{"id":2229247,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2229247/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-pwm/patch/20260427221155.2144848-22-dakr@kernel.org/","project":{"id":38,"url":"http://patchwork.ozlabs.org/api/1.1/projects/38/?format=json","name":"Linux PWM development","link_name":"linux-pwm","list_id":"linux-pwm.vger.kernel.org","list_email":"linux-pwm@vger.kernel.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260427221155.2144848-22-dakr@kernel.org>","date":"2026-04-27T22:11:19","name":"[REF,21/24] gpu: nova-core: use HRT lifetime for Bar","commit_ref":null,"pull_url":null,"state":"handled-elsewhere","archived":false,"hash":"22a862e06bafd582c1189d79532501812596dee2","submitter":{"id":89037,"url":"http://patchwork.ozlabs.org/api/1.1/people/89037/?format=json","name":"Danilo Krummrich","email":"dakr@kernel.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-pwm/patch/20260427221155.2144848-22-dakr@kernel.org/mbox/","series":[{"id":501734,"url":"http://patchwork.ozlabs.org/api/1.1/series/501734/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-pwm/list/?series=501734","date":"2026-04-27T22:10:58","name":"rust: device: Higher-Ranked Lifetime Types for device drivers","version":1,"mbox":"http://patchwork.ozlabs.org/series/501734/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2229247/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2229247/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pwm@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=W75RH2Y9;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; 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a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1777328061; cv=none;\n b=IJKy0C9T/8i4UCmnXqSbI9bRY27h+WvjHLHgNbnfqDgnRION4TtvW4ztTGzMqKybWaNXnrFjyZ6vxvIs4W+L5FniK+Y23CvF7wrlOuiquB2kQUHXUrnDQPZz+KGiE5ZcPSTj8nixD+AR1g9R2kDQa/nXsF+K6J6O/yJezOg21Zw=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1777328061; c=relaxed/simple;\n\tbh=+vCZJoneZObXHz+HrSLsZDDMk+BGXI4VJJ4WNODomsU=;\n\th=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References:\n\t MIME-Version;\n b=MOLQswjRkWU25KCwDxL1ie0+sm2zcfLl8KVLwV0mAuk7a8dR5LFePXjk4u7niBd/pPw/6RNp5edDnEDbyg+aBIXIv9VBd5fA6x1sobmLqvs4LJ9WmGYFJTfYAXGVoOFKagxTdMAUbq+8yXH0sn1+99FlLA5qudp6pM4J8/PDs10=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org\n header.b=W75RH2Y9; arc=none smtp.client-ip=10.30.226.201","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1777328060;\n\tbh=+vCZJoneZObXHz+HrSLsZDDMk+BGXI4VJJ4WNODomsU=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=W75RH2Y9F/+siwPQ1JHURZcogobZ9/VrlGLtxYgFA1gLCsqjOxrPQg1XKsISLV87C\n\t fQsa1U+tA3GM6aDw9oqcXpq5cLE+zLKREDMDG8R4OU9DliimeWPWQlG3kyJA7b5S7z\n\t ooGGLlzy1lXyPGwJ5q3stU6oLo6vInOjyWIa6D2C/FoLh6wMzJiRKEiVCBmR3IQgKe\n\t K7BFdXEiftt7WobIFyHxAHliiFeowDzCMDGRqPmLbKKR/m4a1yUzwHJVmPydCDKmIG\n\t yGznAjvJr6qehxk0Y5WUo7FrhKCcPUS5wIOfw08fSkAlbj9rXqvhoP1GC5FQqwFXIw\n\t pUy8/Ka1tYgpA==","From":"Danilo Krummrich ","To":"gregkh@linuxfoundation.org,\n\trafael@kernel.org,\n\tacourbot@nvidia.com,\n\taliceryhl@google.com,\n\tdavid.m.ertman@intel.com,\n\tira.weiny@intel.com,\n\tleon@kernel.org,\n\tviresh.kumar@linaro.org,\n\tm.wilczynski@samsung.com,\n\tukleinek@kernel.org,\n\tbhelgaas@google.com,\n\tkwilczynski@kernel.org,\n\tabdiel.janulgue@gmail.com,\n\trobin.murphy@arm.com,\n\tmarkus.probst@posteo.de,\n\tojeda@kernel.org,\n\tboqun@kernel.org,\n\tgary@garyguo.net,\n\tbjorn3_gh@protonmail.com,\n\tlossin@kernel.org,\n\ta.hindborg@kernel.org,\n\ttmgross@umich.edu","Cc":"driver-core@lists.linux.dev,\n\tlinux-kernel@vger.kernel.org,\n\tnova-gpu@lists.linux.dev,\n\tdri-devel@lists.freedesktop.org,\n\tlinux-pm@vger.kernel.org,\n\tlinux-pwm@vger.kernel.org,\n\tlinux-pci@vger.kernel.org,\n\trust-for-linux@vger.kernel.org,\n\tDanilo Krummrich ","Subject":"[PATCH REF 21/24] gpu: nova-core: use HRT lifetime for Bar","Date":"Tue, 28 Apr 2026 00:11:19 +0200","Message-ID":"<20260427221155.2144848-22-dakr@kernel.org>","X-Mailer":"git-send-email 2.54.0","In-Reply-To":"<20260427221155.2144848-1-dakr@kernel.org>","References":"<20260427221155.2144848-1-dakr@kernel.org>","Precedence":"bulk","X-Mailing-List":"linux-pwm@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit"},"content":"Take advantage of the lifetime-parameterized pci::Bar<'a> to hold the\nBAR mapping directly in NovaCore<'a>, and pass a borrowed reference to\nGpu<'a>.\n\nThis eliminates the Arc> indirection, removes runtime\nrevocation checks for BAR access, and simplifies Gpu::unbind().\n\nSigned-off-by: Danilo Krummrich \n---\n drivers/gpu/nova-core/driver.rs | 40 ++++++++++++++----------------\n drivers/gpu/nova-core/gpu.rs | 27 ++++++++------------\n drivers/gpu/nova-core/nova_core.rs | 2 +-\n 3 files changed, 30 insertions(+), 39 deletions(-)","diff":"diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs\nindex 149a20748e86..ec9cecb30f63 100644\n--- a/drivers/gpu/nova-core/driver.rs\n+++ b/drivers/gpu/nova-core/driver.rs\n@@ -14,12 +14,9 @@\n },\n prelude::*,\n sizes::SZ_16M,\n- sync::{\n- atomic::{\n- Atomic,\n- Relaxed, //\n- },\n- Arc,\n+ sync::atomic::{\n+ Atomic,\n+ Relaxed, //\n },\n types::ForLt,\n };\n@@ -30,9 +27,10 @@\n static AUXILIARY_ID_COUNTER: Atomic = Atomic::new(0);\n \n #[pin_data]\n-pub(crate) struct NovaCore {\n+pub(crate) struct NovaCore<'a> {\n #[pin]\n- pub(crate) gpu: Gpu,\n+ pub(crate) gpu: Gpu<'a>,\n+ bar: pci::Bar<'a, BAR0_SIZE>,\n #[allow(clippy::type_complexity)]\n _reg: Devres>,\n }\n@@ -47,12 +45,12 @@ pub(crate) struct NovaCore {\n // DMA addresses. These systems should be quite rare.\n const GPU_DMA_BITS: u32 = 47;\n \n-pub(crate) type Bar0 = pci::Bar<'static, BAR0_SIZE>;\n+pub(crate) type Bar0 = kernel::io::Mmio;\n \n kernel::pci_device_table!(\n PCI_TABLE,\n MODULE_PCI_TABLE,\n- >::IdInfo,\n+ as pci::Driver<'_>>::IdInfo,\n [\n // Modern NVIDIA GPUs will show up as either VGA or 3D controllers.\n (\n@@ -74,7 +72,7 @@ pub(crate) struct NovaCore {\n ]\n );\n \n-impl<'a> pci::Driver<'a> for NovaCore {\n+impl<'a> pci::Driver<'a> for NovaCore<'a> {\n type IdInfo = ();\n const ID_TABLE: pci::IdTable = &PCI_TABLE;\n \n@@ -93,14 +91,14 @@ fn probe(\n // other threads of execution.\n unsafe { pdev.dma_set_mask_and_coherent(DmaMask::new::())? };\n \n- let bar = Arc::new(\n- pdev.iomap_region_sized::(0, c\"nova-core/bar0\")?\n- .into_devres()?,\n- GFP_KERNEL,\n- )?;\n-\n- Ok(try_pin_init!(Self {\n- gpu <- Gpu::new(pdev, bar.clone(), bar.access(pdev.as_ref())?),\n+ Ok(try_pin_init!