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Replace 'from' with 'as' in the setter implementation to support this. Suggested-by: Yury Norov Signed-off-by: Joel Fernandes --- rust/kernel/bits/bitfield.rs | 46 +++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) diff --git a/rust/kernel/bits/bitfield.rs b/rust/kernel/bits/bitfield.rs index 99e443580b36..6342352891fa 100644 --- a/rust/kernel/bits/bitfield.rs +++ b/rust/kernel/bits/bitfield.rs @@ -300,7 +300,7 @@ impl $name { $vis fn [](mut self, value: $to_type) -> Self { const MASK: $storage = $name::[<$field:upper _MASK>]; const SHIFT: u32 = $name::[<$field:upper _SHIFT>]; - let value = (<$storage>::from(value) << SHIFT) & MASK; + let value = ((value as $storage) << SHIFT) & MASK; self.0 = (self.0 & !MASK) | value; self @@ -452,6 +452,15 @@ struct TestPartialBits: u8 { } } + // For testing wide field types on narrow storage + bitfield! { + struct TestWideFields: u8 { + 3:0 nibble as u32; + 7:4 high_nibble as u32; + 7:0 full as u64; + } + } + #[test] fn test_single_bits() { let mut pte = TestPageTableEntry::default(); @@ -689,4 +698,39 @@ fn test_partial_bitfield() { bf2 = bf2.set_state(0x55); assert_eq!(bf2.state(), 0x1); } + + #[test] + fn test_wide_field_types() { + let mut wf = TestWideFields::default(); + + wf = wf.set_nibble(0x0000000F_u32); + assert_eq!(wf.nibble(), 0x0000000F_u32); + + wf = wf.set_high_nibble(0x00000007_u32); + assert_eq!(wf.high_nibble(), 0x00000007_u32); + + wf = wf.set_nibble(0xDEADBEEF_u32); + assert_eq!(wf.nibble(), 0x0000000F_u32); + + wf = wf.set_high_nibble(0xCAFEBABE_u32); + assert_eq!(wf.high_nibble(), 0x0000000E_u32); + + wf = wf.set_full(0xDEADBEEFCAFEBABE_u64); + assert_eq!(wf.full(), 0xBE_u64); + + assert_eq!(wf.raw(), 0xBE_u8); + + wf = TestWideFields::default() + .set_nibble(0x5_u32) + .set_high_nibble(0xA_u32); + assert_eq!(wf.raw(), 0xA5_u8); + assert_eq!(wf.nibble(), 0x5_u32); + assert_eq!(wf.high_nibble(), 0xA_u32); + + // Test builder pattern + let wf2 = TestWideFields::default() + .set_nibble(0x12345678_u32) // truncated to 0x8 + .set_high_nibble(0x9ABCDEF0_u32); // truncated to 0x0 + assert_eq!(wf2.raw(), 0x08_u8); + } } -- 2.34.1