gpu: nova-core: gsp: Retrieve GSP static info to gather GPU information

After GSP initialization is complete, retrieve the static configuration
information from GSP-RM. This information includes GPU name, capabilities,
memory configuration, and other properties. On some GPU variants, it is
also required to do this for initialization to complete.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
Co-developed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
[acourbot@nvidia.com: properly abstract the command's bindings, add
relevant methods, make str_from_null_terminated return an Option, fix
size of GPU name array.]
Co-developed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251114195552.739371-14-joelagnelf@nvidia.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/gpu/nova-core/util.rs b/drivers/gpu/nova-core/util.rs
new file mode 100644
index 000000000000..4b503249a3ef
--- /dev/null
+++ b/drivers/gpu/nova-core/util.rs
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/// Converts a null-terminated byte slice to a string, or `None` if the array does not
+/// contains any null byte or contains invalid characters.
+///
+/// Contrary to [`kernel::str::CStr::from_bytes_with_nul`], the null byte can be anywhere in the
+/// slice, and not only in the last position.
+pub(crate) fn str_from_null_terminated(bytes: &[u8]) -> Option<&str> {
+    use kernel::str::CStr;
+
+    bytes
+        .iter()
+        .position(|&b| b == 0)
+        .and_then(|null_pos| CStr::from_bytes_with_nul(&bytes[..=null_pos]).ok())
+        .and_then(|cstr| cstr.to_str().ok())
+}