[PATCH v7 06/31] gpu: nova-core: Hopper/Blackwell: skip GFW boot waiting

[John Hubbard]

Hopper and Blackwell GPUs use FSP-based secure boot and do not require
waiting for GFW_BOOT completion. Skip this step for these architectures.

Move the GFW_BOOT policy into a dedicated GPU HAL in gpu/hal.rs. This
keeps the decision out of gpu.rs while avoiding unrelated subsystems
such as fb. Pre-Hopper families still wait for GFW_BOOT completion,
while Hopper and later use the FSP Chain of Trust boot path instead.

Cc: Danilo Krummrich <dakr@xxxxxxxxxx>
Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
---
 drivers/gpu/nova-core/gpu.rs     | 14 ++++++---
 drivers/gpu/nova-core/gpu/hal.rs | 54 ++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 4 deletions(-)
 create mode 100644 drivers/gpu/nova-core/gpu/hal.rs

diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 9e140463603b..93f861ba20f3 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -23,6 +23,8 @@
     regs,
 };
 
+mod hal;
+
 macro_rules! define_chipset {
     ({ $($variant:ident = $value:expr),* $(,)* }) =>
     {
@@ -309,13 +311,17 @@ pub(crate) fn new<'a>(
         spec: Spec,
     ) -> impl PinInit<Self, Error> + 'a {
         let chipset = spec.chipset();
+        let hal = hal::gpu_hal(chipset);
 
         try_pin_init!(Self {
-            // We must wait for GFW_BOOT completion before doing any significant setup
-            // on the GPU.
             _: {
-                gfw::wait_gfw_boot_completion(bar)
-                    .inspect_err(|_| dev_err!(pdev, "GFW boot did not complete\n"))?;
+                // GFW_BOOT is the "GPU firmware boot complete" signal for the
+                // legacy devinit/FWSEC path. Pre-Hopper GPUs must wait for it
+                // before most GPU initialization. Hopper and later boot via FSP.
+                if hal.needs_gfw_boot() {
+                    gfw::wait_gfw_boot_completion(bar)
+                        .inspect_err(|_| dev_err!(pdev, "GFW boot did not complete\n"))?;
+                }
             },
 
             sysmem_flush: SysmemFlush::register(pdev.as_ref(), bar, chipset)?,
diff --git a/drivers/gpu/nova-core/gpu/hal.rs b/drivers/gpu/nova-core/gpu/hal.rs
new file mode 100644
index 000000000000..859c5e5fa21f
--- /dev/null
+++ b/drivers/gpu/nova-core/gpu/hal.rs
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use crate::gpu::{
+    Architecture,
+    Chipset, //
+};
+
+pub(crate) trait GpuHal {
+    /// Returns whether this hardware family still requires waiting for GFW_BOOT.
+    fn needs_gfw_boot(&self) -> bool;
+}
+
+struct Tu102;
+struct Ga100;
+struct Ga102;
+struct Fsp;
+
+impl GpuHal for Tu102 {
+    fn needs_gfw_boot(&self) -> bool {
+        true
+    }
+}
+
+impl GpuHal for Ga100 {
+    fn needs_gfw_boot(&self) -> bool {
+        true
+    }
+}
+
+impl GpuHal for Ga102 {
+    fn needs_gfw_boot(&self) -> bool {
+        true
+    }
+}
+
+impl GpuHal for Fsp {
+    fn needs_gfw_boot(&self) -> bool {
+        false
+    }
+}
+
+const TU102: Tu102 = Tu102;
+const GA100: Ga100 = Ga100;
+const GA102: Ga102 = Ga102;
+const FSP: Fsp = Fsp;
+
+pub(super) fn gpu_hal(chipset: Chipset) -> &'static dyn GpuHal {
+    match chipset.arch() {
+        Architecture::Turing => &TU102,
+        Architecture::Ampere if chipset == Chipset::GA100 => &GA100,
+        Architecture::Ampere | Architecture::Ada => &GA102,
+        Architecture::Hopper | Architecture::Blackwell => &FSP,
+    }
+}
-- 
2.53.0