[PATCH v3] tee: optee: build the Arm-specific code only on Arm - OP-TEE

22 Sep 2026

From: Marouene Boubakri marouene.boubakri@oss.nxp.com
The OP-TEE driver reaches OP-TEE through the SMC ABI or the FF-A ABI,
both specific to Arm, yet builds both unconditionally together with the
SMC Calling Convention definitions they rely on: ffa_abi.c is always
compiled and only its registration is conditioned on
IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT), and optee_private.h includes
<linux/arm-smccc.h> and defines the SMC and FF-A specific types for
every file of the driver. This is fine as long as the driver depends on
HAVE_ARM_SMCCC, but it keeps the driver from being built for an
architecture without SMCCC, such as RISC-V.
Build smc_abi.c only when HAVE_ARM_SMCCC is set and ffa_abi.c only when
the FF-A transport is reachable, and provide stubs for their
registration otherwise, so that it fails with -EOPNOTSUPP as the FF-A
ABI already does when the FF-A transport is not reachable. Keep the
SMCCC header, the SMC invoke function type, the SMC and FF-A specific
structures and the SMC RPC register parameters in optee_private.h under
the same conditions, and drop the unused <linux/arm-smccc.h> include
from notif.c.
The FF-A parts are keyed on IS_REACHABLE() rather than IS_ENABLED() to
preserve the behaviour of a built-in driver with a modular FF-A
transport: kbuild does not link the optee-m objects into a built-in
optee.o, so ffa_abi.c is left out exactly when the transport is not
reachable and the stubs are used instead. The IS_REACHABLE() checks in
optee_ffa_abi_register() and optee_ffa_abi_unregister() are always true
once ffa_abi.c is only compiled in that case, so drop them.
No functional change: OPTEE still depends on HAVE_ARM_SMCCC, and
ffa_abi.c is still built whenever the FF-A ABI can be registered.
Signed-off-by: Marouene Boubakri marouene.boubakri@oss.nxp.com
---
Changes in v3:
- Dropped the RPMI ABI placeholder and the RISC-V enablement patches,
  this is now a single patch (Jens).
- Key the FF-A parts of optee_private.h on IS_REACHABLE() instead of
  IS_ENABLED(): with OPTEE=y and ARM_FFA_TRANSPORT=m kbuild drops
  ffa_abi.o from the built-in optee.o while optee_ffa_abi_register()
  was still declared, which does not link.
- Drop the now always true IS_REACHABLE() checks in
  optee_ffa_abi_register() and optee_ffa_abi_unregister().
- Describe the current FF-A conditional compilation accurately in the
  commit message.
- Posted as a new thread with a proper subject prefix.
v2: https://lore.kernel.org/op-tee/20260915020235.507302-2-marouene.boubakri@oss...
Changes in v2:
- No code change, the testing section of the cover letter was completed.
v1: https://lore.kernel.org/op-tee/20260914175435.118303-2-marouene.boubakri@oss...
 drivers/tee/optee/Makefile        |  4 ++--
 drivers/tee/optee/ffa_abi.c       |  8 ++-----
 drivers/tee/optee/notif.c         |  1 -
 drivers/tee/optee/optee_private.h | 39 ++++++++++++++++++++++++++++++-
 4 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile
index ad7049c..183cdde 100644
--- a/drivers/tee/optee/Makefile
+++ b/drivers/tee/optee/Makefile
@@ -7,8 +7,8 @@ optee-objs += rpc.o
 optee-objs += protmem.o
 optee-objs += supp.o
 optee-objs += device.o
-optee-objs += smc_abi.o
-optee-objs += ffa_abi.o
+optee-$(CONFIG_HAVE_ARM_SMCCC) += smc_abi.o
+optee-$(CONFIG_ARM_FFA_TRANSPORT) += ffa_abi.o
# for tracing framework to find optee_trace.h
 CFLAGS_smc_abi.o := -I$(src)
diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
index 633715b..08236d8 100644
--- a/drivers/tee/optee/ffa_abi.c
+++ b/drivers/tee/optee/ffa_abi.c
@@ -1212,14 +1212,10 @@ static struct ffa_driver optee_ffa_driver = {
