gpu: nova-core: add falcon register definitions and base code

Booting the GSP on Ampere requires an intricate dance between the GSP
and SEC2 falcons, where the GSP starts by running the FWSEC firmware to
create the WPR2 region , and then SEC2 loads the actual RISC-V firmware
into the GSP.

Add the common Falcon code and HAL for Ampere GPUs, and instantiate the
GSP and SEC2 Falcons that will be required to perform that dance and
boot the GSP.

Thanks to Ben Skeggs for pointing out an important bug in the memory
scrubbing code that could lead to a race condition and ultimately a
failure to boot the GSP!

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://lore.kernel.org/r/20250619-nova-frts-v6-15-ecf41ef99252@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 119 insertions, 0 deletions

diff --git a/drivers/gpu/nova-core/falcon/hal/ga102.rs b/drivers/gpu/nova-core/falcon/hal/ga102.rs
new file mode 100644
index 000000000000..0a4e5e7adf8c
--- /dev/null
+++ b/drivers/gpu/nova-core/falcon/hal/ga102.rs
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use core::marker::PhantomData;
+use core::time::Duration;
+
+use kernel::device;
+use kernel::prelude::*;
+
+use crate::driver::Bar0;
+use crate::falcon::{
+    Falcon, FalconBromParams, FalconEngine, FalconModSelAlgo, PeregrineCoreSelect,
+};
+use crate::regs;
+use crate::util;
+
+use super::FalconHal;
+
+fn select_core_ga102<E: FalconEngine>(bar: &Bar0) -> Result {
+    let bcr_ctrl = regs::NV_PRISCV_RISCV_BCR_CTRL::read(bar, E::BASE);
+    if bcr_ctrl.core_select() != PeregrineCoreSelect::Falcon {
+        regs::NV_PRISCV_RISCV_BCR_CTRL::default()
+            .set_core_select(PeregrineCoreSelect::Falcon)
+            .write(bar, E::BASE);
+
+        // TIMEOUT: falcon core should take less than 10ms to report being enabled.
+        util::wait_on(Duration::from_millis(10), || {
+            let r = regs::NV_PRISCV_RISCV_BCR_CTRL::read(bar, E::BASE);
+            if r.valid() {
+                Some(())
+            } else {
+                None
+            }
+        })?;
+    }
+
+    Ok(())
+}
+
+fn signature_reg_fuse_version_ga102(
+    dev: &device::Device,
+    bar: &Bar0,
+    engine_id_mask: u16,
+    ucode_id: u8,
+) -> Result<u32> {
+    // TODO: The ucode fuse versions are contained in the FUSE_OPT_FPF_<ENGINE>_UCODE<X>_VERSION
+    // registers, which are an array. Our register definition macros do not allow us to manage them
+    // properly, so we need to hardcode their addresses for now. Clean this up once we support
+    // register arrays.
+
+    // Each engine has 16 ucode version registers numbered from 1 to 16.
+    if ucode_id == 0 || ucode_id > 16 {
+        dev_err!(dev, "invalid ucode id {:#x}", ucode_id);
+        return Err(EINVAL);
+    }
+
+    // Base address of the FUSE registers array corresponding to the engine.
+    let reg_fuse_base = if engine_id_mask & 0x0001 != 0 {
+        regs::NV_FUSE_OPT_FPF_SEC2_UCODE1_VERSION::OFFSET
+    } else if engine_id_mask & 0x0004 != 0 {
+        regs::NV_FUSE_OPT_FPF_NVDEC_UCODE1_VERSION::OFFSET
+    } else if engine_id_mask & 0x0400 != 0 {
+        regs::NV_FUSE_OPT_FPF_GSP_UCODE1_VERSION::OFFSET
+    } else {
+        dev_err!(dev, "unexpected engine_id_mask {:#x}", engine_id_mask);
+        return Err(EINVAL);
+    };
+
+    // Read `reg_fuse_base[ucode_id - 1]`.
+    let reg_fuse_version =
+        bar.read32(reg_fuse_base + ((ucode_id - 1) as usize * core::mem::size_of::<u32>()));
+
+    // TODO: replace with `last_set_bit` once it lands.
+    Ok(u32::BITS - reg_fuse_version.leading_zeros())
+}
+
+fn program_brom_ga102<E: FalconEngine>(bar: &Bar0, params: &FalconBromParams) -> Result {
+    regs::NV_PFALCON2_FALCON_BROM_PARAADDR::default()
+        .set_value(params.pkc_data_offset)
+        .write(bar, E::BASE);
+    regs::NV_PFALCON2_FALCON_BROM_ENGIDMASK::default()
+        .set_value(params.engine_id_mask as u32)
+        .write(bar, E::BASE);
+    regs::NV_PFALCON2_FALCON_BROM_CURR_UCODE_ID::default()
+        .set_ucode_id(params.ucode_id)
+        .write(bar, E::BASE);
+    regs::NV_PFALCON2_FALCON_MOD_SEL::default()
+        .set_algo(FalconModSelAlgo::Rsa3k)
+        .write(bar, E::BASE);
+
+    Ok(())
+}
+
+pub(super) struct Ga102<E: FalconEngine>(PhantomData<E>);
+
+impl<E: FalconEngine> Ga102<E> {
+    pub(super) fn new() -> Self {
+        Self(PhantomData)
+    }
+}
+
+impl<E: FalconEngine> FalconHal<E> for Ga102<E> {
+    fn select_core(&self, _falcon: &Falcon<E>, bar: &Bar0) -> Result {
+        select_core_ga102::<E>(bar)
+    }
+
+    fn signature_reg_fuse_version(
+        &self,
+        falcon: &Falcon<E>,
+        bar: &Bar0,
+        engine_id_mask: u16,
+        ucode_id: u8,
+    ) -> Result<u32> {
+        signature_reg_fuse_version_ga102(&falcon.dev, bar, engine_id_mask, ucode_id)
+    }
+
+    fn program_brom(&self, _falcon: &Falcon<E>, bar: &Bar0, params: &FalconBromParams) -> Result {
+        program_brom_ga102::<E>(bar, params)
+    }
+}