Add KUNIT tests to make sure the macro is working correctly.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
rust/kernel/bitfield.rs | 323 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 323 insertions(+)
diff --git a/rust/kernel/bitfield.rs b/rust/kernel/bitfield.rs
index 09cd5741598c..f0e341a1a979 100644
--- a/rust/kernel/bitfield.rs
+++ b/rust/kernel/bitfield.rs
@@ -329,3 +329,326 @@ fn default() -> Self {
}
};
}
+
+#[::kernel::macros::kunit_tests(kernel_bitfield)]
+mod tests {
+ use core::convert::TryFrom;
+
+ // Enum types for testing => and ?=> conversions
+ #[derive(Debug, Default, Clone, Copy, PartialEq)]
+ enum MemoryType {
+ #[default]
+ Unmapped = 0,
+ Normal = 1,
+ Device = 2,
+ Reserved = 3,
+ }
+
+ impl TryFrom<u8> for MemoryType {
+ type Error = u8;
+ fn try_from(value: u8) -> Result<Self, Self::Error> {
+ match value {
+ 0 => Ok(MemoryType::Unmapped),
+ 1 => Ok(MemoryType::Normal),
+ 2 => Ok(MemoryType::Device),
+ 3 => Ok(MemoryType::Reserved),
+ _ => Err(value),
+ }
+ }
+ }
+
+ impl From<MemoryType> for u64 {
+ fn from(mt: MemoryType) -> u64 {
+ mt as u64
+ }
+ }
+
+ #[derive(Debug, Default, Clone, Copy, PartialEq)]
+ enum Priority {
+ #[default]
+ Low = 0,
+ Medium = 1,
+ High = 2,
+ Critical = 3,
+ }
+
+ impl From<u8> for Priority {
+ fn from(value: u8) -> Self {
+ match value & 0x3 {
+ 0 => Priority::Low,
+ 1 => Priority::Medium,
+ 2 => Priority::High,
+ _ => Priority::Critical,
+ }
+ }
+ }
+
+ impl From<Priority> for u16 {
+ fn from(p: Priority) -> u16 {
+ p as u16
+ }
+ }
+
+ bitfield! {
+ struct TestPageTableEntry(u64) {
+ 0:0 present as bool;
+ 1:1 writable as bool;
+ 11:9 available as u8;
+ 13:12 mem_type as u8 ?=> MemoryType;
+ 17:14 extended_type as u8 ?=> MemoryType; // For testing failures
+ 51:12 pfn as u64;
+ 51:12 pfn_overlap as u64;
+ 61:52 available2 as u16;
+ }
+ }
+
+ bitfield! {
+ struct TestControlRegister(u16) {
+ 0:0 enable as bool;
+ 3:1 mode as u8;
+ 5:4 priority as u8 => Priority;
+ 7:4 priority_nibble as u8;
+ 15:8 channel as u8;
+ }
+ }
+
+ bitfield! {
+ struct TestStatusRegister(u8) {
+ 0:0 ready as bool;
+ 1:1 error as bool;
+ 3:2 state as u8;
+ 7:4 reserved as u8;
+ 7:0 full_byte as u8; // For entire register
+ }
+ }
+
+ #[test]
+ fn test_single_bits() {
+ let mut pte = TestPageTableEntry::default();
+
+ assert!(!pte.present());
+ assert!(!pte.writable());
+ assert_eq!(u64::from(pte), 0x0);
+
+ pte = pte.set_present(true);
+ assert!(pte.present());
+ assert_eq!(u64::from(pte), 0x1);
+
+ pte = pte.set_writable(true);
+ assert!(pte.writable());
+ assert_eq!(u64::from(pte), 0x3);
+
+ pte = pte.set_writable(false);
+ assert!(!pte.writable());
+ assert_eq!(u64::from(pte), 0x1);
+
+ assert_eq!(pte.available(), 0);
+ pte = pte.set_available(0x5);
+ assert_eq!(pte.available(), 0x5);
+ assert_eq!(u64::from(pte), 0xA01);
+ }
+
+ #[test]
+ fn test_range_fields() {
+ let mut pte = TestPageTableEntry::default();
+ assert_eq!(u64::from(pte), 0x0);
+
+ pte = pte.set_pfn(0x123456);
+ assert_eq!(pte.pfn(), 0x123456);
+ // Test overlapping field reads same value
+ assert_eq!(pte.pfn_overlap(), 0x123456);
+ assert_eq!(u64::from(pte), 0x123456000);
+
+ pte = pte.set_available(0x7);
+ assert_eq!(pte.available(), 0x7);
+ assert_eq!(u64::from(pte), 0x123456E00);
+
+ pte = pte.set_available2(0x3FF);
+ assert_eq!(pte.available2(), 0x3FF);
+ assert_eq!(u64::from(pte), 0x3FF0000123456E00);
+
+ // Test TryFrom with ?=> for MemoryType
+ pte = pte.set_mem_type(MemoryType::Device);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Device));
+ assert_eq!(u64::from(pte), 0x3FF0000123456E00);
+
+ pte = pte.set_mem_type(MemoryType::Normal);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Normal));
+ assert_eq!(u64::from(pte), 0x3FF0000123455E00);
+
+ // Test all valid values for mem_type
