From 584e61452f75bfeac2cdd83730b4059526ec60c7 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Sat, 12 Apr 2025 09:53:41 +0900 Subject: rust: helpers: Remove volatile qualifier from io helpers Remove the `volatile` qualifier used with __iomem in helper functions in io.c. These helper functions are just wrappers around the corresponding accessors so they are unnecessary. This fixes the following UML build error with CONFIG_RUST enabled: In file included from rust/helpers/helpers.c:19: rust/helpers/io.c:12:10: error: passing 'volatile void *' to parameter of type 'void *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers] 12 | iounmap(addr); | ^~~~ arch/um/include/asm/io.h:19:42: note: passing argument to parameter 'addr' here 19 | static inline void iounmap(void __iomem *addr) | ^ 1 error generated. [ Arnd explains [1] that removing the qualifier is the way forward (thanks!): Rihgt, I tried this last week when it came up first, removing the 'volatile' annotations in the asm-generic/io.h header and then all the ones that caused build regressions on arm/arm64/x86 randconfig and allmodconfig builds. This patch is a little longer than my original version as I did run into a few regressions later. As far as I can tell, none of these volatile annotations have any actual effect, and most of them date back to ancient kernels where this may have been required. Leaving it out of the rust interface is clearly the right way, and it shouldn't be too hard to upstream the changes below when we need to, but I also don't see any priority to send these. If anyone wants to help out, I can send them the whole patch. I created an issue [2] in case someone wants to help. - Miguel ] Fixes: ce30d94e6855 ("rust: add `io::{Io, IoRaw}` base types") Signed-off-by: FUJITA Tomonori Cc: stable@vger.kernel.org Reviewed-by: Danilo Krummrich Link: https://lore.kernel.org/rust-for-linux/0c844b70-19c7-4b14-ba29-fc99ae0d69f0@app.fastmail.com/ [1] Link: https://github.com/Rust-for-Linux/linux/issues/1156 [2] Link: https://lore.kernel.org/r/20250412005341.157150-1-fujita.tomonori@gmail.com [ Reworded for relative paths. - Miguel ] Signed-off-by: Miguel Ojeda --- rust/helpers/io.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) (limited to 'rust/helpers') diff --git a/rust/helpers/io.c b/rust/helpers/io.c index 4c2401ccd720..15ea187c5466 100644 --- a/rust/helpers/io.c +++ b/rust/helpers/io.c @@ -7,94 +7,94 @@ void __iomem *rust_helper_ioremap(phys_addr_t offset, size_t size) return ioremap(offset, size); } -void rust_helper_iounmap(volatile void __iomem *addr) +void rust_helper_iounmap(void __iomem *addr) { iounmap(addr); } -u8 rust_helper_readb(const volatile void __iomem *addr) +u8 rust_helper_readb(const void __iomem *addr) { return readb(addr); } -u16 rust_helper_readw(const volatile void __iomem *addr) +u16 rust_helper_readw(const void __iomem *addr) { return readw(addr); } -u32 rust_helper_readl(const volatile void __iomem *addr) +u32 rust_helper_readl(const void __iomem *addr) { return readl(addr); } #ifdef CONFIG_64BIT -u64 rust_helper_readq(const volatile void __iomem *addr) +u64 rust_helper_readq(const void __iomem *addr) { return readq(addr); } #endif -void rust_helper_writeb(u8 value, volatile void __iomem *addr) +void rust_helper_writeb(u8 value, void __iomem *addr) { writeb(value, addr); } -void rust_helper_writew(u16 value, volatile void __iomem *addr) +void rust_helper_writew(u16 value, void __iomem *addr) { writew(value, addr); } -void rust_helper_writel(u32 value, volatile void __iomem *addr) +void rust_helper_writel(u32 value, void __iomem *addr) { writel(value, addr); } #ifdef CONFIG_64BIT -void rust_helper_writeq(u64 value, volatile void __iomem *addr) +void rust_helper_writeq(u64 value, void __iomem *addr) { writeq(value, addr); } #endif -u8 rust_helper_readb_relaxed(const volatile void __iomem *addr) +u8 rust_helper_readb_relaxed(const void __iomem *addr) { return readb_relaxed(addr); } -u16 rust_helper_readw_relaxed(const volatile void __iomem *addr) +u16 rust_helper_readw_relaxed(const void __iomem *addr) { return readw_relaxed(addr); } -u32 rust_helper_readl_relaxed(const volatile void __iomem *addr) +u32 rust_helper_readl_relaxed(const void __iomem *addr) { return readl_relaxed(addr); } #ifdef