Implement read_many for denali.

rust/sys/denali/src/ahci/controller.rs

@@ -285,6 +285,16 @@ impl Command {
         })
     }
 
+    pub fn read_manual(lba: u64, lba_count: u16, paddr: u64) -> Self {
+        Self {
+            command: SataCommand::DmaReadExt,
+            lba,
+            sector_cnt: lba_count,
+            paddr: paddr,
+            memory_region: None,
+        }
+    }
+
     pub fn release_mem_cap(&mut self) -> u64 {
         self.memory_region.take().unwrap().release()
     }

rust/sys/denali/src/denali_server.rs

@@ -1,5 +1,5 @@
 use alloc::sync::Arc;
-use mammoth::zion::ZError;
+use mammoth::{syscall, zion::ZError};
 
 use crate::{
     ahci::{AhciController, Command},
@@ -32,7 +32,30 @@ impl AsyncDenaliServerHandler for DenaliServerImpl {
         })
     }
 
-    async fn read_many(&self, _req: ReadManyRequest) -> Result<ReadResponse, ZError> {
-        Err(ZError::UNIMPLEMENTED)
+    async fn read_many(&self, req: ReadManyRequest) -> Result<ReadResponse, ZError> {
+        let total_sector_cnt = req.blocks.iter().map(|b| b.size).sum();
+
+        // FIXME: Don't hardcode this.
+        let sector_size = 512;
+
+        let (mem_cap, mut paddr) =
+            syscall::memory_object_contiguous_physical(sector_size * total_sector_cnt)?;
+
+        for block in req.blocks {
+            let command = Command::read_manual(block.lba, block.size as u16, paddr);
+
+            // TODO: We should actually be able to read all of these in parallel.
+            self.ahci_controller
+                .issue_command(req.device_id as usize, &command)
+                .await;
+
+            paddr += block.size * sector_size;
+        }
+
+        Ok(ReadResponse {
+            device_id: req.device_id,
+            size: total_sector_cnt,
+            memory: mem_cap.release(),
+        })
     }
 }