[PATCH v17 5/7] firmware: arm_rmm: Activate the RMM

From: Suzuki K Poulose

Date: Mon Sep 07 2026 - 06:09:55 EST


From: Steven Price <steven.price@xxxxxxx>

Activate the RMM after the basic configuration. This is a memory transferring,
stateful operation.

Signed-off-by: Steven Price <steven.price@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
Changes since v16:
* Split into a new patch
---
drivers/firmware/arm_rmm/rmi.c | 17 +++++++++++++++--
include/linux/arm-rmi-cmds.h | 11 +++++++++++
2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
index 42c973c3a98bb..d969c8738efde 100644
--- a/drivers/firmware/arm_rmm/rmi.c
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -641,7 +641,8 @@ static int rmi_configure(void)

static int __init arm64_init_rmi(void)
{
- int ret;
+ int ret = 0;
+ struct rmi_sro_state *sro = NULL;

/* Continue without realm support if we can't agree on a version */
ret = rmi_check_version();
@@ -656,7 +657,19 @@ static int __init arm64_init_rmi(void)
if (ret)
return ret;

- return 0;
+ /* Activate the RMM */
+ sro = kmalloc_obj(*sro);
+ if (!sro)
+ return -ENOMEM;
+
+ ret = rmi_rmm_activate(sro);
+ if (ret) {
+ pr_err("RMM activate failed\n");
+ ret = ret < 0 ? ret : -ENXIO;
+ }
+
+ kfree(sro);
+ return ret;
}

/*
diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
index fed0f3421895d..dea7c7004d35f 100644
--- a/include/linux/arm-rmi-cmds.h
+++ b/include/linux/arm-rmi-cmds.h
@@ -64,6 +64,17 @@ static inline int rmi_rmm_config_set(unsigned long cfg_ptr)
return res.a0;
}

+/**
+ * rmi_rmm_activate() - Activate the RMM
+ * @sro: Preallocated SRO context to be used
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rmm_activate(struct rmi_sro_state *sro)
+{
+ return rmi_sro_memxfer_cmd(sro, GFP_KERNEL, SMC_RMI_RMM_ACTIVATE);
+}
+
/**
* rmi_features() - Read feature register
* @index: Feature register index
--
2.43.0