+ pte = pte.set_mem_type(MemoryType::Reserved);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
+ assert_eq!(u64::from(pte), 0x3FF0000123457E00);
+
+ // Test failure case using extended_type field which has 4 bits (0-15)
+ // MemoryType only handles 0-3, so values 4-15 should return Err
+ let mut raw = pte.into();
+ // Set bits 17:14 to 7 (invalid for MemoryType)
+ raw = (raw & !::kernel::bits::genmask_u64(14..=17)) | (0x7 << 14);
+ let invalid_pte = TestPageTableEntry(raw);
+ // Should return Err with the invalid value
+ assert_eq!(invalid_pte.extended_type(), Err(0x7));
+
+ // Test a valid value after testing invalid to ensure both cases work
+ // Set bits 17:14 to 2 (valid: Device)
+ raw = (raw & !::kernel::bits::genmask_u64(14..=17)) | (0x2 << 14);
+ let valid_pte = TestPageTableEntry(raw);
+ assert_eq!(valid_pte.extended_type(), Ok(MemoryType::Device));
+
+ let max_pfn = ::kernel::bits::genmask_u64(0..=39);
+ pte = pte.set_pfn(max_pfn);
+ assert_eq!(pte.pfn(), max_pfn);
+ assert_eq!(pte.pfn_overlap(), max_pfn);
+ }
+
+ #[test]
+ fn test_builder_pattern() {
+ let pte = TestPageTableEntry::default()
+ .set_present(true)
+ .set_writable(true)
+ .set_available(0x7)
+ .set_pfn(0xABCDEF)
+ .set_mem_type(MemoryType::Reserved)
+ .set_available2(0x3FF);
+
+ assert!(pte.present());
+ assert!(pte.writable());
+ assert_eq!(pte.available(), 0x7);
+ assert_eq!(pte.pfn(), 0xABCDEF);
+ assert_eq!(pte.pfn_overlap(), 0xABCDEF);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
+ assert_eq!(pte.available2(), 0x3FF);
+ }
+
+ #[test]
+ fn test_raw_operations() {
+ let raw_value = 0x3FF0000003123E03u64;
+
+ let pte = TestPageTableEntry(raw_value);
+ assert_eq!(u64::from(pte), raw_value);
+
+ assert!(pte.present());
+ assert!(pte.writable());
+ assert_eq!(pte.available(), 0x7);
+ assert_eq!(pte.pfn(), 0x3123);
+ assert_eq!(pte.pfn_overlap(), 0x3123);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
+ assert_eq!(pte.available2(), 0x3FF);
+
+ // Test using direct constructor syntax TestStruct(value)
+ let pte2 = TestPageTableEntry(raw_value);
+ assert_eq!(u64::from(pte2), raw_value);
+ }
+
+ #[test]
+ fn test_u16_bitfield() {
+ let mut ctrl = TestControlRegister::default();
+
+ assert!(!ctrl.enable());
+ assert_eq!(ctrl.mode(), 0);
+ assert_eq!(ctrl.priority(), Priority::Low);
+ assert_eq!(ctrl.priority_nibble(), 0);
+ assert_eq!(ctrl.channel(), 0);
+
+ ctrl = ctrl.set_enable(true);
+ assert!(ctrl.enable());
+
+ ctrl = ctrl.set_mode(0x5);
+ assert_eq!(ctrl.mode(), 0x5);
+
+ // Test From conversion with =>
+ ctrl = ctrl.set_priority(Priority::High);
+ assert_eq!(ctrl.priority(), Priority::High);
+ assert_eq!(ctrl.priority_nibble(), 0x2); // High = 2 in bits 5:4
+
+ ctrl = ctrl.set_channel(0xAB);
+ assert_eq!(ctrl.channel(), 0xAB);
+
+ // Test overlapping fields
+ ctrl = ctrl.set_priority_nibble(0xF);
+ assert_eq!(ctrl.priority_nibble(), 0xF);
+ assert_eq!(ctrl.priority(), Priority::Critical); // bits 5:4 = 0x3
+
+ let ctrl2 = TestControlRegister::default()
+ .set_enable(true)
+ .set_mode(0x3)
+ .set_priority(Priority::Medium)
+ .set_channel(0x42);
+
+ assert!(ctrl2.enable());
+ assert_eq!(ctrl2.mode(), 0x3);
+ assert_eq!(ctrl2.priority(), Priority::Medium);
+ assert_eq!(ctrl2.channel(), 0x42);
+
+ let raw_value: u16 = 0x4217;
+ let ctrl3 = TestControlRegister(raw_value);
+ assert_eq!(u16::from(ctrl3), raw_value);
+ assert!(ctrl3.enable());
+ assert_eq!(ctrl3.priority(), Priority::Medium);
+ assert_eq!(ctrl3.priority_nibble(), 0x1);
+ assert_eq!(ctrl3.channel(), 0x42);
+ }
+
+ #[test]
+ fn test_u8_bitfield() {
+ let mut status = TestStatusRegister::default();
+
+ assert!(!status.ready());
+ assert!(!status.error());
+ assert_eq!(status.state(), 0);
+ assert_eq!(status.reserved(), 0);
+ assert_eq!(status.full_byte(), 0);
