[PATCH v17 1/7] firmware: arm_rmm: Add SMC definitions for calling the RMM
Suzuki K Poulose
suzuki.poulose at arm.com
Wed Sep 9 01:39:45 PDT 2026
On 08/09/2026 23:41, Gavin Shan wrote:
> On 9/8/26 8:37 PM, Suzuki K Poulose wrote:
>> On 08/09/2026 07:19, Gavin Shan wrote:
>>> On 9/7/26 7:59 PM, Suzuki K Poulose wrote:
>>>> From: Steven Price <steven.price at arm.com>
>>>>
>>>> The RMM (Realm Management Monitor) provides functionality that can be
>>>> accessed by SMC calls from the host.
>>>>
>>>> The SMC definitions are based on DEN0137[1] version 2.0-bet3
>>>>
>>>> [1] https://developer.arm.com/documentation/den0137/2-0bet3/
>>>>
>>>> Signed-off-by: Steven Price <steven.price at arm.com>
>>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>
>>
>> ...
>>
>>>> ---
>>>> include/linux/arm-smccc-rmi.h | 494 ++++++++++++++++++++++++++++++
>>>> ++++
>>>> 1 file changed, 494 insertions(+)
>>>> create mode 100644 include/linux/arm-smccc-rmi.h
>>>>
>>>
>>> Some nitpicks below, please pick up the commits that look reasonable :)
>>>
>>
>>
>>>> +
>>>> +#define RMI_RETURN_STATUS_MASK (0xFFUL)
>>>> +#define RMI_RETURN_INDEX_MASK (0xFFUL << 8)
>>>> +#define RMI_RETURN_MEMREQ_MASK (0x3UL << 8)
>>>> +#define RMI_RETURN_CAN_CANCEL_MASK (0x1UL << 10)
>>>> +
>>>> +#define RMI_RETURN_STATUS(ret) FIELD_GET(RMI_RETURN_STATUS_MASK, ret)
>>>> +#define RMI_RETURN_INDEX(ret)
>>>> FIELD_GET(RMI_RETURN_INDEX_MASK, ret)
>>>> +#define RMI_RETURN_MEMREQ(ret) FIELD_GET(RMI_RETURN_MEMREQ_MASK, ret)
>>>> +#define RMI_RETURN_CAN_CANCEL(ret)
>>>> FIELD_GET(RMI_RETURN_CAN_CANCEL_MASK, ret)
>>>> +
>>>
>>> If I'm correct enough, RMI_RETURN_{STATUS, INDEX, MEMREQ, CAN_CANEL}
>>> _MASK are used
>>> for once in this header file. So we needn't explicitly expose them
>>> and combine their
>>> definitions with users to fetch the corresponding fields, as below.
>>>
>>> #define RMI_RETURN_STATUS(ret) FIELD_GET(GENMASK(7, 0), ret)
>>> #define RMI_RETURN_INDEX(ret) FIELD_GET(GENMASK(15, 8), ret)
>>> #define RMI_RETURN_MEMREQ(ret) FIELD_GET(GENMASK(10, 8), ret)
>>> #define RMI_RETURN_CAN_CANCEL(ret) FIELD_GEt(GENMASK(10, 10), ret)
>>
>> I belive the header files were generated from a tool (by Steven) and
>> these would make it easier to compare with the generated header file for
>> any deviation from the spec. So, I am a bit reluctant make these
>> changes.
>>
>> That said, I am happy to convert the mask definitions to GENMASK() for
>> consistency and readability. i.e., something like:
>>
>> diff --git a/include/linux/arm-smccc-rmi.h b/include/linux/arm-smccc-
>> rmi.h
>> index 3eb88caf40964..078197284415e 100644
>> --- a/include/linux/arm-smccc-rmi.h
>> +++ b/include/linux/arm-smccc-rmi.h
>> @@ -139,10 +139,10 @@
>> #define RMI_ABI_VERSION_GET_MINOR(version) ((version) & 0xFFFF)
>> #define RMI_ABI_VERSION(major, minor) (((major) << 16) | (minor))
>>
>> -#define RMI_RETURN_STATUS_MASK (0xFFUL)
>> -#define RMI_RETURN_INDEX_MASK (0xFFUL << 8)
>> -#define RMI_RETURN_MEMREQ_MASK (0x3UL << 8)
>> -#define RMI_RETURN_CAN_CANCEL_MASK (0x1UL << 10)
>> +#define RMI_RETURN_STATUS_MASK GENMASK(7, 0)
>> +#define RMI_RETURN_INDEX_MASK GENMASK(15, 8)
>> +#define RMI_RETURN_MEMREQ_MASK GENMASK(10, 8)
>> +#define RMI_RETURN_CAN_CANCEL_MASK BIT(10)
>>
>
> Ok.