(NovaCore {\n+ bar: pdev.iomap_region_sized::(0, c\"nova-core/bar0\")?,\n+ // TODO: Use `&bar` self-referential pin-init syntax once available.\n+ //\n+ // SAFETY: `bar` is initialized before this expression is evaluated\n+ // (`try_pin_init!()` initializes fields in declaration order), lives at a pinned\n+ // stable address, and is dropped after `gpu` (struct field drop order).\n+ gpu <- Gpu::new(pdev, unsafe { &*core::ptr::from_ref(bar) }),\n _reg: auxiliary::Registration::new(\n pdev.as_ref(),\n c\"nova-drm\",\n@@ -114,7 +112,7 @@ fn probe(\n })\n }\n \n- fn unbind(pdev: &pci::Device, this: Pin<&Self>) {\n- this.gpu.unbind(pdev.as_ref());\n+ fn unbind(_pdev: &'a pci::Device, this: Pin<&'a Self>) {\n+ this.gpu.unbind();\n }\n }\ndiff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs\nindex 0f6fe9a1b955..922197f2aeef 100644\n--- a/drivers/gpu/nova-core/gpu.rs\n+++ b/drivers/gpu/nova-core/gpu.rs\n@@ -2,13 +2,11 @@\n \n use kernel::{\n device,\n- devres::Devres,\n fmt,\n io::Io,\n num::Bounded,\n pci,\n- prelude::*,\n- sync::Arc, //\n+ prelude::*, //\n };\n \n use crate::{\n@@ -224,10 +222,10 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {\n \n /// Structure holding the resources required to operate the GPU.\n #[pin_data]\n-pub(crate) struct Gpu {\n+pub(crate) struct Gpu<'a> {\n spec: Spec,\n- /// MMIO mapping of PCI BAR 0\n- bar: Arc>,\n+ /// MMIO mapping of PCI BAR 0.\n+ bar: &'a Bar0,\n /// System memory page required for flushing all pending GPU-side memory writes done through\n /// PCIE into system memory, via sysmembar (A GPU-initiated HW memory-barrier operation).\n sysmem_flush: SysmemFlush,\n@@ -240,10 +238,9 @@ pub(crate) struct Gpu {\n gsp: Gsp,\n }\n \n-impl Gpu {\n- pub(crate) fn new<'a>(\n+impl<'a> Gpu<'a> {\n+ pub(crate) fn new(\n pdev: &'a pci::Device,\n- devres_bar: Arc>,\n bar: &'a Bar0,\n ) -> impl PinInit + 'a {\n try_pin_init!(Self {\n@@ -257,6 +254,8 @@ pub(crate) fn new<'a>(\n .inspect_err(|_| dev_err!(pdev, \"GFW boot did not complete\\n\"))?;\n },\n \n+ bar,\n+\n sysmem_flush: SysmemFlush::register(pdev.as_ref(), bar, spec.chipset)?,\n \n gsp_falcon: Falcon::new(\n@@ -270,19 +269,13 @@ pub(crate) fn new<'a>(\n gsp <- Gsp::new(pdev),\n \n _: { gsp.boot(pdev, bar, spec.chipset, gsp_falcon, sec2_falcon)? },\n-\n- bar: devres_bar,\n })\n }\n \n /// Called when the corresponding [`Device`](device::Device) is unbound.\n ///\n /// Note: This method must only be called from `Driver::unbind`.\n- pub(crate) fn unbind(&self, dev: &device::Device) {\n- kernel::warn_on!(self\n- .bar\n- .access(dev)\n- .inspect(|bar| self.sysmem_flush.unregister(bar))\n- .is_err());\n+ pub(crate) fn unbind(&self) {\n+ self.sysmem_flush.unregister(self.bar);\n }\n }\ndiff --git a/drivers/gpu/nova-core/nova_core.rs b/drivers/gpu/nova-core/nova_core.rs\nindex 49c093a0cb42..ed5eb39c8201 100644\n--- a/drivers/gpu/nova-core/nova_core.rs\n+++ b/drivers/gpu/nova-core/nova_core.rs\n@@ -49,7 +49,7 @@ struct NovaCoreModule {\n // then `_debugfs_guard` clears `DEBUGFS_ROOT`.\n #[allow(clippy::type_complexity)]\n #[pin]\n- _driver: Registration>,\n+ _driver: Registration)>>,\n _debugfs_guard: DebugfsRootGuard,\n }\n \n","prefixes":["REF","21/24"]}