[PATCH 4/6] gpu: nova-core: add FbHal::frts_size() for GA100 support

[Timur Tabi <ttabi@nvidia.com>]

Introduce FbHal method frts_size() to return the size of the FRTS
window.  GA100 is a special case in that there is no FRTS, and so
the size must be set to 0.

Note that we cannot use supports_display() to determine the FRTS
size because there are other GPUs (e.g. GA102GL) that have display
disabled (and so supports_display() returns False), but the FRTS
window size still needs to be 1MB.

Signed-off-by: Timur Tabi <ttabi@nvidia.com>
---
 drivers/gpu/nova-core/fb.rs           | 6 +++---
 drivers/gpu/nova-core/fb/hal.rs       | 3 +++
 drivers/gpu/nova-core/fb/hal/ga100.rs | 5 +++++
 drivers/gpu/nova-core/fb/hal/ga102.rs | 8 +++++++-
 drivers/gpu/nova-core/fb/hal/tu102.rs | 8 +++++++-
 5 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/nova-core/fb.rs b/drivers/gpu/nova-core/fb.rs
index bdd5eed760e1..abffc21427a1 100644
--- a/drivers/gpu/nova-core/fb.rs
+++ b/drivers/gpu/nova-core/fb.rs
@@ -216,10 +216,10 @@ pub(crate) fn new(chipset: Chipset, bar: &Bar0, gsp_fw: &GspFirmware) -> Result<
 
         let frts = {
             const FRTS_DOWN_ALIGN: Alignment = Alignment::new::<SZ_128K>();
-            const FRTS_SIZE: u64 = usize_as_u64(SZ_1M);
-            let frts_base = vga_workspace.start.align_down(FRTS_DOWN_ALIGN) - FRTS_SIZE;
+            let frts_size: u64 = hal.frts_size();
+            let frts_base = vga_workspace.start.align_down(FRTS_DOWN_ALIGN) - frts_size;
 
-            FbRange(frts_base..frts_base + FRTS_SIZE)
+            FbRange(frts_base..frts_base + frts_size)
         };
 
         let boot = {
diff --git a/drivers/gpu/nova-core/fb/hal.rs b/drivers/gpu/nova-core/fb/hal.rs
index aba0abd8ee00..1c01a6cbed65 100644
--- a/drivers/gpu/nova-core/fb/hal.rs
+++ b/drivers/gpu/nova-core/fb/hal.rs
@@ -25,6 +25,9 @@ pub(crate) trait FbHal {
 
     /// Returns the VRAM size, in bytes.
     fn vidmem_size(&self, bar: &Bar0) -> u64;
+
+    /// Returns the FRTS size, in bytes.
+    fn frts_size(&self) -> u64;
 }
 
 /// Returns the HAL corresponding to `chipset`.
diff --git a/drivers/gpu/nova-core/fb/hal/ga100.rs b/drivers/gpu/nova-core/fb/hal/ga100.rs
index 1c03783cddef..0e7d91fbd130 100644
--- a/drivers/gpu/nova-core/fb/hal/ga100.rs
+++ b/drivers/gpu/nova-core/fb/hal/ga100.rs
@@ -66,6 +66,11 @@ fn supports_display(&self, bar: &Bar0) -> bool {
     fn vidmem_size(&self, bar: &Bar0) -> u64 {
         super::tu102::vidmem_size_gp102(bar)
     }
+
+    // GA100 is a special case where it has no FRTS.
+    fn frts_size(&self) -> u64 {
+        0
+    }
 }
 
 const GA100: Ga100 = Ga100;
diff --git a/drivers/gpu/nova-core/fb/hal/ga102.rs b/drivers/gpu/nova-core/fb/hal/ga102.rs
index 4b9f0f74d0e7..167d38e34370 100644
--- a/drivers/gpu/nova-core/fb/hal/ga102.rs
+++ b/drivers/gpu/nova-core/fb/hal/ga102.rs
@@ -2,12 +2,14 @@
 
 use kernel::{
     io::Io,
-    prelude::*, //
+    prelude::*,
+    sizes::*, //
 };
 
 use crate::{
     driver::Bar0,
     fb::hal::FbHal,
+    num::*,
     regs, //
 };
 
@@ -35,6 +37,10 @@ fn supports_display(&self, bar: &Bar0) -> bool {
     fn vidmem_size(&self, bar: &Bar0) -> u64 {
         vidmem_size_ga102(bar)
     }
+
+    fn frts_size(&self) -> u64 {
+        usize_as_u64(SZ_1M)
+    }
 }
 
 const GA102: Ga102 = Ga102;
diff --git a/drivers/gpu/nova-core/fb/hal/tu102.rs b/drivers/gpu/nova-core/fb/hal/tu102.rs
index 281bb796e198..3482469f9cf1 100644
--- a/drivers/gpu/nova-core/fb/hal/tu102.rs
+++ b/drivers/gpu/nova-core/fb/hal/tu102.rs
@@ -2,12 +2,14 @@
 
 use kernel::{
     io::Io,
-    prelude::*, //
+    prelude::*,
+    sizes::*, //
 };
 
 use crate::{
     driver::Bar0,
     fb::hal::FbHal,
+    num::*,
     regs, //
 };
 
@@ -56,6 +58,10 @@ fn supports_display(&self, bar: &Bar0) -> bool {
     fn vidmem_size(&self, bar: &Bar0) -> u64 {
         vidmem_size_gp102(bar)
     }
+
+    fn frts_size(&self) -> u64 {
+        usize_as_u64(SZ_1M)
+    }
 }
 
 const TU102: Tu102 = Tu102;
-- 
2.53.0