+
+ status = status.set_ready(true);
+ assert!(status.ready());
+ assert_eq!(status.full_byte(), 0x01);
+
+ status = status.set_error(true);
+ assert!(status.error());
+ assert_eq!(status.full_byte(), 0x03);
+
+ status = status.set_state(0x3);
+ assert_eq!(status.state(), 0x3);
+ assert_eq!(status.full_byte(), 0x0F);
+
+ status = status.set_reserved(0xA);
+ assert_eq!(status.reserved(), 0xA);
+ assert_eq!(status.full_byte(), 0xAF);
+
+ // Test overlapping field
+ status = status.set_full_byte(0x55);
+ assert_eq!(status.full_byte(), 0x55);
+ assert!(status.ready());
+ assert!(!status.error());
+ assert_eq!(status.state(), 0x1);
+ assert_eq!(status.reserved(), 0x5);
+
+ let status2 = TestStatusRegister::default()
+ .set_ready(true)
+ .set_state(0x2)
+ .set_reserved(0x5);
+
+ assert!(status2.ready());
+ assert!(!status2.error());
+ assert_eq!(status2.state(), 0x2);
+ assert_eq!(status2.reserved(), 0x5);
+ assert_eq!(status2.full_byte(), 0x59);
+
+ let raw_value: u8 = 0x59;
+ let status3 = TestStatusRegister(raw_value);
+ assert_eq!(u8::from(status3), raw_value);
+ assert!(status3.ready());
+ assert!(!status3.error());
+ assert_eq!(status3.state(), 0x2);
+ assert_eq!(status3.reserved(), 0x5);
+ assert_eq!(status3.full_byte(), 0x59);
+
+ let status4 = TestStatusRegister(0xFF);
+ assert!(status4.ready());
+ assert!(status4.error());
+ assert_eq!(status4.state(), 0x3);
+ assert_eq!(status4.reserved(), 0xF);
+ assert_eq!(status4.full_byte(), 0xFF);
+ }
+}
--
2.34.1On Sat Oct 4, 2025 at 12:47 AM JST, Joel Fernandes wrote:
> Add KUNIT tests to make sure the macro is working correctly.
>
> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
> Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
> ---
> rust/kernel/bitfield.rs | 323 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 323 insertions(+)
>
> diff --git a/rust/kernel/bitfield.rs b/rust/kernel/bitfield.rs
> index 09cd5741598c..f0e341a1a979 100644
> --- a/rust/kernel/bitfield.rs
> +++ b/rust/kernel/bitfield.rs
> @@ -329,3 +329,326 @@ fn default() -> Self {
> }
> };
> }
> +
> +#[::kernel::macros::kunit_tests(kernel_bitfield)]
> +mod tests {
> + use core::convert::TryFrom;
> +
> + // Enum types for testing => and ?=> conversions
> + #[derive(Debug, Default, Clone, Copy, PartialEq)]
> + enum MemoryType {
> + #[default]
> + Unmapped = 0,
> + Normal = 1,
> + Device = 2,
> + Reserved = 3,
> + }
> +
> + impl TryFrom<u8> for MemoryType {
> + type Error = u8;
> + fn try_from(value: u8) -> Result<Self, Self::Error> {
> + match value {
> + 0 => Ok(MemoryType::Unmapped),
> + 1 => Ok(MemoryType::Normal),
> + 2 => Ok(MemoryType::Device),
> + 3 => Ok(MemoryType::Reserved),
> + _ => Err(value),
> + }
> + }
> + }
> +
> + impl From<MemoryType> for u64 {
> + fn from(mt: MemoryType) -> u64 {
> + mt as u64
> + }
> + }
> +
> + #[derive(Debug, Default, Clone, Copy, PartialEq)]
> + enum Priority {
> + #[default]
> + Low = 0,
> + Medium = 1,
> + High = 2,
> + Critical = 3,
> + }
> +
> + impl From<u8> for Priority {
> + fn from(value: u8) -> Self {
> + match value & 0x3 {
> + 0 => Priority::Low,
> + 1 => Priority::Medium,
> + 2 => Priority::High,
> + _ => Priority::Critical,
> + }
> + }
> + }
> +
> + impl From<Priority> for u16 {
> + fn from(p: Priority) -> u16 {
> + p as u16
> + }
> + }
> +
> + bitfield! {
> + struct TestPageTableEntry(u64) {
> + 0:0 present as bool;
> + 1:1 writable as bool;
> + 11:9 available as u8;
> + 13:12 mem_type as u8 ?=> MemoryType;
> + 17:14 extended_type as u8 ?=> MemoryType; // For testing failures
> + 51:12 pfn as u64;
Is the overlap with `mem_type` and `extended_type` on purpose? It looks
strange to me that the PFN also includes the memory type.
> + 51:12 pfn_overlap as u64;
If `pfn` needs to be adjusted then I guess this one also needs to be.
