[PATCH v5 03/13] gpu: nova-core: falcon: Move mbox functionalities into helper

[Joel Fernandes <joelagnelf@nvidia.com>]

Move falcon reading/writing to mbox functionality into helper so we can
use it from the sequencer resume flow.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
 drivers/gpu/nova-core/falcon.rs | 51 +++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/nova-core/falcon.rs b/drivers/gpu/nova-core/falcon.rs
index 30af7fc2814d..5c9f054a0f42 100644
--- a/drivers/gpu/nova-core/falcon.rs
+++ b/drivers/gpu/nova-core/falcon.rs
@@ -578,19 +578,13 @@ pub(crate) fn start(&self, bar: &Bar0) -> Result<()> {
         Ok(())
     }
 
-    /// Start running the loaded firmware.
-    ///
-    /// `mbox0` and `mbox1` are optional parameters to write into the `MBOX0` and `MBOX1` registers
-    /// prior to running.
-    ///
-    /// Wait up to two seconds for the firmware to complete, and return its exit status read from
-    /// the `MBOX0` and `MBOX1` registers.
-    pub(crate) fn boot(
+    /// Writes values to the mailbox registers if provided.
+    pub(crate) fn write_mailboxes(
         &self,
         bar: &Bar0,
         mbox0: Option<u32>,
         mbox1: Option<u32>,
-    ) -> Result<(u32, u32)> {
+    ) -> Result<()> {
         if let Some(mbox0) = mbox0 {
             regs::NV_PFALCON_FALCON_MAILBOX0::default()
                 .set_value(mbox0)
@@ -602,18 +596,45 @@ pub(crate) fn boot(
                 .set_value(mbox1)
                 .write(bar, &E::ID);
         }
+        Ok(())
+    }
 
-        self.start(bar)?;
-        self.wait_till_halted(bar)?;
+    /// Reads the value from `mbox0` register.
+    pub(crate) fn read_mailbox0(&self, bar: &Bar0) -> Result<u32> {
+        Ok(regs::NV_PFALCON_FALCON_MAILBOX0::read(bar, &E::ID).value())
+    }
 
-        let (mbox0, mbox1) = (
-            regs::NV_PFALCON_FALCON_MAILBOX0::read(bar, &E::ID).value(),
-            regs::NV_PFALCON_FALCON_MAILBOX1::read(bar, &E::ID).value(),
-        );
+    /// Reads the value from `mbox1` register.
+    pub(crate) fn read_mailbox1(&self, bar: &Bar0) -> Result<u32> {
+        Ok(regs::NV_PFALCON_FALCON_MAILBOX1::read(bar, &E::ID).value())
+    }
 
+    /// Reads values from both mailbox registers.
+    pub(crate) fn read_mailboxes(&self, bar: &Bar0) -> Result<(u32, u32)> {
+        let mbox0 = self.read_mailbox0(bar)?;
+        let mbox1 = self.read_mailbox1(bar)?;
         Ok((mbox0, mbox1))
     }
 
+    /// Start running the loaded firmware.
+    ///
+    /// `mbox0` and `mbox1` are optional parameters to write into the `MBOX0` and `MBOX1` registers
+    /// prior to running.
+    ///
+    /// Wait up to two seconds for the firmware to complete, and return its exit status read from
+    /// the `MBOX0` and `MBOX1` registers.
+    pub(crate) fn boot(
+        &self,
+        bar: &Bar0,
+        mbox0: Option<u32>,
+        mbox1: Option<u32>,
+    ) -> Result<(u32, u32)> {
+        self.write_mailboxes(bar, mbox0, mbox1)?;
+        self.start(bar)?;
+        self.wait_till_halted(bar)?;
+        self.read_mailboxes(bar)
+    }
+
     /// Returns the fused version of the signature to use in order to run a HS firmware on this
     /// falcon instance. `engine_id_mask` and `ucode_id` are obtained from the firmware header.
     pub(crate) fn signature_reg_fuse_version(
-- 
2.34.1