Re: [PATCH v18 1/7] firmware: arm_rmm: Add SMC definitions for calling the RMM
From: Suzuki K Poulose
Date: Mon Sep 21 2026 - 06:14:45 EST
On 21/09/2026 10:27, Suzuki K Poulose wrote:
On 19/09/2026 02:27, Jonathan Cameron wrote:
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>
With Gavin's nitpicks and the GENMASK_ULL() from sashiko, just a few
comments inline. Mostly on subtle inconsistencies that really don't
matter that much.
include/linux/arm-smccc-rmi.h | 497 ++++++++++++++++++++++++++++++++++
1 file changed, 497 insertions(+)
create mode 100644 include/linux/arm-smccc-rmi.h
diff --git a/include/linux/arm-smccc-rmi.h b/include/linux/arm-smccc- rmi.h
new file mode 100644
index 000000000000..214d6228dfc2
--- /dev/null
+++ b/include/linux/arm-smccc-rmi.h
..
+
+struct rec_exit {
+ union { /* 0x000 */
+ u8 exit_reason;
+ u8 padding0[0x100];
...
+ };
+ union { /* 0x400 */
+ struct {
+ u64 cntp_ctl;
+ u64 cntp_cval;
+ u64 cntv_ctl;
+ u64 cntv_cval;
+ };
+ u8 padding4[0x100];
+ };
+ union { /* 0x500 */
+ struct {
+ u64 ripas_base;
+ u64 ripas_top;
+ u8 ripas_value;
+ u8 padding5[0xf];
In various other places you just use a u64 for a u8
+ padding. Why is this one special? And for that matter
various other fields later in this particular structure?
Please feel free to point out, if you spot any. I am happy
to fix them.
I took a look and the padding is for extra "u64" bits in there.
e.g, ripas_value offset = 0x510 and the s2ap_base is really at 0x520
not 0x518. Same applies for the pmu_ovf_status and vsmmu.
So, I would leave them as they are. The rest are consistent.
e.g, num_bps and num_wps. in realm_parameter
Cheers
Suzuki