From a19bda861b3a79e25417462539df8b0d77c6b322 Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Thu, 16 Jul 2026 10:22:43 +0000 Subject: rust: device: avoid trailing ; in printing macros These macros are used like expressions, so they should not emit a semicolon. This is being turned into a hard error in a future release of Rust. error: trailing semicolon in macro used in expression position --> drivers/gpu/nova-core/firmware/fsp.rs:79:34 | 79 | .inspect_err(|_| dev_err!(dev, "FMC firmware missing '{}' section\n", name)) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #79813 = note: this error originates in the macro `dev_err` (in Nightly builds, run with -Z macro-backtrace for more info) [ I was doubly surprised since upstream made it a deny-by-default lint a year ago for Rust 1.91.0, and yet we didn't see it; plus I hadn't seen this in my CI even yesterday. It turns out this just landed into today's nightly (nightly-2026-07-16, using upstream commit d0babd8b6): Link: https://github.com/rust-lang/rust/pull/159222 which says: "The `semicolon_in_expressions_from_macros` lint previously suppressed warnings about non-local macros. This masks a lint that will subsequently become a hard error." So that explains it. And this is the PR that will make it a hard error at some point in the future: Link: https://github.com/rust-lang/rust/pull/159218 Thus starting with Rust 1.99.0 (expected 2026-10-01), we will be seeing the deny-by-default lint above, so clean it up already. - Miguel ] Cc: stable@vger.kernel.org # Needed in 6.18.y and later. Link: https://github.com/rust-lang/rust/issues/79813 Signed-off-by: Alice Ryhl Reviewed-by: Gary Guo Acked-by: Danilo Krummrich Link: https://github.com/rust-lang/rust/pull/159218 Link: https://github.com/rust-lang/rust/pull/159222 Link: https://patch.msgid.link/20260716-device-trail-semicolon-v1-1-f48e9dcfae15@google.com [ Fixed typo. ] Signed-off-by: Miguel Ojeda --- rust/kernel/device.rs | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) (limited to 'rust/kernel') diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index 645afc49a27d..1a38b3bbdfb7 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -708,9 +708,7 @@ macro_rules! impl_device_context_into_aref { #[macro_export] macro_rules! dev_printk { ($method:ident, $dev:expr, $($f:tt)*) => { - { - $crate::device::Device::$method($dev.as_ref(), $crate::prelude::fmt!($($f)*)) - } + $crate::device::Device::$method($dev.as_ref(), $crate::prelude::fmt!($($f)*)) } } @@ -737,7 +735,7 @@ macro_rules! dev_printk { /// ``` #[macro_export] macro_rules! dev_emerg { - ($($f:tt)*) => { $crate::dev_printk!(pr_emerg, $($f)*); } + ($($f:tt)*) => { $crate::dev_printk!(pr_emerg, $($f)*) } } /// Prints an alert-level message (level 1) prefixed with device information. @@ -763,7 +761,7 @@ macro_rules! dev_emerg { /// ``` #[macro_export] macro_rules! dev_alert { - ($($f:tt)*) => { $crate::dev_printk!(pr_alert, $($f)*); } + ($($f:tt)*) => { $crate::dev_printk!(pr_alert, $($f)*) } } /// Prints a critical-level message (level 2) prefixed with device information. @@ -789,7 +787,7 @@ macro_rules! dev_alert { /// ``` #[macro_export] macro_rules! dev_crit { - ($($f:tt)*) => { $crate::dev_printk!(pr_crit, $($f)*); } + ($($f:tt)*) => { $crate::dev_printk!(pr_crit, $($f)*) } } /// Prints an error-level message (level 3) prefixed with device information. @@ -815,7 +813,7 @@ macro_rules! dev_crit { /// ``` #[macro_export] macro_rules! dev_err { - ($($f:tt)*) => { $crate::dev_printk!(pr_err, $($f)*); } + ($($f:tt)*) => { $crate::dev_printk!