Previously, bitfields were hardcoded to use u32 as the underlying
storage type. Add support for different storage types (u8, u16, u32,
u64) to the bitfield macro.
New syntax is: struct Name: <type ex., u32> { ... }
Reviewed-by: Elle Rhumsaa <[email protected]>
Signed-off-by: Joel Fernandes <[email protected]>
---
drivers/gpu/nova-core/bitfield.rs | 210 ++++++++++++++-------------
drivers/gpu/nova-core/regs/macros.rs | 16 +-
2 files changed, 119 insertions(+), 107 deletions(-)
diff --git a/drivers/gpu/nova-core/bitfield.rs
b/drivers/gpu/nova-core/bitfield.rs
index b1e1c438b8a8..75de1c0fcb3b 100644
--- a/drivers/gpu/nova-core/bitfield.rs
+++ b/drivers/gpu/nova-core/bitfield.rs
@@ -3,96 +3,99 @@
//! Bitfield library for Rust structures
//!
//! Support for defining bitfields in Rust structures. Also used by the
[`register!`] macro.
-//!
-//! # Syntax
-//!
-//! ```rust
-//! use nova_core::bitfield;
-//!
-//! #[derive(Debug, Clone, Copy, Default)]
-//! enum Mode {
-//! #[default]
-//! Low = 0,
-//! High = 1,
-//! Auto = 2,
-//! }
-//!
-//! impl TryFrom<u8> for Mode {
-//! type Error = u8;
-//! fn try_from(value: u8) -> Result<Self, Self::Error> {
-//! match value {
-//! 0 => Ok(Mode::Low),
-//! 1 => Ok(Mode::High),
-//! 2 => Ok(Mode::Auto),
-//! _ => Err(value),
-//! }
-//! }
-//! }
-//!
-//! impl From<Mode> for u32 {
-//! fn from(mode: Mode) -> u32 {
-//! mode as u32
-//! }
-//! }
-//!
-//! #[derive(Debug, Clone, Copy, Default)]
-//! enum State {
-//! #[default]
-//! Inactive = 0,
-//! Active = 1,
-//! }
-//!
-//! impl From<bool> for State {
-//! fn from(value: bool) -> Self {
-//! if value { State::Active } else { State::Inactive }
-//! }
-//! }
-//!
-//! impl From<State> for u32 {
-//! fn from(state: State) -> u32 {
-//! state as u32
-//! }
-//! }
-//!
-//! bitfield! {
-//! struct ControlReg {
-//! 3:0 mode as u8 ?=> Mode;
-//! 7:7 state as bool => State;
-//! }
-//! }
-//! ```
-//!
-//! This generates a struct with:
-//! - Field accessors: `mode()`, `state()`, etc.
-//! - Field setters: `set_mode()`, `set_state()`, etc. (supports chaining with
builder pattern).
-//! - Debug and Default implementations.
-//!
-//! Fields are defined as follows:
-//!
-//! - `as <type>` simply returns the field value casted to <type>, typically
`u32`, `u16`, `u8` or
-//! `bool`. Note that `bool` fields must have a range of 1 bit.
-//! - `as <type> => <into_type>` calls `<into_type>`'s `From::<<type>>`
implementation and returns
-//! the result.
-//! - `as <type> ?=> <try_into_type>` calls `<try_into_type>`'s
`TryFrom::<<type>>` implementation
-//! and returns the result. This is useful with fields for which not all
values are valid.
-//!
+
+/// Defines a struct with accessors to access bits within an inner unsigned
integer.
+///
+/// # Syntax
+///
+/// ```rust
+/// use nova_core::bitfield;
+///
+/// #[derive(Debug, Clone, Copy, Default)]
+/// enum Mode {
+/// #[default]
+/// Low = 0,
+/// High = 1,
+/// Auto = 2,
+/// }
+///
+/// impl TryFrom<u8> for Mode {
+/// type Error = u8;
+/// fn try_from(value: u8) -> Result<Self, Self::Error> {
+/// match value {
+/// 0 => Ok(Mode::Low),
+/// 1 => Ok(Mode::High),
+/// 2 => Ok(Mode::Auto),
+/// _ => Err(value),
+/// }
+/// }
+/// }
+///
+/// impl From<Mode> for u32 {
+/// fn from(mode: Mode) -> u32 {
+/// mode as u32
+/// }
+/// }
+///
+/// #[derive(Debug, Clone, Copy, Default)]
+/// enum State {
+/// #[default]
+/// Inactive = 0,
+/// Active = 1,
+/// }
+///
+/// impl From<bool> for State {
+/// fn from(value: bool) -> Self {
+/// if value { State::Active } else { State::Inactive }
+/// }
+/// }
+///
+/// impl From<State> for u32 {
+/// fn from(state: State) -> u32 {
+/// state as u32
+/// }
+/// }
+///
+/// bitfield! {
+/// struct ControlReg(u32) {
+/// 3:0 mode as u8 ?=> Mode;
+/// 7:7 state as bool => State;
+/// }
+/// }
+/// ```
+///
+/// This generates a struct with:
+/// - Field accessors: `mode()`, `state()`, etc.
