[PATCH] iommu: fix ARM_SMMU vs QCOM_SCM compilation

[Dmitry Baryshkov]

After commit 424953cf3c66 ("qcom_scm: hide Kconfig symbol") arm-smmu got
qcom_smmu_impl_init() call guarded by IS_ENABLED(CONFIG_ARM_SMMU_QCOM).
However the CONFIG_ARM_SMMU_QCOM Kconfig entry does not exist, so the
qcom_smmu_impl_init() is never called.

So, let's fix this by always calling qcom_smmu_impl_init(). It does not
touch the smmu passed unless the device is a non-Qualcomm one. Make
ARM_SMMU select QCOM_SCM for ARCH_QCOM.

Fixes: 424953cf3c66 ("qcom_scm: hide Kconfig symbol")
Cc: Arnd Bergmann <arnd at arndb.de>
Reported-by: Daniel Lezcano <daniel.lezcano at linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/iommu/Kconfig                      | 1 +
 drivers/iommu/arm/arm-smmu/Makefile        | 3 +--
 drivers/iommu/arm/arm-smmu/arm-smmu-impl.c | 9 +++++++--
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index c5c71b7ab7e8..a4593e53fe7d 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -309,6 +309,7 @@ config ARM_SMMU
 	tristate "ARM Ltd. System MMU (SMMU) Support"
 	depends on ARM64 || ARM || (COMPILE_TEST && !GENERIC_ATOMIC64)
 	select IOMMU_API
+	select QCOM_SCM
 	select IOMMU_IO_PGTABLE_LPAE
 	select ARM_DMA_USE_IOMMU if ARM
 	help
diff --git a/drivers/iommu/arm/arm-smmu/Makefile b/drivers/iommu/arm/arm-smmu/Makefile
index b0cc01aa20c9..e240a7bcf310 100644
--- a/drivers/iommu/arm/arm-smmu/Makefile
+++ b/drivers/iommu/arm/arm-smmu/Makefile
@@ -1,5 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_QCOM_IOMMU) += qcom_iommu.o
 obj-$(CONFIG_ARM_SMMU) += arm_smmu.o
-arm_smmu-objs += arm-smmu.o arm-smmu-impl.o arm-smmu-nvidia.o
-arm_smmu-$(CONFIG_ARM_SMMU_QCOM) += arm-smmu-qcom.o
+arm_smmu-objs += arm-smmu.o arm-smmu-impl.o arm-smmu-nvidia.o arm-smmu-qcom.o
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c
index 2c25cce38060..8199185dd262 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c
@@ -215,8 +215,13 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu)
 	    of_device_is_compatible(np, "nvidia,tegra186-smmu"))
 		return nvidia_smmu_impl_init(smmu);
 
-	if (IS_ENABLED(CONFIG_ARM_SMMU_QCOM))
-		smmu = qcom_smmu_impl_init(smmu);
+	/*
+	 * qcom_smmu_impl_init() will not touch smmu if the device is not
+	 * a Qualcomm one.
+	 */
+	smmu = qcom_smmu_impl_init(smmu);
+	if (IS_ERR(smmu))
+		return smmu;
 
 	if (of_device_is_compatible(np, "marvell,ap806-smmu-500"))
 		smmu->impl = &mrvl_mmu500_impl;
-- 
2.30.2