Re: [PATCH v17 1/7] firmware: arm_rmm: Add SMC definitions for calling the RMM
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: 2026-09-09 08:39:50
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kvm, kvmarm, linux-arm-kernel, lkml
On 08/09/2026 23:41, Gavin Shan wrote:
On 9/8/26 8:37 PM, Suzuki K Poulose wrote:quoted
On 08/09/2026 07:19, Gavin Shan wrote:quoted
On 9/7/26 7:59 PM, Suzuki K Poulose wrote:quoted
From: Steven Price <steven.price@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@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>...quoted
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--- include/linux/arm-smccc-rmi.h | 494 ++++++++++++++++++++++++++++++ ++++ 1 file changed, 494 insertions(+) create mode 100644 include/linux/arm-smccc-rmi.hSome nitpicks below, please pick up the commits that look reasonable :)quoted
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+ +#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.quoted
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+#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.
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+#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