+/// - Field setters: `set_mode()`, `set_state()`, etc. (supports chaining with
builder pattern).
+/// Note that the compiler will error out if the size of the setter's arg
exceeds the
+/// struct's storage size.
+/// - Debug and Default implementations.
+///
+/// Fields are defined as follows:
+///
+/// - `as <type>` simply returns the field value casted to <type>, typically
`u32`, `u16`, `u8` or
+/// `bool`. Note that `bool` fields must have a range of 1 bit.
+/// - `as <type> => <into_type>` calls `<into_type>`'s `From::<<type>>`
implementation and returns
+/// the result.
+/// - `as <type> ?=> <try_into_type>` calls `<try_into_type>`'s
`TryFrom::<<type>>` implementation
+/// and returns the result. This is useful with fields for which not all
values are valid.
macro_rules! bitfield {
// Main entry point - defines the bitfield struct with fields
- (struct $name:ident $(, $comment:literal)? { $($fields:tt)* }) => {
- bitfield!(@core $name $(, $comment)? { $($fields)* });
+ (struct $name:ident($storage:ty) $(, $comment:literal)? { $($fields:tt)*
}) => {
+ bitfield!(@core $name $storage $(, $comment)? { $($fields)* });
};
// All rules below are helpers.
// Defines the wrapper `$name` type, as well as its relevant
implementations (`Debug`,
// `Default`, `BitOr`, and conversion to the value type) and field
accessor methods.
- (@core $name:ident $(, $comment:literal)? { $($fields:tt)* }) => {
+ (@core $name:ident $storage:ty $(, $comment:literal)? { $($fields:tt)* })
=> {
$(
#[doc=$comment]
)?
#[repr(transparent)]
#[derive(Clone, Copy)]
- pub(crate) struct $name(u32);
+ pub(crate) struct $name($storage);
impl ::core::ops::BitOr for $name {
type Output = Self;
@@ -102,20 +105,20 @@ fn bitor(self, rhs: Self) -> Self::Output {
}
}
- impl ::core::convert::From<$name> for u32 {
- fn from(val: $name) -> u32 {
+ impl ::core::convert::From<$name> for $storage {
+ fn from(val: $name) -> $storage {
val.0
}
}
- bitfield!(@fields_dispatcher $name { $($fields)* });
+ bitfield!(@fields_dispatcher $name $storage { $($fields)* });
};
// Captures the fields and passes them to all the implementers that
require field information.
//
// Used to simplify the matching rules for implementers, so they don't
need to match the entire
// complex fields rule even though they only make use of part of it.
- (@fields_dispatcher $name:ident {
+ (@fields_dispatcher $name:ident $storage:ty {
$($hi:tt:$lo:tt $field:ident as $type:tt
$(?=> $try_into_type:ty)?
$(=> $into_type:ty)?
@@ -124,7 +127,7 @@ fn from(val: $name) -> u32 {
)*
}
) => {
- bitfield!(@field_accessors $name {
+ bitfield!(@field_accessors $name $storage {
$(
$hi:$lo $field as $type
$(?=> $try_into_type)?
@@ -139,7 +142,7 @@ fn from(val: $name) -> u32 {
// Defines all the field getter/setter methods for `$name`.
(
- @field_accessors $name:ident {
+ @field_accessors $name:ident $storage:ty {
$($hi:tt:$lo:tt $field:ident as $type:tt
$(?=> $try_into_type:ty)?
$(=> $into_type:ty)?