(pr_err, $($f)*) } } /// Prints a warning-level message (level 4) prefixed with device information. @@ -841,7 +839,7 @@ macro_rules! dev_err { /// ``` #[macro_export] macro_rules! dev_warn { - ($($f:tt)*) => { $crate::dev_printk!(pr_warn, $($f)*); } + ($($f:tt)*) => { $crate::dev_printk!(pr_warn, $($f)*) } } /// Prints a notice-level message (level 5) prefixed with device information. @@ -867,7 +865,7 @@ macro_rules! dev_warn { /// ``` #[macro_export] macro_rules! dev_notice { - ($($f:tt)*) => { $crate::dev_printk!(pr_notice, $($f)*); } + ($($f:tt)*) => { $crate::dev_printk!(pr_notice, $($f)*) } } /// Prints an info-level message (level 6) prefixed with device information. @@ -893,7 +891,7 @@ macro_rules! dev_notice { /// ``` #[macro_export] macro_rules! dev_info { - ($($f:tt)*) => { $crate::dev_printk!(pr_info, $($f)*); } + ($($f:tt)*) => { $crate::dev_printk!(pr_info, $($f)*) } } /// Prints a debug-level message (level 7) prefixed with device information. @@ -919,5 +917,5 @@ macro_rules! dev_info { /// ``` #[macro_export] macro_rules! dev_dbg { - ($($f:tt)*) => { $crate::dev_printk!(pr_dbg, $($f)*); } + ($($f:tt)*) => { $crate::dev_printk!(pr_dbg, $($f)*) } } -- cgit v1.2.3 From 880c43b185ca52239e75bc546cc4f4d9154d0fed Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Tue, 14 Jul 2026 07:52:35 +0900 Subject: rust: time: fix as_micros_ceil() to round correctly for negative Delta The ceiling-division idiom `(n + d - 1) / d` only produces the correct result when `n` is non-negative. For example, if n = -1000 (exactly -1us), the old code computed (-1000 + 999) / 1000 == 0 instead of -1. For negative n, truncating division already rounds towards positive infinity, so no bias is needed in that case. Fixes: fae0cdc12340 ("rust: time: Introduce Delta type") Signed-off-by: FUJITA Tomonori Acked-by: Andreas Hindborg Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260713225235.3243480-1-tomo@flapping.org Signed-off-by: Miguel Ojeda --- rust/kernel/time.rs | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'rust/kernel') diff --git a/rust/kernel/time.rs b/rust/kernel/time.rs index 363e93cbb139..b8463823aed9 100644 --- a/rust/kernel/time.rs +++ b/rust/kernel/time.rs @@ -441,15 +441,22 @@ impl Delta { /// to the value in the [`Delta`]. #[inline] pub fn as_micros_ceil(self) -> i64 { + let n = self.as_nanos(); + let n = if n >= 0 { + n.saturating_add(NSEC_PER_USEC - 1) + } else { + n + }; + #[cfg(CONFIG_64BIT)] { - self.as_nanos().saturating_add(NSEC_PER_USEC - 1) / NSEC_PER_USEC + n / NSEC_PER_USEC } #[cfg(not(CONFIG_64BIT))] // SAFETY: It is always safe to call `ktime_to_us()` with any value. unsafe { - bindings::ktime_to_us(self.as_nanos().saturating_add(NSEC_PER_USEC - 1)) + bindings::ktime_to_us(n) } } -- cgit v1.2.3 From 4f5f23846d6713c05481c8cfc710bb23817bf5e9 Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Wed, 5 Aug 2026 23:28:35 +0200 Subject: rust: io: gate ioremap/iounmap on CONFIG_HAS_IOMEM s390 does not provide ioremap()/iounmap() when CONFIG_HAS_IOMEM is not set (which requires CONFIG_PCI on that architecture). This causes a build failure with Rust enabled on e.g. s390 allnoconfig: In file included from rust/helpers/helpers.c:68: rust/helpers/io.c:8:9: error: call to undeclared function 'ioremap'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 8 | return ioremap(offset, size); | ^ rust/helpers/io.c:19:2: error: call to undeclared function 'iounmap'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 19 | iounmap(addr); Guard the C helpers behind #ifdef CONFIG_HAS_IOMEM