> + 61:52 available2 as u16;
> + }
> + }
> +
> + bitfield! {
> + struct TestControlRegister(u16) {
> + 0:0 enable as bool;
> + 3:1 mode as u8;
> + 5:4 priority as u8 => Priority;
> + 7:4 priority_nibble as u8;
> + 15:8 channel as u8;
> + }
> + }
> +
> + bitfield! {
> + struct TestStatusRegister(u8) {
> + 0:0 ready as bool;
> + 1:1 error as bool;
> + 3:2 state as u8;
> + 7:4 reserved as u8;
> + 7:0 full_byte as u8; // For entire register
> + }
> + }
> +
> + #[test]
> + fn test_single_bits() {
> + let mut pte = TestPageTableEntry::default();
> +
> + assert!(!pte.present());
> + assert!(!pte.writable());
> + assert_eq!(u64::from(pte), 0x0);
> +
> + pte = pte.set_present(true);
> + assert!(pte.present());
> + assert_eq!(u64::from(pte), 0x1);
> +
> + pte = pte.set_writable(true);
> + assert!(pte.writable());
> + assert_eq!(u64::from(pte), 0x3);
> +
> + pte = pte.set_writable(false);
> + assert!(!pte.writable());
> + assert_eq!(u64::from(pte), 0x1);
> +
> + assert_eq!(pte.available(), 0);
> + pte = pte.set_available(0x5);
> + assert_eq!(pte.available(), 0x5);
> + assert_eq!(u64::from(pte), 0xA01);
> + }
> +
> + #[test]
> + fn test_range_fields() {
> + let mut pte = TestPageTableEntry::default();
> + assert_eq!(u64::from(pte), 0x0);
> +
> + pte = pte.set_pfn(0x123456);
> + assert_eq!(pte.pfn(), 0x123456);
> + // Test overlapping field reads same value
> + assert_eq!(pte.pfn_overlap(), 0x123456);
> + assert_eq!(u64::from(pte), 0x123456000);
> +
> + pte = pte.set_available(0x7);
> + assert_eq!(pte.available(), 0x7);
> + assert_eq!(u64::from(pte), 0x123456E00);
> +
> + pte = pte.set_available2(0x3FF);
> + assert_eq!(pte.available2(), 0x3FF);
> + assert_eq!(u64::from(pte), 0x3FF0000123456E00);
> +
> + // Test TryFrom with ?=> for MemoryType
> + pte = pte.set_mem_type(MemoryType::Device);
> + assert_eq!(pte.mem_type(), Ok(MemoryType::Device));
> + assert_eq!(u64::from(pte), 0x3FF0000123456E00);
> +
> + pte = pte.set_mem_type(MemoryType::Normal);
> + assert_eq!(pte.mem_type(), Ok(MemoryType::Normal));
> + assert_eq!(u64::from(pte), 0x3FF0000123455E00);
> +
> + // Test all valid values for mem_type
> + pte = pte.set_mem_type(MemoryType::Reserved);
> + assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
> + assert_eq!(u64::from(pte), 0x3FF0000123457E00);
> +
> + // Test failure case using extended_type field which has 4 bits (0-15)
> + // MemoryType only handles 0-3, so values 4-15 should return Err
> + let mut raw = pte.into();
> + // Set bits 17:14 to 7 (invalid for MemoryType)
> + raw = (raw & !::kernel::bits::genmask_u64(14..=17)) | (0x7 << 14);
> + let invalid_pte = TestPageTableEntry(raw);
> + // Should return Err with the invalid value
> + assert_eq!(invalid_pte.extended_type(), Err(0x7));
> +
> + // Test a valid value after testing invalid to ensure both cases work
> + // Set bits 17:14 to 2 (valid: Device)
> + raw = (raw & !::kernel::bits::genmask_u64(14..=17)) | (0x2 << 14);
> + let valid_pte = TestPageTableEntry(raw);
> + assert_eq!(valid_pte.extended_type(), Ok(MemoryType::Device));
> +
> + let max_pfn = ::kernel::bits::genmask_u64(0..=39);
> + pte = pte.set_pfn(max_pfn);
> + assert_eq!(pte.pfn(), max_pfn);
> + assert_eq!(pte.pfn_overlap(), max_pfn);
> + }
> +
> + #[test]
> + fn test_builder_pattern() {
> + let pte = TestPageTableEntry::default()
> + .set_present(true)
> + .set_writable(true)
> + .set_available(0x7)
> + .set_pfn(0xABCDEF)
> + .set_mem_type(MemoryType::Reserved)
> + .set_available2(0x3FF);
> +
> + assert!(pte.present());
> + assert!(pte.writable());
> + assert_eq!(pte.available(), 0x7);
> + assert_eq!(pte.pfn(), 0xABCDEF);
> + assert_eq!(pte.pfn_overlap(), 0xABCDEF);
> + assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
> + assert_eq!(pte.available2(), 0x3FF);
Maybe check the raw value here as well, although I guess the previous
test already covered this anyway.
With these points confirmed,
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
On 10/6/2025 6:37 AM, Alexandre Courbot wrote:
> On Sat Oct 4, 2025 at 12:47 AM JST, Joel Fernandes wrote:
>> Add KUNIT tests to make sure the macro is working correctly.
