Commit 76544ef6 authored by Alexandre Courbot's avatar Alexandre Courbot
Browse files

gpu: nova-core: replace wait_on with kernel equivalents 



wait_on was a temporary helper function waiting for a kernel crate
equivalent.

Now that read_poll_timeout and fsleep are available, use them and remove
wait_on.

Acked-by: default avatarDanilo Krummrich <dakr@kernel.org>
Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251020-nova_wait_on-v1-1-2eb87fb38d14@nvidia.com>
parent c58f00b4

Documentation/gpu/nova/core/todo.rst

+0 −11
Original line number Diff line number Diff line
@@ -153,17 +153,6 @@ A `num` core kernel module is being designed to provide these operations. 
| Complexity: Intermediate

| Contact: Alexandre Courbot



Delay / Sleep abstractions [DLAY]

---------------------------------



Rust abstractions for the kernel's delay() and sleep() functions.



FUJITA Tomonori plans to work on abstractions for read_poll_timeout_atomic()

(and friends) [1].



| Complexity: Beginner

| Link: https://lore.kernel.org/netdev/20250228.080550.354359820929821928.fujita.tomonori@gmail.com/ [1]



IRQ abstractions

----------------

drivers/gpu/nova-core/falcon.rs

+28 −34
Original line number Diff line number Diff line
@@ -6,8 +6,10 @@ 
use hal::FalconHal;

use kernel::device;

use kernel::dma::DmaAddress;

use kernel::io::poll::read_poll_timeout;

use kernel::prelude::*;

use kernel::sync::aref::ARef;

use kernel::time::delay::fsleep;

use kernel::time::Delta;



use crate::dma::DmaObject;
@@ -15,7 +17,6 @@ 
use crate::gpu::Chipset;

use crate::regs;

use crate::regs::macros::RegisterBase;

use crate::util;



pub(crate) mod gsp;

mod hal;
@@ -372,13 +373,13 @@ pub(crate) fn new(dev: &device::Device, chipset: Chipset) -> Result<Self> { 
    /// Wait for memory scrubbing to complete.

    fn reset_wait_mem_scrubbing(&self, bar: &Bar0) -> Result {

        // TIMEOUT: memory scrubbing should complete in less than 20ms.

        util::wait_on(Delta::from_millis(20), || {

            if regs::NV_PFALCON_FALCON_HWCFG2::read(bar, &E::ID).mem_scrubbing_done() {

                Some(())

            } else {

                None

            }

        })

        read_poll_timeout(

            || Ok(regs::NV_PFALCON_FALCON_HWCFG2::read(bar, &E::ID)),

            |r| r.mem_scrubbing_done(),

            Delta::ZERO,

            Delta::from_millis(20),

        )

        .map(|_| ())

    }



    /// Reset the falcon engine.
@@ -387,20 +388,17 @@ fn reset_eng(&self, bar: &Bar0) -> Result { 


        // According to OpenRM's `kflcnPreResetWait_GA102` documentation, HW sometimes does not set

        // RESET_READY so a non-failing timeout is used.

        let _ = util::wait_on(Delta::from_micros(150), || {

            let r = regs::NV_PFALCON_FALCON_HWCFG2::read(bar, &E::ID);

            if r.reset_ready() {

                Some(())

            } else {

                None

            }

        });

        let _ = read_poll_timeout(

            || Ok(regs::NV_PFALCON_FALCON_HWCFG2::read(bar, &E::ID)),

            |r| r.reset_ready(),

            Delta::ZERO,

            Delta::from_micros(150),

        );



        regs::NV_PFALCON_FALCON_ENGINE::update(bar, &E::ID, |v| v.set_reset(true));



        // TODO[DLAY]: replace with udelay() or equivalent once available.

        // TIMEOUT: falcon engine should not take more than 10us to reset.

        let _: Result = util::wait_on(Delta::from_micros(10), || None);

        fsleep(Delta::from_micros(10));



        regs::NV_PFALCON_FALCON_ENGINE::update(bar, &E::ID, |v| v.set_reset(false));
@@ -504,14 +502,12 @@ fn dma_wr<F: FalconFirmware<Target = E>>( 
            // Wait for the transfer to complete.

