Re: [PATCH v17 1/7] firmware: arm_rmm: Add SMC definitions for calling the RMM

From: Gavin Shan

Date: Tue Sep 08 2026 - 18:44:56 EST


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@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>

...

---
  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.


+#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.

Similarly, B4.6.39 RmiOpCanCancel type is missed here and they should be used in
the c code.

#define RMI_OP_CANNOT_CANCEL    0
#define RMI_OP_CAN_CANCEL    1

In the c code, we shall have:

if (RMI_RETURN_CAN_CANCEL(ret) == RMI_OP_CAN_CANCEL) {
     ...
} else {
     ...
}


Same as above.


Please see above explanation.

+#define RMI_ADDR_TYPE_NONE        0
+#define RMI_ADDR_TYPE_SINGLE        1
+#define RMI_ADDR_TYPE_LIST        2
+
+#define RMI_ADDR_RANGE_SIZE_MASK    GENMASK(1, 0)
+#define RMI_ADDR_RANGE_COUNT_MASK    GENMASK(PAGE_SHIFT - 1, 2)
+#define RMI_ADDR_RANGE_ADDR_MASK    (PAGE_MASK & GENMASK(51, 0))
+#define RMI_ADDR_RANGE_STATE_MASK    GENMASK(63, 62)
+
+#define RMI_ADDR_RANGE_SIZE(ar) (FIELD_GET(RMI_ADDR_RANGE_SIZE_MASK, \
+                           (ar)))
+#define RMI_ADDR_RANGE_COUNT(ar) (FIELD_GET(RMI_ADDR_RANGE_COUNT_MASK, \
+                           (ar)))
+#define RMI_ADDR_RANGE_ADDR(ar)        ((ar) & RMI_ADDR_RANGE_ADDR_MASK)
+#define RMI_ADDR_RANGE_STATE(ar) (FIELD_GET(RMI_ADDR_RANGE_STATE_MASK, \
+                           (ar)))
+

I guess it wouldn't a bad idea to explictly indicate 'BLOCK' in the definitions, as
below. Some improvements are applicated either: (a) 'ar' is renamed to 'r'; (b) The
excessive parentheses are dropped to follow the patterns we already had; (c) For
RMI_ADDR_RANGE_ADDR(r), FIELD_GET() is used.

#define RMI_ADDR_RANGE_BLOCK_SIZE_MASK        GENMASK(1, 0)
#define RMI_ADDR_RANGE_BLOCK_COUNT_MASK        GENMASK(PAGE_SHIFT - 1, 2)
#define RMI_ADDR_RANGE_ADDR_MASK        (PAGE_MASK & GENMASK(51, 0))
#define RMI_ADDR_RANGE_STATE_MASK        GENMASK(63, 62)

#define RMI_ADDR_RANGE_BLOCK_SIZE(r) FIELD_GET(RMI_ADDR_RANGE_SIZE_MASK, r)
#define RMI_ADDR_RANGE_BLOCK_COUNT(r) FIELD_GET(RMI_ADDR_RANGE_COUNT_MASK, r)
#define RMI_ADDR_RANGE_ADDR(r) FIELD_GET(RMI_ADDR_RANGE_ADDR_MASK, r)
#define RMI_ADDR_RANGE_STATE(r) FIELD_GET(RMI_ADDR_RANGE_STATE_MASK, r)

Ack


+enum rmi_ripas {
+    RMI_EMPTY = 0,
+    RMI_RAM = 1,
+    RMI_DESTROYED = 2,
+    RMI_DEV = 3,
+};

+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_4KB    BIT(0)
+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_16KB    BIT(1)
+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_64KB    BIT(2)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_256    BIT(3)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_384    BIT(4)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_512    BIT(5)
+#define RMI_FEATURE_REGISTER_1_MAX_RECS_ORDER    GENMASK(9, 6)
+#define RMI_FEATURE_REGISTER_1_L0GPTSZ        GENMASK(13, 10)
+#define RMI_FEATURE_REGISTER_1_PPS        GENMASK(16, 14)
+
+#define RMI_FEATURE_REGISTER_2_DA        BIT(0)
+#define RMI_FEATURE_REGISTER_2_DA_COH        BIT(1)
+#define RMI_FEATURE_REGISTER_2_VSMMU        BIT(2)
+#define RMI_FEATURE_REGISTER_2_ATS        BIT(3)
+#define RMI_FEATURE_REGISTER_2_PDEV_MAX_VDEVS_ORDER    GENMASK(7, 4)
+#define RMI_FEATURE_REGISTER_2_VDEV_KROU    BIT(8)
+#define RMI_FEATURE_REGISTER_2_NON_TEE_STREAM    BIT(9)
+#define RMI_FEATURE_REGISTER_2_REALM_MAX_VDEVS_ORDER    GENMASK(14, 10)
+
+#define RMI_FEATURE_REGISTER_3_MAX_NUM_AUX_PLANES    GENMASK(3, 0)
+#define RMI_FEATURE_REGISTER_3_RTT_PLANE        GENMASK(5, 4)
+#define RMI_FEATURE_REGISTER_3_RTT_S2AP_INDIRECT    BIT(6)
+
+#define RMI_FEATURE_REGISTER_4_MEC_COUNT        GENMASK(63, 0)
+

We would reorder those feature register definitions from MSB ro LSB :-)

Ack

Thanks for your review.

Cheers
Suzuki


Thanks,
Gavin