[PATCH v3 02/11] gpu: nova-core: move GSP boot code out of `Gpu` constructor

[Alexandre Courbot <acourbot@nvidia.com>]

Right now the GSP boot code is very incomplete and limited to running
FRTS, so having it in `Gpu::new` is not a big constraint.

However, this will change as we add more steps of the GSP boot process,
some of which are rather cumbersome to perform on a
partially-constructed GPU instance.

Relatedly, booting the GSP typically happens only once in the GPU reset
cycle. Most of the data created to complete this step (notably firmware
loaded from user-space) is needed only temporary and can be discarded
once the GSP is booted; it then makes all the more sense to store these
as local variables of a dedicated method, instead of inside the `Gpu`
structure where they as kept as long as the GPU is bound, using dozens
of megabytes of host memory.

Thus, introduce a `start_gsp` method on the `Gpu` struct, which is
called by `probe` after the GPU is instantiated and will return the
running GSP instance, once the code completing its boot is integrated.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/driver.rs | 10 +++++++++-
 drivers/gpu/nova-core/gpu.rs    | 41 ++++++++++++++++++++++++++++++-----------
 2 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
index 274989ea1fb4a5e3e6678a08920ddc76d2809ab2..1062014c0a488e959379f009c2e8029ffaa1e2f8 100644
--- a/drivers/gpu/nova-core/driver.rs
+++ b/drivers/gpu/nova-core/driver.rs
@@ -6,6 +6,8 @@
 
 #[pin_data]
 pub(crate) struct NovaCore {
+    // Placeholder for the real `Gsp` object once it is built.
+    pub(crate) gsp: (),
     #[pin]
     pub(crate) gpu: Gpu,
     _reg: auxiliary::Registration,
@@ -40,8 +42,14 @@ fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self
         )?;
 
         let this = KBox::pin_init(
-            try_pin_init!(Self {
+            try_pin_init!(&this in Self {
                 gpu <- Gpu::new(pdev, bar)?,
+                gsp <- {
+                    // SAFETY: `this.gpu` is initialized to a valid value.
+                    let gpu = unsafe { &(*this.as_ptr()).gpu };
+
+                    gpu.start_gsp(pdev)?
+                },
                 _reg: auxiliary::Registration::new(
                     pdev.as_ref(),
                     c_str!("nova-drm"),
diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 4d0f759610ec6eb8a716c039a2e67859410da17c..8343276e52e6a87a8ff1aff9fc484e00d4b57417 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -172,6 +172,8 @@ pub(crate) struct Gpu {
     /// System memory page required for flushing all pending GPU-side memory writes done through
     /// PCIE into system memory, via sysmembar (A GPU-initiated HW memory-barrier operation).
     sysmem_flush: SysmemFlush,
+    gsp_falcon: Falcon<Gsp>,
+    sec2_falcon: Falcon<Sec2>,
 }
 
 #[pinned_drop]
@@ -190,8 +192,8 @@ impl Gpu {
     /// TODO: this needs to be moved into a larger type responsible for booting the whole GSP
     /// (`GspBooter`?).
     fn run_fwsec_frts(
+        &self,
         dev: &device::Device<device::Bound>,
-        falcon: &Falcon<Gsp>,
         bar: &Bar0,
         bios: &Vbios,
         fb_layout: &FbLayout,
@@ -208,7 +210,7 @@ fn run_fwsec_frts(
 
         let fwsec_frts = FwsecFirmware::new(
             dev,
-            falcon,
+            &self.gsp_falcon,
             bar,
             bios,
             FwsecCommand::Frts {
@@ -218,7 +220,7 @@ fn run_fwsec_frts(
         )?;
 
         // Run FWSEC-FRTS to create the WPR2 region.
-        fwsec_frts.run(dev, falcon, bar)?;
+        fwsec_frts.run(dev, &self.gsp_falcon, bar)?;
 
         // SCRATCH_E contains the error code for FWSEC-FRTS.
         let frts_status = regs::NV_PBUS_SW_SCRATCH_0E_FRTS_ERR::read(bar).frts_err_code();
@@ -263,6 +265,28 @@ fn run_fwsec_frts(
         }
     }
 
+    /// Attempt to start the GSP.
+    ///
+    /// This is a GPU-dependent and complex procedure that involves loading firmware files from
+    /// user-space, patching them with signatures, and building firmware-specific intricate data
+    /// structures that the GSP will use at runtime.
+    ///
+    /// Upon return, the GSP is up and running, and its runtime object given as return value.
+    pub(crate) fn start_gsp(&self, pdev: &pci::Device<device::Bound>) -> Result<()> {
+        let dev = pdev.as_ref();
+
+        let bar = self.bar.access(dev)?;
+
+        let bios = Vbios::new(dev, bar)?;
+
+        let fb_layout = FbLayout::new(self.spec.chipset, bar)?;
+        dev_dbg!(dev, "{:#x?}\n", fb_layout);
+
+        self.run_fwsec_frts(dev, bar, &bios, &fb_layout)?;
+
+        Ok(())
+    }
+
     pub(crate) fn new(
         pdev: &pci::Device<device::Bound>,
         devres_bar: Arc<Devres<Bar0>>,
@@ -293,20 +317,15 @@ pub(crate) fn new(
         )?;
         gsp_falcon.clear_swgen0_intr(bar);
 
-        let _sec2_falcon = Falcon::<Sec2>::new(pdev.as_ref(), spec.chipset, bar, true)?;
-
-        let fb_layout = FbLayout::new(spec.chipset, bar)?;
-        dev_dbg!(pdev.as_ref(), "{:#x?}\n", fb_layout);
-
-        let bios = Vbios::new(pdev.as_ref(), bar)?;
-
-        Self::run_fwsec_frts(pdev.as_ref(), &gsp_falcon, bar, &bios, &fb_layout)?;
+        let sec2_falcon = Falcon::<Sec2>::new(pdev.as_ref(), spec.chipset, bar, true)?;
 
         Ok(pin_init!(Self {
             spec,
             bar: devres_bar,
             fw,
             sysmem_flush,
+            gsp_falcon,
+            sec2_falcon,
         }))
     }
 }

-- 
2.51.0