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

On 10/09/2026 10:47, Gavin Shan wrote:

On 9/9/26 6:39 PM, Suzuki K Poulose wrote:

quoted

On 08/09/2026 23:41, Gavin Shan wrote:

quoted

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

quoted

---
  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 :)

quoted

quoted

+
+#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

quoted

quoted

+#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.

It's ok to me. The point is to have "BLOCK", indicating it's related to
a block. In rmi.c, 'unit' is also used and needs to be replaced with 
'block',
consistent with the spec.

Yep, I could see why Steven went with "unit". But I have replaced them
with block everywhere to be consistent with the spec.

Cheers
Suzuki