Keep Gsp::new() from getting too cluttered, by factoring out the
selection of .fwsignature* items. This will continue to grow as we add
GPUs.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 drivers/gpu/nova-core/firmware/gsp.rs | 43 ++++++++++++++-------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/nova-core/firmware/gsp.rs b/drivers/gpu/nova-core/firmware/gsp.rs
index 547f46b6655b..86ed4d650d05 100644
--- a/drivers/gpu/nova-core/firmware/gsp.rs
+++ b/drivers/gpu/nova-core/firmware/gsp.rs
@@ -151,39 +151,42 @@ pub(crate) struct GspFirmware {
 }
 
 impl GspFirmware {
-    /// Loads the GSP firmware binaries, map them into `dev`'s address-space, and creates the page
-    /// tables expected by the GSP bootloader to load it.
-    pub(crate) fn new<'a, 'b>(
-        dev: &'a device::Device<device::Bound>,
-        chipset: Chipset,
-        ver: &'b str,
-    ) -> Result<impl PinInit<Self, Error> + 'a> {
-        let fw = super::request_firmware(dev, chipset, "gsp", ver)?;
-
-        let fw_section = elf::elf64_section(fw.data(), ".fwimage").ok_or(EINVAL)?;
-
-        let sigs_section = match chipset.arch() {
-            Architecture::Ampere => ".fwsignature_ga10x",
-            Architecture::Hopper => ".fwsignature_gh10x",
-            Architecture::Ada => ".fwsignature_ad10x",
+    fn get_gsp_sigs_section(chipset: Chipset) -> Result<&'static str> {
+        match chipset.arch() {
+            Architecture::Ampere => Ok(".fwsignature_ga10x"),
+            Architecture::Hopper => Ok(".fwsignature_gh10x"),
+            Architecture::Ada => Ok(".fwsignature_ad10x"),
             Architecture::Blackwell => {
                 // Distinguish between GB10x and GB20x series
                 match chipset {
                     // GB10x series: GB100, GB102
-                    Chipset::GB100 | Chipset::GB102 => ".fwsignature_gb10x",
+                    Chipset::GB100 | Chipset::GB102 => Ok(".fwsignature_gb10x"),
                     // GB20x series: GB202, GB203, GB205, GB206, GB207
                     Chipset::GB202
                     | Chipset::GB203
                     | Chipset::GB205
                     | Chipset::GB206
-                    | Chipset::GB207 => ".fwsignature_gb20x",
+                    | Chipset::GB207 => Ok(".fwsignature_gb20x"),
                     // Non-Blackwell chipsets, which can't happen here, but Rust doesn't know that.
-                    _ => return Err(ENOTSUPP),
+                    _ => Err(ENOTSUPP),
                 }
             }
+            _ => Err(ENOTSUPP),
+        }
+    }
 
-            _ => return Err(ENOTSUPP),
-        };
+    /// Loads the GSP firmware binaries, map them into `dev`'s address-space, and creates the page
+    /// tables expected by the GSP bootloader to load it.
+    pub(crate) fn new<'a, 'b>(
+        dev: &'a device::Device<device::Bound>,
+        chipset: Chipset,
+        ver: &'b str,
+    ) -> Result<impl PinInit<Self, Error> + 'a> {
+        let fw = super::request_firmware(dev, chipset, "gsp", ver)?;
+
+        let fw_section = elf::elf64_section(fw.data(), ".fwimage").ok_or(EINVAL)?;
+
+        let sigs_section = Self::get_gsp_sigs_section(chipset)?;
         let signatures = elf::elf64_section(fw.data(), sigs_section)
             .ok_or(EINVAL)
             .and_then(|data| DmaObject::from_data(dev, data))?;
-- 
2.52.0