@@ -155,7 +158,7 @@ fn from(val: $name) -> u32 {
#[allow(dead_code)]
impl $name {
$(
- bitfield!(@field_accessor $name $hi:$lo $field as $type
+ bitfield!(@field_accessor $name $storage, $hi:$lo $field as $type
$(?=> $try_into_type)?
$(=> $into_type)?
$(, $comment)?
@@ -189,11 +192,11 @@ impl $name {
// Catches fields defined as `bool` and convert them into a boolean value.
(
- @field_accessor $name:ident $hi:tt:$lo:tt $field:ident as bool =>
$into_type:ty
+ @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as
bool => $into_type:ty
$(, $comment:literal)?;
) => {
bitfield!(
- @leaf_accessor $name $hi:$lo $field
+ @leaf_accessor $name $storage, $hi:$lo $field
{ |f| <$into_type>::from(if f != 0 { true } else { false }) }
$into_type => $into_type $(, $comment)?;
);
@@ -201,17 +204,17 @@ impl $name {
// Shortcut for fields defined as `bool` without the `=>` syntax.
(
- @field_accessor $name:ident $hi:tt:$lo:tt $field:ident as bool $(,
$comment:literal)?;
+ @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as
bool $(, $comment:literal)?;
) => {
- bitfield!(@field_accessor $name $hi:$lo $field as bool => bool $(,
$comment)?;);
+ bitfield!(@field_accessor $name $storage, $hi:$lo $field as bool =>
bool $(, $comment)?;);
};
// Catches the `?=>` syntax for non-boolean fields.
(
- @field_accessor $name:ident $hi:tt:$lo:tt $field:ident as $type:tt ?=>
$try_into_type:ty
+ @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as
$type:tt ?=> $try_into_type:ty
$(, $comment:literal)?;
) => {
- bitfield!(@leaf_accessor $name $hi:$lo $field
+ bitfield!(@leaf_accessor $name $storage, $hi:$lo $field
{ |f| <$try_into_type>::try_from(f as $type) } $try_into_type =>
::core::result::Result<
$try_into_type,
@@ -222,29 +225,38 @@ impl $name {
// Catches the `=>` syntax for non-boolean fields.
(
- @field_accessor $name:ident $hi:tt:$lo:tt $field:ident as $type:tt =>
$into_type:ty
+ @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as
$type:tt => $into_type:ty
$(, $comment:literal)?;
) => {
- bitfield!(@leaf_accessor $name $hi:$lo $field
+ bitfield!(@leaf_accessor $name $storage, $hi:$lo $field
{ |f| <$into_type>::from(f as $type) } $into_type => $into_type
$(, $comment)?;);
};
// Shortcut for non-boolean fields defined without the `=>` or `?=>`
syntax.
(
- @field_accessor $name:ident $hi:tt:$lo:tt $field:ident as $type:tt
+ @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as
$type:tt
$(, $comment:literal)?;
) => {
- bitfield!(@field_accessor $name $hi:$lo $field as $type => $type $(,
$comment)?;);
+ bitfield!(@field_accessor $name $storage, $hi:$lo $field as $type =>
$type $(, $comment)?;);
};
// Generates the accessor methods for a single field.
(
- @leaf_accessor $name:ident $hi:tt:$lo:tt $field:ident
+ @leaf_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident
{ $process:expr } $to_type:ty => $res_type:ty $(,
$comment:literal)?;
) => {
::kernel::macros::paste!(
const [<$field:upper _RANGE>]: ::core::ops::RangeInclusive<u8> =
$lo..=$hi;
- const [<$field:upper _MASK>]: u32 = ((((1 << $hi) - 1) << 1) + 1) -
((1 << $lo) - 1);
+ const [<$field:upper _MASK>]: $storage = {
+ // Generate mask for shifting
+ match ::core::mem::size_of::<$storage>() {
+ 1 => ::kernel::bits::genmask_u8($lo..=$hi) as $storage,
+ 2 => ::kernel::bits::genmask_u16($lo..=$hi) as $storage,
+ 4 => ::kernel::bits::genmask_u32($lo..=$hi) as $storage,
+ 8 => ::kernel::bits::genmask_u64($lo..=$hi) as $storage,
+ _ => ::kernel::build_error!("Unsupported storage type size")
+ }
+ };
const [<$field:upper _SHIFT>]: u32 = Self::[<$field:upper
_MASK>].trailing_zeros();
);
@@ -255,7 +267,7 @@ impl $name {
#[inline(always)]
pub(crate) fn $field(self) -> $res_type {
::kernel::macros::paste!(
- const MASK: u32 = $name::[<$field:upper _MASK>];
+ const MASK: $storage = $name::[<$field:upper _MASK>];
const SHIFT: u32 = $name::[<$field:upper _SHIFT>];
);
let field = ((self.0 & MASK) >> SHIFT);
@@ -270,9 +282,9 @@ pub(crate) fn $field(self) -> $res_type {
)?