            // TIMEOUT: arbitrarily large value, no DMA transfer to the falcon's small memories

            // should ever take that long.

            util::wait_on(Delta::from_secs(2), || {

                let r = regs::NV_PFALCON_FALCON_DMATRFCMD::read(bar, &E::ID);

                if r.idle() {

                    Some(())

                } else {

                    None

                }

            })?;

            read_poll_timeout(

                || Ok(regs::NV_PFALCON_FALCON_DMATRFCMD::read(bar, &E::ID)),

                |r| r.idle(),

                Delta::ZERO,

                Delta::from_secs(2),

            )?;

        }



        Ok(())
@@ -574,14 +570,12 @@ pub(crate) fn boot( 
        }



        // TIMEOUT: arbitrarily large value, firmwares should complete in less than 2 seconds.

        util::wait_on(Delta::from_secs(2), || {

            let r = regs::NV_PFALCON_FALCON_CPUCTL::read(bar, &E::ID);

            if r.halted() {

                Some(())

            } else {

                None

            }

        })?;

        read_poll_timeout(

            || Ok(regs::NV_PFALCON_FALCON_CPUCTL::read(bar, &E::ID)),

            |r| r.halted(),

            Delta::ZERO,

            Delta::from_secs(2),

        )?;



        let (mbox0, mbox1) = (

            regs::NV_PFALCON_FALCON_MAILBOX0::read(bar, &E::ID).value(),

drivers/gpu/nova-core/falcon/hal/ga102.rs

+7 −9
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
use core::marker::PhantomData;



use kernel::device;

use kernel::io::poll::read_poll_timeout;

use kernel::prelude::*;

use kernel::time::Delta;
@@ -11,7 +12,6 @@ 
    Falcon, FalconBromParams, FalconEngine, FalconModSelAlgo, PeregrineCoreSelect,

};

use crate::regs;

use crate::util;



use super::FalconHal;
@@ -23,14 +23,12 @@ fn select_core_ga102<E: FalconEngine>(bar: &Bar0) -> Result { 
            .write(bar, &E::ID);



        // TIMEOUT: falcon core should take less than 10ms to report being enabled.

        util::wait_on(Delta::from_millis(10), || {

            let r = regs::NV_PRISCV_RISCV_BCR_CTRL::read(bar, &E::ID);

            if r.valid() {

                Some(())

            } else {

                None

            }

        })?;

        read_poll_timeout(

            || Ok(regs::NV_PRISCV_RISCV_BCR_CTRL::read(bar, &E::ID)),

            |r| r.valid(),

            Delta::ZERO,

            Delta::from_millis(10),

        )?;

    }



    Ok(())

drivers/gpu/nova-core/gfw.rs

+16 −20
Original line number Diff line number Diff line
@@ -18,13 +18,12 @@ 
//!

//! Note that the devinit sequence also needs to run during suspend/resume.



use kernel::bindings;

use kernel::io::poll::read_poll_timeout;

use kernel::prelude::*;

use kernel::time::Delta;



use crate::driver::Bar0;

use crate::regs;

use crate::util;



/// Wait for the `GFW` (GPU firmware) boot completion signal (`GFW_BOOT`), or a 4 seconds timeout.

///
@@ -50,22 +49,19 @@ pub(crate) fn wait_gfw_boot_completion(bar: &Bar0) -> Result { 
    //

    // TIMEOUT: arbitrarily large value. GFW starts running immediately after the GPU is put out of

    // reset, and should complete in less time than that.

    util::wait_on(Delta::from_secs(4), || {

        // Check that FWSEC has lowered its protection level before reading the GFW_BOOT status.

        let gfw_booted = regs::NV_PGC6_AON_SECURE_SCRATCH_GROUP_05_PRIV_LEVEL_MASK::read(bar)

    read_poll_timeout(

        || {

            Ok(

                // Check that FWSEC has lowered its protection level before reading the GFW_BOOT

                // status.

                regs::NV_PGC6_AON_SECURE_SCRATCH_GROUP_05_PRIV_LEVEL_MASK::read(bar)

                    .read_protection_level0()

            && regs::NV_PGC6_AON_SECURE_SCRATCH_GROUP_05_0_GFW_BOOT::read(bar).completed();



        if gfw_booted {

            Some(())

        } else {

            // TODO[DLAY]: replace with [1] once it merges.

            // [1] https://lore.kernel.org/rust-for-linux/20250423192857.199712-6-fujita.tomonori@gmail.com/

            //

            // SAFETY: `msleep()` is safe to call with any parameter.

            unsafe { bindings::msleep(1) };



            None

        }

    })

                    && regs::NV_PGC6_AON_SECURE_SCRATCH_GROUP_05_0_GFW_BOOT::read(bar).completed(),

            )

        },

        |&gfw_booted| gfw_booted,

        Delta::from_millis(1),

        Delta::from_secs(4),

    )

    .map(|_| ())

}

drivers/gpu/nova-core/nova_core.rs

+0 −1
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 
mod gpu;

mod gsp;

mod regs;

mod util;

mod vbios;



pub(crate) const MODULE_NAME: &kernel::str::CStr = <LocalModule as kernel::ModuleMetadata>::NAME;