[PATCH v6 22/34] gpu: nova-core: Hopper/Blackwell: add FSP secure boot completion waiting

[John Hubbard <jhubbard@nvidia.com>]

Add the FSP (Firmware System Processor) module for Hopper/Blackwell GPUs.
These architectures use a simplified firmware boot sequence:

    FMC --> FSP --> GSP, with no SEC2 involvement.

This commit adds the ability to wait for FSP secure boot completion by
polling the I2CS thermal scratch register until FSP signals success.

Cc: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 drivers/gpu/nova-core/fsp.rs       | 141 +++++++++++++++++++++++++++++
 drivers/gpu/nova-core/nova_core.rs |   1 +
 drivers/gpu/nova-core/regs.rs      |  12 +--
 3 files changed, 148 insertions(+), 6 deletions(-)
 create mode 100644 drivers/gpu/nova-core/fsp.rs

diff --git a/drivers/gpu/nova-core/fsp.rs b/drivers/gpu/nova-core/fsp.rs
new file mode 100644
index 000000000000..d464ad325881
--- /dev/null
+++ b/drivers/gpu/nova-core/fsp.rs
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! FSP (Firmware System Processor) interface for Hopper/Blackwell GPUs.
+//!
+//! Hopper/Blackwell use a simplified firmware boot sequence: FMC --> FSP --> GSP.
+//! Unlike Turing/Ampere/Ada, there is NO SEC2 (Security Engine 2) usage.
+//! FSP handles secure boot directly using FMC firmware + Chain of Trust.
+
+use kernel::{
+    device,
+    io::poll::read_poll_timeout,
+    prelude::*,
+    time::Delta,
+    transmute::{
+        AsBytes,
+        FromBytes, //
+    },
+};
+
+use crate::regs;
+
+/// FSP secure boot completion timeout in milliseconds.
+const FSP_SECURE_BOOT_TIMEOUT_MS: i64 = 4000;
+
+/// GSP FMC initialization parameters.
+#[repr(C)]
+#[derive(Debug, Clone, Copy, Default)]
+struct GspFmcInitParams {
+    /// CC initialization "registry keys".
+    regkeys: u32,
+}
+
+// SAFETY: GspFmcInitParams is a simple C struct with only primitive types.
+unsafe impl AsBytes for GspFmcInitParams {}
+// SAFETY: All bit patterns are valid for the primitive fields.
+unsafe impl FromBytes for GspFmcInitParams {}
+
+/// GSP ACR (Authenticated Code RAM) boot parameters.
+#[repr(C)]
+#[derive(Debug, Clone, Copy, Default)]
+struct GspAcrBootGspRmParams {
+    /// Physical memory aperture through which gspRmDescPa is accessed.
+    target: u32,
+    /// Size in bytes of the GSP-RM descriptor structure.
+    gsp_rm_desc_size: u32,
+    /// Physical offset in the target aperture of the GSP-RM descriptor structure.
+    gsp_rm_desc_offset: u64,
+    /// Physical offset in FB to set the start of the WPR containing GSP-RM.
+    wpr_carveout_offset: u64,
+    /// Size in bytes of the WPR containing GSP-RM.
+    wpr_carveout_size: u32,
+    /// Whether to boot GSP-RM or GSP-Proxy through ACR.
+    b_is_gsp_rm_boot: u32,
+}
+
+// SAFETY: GspAcrBootGspRmParams is a simple C struct with only primitive types.
+unsafe impl AsBytes for GspAcrBootGspRmParams {}
+// SAFETY: All bit patterns are valid for the primitive fields.
+unsafe impl FromBytes for GspAcrBootGspRmParams {}
+
+/// GSP RM boot parameters.
+#[repr(C)]
+#[derive(Debug, Clone, Copy, Default)]
+struct GspRmParams {
+    /// Physical memory aperture through which bootArgsOffset is accessed.
+    target: u32,
+    /// Physical offset in the memory aperture that will be passed to GSP-RM.
+    boot_args_offset: u64,
+}
+
+// SAFETY: GspRmParams is a simple C struct with only primitive types.
+unsafe impl AsBytes for GspRmParams {}
+// SAFETY: All bit patterns are valid for the primitive fields.
+unsafe impl FromBytes for GspRmParams {}
+
+/// GSP SPDM (Security Protocol and Data Model) parameters.
+#[repr(C)]
+#[derive(Debug, Clone, Copy, Default)]
