(irq_num: u64) -> Result<Capability, ZError> {
+pub fn register_msi_irq() -> Result<(Capability, u64), ZError> {
+    let mut irq_num: u64 = 0;
     let mut port_cap: z_cap_t = 0;
     syscall(
-        zion::kZionIrqRegister,
-        &zion::ZIrqRegisterReq {
-            irq_num,
+        zion::kZionMsiIrqRegister,
+        &zion::ZMsiIrqRegisterReq {
+            irq_num: &mut irq_num as *mut u64,
             port_cap: &mut port_cap,
         },
     )?;
-    Ok(Capability::take(port_cap))
+    Ok((Capability::take(port_cap), irq_num))
 }
 
 pub fn endpoint_create() -> Result<Capability, ZError> {