>
>>>
>>>> +#define RMI_SUCCESS 0
>>>> +#define RMI_ERROR_INPUT 1
>>>> +#define RMI_ERROR_REALM 2
>>>> +#define RMI_ERROR_REC 3
>>>> +#define RMI_ERROR_RTT 4
>>>> +#define RMI_ERROR_NOT_SUPPORTED 5
>>>> +#define RMI_ERROR_DEVICE 6
>>>> +#define RMI_ERROR_RTT_AUX 7
>>>> +#define RMI_ERROR_PSMMU_ST 8
>>>> +#define RMI_ERROR_DPT 9
>>>> +#define RMI_BUSY 10
>>>> +#define RMI_ERROR_GLOBAL 11
>>>> +#define RMI_ERROR_TRACKING 12
>>>> +#define RMI_INCOMPLETE 13
>>>> +#define RMI_BLOCKED 14
>>>> +#define RMI_ERROR_GPT 15
>>>> +#define RMI_ERROR_GRANULE 16
>>>> +
>>>> +#define RMI_CONTINUE_KEEP_GOING 0
>>>> +#define RMI_CONTINUE_STOP 1
>>>> +
>>>> +#define RMI_OP_MEM_REQ_NONE 0
>>>> +#define RMI_OP_MEM_REQ_DONATE 1
>>>> +#define RMI_OP_MEM_REQ_RECLAIM 2
>>>> +
>>>> +#define RMI_DONATE_SIZE_MASK 3UL
>>>> +#define RMI_DONATE_COUNT_MASK GENMASK(15, 2)
>>>> +#define RMI_DONATE_CONTIG_MASK BIT(16)
>>>> +#define RMI_DONATE_STATE_MASK GENMASK(18, 17)
>>>> +
>>>> +#define RMI_DONATE_SIZE(req) FIELD_GET(RMI_DONATE_SIZE_MASK,
>>>> req)
>>>> +#define RMI_DONATE_COUNT(req)
>>>> FIELD_GET(RMI_DONATE_COUNT_MASK, req)
>>>> +#define RMI_DONATE_CONTIG(req) FIELD_GET(RMI_DONATE_CONTIG_MASK, req)
>>>> +#define RMI_DONATE_STATE(req)
>>>> FIELD_GET(RMI_DONATE_STATE_MASK, req)
>>>> +
>>>
>>> As above, RMI_DONATE_{SIZE, COUNT, CONTIG, STATE}_MASK are used for
>>> once in this
>>> header file. So their definitions can be dropped by modifying the
>>> followup macros,
>>> as below. Some enhancements are also applicable: (a) Use 'BLOCK' to
>>> indicate the
>>> unit encoded in the request. (b) The macros are put into order from
>>> MSB to LSB.
>>>
>>> #define RMI_DONATE_STATE(req) FIELD_GET(GENMASK(18, 17), req)
>>> #define RMI_DONATE_CONTIG(req) FIELD_GET(GENMASK(16, 16), req)
>>> #define RMI_DONATE_BLOCK_COUNT(req) FIELD_GET(GENMASK(15, 2), req)
>>> #define RMI_DONATE_BLOCK_SIZE(req) FIELD_GET(GENMASK(1, 0), req)
>>
>> Same as above.
>>
>
> Please rename RMI_DONATE_{SIZE, COUNT} to RMI_DONATE_BLOCK_{SIZE, COUNT}
> if possible.
Sorry, forgot to add that, I have renamed RMI_{DONATE,ADDR_RANGE}_SIZE
=> RMI_{*}_BLOCK_SIZE, left the _COUNT as it is.
>
>>>
>>>> +#define RMI_OP_MEM_DELEGATED 0
>>>> +#define RMI_OP_MEM_UNDELEGATED 1
>>>> +#define RMI_OP_MEM_CONDITIONAL 2
>>>> +
>>>
>>> B4.6.40 RmiOpMemContig type is missed here and they should be used in
>>> the c code.
>>>
>>> #define RMI_OP_MEM_NON_CONTIG 0
>>> #define RMI_OP_MEM_CONTIG 1
>>>
>>> In the c code, we shall have:
>>>
>>> if (RMI_DONATE_CONTIG(req) == RMI_OP_MEM_CONTIG)) {
>>> ...
>>> } else {
>>> ...
>>> }
>>>
>>
>> Does it make much sense though ? I prefer
>>
>> if (RMI_DONATE_CONTIG(req))
>>
>> to
>>
>>
>> if (RMI_DONATE_CONTIG(req) == RMI_OP_MEM_CONTIG)) {
>>
>>
>> than having a field for a single bit values. I am happy to change
>> this if there is strong preference to the other.
>>
>
> The point is RMM-v2.0-bet3 expose RMI_OP_{MEM, MEM_NON}_CONTIG instead
> of true/false
> to indicate if the requested memory blocks are physically contiguous or
> not. So the
> expression 'if (RMI_DONATE_CONTIG(req) == RMI_OP_MEM_CONTIG)' is
> consistent to the
> RMM-v2.0-bet3 spec.
Agree, but the values are intuitively assigned to indicate whether it is
1/0. I personally think if (RMI_DONATE_CONTIG(req)) is good enough. But
to be consistent with the spec, I will change them.
Cheers
Suzuki
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