+struct GspSpdmParams {
+    /// Physical memory aperture through which all addresses are accessed.
+    target: u32,
+    /// Physical offset in the memory aperture where SPDM payload buffer is stored.
+    payload_buffer_offset: u64,
+    /// Size of the above payload buffer.
+    payload_buffer_size: u32,
+}
+
+// SAFETY: GspSpdmParams is a simple C struct with only primitive types.
+unsafe impl AsBytes for GspSpdmParams {}
+// SAFETY: All bit patterns are valid for the primitive fields.
+unsafe impl FromBytes for GspSpdmParams {}
+
+/// Complete GSP FMC boot parameters passed to FSP.
+#[repr(C)]
+#[derive(Debug, Clone, Copy, Default)]
+pub(crate) struct GspFmcBootParams {
+    init_params: GspFmcInitParams,
+    boot_gsp_rm_params: GspAcrBootGspRmParams,
+    gsp_rm_params: GspRmParams,
+    gsp_spdm_params: GspSpdmParams,
+}
+
+// SAFETY: GspFmcBootParams is composed of C structs with only primitive types.
+unsafe impl AsBytes for GspFmcBootParams {}
+// SAFETY: All bit patterns are valid for the primitive fields.
+unsafe impl FromBytes for GspFmcBootParams {}
+
+/// FSP interface for Hopper/Blackwell GPUs.
+pub(crate) struct Fsp;
+
+impl Fsp {
+    /// Wait for FSP secure boot completion.
+    ///
+    /// Polls the thermal scratch register until FSP signals boot completion
+    /// or timeout occurs.
+    #[expect(dead_code)]
+    pub(crate) fn wait_secure_boot(
+        dev: &device::Device<device::Bound>,
+        bar: &crate::driver::Bar0,
+        arch: crate::gpu::Architecture,
+    ) -> Result {
+        debug_assert!(
+            regs::read_fsp_boot_complete_status(bar, arch).is_some(),
+            "wait_secure_boot called on non-FSP architecture"
+        );
+
+        let timeout = Delta::from_millis(FSP_SECURE_BOOT_TIMEOUT_MS);
+
+        read_poll_timeout(
+            || regs::read_fsp_boot_complete_status(bar, arch).ok_or(ENOTSUPP),
+            |&status| status == regs::FSP_BOOT_COMPLETE_SUCCESS,
+            Delta::from_millis(10),
+            timeout,
+        )
+        .map_err(|_| {
+            dev_err!(dev, "FSP secure boot completion timeout\n");
+            ETIMEDOUT
+        })
+        .map(|_| ())
+    }
+}
diff --git a/drivers/gpu/nova-core/nova_core.rs b/drivers/gpu/nova-core/nova_core.rs
index 3bd9b1dd0264..bdbe7136f873 100644
--- a/drivers/gpu/nova-core/nova_core.rs
+++ b/drivers/gpu/nova-core/nova_core.rs
@@ -10,6 +10,7 @@
 mod falcon;
 mod fb;
 mod firmware;
+mod fsp;
 mod gfw;
 mod gpu;
 mod gsp;
diff --git a/drivers/gpu/nova-core/regs.rs b/drivers/gpu/nova-core/regs.rs
index 7c6311cd37bb..e2ad70d32ff9 100644
--- a/drivers/gpu/nova-core/regs.rs
+++ b/drivers/gpu/nova-core/regs.rs
@@ -508,17 +508,17 @@ pub(crate) fn fsp_thermal_scratch_reg_addr(arch: Architecture) -> Result<usize>
 }
 
 /// FSP writes this value to indicate successful boot completion.
-#[expect(unused)]
 pub(crate) const FSP_BOOT_COMPLETE_SUCCESS: u32 = 0xff;
 
-// Helper function to read FSP boot completion status from the correct register
-#[expect(unused)]
+/// Read FSP boot completion status from the architecture-specific thermal scratch register.
+///
+/// Returns `None` if the architecture does not have an FSP.
 pub(crate) fn read_fsp_boot_complete_status(
     bar: &crate::driver::Bar0,
     arch: Architecture,
-) -> Result<u32> {
-    let addr = fsp_thermal_scratch_reg_addr(arch)?;
-    Ok(bar.read32(addr))
+) -> Option<u32> {
+    let addr = fsp_thermal_scratch_reg_addr(arch).ok()?;
+    Some(bar.read32(addr))
 }
 
 // The modules below provide registers that are not identical on all supported chips. They should
-- 
2.53.0