[PATCH v4 01/20] rust: dma: expose the count and size of CoherentAllocation

[Alexandre Courbot]

On Wed May 21, 2025 at 5:00 PM JST, Danilo Krummrich wrote:
> On Wed, May 21, 2025 at 03:44:56PM +0900, Alexandre Courbot wrote:
>> These properties are very useful to have and should be accessible.
>> 
>> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
>> ---
>>  rust/kernel/dma.rs | 18 ++++++++++++++++++
>>  1 file changed, 18 insertions(+)
>> 
>> diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs
>> index 605e01e35715667f93297fd9ec49d8e7032e0910..2a60eefa47dfc1f836c30ee342e26c6ff3e9b13a 100644
>> --- a/rust/kernel/dma.rs
>> +++ b/rust/kernel/dma.rs
>> @@ -129,6 +129,10 @@ pub mod attrs {
>>  //
>>  // Hence, find a way to revoke the device resources of a `CoherentAllocation`, but not the
>>  // entire `CoherentAllocation` including the allocated memory itself.
>> +//
>> +// # Invariants
>> +//
>> +// The size in bytes of the allocation is equal to `size_of::<T> * count()`.
>
> I think this also needs an invariant comment whenever self.count is set.

self.count appears to only be set in the constructor, added a statement
to the INVARIANT comment there.

Also noticed that my `# Invariant` section was not at the right place,
fixed that as well.