and cfg-gate the Rust io::mem module, such that IoMem, ExclusiveIoMem and IoRequest are not available without CONFIG_HAS_IOMEM. Note that the C API is inconsistent about this. For instance, devm_ioremap() has no stub and produces a link failure without CONFIG_HAS_IOMEM, whereas devm_platform_ioremap_resource() provides an inline stub returning -EINVAL. The approach taken here (compile-time gating) matches the former, which is slightly more appropriate since any driver performing MMIO currently requires CONFIG_HAS_IOMEM. Ideally, s390 should provide ioremap()/iounmap() stubs unconditionally (as UML already does), removing the need for any config gating as discussed in [1]; a follow-up patch for s390 is expected. Cc: Arnd Bergmann Reported-by: Miguel Ojeda Closes: https://lore.kernel.org/all/20260803180931.97202-1-ojeda@kernel.org [1] Fixes: 3f70ebe63858 ("s390: Enable Rust support") Reviewed-by: Arnd Bergmann Link: https://patch.msgid.link/20260805212920.1996937-1-dakr@kernel.org Signed-off-by: Danilo Krummrich --- rust/kernel/io.rs | 1 + rust/kernel/platform.rs | 9 +++++---- 2 files changed, 6 insertions(+), 4 deletions(-) (limited to 'rust/kernel') diff --git a/rust/kernel/io.rs b/rust/kernel/io.rs index fcc7678fd9e3..d30bb5c6d4fc 100644 --- a/rust/kernel/io.rs +++ b/rust/kernel/io.rs @@ -9,6 +9,7 @@ use crate::{ prelude::*, // }; +#[cfg(CONFIG_HAS_IOMEM)] pub mod mem; pub mod poll; pub mod register; diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs index 9b362e0495d3..d41555a4b31d 100644 --- a/rust/kernel/platform.rs +++ b/rust/kernel/platform.rs @@ -17,10 +17,7 @@ use crate::{ from_result, to_result, // }, - io::{ - mem::IoRequest, - Resource, // - }, + io::Resource, irq::{ self, IrqRequest, // @@ -31,6 +28,9 @@ use crate::{ ThisModule, // }; +#[cfg(CONFIG_HAS_IOMEM)] +use crate::io::mem::IoRequest; + use core::{ marker::PhantomData, mem::offset_of, @@ -307,6 +307,7 @@ impl Device { } } +#[cfg(CONFIG_HAS_IOMEM)] impl Device { /// Returns an `IoRequest` for the resource at `index`, if any. pub fn io_request_by_index(&self, index: u32) -> Option> { -- cgit v1.2.3 From f88db65aece9f9d26287b6377b7c7730ecf9f11a Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Wed, 5 Aug 2026 23:28:36 +0200 Subject: rust: io: gate ioremap doctests on CONFIG_HAS_IOMEM The doc examples in io.rs and devres.rs directly call bindings::ioremap() and bindings::iounmap(), which do not exist when CONFIG_HAS_IOMEM is not set. This causes build failures with CONFIG_RUST_KERNEL_DOCTESTS=y on such configurations (e.g. s390 allnoconfig). Gate the affected doctests with `#![cfg(CONFIG_HAS_IOMEM)]` so they are skipped when IOMEM is unavailable. Fixes: 3f70ebe63858 ("s390: Enable Rust support") Reviewed-by: Arnd Bergmann Link: https://patch.msgid.link/20260805212920.1996937-2-dakr@kernel.org Signed-off-by: Danilo Krummrich --- rust/kernel/devres.rs | 1 + rust/kernel/io.rs | 1 + 2 files changed, 2 insertions(+) (limited to 'rust/kernel') diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs index 11ce500e9b76..8ff8aedf251a 100644 --- a/rust/kernel/devres.rs +++ b/rust/kernel/devres.rs @@ -59,6 +59,7 @@ struct Inner { /// # Examples /// /// ```no_run +/// # #![cfg(CONFIG_HAS_IOMEM)] /// use kernel::{ /// bindings, /// device::{ diff --git a/rust/kernel/io.rs b/rust/kernel/io.rs index d30bb5c6d4fc..d4063ee41200 100644 --- a/rust/kernel/io.rs +++ b/rust/kernel/io.rs @@ -81,6 +81,7 @@ impl MmioRaw { /// # Examples /// /// ```no_run +/// # #![cfg(CONFIG_HAS_IOMEM)] /// use kernel::{ /// bindings, /// ffi::c_void, -- cgit v1.2.3