Upon reset, the GPU executes the GFW_BOOT firmware in order to
initialize its base parameters such as clocks. The driver must ensure
that this step is completed before using the hardware.

Signed-off-by: Alexandre Courbot <acour...@nvidia.com>
---
 drivers/gpu/nova-core/devinit.rs   | 40 ++++++++++++++++++++++++++++++++++++++
 drivers/gpu/nova-core/driver.rs    |  2 +-
 drivers/gpu/nova-core/gpu.rs       |  5 +++++
 drivers/gpu/nova-core/nova_core.rs |  1 +
 drivers/gpu/nova-core/regs.rs      | 11 +++++++++++
 5 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/nova-core/devinit.rs b/drivers/gpu/nova-core/devinit.rs
new file mode 100644
index 
0000000000000000000000000000000000000000..ee5685aff845aa97d6b0fbe9528df9a7ba274b2c
--- /dev/null
+++ b/drivers/gpu/nova-core/devinit.rs
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Methods for device initialization.
+
+use kernel::bindings;
+use kernel::devres::Devres;
+use kernel::prelude::*;
+
+use crate::driver::Bar0;
+use crate::regs;
+
+/// Wait for devinit FW completion.
+///
+/// Upon reset, the GPU runs some firmware code to setup its core parameters. 
Most of the GPU is
+/// considered unusable until this step is completed, so it must be waited on 
very early during
+/// driver initialization.
+pub(crate) fn wait_gfw_boot_completion(bar: &Devres<Bar0>) -> Result<()> {
+    let mut timeout = 2000;
+
+    loop {
+        let gfw_booted = with_bar!(
+            bar,
+            |b| regs::Pgc6AonSecureScratchGroup05PrivLevelMask::read(b)
+                .read_protection_level0_enabled()
+                && (regs::Pgc6AonSecureScratchGroup05::read(b).value() & 0xff) 
== 0xff
+        )?;
+
+        if gfw_booted {
+            return Ok(());
+        }
+
+        if timeout == 0 {
+            return Err(ETIMEDOUT);
+        }
+        timeout -= 1;
+
+        // SAFETY: msleep should be safe to call with any parameter.
+        unsafe { bindings::msleep(2) };
+    }
+}
diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
index 
a08fb6599267a960f0e07b6efd0e3b6cdc296aa4..752ba4b0fcfe8d835d366570bb2f807840a196da
 100644
--- a/drivers/gpu/nova-core/driver.rs
+++ b/drivers/gpu/nova-core/driver.rs
@@ -10,7 +10,7 @@ pub(crate) struct NovaCore {
     pub(crate) gpu: Gpu,
 }
 
-const BAR0_SIZE: usize = 8;
+const BAR0_SIZE: usize = 0x1000000;
 pub(crate) type Bar0 = pci::Bar<BAR0_SIZE>;
 
 kernel::pci_device_table!(
diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 
866c5992b9eb27735975bb4948e522bc01fadaa2..1f7799692a0ab042f2540e01414f5ca347ae9ecc
 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -2,6 +2,7 @@
 
 use kernel::{device, devres::Devres, error::code::*, pci, prelude::*};
 
+use crate::devinit;
 use crate::driver::Bar0;
 use crate::firmware::Firmware;
 use crate::regs;
@@ -168,6 +169,10 @@ pub(crate) fn new(
             spec.revision
         );
 
+        // We must wait for GFW_BOOT completion before doing any significant 
setup on the GPU.
+        devinit::wait_gfw_boot_completion(&bar)
+            .inspect_err(|_| pr_err!("GFW boot did not complete"))?;
+
         Ok(pin_init!(Self { spec, bar, fw }))
     }
 }
diff --git a/drivers/gpu/nova-core/nova_core.rs 
b/drivers/gpu/nova-core/nova_core.rs
index 
0eecd612e34efc046dad852e6239de6ffa5fdd62..878161e060f54da7738c656f6098936a62dcaa93
 100644
--- a/drivers/gpu/nova-core/nova_core.rs
+++ b/drivers/gpu/nova-core/nova_core.rs
@@ -20,6 +20,7 @@ macro_rules! with_bar {
     }
 }
 
+mod devinit;
 mod driver;
 mod firmware;
 mod gpu;
diff --git a/drivers/gpu/nova-core/regs.rs b/drivers/gpu/nova-core/regs.rs
index 
e315a3011660df7f18c0a3e0582b5845545b36e2..fd7096f0ddd4af90114dd1119d9715d2cd3aa2ac
 100644
--- a/drivers/gpu/nova-core/regs.rs
+++ b/drivers/gpu/nova-core/regs.rs
@@ -13,3 +13,14 @@
     7:4     major_rev => as u8, "major revision of the chip";
     28:20   chipset => try_into Chipset, "chipset model"
 );
+
+/* GC6 */
+
+register!(Pgc6AonSecureScratchGroup05PrivLevelMask@0x00118128;
+    0:0     read_protection_level0_enabled => as_bit bool
+);
+
+/* TODO: This is an array of registers. */
+register!(Pgc6AonSecureScratchGroup05@0x00118234;
+    31:0    value => as u32
+);

-- 
2.49.0

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