Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
rust: platform: impl TryFrom<&Device> for &platform::Device
Implement TryFrom<&device::Device> for &Device.
This allows us to get a &platform::Device from a generic &Device in a safe
way; the conversion fails if the device' bus type does not match with
the platform bus type.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250321214826.140946-4-dakr@kernel.org
[ Support device context types, use dev_is_platform() helper. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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-1
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rust/helpers/platform.c
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rust/helpers/platform.c
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rust/kernel/platform.rs
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rust/kernel/platform.rs
···
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//! C header: [`include/linux/platform_device.h`](srctree/include/linux/platform_device.h)
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use crate::{
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bindings, device, driver,
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bindings, container_of, device, driver,
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error::{to_result, Result},
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of,
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prelude::*,
···
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// SAFETY: `dev` points to a valid `struct device`.
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unsafe { device::Device::as_ref(dev) }
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}
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}
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impl<Ctx: device::DeviceContext> TryFrom<&device::Device<Ctx>> for &Device<Ctx> {
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type Error = kernel::error::Error;
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fn try_from(dev: &device::Device<Ctx>) -> Result<Self, Self::Error> {
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// SAFETY: By the type invariant of `Device`, `dev.as_raw()` is a valid pointer to a
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// `struct device`.
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if !unsafe { bindings::dev_is_platform(dev.as_raw()) } {
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return Err(EINVAL);
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}
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// SAFETY: We've just verified that the bus type of `dev` equals
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// `bindings::platform_bus_type`, hence `dev` must be embedded in a valid
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// `struct platform_device` as guaranteed by the corresponding C code.
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let pdev = unsafe { container_of!(dev.as_raw(), bindings::platform_device, dev) };
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// SAFETY: `pdev` is a valid pointer to a `struct platform_device`.
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Ok(unsafe { &*pdev.cast() })
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}
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}
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