int optee_ffa_abi_register(void)
 {
-	if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
-		return ffa_register(&optee_ffa_driver);
-	else
-		return -EOPNOTSUPP;
+	return ffa_register(&optee_ffa_driver);
 }
void optee_ffa_abi_unregister(void)
 {
-	if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
-		ffa_unregister(&optee_ffa_driver);
+	ffa_unregister(&optee_ffa_driver);
 }
diff --git a/drivers/tee/optee/notif.c b/drivers/tee/optee/notif.c
index 6e85f2f..6801422 100644
--- a/drivers/tee/optee/notif.c
+++ b/drivers/tee/optee/notif.c
@@ -5,7 +5,6 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#include <linux/arm-smccc.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index aefe1e6..02d6f79 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -6,7 +6,6 @@
 #ifndef OPTEE_PRIVATE_H
 #define OPTEE_PRIVATE_H
-#include <linux/arm-smccc.h>
 #include <linux/notifier.h>
 #include <linux/rhashtable.h>
 #include <linux/rpmb.h>
@@ -15,6 +14,10 @@
 #include <linux/types.h>
 #include "optee_msg.h"
+#ifdef CONFIG_HAVE_ARM_SMCCC
+#include <linux/arm-smccc.h>
+#endif
+
 #define DRIVER_NAME "optee"
#define OPTEE_MAX_ARG_SIZE	1024
@@ -42,10 +45,12 @@
  */
 #define OPTEE_DEFAULT_MAX_NOTIF_VALUE	255
+#ifdef CONFIG_HAVE_ARM_SMCCC
 typedef void (optee_invoke_fn)(unsigned long, unsigned long, unsigned long,
    			unsigned long, unsigned long, unsigned long,
    			unsigned long, unsigned long,
    			struct arm_smccc_res *);
+#endif
/**
  * struct optee_call_waiter - TEE entry may need to wait for a free TEE thread
@@ -119,6 +124,7 @@ struct optee_supp {
    struct completion reqs_c;
 };
+#ifdef CONFIG_HAVE_ARM_SMCCC
 /**
  * struct optee_pcpu - per cpu notif private struct passed to work functions
  * @optee:	optee device reference
@@ -149,7 +155,9 @@ struct optee_smc {
    struct work_struct notif_pcpu_work;
    unsigned int notif_cpuhp_state;
 };
+#endif
+#if IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT)
 /**
  * struct optee_ffa -  FFA communication struct
  * @ffa_dev:		FFA device, contains the destination id, the id of
@@ -170,6 +178,7 @@ struct optee_ffa {
    struct workqueue_struct *notif_wq;
    struct work_struct notif_work;
 };
+#endif
struct optee;
@@ -257,8 +266,12 @@ struct optee {
    const struct optee_ops *ops;
    struct tee_context *ctx;
    union {
+#ifdef CONFIG_HAVE_ARM_SMCCC
    	struct optee_smc smc;
+#endif
+#if IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT)
    	struct optee_ffa ffa;
+#endif
    };
    struct optee_shm_arg_cache shm_arg_cache;
    struct optee_call_queue call_queue;
@@ -290,6 +303,7 @@ struct optee_context_data {
    struct list_head sess_list;
 };
+#ifdef CONFIG_HAVE_ARM_SMCCC
 struct optee_rpc_param {
    u32	a0;
    u32	a1;
@@ -300,6 +314,7 @@ struct optee_rpc_param {
    u32	a6;
    u32	a7;
 };
+#endif
/* Holds context that is preserved during one STD call */
 struct optee_call_ctx {
@@ -422,9 +437,31 @@ static inline void reg_pair_from_64(u32 *reg0, u32 *reg1, u64 val)
 }
/* Registration of the ABIs */
+#ifdef CONFIG_HAVE_ARM_SMCCC
 int optee_smc_abi_register(void);
 void optee_smc_abi_unregister(void);
+#else
+static inline int optee_smc_abi_register(void)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void optee_smc_abi_unregister(void)
+{
+}
+#endif
+#if IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT)
 int optee_ffa_abi_register(void);
 void optee_ffa_abi_unregister(void);
+#else
+static inline int optee_ffa_abi_register(void)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void optee_ffa_abi_unregister(void)
+{
+}
+#endif
#endif /*OPTEE_PRIVATE_H*/
base-commit: 827751b699b79a6e569983359c02dce67f81b94c
-- 
2.43.0


    