#[inline(always)]
pub(crate) fn [<set_ $field>](mut self, value: $to_type) -> Self {
- const MASK: u32 = $name::[<$field:upper _MASK>];
+ const MASK: $storage = $name::[<$field:upper _MASK>];
const SHIFT: u32 = $name::[<$field:upper _SHIFT>];
- let value = (u32::from(value) << SHIFT) & MASK;
+ let value = (<$storage>::from(value) << SHIFT) & MASK;
self.0 = (self.0 & !MASK) | value;
self
diff --git a/drivers/gpu/nova-core/regs/macros.rs
b/drivers/gpu/nova-core/regs/macros.rs
index 945d15a2c529..ffd7d5cb73bb 100644
--- a/drivers/gpu/nova-core/regs/macros.rs
+++ b/drivers/gpu/nova-core/regs/macros.rs
@@ -276,25 +276,25 @@ pub(crate) trait RegisterBase<T> {
macro_rules! register {
// Creates a register at a fixed offset of the MMIO space.
($name:ident @ $offset:literal $(, $comment:literal)? { $($fields:tt)* } )
=> {
- bitfield!(struct $name $(, $comment)? { $($fields)* } );
+ bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
register!(@io_fixed $name @ $offset);
};
// Creates an alias register of fixed offset register `alias` with its own
fields.
($name:ident => $alias:ident $(, $comment:literal)? { $($fields:tt)* } )
=> {
- bitfield!(struct $name $(, $comment)? { $($fields)* } );
+ bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
register!(@io_fixed $name @ $alias::OFFSET);
};
// Creates a register at a relative offset from a base address provider.
($name:ident @ $base:ty [ $offset:literal ] $(, $comment:literal)? {
$($fields:tt)* } ) => {
- bitfield!(struct $name $(, $comment)? { $($fields)* } );
+ bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
register!(@io_relative $name @ $base [ $offset ]);
};
// Creates an alias register of relative offset register `alias` with its
own fields.
($name:ident => $base:ty [ $alias:ident ] $(, $comment:literal)? {
$($fields:tt)* }) => {
- bitfield!(struct $name $(, $comment)? { $($fields)* } );
+ bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
register!(@io_relative $name @ $base [ $alias::OFFSET ]);
};
@@ -305,7 +305,7 @@ macro_rules! register {
}
) => {
static_assert!(::core::mem::size_of::<u32>() <= $stride);
- bitfield!(struct $name $(, $comment)? { $($fields)* } );
+ bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
register!(@io_array $name @ $offset [ $size ; $stride ]);
};
@@ -326,7 +326,7 @@ macro_rules! register {
$(, $comment:literal)? { $($fields:tt)* }
) => {
static_assert!(::core::mem::size_of::<u32>() <= $stride);
- bitfield!(struct $name $(, $comment)? { $($fields)* } );
+ bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
register!(@io_relative_array $name @ $base [ $offset [ $size ; $stride
] ]);
};
@@ -348,7 +348,7 @@ macro_rules! register {
}
) => {
static_assert!($idx < $alias::SIZE);
- bitfield!(struct $name $(, $comment)? { $($fields)* } );
+ bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
register!(@io_relative $name @ $base [ $alias::OFFSET + $idx *
$alias::STRIDE ] );
};
@@ -357,7 +357,7 @@ macro_rules! register {
// to avoid it being interpreted in place of the relative register array
alias rule.
($name:ident => $alias:ident [ $idx:expr ] $(, $comment:literal)? {
$($fields:tt)* }) => {
static_assert!($idx < $alias::SIZE);
- bitfield!(struct $name $(, $comment)? { $($fields)* } );
+ bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
register!(@io_fixed $name @ $alias::OFFSET + $idx * $alias::STRIDE );
};
--
2.34.1