CONFIG_64BIT -u64 rust_helper_readq_relaxed(const volatile void __iomem *addr) +u64 rust_helper_readq_relaxed(const void __iomem *addr) { return readq_relaxed(addr); } #endif -void rust_helper_writeb_relaxed(u8 value, volatile void __iomem *addr) +void rust_helper_writeb_relaxed(u8 value, void __iomem *addr) { writeb_relaxed(value, addr); } -void rust_helper_writew_relaxed(u16 value, volatile void __iomem *addr) +void rust_helper_writew_relaxed(u16 value, void __iomem *addr) { writew_relaxed(value, addr); } -void rust_helper_writel_relaxed(u32 value, volatile void __iomem *addr) +void rust_helper_writel_relaxed(u32 value, void __iomem *addr) { writel_relaxed(value, addr); } #ifdef CONFIG_64BIT -void rust_helper_writeq_relaxed(u64 value, volatile void __iomem *addr) +void rust_helper_writeq_relaxed(u64 value, void __iomem *addr) { writeq_relaxed(value, addr); } -- cgit v1.2.3 From c1b4071ec3a6a594df6c49bf8f04a60a88072525 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Sat, 12 Apr 2025 09:05:06 +0900 Subject: rust: helpers: Add dma_alloc_attrs() and dma_free_attrs() Add dma_alloc_attrs() and dma_free_attrs() helpers to fix a build error when CONFIG_HAS_DMA is not enabled. Note that when CONFIG_HAS_DMA is enabled, dma_alloc_attrs() and dma_free_attrs() are included in both bindings_generated.rs and bindings_helpers_generated.rs. The former takes precedence so behavior remains unchanged in that case. This fixes the following build error on UML: error[E0425]: cannot find function `dma_alloc_attrs` in crate `bindings` --> rust/kernel/dma.rs:171:23 | 171 | bindings::dma_alloc_attrs( | ^^^^^^^^^^^^^^^ help: a function with a similar name exists: `dma_alloc_pages` | ::: rust/bindings/bindings_generated.rs:44568:5 | 44568 | / pub fn dma_alloc_pages( 44569 | | dev: *mut device, 44570 | | size: usize, 44571 | | dma_handle: *mut dma_addr_t, 44572 | | dir: dma_data_direction, 44573 | | gfp: gfp_t, 44574 | | ) -> *mut page; | |___________________- similarly named function `dma_alloc_pages` defined here error[E0425]: cannot find function `dma_free_attrs` in crate `bindings` --> rust/kernel/dma.rs:293:23 | 293 | bindings::dma_free_attrs( | ^^^^^^^^^^^^^^ help: a function with a similar name exists: `dma_free_pages` | ::: rust/bindings/bindings_generated.rs:44577:5 | 44577 | / pub fn dma_free_pages( 44578 | | dev: *mut device, 44579 | | size: usize, 44580 | | page: *mut page, 44581 | | dma_handle: dma_addr_t, 44582 | | dir: dma_data_direction, 44583 | | ); | |______- similarly named function `dma_free_pages` defined here Fixes: ad2907b4e308 ("rust: add dma coherent allocator abstraction") Signed-off-by: FUJITA Tomonori Acked-by: Danilo Krummrich Link: https://lore.kernel.org/r/20250412000507.157000-1-fujita.tomonori@gmail.com [ Reworded for relative paths. - Miguel ] Signed-off-by: Miguel Ojeda --- MAINTAINERS | 1 + rust/helpers/dma.c | 16 ++++++++++++++++ rust/helpers/helpers.c | 1 + 3 files changed, 18 insertions(+) create mode 100644 rust/helpers/dma.c (limited to 'rust/helpers') diff --git a/MAINTAINERS b/MAINTAINERS index 96b827049501..bec614ef35d9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7020,6 +7020,7 @@ L: rust-for-linux@vger.kernel.org S: Supported W: https://rust-for-linux.com T: git https://github.com/Rust-for-Linux/linux.git alloc-next +F: rust/helpers/dma.c F: rust/kernel/dma.rs F: samples/rust/rust_dma.rs diff --git a/rust/helpers/dma.c b/rust/helpers/dma.c new file mode 100644 index 000000000000..df8b8a77355a --- /dev/null +++ b/rust/helpers/dma.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +void *rust_helper_dma_alloc_attrs(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t flag, + unsigned long attrs) +{ + return dma_alloc_attrs(dev, size, dma_handle, flag, attrs); +} + +void rust_helper_dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t dma_handle, unsigned long attrs) +{ + dma_free_attrs(dev, size, cpu_addr, dma_handle, attrs); +} diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c index e1c21eba9b15..1e7c84df7252 100644 --- a/rust/helpers/helpers.c +++ b/rust/helpers/helpers.c @@ -14,6 +14,7 @@ #include "cpumask.c" #include "cred.c" #include "device.c" +#include "dma.c" #include "err.c" #include "fs.c" #include "io.c" -- cgit v1.2.3