>>
>> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
>> Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
>> ---
>> rust/kernel/bitfield.rs | 323 ++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 323 insertions(+)
>>
>> diff --git a/rust/kernel/bitfield.rs b/rust/kernel/bitfield.rs
>> index 09cd5741598c..f0e341a1a979 100644
>> --- a/rust/kernel/bitfield.rs
>> +++ b/rust/kernel/bitfield.rs
>> @@ -329,3 +329,326 @@ fn default() -> Self {
>> }
>> };
>> }
>> +
>> +#[::kernel::macros::kunit_tests(kernel_bitfield)]
>> +mod tests {
>> + use core::convert::TryFrom;
>> +
>> + // Enum types for testing => and ?=> conversions
>> + #[derive(Debug, Default, Clone, Copy, PartialEq)]
>> + enum MemoryType {
>> + #[default]
>> + Unmapped = 0,
>> + Normal = 1,
>> + Device = 2,
>> + Reserved = 3,
>> + }
>> +
>> + impl TryFrom<u8> for MemoryType {
>> + type Error = u8;
>> + fn try_from(value: u8) -> Result<Self, Self::Error> {
>> + match value {
>> + 0 => Ok(MemoryType::Unmapped),
>> + 1 => Ok(MemoryType::Normal),
>> + 2 => Ok(MemoryType::Device),
>> + 3 => Ok(MemoryType::Reserved),
>> + _ => Err(value),
>> + }
>> + }
>> + }
>> +
>> + impl From<MemoryType> for u64 {
>> + fn from(mt: MemoryType) -> u64 {
>> + mt as u64
>> + }
>> + }
>> +
>> + #[derive(Debug, Default, Clone, Copy, PartialEq)]
>> + enum Priority {
>> + #[default]
>> + Low = 0,
>> + Medium = 1,
>> + High = 2,
>> + Critical = 3,
>> + }
>> +
>> + impl From<u8> for Priority {
>> + fn from(value: u8) -> Self {
>> + match value & 0x3 {
>> + 0 => Priority::Low,
>> + 1 => Priority::Medium,
>> + 2 => Priority::High,
>> + _ => Priority::Critical,
>> + }
>> + }
>> + }
>> +
>> + impl From<Priority> for u16 {
>> + fn from(p: Priority) -> u16 {
>> + p as u16
>> + }
>> + }
>> +
>> + bitfield! {
>> + struct TestPageTableEntry(u64) {
>> + 0:0 present as bool;
>> + 1:1 writable as bool;
>> + 11:9 available as u8;
>> + 13:12 mem_type as u8 ?=> MemoryType;
>> + 17:14 extended_type as u8 ?=> MemoryType; // For testing failures
>> + 51:12 pfn as u64;
>
> Is the overlap with `mem_type` and `extended_type` on purpose?
Yes, here I was testing the failure mode of ?=> without having to introduce a
new enum type. But I could just do so with mem_type by adding more bits to it,
so I'll do that and remove extended_type.
> It looks strange to me that the PFN also includes the memory type.
I agree with this (even though these structs are just approximately accurate and
for testing purposes). Since we're testing overlap already in later tests, I
will just remove it from this test.
Following is the new struct now, hope it looks ok:
bitfield! {
struct TestPageTableEntry(u64) {
0:0 present as bool;
1:1 writable as bool;
11:9 available as u8;
15:12 mem_type as u8 ?=> MemoryType;
51:16 pfn as u64;
61:52 available2 as u16;
}
}
>> + 51:12 pfn_overlap as u64;
>
> If `pfn` needs to be adjusted then I guess this one also needs to be.
>
>> + 61:52 available2 as u16;
>> + }
>> + }
>> +
>> + bitfield! {
>> + struct TestControlRegister(u16) {
>> + 0:0 enable as bool;
>> + 3:1 mode as u8;
>> + 5:4 priority as u8 => Priority;
>> + 7:4 priority_nibble as u8;
>> + 15:8 channel as u8;
>> + }
>> + }
>> +
>> + bitfield! {
>> + struct TestStatusRegister(u8) {
>> + 0:0 ready as bool;
>> + 1:1 error as bool;
>> + 3:2 state as u8;
>> + 7:4 reserved as u8;
>> + 7:0 full_byte as u8; // For entire register
>> + }
>> + }
>> +
>> + #[test]
>> + fn test_single_bits() {
>> + let mut pte = TestPageTableEntry::default();
>> +
>> + assert!(!pte.present());
>> + assert!(!pte.writable());
>> + assert_eq!(u64::from(pte), 0x0);
>> +
>> + pte = pte.set_present(true);
>> + assert!(pte.present());
>> + assert_eq!(u64::from(pte), 0x1);
>> +
>> + pte = pte.set_writable(true);
>> + assert!(pte.writable());
>> + assert_eq!(u64::from(pte), 0x3);
>> +
>> + pte = pte.set_writable(false);
>> + assert!(!pte.writable());
>> + assert_eq!(u64::from(pte), 0x1);
>> +
>> + assert_eq!(pte.available(), 0);
