[PATCH v2 1/3] gpu: nova-core: Add function to query WPR2 range

[Antonin Malzieu Ridolfi via B4 Relay <devnull+dev.nanonej.com@kernel.org>]

From: Antonin Malzieu Ridolfi <dev@nanonej.com>

Create new function abstracting WPR2 region range query.
Refactor gsp hal tu102 to query the WPR2 region range using this new
function.

Suggested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Antonin Malzieu Ridolfi <dev@nanonej.com>
---
 drivers/gpu/nova-core/fb.rs            | 14 +++++++++
 drivers/gpu/nova-core/gsp/hal/tu102.rs | 54 +++++++++++++++-------------------
 2 files changed, 38 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/nova-core/fb.rs b/drivers/gpu/nova-core/fb.rs
index 365db7abf7db..8934efc5f436 100644
--- a/drivers/gpu/nova-core/fb.rs
+++ b/drivers/gpu/nova-core/fb.rs
@@ -289,3 +289,17 @@ pub(crate) fn new(
         })
     }
 }
+
+/// Reads the WPR2 memory region registers and returns the range if set.
+/// Returns `None` if the WPR2 region is not set.
+pub(crate) fn wpr2_range(bar: Bar0<'_>) -> Option<Range<u64>> {
+    let wpr2_hi = bar.read(crate::regs::NV_PFB_PRI_MMU_WPR2_ADDR_HI);
+
+    if !wpr2_hi.is_wpr2_set() {
+        return None;
+    }
+
+    let wpr2_lo = bar.read(crate::regs::NV_PFB_PRI_MMU_WPR2_ADDR_LO);
+
+    Some(wpr2_lo.lower_bound()..wpr2_hi.higher_bound())
+}
diff --git a/drivers/gpu/nova-core/gsp/hal/tu102.rs b/drivers/gpu/nova-core/gsp/hal/tu102.rs
index 648657e248da..03861add8e20 100644
--- a/drivers/gpu/nova-core/gsp/hal/tu102.rs
+++ b/drivers/gpu/nova-core/gsp/hal/tu102.rs
@@ -17,7 +17,10 @@
         sec2::Sec2,
         Falcon, //
     },
-    fb::FbLayout,
+    fb::{
+        wpr2_range,
+        FbLayout, //
+    },
     firmware::{
         booter::{
             BooterFirmware,
@@ -90,9 +93,8 @@ fn run(&self, ctx: &mut GspBootContext<'_, '_>) -> Result {
             .inspect_err(|e| dev_err!(dev, "FWSEC-SB failed to run: {:?}\n", e));
 
         // Remove WPR2 region if set.
-        let wpr2_hi = bar.read(regs::NV_PFB_PRI_MMU_WPR2_ADDR_HI);
         let booter_unloader_res = (|| {
-            if !wpr2_hi.is_wpr2_set() {
+            if wpr2_range(bar).is_none() {
                 return Ok(());
             }
 
@@ -110,8 +112,7 @@ fn run(&self, ctx: &mut GspBootContext<'_, '_>) -> Result {
             }
 
             // Confirm that the WPR2 region has been removed.
-            let wpr2_hi = bar.read(regs::NV_PFB_PRI_MMU_WPR2_ADDR_HI);
-            if wpr2_hi.is_wpr2_set() {
+            if wpr2_range(bar).is_some() {
                 dev_err!(
                     dev,
                     "WPR2 region still set after Booter Unloader returned\n"
@@ -146,7 +147,7 @@ fn run_fwsec_frts(
     ) -> Result {
         // Check that the WPR2 region does not already exist - if it does, we cannot run
         // FWSEC-FRTS until the GPU is reset.
-        if bar.read(regs::NV_PFB_PRI_MMU_WPR2_ADDR_HI).higher_bound() != 0 {
+        if wpr2_range(bar).is_some() {
             dev_err!(
                 dev,
                 "WPR2 region already exists - GPU needs to be reset to proceed\n"
@@ -189,34 +190,27 @@ fn run_fwsec_frts(
         }
 
         // Check that the WPR2 region has been created as we requested.
-        let (wpr2_lo, wpr2_hi) = (
-            bar.read(regs::NV_PFB_PRI_MMU_WPR2_ADDR_LO).lower_bound(),
-            bar.read(regs::NV_PFB_PRI_MMU_WPR2_ADDR_HI).higher_bound(),
-        );
-
-        match (wpr2_lo, wpr2_hi) {
-            (_, 0) => {
-                dev_err!(dev, "WPR2 region not created after running FWSEC-FRTS\n");
+        let Some(wpr2_range) = wpr2_range(bar) else {
+            dev_err!(dev, "WPR2 region not created after running FWSEC-FRTS\n");
 
-                Err(EIO)
-            }
-            (wpr2_lo, _) if wpr2_lo != fb_layout.frts.start => {
-                dev_err!(
-                    dev,
-                    "WPR2 region created at unexpected address {:#x}; expected {:#x}\n",
-                    wpr2_lo,
-                    fb_layout.frts.start,
-                );
+            return Err(EIO);
+        };
 
-                Err(EIO)
-            }
-            (wpr2_lo, wpr2_hi) => {
-                dev_dbg!(dev, "WPR2: {:#x}-{:#x}\n", wpr2_lo, wpr2_hi);
-                dev_dbg!(dev, "GPU instance built\n");
+        if wpr2_range.start != fb_layout.frts.start {
+            dev_err!(
+                dev,
+                "WPR2 region created at unexpected address {:#x}; expected {:#x}\n",
+                wpr2_range.start,
+                fb_layout.frts.start,
+            );
 
-                Ok(())
-            }
+            return Err(EIO);
         }
+
+        dev_dbg!(dev, "WPR2: {:#x}-{:#x}\n", wpr2_range.start, wpr2_range.end);
+        dev_dbg!(dev, "GPU instance built\n");
+
+        Ok(())
     }
 
     /// Load and prepare the resources required to properly reset the GSP after it has been stopped.

-- 
2.55.0