add nvm format and completely clearing namespace, use reference inste…

…ad of copy in completion polling

src/cmd.rs

@@ -174,4 +174,46 @@ impl NvmeCommand {
             cdw15: 0,
         }
     }
+
+    pub(crate) fn format_nvm(c_id: u16, ns_id: u32) -> Self {
+        Self {
+            opcode: 0x80,
+            flags: 0,
+            c_id,
+            ns_id,
+            _rsvd: 0,
+            md_ptr: 0,
+            d_ptr: [0, 0],
+            cdw10: 1 << 9,
+            // TODO: dealloc and prinfo bits
+            cdw11: 0,
+            cdw12: 0,
+            cdw13: 0,
+            cdw14: 0,
+            cdw15: 0,
+
+        }
+
+    }
+
+    // not supported by samsung
+    pub fn write_zeroes(c_id: u16, ns_id: u32, slba: u64, nlb: u16, deac: bool) -> Self {
+        Self {
+            opcode: 8,
+            flags: 0,
+            c_id,
+            ns_id,
+            _rsvd: 0,
+            md_ptr: 0,
+            d_ptr: [0, 0],
+            cdw10: slba as u32,
+            // TODO: dealloc and prinfo bits
+            cdw11: (slba >> 32) as u32,
+            cdw12: ((deac as u32) << 25) | nlb as u32,
+            cdw13: 0,
+            cdw14: 0,
+            cdw15: 0,
+        }
+
+    }
 }

src/nvme.rs

@@ -156,9 +156,8 @@ impl NvmeQueuePair {
         unsafe {
             std::ptr::write_volatile(self.comp_queue.doorbell as *mut u32, tail as u32);
         }
-
-        let status = c_entry.status >> 1;
         self.sub_queue.head = c_entry.sq_head as usize;
+        let status = c_entry.status >> 1;
         if status != 0 {
             eprintln!(
                 "Status: 0x{:x}, Status Code 0x{:x}, Status Code Type: 0x{:x}",
@@ -177,6 +176,7 @@ impl NvmeQueuePair {
             unsafe {
                 std::ptr::write_volatile(self.comp_queue.doorbell as *mut u32, tail as u32);
             }
+            self.sub_queue.head = c_entry.sq_head as usize;
             let status = c_entry.status >> 1;
             if status != 0 {
                 eprintln!(
@@ -187,7 +187,6 @@ impl NvmeQueuePair {
                 );
                 eprintln!("{:?}", c_entry);
             }
-            self.sub_queue.head = c_entry.sq_head as usize;
             return Some(());
         }
         None
@@ -731,6 +730,19 @@ impl NvmeDevice {
         Ok(entry)
     }
 
+    pub fn clear_namespace(
+        &mut self,
+        ns_id: Option<u32>
+    ) {
+        let ns_id = if let Some(ns_id) = ns_id {
+            assert!(self.namespaces.contains_key(&ns_id));
+            ns_id
+        } else {
+            0xFFFF_FFFF
+        };
+        self.submit_and_complete_admin(| c_id, _ | { NvmeCommand::format_nvm(c_id, ns_id) } );
+    }
+
     /// Sets Queue `qid` Tail Doorbell to `val`
     fn write_reg_idx(&self, reg: NvmeArrayRegs, qid: u16, val: u32) {
         match reg {

src/queues.rs

@@ -98,16 +98,17 @@ impl NvmeCompQueue {
         })
     }
 
+    #[inline(always)]
     pub fn complete(&mut self) -> Option<(usize, NvmeCompletion, usize)> {
-        let entry: NvmeCompletion = self.commands[self.head];
+        let entry = &self.commands[self.head];
 
         if ((entry.status & 1) == 1) == self.phase {
             let prev = self.head;
             self.head = (self.head + 1) % self.len;
             if self.head == 0 {
                 self.phase = !self.phase;
             }
-            Some((self.head, entry, prev))
+            Some((self.head, entry.clone(), prev))
         } else {
             None
         }