>> + pte = pte.set_available(0x5);
>> + assert_eq!(pte.available(), 0x5);
>> + assert_eq!(u64::from(pte), 0xA01);
>> + }
>> +
>> + #[test]
>> + fn test_range_fields() {
>> + let mut pte = TestPageTableEntry::default();
>> + assert_eq!(u64::from(pte), 0x0);
>> +
>> + pte = pte.set_pfn(0x123456);
>> + assert_eq!(pte.pfn(), 0x123456);
>> + // Test overlapping field reads same value
>> + assert_eq!(pte.pfn_overlap(), 0x123456);
>> + assert_eq!(u64::from(pte), 0x123456000);
>> +
>> + pte = pte.set_available(0x7);
>> + assert_eq!(pte.available(), 0x7);
>> + assert_eq!(u64::from(pte), 0x123456E00);
>> +
>> + pte = pte.set_available2(0x3FF);
>> + assert_eq!(pte.available2(), 0x3FF);
>> + assert_eq!(u64::from(pte), 0x3FF0000123456E00);
>> +
>> + // Test TryFrom with ?=> for MemoryType
>> + pte = pte.set_mem_type(MemoryType::Device);
>> + assert_eq!(pte.mem_type(), Ok(MemoryType::Device));
>> + assert_eq!(u64::from(pte), 0x3FF0000123456E00);
>> +
>> + pte = pte.set_mem_type(MemoryType::Normal);
>> + assert_eq!(pte.mem_type(), Ok(MemoryType::Normal));
>> + assert_eq!(u64::from(pte), 0x3FF0000123455E00);
>> +
>> + // Test all valid values for mem_type
>> + pte = pte.set_mem_type(MemoryType::Reserved);
>> + assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
>> + assert_eq!(u64::from(pte), 0x3FF0000123457E00);
>> +
>> + // Test failure case using extended_type field which has 4 bits (0-15)
>> + // MemoryType only handles 0-3, so values 4-15 should return Err
>> + let mut raw = pte.into();
>> + // Set bits 17:14 to 7 (invalid for MemoryType)
>> + raw = (raw & !::kernel::bits::genmask_u64(14..=17)) | (0x7 << 14);
>> + let invalid_pte = TestPageTableEntry(raw);
>> + // Should return Err with the invalid value
>> + assert_eq!(invalid_pte.extended_type(), Err(0x7));
>> +
>> + // Test a valid value after testing invalid to ensure both cases work
>> + // Set bits 17:14 to 2 (valid: Device)
>> + raw = (raw & !::kernel::bits::genmask_u64(14..=17)) | (0x2 << 14);
>> + let valid_pte = TestPageTableEntry(raw);
>> + assert_eq!(valid_pte.extended_type(), Ok(MemoryType::Device));
>> +
>> + let max_pfn = ::kernel::bits::genmask_u64(0..=39);
>> + pte = pte.set_pfn(max_pfn);
>> + assert_eq!(pte.pfn(), max_pfn);
>> + assert_eq!(pte.pfn_overlap(), max_pfn);
>> + }
>> +
>> + #[test]
>> + fn test_builder_pattern() {
>> + let pte = TestPageTableEntry::default()
>> + .set_present(true)
>> + .set_writable(true)
>> + .set_available(0x7)
>> + .set_pfn(0xABCDEF)
>> + .set_mem_type(MemoryType::Reserved)
>> + .set_available2(0x3FF);
>> +
>> + assert!(pte.present());
>> + assert!(pte.writable());
>> + assert_eq!(pte.available(), 0x7);
>> + assert_eq!(pte.pfn(), 0xABCDEF);
>> + assert_eq!(pte.pfn_overlap(), 0xABCDEF);
>> + assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
>> + assert_eq!(pte.available2(), 0x3FF);
>
> Maybe check the raw value here as well, although I guess the previous
> test already covered this anyway.
>
> With these points confirmed,
>
> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Thanks! I will resend just this patch as a reply-to this patch (hope that's Ok).
- Joel
Add KUNIT tests to make sure the macro is working correctly.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
rust/kernel/bitfield.rs | 316 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 316 insertions(+)
diff --git a/rust/kernel/bitfield.rs b/rust/kernel/bitfield.rs
index 09cd5741598c..c3e0ef531256 100644
--- a/rust/kernel/bitfield.rs
+++ b/rust/kernel/bitfield.rs
@@ -329,3 +329,319 @@ fn default() -> Self {
}
};
}
+
+#[::kernel::macros::kunit_tests(kernel_bitfield)]
+mod tests {
+ use core::convert::TryFrom;
+
+ // Enum types for testing => and ?=> conversions
+ #[derive(Debug, Default, Clone, Copy, PartialEq)]
+ enum MemoryType {
+ #[default]
+ Unmapped = 0,
+ Normal = 1,
+ Device = 2,
+ Reserved = 3,
+ }
+
+ impl TryFrom<u8> for MemoryType {
+ type Error = u8;
+ fn try_from(value: u8) -> Result<Self, Self::Error> {
+ match value {
+ 0 => Ok(MemoryType::Unmapped),
+ 1 => Ok(MemoryType::Normal),
+ 2 => Ok(MemoryType::Device),
+ 3 => Ok(MemoryType::Reserved),
+ _ => Err(value),
+ }
+ }
+ }
+
+ impl From<MemoryType> for u64 {
+ fn from(mt: MemoryType) -> u64 {
+ mt as u64
+ }
+ }
+
+ #[derive(Debug, Default, Clone, Copy, PartialEq)]
+ enum Priority {
+ #[default]
+ Low = 0,
+ Medium = 1,
+ High = 2,
+ Critical = 3,
+ }
+
+ impl From<u8> for Priority {
+ fn from(value: u8) -> Self {
+ match value & 0x3 {
+ 0 => Priority::Low,
+ 1 => Priority::Medium,
+ 2 => Priority::High,
+ _ => Priority::Critical,
+ }
+ }
+ }
+
+ impl From<Priority> for u16 {
+ fn from(p: Priority) -> u16 {
+ p as u16
+ }
+ }
+
+ bitfield! {
+ struct TestPageTableEntry(u64) {
+ 0:0 present as bool;
+ 1:1 writable as bool;
+ 11:9 available as u8;
+ 15:12 mem_type as u8 ?=> MemoryType;
+ 51:16 pfn as u64;
+ 61:52 available2 as u16;
+ }
+ }
+
+ bitfield! {
+ struct TestControlRegister(u16) {
+ 0:0 enable as bool;
+ 3:1 mode as u8;
+ 5:4 priority as u8 => Priority;
+ 7:4 priority_nibble as u8;
+ 15:8 channel as u8;
+ }
+ }
+
+ bitfield! {
+ struct TestStatusRegister(u8) {
+ 0:0 ready as bool;
+ 1:1 error as bool;
+ 3:2 state as u8;
+ 7:4 reserved as u8;
+ 7:0 full_byte as u8; // For entire register
+ }
+ }
+
+ #[test]
+ fn test_single_bits() {
+ let mut pte = TestPageTableEntry::default();
+
+ assert!(!pte.present());
+ assert!(!pte.writable());
+ assert_eq!(u64::from(pte), 0x0);
+
+ pte = pte.set_present(true);
+ assert!(pte.present());
+ assert_eq!(u64::from(pte), 0x1);
+
+ pte = pte.set_writable(true);
+ assert!(pte.writable());
+ assert_eq!(u64::from(pte), 0x3);
+
+ pte = pte.set_writable(false);
+ assert!(!pte.writable());
+ assert_eq!(u64::from(pte), 0x1);
+
+ assert_eq!(pte.available(), 0);
+ pte = pte.set_available(0x5);
+ assert_eq!(pte.available(), 0x5);
+ assert_eq!(u64::from(pte), 0xA01);
+ }
+
+ #[test]
+ fn test_range_fields() {
+ let mut pte = TestPageTableEntry::default();
+ assert_eq!(u64::from(pte), 0x0);
+
+ pte = pte.set_pfn(0x123456);
+ assert_eq!(pte.pfn(), 0x123456);
+ assert_eq!(u64::from(pte), 0x1234560000);
+
+ pte = pte.set_available(0x7);
+ assert_eq!(pte.available(), 0x7);
+ assert_eq!(u64::from(pte), 0x1234560E00);
+
+ pte = pte.set_available2(0x3FF);
+ assert_eq!(pte.available2(), 0x3FF);
+ assert_eq!(u64::from(pte), 0x3FF0_0012_3456_0E00u64);
+
+ // Test TryFrom with ?=> for MemoryType
+ pte = pte.set_mem_type(MemoryType::Device);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Device));
+ assert_eq!(u64::from(pte), 0x3FF0_0012_3456_2E00u64);
+
+ pte = pte.set_mem_type(MemoryType::Normal);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Normal));
+ assert_eq!(u64::from(pte), 0x3FF0_0012_3456_1E00u64);
+
+ // Test all valid values for mem_type
+ pte = pte.set_mem_type(MemoryType::Reserved);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
+ assert_eq!(u64::from(pte), 0x3FF0_0012_3456_3E00u64);
+
+ // Test failure case using mem_type field which has 4 bits (0-15)
+ // MemoryType only handles 0-3, so values 4-15 should return Err
+ let mut raw = pte.into();
+ // Set bits 15:12 to 7 (invalid for MemoryType)
+ raw = (raw & !::kernel::bits::genmask_u64(12..=15)) | (0x7 << 12);
+ let invalid_pte = TestPageTableEntry(raw);
+ // Should return Err with the invalid value
+ assert_eq!(invalid_pte.mem_type(), Err(0x7));
+
+ // Test a valid value after testing invalid to ensure both cases work
+ // Set bits 15:12 to 2 (valid: Device)
+ raw = (raw & !::kernel::bits::genmask_u64(12..=15)) | (0x2 << 12);
+ let valid_pte = TestPageTableEntry(raw);
+ assert_eq!(valid_pte.mem_type(), Ok(MemoryType::Device));
+
+ let max_pfn = ::kernel::bits::genmask_u64(0..=35);
+ pte = pte.set_pfn(max_pfn);
+ assert_eq!(pte.pfn(), max_pfn);
+ }
+
+ #[test]
+ fn test_builder_pattern() {
+ let pte = TestPageTableEntry::default()
+ .set_present(true)
+ .set_writable(true)
+ .set_available(0x7)
+ .set_pfn(0xABCDEF)
+ .set_mem_type(MemoryType::Reserved)
+ .set_available2(0x3FF);
+
+ assert!(pte.present());
+ assert!(pte.writable());
+ assert_eq!(pte.available(), 0x7);
+ assert_eq!(pte.pfn(), 0xABCDEF);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
+ assert_eq!(pte.available2(), 0x3FF);
+ }
+
+ #[test]
+ fn test_raw_operations() {
+ let raw_value = 0x3FF0000031233E03u64;
+
+ let pte = TestPageTableEntry(raw_value);
+ assert_eq!(u64::from(pte), raw_value);
+
+ assert!(pte.present());
+ assert!(pte.writable());
+ assert_eq!(pte.available(), 0x7);
+ assert_eq!(pte.pfn(), 0x3123);
+ assert_eq!(pte.mem_type(), Ok(MemoryType::Reserved));
+ assert_eq!(pte.available2(), 0x3FF);
+
+ // Test using direct constructor syntax TestStruct(value)
+ let pte2 = TestPageTableEntry(raw_value);
+ assert_eq!(u64::from(pte2), raw_value);
+ }
+
+ #[test]
+ fn test_u16_bitfield() {
+ let mut ctrl = TestControlRegister::default();
+
+ assert!(!ctrl.enable());
+ assert_eq!(ctrl.mode(), 0);
+ assert_eq!(ctrl.priority(), Priority::Low);
+ assert_eq!(ctrl.priority_nibble(), 0);
+ assert_eq!(ctrl.channel(), 0);
+
+ ctrl = ctrl.set_enable(true);
+ assert!(ctrl.enable());
+
+ ctrl = ctrl.set_mode(0x5);
+ assert_eq!(ctrl.mode(), 0x5);
+
+ // Test From conversion with =>
+ ctrl = ctrl.set_priority(Priority::High);
+ assert_eq!(ctrl.priority(), Priority::High);
+ assert_eq!(ctrl.priority_nibble(), 0x2); // High = 2 in bits 5:4
+
+ ctrl = ctrl.set_channel(0xAB);
+ assert_eq!(ctrl.channel(), 0xAB);
+
+ // Test overlapping fields
+ ctrl = ctrl.set_priority_nibble(0xF);
+ assert_eq!(ctrl.priority_nibble(), 0xF);
+ assert_eq!(ctrl.priority(), Priority::Critical); // bits 5:4 = 0x3
+
+ let ctrl2 = TestControlRegister::default()
+ .set_enable(true)
+ .set_mode(0x3)
+ .set_priority(Priority::Medium)
+ .set_channel(0x42);
+
+ assert!(ctrl2.enable());
+ assert_eq!(ctrl2.mode(), 0x3);
+ assert_eq!(ctrl2.priority(), Priority::Medium);
+ assert_eq!(ctrl2.channel(), 0x42);
+
+ let raw_value: u16 = 0x4217;
+ let ctrl3 = TestControlRegister(raw_value);
+ assert_eq!(u16::from(ctrl3), raw_value);
+ assert!(ctrl3.enable());
+ assert_eq!(ctrl3.priority(), Priority::Medium);
+ assert_eq!(ctrl3.priority_nibble(), 0x1);
+ assert_eq!(ctrl3.channel(), 0x42);
+ }
+
+ #[test]
+ fn test_u8_bitfield() {
+ let mut status = TestStatusRegister::default();
+
+ assert!(!status.ready());
+ assert!(!status.error());
+ assert_eq!(status.state(), 0);
+ assert_eq!(status.reserved(), 0);
+ assert_eq!(status.full_byte(), 0);
+
+ status = status.set_ready(true);
+ assert!(status.ready());
+ assert_eq!(status.full_byte(), 0x01);
+
+ status = status.set_error(true);
+ assert!(status.error());
+ assert_eq!(status.full_byte(), 0x03);
+
+ status = status.set_state(0x3);
+ assert_eq!(status.state(), 0x3);
+ assert_eq!(status.full_byte(), 0x0F);
+
+ status = status.set_reserved(0xA);
+ assert_eq!(status.reserved(), 0xA);
+ assert_eq!(status.full_byte(), 0xAF);
+
+ // Test overlapping field
+ status = status.set_full_byte(0x55);
+ assert_eq!(status.full_byte(), 0x55);
+ assert!(status.ready());
+ assert!(!status.error());
+ assert_eq!(status.state(), 0x1);
+ assert_eq!(status.reserved(), 0x5);
+
+ let status2 = TestStatusRegister::default()
+ .set_ready(true)
+ .set_state(0x2)
+ .set_reserved(0x5);
+
+ assert!(status2.ready());
+ assert!(!status2.error());
+ assert_eq!(status2.state(), 0x2);
+ assert_eq!(status2.reserved(), 0x5);
+ assert_eq!(status2.full_byte(), 0x59);
+
+ let raw_value: u8 = 0x59;
+ let status3 = TestStatusRegister(raw_value);
+ assert_eq!(u8::from(status3), raw_value);
+ assert!(status3.ready());
+ assert!(!status3.error());
+ assert_eq!(status3.state(), 0x2);
+ assert_eq!(status3.reserved(), 0x5);
+ assert_eq!(status3.full_byte(), 0x59);
+
+ let status4 = TestStatusRegister(0xFF);
+ assert!(status4.ready());
+ assert!(status4.error());
+ assert_eq!(status4.state(), 0x3);
+ assert_eq!(status4.reserved(), 0xF);
+ assert_eq!(status4.full_byte(), 0xFF);
+ }
+}
--
2.34.1© 2016 - 2025 Red Hat, Inc.